using namespace llvm;
/// CheapToScalarize - Return true if the value is cheaper to scalarize than it
-/// is to leave as a vector operation.
+/// is to leave as a vector operation. isConstant indicates whether we're
+/// extracting one known element. If false we're extracting a variable index.
static bool CheapToScalarize(Value *V, bool isConstant) {
- if (isa<ConstantAggregateZero>(V))
- return true;
- if (ConstantVector *C = dyn_cast<ConstantVector>(V)) {
+ if (Constant *C = dyn_cast<Constant>(V)) {
if (isConstant) return true;
- // If all elts are the same, we can extract.
- Constant *Op0 = C->getOperand(0);
- for (unsigned i = 1; i < C->getNumOperands(); ++i)
- if (C->getOperand(i) != Op0)
+
+ // If all elts are the same, we can extract it and use any of the values.
+ Constant *Op0 = C->getAggregateElement(0U);
+ for (unsigned i = 1, e = V->getType()->getVectorNumElements(); i != e; ++i)
+ if (C->getAggregateElement(i) != Op0)
return false;
return true;
}
return false;
}
-/// getShuffleMask - Read and decode a shufflevector mask.
-/// Turn undef elements into negative values.
-static std::vector<int> getShuffleMask(const ShuffleVectorInst *SVI) {
- unsigned NElts = SVI->getType()->getNumElements();
- if (isa<ConstantAggregateZero>(SVI->getOperand(2)))
- return std::vector<int>(NElts, 0);
- if (isa<UndefValue>(SVI->getOperand(2)))
- return std::vector<int>(NElts, -1);
-
- std::vector<int> Result;
- const ConstantVector *CP = cast<ConstantVector>(SVI->getOperand(2));
- for (User::const_op_iterator i = CP->op_begin(), e = CP->op_end(); i!=e; ++i)
- if (isa<UndefValue>(*i))
- Result.push_back(-1); // undef
- else
- Result.push_back(cast<ConstantInt>(*i)->getZExtValue());
- return Result;
-}
-
/// FindScalarElement - Given a vector and an element number, see if the scalar
/// value is already around as a register, for example if it were inserted then
/// extracted from the vector.
static Value *FindScalarElement(Value *V, unsigned EltNo) {
assert(V->getType()->isVectorTy() && "Not looking at a vector?");
- VectorType *PTy = cast<VectorType>(V->getType());
- unsigned Width = PTy->getNumElements();
+ VectorType *VTy = cast<VectorType>(V->getType());
+ unsigned Width = VTy->getNumElements();
if (EltNo >= Width) // Out of range access.
- return UndefValue::get(PTy->getElementType());
+ return UndefValue::get(VTy->getElementType());
- if (isa<UndefValue>(V))
- return UndefValue::get(PTy->getElementType());
- if (isa<ConstantAggregateZero>(V))
- return Constant::getNullValue(PTy->getElementType());
- if (ConstantVector *CP = dyn_cast<ConstantVector>(V))
- return CP->getOperand(EltNo);
+ if (Constant *C = dyn_cast<Constant>(V))
+ return C->getAggregateElement(EltNo);
if (InsertElementInst *III = dyn_cast<InsertElementInst>(V)) {
// If this is an insert to a variable element, we don't know what it is.
}
if (ShuffleVectorInst *SVI = dyn_cast<ShuffleVectorInst>(V)) {
- unsigned LHSWidth =
- cast<VectorType>(SVI->getOperand(0)->getType())->getNumElements();
- int InEl = getShuffleMask(SVI)[EltNo];
+ unsigned LHSWidth = SVI->getOperand(0)->getType()->getVectorNumElements();
+ int InEl = SVI->getMaskValue(EltNo);
if (InEl < 0)
- return UndefValue::get(PTy->getElementType());
+ return UndefValue::get(VTy->getElementType());
if (InEl < (int)LHSWidth)
return FindScalarElement(SVI->getOperand(0), InEl);
return FindScalarElement(SVI->getOperand(1), InEl - LHSWidth);
}
Instruction *InstCombiner::visitExtractElementInst(ExtractElementInst &EI) {
- // If vector val is undef, replace extract with scalar undef.
- if (isa<UndefValue>(EI.getOperand(0)))
- return ReplaceInstUsesWith(EI, UndefValue::get(EI.getType()));
-
- // If vector val is constant 0, replace extract with scalar 0.
- if (isa<ConstantAggregateZero>(EI.getOperand(0)))
- return ReplaceInstUsesWith(EI, Constant::getNullValue(EI.getType()));
-
- if (ConstantVector *C = dyn_cast<ConstantVector>(EI.getOperand(0))) {
- // If vector val is constant with all elements the same, replace EI with
- // that element. When the elements are not identical, we cannot replace yet
- // (we do that below, but only when the index is constant).
- Constant *op0 = C->getOperand(0);
- for (unsigned i = 1; i != C->getNumOperands(); ++i)
- if (C->getOperand(i) != op0) {
- op0 = 0;
- break;
- }
- if (op0)
- return ReplaceInstUsesWith(EI, op0);
- }
+ // If vector val is constant with all elements the same, replace EI with
+ // that element. We handle a known element # below.
+ if (Constant *C = dyn_cast<Constant>(EI.getOperand(0)))
+ if (CheapToScalarize(C, false))
+ return ReplaceInstUsesWith(EI, C->getAggregateElement(0U));
// If extracting a specified index from the vector, see if we can recursively
// find a previously computed scalar that was inserted into the vector.
// the same number of elements, see if we can find the source element from
// it. In this case, we will end up needing to bitcast the scalars.
if (BitCastInst *BCI = dyn_cast<BitCastInst>(EI.getOperand(0))) {
- if (VectorType *VT =
- dyn_cast<VectorType>(BCI->getOperand(0)->getType()))
+ if (VectorType *VT = dyn_cast<VectorType>(BCI->getOperand(0)->getType()))
if (VT->getNumElements() == VectorWidth)
if (Value *Elt = FindScalarElement(BCI->getOperand(0), IndexVal))
return new BitCastInst(Elt, EI.getType());
// If this is extracting an element from a shufflevector, figure out where
// it came from and extract from the appropriate input element instead.
if (ConstantInt *Elt = dyn_cast<ConstantInt>(EI.getOperand(1))) {
- int SrcIdx = getShuffleMask(SVI)[Elt->getZExtValue()];
+ int SrcIdx = SVI->getMaskValue(Elt->getZExtValue());
Value *Src;
unsigned LHSWidth =
- cast<VectorType>(SVI->getOperand(0)->getType())->getNumElements();
+ SVI->getOperand(0)->getType()->getVectorNumElements();
if (SrcIdx < 0)
return ReplaceInstUsesWith(EI, UndefValue::get(EI.getType()));
/// elements from either LHS or RHS, return the shuffle mask and true.
/// Otherwise, return false.
static bool CollectSingleShuffleElements(Value *V, Value *LHS, Value *RHS,
- std::vector<Constant*> &Mask) {
+ SmallVectorImpl<Constant*> &Mask) {
assert(V->getType() == LHS->getType() && V->getType() == RHS->getType() &&
"Invalid CollectSingleShuffleElements");
unsigned NumElts = cast<VectorType>(V->getType())->getNumElements();
/// CollectShuffleElements - We are building a shuffle of V, using RHS as the
/// RHS of the shuffle instruction, if it is not null. Return a shuffle mask
/// that computes V and the LHS value of the shuffle.
-static Value *CollectShuffleElements(Value *V, std::vector<Constant*> &Mask,
+static Value *CollectShuffleElements(Value *V, SmallVectorImpl<Constant*> &Mask,
Value *&RHS) {
assert(V->getType()->isVectorTy() &&
(RHS == 0 || V->getType() == RHS->getType()) &&
if (isa<UndefValue>(V)) {
Mask.assign(NumElts, UndefValue::get(Type::getInt32Ty(V->getContext())));
return V;
- } else if (isa<ConstantAggregateZero>(V)) {
+ }
+
+ if (isa<ConstantAggregateZero>(V)) {
Mask.assign(NumElts, ConstantInt::get(Type::getInt32Ty(V->getContext()),0));
return V;
- } else if (InsertElementInst *IEI = dyn_cast<InsertElementInst>(V)) {
+ }
+
+ if (InsertElementInst *IEI = dyn_cast<InsertElementInst>(V)) {
// If this is an insert of an extract from some other vector, include it.
Value *VecOp = IEI->getOperand(0);
Value *ScalarOp = IEI->getOperand(1);
// If this insertelement isn't used by some other insertelement, turn it
// (and any insertelements it points to), into one big shuffle.
if (!IE.hasOneUse() || !isa<InsertElementInst>(IE.use_back())) {
- std::vector<Constant*> Mask;
+ SmallVector<Constant*, 16> Mask;
Value *RHS = 0;
Value *LHS = CollectShuffleElements(&IE, Mask, RHS);
if (RHS == 0) RHS = UndefValue::get(LHS->getType());
Instruction *InstCombiner::visitShuffleVectorInst(ShuffleVectorInst &SVI) {
Value *LHS = SVI.getOperand(0);
Value *RHS = SVI.getOperand(1);
- std::vector<int> Mask = getShuffleMask(&SVI);
+ SmallVector<int, 16> Mask = SVI.getShuffleMask();
bool MadeChange = false;
unsigned VWidth = cast<VectorType>(SVI.getType())->getNumElements();
- if (VWidth != cast<VectorType>(LHS->getType())->getNumElements())
- return 0;
-
APInt UndefElts(VWidth, 0);
APInt AllOnesEltMask(APInt::getAllOnesValue(VWidth));
if (Value *V = SimplifyDemandedVectorElts(&SVI, AllOnesEltMask, UndefElts)) {
MadeChange = true;
}
+ unsigned LHSWidth = cast<VectorType>(LHS->getType())->getNumElements();
+
// Canonicalize shuffle(x ,x,mask) -> shuffle(x, undef,mask')
// Canonicalize shuffle(undef,x,mask) -> shuffle(x, undef,mask').
if (LHS == RHS || isa<UndefValue>(LHS)) {
if (isa<UndefValue>(LHS) && LHS == RHS) {
// shuffle(undef,undef,mask) -> undef.
- return ReplaceInstUsesWith(SVI, LHS);
+ Value* result = (VWidth == LHSWidth)
+ ? LHS : UndefValue::get(SVI.getType());
+ return ReplaceInstUsesWith(SVI, result);
}
// Remap any references to RHS to use LHS.
- std::vector<Constant*> Elts;
- for (unsigned i = 0, e = Mask.size(); i != e; ++i) {
- if (Mask[i] < 0)
+ SmallVector<Constant*, 16> Elts;
+ for (unsigned i = 0, e = LHSWidth; i != VWidth; ++i) {
+ if (Mask[i] < 0) {
Elts.push_back(UndefValue::get(Type::getInt32Ty(SVI.getContext())));
- else {
- if ((Mask[i] >= (int)e && isa<UndefValue>(RHS)) ||
- (Mask[i] < (int)e && isa<UndefValue>(LHS))) {
- Mask[i] = -1; // Turn into undef.
- Elts.push_back(UndefValue::get(Type::getInt32Ty(SVI.getContext())));
- } else {
- Mask[i] = Mask[i] % e; // Force to LHS.
- Elts.push_back(ConstantInt::get(Type::getInt32Ty(SVI.getContext()),
- Mask[i]));
- }
+ continue;
+ }
+
+ if ((Mask[i] >= (int)e && isa<UndefValue>(RHS)) ||
+ (Mask[i] < (int)e && isa<UndefValue>(LHS))) {
+ Mask[i] = -1; // Turn into undef.
+ Elts.push_back(UndefValue::get(Type::getInt32Ty(SVI.getContext())));
+ } else {
+ Mask[i] = Mask[i] % e; // Force to LHS.
+ Elts.push_back(ConstantInt::get(Type::getInt32Ty(SVI.getContext()),
+ Mask[i]));
}
}
SVI.setOperand(0, SVI.getOperand(1));
MadeChange = true;
}
- // Analyze the shuffle, are the LHS or RHS and identity shuffles?
- bool isLHSID = true, isRHSID = true;
+ if (VWidth == LHSWidth) {
+ // Analyze the shuffle, are the LHS or RHS and identity shuffles?
+ bool isLHSID = true, isRHSID = true;
- for (unsigned i = 0, e = Mask.size(); i != e; ++i) {
- if (Mask[i] < 0) continue; // Ignore undef values.
- // Is this an identity shuffle of the LHS value?
- isLHSID &= (Mask[i] == (int)i);
+ for (unsigned i = 0, e = Mask.size(); i != e; ++i) {
+ if (Mask[i] < 0) continue; // Ignore undef values.
+ // Is this an identity shuffle of the LHS value?
+ isLHSID &= (Mask[i] == (int)i);
- // Is this an identity shuffle of the RHS value?
- isRHSID &= (Mask[i]-e == i);
- }
+ // Is this an identity shuffle of the RHS value?
+ isRHSID &= (Mask[i]-e == i);
+ }
- // Eliminate identity shuffles.
- if (isLHSID) return ReplaceInstUsesWith(SVI, LHS);
- if (isRHSID) return ReplaceInstUsesWith(SVI, RHS);
+ // Eliminate identity shuffles.
+ if (isLHSID) return ReplaceInstUsesWith(SVI, LHS);
+ if (isRHSID) return ReplaceInstUsesWith(SVI, RHS);
+ }
// If the LHS is a shufflevector itself, see if we can combine it with this
- // one without producing an unusual shuffle. Here we are really conservative:
+ // one without producing an unusual shuffle.
+ // Cases that might be simplified:
+ // 1.
+ // x1=shuffle(v1,v2,mask1)
+ // x=shuffle(x1,undef,mask)
+ // ==>
+ // x=shuffle(v1,undef,newMask)
+ // newMask[i] = (mask[i] < x1.size()) ? mask1[mask[i]] : -1
+ // 2.
+ // x1=shuffle(v1,undef,mask1)
+ // x=shuffle(x1,x2,mask)
+ // where v1.size() == mask1.size()
+ // ==>
+ // x=shuffle(v1,x2,newMask)
+ // newMask[i] = (mask[i] < x1.size()) ? mask1[mask[i]] : mask[i]
+ // 3.
+ // x2=shuffle(v2,undef,mask2)
+ // x=shuffle(x1,x2,mask)
+ // where v2.size() == mask2.size()
+ // ==>
+ // x=shuffle(x1,v2,newMask)
+ // newMask[i] = (mask[i] < x1.size())
+ // ? mask[i] : mask2[mask[i]-x1.size()]+x1.size()
+ // 4.
+ // x1=shuffle(v1,undef,mask1)
+ // x2=shuffle(v2,undef,mask2)
+ // x=shuffle(x1,x2,mask)
+ // where v1.size() == v2.size()
+ // ==>
+ // x=shuffle(v1,v2,newMask)
+ // newMask[i] = (mask[i] < x1.size())
+ // ? mask1[mask[i]] : mask2[mask[i]-x1.size()]+v1.size()
+ //
+ // Here we are really conservative:
// we are absolutely afraid of producing a shuffle mask not in the input
// program, because the code gen may not be smart enough to turn a merged
// shuffle into two specific shuffles: it may produce worse code. As such,
// we only merge two shuffles if the result is either a splat or one of the
- // two input shuffle masks. In this case, merging the shuffles just removes
+ // input shuffle masks. In this case, merging the shuffles just removes
// one instruction, which we know is safe. This is good for things like
- // turning: (splat(splat)) -> splat.
- if (ShuffleVectorInst *LHSSVI = dyn_cast<ShuffleVectorInst>(LHS)) {
+ // turning: (splat(splat)) -> splat, or
+ // merge(V[0..n], V[n+1..2n]) -> V[0..2n]
+ ShuffleVectorInst* LHSShuffle = dyn_cast<ShuffleVectorInst>(LHS);
+ ShuffleVectorInst* RHSShuffle = dyn_cast<ShuffleVectorInst>(RHS);
+ if (LHSShuffle)
+ if (!isa<UndefValue>(LHSShuffle->getOperand(1)) && !isa<UndefValue>(RHS))
+ LHSShuffle = NULL;
+ if (RHSShuffle)
+ if (!isa<UndefValue>(RHSShuffle->getOperand(1)))
+ RHSShuffle = NULL;
+ if (!LHSShuffle && !RHSShuffle)
+ return MadeChange ? &SVI : 0;
+
+ Value* LHSOp0 = NULL;
+ Value* LHSOp1 = NULL;
+ Value* RHSOp0 = NULL;
+ unsigned LHSOp0Width = 0;
+ unsigned RHSOp0Width = 0;
+ if (LHSShuffle) {
+ LHSOp0 = LHSShuffle->getOperand(0);
+ LHSOp1 = LHSShuffle->getOperand(1);
+ LHSOp0Width = cast<VectorType>(LHSOp0->getType())->getNumElements();
+ }
+ if (RHSShuffle) {
+ RHSOp0 = RHSShuffle->getOperand(0);
+ RHSOp0Width = cast<VectorType>(RHSOp0->getType())->getNumElements();
+ }
+ Value* newLHS = LHS;
+ Value* newRHS = RHS;
+ if (LHSShuffle) {
+ // case 1
if (isa<UndefValue>(RHS)) {
- std::vector<int> LHSMask = getShuffleMask(LHSSVI);
-
- if (LHSMask.size() == Mask.size()) {
- std::vector<int> NewMask;
- bool isSplat = true;
- int SplatElt = -1; // undef
- for (unsigned i = 0, e = Mask.size(); i != e; ++i) {
- int MaskElt;
- if (Mask[i] < 0 || Mask[i] >= (int)e)
- MaskElt = -1; // undef
- else
- MaskElt = LHSMask[Mask[i]];
- // Check if this could still be a splat.
- if (MaskElt >= 0) {
- if (SplatElt >=0 && SplatElt != MaskElt)
- isSplat = false;
- SplatElt = MaskElt;
- }
- NewMask.push_back(MaskElt);
- }
+ newLHS = LHSOp0;
+ newRHS = LHSOp1;
+ }
+ // case 2 or 4
+ else if (LHSOp0Width == LHSWidth) {
+ newLHS = LHSOp0;
+ }
+ }
+ // case 3 or 4
+ if (RHSShuffle && RHSOp0Width == LHSWidth) {
+ newRHS = RHSOp0;
+ }
+ // case 4
+ if (LHSOp0 == RHSOp0) {
+ newLHS = LHSOp0;
+ newRHS = NULL;
+ }
- // If the result mask is equal to the src shuffle or this
- // shuffle mask, do the replacement.
- if (isSplat || NewMask == LHSMask || NewMask == Mask) {
- std::vector<Constant*> Elts;
- Type *Int32Ty = Type::getInt32Ty(SVI.getContext());
- for (unsigned i = 0, e = NewMask.size(); i != e; ++i) {
- if (NewMask[i] < 0) {
- Elts.push_back(UndefValue::get(Int32Ty));
- } else {
- Elts.push_back(ConstantInt::get(Int32Ty, NewMask[i]));
- }
- }
- return new ShuffleVectorInst(LHSSVI->getOperand(0),
- LHSSVI->getOperand(1),
- ConstantVector::get(Elts));
+ if (newLHS == LHS && newRHS == RHS)
+ return MadeChange ? &SVI : 0;
+
+ SmallVector<int, 16> LHSMask;
+ SmallVector<int, 16> RHSMask;
+ if (newLHS != LHS)
+ LHSMask = LHSShuffle->getShuffleMask();
+ if (RHSShuffle && newRHS != RHS)
+ RHSMask = RHSShuffle->getShuffleMask();
+
+ unsigned newLHSWidth = (newLHS != LHS) ? LHSOp0Width : LHSWidth;
+ SmallVector<int, 16> newMask;
+ bool isSplat = true;
+ int SplatElt = -1;
+ // Create a new mask for the new ShuffleVectorInst so that the new
+ // ShuffleVectorInst is equivalent to the original one.
+ for (unsigned i = 0; i < VWidth; ++i) {
+ int eltMask;
+ if (Mask[i] == -1) {
+ // This element is an undef value.
+ eltMask = -1;
+ } else if (Mask[i] < (int)LHSWidth) {
+ // This element is from left hand side vector operand.
+ //
+ // If LHS is going to be replaced (case 1, 2, or 4), calculate the
+ // new mask value for the element.
+ if (newLHS != LHS) {
+ eltMask = LHSMask[Mask[i]];
+ // If the value selected is an undef value, explicitly specify it
+ // with a -1 mask value.
+ if (eltMask >= (int)LHSOp0Width && isa<UndefValue>(LHSOp1))
+ eltMask = -1;
+ }
+ else
+ eltMask = Mask[i];
+ } else {
+ // This element is from right hand side vector operand
+ //
+ // If the value selected is an undef value, explicitly specify it
+ // with a -1 mask value. (case 1)
+ if (isa<UndefValue>(RHS))
+ eltMask = -1;
+ // If RHS is going to be replaced (case 3 or 4), calculate the
+ // new mask value for the element.
+ else if (newRHS != RHS) {
+ eltMask = RHSMask[Mask[i]-LHSWidth];
+ // If the value selected is an undef value, explicitly specify it
+ // with a -1 mask value.
+ if (eltMask >= (int)RHSOp0Width) {
+ assert(isa<UndefValue>(RHSShuffle->getOperand(1))
+ && "should have been check above");
+ eltMask = -1;
}
}
+ else
+ eltMask = Mask[i]-LHSWidth;
+
+ // If LHS's width is changed, shift the mask value accordingly.
+ // If newRHS == NULL, i.e. LHSOp0 == RHSOp0, we want to remap any
+ // references to RHSOp0 to LHSOp0, so we don't need to shift the mask.
+ if (eltMask >= 0 && newRHS != NULL)
+ eltMask += newLHSWidth;
+ }
+
+ // Check if this could still be a splat.
+ if (eltMask >= 0) {
+ if (SplatElt >= 0 && SplatElt != eltMask)
+ isSplat = false;
+ SplatElt = eltMask;
+ }
+
+ newMask.push_back(eltMask);
+ }
+
+ // If the result mask is equal to one of the original shuffle masks,
+ // or is a splat, do the replacement.
+ if (isSplat || newMask == LHSMask || newMask == RHSMask || newMask == Mask) {
+ SmallVector<Constant*, 16> Elts;
+ Type *Int32Ty = Type::getInt32Ty(SVI.getContext());
+ for (unsigned i = 0, e = newMask.size(); i != e; ++i) {
+ if (newMask[i] < 0) {
+ Elts.push_back(UndefValue::get(Int32Ty));
+ } else {
+ Elts.push_back(ConstantInt::get(Int32Ty, newMask[i]));
+ }
}
+ if (newRHS == NULL)
+ newRHS = UndefValue::get(newLHS->getType());
+ return new ShuffleVectorInst(newLHS, newRHS, ConstantVector::get(Elts));
}
return MadeChange ? &SVI : 0;
projects / oota-llvm.git / blobdiff