https://github.com/CoTinker updated https://github.com/llvm/llvm-project/pull/86388
>From 54f75d7068d0acf336d6d1e61bcf800ff52cc310 Mon Sep 17 00:00:00 2001 From: Longsheng Mou <moulongsh...@huawei.com> Date: Sat, 23 Mar 2024 17:53:58 +0800 Subject: [PATCH] [X86_32] fix 0 sized struct case in vaarg. struct SuperEmpty { struct{ int a[0];} b;}; Such 0 sized structs in c++ mode can not be ignored in i386 for that c++ fields are never empty.But when EmitVAArg, its size is 0, so that va_list not increase.Maybe we can ignore this kind of arguments. --- clang/lib/CodeGen/Targets/X86.cpp | 4 ++++ clang/test/CodeGenCXX/regparm.cpp | 2 +- clang/test/CodeGenCXX/x86_32-vaarg.cpp | 22 ++++++++++++++++++++++ 3 files changed, 27 insertions(+), 1 deletion(-) diff --git a/clang/lib/CodeGen/Targets/X86.cpp b/clang/lib/CodeGen/Targets/X86.cpp index 16d52bee3490b..26ff4e4ac0a3b 100644 --- a/clang/lib/CodeGen/Targets/X86.cpp +++ b/clang/lib/CodeGen/Targets/X86.cpp @@ -795,6 +795,10 @@ ABIArgInfo X86_32ABIInfo::classifyArgumentType(QualType Ty, CCState &State, if (!IsWin32StructABI && isEmptyRecord(getContext(), Ty, true)) return ABIArgInfo::getIgnore(); + // Ignore 0 sized structs. + if (TI.Width == 0) + return ABIArgInfo::getIgnore(); + llvm::LLVMContext &LLVMContext = getVMContext(); llvm::IntegerType *Int32 = llvm::Type::getInt32Ty(LLVMContext); bool NeedsPadding = false; diff --git a/clang/test/CodeGenCXX/regparm.cpp b/clang/test/CodeGenCXX/regparm.cpp index 1fd471c2d0727..b9735485db8de 100644 --- a/clang/test/CodeGenCXX/regparm.cpp +++ b/clang/test/CodeGenCXX/regparm.cpp @@ -32,7 +32,7 @@ struct S3 { } a; }; __attribute((regparm(2))) void foo4(S3 a, int b); -// CHECK: declare void @_Z4foo42S3i(ptr noundef byval(%struct.S3) align 4, i32 inreg noundef) +// CHECK: declare void @_Z4foo42S3i(i32 inreg noundef) void bar3(S3 a, int b) { foo4(a, b); } diff --git a/clang/test/CodeGenCXX/x86_32-vaarg.cpp b/clang/test/CodeGenCXX/x86_32-vaarg.cpp index a3f2791484362..90665652a0286 100644 --- a/clang/test/CodeGenCXX/x86_32-vaarg.cpp +++ b/clang/test/CodeGenCXX/x86_32-vaarg.cpp @@ -18,3 +18,25 @@ empty empty_record_test(int z, ...) { __builtin_va_start(list, z); return __builtin_va_arg(list, empty); } + +typedef struct { + struct { + int a[0]; + } b; +} SortOfEmpty; + +// CHECK-LABEL: @_Z18test_sort_of_emptyiz( +// CHECK-NEXT: entry: +// CHECK-NEXT: [[RESULT_PTR:%.*]] = alloca ptr, align 4 +// CHECK-NEXT: [[Z_ADDR:%.*]] = alloca i32, align 4 +// CHECK-NEXT: [[LIST:%.*]] = alloca ptr, align 4 +// CHECK-NEXT: store ptr [[AGG_RESULT:%.*]], ptr [[RESULT_PTR]], align 4 +// CHECK-NEXT: store i32 [[Z:%.*]], ptr [[Z_ADDR]], align 4 +// CHECK-NEXT: call void @llvm.va_start.p0(ptr [[LIST]]) +// CHECK-NEXT: ret void +// +SortOfEmpty test_sort_of_empty(int z, ...) { + __builtin_va_list list; + __builtin_va_start(list, z); + return __builtin_va_arg(list, SortOfEmpty); +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits