case Instruction::Trunc:
// trunc(trunc(x)) -> trunc(x)
return true;
+ case Instruction::ZExt:
+ case Instruction::SExt:
+ // trunc(ext(x)) -> ext(x) if the source type is smaller than the new dest
+ // trunc(ext(x)) -> trunc(x) if the source type is larger than the new dest
+ return true;
case Instruction::Select: {
SelectInst *SI = cast<SelectInst>(I);
return CanEvaluateTruncated(SI->getTrueValue(), Ty) &&
Value *Zero = Constant::getNullValue(Src->getType());
return new ICmpInst(ICmpInst::ICMP_NE, Src, Zero);
}
+
+ // Transform trunc(lshr (zext A), Cst) to eliminate one type conversion.
+ Value *A = 0; ConstantInt *Cst = 0;
+ if (match(Src, m_LShr(m_ZExt(m_Value(A)), m_ConstantInt(Cst))) &&
+ Src->hasOneUse()) {
+ // We have three types to worry about here, the type of A, the source of
+ // the truncate (MidSize), and the destination of the truncate. We know that
+ // ASize < MidSize and MidSize > ResultSize, but don't know the relation
+ // between ASize and ResultSize.
+ unsigned ASize = A->getType()->getPrimitiveSizeInBits();
+
+ // If the shift amount is larger than the size of A, then the result is
+ // known to be zero because all the input bits got shifted out.
+ if (Cst->getZExtValue() >= ASize)
+ return ReplaceInstUsesWith(CI, Constant::getNullValue(CI.getType()));
+
+ // Since we're doing an lshr and a zero extend, and know that the shift
+ // amount is smaller than ASize, it is always safe to do the shift in A's
+ // type, then zero extend or truncate to the result.
+ Value *Shift = Builder->CreateLShr(A, Cst->getZExtValue());
+ Shift->takeName(Src);
+ return CastInst::CreateIntegerCast(Shift, CI.getType(), false);
+ }
return 0;
}
if (CI.getType() == In->getType())
return ReplaceInstUsesWith(CI, In);
- else
- return CastInst::CreateIntegerCast(In, CI.getType(), false/*ZExt*/);
+ return CastInst::CreateIntegerCast(In, CI.getType(), false/*ZExt*/);
}
}
}
}
}
}
-
-
+
+ // vector (x <s 0) ? -1 : 0 -> ashr x, 31 -> all ones if signed.
+ if (const VectorType *VTy = dyn_cast<VectorType>(DestTy)) {
+ ICmpInst::Predicate Pred; Value *CmpLHS;
+ if (match(Src, m_ICmp(Pred, m_Value(CmpLHS), m_Zero()))) {
+ if (Pred == ICmpInst::ICMP_SLT && CmpLHS->getType() == DestTy) {
+ const Type *EltTy = VTy->getElementType();
+
+ // splat the shift constant to a cosntant vector
+ Constant *Sh = ConstantInt::get(EltTy, EltTy->getScalarSizeInBits()-1);
+ std::vector<Constant *> Elts(VTy->getNumElements(), Sh);
+ Constant *VSh = ConstantVector::get(Elts);
+
+ Value *In = Builder->CreateAShr(CmpLHS, VSh,CmpLHS->getName()+".lobit");
+ 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
Arg->getOperand(0)->getType()->isFloatTy()) {
Function *Callee = Call->getCalledFunction();
Module *M = CI.getParent()->getParent()->getParent();
- Constant* SqrtfFunc = M->getOrInsertFunction("sqrtf",
+ Constant *SqrtfFunc = M->getOrInsertFunction("sqrtf",
Callee->getAttributes(),
Builder->getFloatTy(),
Builder->getFloatTy(),
CallInst *ret = CallInst::Create(SqrtfFunc, Arg->getOperand(0),
"sqrtfcall");
ret->setAttributes(Callee->getAttributes());
+
+
+ // Remove the old Call. With -fmath-errno, it won't get marked readnone.
+ Call->replaceAllUsesWith(UndefValue::get(Call->getType()));
+ EraseInstFromFunction(*Call);
return ret;
}
}
return new ShuffleVectorInst(InVal, V2, Mask);
}
+static bool isMultipleOfTypeSize(unsigned Value, const Type *Ty) {
+ return Value % Ty->getPrimitiveSizeInBits() == 0;
+}
+
+static unsigned getTypeSizeIndex(unsigned Value, const Type *Ty) {
+ return Value / Ty->getPrimitiveSizeInBits();
+}
+
+/// CollectInsertionElements - V is a value which is inserted into a vector of
+/// VecEltTy. Look through the value to see if we can decompose it into
+/// insertions into the vector. See the example in the comment for
+/// OptimizeIntegerToVectorInsertions for the pattern this handles.
+/// The type of V is always a non-zero multiple of VecEltTy's size.
+///
+/// This returns false if the pattern can't be matched or true if it can,
+/// filling in Elements with the elements found here.
+static bool CollectInsertionElements(Value *V, unsigned ElementIndex,
+ SmallVectorImpl<Value*> &Elements,
+ const Type *VecEltTy) {
+ // Undef values never contribute useful bits to the result.
+ if (isa<UndefValue>(V)) return true;
+
+ // If we got down to a value of the right type, we win, try inserting into the
+ // right element.
+ if (V->getType() == VecEltTy) {
+ // Inserting null doesn't actually insert any elements.
+ if (Constant *C = dyn_cast<Constant>(V))
+ if (C->isNullValue())
+ return true;
+
+ // Fail if multiple elements are inserted into this slot.
+ if (ElementIndex >= Elements.size() || Elements[ElementIndex] != 0)
+ return false;
+
+ Elements[ElementIndex] = V;
+ return true;
+ }
+
+ if (Constant *C = dyn_cast<Constant>(V)) {
+ // Figure out the # elements this provides, and bitcast it or slice it up
+ // as required.
+ unsigned NumElts = getTypeSizeIndex(C->getType()->getPrimitiveSizeInBits(),
+ VecEltTy);
+ // If the constant is the size of a vector element, we just need to bitcast
+ // it to the right type so it gets properly inserted.
+ if (NumElts == 1)
+ return CollectInsertionElements(ConstantExpr::getBitCast(C, VecEltTy),
+ ElementIndex, Elements, VecEltTy);
+
+ // Okay, this is a constant that covers multiple elements. Slice it up into
+ // pieces and insert each element-sized piece into the vector.
+ if (!isa<IntegerType>(C->getType()))
+ C = ConstantExpr::getBitCast(C, IntegerType::get(V->getContext(),
+ C->getType()->getPrimitiveSizeInBits()));
+ unsigned ElementSize = VecEltTy->getPrimitiveSizeInBits();
+ const Type *ElementIntTy = IntegerType::get(C->getContext(), ElementSize);
+
+ for (unsigned i = 0; i != NumElts; ++i) {
+ Constant *Piece = ConstantExpr::getLShr(C, ConstantInt::get(C->getType(),
+ i*ElementSize));
+ Piece = ConstantExpr::getTrunc(Piece, ElementIntTy);
+ if (!CollectInsertionElements(Piece, ElementIndex+i, Elements, VecEltTy))
+ return false;
+ }
+ return true;
+ }
+
+ if (!V->hasOneUse()) return false;
+
+ Instruction *I = dyn_cast<Instruction>(V);
+ if (I == 0) return false;
+ switch (I->getOpcode()) {
+ default: return false; // Unhandled case.
+ case Instruction::BitCast:
+ return CollectInsertionElements(I->getOperand(0), ElementIndex,
+ Elements, VecEltTy);
+ case Instruction::ZExt:
+ if (!isMultipleOfTypeSize(
+ I->getOperand(0)->getType()->getPrimitiveSizeInBits(),
+ VecEltTy))
+ return false;
+ return CollectInsertionElements(I->getOperand(0), ElementIndex,
+ Elements, VecEltTy);
+ case Instruction::Or:
+ return CollectInsertionElements(I->getOperand(0), ElementIndex,
+ Elements, VecEltTy) &&
+ CollectInsertionElements(I->getOperand(1), ElementIndex,
+ Elements, VecEltTy);
+ case Instruction::Shl: {
+ // Must be shifting by a constant that is a multiple of the element size.
+ ConstantInt *CI = dyn_cast<ConstantInt>(I->getOperand(1));
+ if (CI == 0) return false;
+ if (!isMultipleOfTypeSize(CI->getZExtValue(), VecEltTy)) return false;
+ unsigned IndexShift = getTypeSizeIndex(CI->getZExtValue(), VecEltTy);
+
+ return CollectInsertionElements(I->getOperand(0), ElementIndex+IndexShift,
+ Elements, VecEltTy);
+ }
+
+ }
+}
+
+
+/// OptimizeIntegerToVectorInsertions - If the input is an 'or' instruction, we
+/// may be doing shifts and ors to assemble the elements of the vector manually.
+/// Try to rip the code out and replace it with insertelements. This is to
+/// optimize code like this:
+///
+/// %tmp37 = bitcast float %inc to i32
+/// %tmp38 = zext i32 %tmp37 to i64
+/// %tmp31 = bitcast float %inc5 to i32
+/// %tmp32 = zext i32 %tmp31 to i64
+/// %tmp33 = shl i64 %tmp32, 32
+/// %ins35 = or i64 %tmp33, %tmp38
+/// %tmp43 = bitcast i64 %ins35 to <2 x float>
+///
+/// Into two insertelements that do "buildvector{%inc, %inc5}".
+static Value *OptimizeIntegerToVectorInsertions(BitCastInst &CI,
+ InstCombiner &IC) {
+ const VectorType *DestVecTy = cast<VectorType>(CI.getType());
+ Value *IntInput = CI.getOperand(0);
+
+ SmallVector<Value*, 8> Elements(DestVecTy->getNumElements());
+ if (!CollectInsertionElements(IntInput, 0, Elements,
+ DestVecTy->getElementType()))
+ return 0;
+
+ // If we succeeded, we know that all of the element are specified by Elements
+ // or are zero if Elements has a null entry. Recast this as a set of
+ // insertions.
+ Value *Result = Constant::getNullValue(CI.getType());
+ for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
+ if (Elements[i] == 0) continue; // Unset element.
+
+ Result = IC.Builder->CreateInsertElement(Result, Elements[i],
+ IC.Builder->getInt32(i));
+ }
+
+ return Result;
+}
+
+
+/// OptimizeIntToFloatBitCast - See if we can optimize an integer->float/double
+/// bitcast. The various long double bitcasts can't get in here.
+static Instruction *OptimizeIntToFloatBitCast(BitCastInst &CI,InstCombiner &IC){
+ Value *Src = CI.getOperand(0);
+ const Type *DestTy = CI.getType();
+
+ // If this is a bitcast from int to float, check to see if the int is an
+ // extraction from a vector.
+ Value *VecInput = 0;
+ // bitcast(trunc(bitcast(somevector)))
+ if (match(Src, m_Trunc(m_BitCast(m_Value(VecInput)))) &&
+ isa<VectorType>(VecInput->getType())) {
+ const VectorType *VecTy = cast<VectorType>(VecInput->getType());
+ unsigned DestWidth = DestTy->getPrimitiveSizeInBits();
+
+ if (VecTy->getPrimitiveSizeInBits() % DestWidth == 0) {
+ // If the element type of the vector doesn't match the result type,
+ // bitcast it to be a vector type we can extract from.
+ if (VecTy->getElementType() != DestTy) {
+ VecTy = VectorType::get(DestTy,
+ VecTy->getPrimitiveSizeInBits() / DestWidth);
+ VecInput = IC.Builder->CreateBitCast(VecInput, VecTy);
+ }
+
+ return ExtractElementInst::Create(VecInput, IC.Builder->getInt32(0));
+ }
+ }
+
+ // bitcast(trunc(lshr(bitcast(somevector), cst))
+ ConstantInt *ShAmt = 0;
+ if (match(Src, m_Trunc(m_LShr(m_BitCast(m_Value(VecInput)),
+ m_ConstantInt(ShAmt)))) &&
+ isa<VectorType>(VecInput->getType())) {
+ const VectorType *VecTy = cast<VectorType>(VecInput->getType());
+ unsigned DestWidth = DestTy->getPrimitiveSizeInBits();
+ if (VecTy->getPrimitiveSizeInBits() % DestWidth == 0 &&
+ ShAmt->getZExtValue() % DestWidth == 0) {
+ // If the element type of the vector doesn't match the result type,
+ // bitcast it to be a vector type we can extract from.
+ if (VecTy->getElementType() != DestTy) {
+ VecTy = VectorType::get(DestTy,
+ VecTy->getPrimitiveSizeInBits() / DestWidth);
+ VecInput = IC.Builder->CreateBitCast(VecInput, VecTy);
+ }
+
+ unsigned Elt = ShAmt->getZExtValue() / DestWidth;
+ return ExtractElementInst::Create(VecInput, IC.Builder->getInt32(Elt));
+ }
+ }
+ return 0;
+}
Instruction *InstCombiner::visitBitCast(BitCastInst &CI) {
// If the operands are integer typed then apply the integer transforms,
((Instruction*)NULL));
}
}
+
+ // Try to optimize int -> float bitcasts.
+ if ((DestTy->isFloatTy() || DestTy->isDoubleTy()) && isa<IntegerType>(SrcTy))
+ if (Instruction *I = OptimizeIntToFloatBitCast(CI, *this))
+ return I;
if (const VectorType *DestVTy = dyn_cast<VectorType>(DestTy)) {
if (DestVTy->getNumElements() == 1 && !SrcTy->isVectorTy()) {
// 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),
+ if (isa<IntegerType>(SrcTy)) {
+ // 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<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;
+ return I;
+ }
+
+ // If the input is an 'or' instruction, we may be doing shifts and ors to
+ // assemble the elements of the vector manually. Try to rip the code out
+ // and replace it with insertelements.
+ if (Value *V = OptimizeIntegerToVectorInsertions(CI, *this))
+ return ReplaceInstUsesWith(CI, V);
}
}
projects / oota-llvm.git / blobdiff