///
static Value *DecomposeSimpleLinearExpr(Value *Val, unsigned &Scale,
int &Offset) {
- assert(Val->getType()->isInteger(32) && "Unexpected allocation size type!");
+ assert(Val->getType()->isIntegerTy(32) && "Unexpected allocation size type!");
if (ConstantInt *CI = dyn_cast<ConstantInt>(Val)) {
Offset = CI->getZExtValue();
Scale = 0;
return Instruction::CastOps(Res);
}
-/// ValueRequiresCast - Return true if the cast from "V to Ty" actually results
-/// in any code being generated. It does not require codegen if V is simple
-/// enough or if the cast can be folded into other casts.
-bool InstCombiner::ValueRequiresCast(Instruction::CastOps opcode,const Value *V,
- const Type *Ty) {
+/// ShouldOptimizeCast - Return true if the cast from "V to Ty" actually
+/// results in any code being generated and is interesting to optimize out. If
+/// the cast can be eliminated by some other simple transformation, we prefer
+/// to do the simplification first.
+bool InstCombiner::ShouldOptimizeCast(Instruction::CastOps opc, const Value *V,
+ const Type *Ty) {
+ // Noop casts and casts of constants should be eliminated trivially.
if (V->getType() == Ty || isa<Constant>(V)) return false;
- // If this is another cast that can be eliminated, it isn't codegen either.
+ // If this is another cast that can be eliminated, we prefer to have it
+ // eliminated.
if (const CastInst *CI = dyn_cast<CastInst>(V))
- if (isEliminableCastPair(CI, opcode, Ty, TD))
+ if (isEliminableCastPair(CI, opc, Ty, TD))
return false;
+
+ // If this is a vector sext from a compare, then we don't want to break the
+ // idiom where each element of the extended vector is either zero or all ones.
+ if (opc == Instruction::SExt && isa<CmpInst>(V) && Ty->isVectorTy())
+ return false;
+
return true;
}
if (isa<PHINode>(Src)) {
// We don't do this if this would create a PHI node with an illegal type if
// it is currently legal.
- if (!isa<IntegerType>(Src->getType()) ||
- !isa<IntegerType>(CI.getType()) ||
+ if (!Src->getType()->isIntegerTy() ||
+ !CI.getType()->isIntegerTy() ||
ShouldChangeType(CI.getType(), Src->getType()))
if (Instruction *NV = FoldOpIntoPhi(CI))
return NV;
// type. Only do this if the dest type is a simple type, don't convert the
// expression tree to something weird like i93 unless the source is also
// strange.
- if ((isa<VectorType>(DestTy) || ShouldChangeType(SrcTy, DestTy)) &&
+ if ((DestTy->isVectorTy() || ShouldChangeType(SrcTy, DestTy)) &&
CanEvaluateTruncated(Src, DestTy)) {
// If this cast is a truncate, evaluting in a different type always
// eliminates the cast, so it is always a win.
DEBUG(dbgs() << "ICE: EvaluateInDifferentType converting expression type"
- " to avoid cast: " << CI);
+ " to avoid cast: " << CI << '\n');
Value *Res = EvaluateInDifferentType(Src, DestTy, false);
assert(Res->getType() == DestTy);
return ReplaceInstUsesWith(CI, Res);
// expression tree to something weird like i93 unless the source is also
// strange.
unsigned BitsToClear;
- if ((isa<VectorType>(DestTy) || ShouldChangeType(SrcTy, DestTy)) &&
+ if ((DestTy->isVectorTy() || ShouldChangeType(SrcTy, DestTy)) &&
CanEvaluateZExtd(Src, DestTy, BitsToClear)) {
assert(BitsToClear < SrcTy->getScalarSizeInBits() &&
"Unreasonable BitsToClear");
// zext (xor i1 X, true) to i32 --> xor (zext i1 X to i32), 1
Value *X;
- if (SrcI && SrcI->hasOneUse() && SrcI->getType()->isInteger(1) &&
+ if (SrcI && SrcI->hasOneUse() && SrcI->getType()->isIntegerTy(1) &&
match(SrcI, m_Not(m_Value(X))) &&
(!X->hasOneUse() || !isa<CmpInst>(X))) {
Value *New = Builder->CreateZExt(X, CI.getType());
Value *Src = CI.getOperand(0);
const Type *SrcTy = Src->getType(), *DestTy = CI.getType();
- // Canonicalize sign-extend from i1 to a select.
- if (Src->getType()->isInteger(1))
- return SelectInst::Create(Src,
- Constant::getAllOnesValue(CI.getType()),
- Constant::getNullValue(CI.getType()));
-
// Attempt to extend the entire input expression tree to the destination
// type. Only do this if the dest type is a simple type, don't convert the
// expression tree to something weird like i93 unless the source is also
// strange.
- if ((isa<VectorType>(DestTy) || ShouldChangeType(SrcTy, DestTy)) &&
+ if ((DestTy->isVectorTy() || ShouldChangeType(SrcTy, DestTy)) &&
CanEvaluateSExtd(Src, DestTy)) {
// Okay, we can transform this! Insert the new expression now.
DEBUG(dbgs() << "ICE: EvaluateInDifferentType converting expression type"
return BinaryOperator::CreateAShr(Res, ShAmt);
}
+
+ // (x <s 0) ? -1 : 0 -> ashr x, 31 -> all ones if signed
+ // (x >s -1) ? -1 : 0 -> ashr x, 31 -> all ones if not signed
+ {
+ ICmpInst::Predicate Pred; Value *CmpLHS; ConstantInt *CmpRHS;
+ if (match(Src, m_ICmp(Pred, m_Value(CmpLHS), m_ConstantInt(CmpRHS)))) {
+ // sext (x <s 0) to i32 --> x>>s31 true if signbit set.
+ // sext (x >s -1) to i32 --> (x>>s31)^-1 true if signbit clear.
+ if ((Pred == ICmpInst::ICMP_SLT && CmpRHS->isZero()) ||
+ (Pred == ICmpInst::ICMP_SGT && CmpRHS->isAllOnesValue())) {
+ Value *Sh = ConstantInt::get(CmpLHS->getType(),
+ CmpLHS->getType()->getScalarSizeInBits()-1);
+ Value *In = Builder->CreateAShr(CmpLHS, Sh, CmpLHS->getName()+".lobit");
+ if (In->getType() != CI.getType())
+ In = Builder->CreateIntCast(In, CI.getType(), true/*SExt*/, "tmp");
+
+ if (Pred == ICmpInst::ICMP_SGT)
+ In = Builder->CreateNot(In, In->getName()+".not");
+ return ReplaceInstUsesWith(CI, In);
+ }
+ }
+ }
+
+
// If the input is a shl/ashr pair of a same constant, then this is a sign
// extension from a smaller value. If we could trust arbitrary bitwidth
// integers, we could turn this into a truncate to the smaller bit and then
}
Instruction *InstCombiner::visitIntToPtr(IntToPtrInst &CI) {
- // If the source integer type is larger than the intptr_t type for
- // this target, do a trunc to the intptr_t type, then inttoptr of it. This
- // allows the trunc to be exposed to other transforms. Don't do this for
- // extending inttoptr's, because we don't know if the target sign or zero
- // extends to pointers.
- if (TD && CI.getOperand(0)->getType()->getScalarSizeInBits() >
- TD->getPointerSizeInBits()) {
- Value *P = Builder->CreateTrunc(CI.getOperand(0),
- TD->getIntPtrType(CI.getContext()), "tmp");
- return new IntToPtrInst(P, CI.getType());
+ // If the source integer type is not the intptr_t type for this target, do a
+ // trunc or zext to the intptr_t type, then inttoptr of it. This allows the
+ // cast to be exposed to other transforms.
+ if (TD) {
+ if (CI.getOperand(0)->getType()->getScalarSizeInBits() >
+ TD->getPointerSizeInBits()) {
+ Value *P = Builder->CreateTrunc(CI.getOperand(0),
+ TD->getIntPtrType(CI.getContext()), "tmp");
+ return new IntToPtrInst(P, CI.getType());
+ }
+ if (CI.getOperand(0)->getType()->getScalarSizeInBits() <
+ TD->getPointerSizeInBits()) {
+ Value *P = Builder->CreateZExt(CI.getOperand(0),
+ TD->getIntPtrType(CI.getContext()), "tmp");
+ return new IntToPtrInst(P, CI.getType());
+ }
}
if (Instruction *I = commonCastTransforms(CI))
}
Instruction *InstCombiner::visitPtrToInt(PtrToIntInst &CI) {
- // If the destination integer type is smaller than the intptr_t type for
- // this target, do a ptrtoint to intptr_t then do a trunc. This allows the
- // trunc to be exposed to other transforms. Don't do this for extending
- // ptrtoint's, because we don't know if the target sign or zero extends its
- // pointers.
- if (TD &&
- CI.getType()->getScalarSizeInBits() < TD->getPointerSizeInBits()) {
- Value *P = Builder->CreatePtrToInt(CI.getOperand(0),
- TD->getIntPtrType(CI.getContext()),
- "tmp");
- return new TruncInst(P, CI.getType());
+ // If the destination integer type is not the intptr_t type for this target,
+ // do a ptrtoint to intptr_t then do a trunc or zext. This allows the cast
+ // to be exposed to other transforms.
+ if (TD) {
+ if (CI.getType()->getScalarSizeInBits() < TD->getPointerSizeInBits()) {
+ Value *P = Builder->CreatePtrToInt(CI.getOperand(0),
+ TD->getIntPtrType(CI.getContext()),
+ "tmp");
+ return new TruncInst(P, CI.getType());
+ }
+ if (CI.getType()->getScalarSizeInBits() > TD->getPointerSizeInBits()) {
+ Value *P = Builder->CreatePtrToInt(CI.getOperand(0),
+ TD->getIntPtrType(CI.getContext()),
+ "tmp");
+ return new ZExtInst(P, CI.getType());
+ }
}
return commonPointerCastTransforms(CI);
}
+/// OptimizeVectorResize - This input value (which is known to have vector type)
+/// is being zero extended or truncated to the specified vector type. Try to
+/// replace it with a shuffle (and vector/vector bitcast) if possible.
+///
+/// The source and destination vector types may have different element types.
+static Instruction *OptimizeVectorResize(Value *InVal, const VectorType *DestTy,
+ InstCombiner &IC) {
+ // We can only do this optimization if the output is a multiple of the input
+ // element size, or the input is a multiple of the output element size.
+ // Convert the input type to have the same element type as the output.
+ const VectorType *SrcTy = cast<VectorType>(InVal->getType());
+
+ if (SrcTy->getElementType() != DestTy->getElementType()) {
+ // The input types don't need to be identical, but for now they must be the
+ // same size. There is no specific reason we couldn't handle things like
+ // <4 x i16> -> <4 x i32> by bitcasting to <2 x i32> but haven't gotten
+ // there yet.
+ if (SrcTy->getElementType()->getPrimitiveSizeInBits() !=
+ DestTy->getElementType()->getPrimitiveSizeInBits())
+ return 0;
+
+ SrcTy = VectorType::get(DestTy->getElementType(), SrcTy->getNumElements());
+ InVal = IC.Builder->CreateBitCast(InVal, SrcTy);
+ }
+
+ // Now that the element types match, get the shuffle mask and RHS of the
+ // shuffle to use, which depends on whether we're increasing or decreasing the
+ // size of the input.
+ SmallVector<Constant*, 16> ShuffleMask;
+ Value *V2;
+ const IntegerType *Int32Ty = Type::getInt32Ty(SrcTy->getContext());
+
+ if (SrcTy->getNumElements() > DestTy->getNumElements()) {
+ // If we're shrinking the number of elements, just shuffle in the low
+ // elements from the input and use undef as the second shuffle input.
+ V2 = UndefValue::get(SrcTy);
+ for (unsigned i = 0, e = DestTy->getNumElements(); i != e; ++i)
+ ShuffleMask.push_back(ConstantInt::get(Int32Ty, i));
+
+ } else {
+ // If we're increasing the number of elements, shuffle in all of the
+ // elements from InVal and fill the rest of the result elements with zeros
+ // from a constant zero.
+ V2 = Constant::getNullValue(SrcTy);
+ unsigned SrcElts = SrcTy->getNumElements();
+ for (unsigned i = 0, e = SrcElts; i != e; ++i)
+ ShuffleMask.push_back(ConstantInt::get(Int32Ty, i));
+
+ // The excess elements reference the first element of the zero input.
+ ShuffleMask.append(DestTy->getNumElements()-SrcElts,
+ ConstantInt::get(Int32Ty, SrcElts));
+ }
+
+ Constant *Mask = ConstantVector::get(ShuffleMask.data(), ShuffleMask.size());
+ return new ShuffleVectorInst(InVal, V2, Mask);
+}
+
+
Instruction *InstCombiner::visitBitCast(BitCastInst &CI) {
// If the operands are integer typed then apply the integer transforms,
// otherwise just apply the common ones.
Constant::getNullValue(Type::getInt32Ty(CI.getContext()));
unsigned NumZeros = 0;
while (SrcElTy != DstElTy &&
- isa<CompositeType>(SrcElTy) && !isa<PointerType>(SrcElTy) &&
+ isa<CompositeType>(SrcElTy) && !SrcElTy->isPointerTy() &&
SrcElTy->getNumContainedTypes() /* not "{}" */) {
SrcElTy = cast<CompositeType>(SrcElTy)->getTypeAtIndex(ZeroUInt);
++NumZeros;
}
if (const VectorType *DestVTy = dyn_cast<VectorType>(DestTy)) {
- if (DestVTy->getNumElements() == 1 && !isa<VectorType>(SrcTy)) {
+ if (DestVTy->getNumElements() == 1 && !SrcTy->isVectorTy()) {
Value *Elem = Builder->CreateBitCast(Src, DestVTy->getElementType());
return InsertElementInst::Create(UndefValue::get(DestTy), Elem,
Constant::getNullValue(Type::getInt32Ty(CI.getContext())));
// FIXME: Canonicalize bitcast(insertelement) -> insertelement(bitcast)
}
+
+ // If this is a cast from an integer to vector, check to see if the input
+ // is a trunc or zext of a bitcast from vector. If so, we can replace all
+ // the casts with a shuffle and (potentially) a bitcast.
+ if (isa<IntegerType>(SrcTy) && (isa<TruncInst>(Src) || isa<ZExtInst>(Src))){
+ CastInst *SrcCast = cast<CastInst>(Src);
+ if (BitCastInst *BCIn = dyn_cast<BitCastInst>(SrcCast->getOperand(0)))
+ if (isa<VectorType>(BCIn->getOperand(0)->getType()))
+ if (Instruction *I = OptimizeVectorResize(BCIn->getOperand(0),
+ cast<VectorType>(DestTy), *this))
+ return I;
+ }
}
if (const VectorType *SrcVTy = dyn_cast<VectorType>(SrcTy)) {
- if (SrcVTy->getNumElements() == 1 && !isa<VectorType>(DestTy)) {
+ if (SrcVTy->getNumElements() == 1 && !DestTy->isVectorTy()) {
Value *Elem =
Builder->CreateExtractElement(Src,
Constant::getNullValue(Type::getInt32Ty(CI.getContext())));
if (ShuffleVectorInst *SVI = dyn_cast<ShuffleVectorInst>(Src)) {
// Okay, we have (bitcast (shuffle ..)). Check to see if this is
- // a bitconvert to a vector with the same # elts.
- if (SVI->hasOneUse() && isa<VectorType>(DestTy) &&
+ // a bitcast to a vector with the same # elts.
+ if (SVI->hasOneUse() && DestTy->isVectorTy() &&
cast<VectorType>(DestTy)->getNumElements() ==
SVI->getType()->getNumElements() &&
SVI->getType()->getNumElements() ==
}
}
- if (isa<PointerType>(SrcTy))
+ if (SrcTy->isPointerTy())
return commonPointerCastTransforms(CI);
return commonCastTransforms(CI);
}