https://github.com/hstk30 updated https://github.com/llvm/llvm-project/pull/72197
>From 4c356e1d02ba2d0dbbfe0064173ba95db41fc698 Mon Sep 17 00:00:00 2001 From: hstk30 <[email protected]> Date: Fri, 10 Oct 2025 00:17:09 +0800 Subject: [PATCH] fix: C++ empty record with align break aarch64 AAPCS64 --- clang/lib/CodeGen/Targets/AArch64.cpp | 9 ++++++--- clang/test/CodeGen/AArch64/args.cpp | 2 +- clang/test/CodeGen/arm64-microsoft-arguments.cpp | 4 ++-- clang/test/CodeGenCXX/aarch64-arguments.cpp | 2 +- clang/test/CodeGenCXX/arm64-darwinpcs.cpp | 2 +- 5 files changed, 11 insertions(+), 8 deletions(-) diff --git a/clang/lib/CodeGen/Targets/AArch64.cpp b/clang/lib/CodeGen/Targets/AArch64.cpp index d7deece232a9f..9adace69c06c6 100644 --- a/clang/lib/CodeGen/Targets/AArch64.cpp +++ b/clang/lib/CodeGen/Targets/AArch64.cpp @@ -422,6 +422,12 @@ ABIArgInfo AArch64ABIInfo::classifyArgumentType(QualType Ty, bool IsVariadicFn, } // Empty records: + // AAPCS64 does not say that empty records are ignored as arguments, + // but other compilers do so in certain situations, and we copy that behavior. + // Those situations are in fact language-mode-specific, which seems really + // unfortunate, but it's something we just have to accept. If this doesn't + // apply, just fall through to the standard argument-handling path. + // Darwin overrides the psABI here to ignore all empty records in all modes. uint64_t Size = getContext().getTypeSize(Ty); bool IsEmpty = isEmptyRecord(getContext(), Ty, true); if (!Ty->isSVESizelessBuiltinType() && (IsEmpty || Size == 0)) { @@ -434,9 +440,6 @@ ABIArgInfo AArch64ABIInfo::classifyArgumentType(QualType Ty, bool IsVariadicFn, // behaviour here. if (Size == 0) return ABIArgInfo::getIgnore(); - - // Otherwise, they are passed as if they have a size of 1 byte. - return ABIArgInfo::getDirect(llvm::Type::getInt8Ty(getVMContext())); } // Homogeneous Floating-point Aggregates (HFAs) need to be expanded. diff --git a/clang/test/CodeGen/AArch64/args.cpp b/clang/test/CodeGen/AArch64/args.cpp index 3cb62d3119ecf..0f6f87db3f472 100644 --- a/clang/test/CodeGen/AArch64/args.cpp +++ b/clang/test/CodeGen/AArch64/args.cpp @@ -17,7 +17,7 @@ struct Empty {}; // DARWIN: define{{.*}} i32 @empty_arg(i32 noundef %a) // C: define{{.*}} i32 @empty_arg(i32 noundef %a) -// CXX: define{{.*}} i32 @empty_arg(i8 %e.coerce, i32 noundef %a) +// CXX: define{{.*}} i32 @empty_arg(i64 %e.coerce, i32 noundef %a) EXTERNC int empty_arg(struct Empty e, int a) { return a; } diff --git a/clang/test/CodeGen/arm64-microsoft-arguments.cpp b/clang/test/CodeGen/arm64-microsoft-arguments.cpp index a0a81be54325f..b771af83b6da0 100644 --- a/clang/test/CodeGen/arm64-microsoft-arguments.cpp +++ b/clang/test/CodeGen/arm64-microsoft-arguments.cpp @@ -57,7 +57,7 @@ S4 f4() { // Pass and return from instance method called from instance method. // CHECK: define {{.*}} void @{{.*}}bar@Q1{{.*}}(ptr {{[^,]*}} %this, ptr dead_on_unwind inreg noalias writable sret(%class.P1) align 1 %agg.result) -// CHECK: call void {{.*}}foo@P1{{.*}}(ptr noundef{{[^,]*}} %ref.tmp, ptr dead_on_unwind inreg writable sret(%class.P1) align 1 %agg.result, i8 %0) +// CHECK: call void {{.*}}foo@P1{{.*}}(ptr noundef{{[^,]*}} %ref.tmp, ptr dead_on_unwind inreg writable sret(%class.P1) align 1 %agg.result, i64 %0) class P1 { public: @@ -76,7 +76,7 @@ P1 Q1::bar() { // Pass and return from instance method called from free function. // CHECK: define {{.*}} void {{.*}}bar{{.*}}() -// CHECK: call void {{.*}}foo@P2{{.*}}(ptr noundef{{[^,]*}} %ref.tmp, ptr dead_on_unwind inreg writable sret(%class.P2) align 1 %retval, i8 %0) +// CHECK: call void {{.*}}foo@P2{{.*}}(ptr noundef{{[^,]*}} %ref.tmp, ptr dead_on_unwind inreg writable sret(%class.P2) align 1 %retval, i64 %0) class P2 { public: P2 foo(P2 x); diff --git a/clang/test/CodeGenCXX/aarch64-arguments.cpp b/clang/test/CodeGenCXX/aarch64-arguments.cpp index ffb0cafa8882d..3206e38ad0090 100644 --- a/clang/test/CodeGenCXX/aarch64-arguments.cpp +++ b/clang/test/CodeGenCXX/aarch64-arguments.cpp @@ -1,5 +1,5 @@ // RUN: %clang_cc1 -triple arm64-none-linux -emit-llvm -w -o - %s | FileCheck -check-prefix=PCS %s -// PCS: define{{.*}} void @{{.*}}(i8 %a +// PCS: define{{.*}} void @{{.*}}(i64 %a.coerce) struct s0 {}; void f0(s0 a) {} diff --git a/clang/test/CodeGenCXX/arm64-darwinpcs.cpp b/clang/test/CodeGenCXX/arm64-darwinpcs.cpp index a0b0d9efdd4c4..ef0e2da3effac 100644 --- a/clang/test/CodeGenCXX/arm64-darwinpcs.cpp +++ b/clang/test/CodeGenCXX/arm64-darwinpcs.cpp @@ -7,7 +7,7 @@ void test_extensions(bool a, char b, short c) {} struct Empty {}; void test_empty(Empty e) {} -// CHECK: define{{.*}} void @_Z10test_empty5Empty(i8 +// CHECK: define{{.*}} void @_Z10test_empty5Empty(i64 %e.coerce) // CHECK-DARWIN: define{{.*}} void @_Z10test_empty5Empty() struct HFA { _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
