cmd/compile: more fix on boolean ops on ARM64

Following CL 405114, the extension rule is also wrong. It is safe
to drop the extension if the value is from a boolean-generating
instruction, but not a boolean-typed Value in general (e.g. a Phi
or a in-register parameter). Fix it.

Updates #52788.

Change-Id: Icf3028fe8e90806f9f57fbe2b38d47da27a97e2a
Reviewed-on: https://go-review.googlesource.com/c/go/+/405115
Reviewed-by: David Chase <[email protected]>
Run-TryBot: Cherry Mui <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>

src/cmd/compile/internal/ssa/gen/ARM64.rules

@@ -1578,9 +1578,9 @@
 (GreaterThanF (InvertFlags x)) => (LessThanF x)
 (GreaterEqualF (InvertFlags x)) => (LessEqualF x)
 
-// Boolean-generating instructions always
+// Boolean-generating instructions (NOTE: NOT all boolean Values) always
 // zero upper bit of the register; no need to zero-extend
-(MOVBUreg x) && x.Type.IsBoolean() => (MOVDreg x)
+(MOVBUreg x:((Equal|NotEqual|LessThan|LessThanU|LessThanF|LessEqual|LessEqualU|LessEqualF|GreaterThan|GreaterThanU|GreaterThanF|GreaterEqual|GreaterEqualU|GreaterEqualF) _)) => (MOVDreg x)
 
 // absorb flag constants into conditional instructions
 (CSEL [cc] x _ flag) && ccARM64Eval(cc, flag) > 0 => x

test/fixedbugs/issue52788a.go

@@ -0,0 +1,29 @@
+// run
+
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Issue 52788: miscompilation for boolean ops on ARM64.
+
+package main
+
+import (
+	"fmt"
+	"reflect"
+	"os"
+)
+
+func f(next func() bool) {
+	for b := next(); b; b = next() {
+		fmt.Printf("%v\n", b)
+		os.Exit(0)
+	}
+}
+
+func main() {
+	next := reflect.MakeFunc(reflect.TypeOf((func() bool)(nil)), func(_ []reflect.Value) []reflect.Value {
+		return []reflect.Value{reflect.ValueOf(true)}
+	})
+	reflect.ValueOf(f).Call([]reflect.Value{next})
+}

test/fixedbugs/issue52788a.out

@@ -0,0 +1 @@
+true