From 88207c9ca218486b93ae7df14e9764cd0c2c3383 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 21 Apr 2009 17:59:23 +0000 Subject: don't bother emitting a zero byte memset at all. We used to get them in cases like this: typedef struct { short instance; char name[0]; } ATTR_LIST_ENTRY2; void test() { ATTR_LIST_ENTRY2 X = (ATTR_LIST_ENTRY2) { .instance = 7, }; } While it is safe to emit them, it is pretty silly. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69687 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/CodeGenFunction.cpp | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'lib/CodeGen/CodeGenFunction.cpp') diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp index 45c7d0aa27..082beb8de8 100644 --- a/lib/CodeGen/CodeGenFunction.cpp +++ b/lib/CodeGen/CodeGenFunction.cpp @@ -396,8 +396,7 @@ unsigned CodeGenFunction::GetIDForAddrOfLabel(const LabelStmt *L) { return LabelIDs.insert(std::make_pair(L, LabelIDs.size())).first->second; } -void CodeGenFunction::EmitMemSetToZero(llvm::Value *DestPtr, QualType Ty) -{ +void CodeGenFunction::EmitMemSetToZero(llvm::Value *DestPtr, QualType Ty) { const llvm::Type *BP = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); if (DestPtr->getType() != BP) DestPtr = Builder.CreateBitCast(DestPtr, BP, "tmp"); @@ -405,6 +404,10 @@ void CodeGenFunction::EmitMemSetToZero(llvm::Value *DestPtr, QualType Ty) // Get size and alignment info for this aggregate. std::pair TypeInfo = getContext().getTypeInfo(Ty); + // Don't bother emitting a zero-byte memset. + if (TypeInfo.first == 0) + return; + // FIXME: Handle variable sized types. const llvm::Type *IntPtr = llvm::IntegerType::get(LLVMPointerWidth); -- cgit v1.2.3-18-g5258