IRGen: Emit an inline implementation of __builtin_wmemcmp on MSVCRT platforms.
The MSVC runtime library does not provide a definition of wmemcmp,
so we need an inline implementation.
Differential Revision: https://reviews.llvm.org/D42441
llvm-svn: 323362
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 67d331e..b4ae779 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1741,6 +1741,63 @@
Builder.CreateMemSet(Dest, ByteVal, SizeVal, false);
return RValue::get(Dest.getPointer());
}
+ case Builtin::BI__builtin_wmemcmp: {
+ // The MSVC runtime library does not provide a definition of wmemcmp, so we
+ // need an inline implementation.
+ if (!getTarget().getTriple().isOSMSVCRT())
+ break;
+
+ llvm::Type *WCharTy = ConvertType(getContext().WCharTy);
+
+ Value *Dst = EmitScalarExpr(E->getArg(0));
+ Value *Src = EmitScalarExpr(E->getArg(1));
+ Value *Size = EmitScalarExpr(E->getArg(2));
+
+ BasicBlock *Entry = Builder.GetInsertBlock();
+ BasicBlock *CmpGT = createBasicBlock("wmemcmp.gt");
+ BasicBlock *CmpLT = createBasicBlock("wmemcmp.lt");
+ BasicBlock *Next = createBasicBlock("wmemcmp.next");
+ BasicBlock *Exit = createBasicBlock("wmemcmp.exit");
+ Value *SizeEq0 = Builder.CreateICmpEQ(Size, ConstantInt::get(SizeTy, 0));
+ Builder.CreateCondBr(SizeEq0, Exit, CmpGT);
+
+ EmitBlock(CmpGT);
+ PHINode *DstPhi = Builder.CreatePHI(Dst->getType(), 2);
+ DstPhi->addIncoming(Dst, Entry);
+ PHINode *SrcPhi = Builder.CreatePHI(Src->getType(), 2);
+ SrcPhi->addIncoming(Src, Entry);
+ PHINode *SizePhi = Builder.CreatePHI(SizeTy, 2);
+ SizePhi->addIncoming(Size, Entry);
+ CharUnits WCharAlign =
+ getContext().getTypeAlignInChars(getContext().WCharTy);
+ Value *DstCh = Builder.CreateAlignedLoad(WCharTy, DstPhi, WCharAlign);
+ Value *SrcCh = Builder.CreateAlignedLoad(WCharTy, SrcPhi, WCharAlign);
+ Value *DstGtSrc = Builder.CreateICmpUGT(DstCh, SrcCh);
+ Builder.CreateCondBr(DstGtSrc, Exit, CmpLT);
+
+ EmitBlock(CmpLT);
+ Value *DstLtSrc = Builder.CreateICmpULT(DstCh, SrcCh);
+ Builder.CreateCondBr(DstLtSrc, Exit, Next);
+
+ EmitBlock(Next);
+ Value *NextDst = Builder.CreateConstInBoundsGEP1_32(WCharTy, DstPhi, 1);
+ Value *NextSrc = Builder.CreateConstInBoundsGEP1_32(WCharTy, SrcPhi, 1);
+ Value *NextSize = Builder.CreateSub(SizePhi, ConstantInt::get(SizeTy, 1));
+ Value *NextSizeEq0 =
+ Builder.CreateICmpEQ(NextSize, ConstantInt::get(SizeTy, 0));
+ Builder.CreateCondBr(NextSizeEq0, Exit, CmpGT);
+ DstPhi->addIncoming(NextDst, Next);
+ SrcPhi->addIncoming(NextSrc, Next);
+ SizePhi->addIncoming(NextSize, Next);
+
+ EmitBlock(Exit);
+ PHINode *Ret = Builder.CreatePHI(IntTy, 4);
+ Ret->addIncoming(ConstantInt::get(IntTy, 0), Entry);
+ Ret->addIncoming(ConstantInt::get(IntTy, 1), CmpGT);
+ Ret->addIncoming(ConstantInt::get(IntTy, -1), CmpLT);
+ Ret->addIncoming(ConstantInt::get(IntTy, 0), Next);
+ return RValue::get(Ret);
+ }
case Builtin::BI__builtin_dwarf_cfa: {
// The offset in bytes from the first argument to the CFA.
//