[llvm] r225597 - X86: Properly decode shuffle masks when the constant pool type is weird
David Majnemer
david.majnemer at gmail.com
Sat Jan 10 21:08:57 PST 2015
Author: majnemer
Date: Sat Jan 10 23:08:57 2015
New Revision: 225597
URL: http://llvm.org/viewvc/llvm-project?rev=225597&view=rev
Log:
X86: Properly decode shuffle masks when the constant pool type is weird
It's possible for the constant pool entry for the shuffle mask to come
from a completely different operation. This occurs when Constants have
the same bit pattern but have different types.
Make DecodePSHUFBMask tolerant of types which, after a bitcast, are
appropriately sized vector types.
This fixes PR22188.
Modified:
llvm/trunk/lib/Target/X86/Utils/X86ShuffleDecode.cpp
llvm/trunk/lib/Target/X86/Utils/X86ShuffleDecode.h
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
llvm/trunk/lib/Target/X86/X86MCInstLower.cpp
llvm/trunk/test/CodeGen/X86/pshufb-mask-comments.ll
Modified: llvm/trunk/lib/Target/X86/Utils/X86ShuffleDecode.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/Utils/X86ShuffleDecode.cpp?rev=225597&r1=225596&r2=225597&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/Utils/X86ShuffleDecode.cpp (original)
+++ llvm/trunk/lib/Target/X86/Utils/X86ShuffleDecode.cpp Sat Jan 10 23:08:57 2015
@@ -13,7 +13,10 @@
//===----------------------------------------------------------------------===//
#include "X86ShuffleDecode.h"
+#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/InstrTypes.h"
#include "llvm/CodeGen/MachineValueType.h"
//===----------------------------------------------------------------------===//
@@ -253,57 +256,64 @@ void DecodeVPERM2X128Mask(MVT VT, unsign
}
}
-void DecodePSHUFBMask(const Constant *C, SmallVectorImpl<int> &ShuffleMask) {
+void DecodePSHUFBMask(const Constant *C, const DataLayout *TD,
+ SmallVectorImpl<int> &ShuffleMask) {
Type *MaskTy = C->getType();
- assert(MaskTy->isVectorTy() && "Expected a vector constant mask!");
- assert(MaskTy->getVectorElementType()->isIntegerTy(8) &&
- "Expected i8 constant mask elements!");
- int NumElements = MaskTy->getVectorNumElements();
+ // It is not an error for the PSHUFB mask to not be a vector of i8 because the
+ // constant pool uniques constants by their bit representation.
+ // e.g. the following take up the same space in the constant pool:
+ // i128 -170141183420855150465331762880109871104
+ //
+ // <2 x i64> <i64 -9223372034707292160, i64 -9223372034707292160>
+ //
+ // <4 x i32> <i32 -2147483648, i32 -2147483648, i32 -2147483648, i32
+ // -2147483648>
+
+ unsigned MaskTySize = MaskTy->getPrimitiveSizeInBits();
+
+ VectorType *DestTy = nullptr;
+ if (MaskTySize == 128)
+ DestTy = VectorType::get(Type::getInt8Ty(MaskTy->getContext()), 16);
+ else if (MaskTySize == 256)
+ DestTy = VectorType::get(Type::getInt8Ty(MaskTy->getContext()), 32);
+
// FIXME: Add support for AVX-512.
- assert((NumElements == 16 || NumElements == 32) &&
- "Only 128-bit and 256-bit vectors supported!");
+ if (!DestTy)
+ return;
+
+ if (DestTy != MaskTy) {
+ if (!CastInst::castIsValid(Instruction::BitCast, const_cast<Constant *>(C),
+ DestTy))
+ return;
+
+ C = ConstantFoldInstOperands(Instruction::BitCast, DestTy,
+ const_cast<Constant *>(C), TD);
+ MaskTy = DestTy;
+ }
+
+ int NumElements = MaskTy->getVectorNumElements();
ShuffleMask.reserve(NumElements);
- if (auto *CDS = dyn_cast<ConstantDataSequential>(C)) {
- assert((unsigned)NumElements == CDS->getNumElements() &&
- "Constant mask has a different number of elements!");
-
- for (int i = 0; i < NumElements; ++i) {
- // For AVX vectors with 32 bytes the base of the shuffle is the 16-byte
- // lane of the vector we're inside.
- int Base = i < 16 ? 0 : 16;
- uint64_t Element = CDS->getElementAsInteger(i);
- // If the high bit (7) of the byte is set, the element is zeroed.
- if (Element & (1 << 7))
- ShuffleMask.push_back(SM_SentinelZero);
- else {
- // Only the least significant 4 bits of the byte are used.
- int Index = Base + (Element & 0xf);
- ShuffleMask.push_back(Index);
- }
- }
- } else if (auto *CV = dyn_cast<ConstantVector>(C)) {
- assert((unsigned)NumElements == CV->getNumOperands() &&
- "Constant mask has a different number of elements!");
-
- for (int i = 0; i < NumElements; ++i) {
- // For AVX vectors with 32 bytes the base of the shuffle is the 16-byte
- // lane of the vector we're inside.
- int Base = i < 16 ? 0 : 16;
- Constant *COp = CV->getOperand(i);
- if (isa<UndefValue>(COp)) {
- ShuffleMask.push_back(SM_SentinelUndef);
- continue;
- }
- uint64_t Element = cast<ConstantInt>(COp)->getZExtValue();
- // If the high bit (7) of the byte is set, the element is zeroed.
- if (Element & (1 << 7))
- ShuffleMask.push_back(SM_SentinelZero);
- else {
- // Only the least significant 4 bits of the byte are used.
- int Index = Base + (Element & 0xf);
- ShuffleMask.push_back(Index);
- }
+ for (int i = 0; i < NumElements; ++i) {
+ // For AVX vectors with 32 bytes the base of the shuffle is the 16-byte
+ // lane of the vector we're inside.
+ int Base = i < 16 ? 0 : 16;
+ Constant *COp = C->getAggregateElement(i);
+ if (!COp) {
+ ShuffleMask.clear();
+ return;
+ } else if (isa<UndefValue>(COp)) {
+ ShuffleMask.push_back(SM_SentinelUndef);
+ continue;
+ }
+ uint64_t Element = cast<ConstantInt>(COp)->getZExtValue();
+ // If the high bit (7) of the byte is set, the element is zeroed.
+ if (Element & (1 << 7))
+ ShuffleMask.push_back(SM_SentinelZero);
+ else {
+ // Only the least significant 4 bits of the byte are used.
+ int Index = Base + (Element & 0xf);
+ ShuffleMask.push_back(Index);
}
}
}
Modified: llvm/trunk/lib/Target/X86/Utils/X86ShuffleDecode.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/Utils/X86ShuffleDecode.h?rev=225597&r1=225596&r2=225597&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/Utils/X86ShuffleDecode.h (original)
+++ llvm/trunk/lib/Target/X86/Utils/X86ShuffleDecode.h Sat Jan 10 23:08:57 2015
@@ -24,6 +24,7 @@
namespace llvm {
class Constant;
+class DataLayout;
class MVT;
enum { SM_SentinelUndef = -1, SM_SentinelZero = -2 };
@@ -68,7 +69,8 @@ void DecodeUNPCKHMask(MVT VT, SmallVecto
void DecodeUNPCKLMask(MVT VT, SmallVectorImpl<int> &ShuffleMask);
/// \brief Decode a PSHUFB mask from an IR-level vector constant.
-void DecodePSHUFBMask(const Constant *C, SmallVectorImpl<int> &ShuffleMask);
+void DecodePSHUFBMask(const Constant *C, const DataLayout *TD,
+ SmallVectorImpl<int> &ShuffleMask);
/// \brief Decode a PSHUFB mask from a raw array of constants such as from
/// BUILD_VECTOR.
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=225597&r1=225596&r2=225597&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Sat Jan 10 23:08:57 2015
@@ -5365,7 +5365,7 @@ static SDValue getShuffleVectorZeroOrUnd
/// IsUnary to true if only uses one source. Note that this will set IsUnary for
/// shuffles which use a single input multiple times, and in those cases it will
/// adjust the mask to only have indices within that single input.
-static bool getTargetShuffleMask(SDNode *N, MVT VT,
+static bool getTargetShuffleMask(SDNode *N, MVT VT, const DataLayout *TD,
SmallVectorImpl<int> &Mask, bool &IsUnary) {
unsigned NumElems = VT.getVectorNumElements();
SDValue ImmN;
@@ -5472,13 +5472,7 @@ static bool getTargetShuffleMask(SDNode
return false;
if (auto *C = dyn_cast<Constant>(MaskCP->getConstVal())) {
- // FIXME: Support AVX-512 here.
- Type *Ty = C->getType();
- if (!Ty->isVectorTy() || (Ty->getVectorNumElements() != 16 &&
- Ty->getVectorNumElements() != 32))
- return false;
-
- DecodePSHUFBMask(C, Mask);
+ DecodePSHUFBMask(C, TD, Mask);
break;
}
@@ -5541,6 +5535,7 @@ static SDValue getShuffleScalarElt(SDNod
SDValue V = SDValue(N, 0);
EVT VT = V.getValueType();
unsigned Opcode = V.getOpcode();
+ const DataLayout *TD = DAG.getSubtarget().getDataLayout();
// Recurse into ISD::VECTOR_SHUFFLE node to find scalars.
if (const ShuffleVectorSDNode *SV = dyn_cast<ShuffleVectorSDNode>(N)) {
@@ -5562,7 +5557,7 @@ static SDValue getShuffleScalarElt(SDNod
SmallVector<int, 16> ShuffleMask;
bool IsUnary;
- if (!getTargetShuffleMask(N, ShufVT, ShuffleMask, IsUnary))
+ if (!getTargetShuffleMask(N, ShufVT, TD, ShuffleMask, IsUnary))
return SDValue();
int Elt = ShuffleMask[Index];
@@ -22117,7 +22112,8 @@ static bool combineX86ShufflesRecursivel
return false;
SmallVector<int, 16> OpMask;
bool IsUnary;
- bool HaveMask = getTargetShuffleMask(Op.getNode(), VT, OpMask, IsUnary);
+ bool HaveMask = getTargetShuffleMask(
+ Op.getNode(), VT, Subtarget->getDataLayout(), OpMask, IsUnary);
// We only can combine unary shuffles which we can decode the mask for.
if (!HaveMask || !IsUnary)
return false;
@@ -22208,10 +22204,12 @@ static bool combineX86ShufflesRecursivel
///
/// This is a very minor wrapper around getTargetShuffleMask to easy forming v4
/// PSHUF-style masks that can be reused with such instructions.
-static SmallVector<int, 4> getPSHUFShuffleMask(SDValue N) {
+static SmallVector<int, 4> getPSHUFShuffleMask(SDValue N,
+ const DataLayout *TD) {
SmallVector<int, 4> Mask;
bool IsUnary;
- bool HaveMask = getTargetShuffleMask(N.getNode(), N.getSimpleValueType(), Mask, IsUnary);
+ bool HaveMask = getTargetShuffleMask(N.getNode(), N.getSimpleValueType(), TD,
+ Mask, IsUnary);
(void)HaveMask;
assert(HaveMask);
@@ -22243,6 +22241,7 @@ combineRedundantDWordShuffle(SDValue N,
assert(N.getOpcode() == X86ISD::PSHUFD &&
"Called with something other than an x86 128-bit half shuffle!");
SDLoc DL(N);
+ const DataLayout *TD = DAG.getSubtarget().getDataLayout();
// Walk up a single-use chain looking for a combinable shuffle. Keep a stack
// of the shuffles in the chain so that we can form a fresh chain to replace
@@ -22328,7 +22327,7 @@ combineRedundantDWordShuffle(SDValue N,
return SDValue();
// Merge this node's mask and our incoming mask.
- SmallVector<int, 4> VMask = getPSHUFShuffleMask(V);
+ SmallVector<int, 4> VMask = getPSHUFShuffleMask(V, TD);
for (int &M : Mask)
M = VMask[M];
V = DAG.getNode(V.getOpcode(), DL, V.getValueType(), V.getOperand(0),
@@ -22377,6 +22376,7 @@ static bool combineRedundantHalfShuffle(
"Called with something other than an x86 128-bit half shuffle!");
SDLoc DL(N);
unsigned CombineOpcode = N.getOpcode();
+ const DataLayout *TD = DAG.getSubtarget().getDataLayout();
// Walk up a single-use chain looking for a combinable shuffle.
SDValue V = N.getOperand(0);
@@ -22415,7 +22415,7 @@ static bool combineRedundantHalfShuffle(
// Merge this node's mask and our incoming mask (adjusted to account for all
// the pshufd instructions encountered).
- SmallVector<int, 4> VMask = getPSHUFShuffleMask(V);
+ SmallVector<int, 4> VMask = getPSHUFShuffleMask(V, TD);
for (int &M : Mask)
M = VMask[M];
V = DAG.getNode(V.getOpcode(), DL, MVT::v8i16, V.getOperand(0),
@@ -22437,13 +22437,14 @@ static SDValue PerformTargetShuffleCombi
const X86Subtarget *Subtarget) {
SDLoc DL(N);
MVT VT = N.getSimpleValueType();
+ const DataLayout *TD = Subtarget->getDataLayout();
SmallVector<int, 4> Mask;
switch (N.getOpcode()) {
case X86ISD::PSHUFD:
case X86ISD::PSHUFLW:
case X86ISD::PSHUFHW:
- Mask = getPSHUFShuffleMask(N);
+ Mask = getPSHUFShuffleMask(N, TD);
assert(Mask.size() == 4);
break;
default:
@@ -22495,8 +22496,8 @@ static SDValue PerformTargetShuffleCombi
while (D.getOpcode() == ISD::BITCAST && D.hasOneUse())
D = D.getOperand(0);
if (D.getOpcode() == X86ISD::PSHUFD && D.hasOneUse()) {
- SmallVector<int, 4> VMask = getPSHUFShuffleMask(V);
- SmallVector<int, 4> DMask = getPSHUFShuffleMask(D);
+ SmallVector<int, 4> VMask = getPSHUFShuffleMask(V, TD);
+ SmallVector<int, 4> DMask = getPSHUFShuffleMask(D, TD);
int NOffset = N.getOpcode() == X86ISD::PSHUFLW ? 0 : 4;
int VOffset = V.getOpcode() == X86ISD::PSHUFLW ? 0 : 4;
int WordMask[8];
@@ -22749,9 +22750,10 @@ static SDValue XFormVExtractWithShuffleI
if (!InVec.hasOneUse())
return SDValue();
+ const DataLayout *TD = DAG.getSubtarget().getDataLayout();
SmallVector<int, 16> ShuffleMask;
bool UnaryShuffle;
- if (!getTargetShuffleMask(InVec.getNode(), CurrentVT.getSimpleVT(),
+ if (!getTargetShuffleMask(InVec.getNode(), CurrentVT.getSimpleVT(), TD,
ShuffleMask, UnaryShuffle))
return SDValue();
Modified: llvm/trunk/lib/Target/X86/X86MCInstLower.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86MCInstLower.cpp?rev=225597&r1=225596&r2=225597&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86MCInstLower.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86MCInstLower.cpp Sat Jan 10 23:08:57 2015
@@ -1161,7 +1161,7 @@ void X86AsmPrinter::EmitInstruction(cons
if (auto *C = getConstantFromPool(*MI, MaskOp)) {
SmallVector<int, 16> Mask;
- DecodePSHUFBMask(C, Mask);
+ DecodePSHUFBMask(C, TM.getSubtargetImpl()->getDataLayout(), Mask);
if (!Mask.empty())
OutStreamer.AddComment(getShuffleComment(DstOp, SrcOp, Mask));
}
Modified: llvm/trunk/test/CodeGen/X86/pshufb-mask-comments.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/pshufb-mask-comments.ll?rev=225597&r1=225596&r2=225597&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/pshufb-mask-comments.ll (original)
+++ llvm/trunk/test/CodeGen/X86/pshufb-mask-comments.ll Sat Jan 10 23:08:57 2015
@@ -27,4 +27,14 @@ define <16 x i8> @test3(<16 x i8> %V) {
ret <16 x i8> %1
}
+; Test that we won't crash when the constant was reused for another instruction.
+
+define <16 x i8> @test4(<2 x i64>* %V) {
+; CHECK-LABEL: test4
+; CHECK: pshufb {{.*}}# xmm0 = xmm0[8,9,10,11,12,13,14,15,0,1,2,3,4,5,6,7]
+ store <2 x i64> <i64 1084818905618843912, i64 506097522914230528>, <2 x i64>* %V, align 16
+ %1 = tail call <16 x i8> @llvm.x86.ssse3.pshuf.b.128(<16 x i8> undef, <16 x i8> <i8 8, i8 9, i8 10, i8 11, i8 12, i8 13, i8 14, i8 15, i8 0, i8 1, i8 2, i8 3, i8 4, i8 5, i8 6, i8 7>)
+ ret <16 x i8> %1
+}
+
declare <16 x i8> @llvm.x86.ssse3.pshuf.b.128(<16 x i8>, <16 x i8>) nounwind readnone
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