https://github.com/kiran-isaac updated https://github.com/llvm/llvm-project/pull/178220
>From f1583f9e09febf7b3c2d9cec69df52514b30cd41 Mon Sep 17 00:00:00 2001 From: Kiran Sturt <[email protected]> Date: Tue, 30 Dec 2025 18:05:53 +0000 Subject: [PATCH 1/2] [Clang] Fix atomic boolean compound assignment (#33210) --- clang/lib/CodeGen/CGExprScalar.cpp | 7 ++++ .../CodeGen/compound-assign-atomic-bool.c | 33 +++++++++++++++++++ 2 files changed, 40 insertions(+) create mode 100644 clang/test/CodeGen/compound-assign-atomic-bool.c diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp index 11af497390671..0d92be12959a9 100644 --- a/clang/lib/CodeGen/CGExprScalar.cpp +++ b/clang/lib/CodeGen/CGExprScalar.cpp @@ -1591,6 +1591,13 @@ Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, if (DstType->isBooleanType()) return EmitConversionToBool(Src, SrcType); + // Also handle conversions to atomic bools + if (const AtomicType *atomicType = DstType->getAs<AtomicType>()) { + QualType ValueType = atomicType->getValueType(); + if (ValueType->isBooleanType()) + return EmitConversionToBool(Src, ValueType); + } + llvm::Type *DstTy = ConvertType(DstType); // Cast from half through float if half isn't a native type. diff --git a/clang/test/CodeGen/compound-assign-atomic-bool.c b/clang/test/CodeGen/compound-assign-atomic-bool.c new file mode 100644 index 0000000000000..8a39a76788e66 --- /dev/null +++ b/clang/test/CodeGen/compound-assign-atomic-bool.c @@ -0,0 +1,33 @@ +// RUN: %clang_cc1 -emit-llvm -o - %s | FileCheck %s + +// When performing compound assignment on atomic_bool, ensure that we +// correctly handle the conversion from integer to boolean, by comparing +// with zero rather than truncating. + +#include <stdatomic.h> +#include <stdbool.h> + + +// CHECK: @compund_assign_add +int compund_assign_add(void) { + atomic_bool b; + + b += 2; + // CHECK: add + // CHECK-NEXT: icmp ne + // CHECK-NEXT: zext + // CHECK-NEXT: cmpxchg + return b; +} + +// CHECK: @compund_assign_minus +int compund_assign_minus(void) { + atomic_bool b; + + b -= 2; + // CHECK: sub + // CHECK-NEXT: icmp ne + // CHECK-NEXT: zext + // CHECK-NEXT: cmpxchg + return b; +} >From f015dde439add64eaa0fd2cc168ac1c8de3b4866 Mon Sep 17 00:00:00 2001 From: Kiran Sturt <[email protected]> Date: Thu, 5 Feb 2026 15:54:56 +0000 Subject: [PATCH 2/2] Style changes, add release notes Change-Id: I98669a9543f0c93a08fa939655ebd12a2f321ae5 --- clang/docs/ReleaseNotes.rst | 3 +++ clang/lib/CodeGen/CGExprScalar.cpp | 4 ++-- clang/test/CodeGen/compound-assign-atomic-bool.c | 8 ++------ 3 files changed, 7 insertions(+), 8 deletions(-) diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 4d2ff6e6e4e40..4be4607a528c9 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -195,6 +195,9 @@ Improvements to Coverage Mapping Bug Fixes in This Version ------------------------- + +- Fixed atomic boolean compound assignment; the conversion back to atomic bool would be miscompiled. (#GH33210) + - Fixed a failed assertion in the preprocessor when ``__has_embed`` parameters are missing parentheses. (#GH175088) - Fix lifetime extension of temporaries in for-range-initializers in templates. (#GH165182) diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp index 0d92be12959a9..86fa740908f75 100644 --- a/clang/lib/CodeGen/CGExprScalar.cpp +++ b/clang/lib/CodeGen/CGExprScalar.cpp @@ -1592,8 +1592,8 @@ Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, return EmitConversionToBool(Src, SrcType); // Also handle conversions to atomic bools - if (const AtomicType *atomicType = DstType->getAs<AtomicType>()) { - QualType ValueType = atomicType->getValueType(); + if (const auto *DstAsAtomic = DstType->getAs<AtomicType>()) { + QualType ValueType = DstAsAtomic->getValueType(); if (ValueType->isBooleanType()) return EmitConversionToBool(Src, ValueType); } diff --git a/clang/test/CodeGen/compound-assign-atomic-bool.c b/clang/test/CodeGen/compound-assign-atomic-bool.c index 8a39a76788e66..4e8f351b49b81 100644 --- a/clang/test/CodeGen/compound-assign-atomic-bool.c +++ b/clang/test/CodeGen/compound-assign-atomic-bool.c @@ -4,13 +4,9 @@ // correctly handle the conversion from integer to boolean, by comparing // with zero rather than truncating. -#include <stdatomic.h> -#include <stdbool.h> - - // CHECK: @compund_assign_add int compund_assign_add(void) { - atomic_bool b; + _Atomic _Bool b; b += 2; // CHECK: add @@ -22,7 +18,7 @@ int compund_assign_add(void) { // CHECK: @compund_assign_minus int compund_assign_minus(void) { - atomic_bool b; + _Atomic _Bool b; b -= 2; // CHECK: sub _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
