Author: Dávid Bolvanský Date: 2021-04-23T14:05:57+02:00 New Revision: 2cae7025c1d9e83d971f670c9a66497a8c1094ec
URL: https://github.com/llvm/llvm-project/commit/2cae7025c1d9e83d971f670c9a66497a8c1094ec DIFF: https://github.com/llvm/llvm-project/commit/2cae7025c1d9e83d971f670c9a66497a8c1094ec.diff LOG: Reland "[Clang] Propagate guaranteed alignment for malloc and others" This relands commit 6914a0ed2b30924b188968e59a83efa07ac5fe57. Crash in InstCombine was fixed. Added: clang/test/CodeGen/alloc-fns-alignment.c Modified: clang/include/clang/Basic/TargetInfo.h clang/lib/CodeGen/CGCall.cpp Removed: ################################################################################ diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h index 3bcaaceb63d8e..449c026639b90 100644 --- a/clang/include/clang/Basic/TargetInfo.h +++ b/clang/include/clang/Basic/TargetInfo.h @@ -612,8 +612,8 @@ class TargetInfo : public virtual TransferrableTargetInfo, } /// Return the largest alignment for which a suitably-sized allocation with - /// '::operator new(size_t)' is guaranteed to produce a correctly-aligned - /// pointer. + /// '::operator new(size_t)' or 'malloc' is guaranteed to produce a + /// correctly-aligned pointer. unsigned getNewAlign() const { return NewAlign ? NewAlign : std::max(LongDoubleAlign, LongLongAlign); } diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp index 366c83eeb8e89..6c77f1889fb52 100644 --- a/clang/lib/CodeGen/CGCall.cpp +++ b/clang/lib/CodeGen/CGCall.cpp @@ -2048,6 +2048,24 @@ void CodeGenModule::ConstructAttributeList( // allows it to work on indirect virtual function calls. if (AttrOnCallSite && TargetDecl->hasAttr<NoMergeAttr>()) FuncAttrs.addAttribute(llvm::Attribute::NoMerge); + + // Add known guaranteed alignment for allocation functions. + if (unsigned BuiltinID = Fn->getBuiltinID()) { + switch (BuiltinID) { + case Builtin::BIaligned_alloc: + case Builtin::BIcalloc: + case Builtin::BImalloc: + case Builtin::BImemalign: + case Builtin::BIrealloc: + case Builtin::BIstrdup: + case Builtin::BIstrndup: + RetAttrs.addAlignmentAttr(Context.getTargetInfo().getNewAlign() / + Context.getTargetInfo().getCharWidth()); + break; + default: + break; + } + } } // 'const', 'pure' and 'noalias' attributed functions are also nounwind. diff --git a/clang/test/CodeGen/alloc-fns-alignment.c b/clang/test/CodeGen/alloc-fns-alignment.c new file mode 100644 index 0000000000000..d2f9b467196a7 --- /dev/null +++ b/clang/test/CodeGen/alloc-fns-alignment.c @@ -0,0 +1,35 @@ +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN16 +// RUN: %clang_cc1 -triple x86_64-windows-msvc -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN16 +// RUN: %clang_cc1 -triple i386-apple-darwin -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN16 +// RUN: %clang_cc1 -triple i386-unknown-linux-gnu -emit-llvm < %s | FileCheck %s --check-prefix=ALIGN8 +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-builtin-malloc -emit-llvm < %s | FileCheck %s --check-prefix=NOBUILTIN-MALLOC +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-builtin-calloc -emit-llvm < %s | FileCheck %s --check-prefix=NOBUILTIN-CALLOC +// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fno-builtin-realloc -emit-llvm < %s | FileCheck %s --check-prefix=NOBUILTIN-REALLOC + +typedef __SIZE_TYPE__ size_t; + +void *malloc(size_t); +void *calloc(size_t, size_t); +void *realloc(void *, size_t); + +void *malloc_test(size_t n) { + return malloc(n); +} + +void *calloc_test(size_t n) { + return calloc(1, n); +} + +void *raalloc_test(void *p, size_t n) { + return realloc(p, n); +} + +// ALIGN16: align 16 i8* @malloc +// ALIGN16: align 16 i8* @calloc +// ALIGN16: align 16 i8* @realloc +// ALIGN8: align 8 i8* @malloc +// ALIGN8: align 8 i8* @calloc +// ALIGN8: align 8 i8* @realloc +// NOBUILTIN-MALLOC: declare i8* @malloc +// NOBUILTIN-CALLOC: declare i8* @calloc +// NOBUILTIN-REALLOC: declare i8* @realloc _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits