// Otherwise, return null.
//
static inline Value *dyn_castFoldableMul(Value *V, ConstantInt *&CST) {
- if (!V->hasOneUse() || !V->getType()->isInteger())
+ if (!V->hasOneUse() || !V->getType()->isIntegerTy())
return 0;
Instruction *I = dyn_cast<Instruction>(V);
}
Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
- bool Changed = SimplifyCommutative(I);
+ bool Changed = SimplifyAssociativeOrCommutative(I);
Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
if (Value *V = SimplifyAddInst(LHS, RHS, I.hasNoSignedWrap(),
I.hasNoUnsignedWrap(), TD))
return ReplaceInstUsesWith(I, V);
-
- if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
- if (ConstantInt *CI = dyn_cast<ConstantInt>(RHSC)) {
- // X + (signbit) --> X ^ signbit
- const APInt& Val = CI->getValue();
- uint32_t BitWidth = Val.getBitWidth();
- if (Val == APInt::getSignBit(BitWidth))
- return BinaryOperator::CreateXor(LHS, RHS);
-
- // See if SimplifyDemandedBits can simplify this. This handles stuff like
- // (X & 254)+1 -> (X&254)|1
- if (SimplifyDemandedInstructionBits(I))
- return &I;
-
- // zext(bool) + C -> bool ? C + 1 : C
- if (ZExtInst *ZI = dyn_cast<ZExtInst>(LHS))
- if (ZI->getSrcTy() == Type::getInt1Ty(I.getContext()))
- return SelectInst::Create(ZI->getOperand(0), AddOne(CI), CI);
- }
+ // (A*B)+(A*C) -> A*(B+C) etc
+ if (Value *V = SimplifyUsingDistributiveLaws(I))
+ return ReplaceInstUsesWith(I, V);
- if (isa<PHINode>(LHS))
- if (Instruction *NV = FoldOpIntoPhi(I))
- return NV;
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) {
+ // X + (signbit) --> X ^ signbit
+ const APInt &Val = CI->getValue();
+ if (Val.isSignBit())
+ return BinaryOperator::CreateXor(LHS, RHS);
+
+ // See if SimplifyDemandedBits can simplify this. This handles stuff like
+ // (X & 254)+1 -> (X&254)|1
+ if (SimplifyDemandedInstructionBits(I))
+ return &I;
+
+ // zext(bool) + C -> bool ? C + 1 : C
+ if (ZExtInst *ZI = dyn_cast<ZExtInst>(LHS))
+ if (ZI->getSrcTy()->isIntegerTy(1))
+ return SelectInst::Create(ZI->getOperand(0), AddOne(CI), CI);
- ConstantInt *XorRHS = 0;
- Value *XorLHS = 0;
- if (isa<ConstantInt>(RHSC) &&
- match(LHS, m_Xor(m_Value(XorLHS), m_ConstantInt(XorRHS)))) {
+ Value *XorLHS = 0; ConstantInt *XorRHS = 0;
+ if (match(LHS, m_Xor(m_Value(XorLHS), m_ConstantInt(XorRHS)))) {
uint32_t TySizeBits = I.getType()->getScalarSizeInBits();
- const APInt& RHSVal = cast<ConstantInt>(RHSC)->getValue();
+ const APInt &RHSVal = CI->getValue();
+ unsigned ExtendAmt = 0;
+ // If we have ADD(XOR(AND(X, 0xFF), 0x80), 0xF..F80), it's a sext.
+ // If we have ADD(XOR(AND(X, 0xFF), 0xF..F80), 0x80), it's a sext.
+ if (XorRHS->getValue() == -RHSVal) {
+ if (RHSVal.isPowerOf2())
+ ExtendAmt = TySizeBits - RHSVal.logBase2() - 1;
+ else if (XorRHS->getValue().isPowerOf2())
+ ExtendAmt = TySizeBits - XorRHS->getValue().logBase2() - 1;
+ }
- uint32_t Size = TySizeBits / 2;
- APInt C0080Val(APInt(TySizeBits, 1ULL).shl(Size - 1));
- APInt CFF80Val(-C0080Val);
- do {
- if (TySizeBits > Size) {
- // If we have ADD(XOR(AND(X, 0xFF), 0x80), 0xF..F80), it's a sext.
- // If we have ADD(XOR(AND(X, 0xFF), 0xF..F80), 0x80), it's a sext.
- if ((RHSVal == CFF80Val && XorRHS->getValue() == C0080Val) ||
- (RHSVal == C0080Val && XorRHS->getValue() == CFF80Val)) {
- // This is a sign extend if the top bits are known zero.
- if (!MaskedValueIsZero(XorLHS,
- APInt::getHighBitsSet(TySizeBits, TySizeBits - Size)))
- Size = 0; // Not a sign ext, but can't be any others either.
- break;
- }
- }
- Size >>= 1;
- C0080Val = APIntOps::lshr(C0080Val, Size);
- CFF80Val = APIntOps::ashr(CFF80Val, Size);
- } while (Size >= 1);
+ if (ExtendAmt) {
+ APInt Mask = APInt::getHighBitsSet(TySizeBits, ExtendAmt);
+ if (!MaskedValueIsZero(XorLHS, Mask))
+ ExtendAmt = 0;
+ }
- // FIXME: This shouldn't be necessary. When the backends can handle types
- // with funny bit widths then this switch statement should be removed. It
- // is just here to get the size of the "middle" type back up to something
- // that the back ends can handle.
- const Type *MiddleType = 0;
- switch (Size) {
- default: break;
- case 32:
- case 16:
- case 8: MiddleType = IntegerType::get(I.getContext(), Size); break;
+ if (ExtendAmt) {
+ Constant *ShAmt = ConstantInt::get(I.getType(), ExtendAmt);
+ Value *NewShl = Builder->CreateShl(XorLHS, ShAmt, "sext");
+ return BinaryOperator::CreateAShr(NewShl, ShAmt);
}
- if (MiddleType) {
- Value *NewTrunc = Builder->CreateTrunc(XorLHS, MiddleType, "sext");
- return new SExtInst(NewTrunc, I.getType(), I.getName());
+
+ // If this is a xor that was canonicalized from a sub, turn it back into
+ // a sub and fuse this add with it.
+ if (LHS->hasOneUse() && (XorRHS->getValue()+1).isPowerOf2()) {
+ IntegerType *IT = cast<IntegerType>(I.getType());
+ APInt LHSKnownOne(IT->getBitWidth(), 0);
+ APInt LHSKnownZero(IT->getBitWidth(), 0);
+ ComputeMaskedBits(XorLHS, LHSKnownZero, LHSKnownOne);
+ if ((XorRHS->getValue() | LHSKnownZero).isAllOnesValue())
+ return BinaryOperator::CreateSub(ConstantExpr::getAdd(XorRHS, CI),
+ XorLHS);
}
}
}
- if (I.getType()->isInteger(1))
- return BinaryOperator::CreateXor(LHS, RHS);
+ if (isa<Constant>(RHS) && isa<PHINode>(LHS))
+ if (Instruction *NV = FoldOpIntoPhi(I))
+ return NV;
- if (I.getType()->isInteger()) {
- // X + X --> X << 1
- if (LHS == RHS)
- return BinaryOperator::CreateShl(LHS, ConstantInt::get(I.getType(), 1));
+ if (I.getType()->isIntegerTy(1))
+ return BinaryOperator::CreateXor(LHS, RHS);
- if (Instruction *RHSI = dyn_cast<Instruction>(RHS)) {
- if (RHSI->getOpcode() == Instruction::Sub)
- if (LHS == RHSI->getOperand(1)) // A + (B - A) --> B
- return ReplaceInstUsesWith(I, RHSI->getOperand(0));
- }
- if (Instruction *LHSI = dyn_cast<Instruction>(LHS)) {
- if (LHSI->getOpcode() == Instruction::Sub)
- if (RHS == LHSI->getOperand(1)) // (B - A) + A --> B
- return ReplaceInstUsesWith(I, LHSI->getOperand(0));
- }
+ // X + X --> X << 1
+ if (LHS == RHS) {
+ BinaryOperator *New =
+ BinaryOperator::CreateShl(LHS, ConstantInt::get(I.getType(), 1));
+ New->setHasNoSignedWrap(I.hasNoSignedWrap());
+ New->setHasNoUnsignedWrap(I.hasNoUnsignedWrap());
+ return New;
}
// -A + B --> B - A
// -A + -B --> -(A + B)
if (Value *LHSV = dyn_castNegVal(LHS)) {
- if (LHS->getType()->isIntOrIntVector()) {
+ if (!isa<Constant>(RHS))
if (Value *RHSV = dyn_castNegVal(RHS)) {
Value *NewAdd = Builder->CreateAdd(LHSV, RHSV, "sum");
return BinaryOperator::CreateNeg(NewAdd);
}
- }
return BinaryOperator::CreateSub(RHS, LHSV);
}
if (dyn_castFoldableMul(RHS, C2) == LHS)
return BinaryOperator::CreateMul(LHS, AddOne(C2));
- // X + ~X --> -1 since ~X = -X-1
- if (match(LHS, m_Not(m_Specific(RHS))) ||
- match(RHS, m_Not(m_Specific(LHS))))
- return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
-
// A+B --> A|B iff A and B have no bits set in common.
- if (const IntegerType *IT = dyn_cast<IntegerType>(I.getType())) {
- APInt Mask = APInt::getAllOnesValue(IT->getBitWidth());
+ if (IntegerType *IT = dyn_cast<IntegerType>(I.getType())) {
APInt LHSKnownOne(IT->getBitWidth(), 0);
APInt LHSKnownZero(IT->getBitWidth(), 0);
- ComputeMaskedBits(LHS, Mask, LHSKnownZero, LHSKnownOne);
+ ComputeMaskedBits(LHS, LHSKnownZero, LHSKnownOne);
if (LHSKnownZero != 0) {
APInt RHSKnownOne(IT->getBitWidth(), 0);
APInt RHSKnownZero(IT->getBitWidth(), 0);
- ComputeMaskedBits(RHS, Mask, RHSKnownZero, RHSKnownOne);
+ ComputeMaskedBits(RHS, RHSKnownZero, RHSKnownOne);
// No bits in common -> bitwise or.
if ((LHSKnownZero|RHSKnownZero).isAllOnesValue())
}
// W*X + Y*Z --> W * (X+Z) iff W == Y
- if (I.getType()->isIntOrIntVector()) {
+ {
Value *W, *X, *Y, *Z;
if (match(LHS, m_Mul(m_Value(W), m_Value(X))) &&
match(RHS, m_Mul(m_Value(Y), m_Value(Z)))) {
// (X & FF00) + xx00 -> (X+xx00) & FF00
if (LHS->hasOneUse() &&
- match(LHS, m_And(m_Value(X), m_ConstantInt(C2)))) {
- Constant *Anded = ConstantExpr::getAnd(CRHS, C2);
- if (Anded == CRHS) {
- // See if all bits from the first bit set in the Add RHS up are included
- // in the mask. First, get the rightmost bit.
- const APInt &AddRHSV = CRHS->getValue();
-
- // Form a mask of all bits from the lowest bit added through the top.
- APInt AddRHSHighBits(~((AddRHSV & -AddRHSV)-1));
-
- // See if the and mask includes all of these bits.
- APInt AddRHSHighBitsAnd(AddRHSHighBits & C2->getValue());
-
- if (AddRHSHighBits == AddRHSHighBitsAnd) {
- // Okay, the xform is safe. Insert the new add pronto.
- Value *NewAdd = Builder->CreateAdd(X, CRHS, LHS->getName());
- return BinaryOperator::CreateAnd(NewAdd, C2);
- }
+ match(LHS, m_And(m_Value(X), m_ConstantInt(C2))) &&
+ CRHS->getValue() == (CRHS->getValue() & C2->getValue())) {
+ // See if all bits from the first bit set in the Add RHS up are included
+ // in the mask. First, get the rightmost bit.
+ const APInt &AddRHSV = CRHS->getValue();
+
+ // Form a mask of all bits from the lowest bit added through the top.
+ APInt AddRHSHighBits(~((AddRHSV & -AddRHSV)-1));
+
+ // See if the and mask includes all of these bits.
+ APInt AddRHSHighBitsAnd(AddRHSHighBits & C2->getValue());
+
+ if (AddRHSHighBits == AddRHSHighBitsAnd) {
+ // Okay, the xform is safe. Insert the new add pronto.
+ Value *NewAdd = Builder->CreateAdd(X, CRHS, LHS->getName());
+ return BinaryOperator::CreateAnd(NewAdd, C2);
}
}
// Can we fold the add into the argument of the select?
// We check both true and false select arguments for a matching subtract.
- if (match(FV, m_Zero()) &&
- match(TV, m_Sub(m_Value(N), m_Specific(A))))
+ if (match(FV, m_Zero()) && match(TV, m_Sub(m_Value(N), m_Specific(A))))
// Fold the add into the true select value.
return SelectInst::Create(SI->getCondition(), N, A);
- if (match(TV, m_Zero()) &&
- match(FV, m_Sub(m_Value(N), m_Specific(A))))
+
+ if (match(TV, m_Zero()) && match(FV, m_Sub(m_Value(N), m_Specific(A))))
// Fold the add into the false select value.
return SelectInst::Create(SI->getCondition(), A, N);
}
}
}
+ // Check for (x & y) + (x ^ y)
+ {
+ Value *A = 0, *B = 0;
+ if (match(RHS, m_Xor(m_Value(A), m_Value(B))) &&
+ (match(LHS, m_And(m_Specific(A), m_Specific(B))) ||
+ match(LHS, m_And(m_Specific(B), m_Specific(A)))))
+ return BinaryOperator::CreateOr(A, B);
+
+ if (match(LHS, m_Xor(m_Value(A), m_Value(B))) &&
+ (match(RHS, m_And(m_Specific(A), m_Specific(B))) ||
+ match(RHS, m_And(m_Specific(B), m_Specific(A)))))
+ return BinaryOperator::CreateOr(A, B);
+ }
+
return Changed ? &I : 0;
}
Instruction *InstCombiner::visitFAdd(BinaryOperator &I) {
- bool Changed = SimplifyCommutative(I);
+ bool Changed = SimplifyAssociativeOrCommutative(I);
Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
if (CFP->getValueAPF().isPosZero() && CannotBeNegativeZero(LHS))
return ReplaceInstUsesWith(I, LHS);
- // Check for (add double (sitofp x), y), see if we can merge this into an
+ // Check for (fadd double (sitofp x), y), see if we can merge this into an
// integer add followed by a promotion.
if (SIToFPInst *LHSConv = dyn_cast<SIToFPInst>(LHS)) {
- // (add double (sitofp x), fpcst) --> (sitofp (add int x, intcst))
+ // (fadd double (sitofp x), fpcst) --> (sitofp (add int x, intcst))
// ... if the constant fits in the integer value. This is useful for things
// like (double)(x & 1234) + 4.0 -> (double)((X & 1234)+4) which no longer
// requires a constant pool load, and generally allows the add to be better
}
}
- // (add double (sitofp x), (sitofp y)) --> (sitofp (add int x, y))
+ // (fadd double (sitofp x), (sitofp y)) --> (sitofp (add int x, y))
if (SIToFPInst *RHSConv = dyn_cast<SIToFPInst>(RHS)) {
// Only do this if x/y have the same type, if at last one of them has a
// single use (so we don't increase the number of int->fp conversions),
}
-/// EmitGEPOffset - Given a getelementptr instruction/constantexpr, emit the
-/// code necessary to compute the offset from the base pointer (without adding
-/// in the base pointer). Return the result as a signed integer of intptr size.
-Value *InstCombiner::EmitGEPOffset(User *GEP) {
- TargetData &TD = *getTargetData();
- gep_type_iterator GTI = gep_type_begin(GEP);
- const Type *IntPtrTy = TD.getIntPtrType(GEP->getContext());
- Value *Result = Constant::getNullValue(IntPtrTy);
-
- // Build a mask for high order bits.
- unsigned IntPtrWidth = TD.getPointerSizeInBits();
- uint64_t PtrSizeMask = ~0ULL >> (64-IntPtrWidth);
-
- for (User::op_iterator i = GEP->op_begin() + 1, e = GEP->op_end(); i != e;
- ++i, ++GTI) {
- Value *Op = *i;
- uint64_t Size = TD.getTypeAllocSize(GTI.getIndexedType()) & PtrSizeMask;
- if (ConstantInt *OpC = dyn_cast<ConstantInt>(Op)) {
- if (OpC->isZero()) continue;
-
- // Handle a struct index, which adds its field offset to the pointer.
- if (const StructType *STy = dyn_cast<StructType>(*GTI)) {
- Size = TD.getStructLayout(STy)->getElementOffset(OpC->getZExtValue());
-
- Result = Builder->CreateAdd(Result,
- ConstantInt::get(IntPtrTy, Size),
- GEP->getName()+".offs");
- continue;
- }
-
- Constant *Scale = ConstantInt::get(IntPtrTy, Size);
- Constant *OC =
- ConstantExpr::getIntegerCast(OpC, IntPtrTy, true /*SExt*/);
- Scale = ConstantExpr::getMul(OC, Scale);
- // Emit an add instruction.
- Result = Builder->CreateAdd(Result, Scale, GEP->getName()+".offs");
- continue;
- }
- // Convert to correct type.
- if (Op->getType() != IntPtrTy)
- Op = Builder->CreateIntCast(Op, IntPtrTy, true, Op->getName()+".c");
- if (Size != 1) {
- Constant *Scale = ConstantInt::get(IntPtrTy, Size);
- // We'll let instcombine(mul) convert this to a shl if possible.
- Op = Builder->CreateMul(Op, Scale, GEP->getName()+".idx");
- }
-
- // Emit an add instruction.
- Result = Builder->CreateAdd(Op, Result, GEP->getName()+".offs");
- }
- return Result;
-}
-
-
-
-
/// Optimize pointer differences into the same array into a size. Consider:
/// &A[10] - &A[0]: we should compile this to "10". LHS/RHS are the pointer
/// operands to the ptrtoint instructions for the LHS/RHS of the subtract.
///
Value *InstCombiner::OptimizePointerDifference(Value *LHS, Value *RHS,
- const Type *Ty) {
+ Type *Ty) {
assert(TD && "Must have target data info for this");
// If LHS is a gep based on RHS or RHS is a gep based on LHS, we can optimize
// this.
bool Swapped = false;
- GetElementPtrInst *GEP = 0;
- ConstantExpr *CstGEP = 0;
-
- // TODO: Could also optimize &A[i] - &A[j] -> "i-j", and "&A.foo[i] - &A.foo".
+ GEPOperator *GEP1 = 0, *GEP2 = 0;
+
// For now we require one side to be the base pointer "A" or a constant
- // expression derived from it.
- if (GetElementPtrInst *LHSGEP = dyn_cast<GetElementPtrInst>(LHS)) {
+ // GEP derived from it.
+ if (GEPOperator *LHSGEP = dyn_cast<GEPOperator>(LHS)) {
// (gep X, ...) - X
if (LHSGEP->getOperand(0) == RHS) {
- GEP = LHSGEP;
+ GEP1 = LHSGEP;
Swapped = false;
- } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(RHS)) {
- // (gep X, ...) - (ce_gep X, ...)
- if (CE->getOpcode() == Instruction::GetElementPtr &&
- LHSGEP->getOperand(0) == CE->getOperand(0)) {
- CstGEP = CE;
- GEP = LHSGEP;
+ } else if (GEPOperator *RHSGEP = dyn_cast<GEPOperator>(RHS)) {
+ // (gep X, ...) - (gep X, ...)
+ if (LHSGEP->getOperand(0)->stripPointerCasts() ==
+ RHSGEP->getOperand(0)->stripPointerCasts()) {
+ GEP2 = RHSGEP;
+ GEP1 = LHSGEP;
Swapped = false;
}
}
}
- if (GetElementPtrInst *RHSGEP = dyn_cast<GetElementPtrInst>(RHS)) {
+ if (GEPOperator *RHSGEP = dyn_cast<GEPOperator>(RHS)) {
// X - (gep X, ...)
if (RHSGEP->getOperand(0) == LHS) {
- GEP = RHSGEP;
+ GEP1 = RHSGEP;
Swapped = true;
- } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(LHS)) {
- // (ce_gep X, ...) - (gep X, ...)
- if (CE->getOpcode() == Instruction::GetElementPtr &&
- RHSGEP->getOperand(0) == CE->getOperand(0)) {
- CstGEP = CE;
- GEP = RHSGEP;
+ } else if (GEPOperator *LHSGEP = dyn_cast<GEPOperator>(LHS)) {
+ // (gep X, ...) - (gep X, ...)
+ if (RHSGEP->getOperand(0)->stripPointerCasts() ==
+ LHSGEP->getOperand(0)->stripPointerCasts()) {
+ GEP2 = LHSGEP;
+ GEP1 = RHSGEP;
Swapped = true;
}
}
}
- if (GEP == 0)
+ // Avoid duplicating the arithmetic if GEP2 has non-constant indices and
+ // multiple users.
+ if (GEP1 == 0 ||
+ (GEP2 != 0 && !GEP2->hasAllConstantIndices() && !GEP2->hasOneUse()))
return 0;
// Emit the offset of the GEP and an intptr_t.
- Value *Result = EmitGEPOffset(GEP);
+ Value *Result = EmitGEPOffset(GEP1);
// If we had a constant expression GEP on the other side offsetting the
// pointer, subtract it from the offset we have.
- if (CstGEP) {
- Value *CstOffset = EmitGEPOffset(CstGEP);
- Result = Builder->CreateSub(Result, CstOffset);
+ if (GEP2) {
+ Value *Offset = EmitGEPOffset(GEP2);
+ Result = Builder->CreateSub(Result, Offset);
}
-
// If we have p - gep(p, ...) then we have to negate the result.
if (Swapped)
Instruction *InstCombiner::visitSub(BinaryOperator &I) {
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
- if (Op0 == Op1) // sub X, X -> 0
- return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
+ if (Value *V = SimplifySubInst(Op0, Op1, I.hasNoSignedWrap(),
+ I.hasNoUnsignedWrap(), TD))
+ return ReplaceInstUsesWith(I, V);
+
+ // (A*B)-(A*C) -> A*(B-C) etc
+ if (Value *V = SimplifyUsingDistributiveLaws(I))
+ return ReplaceInstUsesWith(I, V);
// If this is a 'B = x-(-A)', change to B = x+A. This preserves NSW/NUW.
if (Value *V = dyn_castNegVal(Op1)) {
return Res;
}
- if (isa<UndefValue>(Op0))
- return ReplaceInstUsesWith(I, Op0); // undef - X -> undef
- if (isa<UndefValue>(Op1))
- return ReplaceInstUsesWith(I, Op1); // X - undef -> undef
- if (I.getType()->isInteger(1))
+ if (I.getType()->isIntegerTy(1))
return BinaryOperator::CreateXor(Op0, Op1);
+
+ // Replace (-1 - A) with (~A).
+ if (match(Op0, m_AllOnes()))
+ return BinaryOperator::CreateNot(Op1);
if (ConstantInt *C = dyn_cast<ConstantInt>(Op0)) {
- // Replace (-1 - A) with (~A).
- if (C->isAllOnesValue())
- return BinaryOperator::CreateNot(Op1);
-
// C - ~X == X + (1+C)
Value *X = 0;
if (match(Op1, m_Not(m_Value(X))))
// -(X >>u 31) -> (X >>s 31)
// -(X >>s 31) -> (X >>u 31)
if (C->isZero()) {
- if (BinaryOperator *SI = dyn_cast<BinaryOperator>(Op1)) {
- if (SI->getOpcode() == Instruction::LShr) {
- if (ConstantInt *CU = dyn_cast<ConstantInt>(SI->getOperand(1))) {
- // Check to see if we are shifting out everything but the sign bit.
- if (CU->getLimitedValue(SI->getType()->getPrimitiveSizeInBits()) ==
- SI->getType()->getPrimitiveSizeInBits()-1) {
- // Ok, the transformation is safe. Insert AShr.
- return BinaryOperator::Create(Instruction::AShr,
- SI->getOperand(0), CU, SI->getName());
- }
- }
- } else if (SI->getOpcode() == Instruction::AShr) {
- if (ConstantInt *CU = dyn_cast<ConstantInt>(SI->getOperand(1))) {
- // Check to see if we are shifting out everything but the sign bit.
- if (CU->getLimitedValue(SI->getType()->getPrimitiveSizeInBits()) ==
- SI->getType()->getPrimitiveSizeInBits()-1) {
- // Ok, the transformation is safe. Insert LShr.
- return BinaryOperator::CreateLShr(
- SI->getOperand(0), CU, SI->getName());
- }
- }
- }
- }
+ Value *X; ConstantInt *CI;
+ if (match(Op1, m_LShr(m_Value(X), m_ConstantInt(CI))) &&
+ // Verify we are shifting out everything but the sign bit.
+ CI->getValue() == I.getType()->getPrimitiveSizeInBits()-1)
+ return BinaryOperator::CreateAShr(X, CI);
+
+ if (match(Op1, m_AShr(m_Value(X), m_ConstantInt(CI))) &&
+ // Verify we are shifting out everything but the sign bit.
+ CI->getValue() == I.getType()->getPrimitiveSizeInBits()-1)
+ return BinaryOperator::CreateLShr(X, CI);
}
// Try to fold constant sub into select arguments.
if (Instruction *R = FoldOpIntoSelect(I, SI))
return R;
- // C - zext(bool) -> bool ? C - 1 : C
- if (ZExtInst *ZI = dyn_cast<ZExtInst>(Op1))
- if (ZI->getSrcTy() == Type::getInt1Ty(I.getContext()))
- return SelectInst::Create(ZI->getOperand(0), SubOne(C), C);
+ // C-(X+C2) --> (C-C2)-X
+ ConstantInt *C2;
+ if (match(Op1, m_Add(m_Value(X), m_ConstantInt(C2))))
+ return BinaryOperator::CreateSub(ConstantExpr::getSub(C, C2), X);
+
+ if (SimplifyDemandedInstructionBits(I))
+ return &I;
}
- if (BinaryOperator *Op1I = dyn_cast<BinaryOperator>(Op1)) {
- if (Op1I->getOpcode() == Instruction::Add) {
- if (Op1I->getOperand(0) == Op0) // X-(X+Y) == -Y
- return BinaryOperator::CreateNeg(Op1I->getOperand(1),
- I.getName());
- else if (Op1I->getOperand(1) == Op0) // X-(Y+X) == -Y
- return BinaryOperator::CreateNeg(Op1I->getOperand(0),
- I.getName());
- else if (ConstantInt *CI1 = dyn_cast<ConstantInt>(I.getOperand(0))) {
- if (ConstantInt *CI2 = dyn_cast<ConstantInt>(Op1I->getOperand(1)))
- // C1-(X+C2) --> (C1-C2)-X
- return BinaryOperator::CreateSub(
- ConstantExpr::getSub(CI1, CI2), Op1I->getOperand(0));
- }
+
+ { Value *Y;
+ // X-(X+Y) == -Y X-(Y+X) == -Y
+ if (match(Op1, m_Add(m_Specific(Op0), m_Value(Y))) ||
+ match(Op1, m_Add(m_Value(Y), m_Specific(Op0))))
+ return BinaryOperator::CreateNeg(Y);
+
+ // (X-Y)-X == -Y
+ if (match(Op0, m_Sub(m_Specific(Op1), m_Value(Y))))
+ return BinaryOperator::CreateNeg(Y);
+ }
+
+ if (Op1->hasOneUse()) {
+ Value *X = 0, *Y = 0, *Z = 0;
+ Constant *C = 0;
+ ConstantInt *CI = 0;
+
+ // (X - (Y - Z)) --> (X + (Z - Y)).
+ if (match(Op1, m_Sub(m_Value(Y), m_Value(Z))))
+ return BinaryOperator::CreateAdd(Op0,
+ Builder->CreateSub(Z, Y, Op1->getName()));
+
+ // (X - (X & Y)) --> (X & ~Y)
+ //
+ if (match(Op1, m_And(m_Value(Y), m_Specific(Op0))) ||
+ match(Op1, m_And(m_Specific(Op0), m_Value(Y))))
+ return BinaryOperator::CreateAnd(Op0,
+ Builder->CreateNot(Y, Y->getName() + ".not"));
+
+ // 0 - (X sdiv C) -> (X sdiv -C)
+ if (match(Op1, m_SDiv(m_Value(X), m_Constant(C))) &&
+ match(Op0, m_Zero()))
+ return BinaryOperator::CreateSDiv(X, ConstantExpr::getNeg(C));
+
+ // 0 - (X << Y) -> (-X << Y) when X is freely negatable.
+ if (match(Op1, m_Shl(m_Value(X), m_Value(Y))) && match(Op0, m_Zero()))
+ if (Value *XNeg = dyn_castNegVal(X))
+ return BinaryOperator::CreateShl(XNeg, Y);
+
+ // X - X*C --> X * (1-C)
+ if (match(Op1, m_Mul(m_Specific(Op0), m_ConstantInt(CI)))) {
+ Constant *CP1 = ConstantExpr::getSub(ConstantInt::get(I.getType(),1), CI);
+ return BinaryOperator::CreateMul(Op0, CP1);
}
- if (Op1I->hasOneUse()) {
- // Replace (x - (y - z)) with (x + (z - y)) if the (y - z) subexpression
- // is not used by anyone else...
- //
- if (Op1I->getOpcode() == Instruction::Sub) {
- // Swap the two operands of the subexpr...
- Value *IIOp0 = Op1I->getOperand(0), *IIOp1 = Op1I->getOperand(1);
- Op1I->setOperand(0, IIOp1);
- Op1I->setOperand(1, IIOp0);
-
- // Create the new top level add instruction...
- return BinaryOperator::CreateAdd(Op0, Op1);
- }
-
- // Replace (A - (A & B)) with (A & ~B) if this is the only use of (A&B)...
- //
- if (Op1I->getOpcode() == Instruction::And &&
- (Op1I->getOperand(0) == Op0 || Op1I->getOperand(1) == Op0)) {
- Value *OtherOp = Op1I->getOperand(Op1I->getOperand(0) == Op0);
-
- Value *NewNot = Builder->CreateNot(OtherOp, "B.not");
- return BinaryOperator::CreateAnd(Op0, NewNot);
- }
-
- // 0 - (X sdiv C) -> (X sdiv -C)
- if (Op1I->getOpcode() == Instruction::SDiv)
- if (ConstantInt *CSI = dyn_cast<ConstantInt>(Op0))
- if (CSI->isZero())
- if (Constant *DivRHS = dyn_cast<Constant>(Op1I->getOperand(1)))
- return BinaryOperator::CreateSDiv(Op1I->getOperand(0),
- ConstantExpr::getNeg(DivRHS));
-
- // X - X*C --> X * (1-C)
- ConstantInt *C2 = 0;
- if (dyn_castFoldableMul(Op1I, C2) == Op0) {
- Constant *CP1 =
- ConstantExpr::getSub(ConstantInt::get(I.getType(), 1),
- C2);
- return BinaryOperator::CreateMul(Op0, CP1);
- }
+ // X - X<<C --> X * (1-(1<<C))
+ if (match(Op1, m_Shl(m_Specific(Op0), m_ConstantInt(CI)))) {
+ Constant *One = ConstantInt::get(I.getType(), 1);
+ C = ConstantExpr::getSub(One, ConstantExpr::getShl(One, CI));
+ return BinaryOperator::CreateMul(Op0, C);
}
- }
-
- if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
- if (Op0I->getOpcode() == Instruction::Add) {
- if (Op0I->getOperand(0) == Op1) // (Y+X)-Y == X
- return ReplaceInstUsesWith(I, Op0I->getOperand(1));
- else if (Op0I->getOperand(1) == Op1) // (X+Y)-Y == X
- return ReplaceInstUsesWith(I, Op0I->getOperand(0));
- } else if (Op0I->getOpcode() == Instruction::Sub) {
- if (Op0I->getOperand(0) == Op1) // (X-Y)-X == -Y
- return BinaryOperator::CreateNeg(Op0I->getOperand(1),
- I.getName());
+
+ // X - A*-B -> X + A*B
+ // X - -A*B -> X + A*B
+ Value *A, *B;
+ if (match(Op1, m_Mul(m_Value(A), m_Neg(m_Value(B)))) ||
+ match(Op1, m_Mul(m_Neg(m_Value(A)), m_Value(B))))
+ return BinaryOperator::CreateAdd(Op0, Builder->CreateMul(A, B));
+
+ // X - A*CI -> X + A*-CI
+ // X - CI*A -> X + A*-CI
+ if (match(Op1, m_Mul(m_Value(A), m_ConstantInt(CI))) ||
+ match(Op1, m_Mul(m_ConstantInt(CI), m_Value(A)))) {
+ Value *NewMul = Builder->CreateMul(A, ConstantExpr::getNeg(CI));
+ return BinaryOperator::CreateAdd(Op0, NewMul);
}
}
projects / oota-llvm.git / blobdiff