if (!Origin) {
Origin = OpOrigin;
} else {
- Value *FlatShadow = MSV->convertToShadowTyNoVec(OpShadow, IRB);
- Value *Cond = IRB.CreateICmpNE(FlatShadow,
- MSV->getCleanShadow(FlatShadow));
- Origin = IRB.CreateSelect(Cond, OpOrigin, Origin);
+ Constant *ConstOrigin = dyn_cast<Constant>(OpOrigin);
+ // No point in adding something that might result in 0 origin value.
+ if (!ConstOrigin || !ConstOrigin->isNullValue()) {
+ Value *FlatShadow = MSV->convertToShadowTyNoVec(OpShadow, IRB);
+ Value *Cond =
+ IRB.CreateICmpNE(FlatShadow, MSV->getCleanShadow(FlatShadow));
+ Origin = IRB.CreateSelect(Cond, OpOrigin, Origin);
+ }
}
}
return *this;
SC.Done(&I);
}
+ // \brief Handle multiplication by constant.
+ //
+ // Handle a special case of multiplication by constant that may have one or
+ // more zeros in the lower bits. This makes corresponding number of lower bits
+ // of the result zero as well. We model it by shifting the other operand
+ // shadow left by the required number of bits. Effectively, we transform
+ // (X * (A * 2**B)) to ((X << B) * A) and instrument (X << B) as (Sx << B).
+ // We use multiplication by 2**N instead of shift to cover the case of
+ // multiplication by 0, which may occur in some elements of a vector operand.
+ void handleMulByConstant(BinaryOperator &I, Constant *ConstArg,
+ Value *OtherArg) {
+ Constant *ShadowMul;
+ Type *Ty = ConstArg->getType();
+ if (Ty->isVectorTy()) {
+ unsigned NumElements = Ty->getVectorNumElements();
+ Type *EltTy = Ty->getSequentialElementType();
+ SmallVector<Constant *, 16> Elements;
+ for (unsigned Idx = 0; Idx < NumElements; ++Idx) {
+ ConstantInt *Elt =
+ dyn_cast<ConstantInt>(ConstArg->getAggregateElement(Idx));
+ APInt V = Elt->getValue();
+ APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros();
+ Elements.push_back(ConstantInt::get(EltTy, V2));
+ }
+ ShadowMul = ConstantVector::get(Elements);
+ } else {
+ ConstantInt *Elt = dyn_cast<ConstantInt>(ConstArg);
+ APInt V = Elt->getValue();
+ APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros();
+ ShadowMul = ConstantInt::get(Elt->getType(), V2);
+ }
+
+ IRBuilder<> IRB(&I);
+ setShadow(&I,
+ IRB.CreateMul(getShadow(OtherArg), ShadowMul, "msprop_mul_cst"));
+ setOrigin(&I, getOrigin(OtherArg));
+ }
+
+ void visitMul(BinaryOperator &I) {
+ Constant *constOp0 = dyn_cast<Constant>(I.getOperand(0));
+ Constant *constOp1 = dyn_cast<Constant>(I.getOperand(1));
+ if (constOp0 && !constOp1)
+ handleMulByConstant(I, constOp0, I.getOperand(1));
+ else if (constOp1 && !constOp0)
+ handleMulByConstant(I, constOp1, I.getOperand(0));
+ else
+ handleShadowOr(I);
+ }
+
void visitFAdd(BinaryOperator &I) { handleShadowOr(I); }
void visitFSub(BinaryOperator &I) { handleShadowOr(I); }
void visitFMul(BinaryOperator &I) { handleShadowOr(I); }
void visitAdd(BinaryOperator &I) { handleShadowOr(I); }
void visitSub(BinaryOperator &I) { handleShadowOr(I); }
void visitXor(BinaryOperator &I) { handleShadowOr(I); }
- void visitMul(BinaryOperator &I) { handleShadowOr(I); }
void handleDiv(Instruction &I) {
IRBuilder<> IRB(&I);
}
}
- // \brief Instrument vector shift instrinsic.
+ // \brief Instrument vector pack instrinsic.
//
// This function instruments intrinsics like x86_mmx_packsswb, that
- // packs elements of 2 input vectors into half as much bits with saturation.
+ // packs elements of 2 input vectors into half as many bits with saturation.
// Shadow is propagated with the signed variant of the same intrinsic applied
// to sext(Sa != zeroinitializer), sext(Sb != zeroinitializer).
// EltSizeInBits is used only for x86mmx arguments.
setOriginForNaryOp(I);
}
+ // \brief Instrument sum-of-absolute-differencies intrinsic.
+ void handleVectorSadIntrinsic(IntrinsicInst &I) {
+ const unsigned SignificantBitsPerResultElement = 16;
+ bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy();
+ Type *ResTy = isX86_MMX ? IntegerType::get(*MS.C, 64) : I.getType();
+ unsigned ZeroBitsPerResultElement =
+ ResTy->getScalarSizeInBits() - SignificantBitsPerResultElement;
+
+ IRBuilder<> IRB(&I);
+ Value *S = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
+ S = IRB.CreateBitCast(S, ResTy);
+ S = IRB.CreateSExt(IRB.CreateICmpNE(S, Constant::getNullValue(ResTy)),
+ ResTy);
+ S = IRB.CreateLShr(S, ZeroBitsPerResultElement);
+ S = IRB.CreateBitCast(S, getShadowTy(&I));
+ setShadow(&I, S);
+ setOriginForNaryOp(I);
+ }
+
+ // \brief Instrument multiply-add intrinsic.
+ void handleVectorPmaddIntrinsic(IntrinsicInst &I,
+ unsigned EltSizeInBits = 0) {
+ bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy();
+ Type *ResTy = isX86_MMX ? getMMXVectorTy(EltSizeInBits * 2) : I.getType();
+ IRBuilder<> IRB(&I);
+ Value *S = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
+ S = IRB.CreateBitCast(S, ResTy);
+ S = IRB.CreateSExt(IRB.CreateICmpNE(S, Constant::getNullValue(ResTy)),
+ ResTy);
+ S = IRB.CreateBitCast(S, getShadowTy(&I));
+ setShadow(&I, S);
+ setOriginForNaryOp(I);
+ }
+
void visitIntrinsicInst(IntrinsicInst &I) {
switch (I.getIntrinsicID()) {
case llvm::Intrinsic::bswap:
handleVectorPackIntrinsic(I, 32);
break;
+ case llvm::Intrinsic::x86_mmx_psad_bw:
+ case llvm::Intrinsic::x86_sse2_psad_bw:
+ case llvm::Intrinsic::x86_avx2_psad_bw:
+ handleVectorSadIntrinsic(I);
+ break;
+
+ case llvm::Intrinsic::x86_sse2_pmadd_wd:
+ case llvm::Intrinsic::x86_avx2_pmadd_wd:
+ case llvm::Intrinsic::x86_ssse3_pmadd_ub_sw_128:
+ case llvm::Intrinsic::x86_avx2_pmadd_ub_sw:
+ handleVectorPmaddIntrinsic(I);
+ break;
+
+ case llvm::Intrinsic::x86_ssse3_pmadd_ub_sw:
+ handleVectorPmaddIntrinsic(I, 8);
+ break;
+
+ case llvm::Intrinsic::x86_mmx_pmadd_wd:
+ handleVectorPmaddIntrinsic(I, 16);
+ break;
+
default:
if (!handleUnknownIntrinsic(I))
visitInstruction(I);