+static Value *SimplifyX86immshift(const IntrinsicInst &II,
+ InstCombiner::BuilderTy &Builder) {
+ bool LogicalShift = false;
+ bool ShiftLeft = false;
+
+ switch (II.getIntrinsicID()) {
+ default:
+ return nullptr;
+ case Intrinsic::x86_sse2_psra_d:
+ case Intrinsic::x86_sse2_psra_w:
+ case Intrinsic::x86_sse2_psrai_d:
+ case Intrinsic::x86_sse2_psrai_w:
+ case Intrinsic::x86_avx2_psra_d:
+ case Intrinsic::x86_avx2_psra_w:
+ case Intrinsic::x86_avx2_psrai_d:
+ case Intrinsic::x86_avx2_psrai_w:
+ LogicalShift = false; ShiftLeft = false;
+ break;
+ case Intrinsic::x86_sse2_psrl_d:
+ case Intrinsic::x86_sse2_psrl_q:
+ case Intrinsic::x86_sse2_psrl_w:
+ case Intrinsic::x86_sse2_psrli_d:
+ case Intrinsic::x86_sse2_psrli_q:
+ case Intrinsic::x86_sse2_psrli_w:
+ case Intrinsic::x86_avx2_psrl_d:
+ case Intrinsic::x86_avx2_psrl_q:
+ case Intrinsic::x86_avx2_psrl_w:
+ case Intrinsic::x86_avx2_psrli_d:
+ case Intrinsic::x86_avx2_psrli_q:
+ case Intrinsic::x86_avx2_psrli_w:
+ LogicalShift = true; ShiftLeft = false;
+ break;
+ case Intrinsic::x86_sse2_psll_d:
+ case Intrinsic::x86_sse2_psll_q:
+ case Intrinsic::x86_sse2_psll_w:
+ case Intrinsic::x86_sse2_pslli_d:
+ case Intrinsic::x86_sse2_pslli_q:
+ case Intrinsic::x86_sse2_pslli_w:
+ case Intrinsic::x86_avx2_psll_d:
+ case Intrinsic::x86_avx2_psll_q:
+ case Intrinsic::x86_avx2_psll_w:
+ case Intrinsic::x86_avx2_pslli_d:
+ case Intrinsic::x86_avx2_pslli_q:
+ case Intrinsic::x86_avx2_pslli_w:
+ LogicalShift = true; ShiftLeft = true;
+ break;
+ }
+ assert((LogicalShift || !ShiftLeft) && "Only logical shifts can shift left");
+
+ // Simplify if count is constant.
+ auto Arg1 = II.getArgOperand(1);
+ auto CAZ = dyn_cast<ConstantAggregateZero>(Arg1);
+ auto CDV = dyn_cast<ConstantDataVector>(Arg1);
+ auto CInt = dyn_cast<ConstantInt>(Arg1);
+ if (!CAZ && !CDV && !CInt)
+ return nullptr;
+
+ APInt Count(64, 0);
+ if (CDV) {
+ // SSE2/AVX2 uses all the first 64-bits of the 128-bit vector
+ // operand to compute the shift amount.
+ auto VT = cast<VectorType>(CDV->getType());
+ unsigned BitWidth = VT->getElementType()->getPrimitiveSizeInBits();
+ assert((64 % BitWidth) == 0 && "Unexpected packed shift size");
+ unsigned NumSubElts = 64 / BitWidth;
+
+ // Concatenate the sub-elements to create the 64-bit value.
+ for (unsigned i = 0; i != NumSubElts; ++i) {
+ unsigned SubEltIdx = (NumSubElts - 1) - i;
+ auto SubElt = cast<ConstantInt>(CDV->getElementAsConstant(SubEltIdx));
+ Count = Count.shl(BitWidth);
+ Count |= SubElt->getValue().zextOrTrunc(64);
+ }
+ }
+ else if (CInt)
+ Count = CInt->getValue();
+
+ auto Vec = II.getArgOperand(0);
+ auto VT = cast<VectorType>(Vec->getType());
+ auto SVT = VT->getElementType();
+ unsigned VWidth = VT->getNumElements();
+ unsigned BitWidth = SVT->getPrimitiveSizeInBits();
+
+ // If shift-by-zero then just return the original value.
+ if (Count == 0)
+ return Vec;
+
+ // Handle cases when Shift >= BitWidth.
+ if (Count.uge(BitWidth)) {
+ // If LogicalShift - just return zero.
+ if (LogicalShift)
+ return ConstantAggregateZero::get(VT);
+
+ // If ArithmeticShift - clamp Shift to (BitWidth - 1).
+ Count = APInt(64, BitWidth - 1);
+ }
+
+ // Get a constant vector of the same type as the first operand.
+ auto ShiftAmt = ConstantInt::get(SVT, Count.zextOrTrunc(BitWidth));
+ auto ShiftVec = Builder.CreateVectorSplat(VWidth, ShiftAmt);
+
+ if (ShiftLeft)
+ return Builder.CreateShl(Vec, ShiftVec);
+
+ if (LogicalShift)
+ return Builder.CreateLShr(Vec, ShiftVec);
+
+ return Builder.CreateAShr(Vec, ShiftVec);
+}
+
+static Value *SimplifyX86extend(const IntrinsicInst &II,
+ InstCombiner::BuilderTy &Builder,
+ bool SignExtend) {
+ VectorType *SrcTy = cast<VectorType>(II.getArgOperand(0)->getType());
+ VectorType *DstTy = cast<VectorType>(II.getType());
+ unsigned NumDstElts = DstTy->getNumElements();
+
+ // Extract a subvector of the first NumDstElts lanes and sign/zero extend.
+ SmallVector<int, 8> ShuffleMask;
+ for (int i = 0; i != (int)NumDstElts; ++i)
+ ShuffleMask.push_back(i);
+
+ Value *SV = Builder.CreateShuffleVector(II.getArgOperand(0),
+ UndefValue::get(SrcTy), ShuffleMask);
+ return SignExtend ? Builder.CreateSExt(SV, DstTy)
+ : Builder.CreateZExt(SV, DstTy);
+}
+