diff --git a/compiler/rustc_codegen_gcc/src/builder.rs b/compiler/rustc_codegen_gcc/src/builder.rs index 43d0aafbd50bf..17e126967bef8 100644 --- a/compiler/rustc_codegen_gcc/src/builder.rs +++ b/compiler/rustc_codegen_gcc/src/builder.rs @@ -1421,7 +1421,7 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> { self.cx } - fn do_not_inline(&mut self, _llret: RValue<'gcc>) { + fn apply_attrs_to_cleanup_callsite(&mut self, _llret: RValue<'gcc>) { // FIXME(bjorn3): implement } diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs index b4aa001547c4c..8edc122d7b2b3 100644 --- a/compiler/rustc_codegen_llvm/src/builder.rs +++ b/compiler/rustc_codegen_llvm/src/builder.rs @@ -1221,9 +1221,11 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> { unsafe { llvm::LLVMBuildZExt(self.llbuilder, val, dest_ty, UNNAMED) } } - fn do_not_inline(&mut self, llret: &'ll Value) { - let noinline = llvm::AttributeKind::NoInline.create_attr(self.llcx); - attributes::apply_to_callsite(llret, llvm::AttributePlace::Function, &[noinline]); + fn apply_attrs_to_cleanup_callsite(&mut self, llret: &'ll Value) { + // Cleanup is always the cold path. + let cold_inline = llvm::AttributeKind::Cold.create_attr(self.llcx); + + attributes::apply_to_callsite(llret, llvm::AttributePlace::Function, &[cold_inline]); } } diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index 0cec560ba4518..a55081a955a62 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -204,7 +204,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> { self.funclet(fx), ); if fx.mir[self.bb].is_cleanup { - bx.do_not_inline(invokeret); + bx.apply_attrs_to_cleanup_callsite(invokeret); } if let Some((ret_dest, target)) = destination { @@ -219,11 +219,7 @@ impl<'a, 'tcx> TerminatorCodegenHelper<'tcx> { } else { let llret = bx.call(fn_ty, fn_attrs, Some(&fn_abi), fn_ptr, &llargs, self.funclet(fx)); if fx.mir[self.bb].is_cleanup { - // Cleanup is always the cold path. Don't inline - // drop glue. Also, when there is a deeply-nested - // struct, there are "symmetry" issues that cause - // exponential inlining - see issue #41696. - bx.do_not_inline(llret); + bx.apply_attrs_to_cleanup_callsite(llret); } if let Some((ret_dest, target)) = destination { @@ -1618,7 +1614,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { let fn_ty = bx.fn_decl_backend_type(&fn_abi); let llret = bx.call(fn_ty, None, Some(&fn_abi), fn_ptr, &[], funclet.as_ref()); - bx.do_not_inline(llret); + bx.apply_attrs_to_cleanup_callsite(llret); bx.unreachable(); diff --git a/compiler/rustc_codegen_ssa/src/traits/builder.rs b/compiler/rustc_codegen_ssa/src/traits/builder.rs index 853c6934c2c24..aa411f002a0c6 100644 --- a/compiler/rustc_codegen_ssa/src/traits/builder.rs +++ b/compiler/rustc_codegen_ssa/src/traits/builder.rs @@ -332,5 +332,5 @@ pub trait BuilderMethods<'a, 'tcx>: ) -> Self::Value; fn zext(&mut self, val: Self::Value, dest_ty: Self::Type) -> Self::Value; - fn do_not_inline(&mut self, llret: Self::Value); + fn apply_attrs_to_cleanup_callsite(&mut self, llret: Self::Value); } diff --git a/tests/codegen/issue-97217.rs b/tests/codegen/issue-97217.rs new file mode 100644 index 0000000000000..5558447cd1781 --- /dev/null +++ b/tests/codegen/issue-97217.rs @@ -0,0 +1,21 @@ +// compile-flags: -C opt-level=3 +// ignore-debug: the debug assertions get in the way +#![crate_type = "lib"] + +// Regression test for issue 97217 (the following should result in no allocations) + +// CHECK-LABEL: @issue97217 +#[no_mangle] +pub fn issue97217() -> i32 { + // drop_in_place should be inlined and never appear + // CHECK-NOT: drop_in_place + + // __rust_alloc should be optimized out + // CHECK-NOT: __rust_alloc + + let v1 = vec![5, 6, 7]; + let v1_iter = v1.iter(); + let total: i32 = v1_iter.sum(); + println!("{}",total); + total +} diff --git a/tests/codegen/unwind-landingpad-cold.rs b/tests/codegen/unwind-landingpad-cold.rs new file mode 100644 index 0000000000000..afebc31a23a39 --- /dev/null +++ b/tests/codegen/unwind-landingpad-cold.rs @@ -0,0 +1,14 @@ +// compile-flags: -Cno-prepopulate-passes +#![crate_type = "lib"] + +// This test checks that drop calls in unwind landing pads +// get the `cold` attribute. + +// CHECK-LABEL: @check_cold +// CHECK: {{(call|invoke) void .+}}drop_in_place{{.+}} [[ATTRIBUTES:#[0-9]+]] +// CHECK: attributes [[ATTRIBUTES]] = { cold } +#[no_mangle] +pub fn check_cold(f: fn(), x: Box) { + // this may unwind + f(); +} diff --git a/tests/codegen/unwind-landingpad-inline.rs b/tests/codegen/unwind-landingpad-inline.rs new file mode 100644 index 0000000000000..e11b212e52ea3 --- /dev/null +++ b/tests/codegen/unwind-landingpad-inline.rs @@ -0,0 +1,38 @@ +// min-llvm-version: 15.0.0 +// compile-flags: -Copt-level=3 +// ignore-debug: the debug assertions get in the way +#![crate_type = "lib"] + +// This test checks that we can inline drop_in_place in +// unwind landing pads. + +// Without inlining, the box pointers escape via the call to drop_in_place, +// and LLVM will not optimize out the pointer comparison. +// With inlining, everything should be optimized out. +// See https://github.com/rust-lang/rust/issues/46515 +// CHECK-LABEL: @check_no_escape_in_landingpad +// CHECK: start: +// CHECK-NEXT: ret void +#[no_mangle] +pub fn check_no_escape_in_landingpad(f: fn()) { + let x = &*Box::new(0); + let y = &*Box::new(0); + + if x as *const _ == y as *const _ { + f(); + } +} + +// Without inlining, the compiler can't tell that +// dropping an empty string (in a landing pad) does nothing. +// With inlining, the landing pad should be optimized out. +// See https://github.com/rust-lang/rust/issues/87055 +// CHECK-LABEL: @check_eliminate_noop_drop +// CHECK: start: +// CHECK-NEXT: call void %g() +// CHECK-NEXT: ret void +#[no_mangle] +pub fn check_eliminate_noop_drop(g: fn()) { + let _var = String::new(); + g(); +}