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Eliminate some literal 8s from EmitNullInitialization() by converting 

variables to CharUnits. No change in functionality intended.

llvm-svn: 130001
This commit is contained in:
Ken Dyck 2011-04-22 17:51:05 +00:00
parent 7a6f2a358a
commit c5c416f7db
1 changed files with 9 additions and 7 deletions
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16
clang/lib/CodeGen/CodeGenFunction.cpp
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@ -654,15 +654,16 @@ CodeGenFunction::EmitNullInitialization(llvm::Value *DestPtr, QualType Ty) {
DestPtr = Builder.CreateBitCast(DestPtr, BP, "tmp");
// Get size and alignment info for this aggregate.
std::pair<uint64_t, unsigned> TypeInfo = getContext().getTypeInfo(Ty);
uint64_t Size = TypeInfo.first / 8;
unsigned Align = TypeInfo.second / 8;
std::pair<CharUnits, CharUnits> TypeInfo =
getContext().getTypeInfoInChars(Ty);
CharUnits Size = TypeInfo.first;
CharUnits Align = TypeInfo.second;
llvm::Value *SizeVal;
const VariableArrayType *vla;
// Don't bother emitting a zero-byte memset.
if (Size == 0) {
if (Size.isZero()) {
// But note that getTypeInfo returns 0 for a VLA.
if (const VariableArrayType *vlaType =
dyn_cast_or_null<VariableArrayType>(
@ -673,7 +674,7 @@ CodeGenFunction::EmitNullInitialization(llvm::Value *DestPtr, QualType Ty) {
return;
}
} else {
SizeVal = llvm::ConstantInt::get(IntPtrTy, Size);
SizeVal = llvm::ConstantInt::get(IntPtrTy, Size.getQuantity());
vla = 0;
}
@ -698,14 +699,15 @@ CodeGenFunction::EmitNullInitialization(llvm::Value *DestPtr, QualType Ty) {
if (vla) return emitNonZeroVLAInit(*this, Ty, DestPtr, SrcPtr, SizeVal);
// Get and call the appropriate llvm.memcpy overload.
Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, Align, false);
Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, Align.getQuantity(), false);
return;
}
// Otherwise, just memset the whole thing to zero. This is legal
// because in LLVM, all default initializers (other than the ones we just
// handled above) are guaranteed to have a bit pattern of all zeros.
Builder.CreateMemSet(DestPtr, Builder.getInt8(0), SizeVal, Align, false);
Builder.CreateMemSet(DestPtr, Builder.getInt8(0), SizeVal,
Align.getQuantity(), false);
}
llvm::BlockAddress *CodeGenFunction::GetAddrOfLabel(const LabelDecl *L) {