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fix test_utf8.j #9

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StefanKarpinski opened this issue May 2, 2011 · 0 comments
Closed

fix test_utf8.j #9

StefanKarpinski opened this issue May 2, 2011 · 0 comments
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bug Indicates an unexpected problem or unintended behavior

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@StefanKarpinski
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This non-default test has been failing for quite some time, I think.

@ghost ghost assigned StefanKarpinski May 2, 2011
burrowsa pushed a commit to burrowsa/julia that referenced this issue Mar 24, 2014
jiahao added a commit that referenced this issue Jul 18, 2014
- A_mul_B
- Ac_mul_b_RFP
- qrp
- cholpfact, cholpfact!
- qrfact, qrfact!
- LinAlg.LUTridiagonal
- LinAlg.solve

Previously, callling any of these resulted in an `ERROR: ____ not defined`.

HT astrieanna/TypeCheck.jl/#9
StefanKarpinski pushed a commit that referenced this issue Feb 8, 2018
Add @compat as discussed in #8
StefanKarpinski pushed a commit that referenced this issue Feb 8, 2018
KristofferC pushed a commit that referenced this issue Feb 8, 2018
Keno added a commit that referenced this issue Jul 17, 2019
The bug here is a bit subtle, but perhaps best illustrated with
the included test case:
```
function f32579(x::Int64, b::Bool)
    if b
        x = nothing
    end
    if isa(x, Int64)
        y = x
    else
        y = x
    end
    if isa(y, Nothing)
        z = y
    else
        z = y
    end
    return z === nothing
end
```
The code just after SSA conversion looks like:
```
2  1 ─       goto #3 if not _3
3  2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
5  3 ┄ %3  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
   │   %4  = (%3 isa Main.Int64)::Bool
   └──       goto #5 if not %4
6  4 ─ %6  = π (%3, Int64)
   └──       goto #6
8  5 ─ %8  = π (%3, Nothing)
10 6 ┄ %9  = φ (#4 => %6, #5 => %8)::Union{Nothing, Int64}
   │   %10 = (%9 isa Main.Nothing)::Bool
   └──       goto #8 if not %10
11 7 ─ %12 = π (%9, Nothing)
   └──       goto #9
13 8 ─ %14 = π (%9, Int64)
15 9 ┄ %15 = φ (#7 => %12, #8 => %14)::Union{Nothing, Int64}
   │   %16 = (%15 === Main.nothing)::Bool
   └──       return %16
```
Now, we have special code in SROA (despite it not really being an
SROA transform) that looks at `===` and replaces
it by a nest of phis of booleans. The reasoning for this transform
is that it eliminates a use of a value where we only care about the
type and not the content, thus making it more likely that the value
will subsequently be eligible for SROA. In addition, while it goes
along resolving which values feed into any particular phi, it
accumulates and type conditions it encounters along the way.

Thus in the example above, something like the following happens:
- We look at %14, which πs to %9 with an Int64 constraint, so we only
  consider the #4 predecessor for %9 (due to the constraint), until
  we get to %3, where we again only consider the #1 predecessor,
  where we find the argument (of type Int64) and conclude the result
  is always false
- Now we pop the next item of the stack from our original phi, look
  at %12, which πs to %9 with a Nothing constraint.

At this point we used to terminate the search because we already looked
at %9. However, crucially, we looked at %9 only with an Int64 constraint,
so we missed the fact that `nothing` was in fact a possible value for this
phi. The result was a missing entry in the generated phi node:
```
1 ─       goto #3 if not b
2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
3 ┄ %3  = φ (#1 => false)::Bool
│   %4  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
│   %5  = (%4 isa Main.Int64)::Bool
└──       goto #5 if not %5
4 ─ %7  = π (%4, Int64)
└──       goto #6
5 ─ %9  = π (%4, Nothing)
6 ┄ %10 = φ (#4 => %3, #5 => %3)::Bool
│   %11 = φ (#4 => %7, #5 => %9)::Union{Nothing, Int64}
│   %12 = (%11 isa Main.Nothing)::Bool
└──       goto #8 if not %12
7 ─       goto #9
8 ─       nothing::Nothing
9 ┄ %16 = φ (#7 => %10, #8 => %10)::Bool
└──       return %16
```
(note the missing #2 predecessor in phi node %3), which would result
in an undefined value at runtime, though in this case LLVM would
have taken advantage of that to just return 0:
```
define i8 @julia_f32579_16051(i64, i8) {
top:
;  @ REPL[1]:15 within `f32579'
  ret i8 0
}
```
Compare this now to the optimized IR with this patch:
```
1 ─       goto #3 if not b
2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
3 ┄ %3  = φ (#2 => true, #1 => false)::Bool
│   %4  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
│   %5  = (%4 isa Main.Int64)::Bool
└──       goto #5 if not %5
4 ─ %7  = π (%4, Int64)
└──       goto #6
5 ─ %9  = π (%4, Nothing)
6 ┄ %10 = φ (#4 => %3, #5 => %3)::Bool
│   %11 = φ (#4 => %7, #5 => %9)::Union{Nothing, Int64}
│   %12 = (%11 isa Main.Nothing)::Bool
└──       goto #8 if not %12
7 ─       goto #9
8 ─       nothing::Nothing
9 ┄ %16 = φ (#7 => %10, #8 => %10)::Bool
└──       return %16
```
The %3 phi node has its missing entry and the generated LLVM code
correctly returns `b`:
```
define i8 @julia_f32579_16112(i64, i8) {
top:
  %2 = and i8 %1, 1
;  @ REPL[1]:15 within `f32579'
  ret i8 %2
}
```
Keno added a commit that referenced this issue Jul 17, 2019
The bug here is a bit subtle, but perhaps best illustrated with
the included test case:
```
function f32579(x::Int64, b::Bool)
    if b
        x = nothing
    end
    if isa(x, Int64)
        y = x
    else
        y = x
    end
    if isa(y, Nothing)
        z = y
    else
        z = y
    end
    return z === nothing
end
```
The code just after SSA conversion looks like:
```
2  1 ─       goto #3 if not _3
3  2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
5  3 ┄ %3  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
   │   %4  = (%3 isa Main.Int64)::Bool
   └──       goto #5 if not %4
6  4 ─ %6  = π (%3, Int64)
   └──       goto #6
8  5 ─ %8  = π (%3, Nothing)
10 6 ┄ %9  = φ (#4 => %6, #5 => %8)::Union{Nothing, Int64}
   │   %10 = (%9 isa Main.Nothing)::Bool
   └──       goto #8 if not %10
11 7 ─ %12 = π (%9, Nothing)
   └──       goto #9
13 8 ─ %14 = π (%9, Int64)
15 9 ┄ %15 = φ (#7 => %12, #8 => %14)::Union{Nothing, Int64}
   │   %16 = (%15 === Main.nothing)::Bool
   └──       return %16
```
Now, we have special code in SROA (despite it not really being an
SROA transform) that looks at `===` and replaces
it by a nest of phis of booleans. The reasoning for this transform
is that it eliminates a use of a value where we only care about the
type and not the content, thus making it more likely that the value
will subsequently be eligible for SROA. In addition, while it goes
along resolving which values feed into any particular phi, it
accumulates and type conditions it encounters along the way.

Thus in the example above, something like the following happens:
- We look at %14, which πs to %9 with an Int64 constraint, so we only
  consider the #4 predecessor for %9 (due to the constraint), until
  we get to %3, where we again only consider the #1 predecessor,
  where we find the argument (of type Int64) and conclude the result
  is always false
- Now we pop the next item of the stack from our original phi, look
  at %12, which πs to %9 with a Nothing constraint.

At this point we used to terminate the search because we already looked
at %9. However, crucially, we looked at %9 only with an Int64 constraint,
so we missed the fact that `nothing` was in fact a possible value for this
phi. The result was a missing entry in the generated phi node:
```
1 ─       goto #3 if not b
2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
3 ┄ %3  = φ (#1 => false)::Bool
│   %4  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
│   %5  = (%4 isa Main.Int64)::Bool
└──       goto #5 if not %5
4 ─ %7  = π (%4, Int64)
└──       goto #6
5 ─ %9  = π (%4, Nothing)
6 ┄ %10 = φ (#4 => %3, #5 => %3)::Bool
│   %11 = φ (#4 => %7, #5 => %9)::Union{Nothing, Int64}
│   %12 = (%11 isa Main.Nothing)::Bool
└──       goto #8 if not %12
7 ─       goto #9
8 ─       nothing::Nothing
9 ┄ %16 = φ (#7 => %10, #8 => %10)::Bool
└──       return %16
```
(note the missing #2 predecessor in phi node %3), which would result
in an undefined value at runtime, though in this case LLVM would
have taken advantage of that to just return 0:
```
define i8 @julia_f32579_16051(i64, i8) {
top:
;  @ REPL[1]:15 within `f32579'
  ret i8 0
}
```
Compare this now to the optimized IR with this patch:
```
1 ─       goto #3 if not b
2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
3 ┄ %3  = φ (#2 => true, #1 => false)::Bool
│   %4  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
│   %5  = (%4 isa Main.Int64)::Bool
└──       goto #5 if not %5
4 ─ %7  = π (%4, Int64)
└──       goto #6
5 ─ %9  = π (%4, Nothing)
6 ┄ %10 = φ (#4 => %3, #5 => %3)::Bool
│   %11 = φ (#4 => %7, #5 => %9)::Union{Nothing, Int64}
│   %12 = (%11 isa Main.Nothing)::Bool
└──       goto #8 if not %12
7 ─       goto #9
8 ─       nothing::Nothing
9 ┄ %16 = φ (#7 => %10, #8 => %10)::Bool
└──       return %16
```
The %3 phi node has its missing entry and the generated LLVM code
correctly returns `b`:
```
define i8 @julia_f32579_16112(i64, i8) {
top:
  %2 = and i8 %1, 1
;  @ REPL[1]:15 within `f32579'
  ret i8 %2
}
```
Keno added a commit that referenced this issue Jul 17, 2019
The bug here is a bit subtle, but perhaps best illustrated with
the included test case:
```
function f32579(x::Int64, b::Bool)
    if b
        x = nothing
    end
    if isa(x, Int64)
        y = x
    else
        y = x
    end
    if isa(y, Nothing)
        z = y
    else
        z = y
    end
    return z === nothing
end
```
The code just after SSA conversion looks like:
```
2  1 ─       goto #3 if not _3
3  2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
5  3 ┄ %3  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
   │   %4  = (%3 isa Main.Int64)::Bool
   └──       goto #5 if not %4
6  4 ─ %6  = π (%3, Int64)
   └──       goto #6
8  5 ─ %8  = π (%3, Nothing)
10 6 ┄ %9  = φ (#4 => %6, #5 => %8)::Union{Nothing, Int64}
   │   %10 = (%9 isa Main.Nothing)::Bool
   └──       goto #8 if not %10
11 7 ─ %12 = π (%9, Nothing)
   └──       goto #9
13 8 ─ %14 = π (%9, Int64)
15 9 ┄ %15 = φ (#7 => %12, #8 => %14)::Union{Nothing, Int64}
   │   %16 = (%15 === Main.nothing)::Bool
   └──       return %16
```
Now, we have special code in SROA (despite it not really being an
SROA transform) that looks at `===` and replaces
it by a nest of phis of booleans. The reasoning for this transform
is that it eliminates a use of a value where we only care about the
type and not the content, thus making it more likely that the value
will subsequently be eligible for SROA. In addition, while it goes
along resolving which values feed into any particular phi, it
accumulates and type conditions it encounters along the way.

Thus in the example above, something like the following happens:
- We look at %14, which πs to %9 with an Int64 constraint, so we only
  consider the #4 predecessor for %9 (due to the constraint), until
  we get to %3, where we again only consider the #1 predecessor,
  where we find the argument (of type Int64) and conclude the result
  is always false
- Now we pop the next item of the stack from our original phi, look
  at %12, which πs to %9 with a Nothing constraint.

At this point we used to terminate the search because we already looked
at %9. However, crucially, we looked at %9 only with an Int64 constraint,
so we missed the fact that `nothing` was in fact a possible value for this
phi. The result was a missing entry in the generated phi node:
```
1 ─       goto #3 if not b
2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
3 ┄ %3  = φ (#1 => false)::Bool
│   %4  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
│   %5  = (%4 isa Main.Int64)::Bool
└──       goto #5 if not %5
4 ─ %7  = π (%4, Int64)
└──       goto #6
5 ─ %9  = π (%4, Nothing)
6 ┄ %10 = φ (#4 => %3, #5 => %3)::Bool
│   %11 = φ (#4 => %7, #5 => %9)::Union{Nothing, Int64}
│   %12 = (%11 isa Main.Nothing)::Bool
└──       goto #8 if not %12
7 ─       goto #9
8 ─       nothing::Nothing
9 ┄ %16 = φ (#7 => %10, #8 => %10)::Bool
└──       return %16
```
(note the missing #2 predecessor in phi node %3), which would result
in an undefined value at runtime, though in this case LLVM would
have taken advantage of that to just return 0:
```
define i8 @julia_f32579_16051(i64, i8) {
top:
;  @ REPL[1]:15 within `f32579'
  ret i8 0
}
```
Compare this now to the optimized IR with this patch:
```
1 ─       goto #3 if not b
2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
3 ┄ %3  = φ (#2 => true, #1 => false)::Bool
│   %4  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
│   %5  = (%4 isa Main.Int64)::Bool
└──       goto #5 if not %5
4 ─ %7  = π (%4, Int64)
└──       goto #6
5 ─ %9  = π (%4, Nothing)
6 ┄ %10 = φ (#4 => %3, #5 => %3)::Bool
│   %11 = φ (#4 => %7, #5 => %9)::Union{Nothing, Int64}
│   %12 = (%11 isa Main.Nothing)::Bool
└──       goto #8 if not %12
7 ─       goto #9
8 ─       nothing::Nothing
9 ┄ %16 = φ (#7 => %10, #8 => %10)::Bool
└──       return %16
```
The %3 phi node has its missing entry and the generated LLVM code
correctly returns `b`:
```
define i8 @julia_f32579_16112(i64, i8) {
top:
  %2 = and i8 %1, 1
;  @ REPL[1]:15 within `f32579'
  ret i8 %2
}
```
KristofferC pushed a commit that referenced this issue Jul 20, 2019
The bug here is a bit subtle, but perhaps best illustrated with
the included test case:
```
function f32579(x::Int64, b::Bool)
    if b
        x = nothing
    end
    if isa(x, Int64)
        y = x
    else
        y = x
    end
    if isa(y, Nothing)
        z = y
    else
        z = y
    end
    return z === nothing
end
```
The code just after SSA conversion looks like:
```
2  1 ─       goto #3 if not _3
3  2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
5  3 ┄ %3  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
   │   %4  = (%3 isa Main.Int64)::Bool
   └──       goto #5 if not %4
6  4 ─ %6  = π (%3, Int64)
   └──       goto #6
8  5 ─ %8  = π (%3, Nothing)
10 6 ┄ %9  = φ (#4 => %6, #5 => %8)::Union{Nothing, Int64}
   │   %10 = (%9 isa Main.Nothing)::Bool
   └──       goto #8 if not %10
11 7 ─ %12 = π (%9, Nothing)
   └──       goto #9
13 8 ─ %14 = π (%9, Int64)
15 9 ┄ %15 = φ (#7 => %12, #8 => %14)::Union{Nothing, Int64}
   │   %16 = (%15 === Main.nothing)::Bool
   └──       return %16
```
Now, we have special code in SROA (despite it not really being an
SROA transform) that looks at `===` and replaces
it by a nest of phis of booleans. The reasoning for this transform
is that it eliminates a use of a value where we only care about the
type and not the content, thus making it more likely that the value
will subsequently be eligible for SROA. In addition, while it goes
along resolving which values feed into any particular phi, it
accumulates and type conditions it encounters along the way.

Thus in the example above, something like the following happens:
- We look at %14, which πs to %9 with an Int64 constraint, so we only
  consider the #4 predecessor for %9 (due to the constraint), until
  we get to %3, where we again only consider the #1 predecessor,
  where we find the argument (of type Int64) and conclude the result
  is always false
- Now we pop the next item of the stack from our original phi, look
  at %12, which πs to %9 with a Nothing constraint.

At this point we used to terminate the search because we already looked
at %9. However, crucially, we looked at %9 only with an Int64 constraint,
so we missed the fact that `nothing` was in fact a possible value for this
phi. The result was a missing entry in the generated phi node:
```
1 ─       goto #3 if not b
2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
3 ┄ %3  = φ (#1 => false)::Bool
│   %4  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
│   %5  = (%4 isa Main.Int64)::Bool
└──       goto #5 if not %5
4 ─ %7  = π (%4, Int64)
└──       goto #6
5 ─ %9  = π (%4, Nothing)
6 ┄ %10 = φ (#4 => %3, #5 => %3)::Bool
│   %11 = φ (#4 => %7, #5 => %9)::Union{Nothing, Int64}
│   %12 = (%11 isa Main.Nothing)::Bool
└──       goto #8 if not %12
7 ─       goto #9
8 ─       nothing::Nothing
9 ┄ %16 = φ (#7 => %10, #8 => %10)::Bool
└──       return %16
```
(note the missing #2 predecessor in phi node %3), which would result
in an undefined value at runtime, though in this case LLVM would
have taken advantage of that to just return 0:
```
define i8 @julia_f32579_16051(i64, i8) {
top:
;  @ REPL[1]:15 within `f32579'
  ret i8 0
}
```
Compare this now to the optimized IR with this patch:
```
1 ─       goto #3 if not b
2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
3 ┄ %3  = φ (#2 => true, #1 => false)::Bool
│   %4  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
│   %5  = (%4 isa Main.Int64)::Bool
└──       goto #5 if not %5
4 ─ %7  = π (%4, Int64)
└──       goto #6
5 ─ %9  = π (%4, Nothing)
6 ┄ %10 = φ (#4 => %3, #5 => %3)::Bool
│   %11 = φ (#4 => %7, #5 => %9)::Union{Nothing, Int64}
│   %12 = (%11 isa Main.Nothing)::Bool
└──       goto #8 if not %12
7 ─       goto #9
8 ─       nothing::Nothing
9 ┄ %16 = φ (#7 => %10, #8 => %10)::Bool
└──       return %16
```
The %3 phi node has its missing entry and the generated LLVM code
correctly returns `b`:
```
define i8 @julia_f32579_16112(i64, i8) {
top:
  %2 = and i8 %1, 1
;  @ REPL[1]:15 within `f32579'
  ret i8 %2
}
```

(cherry picked from commit 0a12944)
KristofferC pushed a commit that referenced this issue Aug 26, 2019
The bug here is a bit subtle, but perhaps best illustrated with
the included test case:
```
function f32579(x::Int64, b::Bool)
    if b
        x = nothing
    end
    if isa(x, Int64)
        y = x
    else
        y = x
    end
    if isa(y, Nothing)
        z = y
    else
        z = y
    end
    return z === nothing
end
```
The code just after SSA conversion looks like:
```
2  1 ─       goto #3 if not _3
3  2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
5  3 ┄ %3  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
   │   %4  = (%3 isa Main.Int64)::Bool
   └──       goto #5 if not %4
6  4 ─ %6  = π (%3, Int64)
   └──       goto #6
8  5 ─ %8  = π (%3, Nothing)
10 6 ┄ %9  = φ (#4 => %6, #5 => %8)::Union{Nothing, Int64}
   │   %10 = (%9 isa Main.Nothing)::Bool
   └──       goto #8 if not %10
11 7 ─ %12 = π (%9, Nothing)
   └──       goto #9
13 8 ─ %14 = π (%9, Int64)
15 9 ┄ %15 = φ (#7 => %12, #8 => %14)::Union{Nothing, Int64}
   │   %16 = (%15 === Main.nothing)::Bool
   └──       return %16
```
Now, we have special code in SROA (despite it not really being an
SROA transform) that looks at `===` and replaces
it by a nest of phis of booleans. The reasoning for this transform
is that it eliminates a use of a value where we only care about the
type and not the content, thus making it more likely that the value
will subsequently be eligible for SROA. In addition, while it goes
along resolving which values feed into any particular phi, it
accumulates and type conditions it encounters along the way.

Thus in the example above, something like the following happens:
- We look at %14, which πs to %9 with an Int64 constraint, so we only
  consider the #4 predecessor for %9 (due to the constraint), until
  we get to %3, where we again only consider the #1 predecessor,
  where we find the argument (of type Int64) and conclude the result
  is always false
- Now we pop the next item of the stack from our original phi, look
  at %12, which πs to %9 with a Nothing constraint.

At this point we used to terminate the search because we already looked
at %9. However, crucially, we looked at %9 only with an Int64 constraint,
so we missed the fact that `nothing` was in fact a possible value for this
phi. The result was a missing entry in the generated phi node:
```
1 ─       goto #3 if not b
2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
3 ┄ %3  = φ (#1 => false)::Bool
│   %4  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
│   %5  = (%4 isa Main.Int64)::Bool
└──       goto #5 if not %5
4 ─ %7  = π (%4, Int64)
└──       goto #6
5 ─ %9  = π (%4, Nothing)
6 ┄ %10 = φ (#4 => %3, #5 => %3)::Bool
│   %11 = φ (#4 => %7, #5 => %9)::Union{Nothing, Int64}
│   %12 = (%11 isa Main.Nothing)::Bool
└──       goto #8 if not %12
7 ─       goto #9
8 ─       nothing::Nothing
9 ┄ %16 = φ (#7 => %10, #8 => %10)::Bool
└──       return %16
```
(note the missing #2 predecessor in phi node %3), which would result
in an undefined value at runtime, though in this case LLVM would
have taken advantage of that to just return 0:
```
define i8 @julia_f32579_16051(i64, i8) {
top:
;  @ REPL[1]:15 within `f32579'
  ret i8 0
}
```
Compare this now to the optimized IR with this patch:
```
1 ─       goto #3 if not b
2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
3 ┄ %3  = φ (#2 => true, #1 => false)::Bool
│   %4  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
│   %5  = (%4 isa Main.Int64)::Bool
└──       goto #5 if not %5
4 ─ %7  = π (%4, Int64)
└──       goto #6
5 ─ %9  = π (%4, Nothing)
6 ┄ %10 = φ (#4 => %3, #5 => %3)::Bool
│   %11 = φ (#4 => %7, #5 => %9)::Union{Nothing, Int64}
│   %12 = (%11 isa Main.Nothing)::Bool
└──       goto #8 if not %12
7 ─       goto #9
8 ─       nothing::Nothing
9 ┄ %16 = φ (#7 => %10, #8 => %10)::Bool
└──       return %16
```
The %3 phi node has its missing entry and the generated LLVM code
correctly returns `b`:
```
define i8 @julia_f32579_16112(i64, i8) {
top:
  %2 = and i8 %1, 1
;  @ REPL[1]:15 within `f32579'
  ret i8 %2
}
```

(cherry picked from commit 0a12944)
KristofferC pushed a commit that referenced this issue Aug 26, 2019
The bug here is a bit subtle, but perhaps best illustrated with
the included test case:
```
function f32579(x::Int64, b::Bool)
    if b
        x = nothing
    end
    if isa(x, Int64)
        y = x
    else
        y = x
    end
    if isa(y, Nothing)
        z = y
    else
        z = y
    end
    return z === nothing
end
```
The code just after SSA conversion looks like:
```
2  1 ─       goto #3 if not _3
3  2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
5  3 ┄ %3  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
   │   %4  = (%3 isa Main.Int64)::Bool
   └──       goto #5 if not %4
6  4 ─ %6  = π (%3, Int64)
   └──       goto #6
8  5 ─ %8  = π (%3, Nothing)
10 6 ┄ %9  = φ (#4 => %6, #5 => %8)::Union{Nothing, Int64}
   │   %10 = (%9 isa Main.Nothing)::Bool
   └──       goto #8 if not %10
11 7 ─ %12 = π (%9, Nothing)
   └──       goto #9
13 8 ─ %14 = π (%9, Int64)
15 9 ┄ %15 = φ (#7 => %12, #8 => %14)::Union{Nothing, Int64}
   │   %16 = (%15 === Main.nothing)::Bool
   └──       return %16
```
Now, we have special code in SROA (despite it not really being an
SROA transform) that looks at `===` and replaces
it by a nest of phis of booleans. The reasoning for this transform
is that it eliminates a use of a value where we only care about the
type and not the content, thus making it more likely that the value
will subsequently be eligible for SROA. In addition, while it goes
along resolving which values feed into any particular phi, it
accumulates and type conditions it encounters along the way.

Thus in the example above, something like the following happens:
- We look at %14, which πs to %9 with an Int64 constraint, so we only
  consider the #4 predecessor for %9 (due to the constraint), until
  we get to %3, where we again only consider the #1 predecessor,
  where we find the argument (of type Int64) and conclude the result
  is always false
- Now we pop the next item of the stack from our original phi, look
  at %12, which πs to %9 with a Nothing constraint.

At this point we used to terminate the search because we already looked
at %9. However, crucially, we looked at %9 only with an Int64 constraint,
so we missed the fact that `nothing` was in fact a possible value for this
phi. The result was a missing entry in the generated phi node:
```
1 ─       goto #3 if not b
2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
3 ┄ %3  = φ (#1 => false)::Bool
│   %4  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
│   %5  = (%4 isa Main.Int64)::Bool
└──       goto #5 if not %5
4 ─ %7  = π (%4, Int64)
└──       goto #6
5 ─ %9  = π (%4, Nothing)
6 ┄ %10 = φ (#4 => %3, #5 => %3)::Bool
│   %11 = φ (#4 => %7, #5 => %9)::Union{Nothing, Int64}
│   %12 = (%11 isa Main.Nothing)::Bool
└──       goto #8 if not %12
7 ─       goto #9
8 ─       nothing::Nothing
9 ┄ %16 = φ (#7 => %10, #8 => %10)::Bool
└──       return %16
```
(note the missing #2 predecessor in phi node %3), which would result
in an undefined value at runtime, though in this case LLVM would
have taken advantage of that to just return 0:
```
define i8 @julia_f32579_16051(i64, i8) {
top:
;  @ REPL[1]:15 within `f32579'
  ret i8 0
}
```
Compare this now to the optimized IR with this patch:
```
1 ─       goto #3 if not b
2 ─ %2  = Main.nothing::Core.Compiler.Const(nothing, false)
3 ┄ %3  = φ (#2 => true, #1 => false)::Bool
│   %4  = φ (#2 => %2, #1 => _2)::Union{Nothing, Int64}
│   %5  = (%4 isa Main.Int64)::Bool
└──       goto #5 if not %5
4 ─ %7  = π (%4, Int64)
└──       goto #6
5 ─ %9  = π (%4, Nothing)
6 ┄ %10 = φ (#4 => %3, #5 => %3)::Bool
│   %11 = φ (#4 => %7, #5 => %9)::Union{Nothing, Int64}
│   %12 = (%11 isa Main.Nothing)::Bool
└──       goto #8 if not %12
7 ─       goto #9
8 ─       nothing::Nothing
9 ┄ %16 = φ (#7 => %10, #8 => %10)::Bool
└──       return %16
```
The %3 phi node has its missing entry and the generated LLVM code
correctly returns `b`:
```
define i8 @julia_f32579_16112(i64, i8) {
top:
  %2 = and i8 %1, 1
;  @ REPL[1]:15 within `f32579'
  ret i8 %2
}
```

(cherry picked from commit 0a12944)
aviatesk added a commit that referenced this issue Oct 5, 2022
This commit tries to fix and improve performance for calling keyword
funcs whose arguments types are not fully known but `@nospecialize`-d.

The final result would look like (this particular example is taken from
our Julia-level compiler implementation):
```julia
abstract type CallInfo end
struct NoCallInfo <: CallInfo end
struct NewInstruction
    stmt::Any
    type::Any
    info::CallInfo
    line::Union{Int32,Nothing} # if nothing, copy the line from previous statement in the insertion location
    flag::Union{UInt8,Nothing} # if nothing, IR flags will be recomputed on insertion
    function NewInstruction(@nospecialize(stmt), @nospecialize(type), @nospecialize(info::CallInfo),
                            line::Union{Int32,Nothing}, flag::Union{UInt8,Nothing})
        return new(stmt, type, info, line, flag)
    end
end
@nospecialize
function NewInstruction(newinst::NewInstruction;
    stmt=newinst.stmt,
    type=newinst.type,
    info::CallInfo=newinst.info,
    line::Union{Int32,Nothing}=newinst.line,
    flag::Union{UInt8,Nothing}=newinst.flag)
    return NewInstruction(stmt, type, info, line, flag)
end
@Specialize

using BenchmarkTools
struct VirtualKwargs
    stmt::Any
    type::Any
    info::CallInfo
end
vkws = VirtualKwargs(nothing, Any, NoCallInfo())
newinst = NewInstruction(nothing, Any, NoCallInfo(), nothing, nothing)
runner(newinst, vkws) = NewInstruction(newinst; vkws.stmt, vkws.type, vkws.info)
@benchmark runner($newinst, $vkws)
```

> on master
```
BenchmarkTools.Trial: 10000 samples with 186 evaluations.
 Range (min … max):  559.898 ns …   4.173 μs  ┊ GC (min … max): 0.00% … 85.29%
 Time  (median):     605.608 ns               ┊ GC (median):    0.00%
 Time  (mean ± σ):   638.170 ns ± 125.080 ns  ┊ GC (mean ± σ):  0.06% ±  0.85%

  █▇▂▆▄  ▁█▇▄▂                                                  ▂
  ██████▅██████▇▇▇██████▇▇▇▆▆▅▄▅▄▂▄▄▅▇▆▆▆▆▆▅▆▆▄▄▅▅▄▃▄▄▄▅▃▅▅▆▅▆▆ █
  560 ns        Histogram: log(frequency) by time       1.23 μs <

 Memory estimate: 32 bytes, allocs estimate: 2.
```

> on this commit
```julia
BenchmarkTools.Trial: 10000 samples with 1000 evaluations.
 Range (min … max):  3.080 ns … 83.177 ns  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     3.098 ns              ┊ GC (median):    0.00%
 Time  (mean ± σ):   3.118 ns ±  0.885 ns  ┊ GC (mean ± σ):  0.00% ± 0.00%

       ▂▅▇█▆▅▄▂
  ▂▄▆▆▇████████▆▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁▁▂▂▂▁▂▂▂▂▂▂▁▁▂▁▂▂▂▂▂▂▂▂▂ ▃
  3.08 ns        Histogram: frequency by time        3.19 ns <

 Memory estimate: 0 bytes, allocs estimate: 0.
```

So for this particular case it achieves roughly 200x speed up.
This is because this commit allows inlining of a call to keyword sorter
as well as removal of `NamedTuple` call.

Especially this commit is composed of the following improvements:
- add early return case for `structdiff`:
  This change improves the return type inference for a case when
  compared `NamedTuple`s are type unstable but there is no difference
  in their names, e.g. given two `NamedTuple{(:a,:b),T} where T<:Tuple{Any,Any}`s.
  And in such case the optimizer will remove `structdiff` and succeeding
  `pairs` calls, letting the keyword sorter to be inlined.
- add special SROA handling for `NamedTuple` generated by keyword sorter:
  With the change on `structdiff`, IR for a call with type-unstable
  keyword arguments after inlining would look like:
  ```
  %1 = tuple(a, b, c)::Tuple{Any, Any, Any}
  %2 = NamedTuple{(:a, :b, :c)(%1)::NamedTuple{(:a, :b, :c), _A} where _A<:Tuple{Any, Any, Any}
  %3  = Core.getfield(%2, :a)::Any
  %4  = Core.getfield(%2, :b)::Any
  %5  = Core.getfield(%2, :c)::Any
  [... other body of the keyword func ...]
  ```
  We can implement a bit hacky special handling within our SROA pass
  that checks if this definition (%2) is partly well-known `NamedTuple`
  construction, where its names are fully known, and also checks if its
  call argument (%1) is fully-known `tuple` call. In a case when the
  length of the `NamedTuple` names and the length of the arguments for
  the `tuple` call, we can safely replace those `getfield` calls with
  the corresponding `tuple` call argument, while letting the later DCE
  pass to delete the constructions of tuple and named-tuple altogether.

With these changes, the IR for the example `NewInstruction` constructor
is fairly optimized, like:
```julia
julia> Base.code_ircode((NewInstruction,Any,Any,CallInfo)) do newinst, stmt, type, info
           NewInstruction(newinst; stmt, type, info)
       end |> only
2 1 ── %1  = Base.getfield(_2, :line)::Union{Nothing, Int32}                    │╻╷  Type##kw
  │    %2  = Base.getfield(_2, :flag)::Union{Nothing, UInt8}                    ││┃   getproperty
  │    %3  = (isa)(%1, Nothing)::Bool                                           ││
  │    %4  = (isa)(%2, Nothing)::Bool                                           ││
  │    %5  = (Core.Intrinsics.and_int)(%3, %4)::Bool                            ││
  └───       goto #3 if not %5                                                  ││
  2 ── %7  = %new(Main.NewInstruction, _3, _4, _5, nothing, nothing)::NewInstruction   NewInstruction
  └───       goto #10                                                           ││
  3 ── %9  = (isa)(%1, Int32)::Bool                                             ││
  │    %10 = (isa)(%2, Nothing)::Bool                                           ││
  │    %11 = (Core.Intrinsics.and_int)(%9, %10)::Bool                           ││
  └───       goto #5 if not %11                                                 ││
  4 ── %13 = π (%1, Int32)                                                      ││
  │    %14 = %new(Main.NewInstruction, _3, _4, _5, %13, nothing)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  5 ── %16 = (isa)(%1, Nothing)::Bool                                           ││
  │    %17 = (isa)(%2, UInt8)::Bool                                             ││
  │    %18 = (Core.Intrinsics.and_int)(%16, %17)::Bool                          ││
  └───       goto #7 if not %18                                                 ││
  6 ── %20 = π (%2, UInt8)                                                      ││
  │    %21 = %new(Main.NewInstruction, _3, _4, _5, nothing, %20)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  7 ── %23 = (isa)(%1, Int32)::Bool                                             ││
  │    %24 = (isa)(%2, UInt8)::Bool                                             ││
  │    %25 = (Core.Intrinsics.and_int)(%23, %24)::Bool                          ││
  └───       goto #9 if not %25                                                 ││
  8 ── %27 = π (%1, Int32)                                                      ││
  │    %28 = π (%2, UInt8)                                                      ││
  │    %29 = %new(Main.NewInstruction, _3, _4, _5, %27, %28)::NewInstruction    │││╻   NewInstruction
  └───       goto #10                                                           ││
  9 ──       Core.throw(ErrorException("fatal error in type inference (type bound)"))::Union{}
  └───       unreachable                                                        ││
  10 ┄ %33 = φ (#2 => %7, #4 => %14, #6 => %21, #8 => %29)::NewInstruction      ││
  └───       goto #11                                                           ││
  11 ─       return %33                                                         │
   => NewInstruction
```
aviatesk added a commit that referenced this issue Oct 5, 2022
This commit tries to fix and improve performance for calling keyword
funcs whose arguments types are not fully known but `@nospecialize`-d.

The final result would look like (this particular example is taken from
our Julia-level compiler implementation):
```julia
abstract type CallInfo end
struct NoCallInfo <: CallInfo end
struct NewInstruction
    stmt::Any
    type::Any
    info::CallInfo
    line::Union{Int32,Nothing} # if nothing, copy the line from previous statement in the insertion location
    flag::Union{UInt8,Nothing} # if nothing, IR flags will be recomputed on insertion
    function NewInstruction(@nospecialize(stmt), @nospecialize(type), @nospecialize(info::CallInfo),
                            line::Union{Int32,Nothing}, flag::Union{UInt8,Nothing})
        return new(stmt, type, info, line, flag)
    end
end
@nospecialize
function NewInstruction(newinst::NewInstruction;
    stmt=newinst.stmt,
    type=newinst.type,
    info::CallInfo=newinst.info,
    line::Union{Int32,Nothing}=newinst.line,
    flag::Union{UInt8,Nothing}=newinst.flag)
    return NewInstruction(stmt, type, info, line, flag)
end
@Specialize

using BenchmarkTools
struct VirtualKwargs
    stmt::Any
    type::Any
    info::CallInfo
end
vkws = VirtualKwargs(nothing, Any, NoCallInfo())
newinst = NewInstruction(nothing, Any, NoCallInfo(), nothing, nothing)
runner(newinst, vkws) = NewInstruction(newinst; vkws.stmt, vkws.type, vkws.info)
@benchmark runner($newinst, $vkws)
```

> on master
```
BenchmarkTools.Trial: 10000 samples with 186 evaluations.
 Range (min … max):  559.898 ns …   4.173 μs  ┊ GC (min … max): 0.00% … 85.29%
 Time  (median):     605.608 ns               ┊ GC (median):    0.00%
 Time  (mean ± σ):   638.170 ns ± 125.080 ns  ┊ GC (mean ± σ):  0.06% ±  0.85%

  █▇▂▆▄  ▁█▇▄▂                                                  ▂
  ██████▅██████▇▇▇██████▇▇▇▆▆▅▄▅▄▂▄▄▅▇▆▆▆▆▆▅▆▆▄▄▅▅▄▃▄▄▄▅▃▅▅▆▅▆▆ █
  560 ns        Histogram: log(frequency) by time       1.23 μs <

 Memory estimate: 32 bytes, allocs estimate: 2.
```

> on this commit
```julia
BenchmarkTools.Trial: 10000 samples with 1000 evaluations.
 Range (min … max):  3.080 ns … 83.177 ns  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     3.098 ns              ┊ GC (median):    0.00%
 Time  (mean ± σ):   3.118 ns ±  0.885 ns  ┊ GC (mean ± σ):  0.00% ± 0.00%

       ▂▅▇█▆▅▄▂
  ▂▄▆▆▇████████▆▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁▁▂▂▂▁▂▂▂▂▂▂▁▁▂▁▂▂▂▂▂▂▂▂▂ ▃
  3.08 ns        Histogram: frequency by time        3.19 ns <

 Memory estimate: 0 bytes, allocs estimate: 0.
```

So for this particular case it achieves roughly 200x speed up.
This is because this commit allows inlining of a call to keyword sorter
as well as removal of `NamedTuple` call.

Especially this commit is composed of the following improvements:
- add early return case for `structdiff`:
  This change improves the return type inference for a case when
  compared `NamedTuple`s are type unstable but there is no difference
  in their names, e.g. given two `NamedTuple{(:a,:b),T} where T<:Tuple{Any,Any}`s.
  And in such case the optimizer will remove `structdiff` and succeeding
  `pairs` calls, letting the keyword sorter to be inlined.
- add special SROA handling for `NamedTuple` generated by keyword sorter:
  With the change on `structdiff`, IR for a call with type-unstable
  keyword arguments after inlining would look like:
  ```
  %1 = tuple(a, b, c)::Tuple{Any, Any, Any}
  %2 = NamedTuple{(:a, :b, :c)(%1)::NamedTuple{(:a, :b, :c), _A} where _A<:Tuple{Any, Any, Any}
  %3  = Core.getfield(%2, :a)::Any
  %4  = Core.getfield(%2, :b)::Any
  %5  = Core.getfield(%2, :c)::Any
  [... other body of the keyword func ...]
  ```
  We can implement a bit hacky special handling within our SROA pass
  that checks if this definition (%2) is partly well-known `NamedTuple`
  construction, where its names are fully known, and also checks if its
  call argument (%1) is fully-known `tuple` call. In a case when the
  length of the `NamedTuple` names and the length of the arguments for
  the `tuple` call, we can safely replace those `getfield` calls with
  the corresponding `tuple` call argument, while letting the later DCE
  pass to delete the constructions of tuple and named-tuple altogether.

With these changes, the IR for the example `NewInstruction` constructor
is fairly optimized, like:
```julia
julia> Base.code_ircode((NewInstruction,Any,Any,CallInfo)) do newinst, stmt, type, info
           NewInstruction(newinst; stmt, type, info)
       end |> only
2 1 ── %1  = Base.getfield(_2, :line)::Union{Nothing, Int32}                    │╻╷  Type##kw
  │    %2  = Base.getfield(_2, :flag)::Union{Nothing, UInt8}                    ││┃   getproperty
  │    %3  = (isa)(%1, Nothing)::Bool                                           ││
  │    %4  = (isa)(%2, Nothing)::Bool                                           ││
  │    %5  = (Core.Intrinsics.and_int)(%3, %4)::Bool                            ││
  └───       goto #3 if not %5                                                  ││
  2 ── %7  = %new(Main.NewInstruction, _3, _4, _5, nothing, nothing)::NewInstruction   NewInstruction
  └───       goto #10                                                           ││
  3 ── %9  = (isa)(%1, Int32)::Bool                                             ││
  │    %10 = (isa)(%2, Nothing)::Bool                                           ││
  │    %11 = (Core.Intrinsics.and_int)(%9, %10)::Bool                           ││
  └───       goto #5 if not %11                                                 ││
  4 ── %13 = π (%1, Int32)                                                      ││
  │    %14 = %new(Main.NewInstruction, _3, _4, _5, %13, nothing)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  5 ── %16 = (isa)(%1, Nothing)::Bool                                           ││
  │    %17 = (isa)(%2, UInt8)::Bool                                             ││
  │    %18 = (Core.Intrinsics.and_int)(%16, %17)::Bool                          ││
  └───       goto #7 if not %18                                                 ││
  6 ── %20 = π (%2, UInt8)                                                      ││
  │    %21 = %new(Main.NewInstruction, _3, _4, _5, nothing, %20)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  7 ── %23 = (isa)(%1, Int32)::Bool                                             ││
  │    %24 = (isa)(%2, UInt8)::Bool                                             ││
  │    %25 = (Core.Intrinsics.and_int)(%23, %24)::Bool                          ││
  └───       goto #9 if not %25                                                 ││
  8 ── %27 = π (%1, Int32)                                                      ││
  │    %28 = π (%2, UInt8)                                                      ││
  │    %29 = %new(Main.NewInstruction, _3, _4, _5, %27, %28)::NewInstruction    │││╻   NewInstruction
  └───       goto #10                                                           ││
  9 ──       Core.throw(ErrorException("fatal error in type inference (type bound)"))::Union{}
  └───       unreachable                                                        ││
  10 ┄ %33 = φ (#2 => %7, #4 => %14, #6 => %21, #8 => %29)::NewInstruction      ││
  └───       goto #11                                                           ││
  11 ─       return %33                                                         │
   => NewInstruction
```
aviatesk added a commit that referenced this issue Oct 7, 2022
This commit tries to fix and improve performance for calling keyword
funcs whose arguments types are not fully known but `@nospecialize`-d.

The final result would look like (this particular example is taken from
our Julia-level compiler implementation):
```julia
abstract type CallInfo end
struct NoCallInfo <: CallInfo end
struct NewInstruction
    stmt::Any
    type::Any
    info::CallInfo
    line::Union{Int32,Nothing} # if nothing, copy the line from previous statement in the insertion location
    flag::Union{UInt8,Nothing} # if nothing, IR flags will be recomputed on insertion
    function NewInstruction(@nospecialize(stmt), @nospecialize(type), @nospecialize(info::CallInfo),
                            line::Union{Int32,Nothing}, flag::Union{UInt8,Nothing})
        return new(stmt, type, info, line, flag)
    end
end
@nospecialize
function NewInstruction(newinst::NewInstruction;
    stmt=newinst.stmt,
    type=newinst.type,
    info::CallInfo=newinst.info,
    line::Union{Int32,Nothing}=newinst.line,
    flag::Union{UInt8,Nothing}=newinst.flag)
    return NewInstruction(stmt, type, info, line, flag)
end
@Specialize

using BenchmarkTools
struct VirtualKwargs
    stmt::Any
    type::Any
    info::CallInfo
end
vkws = VirtualKwargs(nothing, Any, NoCallInfo())
newinst = NewInstruction(nothing, Any, NoCallInfo(), nothing, nothing)
runner(newinst, vkws) = NewInstruction(newinst; vkws.stmt, vkws.type, vkws.info)
@benchmark runner($newinst, $vkws)
```

> on master
```
BenchmarkTools.Trial: 10000 samples with 186 evaluations.
 Range (min … max):  559.898 ns …   4.173 μs  ┊ GC (min … max): 0.00% … 85.29%
 Time  (median):     605.608 ns               ┊ GC (median):    0.00%
 Time  (mean ± σ):   638.170 ns ± 125.080 ns  ┊ GC (mean ± σ):  0.06% ±  0.85%

  █▇▂▆▄  ▁█▇▄▂                                                  ▂
  ██████▅██████▇▇▇██████▇▇▇▆▆▅▄▅▄▂▄▄▅▇▆▆▆▆▆▅▆▆▄▄▅▅▄▃▄▄▄▅▃▅▅▆▅▆▆ █
  560 ns        Histogram: log(frequency) by time       1.23 μs <

 Memory estimate: 32 bytes, allocs estimate: 2.
```

> on this commit
```julia
BenchmarkTools.Trial: 10000 samples with 1000 evaluations.
 Range (min … max):  3.080 ns … 83.177 ns  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     3.098 ns              ┊ GC (median):    0.00%
 Time  (mean ± σ):   3.118 ns ±  0.885 ns  ┊ GC (mean ± σ):  0.00% ± 0.00%

       ▂▅▇█▆▅▄▂
  ▂▄▆▆▇████████▆▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁▁▂▂▂▁▂▂▂▂▂▂▁▁▂▁▂▂▂▂▂▂▂▂▂ ▃
  3.08 ns        Histogram: frequency by time        3.19 ns <

 Memory estimate: 0 bytes, allocs estimate: 0.
```

So for this particular case it achieves roughly 200x speed up.
This is because this commit allows inlining of a call to keyword sorter
as well as removal of `NamedTuple` call.

Especially this commit is composed of the following improvements:
- add early return case for `structdiff`:
  This change improves the return type inference for a case when
  compared `NamedTuple`s are type unstable but there is no difference
  in their names, e.g. given two `NamedTuple{(:a,:b),T} where T<:Tuple{Any,Any}`s.
  And in such case the optimizer will remove `structdiff` and succeeding
  `pairs` calls, letting the keyword sorter to be inlined.
- add special SROA handling for `NamedTuple` generated by keyword sorter:
  With the change on `structdiff`, IR for a call with type-unstable
  keyword arguments after inlining would look like:
  ```
  %1 = tuple(a, b, c)::Tuple{Any, Any, Any}
  %2 = NamedTuple{(:a, :b, :c)(%1)::NamedTuple{(:a, :b, :c), _A} where _A<:Tuple{Any, Any, Any}
  %3  = Core.getfield(%2, :a)::Any
  %4  = Core.getfield(%2, :b)::Any
  %5  = Core.getfield(%2, :c)::Any
  [... other body of the keyword func ...]
  ```
  We can implement a bit hacky special handling within our SROA pass
  that checks if this definition (%2) is partly well-known `NamedTuple`
  construction, where its names are fully known, and also checks if its
  call argument (%1) is fully-known `tuple` call. In a case when the
  length of the `NamedTuple` names and the length of the arguments for
  the `tuple` call, we can safely replace those `getfield` calls with
  the corresponding `tuple` call argument, while letting the later DCE
  pass to delete the constructions of tuple and named-tuple altogether.

With these changes, the IR for the example `NewInstruction` constructor
is fairly optimized, like:
```julia
julia> Base.code_ircode((NewInstruction,Any,Any,CallInfo)) do newinst, stmt, type, info
           NewInstruction(newinst; stmt, type, info)
       end |> only
2 1 ── %1  = Base.getfield(_2, :line)::Union{Nothing, Int32}                    │╻╷  Type##kw
  │    %2  = Base.getfield(_2, :flag)::Union{Nothing, UInt8}                    ││┃   getproperty
  │    %3  = (isa)(%1, Nothing)::Bool                                           ││
  │    %4  = (isa)(%2, Nothing)::Bool                                           ││
  │    %5  = (Core.Intrinsics.and_int)(%3, %4)::Bool                            ││
  └───       goto #3 if not %5                                                  ││
  2 ── %7  = %new(Main.NewInstruction, _3, _4, _5, nothing, nothing)::NewInstruction   NewInstruction
  └───       goto #10                                                           ││
  3 ── %9  = (isa)(%1, Int32)::Bool                                             ││
  │    %10 = (isa)(%2, Nothing)::Bool                                           ││
  │    %11 = (Core.Intrinsics.and_int)(%9, %10)::Bool                           ││
  └───       goto #5 if not %11                                                 ││
  4 ── %13 = π (%1, Int32)                                                      ││
  │    %14 = %new(Main.NewInstruction, _3, _4, _5, %13, nothing)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  5 ── %16 = (isa)(%1, Nothing)::Bool                                           ││
  │    %17 = (isa)(%2, UInt8)::Bool                                             ││
  │    %18 = (Core.Intrinsics.and_int)(%16, %17)::Bool                          ││
  └───       goto #7 if not %18                                                 ││
  6 ── %20 = π (%2, UInt8)                                                      ││
  │    %21 = %new(Main.NewInstruction, _3, _4, _5, nothing, %20)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  7 ── %23 = (isa)(%1, Int32)::Bool                                             ││
  │    %24 = (isa)(%2, UInt8)::Bool                                             ││
  │    %25 = (Core.Intrinsics.and_int)(%23, %24)::Bool                          ││
  └───       goto #9 if not %25                                                 ││
  8 ── %27 = π (%1, Int32)                                                      ││
  │    %28 = π (%2, UInt8)                                                      ││
  │    %29 = %new(Main.NewInstruction, _3, _4, _5, %27, %28)::NewInstruction    │││╻   NewInstruction
  └───       goto #10                                                           ││
  9 ──       Core.throw(ErrorException("fatal error in type inference (type bound)"))::Union{}
  └───       unreachable                                                        ││
  10 ┄ %33 = φ (#2 => %7, #4 => %14, #6 => %21, #8 => %29)::NewInstruction      ││
  └───       goto #11                                                           ││
  11 ─       return %33                                                         │
   => NewInstruction
```
aviatesk added a commit that referenced this issue Oct 8, 2022
This commit tries to fix and improve performance for calling keyword
funcs whose arguments types are not fully known but `@nospecialize`-d.

The final result would look like (this particular example is taken from
our Julia-level compiler implementation):
```julia
abstract type CallInfo end
struct NoCallInfo <: CallInfo end
struct NewInstruction
    stmt::Any
    type::Any
    info::CallInfo
    line::Union{Int32,Nothing} # if nothing, copy the line from previous statement in the insertion location
    flag::Union{UInt8,Nothing} # if nothing, IR flags will be recomputed on insertion
    function NewInstruction(@nospecialize(stmt), @nospecialize(type), @nospecialize(info::CallInfo),
                            line::Union{Int32,Nothing}, flag::Union{UInt8,Nothing})
        return new(stmt, type, info, line, flag)
    end
end
@nospecialize
function NewInstruction(newinst::NewInstruction;
    stmt=newinst.stmt,
    type=newinst.type,
    info::CallInfo=newinst.info,
    line::Union{Int32,Nothing}=newinst.line,
    flag::Union{UInt8,Nothing}=newinst.flag)
    return NewInstruction(stmt, type, info, line, flag)
end
@Specialize

using BenchmarkTools
struct VirtualKwargs
    stmt::Any
    type::Any
    info::CallInfo
end
vkws = VirtualKwargs(nothing, Any, NoCallInfo())
newinst = NewInstruction(nothing, Any, NoCallInfo(), nothing, nothing)
runner(newinst, vkws) = NewInstruction(newinst; vkws.stmt, vkws.type, vkws.info)
@benchmark runner($newinst, $vkws)
```

> on master
```
BenchmarkTools.Trial: 10000 samples with 186 evaluations.
 Range (min … max):  559.898 ns …   4.173 μs  ┊ GC (min … max): 0.00% … 85.29%
 Time  (median):     605.608 ns               ┊ GC (median):    0.00%
 Time  (mean ± σ):   638.170 ns ± 125.080 ns  ┊ GC (mean ± σ):  0.06% ±  0.85%

  █▇▂▆▄  ▁█▇▄▂                                                  ▂
  ██████▅██████▇▇▇██████▇▇▇▆▆▅▄▅▄▂▄▄▅▇▆▆▆▆▆▅▆▆▄▄▅▅▄▃▄▄▄▅▃▅▅▆▅▆▆ █
  560 ns        Histogram: log(frequency) by time       1.23 μs <

 Memory estimate: 32 bytes, allocs estimate: 2.
```

> on this commit
```julia
BenchmarkTools.Trial: 10000 samples with 1000 evaluations.
 Range (min … max):  3.080 ns … 83.177 ns  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     3.098 ns              ┊ GC (median):    0.00%
 Time  (mean ± σ):   3.118 ns ±  0.885 ns  ┊ GC (mean ± σ):  0.00% ± 0.00%

       ▂▅▇█▆▅▄▂
  ▂▄▆▆▇████████▆▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁▁▂▂▂▁▂▂▂▂▂▂▁▁▂▁▂▂▂▂▂▂▂▂▂ ▃
  3.08 ns        Histogram: frequency by time        3.19 ns <

 Memory estimate: 0 bytes, allocs estimate: 0.
```

So for this particular case it achieves roughly 200x speed up.
This is because this commit allows inlining of a call to keyword sorter
as well as removal of `NamedTuple` call.

Especially this commit is composed of the following improvements:
- Add early return case for `structdiff`:
  This change improves the return type inference for a case when
  compared `NamedTuple`s are type unstable but there is no difference
  in their names, e.g. given two `NamedTuple{(:a,:b),T} where T<:Tuple{Any,Any}`s.
  And in such case the optimizer will remove `structdiff` and succeeding
  `pairs` calls, letting the keyword sorter to be inlined.
- Tweak the core `NamedTuple{names}(args::Tuple)` constructor so that it
  directly forms `:splatnew` allocation rather than redirects to the
  general `NamedTuple` constructor, that could be confused for abstract
  input tuple type.
- Improve `nfields_tfunc` accuracy as for abstract `NamedTuple` types.
  This improvement lets `inline_splatnew` to handle more abstract
  `NamedTuple`s, especially whose names are fully known but its fields
  tuple type is abstract.

Those improvements are combined to allow our SROA pass to optimize away
`NamedTuple` and `tuple` calls generated for keyword argument handling.
E.g. the IR for the example `NewInstruction` constructor is now fairly
optimized, like:
```julia
julia> Base.code_ircode((NewInstruction,Any,Any,CallInfo)) do newinst, stmt, type, info
           NewInstruction(newinst; stmt, type, info)
       end |> only
2 1 ── %1  = Base.getfield(_2, :line)::Union{Nothing, Int32}                    │╻╷  Type##kw
  │    %2  = Base.getfield(_2, :flag)::Union{Nothing, UInt8}                    ││┃   getproperty
  │    %3  = (isa)(%1, Nothing)::Bool                                           ││
  │    %4  = (isa)(%2, Nothing)::Bool                                           ││
  │    %5  = (Core.Intrinsics.and_int)(%3, %4)::Bool                            ││
  └───       goto #3 if not %5                                                  ││
  2 ── %7  = %new(Main.NewInstruction, _3, _4, _5, nothing, nothing)::NewInstruction   NewInstruction
  └───       goto #10                                                           ││
  3 ── %9  = (isa)(%1, Int32)::Bool                                             ││
  │    %10 = (isa)(%2, Nothing)::Bool                                           ││
  │    %11 = (Core.Intrinsics.and_int)(%9, %10)::Bool                           ││
  └───       goto #5 if not %11                                                 ││
  4 ── %13 = π (%1, Int32)                                                      ││
  │    %14 = %new(Main.NewInstruction, _3, _4, _5, %13, nothing)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  5 ── %16 = (isa)(%1, Nothing)::Bool                                           ││
  │    %17 = (isa)(%2, UInt8)::Bool                                             ││
  │    %18 = (Core.Intrinsics.and_int)(%16, %17)::Bool                          ││
  └───       goto #7 if not %18                                                 ││
  6 ── %20 = π (%2, UInt8)                                                      ││
  │    %21 = %new(Main.NewInstruction, _3, _4, _5, nothing, %20)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  7 ── %23 = (isa)(%1, Int32)::Bool                                             ││
  │    %24 = (isa)(%2, UInt8)::Bool                                             ││
  │    %25 = (Core.Intrinsics.and_int)(%23, %24)::Bool                          ││
  └───       goto #9 if not %25                                                 ││
  8 ── %27 = π (%1, Int32)                                                      ││
  │    %28 = π (%2, UInt8)                                                      ││
  │    %29 = %new(Main.NewInstruction, _3, _4, _5, %27, %28)::NewInstruction    │││╻   NewInstruction
  └───       goto #10                                                           ││
  9 ──       Core.throw(ErrorException("fatal error in type inference (type bound)"))::Union{}
  └───       unreachable                                                        ││
  10 ┄ %33 = φ (#2 => %7, #4 => %14, #6 => %21, #8 => %29)::NewInstruction      ││
  └───       goto #11                                                           ││
  11 ─       return %33                                                         │
   => NewInstruction
```
aviatesk added a commit that referenced this issue Oct 8, 2022
This commit tries to fix and improve performance for calling keyword
funcs whose arguments types are not fully known but `@nospecialize`-d.

The final result would look like (this particular example is taken from
our Julia-level compiler implementation):
```julia
abstract type CallInfo end
struct NoCallInfo <: CallInfo end
struct NewInstruction
    stmt::Any
    type::Any
    info::CallInfo
    line::Union{Int32,Nothing} # if nothing, copy the line from previous statement in the insertion location
    flag::Union{UInt8,Nothing} # if nothing, IR flags will be recomputed on insertion
    function NewInstruction(@nospecialize(stmt), @nospecialize(type), @nospecialize(info::CallInfo),
                            line::Union{Int32,Nothing}, flag::Union{UInt8,Nothing})
        return new(stmt, type, info, line, flag)
    end
end
@nospecialize
function NewInstruction(newinst::NewInstruction;
    stmt=newinst.stmt,
    type=newinst.type,
    info::CallInfo=newinst.info,
    line::Union{Int32,Nothing}=newinst.line,
    flag::Union{UInt8,Nothing}=newinst.flag)
    return NewInstruction(stmt, type, info, line, flag)
end
@Specialize

using BenchmarkTools
struct VirtualKwargs
    stmt::Any
    type::Any
    info::CallInfo
end
vkws = VirtualKwargs(nothing, Any, NoCallInfo())
newinst = NewInstruction(nothing, Any, NoCallInfo(), nothing, nothing)
runner(newinst, vkws) = NewInstruction(newinst; vkws.stmt, vkws.type, vkws.info)
@benchmark runner($newinst, $vkws)
```

> on master
```
BenchmarkTools.Trial: 10000 samples with 186 evaluations.
 Range (min … max):  559.898 ns …   4.173 μs  ┊ GC (min … max): 0.00% … 85.29%
 Time  (median):     605.608 ns               ┊ GC (median):    0.00%
 Time  (mean ± σ):   638.170 ns ± 125.080 ns  ┊ GC (mean ± σ):  0.06% ±  0.85%

  █▇▂▆▄  ▁█▇▄▂                                                  ▂
  ██████▅██████▇▇▇██████▇▇▇▆▆▅▄▅▄▂▄▄▅▇▆▆▆▆▆▅▆▆▄▄▅▅▄▃▄▄▄▅▃▅▅▆▅▆▆ █
  560 ns        Histogram: log(frequency) by time       1.23 μs <

 Memory estimate: 32 bytes, allocs estimate: 2.
```

> on this commit
```julia
BenchmarkTools.Trial: 10000 samples with 1000 evaluations.
 Range (min … max):  3.080 ns … 83.177 ns  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     3.098 ns              ┊ GC (median):    0.00%
 Time  (mean ± σ):   3.118 ns ±  0.885 ns  ┊ GC (mean ± σ):  0.00% ± 0.00%

       ▂▅▇█▆▅▄▂
  ▂▄▆▆▇████████▆▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁▁▂▂▂▁▂▂▂▂▂▂▁▁▂▁▂▂▂▂▂▂▂▂▂ ▃
  3.08 ns        Histogram: frequency by time        3.19 ns <

 Memory estimate: 0 bytes, allocs estimate: 0.
```

So for this particular case it achieves roughly 200x speed up.
This is because this commit allows inlining of a call to keyword sorter
as well as removal of `NamedTuple` call.

Especially this commit is composed of the following improvements:
- Add early return case for `structdiff`:
  This change improves the return type inference for a case when
  compared `NamedTuple`s are type unstable but there is no difference
  in their names, e.g. given two `NamedTuple{(:a,:b),T} where T<:Tuple{Any,Any}`s.
  And in such case the optimizer will remove `structdiff` and succeeding
  `pairs` calls, letting the keyword sorter to be inlined.
- Tweak the core `NamedTuple{names}(args::Tuple)` constructor so that it
  directly forms `:splatnew` allocation rather than redirects to the
  general `NamedTuple` constructor, that could be confused for abstract
  input tuple type.
- Improve `nfields_tfunc` accuracy as for abstract `NamedTuple` types.
  This improvement lets `inline_splatnew` to handle more abstract
  `NamedTuple`s, especially whose names are fully known but its fields
  tuple type is abstract.

Those improvements are combined to allow our SROA pass to optimize away
`NamedTuple` and `tuple` calls generated for keyword argument handling.
E.g. the IR for the example `NewInstruction` constructor is now fairly
optimized, like:
```julia
julia> Base.code_ircode((NewInstruction,Any,Any,CallInfo)) do newinst, stmt, type, info
           NewInstruction(newinst; stmt, type, info)
       end |> only
2 1 ── %1  = Base.getfield(_2, :line)::Union{Nothing, Int32}                    │╻╷  Type##kw
  │    %2  = Base.getfield(_2, :flag)::Union{Nothing, UInt8}                    ││┃   getproperty
  │    %3  = (isa)(%1, Nothing)::Bool                                           ││
  │    %4  = (isa)(%2, Nothing)::Bool                                           ││
  │    %5  = (Core.Intrinsics.and_int)(%3, %4)::Bool                            ││
  └───       goto #3 if not %5                                                  ││
  2 ── %7  = %new(Main.NewInstruction, _3, _4, _5, nothing, nothing)::NewInstruction   NewInstruction
  └───       goto #10                                                           ││
  3 ── %9  = (isa)(%1, Int32)::Bool                                             ││
  │    %10 = (isa)(%2, Nothing)::Bool                                           ││
  │    %11 = (Core.Intrinsics.and_int)(%9, %10)::Bool                           ││
  └───       goto #5 if not %11                                                 ││
  4 ── %13 = π (%1, Int32)                                                      ││
  │    %14 = %new(Main.NewInstruction, _3, _4, _5, %13, nothing)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  5 ── %16 = (isa)(%1, Nothing)::Bool                                           ││
  │    %17 = (isa)(%2, UInt8)::Bool                                             ││
  │    %18 = (Core.Intrinsics.and_int)(%16, %17)::Bool                          ││
  └───       goto #7 if not %18                                                 ││
  6 ── %20 = π (%2, UInt8)                                                      ││
  │    %21 = %new(Main.NewInstruction, _3, _4, _5, nothing, %20)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  7 ── %23 = (isa)(%1, Int32)::Bool                                             ││
  │    %24 = (isa)(%2, UInt8)::Bool                                             ││
  │    %25 = (Core.Intrinsics.and_int)(%23, %24)::Bool                          ││
  └───       goto #9 if not %25                                                 ││
  8 ── %27 = π (%1, Int32)                                                      ││
  │    %28 = π (%2, UInt8)                                                      ││
  │    %29 = %new(Main.NewInstruction, _3, _4, _5, %27, %28)::NewInstruction    │││╻   NewInstruction
  └───       goto #10                                                           ││
  9 ──       Core.throw(ErrorException("fatal error in type inference (type bound)"))::Union{}
  └───       unreachable                                                        ││
  10 ┄ %33 = φ (#2 => %7, #4 => %14, #6 => %21, #8 => %29)::NewInstruction      ││
  └───       goto #11                                                           ││
  11 ─       return %33                                                         │
   => NewInstruction
```
aviatesk added a commit that referenced this issue Oct 8, 2022
This commit tries to fix and improve performance for calling keyword
funcs whose arguments types are not fully known but `@nospecialize`-d.

The final result would look like (this particular example is taken from
our Julia-level compiler implementation):
```julia
abstract type CallInfo end
struct NoCallInfo <: CallInfo end
struct NewInstruction
    stmt::Any
    type::Any
    info::CallInfo
    line::Union{Int32,Nothing} # if nothing, copy the line from previous statement in the insertion location
    flag::Union{UInt8,Nothing} # if nothing, IR flags will be recomputed on insertion
    function NewInstruction(@nospecialize(stmt), @nospecialize(type), @nospecialize(info::CallInfo),
                            line::Union{Int32,Nothing}, flag::Union{UInt8,Nothing})
        return new(stmt, type, info, line, flag)
    end
end
@nospecialize
function NewInstruction(newinst::NewInstruction;
    stmt=newinst.stmt,
    type=newinst.type,
    info::CallInfo=newinst.info,
    line::Union{Int32,Nothing}=newinst.line,
    flag::Union{UInt8,Nothing}=newinst.flag)
    return NewInstruction(stmt, type, info, line, flag)
end
@Specialize

using BenchmarkTools
struct VirtualKwargs
    stmt::Any
    type::Any
    info::CallInfo
end
vkws = VirtualKwargs(nothing, Any, NoCallInfo())
newinst = NewInstruction(nothing, Any, NoCallInfo(), nothing, nothing)
runner(newinst, vkws) = NewInstruction(newinst; vkws.stmt, vkws.type, vkws.info)
@benchmark runner($newinst, $vkws)
```

> on master
```
BenchmarkTools.Trial: 10000 samples with 186 evaluations.
 Range (min … max):  559.898 ns …   4.173 μs  ┊ GC (min … max): 0.00% … 85.29%
 Time  (median):     605.608 ns               ┊ GC (median):    0.00%
 Time  (mean ± σ):   638.170 ns ± 125.080 ns  ┊ GC (mean ± σ):  0.06% ±  0.85%

  █▇▂▆▄  ▁█▇▄▂                                                  ▂
  ██████▅██████▇▇▇██████▇▇▇▆▆▅▄▅▄▂▄▄▅▇▆▆▆▆▆▅▆▆▄▄▅▅▄▃▄▄▄▅▃▅▅▆▅▆▆ █
  560 ns        Histogram: log(frequency) by time       1.23 μs <

 Memory estimate: 32 bytes, allocs estimate: 2.
```

> on this commit
```julia
BenchmarkTools.Trial: 10000 samples with 1000 evaluations.
 Range (min … max):  3.080 ns … 83.177 ns  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     3.098 ns              ┊ GC (median):    0.00%
 Time  (mean ± σ):   3.118 ns ±  0.885 ns  ┊ GC (mean ± σ):  0.00% ± 0.00%

       ▂▅▇█▆▅▄▂
  ▂▄▆▆▇████████▆▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁▁▂▂▂▁▂▂▂▂▂▂▁▁▂▁▂▂▂▂▂▂▂▂▂ ▃
  3.08 ns        Histogram: frequency by time        3.19 ns <

 Memory estimate: 0 bytes, allocs estimate: 0.
```

So for this particular case it achieves roughly 200x speed up.
This is because this commit allows inlining of a call to keyword sorter
as well as removal of `NamedTuple` call.

Especially this commit is composed of the following improvements:
- Add early return case for `structdiff`:
  This change improves the return type inference for a case when
  compared `NamedTuple`s are type unstable but there is no difference
  in their names, e.g. given two `NamedTuple{(:a,:b),T} where T<:Tuple{Any,Any}`s.
  And in such case the optimizer will remove `structdiff` and succeeding
  `pairs` calls, letting the keyword sorter to be inlined.
- Tweak the core `NamedTuple{names}(args::Tuple)` constructor so that it
  directly forms `:splatnew` allocation rather than redirects to the
  general `NamedTuple` constructor, that could be confused for abstract
  input tuple type.
- Improve `nfields_tfunc` accuracy as for abstract `NamedTuple` types.
  This improvement lets `inline_splatnew` to handle more abstract
  `NamedTuple`s, especially whose names are fully known but its fields
  tuple type is abstract.

Those improvements are combined to allow our SROA pass to optimize away
`NamedTuple` and `tuple` calls generated for keyword argument handling.
E.g. the IR for the example `NewInstruction` constructor is now fairly
optimized, like:
```julia
julia> Base.code_ircode((NewInstruction,Any,Any,CallInfo)) do newinst, stmt, type, info
           NewInstruction(newinst; stmt, type, info)
       end |> only
2 1 ── %1  = Base.getfield(_2, :line)::Union{Nothing, Int32}                    │╻╷  Type##kw
  │    %2  = Base.getfield(_2, :flag)::Union{Nothing, UInt8}                    ││┃   getproperty
  │    %3  = (isa)(%1, Nothing)::Bool                                           ││
  │    %4  = (isa)(%2, Nothing)::Bool                                           ││
  │    %5  = (Core.Intrinsics.and_int)(%3, %4)::Bool                            ││
  └───       goto #3 if not %5                                                  ││
  2 ── %7  = %new(Main.NewInstruction, _3, _4, _5, nothing, nothing)::NewInstruction   NewInstruction
  └───       goto #10                                                           ││
  3 ── %9  = (isa)(%1, Int32)::Bool                                             ││
  │    %10 = (isa)(%2, Nothing)::Bool                                           ││
  │    %11 = (Core.Intrinsics.and_int)(%9, %10)::Bool                           ││
  └───       goto #5 if not %11                                                 ││
  4 ── %13 = π (%1, Int32)                                                      ││
  │    %14 = %new(Main.NewInstruction, _3, _4, _5, %13, nothing)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  5 ── %16 = (isa)(%1, Nothing)::Bool                                           ││
  │    %17 = (isa)(%2, UInt8)::Bool                                             ││
  │    %18 = (Core.Intrinsics.and_int)(%16, %17)::Bool                          ││
  └───       goto #7 if not %18                                                 ││
  6 ── %20 = π (%2, UInt8)                                                      ││
  │    %21 = %new(Main.NewInstruction, _3, _4, _5, nothing, %20)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  7 ── %23 = (isa)(%1, Int32)::Bool                                             ││
  │    %24 = (isa)(%2, UInt8)::Bool                                             ││
  │    %25 = (Core.Intrinsics.and_int)(%23, %24)::Bool                          ││
  └───       goto #9 if not %25                                                 ││
  8 ── %27 = π (%1, Int32)                                                      ││
  │    %28 = π (%2, UInt8)                                                      ││
  │    %29 = %new(Main.NewInstruction, _3, _4, _5, %27, %28)::NewInstruction    │││╻   NewInstruction
  └───       goto #10                                                           ││
  9 ──       Core.throw(ErrorException("fatal error in type inference (type bound)"))::Union{}
  └───       unreachable                                                        ││
  10 ┄ %33 = φ (#2 => %7, #4 => %14, #6 => %21, #8 => %29)::NewInstruction      ││
  └───       goto #11                                                           ││
  11 ─       return %33                                                         │
   => NewInstruction
```
aviatesk added a commit that referenced this issue Oct 8, 2022
This commit tries to fix and improve performance for calling keyword
funcs whose arguments types are not fully known but `@nospecialize`-d.

The final result would look like (this particular example is taken from
our Julia-level compiler implementation):
```julia
abstract type CallInfo end
struct NoCallInfo <: CallInfo end
struct NewInstruction
    stmt::Any
    type::Any
    info::CallInfo
    line::Union{Int32,Nothing} # if nothing, copy the line from previous statement in the insertion location
    flag::Union{UInt8,Nothing} # if nothing, IR flags will be recomputed on insertion
    function NewInstruction(@nospecialize(stmt), @nospecialize(type), @nospecialize(info::CallInfo),
                            line::Union{Int32,Nothing}, flag::Union{UInt8,Nothing})
        return new(stmt, type, info, line, flag)
    end
end
@nospecialize
function NewInstruction(newinst::NewInstruction;
    stmt=newinst.stmt,
    type=newinst.type,
    info::CallInfo=newinst.info,
    line::Union{Int32,Nothing}=newinst.line,
    flag::Union{UInt8,Nothing}=newinst.flag)
    return NewInstruction(stmt, type, info, line, flag)
end
@Specialize

using BenchmarkTools
struct VirtualKwargs
    stmt::Any
    type::Any
    info::CallInfo
end
vkws = VirtualKwargs(nothing, Any, NoCallInfo())
newinst = NewInstruction(nothing, Any, NoCallInfo(), nothing, nothing)
runner(newinst, vkws) = NewInstruction(newinst; vkws.stmt, vkws.type, vkws.info)
@benchmark runner($newinst, $vkws)
```

> on master
```
BenchmarkTools.Trial: 10000 samples with 186 evaluations.
 Range (min … max):  559.898 ns …   4.173 μs  ┊ GC (min … max): 0.00% … 85.29%
 Time  (median):     605.608 ns               ┊ GC (median):    0.00%
 Time  (mean ± σ):   638.170 ns ± 125.080 ns  ┊ GC (mean ± σ):  0.06% ±  0.85%

  █▇▂▆▄  ▁█▇▄▂                                                  ▂
  ██████▅██████▇▇▇██████▇▇▇▆▆▅▄▅▄▂▄▄▅▇▆▆▆▆▆▅▆▆▄▄▅▅▄▃▄▄▄▅▃▅▅▆▅▆▆ █
  560 ns        Histogram: log(frequency) by time       1.23 μs <

 Memory estimate: 32 bytes, allocs estimate: 2.
```

> on this commit
```julia
BenchmarkTools.Trial: 10000 samples with 1000 evaluations.
 Range (min … max):  3.080 ns … 83.177 ns  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     3.098 ns              ┊ GC (median):    0.00%
 Time  (mean ± σ):   3.118 ns ±  0.885 ns  ┊ GC (mean ± σ):  0.00% ± 0.00%

       ▂▅▇█▆▅▄▂
  ▂▄▆▆▇████████▆▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁▁▂▂▂▁▂▂▂▂▂▂▁▁▂▁▂▂▂▂▂▂▂▂▂ ▃
  3.08 ns        Histogram: frequency by time        3.19 ns <

 Memory estimate: 0 bytes, allocs estimate: 0.
```

So for this particular case it achieves roughly 200x speed up.
This is because this commit allows inlining of a call to keyword sorter
as well as removal of `NamedTuple` call.

Especially this commit is composed of the following improvements:
- Add early return case for `structdiff`:
  This change improves the return type inference for a case when
  compared `NamedTuple`s are type unstable but there is no difference
  in their names, e.g. given two `NamedTuple{(:a,:b),T} where T<:Tuple{Any,Any}`s.
  And in such case the optimizer will remove `structdiff` and succeeding
  `pairs` calls, letting the keyword sorter to be inlined.
- Tweak the core `NamedTuple{names}(args::Tuple)` constructor so that it
  directly forms `:splatnew` allocation rather than redirects to the
  general `NamedTuple` constructor, that could be confused for abstract
  input tuple type.
- Improve `nfields_tfunc` accuracy as for abstract `NamedTuple` types.
  This improvement lets `inline_splatnew` to handle more abstract
  `NamedTuple`s, especially whose names are fully known but its fields
  tuple type is abstract.

Those improvements are combined to allow our SROA pass to optimize away
`NamedTuple` and `tuple` calls generated for keyword argument handling.
E.g. the IR for the example `NewInstruction` constructor is now fairly
optimized, like:
```julia
julia> Base.code_ircode((NewInstruction,Any,Any,CallInfo)) do newinst, stmt, type, info
           NewInstruction(newinst; stmt, type, info)
       end |> only
2 1 ── %1  = Base.getfield(_2, :line)::Union{Nothing, Int32}                    │╻╷  Type##kw
  │    %2  = Base.getfield(_2, :flag)::Union{Nothing, UInt8}                    ││┃   getproperty
  │    %3  = (isa)(%1, Nothing)::Bool                                           ││
  │    %4  = (isa)(%2, Nothing)::Bool                                           ││
  │    %5  = (Core.Intrinsics.and_int)(%3, %4)::Bool                            ││
  └───       goto #3 if not %5                                                  ││
  2 ── %7  = %new(Main.NewInstruction, _3, _4, _5, nothing, nothing)::NewInstruction   NewInstruction
  └───       goto #10                                                           ││
  3 ── %9  = (isa)(%1, Int32)::Bool                                             ││
  │    %10 = (isa)(%2, Nothing)::Bool                                           ││
  │    %11 = (Core.Intrinsics.and_int)(%9, %10)::Bool                           ││
  └───       goto #5 if not %11                                                 ││
  4 ── %13 = π (%1, Int32)                                                      ││
  │    %14 = %new(Main.NewInstruction, _3, _4, _5, %13, nothing)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  5 ── %16 = (isa)(%1, Nothing)::Bool                                           ││
  │    %17 = (isa)(%2, UInt8)::Bool                                             ││
  │    %18 = (Core.Intrinsics.and_int)(%16, %17)::Bool                          ││
  └───       goto #7 if not %18                                                 ││
  6 ── %20 = π (%2, UInt8)                                                      ││
  │    %21 = %new(Main.NewInstruction, _3, _4, _5, nothing, %20)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  7 ── %23 = (isa)(%1, Int32)::Bool                                             ││
  │    %24 = (isa)(%2, UInt8)::Bool                                             ││
  │    %25 = (Core.Intrinsics.and_int)(%23, %24)::Bool                          ││
  └───       goto #9 if not %25                                                 ││
  8 ── %27 = π (%1, Int32)                                                      ││
  │    %28 = π (%2, UInt8)                                                      ││
  │    %29 = %new(Main.NewInstruction, _3, _4, _5, %27, %28)::NewInstruction    │││╻   NewInstruction
  └───       goto #10                                                           ││
  9 ──       Core.throw(ErrorException("fatal error in type inference (type bound)"))::Union{}
  └───       unreachable                                                        ││
  10 ┄ %33 = φ (#2 => %7, #4 => %14, #6 => %21, #8 => %29)::NewInstruction      ││
  └───       goto #11                                                           ││
  11 ─       return %33                                                         │
   => NewInstruction
```
aviatesk added a commit that referenced this issue Oct 8, 2022
This commit tries to fix and improve performance for calling keyword
funcs whose arguments types are not fully known but `@nospecialize`-d.

The final result would look like (this particular example is taken from
our Julia-level compiler implementation):
```julia
abstract type CallInfo end
struct NoCallInfo <: CallInfo end
struct NewInstruction
    stmt::Any
    type::Any
    info::CallInfo
    line::Union{Int32,Nothing} # if nothing, copy the line from previous statement in the insertion location
    flag::Union{UInt8,Nothing} # if nothing, IR flags will be recomputed on insertion
    function NewInstruction(@nospecialize(stmt), @nospecialize(type), @nospecialize(info::CallInfo),
                            line::Union{Int32,Nothing}, flag::Union{UInt8,Nothing})
        return new(stmt, type, info, line, flag)
    end
end
@nospecialize
function NewInstruction(newinst::NewInstruction;
    stmt=newinst.stmt,
    type=newinst.type,
    info::CallInfo=newinst.info,
    line::Union{Int32,Nothing}=newinst.line,
    flag::Union{UInt8,Nothing}=newinst.flag)
    return NewInstruction(stmt, type, info, line, flag)
end
@Specialize

using BenchmarkTools
struct VirtualKwargs
    stmt::Any
    type::Any
    info::CallInfo
end
vkws = VirtualKwargs(nothing, Any, NoCallInfo())
newinst = NewInstruction(nothing, Any, NoCallInfo(), nothing, nothing)
runner(newinst, vkws) = NewInstruction(newinst; vkws.stmt, vkws.type, vkws.info)
@benchmark runner($newinst, $vkws)
```

> on master
```
BenchmarkTools.Trial: 10000 samples with 186 evaluations.
 Range (min … max):  559.898 ns …   4.173 μs  ┊ GC (min … max): 0.00% … 85.29%
 Time  (median):     605.608 ns               ┊ GC (median):    0.00%
 Time  (mean ± σ):   638.170 ns ± 125.080 ns  ┊ GC (mean ± σ):  0.06% ±  0.85%

  █▇▂▆▄  ▁█▇▄▂                                                  ▂
  ██████▅██████▇▇▇██████▇▇▇▆▆▅▄▅▄▂▄▄▅▇▆▆▆▆▆▅▆▆▄▄▅▅▄▃▄▄▄▅▃▅▅▆▅▆▆ █
  560 ns        Histogram: log(frequency) by time       1.23 μs <

 Memory estimate: 32 bytes, allocs estimate: 2.
```

> on this commit
```julia
BenchmarkTools.Trial: 10000 samples with 1000 evaluations.
 Range (min … max):  3.080 ns … 83.177 ns  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     3.098 ns              ┊ GC (median):    0.00%
 Time  (mean ± σ):   3.118 ns ±  0.885 ns  ┊ GC (mean ± σ):  0.00% ± 0.00%

       ▂▅▇█▆▅▄▂
  ▂▄▆▆▇████████▆▃▃▃▃▃▃▃▃▃▃▂▂▂▂▂▂▂▂▂▁▁▂▂▂▁▂▂▂▂▂▂▁▁▂▁▂▂▂▂▂▂▂▂▂ ▃
  3.08 ns        Histogram: frequency by time        3.19 ns <

 Memory estimate: 0 bytes, allocs estimate: 0.
```

So for this particular case it achieves roughly 200x speed up.
This is because this commit allows inlining of a call to keyword sorter
as well as removal of `NamedTuple` call.

Especially this commit is composed of the following improvements:
- Add early return case for `structdiff`:
  This change improves the return type inference for a case when
  compared `NamedTuple`s are type unstable but there is no difference
  in their names, e.g. given two `NamedTuple{(:a,:b),T} where T<:Tuple{Any,Any}`s.
  And in such case the optimizer will remove `structdiff` and succeeding
  `pairs` calls, letting the keyword sorter to be inlined.
- Tweak the core `NamedTuple{names}(args::Tuple)` constructor so that it
  directly forms `:splatnew` allocation rather than redirects to the
  general `NamedTuple` constructor, that could be confused for abstract
  input tuple type.
- Improve `nfields_tfunc` accuracy as for abstract `NamedTuple` types.
  This improvement lets `inline_splatnew` to handle more abstract
  `NamedTuple`s, especially whose names are fully known but its fields
  tuple type is abstract.

Those improvements are combined to allow our SROA pass to optimize away
`NamedTuple` and `tuple` calls generated for keyword argument handling.
E.g. the IR for the example `NewInstruction` constructor is now fairly
optimized, like:
```julia
julia> Base.code_ircode((NewInstruction,Any,Any,CallInfo)) do newinst, stmt, type, info
           NewInstruction(newinst; stmt, type, info)
       end |> only
2 1 ── %1  = Base.getfield(_2, :line)::Union{Nothing, Int32}                    │╻╷  Type##kw
  │    %2  = Base.getfield(_2, :flag)::Union{Nothing, UInt8}                    ││┃   getproperty
  │    %3  = (isa)(%1, Nothing)::Bool                                           ││
  │    %4  = (isa)(%2, Nothing)::Bool                                           ││
  │    %5  = (Core.Intrinsics.and_int)(%3, %4)::Bool                            ││
  └───       goto #3 if not %5                                                  ││
  2 ── %7  = %new(Main.NewInstruction, _3, _4, _5, nothing, nothing)::NewInstruction   NewInstruction
  └───       goto #10                                                           ││
  3 ── %9  = (isa)(%1, Int32)::Bool                                             ││
  │    %10 = (isa)(%2, Nothing)::Bool                                           ││
  │    %11 = (Core.Intrinsics.and_int)(%9, %10)::Bool                           ││
  └───       goto #5 if not %11                                                 ││
  4 ── %13 = π (%1, Int32)                                                      ││
  │    %14 = %new(Main.NewInstruction, _3, _4, _5, %13, nothing)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  5 ── %16 = (isa)(%1, Nothing)::Bool                                           ││
  │    %17 = (isa)(%2, UInt8)::Bool                                             ││
  │    %18 = (Core.Intrinsics.and_int)(%16, %17)::Bool                          ││
  └───       goto #7 if not %18                                                 ││
  6 ── %20 = π (%2, UInt8)                                                      ││
  │    %21 = %new(Main.NewInstruction, _3, _4, _5, nothing, %20)::NewInstruction│││╻   NewInstruction
  └───       goto #10                                                           ││
  7 ── %23 = (isa)(%1, Int32)::Bool                                             ││
  │    %24 = (isa)(%2, UInt8)::Bool                                             ││
  │    %25 = (Core.Intrinsics.and_int)(%23, %24)::Bool                          ││
  └───       goto #9 if not %25                                                 ││
  8 ── %27 = π (%1, Int32)                                                      ││
  │    %28 = π (%2, UInt8)                                                      ││
  │    %29 = %new(Main.NewInstruction, _3, _4, _5, %27, %28)::NewInstruction    │││╻   NewInstruction
  └───       goto #10                                                           ││
  9 ──       Core.throw(ErrorException("fatal error in type inference (type bound)"))::Union{}
  └───       unreachable                                                        ││
  10 ┄ %33 = φ (#2 => %7, #4 => %14, #6 => %21, #8 => %29)::NewInstruction      ││
  └───       goto #11                                                           ││
  11 ─       return %33                                                         │
   => NewInstruction
```
github-merge-queue bot pushed a commit that referenced this issue Jul 15, 2023
…d and inlined) (#43322)

A follow up attemp to fix #27988. (close #47493 close #50554)
Examples:
```julia
julia> using LazyArrays
julia> bc = @~ @. 1*(1 + 1) + 1*1;
julia> bc2 = @~ 1 .* 1 .- 1 .* 1 .^2 .+ 1 .* 1 .+ 1 .^ 3;
```
On master:
<details><summary> click for details </summary>
<p>

```julia
julia> @code_typed Broadcast.flatten(bc).f(1,1,1,1,1)
CodeInfo(
1 ─ %1  = Core.getfield(args, 1)::Int64
│   %2  = Core.getfield(args, 2)::Int64
│   %3  = Core.getfield(args, 3)::Int64
│   %4  = Core.getfield(args, 4)::Int64
│   %5  = Core.getfield(args, 5)::Int64
│   %6  = invoke Base.Broadcast.var"#13#14"{Base.Broadcast.var"#16#18"{Base.Broadcast.var"#15#17", Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}, Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}, Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}, typeof(+)}}(Base.Broadcast.var"#16#18"{Base.Broadcast.var"#15#17", Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}, Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}, Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}, typeof(+)}(Base.Broadcast.var"#15#17"(), Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}(Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}(Base.Broadcast.var"#15#17"())), Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}(Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}(Base.Broadcast.var"#25#26"())), Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}(Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}(Base.Broadcast.var"#21#22"())), +))(%1::Int64, %2::Int64, %3::Vararg{Int64}, %4, %5)::Tuple{Int64, Int64, Vararg{Int64}}
│   %7  = Core._apply_iterate(Base.iterate, Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}(Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}(Base.Broadcast.var"#21#22"())), %6)::Tuple{Int64, Int64}
│   %8  = Core._apply_iterate(Base.iterate, Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}(Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}(Base.Broadcast.var"#25#26"())), %6)::Tuple{Vararg{Int64}}
│   %9  = Core._apply_iterate(Base.iterate, Base.Broadcast.var"#16#18"{Base.Broadcast.var"#9#11", Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}, Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}, Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}, typeof(*)}(Base.Broadcast.var"#9#11"(), Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}(Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}(Base.Broadcast.var"#15#17"())), Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}(Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}(Base.Broadcast.var"#25#26"())), Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}(Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}(Base.Broadcast.var"#21#22"())), *), %8)::Tuple{Int64}
│   %10 = Core.getfield(%7, 1)::Int64
│   %11 = Core.getfield(%7, 2)::Int64
│   %12 = Base.mul_int(%10, %11)::Int64
│   %13 = Core.getfield(%9, 1)::Int64
│   %14 = Base.add_int(%12, %13)::Int64
└──       return %14
) => Int64

julia> @code_typed Broadcast.flatten(bc2).f(1,1,1,^,1,Val(2),1,1,^,1,Val(3))
CodeInfo(
1 ─ %1  = Core.getfield(args, 1)::Int64
│   %2  = Core.getfield(args, 2)::Int64
│   %3  = Core.getfield(args, 3)::Int64
│   %4  = Core.getfield(args, 5)::Int64
│   %5  = Core.getfield(args, 7)::Int64
│   %6  = Core.getfield(args, 8)::Int64
│   %7  = Core.getfield(args, 10)::Int64
│   %8  = invoke Base.Broadcast.var"#13#14"{Base.Broadcast.var"#16#18"{Base.Broadcast.var"#15#17", Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}}, Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}}, Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}}, typeof(Base.literal_pow)}}(Base.Broadcast.var"#16#18"{Base.Broadcast.var"#15#17", Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}}, Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}}, Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}}, typeof(Base.literal_pow)}(Base.Broadcast.var"#15#17"(), Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}}(Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}(Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}(Base.Broadcast.var"#15#17"()))), Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}}(Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}(Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}(Base.Broadcast.var"#25#26"()))), Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}}(Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}(Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}(Base.Broadcast.var"#21#22"()))), Base.literal_pow))(%3::Int64, ^::Function, %4::Vararg{Any}, $(QuoteNode(Val{2}())), %5, %6, ^, %7, $(QuoteNode(Val{3}())))::Tuple{Int64, Any, Vararg{Any}}
│   %9  = Core._apply_iterate(Base.iterate, Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}(Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}(Base.Broadcast.var"#21#22"())), %8)::Tuple{Int64, Any}
│   %10 = Core._apply_iterate(Base.iterate, Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}(Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}(Base.Broadcast.var"#25#26"())), %8)::Tuple
│   %11 = Core._apply_iterate(Base.iterate, Base.Broadcast.var"#15#17"(), %10)::Tuple
│   %12 = Core.getfield(%9, 1)::Int64
│   %13 = Core.getfield(%9, 2)::Any
│   %14 = (*)(%12, %13)::Any
│   %15 = Core.tuple(%14)::Tuple{Any}
│   %16 = Core._apply_iterate(Base.iterate, Core.tuple, %15, %11)::Tuple{Any, Vararg{Any}}
│   %17 = Base.mul_int(%1, %2)::Int64
│   %18 = Core.tuple(%17)::Tuple{Int64}
│   %19 = Core._apply_iterate(Base.iterate, Core.tuple, %18, %16)::Tuple{Int64, Any, Vararg{Any}}
│   %20 = Core._apply_iterate(Base.iterate, Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}(Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}(Base.Broadcast.var"#21#22"())), %19)::Tuple{Int64, Any}
│   %21 = Core._apply_iterate(Base.iterate, Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}(Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}(Base.Broadcast.var"#25#26"())), %19)::Tuple
│   %22 = Core._apply_iterate(Base.iterate, Base.Broadcast.var"#16#18"{Base.Broadcast.var"#15#17", Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}, Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}, Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}, typeof(*)}(Base.Broadcast.var"#15#17"(), Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}(Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}(Base.Broadcast.var"#15#17"())), Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}(Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}(Base.Broadcast.var"#25#26"())), Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}(Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}(Base.Broadcast.var"#21#22"())), *), %21)::Tuple{Any, Vararg{Any}}
│   %23 = Core.getfield(%20, 1)::Int64
│   %24 = Core.getfield(%20, 2)::Any
│   %25 = (-)(%23, %24)::Any
│   %26 = Core.tuple(%25)::Tuple{Any}
│   %27 = Core._apply_iterate(Base.iterate, Core.tuple, %26, %22)::Tuple{Any, Any, Vararg{Any}}
│   %28 = Core._apply_iterate(Base.iterate, Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}(Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}(Base.Broadcast.var"#21#22"())), %27)::Tuple{Any, Any}
│   %29 = Core._apply_iterate(Base.iterate, Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}(Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}(Base.Broadcast.var"#25#26"())), %27)::Tuple
│   %30 = Core._apply_iterate(Base.iterate, Base.Broadcast.var"#16#18"{Base.Broadcast.var"#9#11", Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}}, Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}}, Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}}, typeof(Base.literal_pow)}(Base.Broadcast.var"#9#11"(), Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}}(Base.Broadcast.var"#13#14"{Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}}(Base.Broadcast.var"#13#14"{Base.Broadcast.var"#15#17"}(Base.Broadcast.var"#15#17"()))), Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}}(Base.Broadcast.var"#23#24"{Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}}(Base.Broadcast.var"#23#24"{Base.Broadcast.var"#25#26"}(Base.Broadcast.var"#25#26"()))), Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}}(Base.Broadcast.var"#19#20"{Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}}(Base.Broadcast.var"#19#20"{Base.Broadcast.var"#21#22"}(Base.Broadcast.var"#21#22"()))), Base.literal_pow), %29)::Tuple{Any}
│   %31 = Core.getfield(%28, 1)::Any
│   %32 = Core.getfield(%28, 2)::Any
│   %33 = (+)(%31, %32)::Any
│   %34 = Core.getfield(%30, 1)::Any
│   %35 = (+)(%33, %34)::Any
└──       return %35
) => Any
```
</p>

</details>

On this PR
```julia
julia> @code_typed Broadcast.flatten(bc).f(1,1,1,1,1)
CodeInfo(
1 ─ %1 = Core.getfield(args, 1)::Int64
│   %2 = Core.getfield(args, 2)::Int64
│   %3 = Core.getfield(args, 3)::Int64
│   %4 = Core.getfield(args, 4)::Int64
│   %5 = Core.getfield(args, 5)::Int64
│   %6 = Base.add_int(%2, %3)::Int64
│   %7 = Base.mul_int(%1, %6)::Int64
│   %8 = Base.mul_int(%4, %5)::Int64
│   %9 = Base.add_int(%7, %8)::Int64
└──      return %9
) => Int64

julia> @code_typed Broadcast.flatten(bc2).f(1,1,1,^,1,Val(2),1,1,^,1,Val(3))
CodeInfo(
1 ─ %1  = Core.getfield(args, 1)::Int64
│   %2  = Core.getfield(args, 2)::Int64
│   %3  = Core.getfield(args, 3)::Int64
│   %4  = Core.getfield(args, 5)::Int64
│   %5  = Core.getfield(args, 7)::Int64
│   %6  = Core.getfield(args, 8)::Int64
│   %7  = Core.getfield(args, 10)::Int64
│   %8  = Base.mul_int(%1, %2)::Int64
│   %9  = Base.mul_int(%4, %4)::Int64
│   %10 = Base.mul_int(%3, %9)::Int64
│   %11 = Base.sub_int(%8, %10)::Int64
│   %12 = Base.mul_int(%5, %6)::Int64
│   %13 = Base.add_int(%11, %12)::Int64
│   %14 = Base.mul_int(%7, %7)::Int64
│   %15 = Base.mul_int(%14, %7)::Int64
│   %16 = Base.add_int(%13, %15)::Int64
└──       return %16
) => Int64
```
Keno pushed a commit that referenced this issue Oct 9, 2023
Handle :splatnew expressions on nightly
quinnj pushed a commit that referenced this issue Jan 26, 2024
`@something` eagerly unwraps any `Some` given to it, while keeping the
variable between its arguments the same. This can be an issue if a
previously unpacked value is used as input to `@something`, leading to a
type instability on more than two arguments (e.g. because of a fallback
to `Some(nothing)`). By using different variables for each argument,
type inference has an easier time handling these cases that are isolated
to single branches anyway.

This also adds some comments to the macro, since it's non-obvious what
it does.

Benchmarking the specific case I encountered this in led to a ~2x
performance improvement on multiple machines.

1.10-beta3/master:

```
[sukera@tower 01]$ jl1100 -q --project=. -L 01.jl -e 'bench()'
v"1.10.0-beta3"

BenchmarkTools.Trial: 10000 samples with 1 evaluation.
 Range (min … max):  38.670 μs … 70.350 μs  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     43.340 μs              ┊ GC (median):    0.00%
 Time  (mean ± σ):   43.395 μs ±  1.518 μs  ┊ GC (mean ± σ):  0.00% ± 0.00%

                              ▆█▂ ▁▁                           
  ▂▂▂▂▂▂▂▂▂▁▂▂▂▃▃▃▂▂▃▃▃▂▂▂▂▂▄▇███▆██▄▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂ ▃
  38.7 μs         Histogram: frequency by time          48 μs <

 Memory estimate: 0 bytes, allocs estimate: 0.
```

This PR:

```
[sukera@tower 01]$ julia -q --project=. -L 01.jl -e 'bench()'
v"1.11.0-DEV.970"

BenchmarkTools.Trial: 10000 samples with 1 evaluation.
 Range (min … max):  22.820 μs …  44.980 μs  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     24.300 μs               ┊ GC (median):    0.00%
 Time  (mean ± σ):   24.370 μs ± 832.239 ns  ┊ GC (mean ± σ):  0.00% ± 0.00%

                ▂▅▇██▇▆▅▁                                       
  ▂▂▂▂▂▂▂▂▃▃▄▅▇███████████▅▄▃▃▂▂▂▂▂▂▂▂▂▂▁▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▂▂ ▃
  22.8 μs         Histogram: frequency by time         27.7 μs <

 Memory estimate: 0 bytes, allocs estimate: 0.
``` 


<details>
<summary>Benchmarking code (spoilers for Advent Of Code 2023 Day 01,
Part 01). Running this requires the input of that Advent Of Code
day.</summary>

```julia
using BenchmarkTools
using InteractiveUtils

isdigit(d::UInt8) = UInt8('0') <= d <= UInt8('9')
someDigit(c::UInt8) = isdigit(c) ? Some(c - UInt8('0')) : nothing

function part1(data)
    total = 0
    may_a = nothing
    may_b = nothing

    for c in data
        digitRes = someDigit(c)
        may_a = @something may_a digitRes Some(nothing)
        may_b = @something digitRes may_b Some(nothing)
        if c == UInt8('\n')
            digit_a = may_a::UInt8
            digit_b = may_b::UInt8
            total += digit_a*0xa + digit_b
            may_a = nothing
            may_b = nothing
        end
    end

    return total
end

function bench()
    data = read("input.txt")
    display(VERSION)
    println()
    display(@benchmark part1($data))
    nothing
end
```
</details>

<details>
<summary>`@code_warntype` before</summary>

```julia
julia> @code_warntype part1(data)
MethodInstance for part1(::Vector{UInt8})
  from part1(data) @ Main ~/Documents/projects/AOC/2023/01/01.jl:7
Arguments
  #self#::Core.Const(part1)
  data::Vector{UInt8}
Locals
  @_3::Union{Nothing, Tuple{UInt8, Int64}}
  may_b::Union{Nothing, UInt8}
  may_a::Union{Nothing, UInt8}
  total::Int64
  c::UInt8
  digit_b::UInt8
  digit_a::UInt8
  val@_10::Any
  val@_11::Any
  digitRes::Union{Nothing, Some{UInt8}}
  @_13::Union{Some{Nothing}, Some{UInt8}, UInt8}
  @_14::Union{Some{Nothing}, Some{UInt8}}
  @_15::Some{Nothing}
  @_16::Union{Some{Nothing}, Some{UInt8}, UInt8}
  @_17::Union{Some{Nothing}, UInt8}
  @_18::Some{Nothing}
Body::Int64
1 ──       (total = 0)
│          (may_a = Main.nothing)
│          (may_b = Main.nothing)
│    %4  = data::Vector{UInt8}
│          (@_3 = Base.iterate(%4))
│    %6  = (@_3 === nothing)::Bool
│    %7  = Base.not_int(%6)::Bool
└───       goto #24 if not %7
2 ┄─       Core.NewvarNode(:(digit_b))
│          Core.NewvarNode(:(digit_a))
│          Core.NewvarNode(:(val@_10))
│    %12 = @_3::Tuple{UInt8, Int64}
│          (c = Core.getfield(%12, 1))
│    %14 = Core.getfield(%12, 2)::Int64
│          (digitRes = Main.someDigit(c))
│          (val@_11 = may_a)
│    %17 = (val@_11::Union{Nothing, UInt8} !== Base.nothing)::Bool
└───       goto #4 if not %17
3 ──       (@_13 = val@_11::UInt8)
└───       goto #11
4 ──       (val@_11 = digitRes)
│    %22 = (val@_11::Union{Nothing, Some{UInt8}} !== Base.nothing)::Bool
└───       goto #6 if not %22
5 ──       (@_14 = val@_11::Some{UInt8})
└───       goto #10
6 ──       (val@_11 = Main.Some(Main.nothing))
│    %27 = (val@_11::Core.Const(Some(nothing)) !== Base.nothing)::Core.Const(true)
└───       goto #8 if not %27
7 ──       (@_15 = val@_11::Core.Const(Some(nothing)))
└───       goto #9
8 ──       Core.Const(:(@_15 = Base.nothing))
9 ┄─       (@_14 = @_15)
10 ┄       (@_13 = @_14)
11 ┄ %34 = @_13::Union{Some{Nothing}, Some{UInt8}, UInt8}
│          (may_a = Base.something(%34))
│          (val@_10 = digitRes)
│    %37 = (val@_10::Union{Nothing, Some{UInt8}} !== Base.nothing)::Bool
└───       goto #13 if not %37
12 ─       (@_16 = val@_10::Some{UInt8})
└───       goto #20
13 ─       (val@_10 = may_b)
│    %42 = (val@_10::Union{Nothing, UInt8} !== Base.nothing)::Bool
└───       goto #15 if not %42
14 ─       (@_17 = val@_10::UInt8)
└───       goto #19
15 ─       (val@_10 = Main.Some(Main.nothing))
│    %47 = (val@_10::Core.Const(Some(nothing)) !== Base.nothing)::Core.Const(true)
└───       goto #17 if not %47
16 ─       (@_18 = val@_10::Core.Const(Some(nothing)))
└───       goto #18
17 ─       Core.Const(:(@_18 = Base.nothing))
18 ┄       (@_17 = @_18)
19 ┄       (@_16 = @_17)
20 ┄ %54 = @_16::Union{Some{Nothing}, Some{UInt8}, UInt8}
│          (may_b = Base.something(%54))
│    %56 = c::UInt8
│    %57 = Main.UInt8('\n')::Core.Const(0x0a)
│    %58 = (%56 == %57)::Bool
└───       goto #22 if not %58
21 ─       (digit_a = Core.typeassert(may_a, Main.UInt8))
│          (digit_b = Core.typeassert(may_b, Main.UInt8))
│    %62 = total::Int64
│    %63 = (digit_a * 0x0a)::UInt8
│    %64 = (%63 + digit_b)::UInt8
│          (total = %62 + %64)
│          (may_a = Main.nothing)
└───       (may_b = Main.nothing)
22 ┄       (@_3 = Base.iterate(%4, %14))
│    %69 = (@_3 === nothing)::Bool
│    %70 = Base.not_int(%69)::Bool
└───       goto #24 if not %70
23 ─       goto #2
24 ┄       return total
```
</details>

<details>
<summary>`@code_native debuginfo=:none` Before </summary>

```julia
julia> @code_native debuginfo=:none part1(data)
	.text
	.file	"part1"
	.globl	julia_part1_418                 # -- Begin function julia_part1_418
	.p2align	4, 0x90
	.type	julia_part1_418,@function
julia_part1_418:                        # @julia_part1_418
# %bb.0:                                # %top
	push	rbp
	mov	rbp, rsp
	push	r15
	push	r14
	push	r13
	push	r12
	push	rbx
	sub	rsp, 40
	mov	rax, qword ptr [rdi + 8]
	test	rax, rax
	je	.LBB0_1
# %bb.2:                                # %L17
	mov	rcx, qword ptr [rdi]
	dec	rax
	mov	r10b, 1
	xor	r14d, r14d
                                        # implicit-def: $r12b
                                        # implicit-def: $r13b
                                        # implicit-def: $r9b
                                        # implicit-def: $sil
	mov	qword ptr [rbp - 64], rax       # 8-byte Spill
	mov	al, 1
	mov	dword ptr [rbp - 48], eax       # 4-byte Spill
                                        # implicit-def: $al
                                        # kill: killed $al
	xor	eax, eax
	mov	qword ptr [rbp - 56], rax       # 8-byte Spill
	mov	qword ptr [rbp - 72], rcx       # 8-byte Spill
                                        # implicit-def: $cl
	jmp	.LBB0_3
	.p2align	4, 0x90
.LBB0_8:                                #   in Loop: Header=BB0_3 Depth=1
	mov	dword ptr [rbp - 48], 0         # 4-byte Folded Spill
.LBB0_24:                               # %post_union_move
                                        #   in Loop: Header=BB0_3 Depth=1
	movzx	r13d, byte ptr [rbp - 41]       # 1-byte Folded Reload
	mov	r12d, r8d
	cmp	qword ptr [rbp - 64], r14       # 8-byte Folded Reload
	je	.LBB0_13
.LBB0_25:                               # %guard_exit113
                                        #   in Loop: Header=BB0_3 Depth=1
	inc	r14
	mov	r10d, ebx
.LBB0_3:                                # %L19
                                        # =>This Inner Loop Header: Depth=1
	mov	rax, qword ptr [rbp - 72]       # 8-byte Reload
	xor	ebx, ebx
	xor	edi, edi
	movzx	r15d, r9b
	movzx	ecx, cl
	movzx	esi, sil
	mov	r11b, 1
                                        # implicit-def: $r9b
	movzx	edx, byte ptr [rax + r14]
	lea	eax, [rdx - 58]
	lea	r8d, [rdx - 48]
	cmp	al, -10
	setae	bl
	setb	dil
	test	r10b, 1
	cmovne	r15d, edi
	mov	edi, 0
	cmovne	ecx, ebx
	mov	bl, 1
	cmovne	esi, edi
	test	r15b, 1
	jne	.LBB0_7
# %bb.4:                                # %L76
                                        #   in Loop: Header=BB0_3 Depth=1
	mov	r11b, 2
	test	cl, 1
	jne	.LBB0_5
# %bb.6:                                # %L78
                                        #   in Loop: Header=BB0_3 Depth=1
	mov	ebx, r10d
	mov	r9d, r15d
	mov	byte ptr [rbp - 41], r13b       # 1-byte Spill
	test	sil, 1
	je	.LBB0_26
.LBB0_7:                                # %L82
                                        #   in Loop: Header=BB0_3 Depth=1
	cmp	al, -11
	jbe	.LBB0_9
	jmp	.LBB0_8
	.p2align	4, 0x90
.LBB0_5:                                #   in Loop: Header=BB0_3 Depth=1
	mov	ecx, r8d
	mov	sil, 1
	xor	ebx, ebx
	mov	byte ptr [rbp - 41], r8b        # 1-byte Spill
	xor	r9d, r9d
	xor	ecx, ecx
	cmp	al, -11
	ja	.LBB0_8
.LBB0_9:                                # %L90
                                        #   in Loop: Header=BB0_3 Depth=1
	test	byte ptr [rbp - 48], 1          # 1-byte Folded Reload
	jne	.LBB0_23
# %bb.10:                               # %L115
                                        #   in Loop: Header=BB0_3 Depth=1
	cmp	dl, 10
	jne	.LBB0_11
# %bb.14:                               # %L122
                                        #   in Loop: Header=BB0_3 Depth=1
	test	r15b, 1
	jne	.LBB0_15
# %bb.12:                               # %L130.thread
                                        #   in Loop: Header=BB0_3 Depth=1
	movzx	eax, byte ptr [rbp - 41]        # 1-byte Folded Reload
	mov	bl, 1
	add	eax, eax
	lea	eax, [rax + 4*rax]
	add	al, r12b
	movzx	eax, al
	add	qword ptr [rbp - 56], rax       # 8-byte Folded Spill
	mov	al, 1
	mov	dword ptr [rbp - 48], eax       # 4-byte Spill
	cmp	qword ptr [rbp - 64], r14       # 8-byte Folded Reload
	jne	.LBB0_25
	jmp	.LBB0_13
	.p2align	4, 0x90
.LBB0_23:                               # %L115.thread
                                        #   in Loop: Header=BB0_3 Depth=1
	mov	al, 1
                                        # implicit-def: $r8b
	mov	dword ptr [rbp - 48], eax       # 4-byte Spill
	cmp	dl, 10
	jne	.LBB0_24
	jmp	.LBB0_21
.LBB0_11:                               #   in Loop: Header=BB0_3 Depth=1
	mov	r8d, r12d
	jmp	.LBB0_24
.LBB0_1:
	xor	eax, eax
	mov	qword ptr [rbp - 56], rax       # 8-byte Spill
.LBB0_13:                               # %L159
	mov	rax, qword ptr [rbp - 56]       # 8-byte Reload
	add	rsp, 40
	pop	rbx
	pop	r12
	pop	r13
	pop	r14
	pop	r15
	pop	rbp
	ret
.LBB0_21:                               # %L122.thread
	test	r15b, 1
	jne	.LBB0_15
# %bb.22:                               # %post_box_union58
	movabs	rdi, offset .L_j_str1
	movabs	rax, offset ijl_type_error
	movabs	rsi, 140008511215408
	movabs	rdx, 140008667209736
	call	rax
.LBB0_15:                               # %fail
	cmp	r11b, 1
	je	.LBB0_19
# %bb.16:                               # %fail
	movzx	eax, r11b
	cmp	eax, 2
	jne	.LBB0_17
# %bb.20:                               # %box_union54
	movzx	eax, byte ptr [rbp - 41]        # 1-byte Folded Reload
	movabs	rcx, offset jl_boxed_uint8_cache
	mov	rdx, qword ptr [rcx + 8*rax]
	jmp	.LBB0_18
.LBB0_26:                               # %L80
	movabs	rax, offset ijl_throw
	movabs	rdi, 140008495049392
	call	rax
.LBB0_19:                               # %box_union
	movabs	rdx, 140008667209736
	jmp	.LBB0_18
.LBB0_17:
	xor	edx, edx
.LBB0_18:                               # %post_box_union
	movabs	rdi, offset .L_j_str1
	movabs	rax, offset ijl_type_error
	movabs	rsi, 140008511215408
	call	rax
.Lfunc_end0:
	.size	julia_part1_418, .Lfunc_end0-julia_part1_418
                                        # -- End function
	.type	.L_j_str1,@object               # @_j_str1
	.section	.rodata.str1.1,"aMS",@progbits,1
.L_j_str1:
	.asciz	"typeassert"
	.size	.L_j_str1, 11

	.section	".note.GNU-stack","",@progbits
```
</details>

<details>
<summary>`@code_warntype` After</summary>

```julia

[sukera@tower 01]$ julia -q --project=. -L 01.jl
julia> data = read("input.txt");

julia> @code_warntype part1(data)
MethodInstance for part1(::Vector{UInt8})
  from part1(data) @ Main ~/Documents/projects/AOC/2023/01/01.jl:7
Arguments
  #self#::Core.Const(part1)
  data::Vector{UInt8}
Locals
  @_3::Union{Nothing, Tuple{UInt8, Int64}}
  may_b::Union{Nothing, UInt8}
  may_a::Union{Nothing, UInt8}
  total::Int64
  val@_7::Union{}
  val@_8::Union{}
  c::UInt8
  digit_b::UInt8
  digit_a::UInt8
  ##215::Some{Nothing}
  ##216::Union{Nothing, UInt8}
  ##217::Union{Nothing, Some{UInt8}}
  ##212::Some{Nothing}
  ##213::Union{Nothing, Some{UInt8}}
  ##214::Union{Nothing, UInt8}
  digitRes::Union{Nothing, Some{UInt8}}
  @_19::Union{Nothing, UInt8}
  @_20::Union{Nothing, UInt8}
  @_21::Nothing
  @_22::Union{Nothing, UInt8}
  @_23::Union{Nothing, UInt8}
  @_24::Nothing
Body::Int64
1 ──        (total = 0)
│           (may_a = Main.nothing)
│           (may_b = Main.nothing)
│    %4   = data::Vector{UInt8}
│           (@_3 = Base.iterate(%4))
│    %6   = @_3::Union{Nothing, Tuple{UInt8, Int64}}
│    %7   = (%6 === nothing)::Bool
│    %8   = Base.not_int(%7)::Bool
└───        goto #24 if not %8
2 ┄─        Core.NewvarNode(:(val@_7))
│           Core.NewvarNode(:(val@_8))
│           Core.NewvarNode(:(digit_b))
│           Core.NewvarNode(:(digit_a))
│           Core.NewvarNode(:(##215))
│           Core.NewvarNode(:(##216))
│           Core.NewvarNode(:(##217))
│           Core.NewvarNode(:(##212))
│           Core.NewvarNode(:(##213))
│    %19  = @_3::Tuple{UInt8, Int64}
│           (c = Core.getfield(%19, 1))
│    %21  = Core.getfield(%19, 2)::Int64
│    %22  = c::UInt8
│           (digitRes = Main.someDigit(%22))
│    %24  = may_a::Union{Nothing, UInt8}
│           (##214 = %24)
│    %26  = Base.:!::Core.Const(!)
│    %27  = ##214::Union{Nothing, UInt8}
│    %28  = Base.isnothing(%27)::Bool
│    %29  = (%26)(%28)::Bool
└───        goto #4 if not %29
3 ── %31  = ##214::UInt8
│           (@_19 = Base.something(%31))
└───        goto #11
4 ── %34  = digitRes::Union{Nothing, Some{UInt8}}
│           (##213 = %34)
│    %36  = Base.:!::Core.Const(!)
│    %37  = ##213::Union{Nothing, Some{UInt8}}
│    %38  = Base.isnothing(%37)::Bool
│    %39  = (%36)(%38)::Bool
└───        goto #6 if not %39
5 ── %41  = ##213::Some{UInt8}
│           (@_20 = Base.something(%41))
└───        goto #10
6 ── %44  = Main.Some::Core.Const(Some)
│    %45  = Main.nothing::Core.Const(nothing)
│           (##212 = (%44)(%45))
│    %47  = Base.:!::Core.Const(!)
│    %48  = ##212::Core.Const(Some(nothing))
│    %49  = Base.isnothing(%48)::Core.Const(false)
│    %50  = (%47)(%49)::Core.Const(true)
└───        goto #8 if not %50
7 ── %52  = ##212::Core.Const(Some(nothing))
│           (@_21 = Base.something(%52))
└───        goto #9
8 ──        Core.Const(nothing)
│           Core.Const(:(val@_8 = Base.something(Base.nothing)))
│           Core.Const(nothing)
│           Core.Const(:(val@_8))
└───        Core.Const(:(@_21 = %58))
9 ┄─ %60  = @_21::Core.Const(nothing)
└───        (@_20 = %60)
10 ┄ %62  = @_20::Union{Nothing, UInt8}
└───        (@_19 = %62)
11 ┄ %64  = @_19::Union{Nothing, UInt8}
│           (may_a = %64)
│    %66  = digitRes::Union{Nothing, Some{UInt8}}
│           (##217 = %66)
│    %68  = Base.:!::Core.Const(!)
│    %69  = ##217::Union{Nothing, Some{UInt8}}
│    %70  = Base.isnothing(%69)::Bool
│    %71  = (%68)(%70)::Bool
└───        goto #13 if not %71
12 ─ %73  = ##217::Some{UInt8}
│           (@_22 = Base.something(%73))
└───        goto #20
13 ─ %76  = may_b::Union{Nothing, UInt8}
│           (##216 = %76)
│    %78  = Base.:!::Core.Const(!)
│    %79  = ##216::Union{Nothing, UInt8}
│    %80  = Base.isnothing(%79)::Bool
│    %81  = (%78)(%80)::Bool
└───        goto #15 if not %81
14 ─ %83  = ##216::UInt8
│           (@_23 = Base.something(%83))
└───        goto #19
15 ─ %86  = Main.Some::Core.Const(Some)
│    %87  = Main.nothing::Core.Const(nothing)
│           (##215 = (%86)(%87))
│    %89  = Base.:!::Core.Const(!)
│    %90  = ##215::Core.Const(Some(nothing))
│    %91  = Base.isnothing(%90)::Core.Const(false)
│    %92  = (%89)(%91)::Core.Const(true)
└───        goto #17 if not %92
16 ─ %94  = ##215::Core.Const(Some(nothing))
│           (@_24 = Base.something(%94))
└───        goto #18
17 ─        Core.Const(nothing)
│           Core.Const(:(val@_7 = Base.something(Base.nothing)))
│           Core.Const(nothing)
│           Core.Const(:(val@_7))
└───        Core.Const(:(@_24 = %100))
18 ┄ %102 = @_24::Core.Const(nothing)
└───        (@_23 = %102)
19 ┄ %104 = @_23::Union{Nothing, UInt8}
└───        (@_22 = %104)
20 ┄ %106 = @_22::Union{Nothing, UInt8}
│           (may_b = %106)
│    %108 = Main.:(==)::Core.Const(==)
│    %109 = c::UInt8
│    %110 = Main.UInt8('\n')::Core.Const(0x0a)
│    %111 = (%108)(%109, %110)::Bool
└───        goto #22 if not %111
21 ─ %113 = may_a::Union{Nothing, UInt8}
│           (digit_a = Core.typeassert(%113, Main.UInt8))
│    %115 = may_b::Union{Nothing, UInt8}
│           (digit_b = Core.typeassert(%115, Main.UInt8))
│    %117 = Main.:+::Core.Const(+)
│    %118 = total::Int64
│    %119 = Main.:+::Core.Const(+)
│    %120 = Main.:*::Core.Const(*)
│    %121 = digit_a::UInt8
│    %122 = (%120)(%121, 0x0a)::UInt8
│    %123 = digit_b::UInt8
│    %124 = (%119)(%122, %123)::UInt8
│           (total = (%117)(%118, %124))
│           (may_a = Main.nothing)
└───        (may_b = Main.nothing)
22 ┄        (@_3 = Base.iterate(%4, %21))
│    %129 = @_3::Union{Nothing, Tuple{UInt8, Int64}}
│    %130 = (%129 === nothing)::Bool
│    %131 = Base.not_int(%130)::Bool
└───        goto #24 if not %131
23 ─        goto #2
24 ┄ %134 = total::Int64
└───        return %134
```
</details>


<details>
<summary>`@code_native debuginfo=:none` After </summary>

```julia

julia> @code_native debuginfo=:none part1(data)
	.text
	.file	"part1"
	.globl	julia_part1_1203                # -- Begin function julia_part1_1203
	.p2align	4, 0x90
	.type	julia_part1_1203,@function
julia_part1_1203:                       # @julia_part1_1203
; Function Signature: part1(Array{UInt8, 1})
# %bb.0:                                # %top
	#DEBUG_VALUE: part1:data <- [DW_OP_deref] $rdi
	push	rbp
	mov	rbp, rsp
	push	r15
	push	r14
	push	r13
	push	r12
	push	rbx
	sub	rsp, 40
	vxorps	xmm0, xmm0, xmm0
	#APP
	mov	rax, qword ptr fs:[0]
	#NO_APP
	lea	rdx, [rbp - 64]
	vmovaps	xmmword ptr [rbp - 64], xmm0
	mov	qword ptr [rbp - 48], 0
	mov	rcx, qword ptr [rax - 8]
	mov	qword ptr [rbp - 64], 4
	mov	rax, qword ptr [rcx]
	mov	qword ptr [rbp - 72], rcx       # 8-byte Spill
	mov	qword ptr [rbp - 56], rax
	mov	qword ptr [rcx], rdx
	#DEBUG_VALUE: part1:data <- [DW_OP_deref] 0
	mov	r15, qword ptr [rdi + 16]
	test	r15, r15
	je	.LBB0_1
# %bb.2:                                # %L34
	mov	r14, qword ptr [rdi]
	dec	r15
	mov	r11b, 1
	mov	r13b, 1
                                        # implicit-def: $r12b
                                        # implicit-def: $r10b
	xor	eax, eax
	jmp	.LBB0_3
	.p2align	4, 0x90
.LBB0_4:                                #   in Loop: Header=BB0_3 Depth=1
	xor	r11d, r11d
	mov	ebx, edi
	mov	r10d, r8d
.LBB0_9:                                # %L114
                                        #   in Loop: Header=BB0_3 Depth=1
	mov	r12d, esi
	test	r15, r15
	je	.LBB0_12
.LBB0_10:                               # %guard_exit126
                                        #   in Loop: Header=BB0_3 Depth=1
	inc	r14
	dec	r15
	mov	r13d, ebx
.LBB0_3:                                # %L36
                                        # =>This Inner Loop Header: Depth=1
	movzx	edx, byte ptr [r14]
	test	r13b, 1
	movzx	edi, r13b
	mov	ebx, 1
	mov	ecx, 0
	cmove	ebx, edi
	cmovne	edi, ecx
	movzx	ecx, r10b
	lea	esi, [rdx - 48]
	lea	r9d, [rdx - 58]
	movzx	r8d, sil
	cmove	r8d, ecx
	cmp	r9b, -11
	ja	.LBB0_4
# %bb.5:                                # %L89
                                        #   in Loop: Header=BB0_3 Depth=1
	test	r11b, 1
	jne	.LBB0_8
# %bb.6:                                # %L102
                                        #   in Loop: Header=BB0_3 Depth=1
	cmp	dl, 10
	jne	.LBB0_7
# %bb.13:                               # %L106
                                        #   in Loop: Header=BB0_3 Depth=1
	test	r13b, 1
	jne	.LBB0_14
# %bb.11:                               # %L114.thread
                                        #   in Loop: Header=BB0_3 Depth=1
	add	ecx, ecx
	mov	bl, 1
	mov	r11b, 1
	lea	ecx, [rcx + 4*rcx]
	add	cl, r12b
	movzx	ecx, cl
	add	rax, rcx
	test	r15, r15
	jne	.LBB0_10
	jmp	.LBB0_12
	.p2align	4, 0x90
.LBB0_8:                                # %L102.thread
                                        #   in Loop: Header=BB0_3 Depth=1
	mov	r11b, 1
                                        # implicit-def: $sil
	cmp	dl, 10
	jne	.LBB0_9
	jmp	.LBB0_15
.LBB0_7:                                #   in Loop: Header=BB0_3 Depth=1
	mov	esi, r12d
	jmp	.LBB0_9
.LBB0_1:
	xor	eax, eax
.LBB0_12:                               # %L154
	mov	rcx, qword ptr [rbp - 56]
	mov	rdx, qword ptr [rbp - 72]       # 8-byte Reload
	mov	qword ptr [rdx], rcx
	add	rsp, 40
	pop	rbx
	pop	r12
	pop	r13
	pop	r14
	pop	r15
	pop	rbp
	ret
.LBB0_15:                               # %L106.thread
	test	r13b, 1
	jne	.LBB0_14
# %bb.16:                               # %post_box_union47
	movabs	rax, offset jl_nothing
	movabs	rcx, offset jl_small_typeof
	movabs	rdi, offset ".L_j_str_typeassert#1"
	mov	rdx, qword ptr [rax]
	mov	rsi, qword ptr [rcx + 336]
	movabs	rax, offset ijl_type_error
	mov	qword ptr [rbp - 48], rsi
	call	rax
.LBB0_14:                               # %post_box_union
	movabs	rax, offset jl_nothing
	movabs	rcx, offset jl_small_typeof
	movabs	rdi, offset ".L_j_str_typeassert#1"
	mov	rdx, qword ptr [rax]
	mov	rsi, qword ptr [rcx + 336]
	movabs	rax, offset ijl_type_error
	mov	qword ptr [rbp - 48], rsi
	call	rax
.Lfunc_end0:
	.size	julia_part1_1203, .Lfunc_end0-julia_part1_1203
                                        # -- End function
	.type	".L_j_str_typeassert#1",@object # @"_j_str_typeassert#1"
	.section	.rodata.str1.1,"aMS",@progbits,1
".L_j_str_typeassert#1":
	.asciz	"typeassert"
	.size	".L_j_str_typeassert#1", 11

	.section	".note.GNU-stack","",@progbits
```
</details>

Co-authored-by: Sukera <[email protected]>
aviatesk added a commit that referenced this issue Oct 1, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 1, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
vtjnash pushed a commit that referenced this issue Oct 1, 2024
`memoryref(mem, i)` will otherwise emit a boundscheck.

```
; │ @ /home/vchuravy/WorkstealingQueues/src/CLL.jl:53 within `setindex_atomic!` @ genericmemory.jl:329
; │┌ @ boot.jl:545 within `memoryref`
    %ptls_field = getelementptr inbounds i8, ptr %tls_pgcstack, i64 16
    %ptls_load = load ptr, ptr %ptls_field, align 8
    %"box::GenericMemoryRef" = call noalias nonnull align 8 dereferenceable(32) ptr @ijl_gc_small_alloc(ptr %ptls_load, i32 552, i32 32, i64 23456076646928) #9
    %"box::GenericMemoryRef.tag_addr" = getelementptr inbounds i64, ptr %"box::GenericMemoryRef", i64 -1
    store atomic i64 23456076646928, ptr %"box::GenericMemoryRef.tag_addr" unordered, align 8
    store ptr %memoryref_data, ptr %"box::GenericMemoryRef", align 8
    %.repack8 = getelementptr inbounds { ptr, ptr }, ptr %"box::GenericMemoryRef", i64 0, i32 1
    store ptr %memoryref_mem, ptr %.repack8, align 8
    call void @ijl_bounds_error_int(ptr nonnull %"box::GenericMemoryRef", i64 %7)
    unreachable
```

For the Julia code:

```julia
function Base.setindex_atomic!(buf::WSBuffer{T}, order::Symbol, val::T, idx::Int64) where T
    @inbounds Base.setindex_atomic!(buf.buffer, order, val,((idx - 1) & buf.mask) + 1)
end
```

from
https://github.com/gbaraldi/WorkstealingQueues.jl/blob/0ebc57237cf0c90feedf99e4338577d04b67805b/src/CLL.jl#L41
aviatesk added a commit that referenced this issue Oct 2, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 2, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 2, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 4, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 4, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 4, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 5, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 9, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 11, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 11, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 12, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 15, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 16, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked as
`broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical.
In particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
  for limited frames because of latency reasons, which significantly
  reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
  algorithm requires `:nothrow`-ness on all paths from the allocation of
  the mutable struct to its last use, which is not practical for
  real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
  optimizations such as inserting a `finalize` call after the last use
  might still be possible.
aviatesk added a commit that referenced this issue Oct 16, 2024
E.g. this allows `finalizer` inlining in the following case:
```julia
mutable struct ForeignBuffer{T}
    const ptr::Ptr{T}
end
const foreign_buffer_finalized = Ref(false)
function foreign_alloc(::Type{T}, length) where T
    ptr = Libc.malloc(sizeof(T) * length)
    ptr = Base.unsafe_convert(Ptr{T}, ptr)
    obj = ForeignBuffer{T}(ptr)
    return finalizer(obj) do obj
        Base.@assume_effects :notaskstate :nothrow
        foreign_buffer_finalized[] = true
        Libc.free(obj.ptr)
    end
end
function f_EA_finalizer(N::Int)
    workspace = foreign_alloc(Float64, N)
    GC.@preserve workspace begin
        (;ptr) = workspace
        Base.@assume_effects :nothrow @noinline println(devnull, "ptr = ", ptr)
    end
end
```
```julia
julia> @code_typed f_EA_finalizer(42)
CodeInfo(
1 ── %1  = Base.mul_int(8, N)::Int64
│    %2  = Core.lshr_int(%1, 63)::Int64
│    %3  = Core.trunc_int(Core.UInt8, %2)::UInt8
│    %4  = Core.eq_int(%3, 0x01)::Bool
└───       goto #3 if not %4
2 ──       invoke Core.throw_inexacterror(:convert::Symbol, UInt64::Type, %1::Int64)::Union{}
└───       unreachable
3 ──       goto #4
4 ── %9  = Core.bitcast(Core.UInt64, %1)::UInt64
└───       goto #5
5 ──       goto #6
6 ──       goto #7
7 ──       goto #8
8 ── %14 = $(Expr(:foreigncall, :(:malloc), Ptr{Nothing}, svec(UInt64), 0, :(:ccall), :(%9), :(%9)))::Ptr{Nothing}
└───       goto #9
9 ── %16 = Base.bitcast(Ptr{Float64}, %14)::Ptr{Float64}
│    %17 = %new(ForeignBuffer{Float64}, %16)::ForeignBuffer{Float64}
└───       goto #10
10 ─ %19 = $(Expr(:gc_preserve_begin, :(%17)))
│    %20 = Base.getfield(%17, :ptr)::Ptr{Float64}
│          invoke Main.println(Main.devnull::Base.DevNull, "ptr = "::String, %20::Ptr{Float64})::Nothing
│          $(Expr(:gc_preserve_end, :(%19)))
│    %23 = Main.foreign_buffer_finalized::Base.RefValue{Bool}
│          Base.setfield!(%23, :x, true)::Bool
│    %25 = Base.getfield(%17, :ptr)::Ptr{Float64}
│    %26 = Base.bitcast(Ptr{Nothing}, %25)::Ptr{Nothing}
│          $(Expr(:foreigncall, :(:free), Nothing, svec(Ptr{Nothing}), 0, :(:ccall), :(%26), :(%25)))::Nothing
└───       return nothing
) => Nothing
```

However, this is still a WIP. Before merging, I want to improve EA's
precision a bit and at least fix the test case that is currently marked
as `broken`. I also need to check its impact on compiler performance.

Additionally, I believe this feature is not yet practical. In
particular, there is still significant room for improvement in the
following areas:
- EA's interprocedural capabilities: currently EA is performed ad-hoc
for limited frames because of latency reasons, which significantly
reduces its precision in the presence of interprocedural calls.
- Relaxing the `:nothrow` check for finalizer inlining: the current
algorithm requires `:nothrow`-ness on all paths from the allocation of
the mutable struct to its last use, which is not practical for
real-world cases. Even when `:nothrow` cannot be guaranteed, auxiliary
optimizations such as inserting a `finalize` call after the last use
might still be possible (#55990).
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