Instruction *FoldAndOfICmps(Instruction &I, ICmpInst *LHS, ICmpInst *RHS);
Instruction *visitAnd(BinaryOperator &I);
Instruction *FoldOrOfICmps(Instruction &I, ICmpInst *LHS, ICmpInst *RHS);
- Instruction *FoldOrWithConstants(BinaryOperator &I,
+ Instruction *FoldOrWithConstants(BinaryOperator &I, Value *Op,
Value *A, Value *B, Value *C);
Instruction *visitOr (BinaryOperator &I);
Instruction *visitXor(BinaryOperator &I);
}
}
- // UpdateValueUsesWith - This method is to be used when an value is
- // found to be replacable with another preexisting expression or was
- // updated. Here we add all uses of I to the worklist, replace all uses of
- // I with the new value (unless the instruction was just updated), then
- // return true, so that the inst combiner will know that I was modified.
- //
- bool UpdateValueUsesWith(Value *Old, Value *New) {
- AddUsersToWorkList(*Old); // Add all modified instrs to worklist
- if (Old != New)
- Old->replaceAllUsesWith(New);
- if (Instruction *I = dyn_cast<Instruction>(Old))
- AddToWorkList(I);
- if (Instruction *I = dyn_cast<Instruction>(New))
- AddToWorkList(I);
- return true;
- }
-
// EraseInstFromFunction - When dealing with an instruction that has side
// effects or produces a void value, we can't rely on DCE to delete the
// instruction. Instead, visit methods should return the value returned by
/// most-complex to least-complex order.
bool SimplifyCompare(CmpInst &I);
- /// SimplifyDemandedBits - Attempts to replace V with a simpler value based
- /// on the demanded bits.
- bool SimplifyDemandedBits(Value *V, APInt DemandedMask,
+ /// SimplifyDemandedUseBits - Attempts to replace V with a simpler value
+ /// based on the demanded bits.
+ Value *SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
+ APInt& KnownZero, APInt& KnownOne,
+ unsigned Depth);
+ bool SimplifyDemandedBits(Use &U, APInt DemandedMask,
APInt& KnownZero, APInt& KnownOne,
- unsigned Depth = 0);
-
- Value *SimplifyDemandedVectorElts(Value *V, uint64_t DemandedElts,
- uint64_t &UndefElts, unsigned Depth = 0);
+ unsigned Depth=0);
+
+ /// SimplifyDemandedInstructionBits - Inst is an integer instruction that
+ /// SimplifyDemandedBits knows about. See if the instruction has any
+ /// properties that allow us to simplify its operands.
+ bool SimplifyDemandedInstructionBits(Instruction &Inst);
+
+ Value *SimplifyDemandedVectorElts(Value *V, APInt DemandedElts,
+ APInt& UndefElts, unsigned Depth = 0);
// FoldOpIntoPhi - Given a binary operator or cast instruction which has a
// PHI node as operand #0, see if we can fold the instruction into the PHI
Value *EvaluateInDifferentType(Value *V, const Type *Ty, bool isSigned);
bool CanEvaluateInDifferentType(Value *V, const IntegerType *Ty,
- unsigned CastOpc,
- int &NumCastsRemoved);
+ unsigned CastOpc, int &NumCastsRemoved);
unsigned GetOrEnforceKnownAlignment(Value *V,
unsigned PrefAlign = 0);
Max = KnownOne|UnknownBits;
}
-/// SimplifyDemandedBits - This function attempts to replace V with a simpler
-/// value based on the demanded bits. When this function is called, it is known
+/// SimplifyDemandedInstructionBits - Inst is an integer instruction that
+/// SimplifyDemandedBits knows about. See if the instruction has any
+/// properties that allow us to simplify its operands.
+bool InstCombiner::SimplifyDemandedInstructionBits(Instruction &Inst) {
+ unsigned BitWidth = cast<IntegerType>(Inst.getType())->getBitWidth();
+ APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
+ APInt DemandedMask(APInt::getAllOnesValue(BitWidth));
+
+ Value *V = SimplifyDemandedUseBits(&Inst, DemandedMask,
+ KnownZero, KnownOne, 0);
+ if (V == 0) return false;
+ if (V == &Inst) return true;
+ ReplaceInstUsesWith(Inst, V);
+ return true;
+}
+
+/// SimplifyDemandedBits - This form of SimplifyDemandedBits simplifies the
+/// specified instruction operand if possible, updating it in place. It returns
+/// true if it made any change and false otherwise.
+bool InstCombiner::SimplifyDemandedBits(Use &U, APInt DemandedMask,
+ APInt &KnownZero, APInt &KnownOne,
+ unsigned Depth) {
+ Value *NewVal = SimplifyDemandedUseBits(U.get(), DemandedMask,
+ KnownZero, KnownOne, Depth);
+ if (NewVal == 0) return false;
+ U.set(NewVal);
+ return true;
+}
+
+
+/// SimplifyDemandedUseBits - This function attempts to replace V with a simpler
+/// value based on the demanded bits. When this function is called, it is known
/// that only the bits set in DemandedMask of the result of V are ever used
/// downstream. Consequently, depending on the mask and V, it may be possible
/// to replace V with a constant or one of its operands. In such cases, this
/// function does the replacement and returns true. In all other cases, it
/// returns false after analyzing the expression and setting KnownOne and known
-/// to be one in the expression. KnownZero contains all the bits that are known
+/// to be one in the expression. KnownZero contains all the bits that are known
/// to be zero in the expression. These are provided to potentially allow the
/// caller (which might recursively be SimplifyDemandedBits itself) to simplify
/// the expression. KnownOne and KnownZero always follow the invariant that
/// the bits in KnownOne and KnownZero may only be accurate for those bits set
/// in DemandedMask. Note also that the bitwidth of V, DemandedMask, KnownZero
/// and KnownOne must all be the same.
-bool InstCombiner::SimplifyDemandedBits(Value *V, APInt DemandedMask,
- APInt& KnownZero, APInt& KnownOne,
- unsigned Depth) {
+///
+/// This returns null if it did not change anything and it permits no
+/// simplification. This returns V itself if it did some simplification of V's
+/// operands based on the information about what bits are demanded. This returns
+/// some other non-null value if it found out that V is equal to another value
+/// in the context where the specified bits are demanded, but not for all users.
+Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
+ APInt &KnownZero, APInt &KnownOne,
+ unsigned Depth) {
assert(V != 0 && "Null pointer of Value???");
assert(Depth <= 6 && "Limit Search Depth");
uint32_t BitWidth = DemandedMask.getBitWidth();
// We know all of the bits for a constant!
KnownOne = CI->getValue() & DemandedMask;
KnownZero = ~KnownOne & DemandedMask;
- return false;
+ return 0;
}
- KnownZero.clear();
+ KnownZero.clear();
KnownOne.clear();
- if (!V->hasOneUse()) { // Other users may use these bits.
- if (Depth != 0) { // Not at the root.
- // Just compute the KnownZero/KnownOne bits to simplify things downstream.
- ComputeMaskedBits(V, DemandedMask, KnownZero, KnownOne, Depth);
- return false;
- }
- // If this is the root being simplified, allow it to have multiple uses,
- // just set the DemandedMask to all bits.
- DemandedMask = APInt::getAllOnesValue(BitWidth);
- } else if (DemandedMask == 0) { // Not demanding any bits from V.
- if (V != UndefValue::get(VTy))
- return UpdateValueUsesWith(V, UndefValue::get(VTy));
- return false;
- } else if (Depth == 6) { // Limit search depth.
- return false;
+ if (DemandedMask == 0) { // Not demanding any bits from V.
+ if (isa<UndefValue>(V))
+ return 0;
+ return UndefValue::get(VTy);
}
+ if (Depth == 6) // Limit search depth.
+ return 0;
+
Instruction *I = dyn_cast<Instruction>(V);
- if (!I) return false; // Only analyze instructions.
-
+ if (!I) return 0; // Only analyze instructions.
+
APInt LHSKnownZero(BitWidth, 0), LHSKnownOne(BitWidth, 0);
APInt &RHSKnownZero = KnownZero, &RHSKnownOne = KnownOne;
+
+ // If there are multiple uses of this value and we aren't at the root, then
+ // we can't do any simplifications of the operands, because DemandedMask
+ // only reflects the bits demanded by *one* of the users.
+ if (Depth != 0 && !I->hasOneUse()) {
+ // Despite the fact that we can't simplify this instruction in all User's
+ // context, we can at least compute the knownzero/knownone bits, and we can
+ // do simplifications that apply to *just* the one user if we know that
+ // this instruction has a simpler value in that context.
+ if (I->getOpcode() == Instruction::And) {
+ // If either the LHS or the RHS are Zero, the result is zero.
+ ComputeMaskedBits(I->getOperand(1), DemandedMask,
+ RHSKnownZero, RHSKnownOne, Depth+1);
+ ComputeMaskedBits(I->getOperand(0), DemandedMask & ~RHSKnownZero,
+ LHSKnownZero, LHSKnownOne, Depth+1);
+
+ // If all of the demanded bits are known 1 on one side, return the other.
+ // These bits cannot contribute to the result of the 'and' in this
+ // context.
+ if ((DemandedMask & ~LHSKnownZero & RHSKnownOne) ==
+ (DemandedMask & ~LHSKnownZero))
+ return I->getOperand(0);
+ if ((DemandedMask & ~RHSKnownZero & LHSKnownOne) ==
+ (DemandedMask & ~RHSKnownZero))
+ return I->getOperand(1);
+
+ // If all of the demanded bits in the inputs are known zeros, return zero.
+ if ((DemandedMask & (RHSKnownZero|LHSKnownZero)) == DemandedMask)
+ return Constant::getNullValue(VTy);
+
+ } else if (I->getOpcode() == Instruction::Or) {
+ // We can simplify (X|Y) -> X or Y in the user's context if we know that
+ // only bits from X or Y are demanded.
+
+ // If either the LHS or the RHS are One, the result is One.
+ ComputeMaskedBits(I->getOperand(1), DemandedMask,
+ RHSKnownZero, RHSKnownOne, Depth+1);
+ ComputeMaskedBits(I->getOperand(0), DemandedMask & ~RHSKnownOne,
+ LHSKnownZero, LHSKnownOne, Depth+1);
+
+ // If all of the demanded bits are known zero on one side, return the
+ // other. These bits cannot contribute to the result of the 'or' in this
+ // context.
+ if ((DemandedMask & ~LHSKnownOne & RHSKnownZero) ==
+ (DemandedMask & ~LHSKnownOne))
+ return I->getOperand(0);
+ if ((DemandedMask & ~RHSKnownOne & LHSKnownZero) ==
+ (DemandedMask & ~RHSKnownOne))
+ return I->getOperand(1);
+
+ // If all of the potentially set bits on one side are known to be set on
+ // the other side, just use the 'other' side.
+ if ((DemandedMask & (~RHSKnownZero) & LHSKnownOne) ==
+ (DemandedMask & (~RHSKnownZero)))
+ return I->getOperand(0);
+ if ((DemandedMask & (~LHSKnownZero) & RHSKnownOne) ==
+ (DemandedMask & (~LHSKnownZero)))
+ return I->getOperand(1);
+ }
+
+ // Compute the KnownZero/KnownOne bits to simplify things downstream.
+ ComputeMaskedBits(I, DemandedMask, KnownZero, KnownOne, Depth);
+ return 0;
+ }
+
+ // If this is the root being simplified, allow it to have multiple uses,
+ // just set the DemandedMask to all bits so that we can try to simplify the
+ // operands. This allows visitTruncInst (for example) to simplify the
+ // operand of a trunc without duplicating all the logic below.
+ if (Depth == 0 && !V->hasOneUse())
+ DemandedMask = APInt::getAllOnesValue(BitWidth);
+
switch (I->getOpcode()) {
default:
- ComputeMaskedBits(V, DemandedMask, RHSKnownZero, RHSKnownOne, Depth);
+ ComputeMaskedBits(I, DemandedMask, RHSKnownZero, RHSKnownOne, Depth);
break;
case Instruction::And:
// If either the LHS or the RHS are Zero, the result is zero.
- if (SimplifyDemandedBits(I->getOperand(1), DemandedMask,
- RHSKnownZero, RHSKnownOne, Depth+1))
- return true;
- assert((RHSKnownZero & RHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
-
- // If something is known zero on the RHS, the bits aren't demanded on the
- // LHS.
- if (SimplifyDemandedBits(I->getOperand(0), DemandedMask & ~RHSKnownZero,
+ if (SimplifyDemandedBits(I->getOperandUse(1), DemandedMask,
+ RHSKnownZero, RHSKnownOne, Depth+1) ||
+ SimplifyDemandedBits(I->getOperandUse(0), DemandedMask & ~RHSKnownZero,
LHSKnownZero, LHSKnownOne, Depth+1))
- return true;
- assert((LHSKnownZero & LHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
+ return I;
+ assert(!(RHSKnownZero & RHSKnownOne) && "Bits known to be one AND zero?");
+ assert(!(LHSKnownZero & LHSKnownOne) && "Bits known to be one AND zero?");
// If all of the demanded bits are known 1 on one side, return the other.
// These bits cannot contribute to the result of the 'and'.
if ((DemandedMask & ~LHSKnownZero & RHSKnownOne) ==
(DemandedMask & ~LHSKnownZero))
- return UpdateValueUsesWith(I, I->getOperand(0));
+ return I->getOperand(0);
if ((DemandedMask & ~RHSKnownZero & LHSKnownOne) ==
(DemandedMask & ~RHSKnownZero))
- return UpdateValueUsesWith(I, I->getOperand(1));
+ return I->getOperand(1);
// If all of the demanded bits in the inputs are known zeros, return zero.
if ((DemandedMask & (RHSKnownZero|LHSKnownZero)) == DemandedMask)
- return UpdateValueUsesWith(I, Constant::getNullValue(VTy));
+ return Constant::getNullValue(VTy);
// If the RHS is a constant, see if we can simplify it.
if (ShrinkDemandedConstant(I, 1, DemandedMask & ~LHSKnownZero))
- return UpdateValueUsesWith(I, I);
+ return I;
// Output known-1 bits are only known if set in both the LHS & RHS.
RHSKnownOne &= LHSKnownOne;
break;
case Instruction::Or:
// If either the LHS or the RHS are One, the result is One.
- if (SimplifyDemandedBits(I->getOperand(1), DemandedMask,
- RHSKnownZero, RHSKnownOne, Depth+1))
- return true;
- assert((RHSKnownZero & RHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
- // If something is known one on the RHS, the bits aren't demanded on the
- // LHS.
- if (SimplifyDemandedBits(I->getOperand(0), DemandedMask & ~RHSKnownOne,
+ if (SimplifyDemandedBits(I->getOperandUse(1), DemandedMask,
+ RHSKnownZero, RHSKnownOne, Depth+1) ||
+ SimplifyDemandedBits(I->getOperandUse(0), DemandedMask & ~RHSKnownOne,
LHSKnownZero, LHSKnownOne, Depth+1))
- return true;
- assert((LHSKnownZero & LHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
+ return I;
+ assert(!(RHSKnownZero & RHSKnownOne) && "Bits known to be one AND zero?");
+ assert(!(LHSKnownZero & LHSKnownOne) && "Bits known to be one AND zero?");
// If all of the demanded bits are known zero on one side, return the other.
// These bits cannot contribute to the result of the 'or'.
if ((DemandedMask & ~LHSKnownOne & RHSKnownZero) ==
(DemandedMask & ~LHSKnownOne))
- return UpdateValueUsesWith(I, I->getOperand(0));
+ return I->getOperand(0);
if ((DemandedMask & ~RHSKnownOne & LHSKnownZero) ==
(DemandedMask & ~RHSKnownOne))
- return UpdateValueUsesWith(I, I->getOperand(1));
+ return I->getOperand(1);
// If all of the potentially set bits on one side are known to be set on
// the other side, just use the 'other' side.
if ((DemandedMask & (~RHSKnownZero) & LHSKnownOne) ==
(DemandedMask & (~RHSKnownZero)))
- return UpdateValueUsesWith(I, I->getOperand(0));
+ return I->getOperand(0);
if ((DemandedMask & (~LHSKnownZero) & RHSKnownOne) ==
(DemandedMask & (~LHSKnownZero)))
- return UpdateValueUsesWith(I, I->getOperand(1));
+ return I->getOperand(1);
// If the RHS is a constant, see if we can simplify it.
if (ShrinkDemandedConstant(I, 1, DemandedMask))
- return UpdateValueUsesWith(I, I);
+ return I;
// Output known-0 bits are only known if clear in both the LHS & RHS.
RHSKnownZero &= LHSKnownZero;
RHSKnownOne |= LHSKnownOne;
break;
case Instruction::Xor: {
- if (SimplifyDemandedBits(I->getOperand(1), DemandedMask,
- RHSKnownZero, RHSKnownOne, Depth+1))
- return true;
- assert((RHSKnownZero & RHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
- if (SimplifyDemandedBits(I->getOperand(0), DemandedMask,
+ if (SimplifyDemandedBits(I->getOperandUse(1), DemandedMask,
+ RHSKnownZero, RHSKnownOne, Depth+1) ||
+ SimplifyDemandedBits(I->getOperandUse(0), DemandedMask,
LHSKnownZero, LHSKnownOne, Depth+1))
- return true;
- assert((LHSKnownZero & LHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
+ return I;
+ assert(!(RHSKnownZero & RHSKnownOne) && "Bits known to be one AND zero?");
+ assert(!(LHSKnownZero & LHSKnownOne) && "Bits known to be one AND zero?");
// If all of the demanded bits are known zero on one side, return the other.
// These bits cannot contribute to the result of the 'xor'.
if ((DemandedMask & RHSKnownZero) == DemandedMask)
- return UpdateValueUsesWith(I, I->getOperand(0));
+ return I->getOperand(0);
if ((DemandedMask & LHSKnownZero) == DemandedMask)
- return UpdateValueUsesWith(I, I->getOperand(1));
+ return I->getOperand(1);
// Output known-0 bits are known if clear or set in both the LHS & RHS.
APInt KnownZeroOut = (RHSKnownZero & LHSKnownZero) |
Instruction *Or =
BinaryOperator::CreateOr(I->getOperand(0), I->getOperand(1),
I->getName());
- InsertNewInstBefore(Or, *I);
- return UpdateValueUsesWith(I, Or);
+ return InsertNewInstBefore(Or, *I);
}
// If all of the demanded bits on one side are known, and all of the set
Constant *AndC = ConstantInt::get(~RHSKnownOne & DemandedMask);
Instruction *And =
BinaryOperator::CreateAnd(I->getOperand(0), AndC, "tmp");
- InsertNewInstBefore(And, *I);
- return UpdateValueUsesWith(I, And);
+ return InsertNewInstBefore(And, *I);
}
}
// If the RHS is a constant, see if we can simplify it.
// FIXME: for XOR, we prefer to force bits to 1 if they will make a -1.
if (ShrinkDemandedConstant(I, 1, DemandedMask))
- return UpdateValueUsesWith(I, I);
+ return I;
RHSKnownZero = KnownZeroOut;
RHSKnownOne = KnownOneOut;
break;
}
case Instruction::Select:
- if (SimplifyDemandedBits(I->getOperand(2), DemandedMask,
- RHSKnownZero, RHSKnownOne, Depth+1))
- return true;
- if (SimplifyDemandedBits(I->getOperand(1), DemandedMask,
+ if (SimplifyDemandedBits(I->getOperandUse(2), DemandedMask,
+ RHSKnownZero, RHSKnownOne, Depth+1) ||
+ SimplifyDemandedBits(I->getOperandUse(1), DemandedMask,
LHSKnownZero, LHSKnownOne, Depth+1))
- return true;
- assert((RHSKnownZero & RHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
- assert((LHSKnownZero & LHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
+ return I;
+ assert(!(RHSKnownZero & RHSKnownOne) && "Bits known to be one AND zero?");
+ assert(!(LHSKnownZero & LHSKnownOne) && "Bits known to be one AND zero?");
// If the operands are constants, see if we can simplify them.
- if (ShrinkDemandedConstant(I, 1, DemandedMask))
- return UpdateValueUsesWith(I, I);
- if (ShrinkDemandedConstant(I, 2, DemandedMask))
- return UpdateValueUsesWith(I, I);
+ if (ShrinkDemandedConstant(I, 1, DemandedMask) ||
+ ShrinkDemandedConstant(I, 2, DemandedMask))
+ return I;
// Only known if known in both the LHS and RHS.
RHSKnownOne &= LHSKnownOne;
RHSKnownZero &= LHSKnownZero;
break;
case Instruction::Trunc: {
- uint32_t truncBf =
- cast<IntegerType>(I->getOperand(0)->getType())->getBitWidth();
+ unsigned truncBf = I->getOperand(0)->getType()->getPrimitiveSizeInBits();
DemandedMask.zext(truncBf);
RHSKnownZero.zext(truncBf);
RHSKnownOne.zext(truncBf);
- if (SimplifyDemandedBits(I->getOperand(0), DemandedMask,
+ if (SimplifyDemandedBits(I->getOperandUse(0), DemandedMask,
RHSKnownZero, RHSKnownOne, Depth+1))
- return true;
+ return I;
DemandedMask.trunc(BitWidth);
RHSKnownZero.trunc(BitWidth);
RHSKnownOne.trunc(BitWidth);
- assert((RHSKnownZero & RHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
+ assert(!(RHSKnownZero & RHSKnownOne) && "Bits known to be one AND zero?");
break;
}
case Instruction::BitCast:
if (!I->getOperand(0)->getType()->isInteger())
- return false;
-
- if (SimplifyDemandedBits(I->getOperand(0), DemandedMask,
+ return false; // vector->int or fp->int?
+ if (SimplifyDemandedBits(I->getOperandUse(0), DemandedMask,
RHSKnownZero, RHSKnownOne, Depth+1))
- return true;
- assert((RHSKnownZero & RHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
+ return I;
+ assert(!(RHSKnownZero & RHSKnownOne) && "Bits known to be one AND zero?");
break;
case Instruction::ZExt: {
// Compute the bits in the result that are not present in the input.
- const IntegerType *SrcTy = cast<IntegerType>(I->getOperand(0)->getType());
- uint32_t SrcBitWidth = SrcTy->getBitWidth();
+ unsigned SrcBitWidth =I->getOperand(0)->getType()->getPrimitiveSizeInBits();
DemandedMask.trunc(SrcBitWidth);
RHSKnownZero.trunc(SrcBitWidth);
RHSKnownOne.trunc(SrcBitWidth);
- if (SimplifyDemandedBits(I->getOperand(0), DemandedMask,
+ if (SimplifyDemandedBits(I->getOperandUse(0), DemandedMask,
RHSKnownZero, RHSKnownOne, Depth+1))
- return true;
+ return I;
DemandedMask.zext(BitWidth);
RHSKnownZero.zext(BitWidth);
RHSKnownOne.zext(BitWidth);
- assert((RHSKnownZero & RHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
+ assert(!(RHSKnownZero & RHSKnownOne) && "Bits known to be one AND zero?");
// The top bits are known to be zero.
RHSKnownZero |= APInt::getHighBitsSet(BitWidth, BitWidth - SrcBitWidth);
break;
}
case Instruction::SExt: {
// Compute the bits in the result that are not present in the input.
- const IntegerType *SrcTy = cast<IntegerType>(I->getOperand(0)->getType());
- uint32_t SrcBitWidth = SrcTy->getBitWidth();
+ unsigned SrcBitWidth =I->getOperand(0)->getType()->getPrimitiveSizeInBits();
APInt InputDemandedBits = DemandedMask &
APInt::getLowBitsSet(BitWidth, SrcBitWidth);
InputDemandedBits.trunc(SrcBitWidth);
RHSKnownZero.trunc(SrcBitWidth);
RHSKnownOne.trunc(SrcBitWidth);
- if (SimplifyDemandedBits(I->getOperand(0), InputDemandedBits,
+ if (SimplifyDemandedBits(I->getOperandUse(0), InputDemandedBits,
RHSKnownZero, RHSKnownOne, Depth+1))
- return true;
+ return I;
InputDemandedBits.zext(BitWidth);
RHSKnownZero.zext(BitWidth);
RHSKnownOne.zext(BitWidth);
- assert((RHSKnownZero & RHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
+ assert(!(RHSKnownZero & RHSKnownOne) && "Bits known to be one AND zero?");
// If the sign bit of the input is known set or clear, then we know the
// top bits of the result.
// If the input sign bit is known zero, or if the NewBits are not demanded
// convert this into a zero extension.
- if (RHSKnownZero[SrcBitWidth-1] || (NewBits & ~DemandedMask) == NewBits)
- {
+ if (RHSKnownZero[SrcBitWidth-1] || (NewBits & ~DemandedMask) == NewBits) {
// Convert to ZExt cast
- CastInst *NewCast = new ZExtInst(I->getOperand(0), VTy, I->getName(), I);
- return UpdateValueUsesWith(I, NewCast);
+ CastInst *NewCast = new ZExtInst(I->getOperand(0), VTy, I->getName());
+ return InsertNewInstBefore(NewCast, *I);
} else if (RHSKnownOne[SrcBitWidth-1]) { // Input sign bit known set
RHSKnownOne |= NewBits;
}
// Figure out what the input bits are. If the top bits of the and result
// are not demanded, then the add doesn't demand them from its input
// either.
- uint32_t NLZ = DemandedMask.countLeadingZeros();
+ unsigned NLZ = DemandedMask.countLeadingZeros();
// If there is a constant on the RHS, there are a variety of xformations
// we can do.
APInt InDemandedBits(APInt::getLowBitsSet(BitWidth, BitWidth - NLZ));
// Find information about known zero/one bits in the input.
- if (SimplifyDemandedBits(I->getOperand(0), InDemandedBits,
+ if (SimplifyDemandedBits(I->getOperandUse(0), InDemandedBits,
LHSKnownZero, LHSKnownOne, Depth+1))
- return true;
+ return I;
// If the RHS of the add has bits set that can't affect the input, reduce
// the constant.
if (ShrinkDemandedConstant(I, 1, InDemandedBits))
- return UpdateValueUsesWith(I, I);
+ return I;
// Avoid excess work.
if (LHSKnownZero == 0 && LHSKnownOne == 0)
Instruction *Or =
BinaryOperator::CreateOr(I->getOperand(0), I->getOperand(1),
I->getName());
- InsertNewInstBefore(Or, *I);
- return UpdateValueUsesWith(I, Or);
+ return InsertNewInstBefore(Or, *I);
}
// We can say something about the output known-zero and known-one bits,
// To compute this, we first compute the potential carry bits. These are
// the bits which may be modified. I'm not aware of a better way to do
// this scan.
- const APInt& RHSVal = RHS->getValue();
+ const APInt &RHSVal = RHS->getValue();
APInt CarryBits((~LHSKnownZero + RHSVal) ^ (~LHSKnownZero ^ RHSVal));
// Now that we know which bits have carries, compute the known-1/0 sets.
// Right fill the mask of bits for this ADD to demand the most
// significant bit and all those below it.
APInt DemandedFromOps(APInt::getLowBitsSet(BitWidth, BitWidth-NLZ));
- if (SimplifyDemandedBits(I->getOperand(0), DemandedFromOps,
- LHSKnownZero, LHSKnownOne, Depth+1))
- return true;
- if (SimplifyDemandedBits(I->getOperand(1), DemandedFromOps,
+ if (SimplifyDemandedBits(I->getOperandUse(0), DemandedFromOps,
+ LHSKnownZero, LHSKnownOne, Depth+1) ||
+ SimplifyDemandedBits(I->getOperandUse(1), DemandedFromOps,
LHSKnownZero, LHSKnownOne, Depth+1))
- return true;
+ return I;
}
}
break;
// significant bit and all those below it.
uint32_t NLZ = DemandedMask.countLeadingZeros();
APInt DemandedFromOps(APInt::getLowBitsSet(BitWidth, BitWidth-NLZ));
- if (SimplifyDemandedBits(I->getOperand(0), DemandedFromOps,
- LHSKnownZero, LHSKnownOne, Depth+1))
- return true;
- if (SimplifyDemandedBits(I->getOperand(1), DemandedFromOps,
+ if (SimplifyDemandedBits(I->getOperandUse(0), DemandedFromOps,
+ LHSKnownZero, LHSKnownOne, Depth+1) ||
+ SimplifyDemandedBits(I->getOperandUse(1), DemandedFromOps,
LHSKnownZero, LHSKnownOne, Depth+1))
- return true;
+ return I;
}
// Otherwise just hand the sub off to ComputeMaskedBits to fill in
// the known zeros and ones.
if (ConstantInt *SA = dyn_cast<ConstantInt>(I->getOperand(1))) {
uint64_t ShiftAmt = SA->getLimitedValue(BitWidth);
APInt DemandedMaskIn(DemandedMask.lshr(ShiftAmt));
- if (SimplifyDemandedBits(I->getOperand(0), DemandedMaskIn,
+ if (SimplifyDemandedBits(I->getOperandUse(0), DemandedMaskIn,
RHSKnownZero, RHSKnownOne, Depth+1))
- return true;
- assert((RHSKnownZero & RHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
+ return I;
+ assert(!(RHSKnownZero & RHSKnownOne) && "Bits known to be one AND zero?");
RHSKnownZero <<= ShiftAmt;
RHSKnownOne <<= ShiftAmt;
// low bits known zero.
// Unsigned shift right.
APInt DemandedMaskIn(DemandedMask.shl(ShiftAmt));
- if (SimplifyDemandedBits(I->getOperand(0), DemandedMaskIn,
+ if (SimplifyDemandedBits(I->getOperandUse(0), DemandedMaskIn,
RHSKnownZero, RHSKnownOne, Depth+1))
- return true;
- assert((RHSKnownZero & RHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
+ return I;
+ assert(!(RHSKnownZero & RHSKnownOne) && "Bits known to be one AND zero?");
RHSKnownZero = APIntOps::lshr(RHSKnownZero, ShiftAmt);
RHSKnownOne = APIntOps::lshr(RHSKnownOne, ShiftAmt);
if (ShiftAmt) {
// the shift amount is >= the size of the datatype, which is undefined.
if (DemandedMask == 1) {
// Perform the logical shift right.
- Value *NewVal = BinaryOperator::CreateLShr(
+ Instruction *NewVal = BinaryOperator::CreateLShr(
I->getOperand(0), I->getOperand(1), I->getName());
- InsertNewInstBefore(cast<Instruction>(NewVal), *I);
- return UpdateValueUsesWith(I, NewVal);
+ return InsertNewInstBefore(NewVal, *I);
}
// If the sign bit is the only bit demanded by this ashr, then there is no
// need to do it, the shift doesn't change the high bit.
if (DemandedMask.isSignBit())
- return UpdateValueUsesWith(I, I->getOperand(0));
+ return I->getOperand(0);
if (ConstantInt *SA = dyn_cast<ConstantInt>(I->getOperand(1))) {
uint32_t ShiftAmt = SA->getLimitedValue(BitWidth);
// demanded.
if (DemandedMask.countLeadingZeros() <= ShiftAmt)
DemandedMaskIn.set(BitWidth-1);
- if (SimplifyDemandedBits(I->getOperand(0),
- DemandedMaskIn,
+ if (SimplifyDemandedBits(I->getOperandUse(0), DemandedMaskIn,
RHSKnownZero, RHSKnownOne, Depth+1))
- return true;
- assert((RHSKnownZero & RHSKnownOne) == 0 &&
- "Bits known to be one AND zero?");
+ return I;
+ assert(!(RHSKnownZero & RHSKnownOne) && "Bits known to be one AND zero?");
// Compute the new bits that are at the top now.
APInt HighBits(APInt::getHighBitsSet(BitWidth, ShiftAmt));
RHSKnownZero = APIntOps::lshr(RHSKnownZero, ShiftAmt);
if (BitWidth <= ShiftAmt || RHSKnownZero[BitWidth-ShiftAmt-1] ||
(HighBits & ~DemandedMask) == HighBits) {
// Perform the logical shift right.
- Value *NewVal = BinaryOperator::CreateLShr(
+ Instruction *NewVal = BinaryOperator::CreateLShr(
I->getOperand(0), SA, I->getName());
- InsertNewInstBefore(cast<Instruction>(NewVal), *I);
- return UpdateValueUsesWith(I, NewVal);
+ return InsertNewInstBefore(NewVal, *I);
} else if ((RHSKnownOne & SignBit) != 0) { // New bits are known one.
RHSKnownOne |= HighBits;
}
APInt RA = Rem->getValue().abs();
if (RA.isPowerOf2()) {
if (DemandedMask.ule(RA)) // srem won't affect demanded bits
- return UpdateValueUsesWith(I, I->getOperand(0));
+ return I->getOperand(0);
APInt LowBits = RA - 1;
APInt Mask2 = LowBits | APInt::getSignBit(BitWidth);
- if (SimplifyDemandedBits(I->getOperand(0), Mask2,
+ if (SimplifyDemandedBits(I->getOperandUse(0), Mask2,
LHSKnownZero, LHSKnownOne, Depth+1))
- return true;
+ return I;
if (LHSKnownZero[BitWidth-1] || ((LHSKnownZero & LowBits) == LowBits))
LHSKnownZero |= ~LowBits;
KnownZero |= LHSKnownZero & DemandedMask;
- assert((KnownZero & KnownOne) == 0&&"Bits known to be one AND zero?");
+ assert(!(KnownZero & KnownOne) && "Bits known to be one AND zero?");
}
}
break;
case Instruction::URem: {
APInt KnownZero2(BitWidth, 0), KnownOne2(BitWidth, 0);
APInt AllOnes = APInt::getAllOnesValue(BitWidth);
- if (SimplifyDemandedBits(I->getOperand(0), AllOnes,
- KnownZero2, KnownOne2, Depth+1))
- return true;
-
- uint32_t Leaders = KnownZero2.countLeadingOnes();
- if (SimplifyDemandedBits(I->getOperand(1), AllOnes,
+ if (SimplifyDemandedBits(I->getOperandUse(0), AllOnes,
+ KnownZero2, KnownOne2, Depth+1) ||
+ SimplifyDemandedBits(I->getOperandUse(1), AllOnes,
KnownZero2, KnownOne2, Depth+1))
- return true;
+ return I;
+ unsigned Leaders = KnownZero2.countLeadingOnes();
Leaders = std::max(Leaders,
KnownZero2.countLeadingOnes());
KnownZero = APInt::getHighBitsSet(BitWidth, Leaders) & DemandedMask;
NewVal = BinaryOperator::CreateShl(I->getOperand(1),
ConstantInt::get(I->getType(), ResultBit-InputBit));
NewVal->takeName(I);
- InsertNewInstBefore(NewVal, *I);
- return UpdateValueUsesWith(I, NewVal);
+ return InsertNewInstBefore(NewVal, *I);
}
// TODO: Could compute known zero/one bits based on the input.
// If the client is only demanding bits that we know, return the known
// constant.
if ((DemandedMask & (RHSKnownZero|RHSKnownOne)) == DemandedMask)
- return UpdateValueUsesWith(I, ConstantInt::get(RHSKnownOne));
+ return ConstantInt::get(RHSKnownOne);
return false;
}
/// SimplifyDemandedVectorElts - The specified value produces a vector with
-/// 64 or fewer elements. DemandedElts contains the set of elements that are
+/// any number of elements. DemandedElts contains the set of elements that are
/// actually used by the caller. This method analyzes which elements of the
/// operand are undef and returns that information in UndefElts.
///
/// If the information about demanded elements can be used to simplify the
/// operation, the operation is simplified, then the resultant value is
/// returned. This returns null if no change was made.
-Value *InstCombiner::SimplifyDemandedVectorElts(Value *V, uint64_t DemandedElts,
- uint64_t &UndefElts,
+Value *InstCombiner::SimplifyDemandedVectorElts(Value *V, APInt DemandedElts,
+ APInt& UndefElts,
unsigned Depth) {
unsigned VWidth = cast<VectorType>(V->getType())->getNumElements();
- assert(VWidth <= 64 && "Vector too wide to analyze!");
- uint64_t EltMask = ~0ULL >> (64-VWidth);
+ APInt EltMask(APInt::getAllOnesValue(VWidth));
assert((DemandedElts & ~EltMask) == 0 && "Invalid DemandedElts!");
if (isa<UndefValue>(V)) {
std::vector<Constant*> Elts;
for (unsigned i = 0; i != VWidth; ++i)
- if (!(DemandedElts & (1ULL << i))) { // If not demanded, set to undef.
+ if (!DemandedElts[i]) { // If not demanded, set to undef.
Elts.push_back(Undef);
- UndefElts |= (1ULL << i);
+ UndefElts.set(i);
} else if (isa<UndefValue>(CP->getOperand(i))) { // Already undef.
Elts.push_back(Undef);
- UndefElts |= (1ULL << i);
+ UndefElts.set(i);
} else { // Otherwise, defined.
Elts.push_back(CP->getOperand(i));
}
Constant *Zero = Constant::getNullValue(EltTy);
Constant *Undef = UndefValue::get(EltTy);
std::vector<Constant*> Elts;
- for (unsigned i = 0; i != VWidth; ++i)
- Elts.push_back((DemandedElts & (1ULL << i)) ? Zero : Undef);
+ for (unsigned i = 0; i != VWidth; ++i) {
+ Constant *Elt = DemandedElts[i] ? Zero : Undef;
+ Elts.push_back(Elt);
+ }
UndefElts = DemandedElts ^ EltMask;
return ConstantVector::get(Elts);
}
if (!I) return false; // Only analyze instructions.
bool MadeChange = false;
- uint64_t UndefElts2;
+ APInt UndefElts2(VWidth, 0);
Value *TmpV;
switch (I->getOpcode()) {
default: break;
// If this is inserting an element that isn't demanded, remove this
// insertelement.
unsigned IdxNo = Idx->getZExtValue();
- if (IdxNo >= VWidth || (DemandedElts & (1ULL << IdxNo)) == 0)
+ if (IdxNo >= VWidth || !DemandedElts[IdxNo])
return AddSoonDeadInstToWorklist(*I, 0);
// Otherwise, the element inserted overwrites whatever was there, so the
// input demanded set is simpler than the output set.
- TmpV = SimplifyDemandedVectorElts(I->getOperand(0),
- DemandedElts & ~(1ULL << IdxNo),
+ APInt DemandedElts2 = DemandedElts;
+ DemandedElts2.clear(IdxNo);
+ TmpV = SimplifyDemandedVectorElts(I->getOperand(0), DemandedElts2,
UndefElts, Depth+1);
if (TmpV) { I->setOperand(0, TmpV); MadeChange = true; }
// The inserted element is defined.
- UndefElts &= ~(1ULL << IdxNo);
+ UndefElts.clear(IdxNo);
break;
}
case Instruction::ShuffleVector: {
ShuffleVectorInst *Shuffle = cast<ShuffleVectorInst>(I);
uint64_t LHSVWidth =
cast<VectorType>(Shuffle->getOperand(0)->getType())->getNumElements();
- uint64_t LeftDemanded = 0, RightDemanded = 0;
+ APInt LeftDemanded(LHSVWidth, 0), RightDemanded(LHSVWidth, 0);
for (unsigned i = 0; i < VWidth; i++) {
- if (DemandedElts & (1ULL << i)) {
+ if (DemandedElts[i]) {
unsigned MaskVal = Shuffle->getMaskValue(i);
if (MaskVal != -1u) {
assert(MaskVal < LHSVWidth * 2 &&
"shufflevector mask index out of range!");
if (MaskVal < LHSVWidth)
- LeftDemanded |= 1ULL << MaskVal;
+ LeftDemanded.set(MaskVal);
else
- RightDemanded |= 1ULL << (MaskVal - LHSVWidth);
+ RightDemanded.set(MaskVal - LHSVWidth);
}
}
}
+ APInt UndefElts4(LHSVWidth, 0);
TmpV = SimplifyDemandedVectorElts(I->getOperand(0), LeftDemanded,
- UndefElts2, Depth+1);
+ UndefElts4, Depth+1);
if (TmpV) { I->setOperand(0, TmpV); MadeChange = true; }
- uint64_t UndefElts3;
+ APInt UndefElts3(LHSVWidth, 0);
TmpV = SimplifyDemandedVectorElts(I->getOperand(1), RightDemanded,
UndefElts3, Depth+1);
if (TmpV) { I->setOperand(1, TmpV); MadeChange = true; }
for (unsigned i = 0; i < VWidth; i++) {
unsigned MaskVal = Shuffle->getMaskValue(i);
if (MaskVal == -1u) {
- uint64_t NewBit = 1ULL << i;
- UndefElts |= NewBit;
+ UndefElts.set(i);
} else if (MaskVal < LHSVWidth) {
- uint64_t NewBit = ((UndefElts2 >> MaskVal) & 1) << i;
- NewUndefElts |= NewBit;
- UndefElts |= NewBit;
+ if (UndefElts4[MaskVal]) {
+ NewUndefElts = true;
+ UndefElts.set(i);
+ }
} else {
- uint64_t NewBit = ((UndefElts3 >> (MaskVal - LHSVWidth)) & 1) << i;
- NewUndefElts |= NewBit;
- UndefElts |= NewBit;
+ if (UndefElts3[MaskVal - LHSVWidth]) {
+ NewUndefElts = true;
+ UndefElts.set(i);
+ }
}
}
// Add additional discovered undefs.
std::vector<Constant*> Elts;
for (unsigned i = 0; i < VWidth; ++i) {
- if (UndefElts & (1ULL << i))
+ if (UndefElts[i])
Elts.push_back(UndefValue::get(Type::Int32Ty));
else
Elts.push_back(ConstantInt::get(Type::Int32Ty,
const VectorType *VTy = dyn_cast<VectorType>(I->getOperand(0)->getType());
if (!VTy) break;
unsigned InVWidth = VTy->getNumElements();
- uint64_t InputDemandedElts = 0;
+ APInt InputDemandedElts(InVWidth, 0);
unsigned Ratio;
if (VWidth == InVWidth) {
// elements are live.
Ratio = VWidth/InVWidth;
for (unsigned OutIdx = 0; OutIdx != VWidth; ++OutIdx) {
- if (DemandedElts & (1ULL << OutIdx))
- InputDemandedElts |= 1ULL << (OutIdx/Ratio);
+ if (DemandedElts[OutIdx])
+ InputDemandedElts.set(OutIdx/Ratio);
}
} else {
// Untested so far.
// live.
Ratio = InVWidth/VWidth;
for (unsigned InIdx = 0; InIdx != InVWidth; ++InIdx)
- if (DemandedElts & (1ULL << InIdx/Ratio))
- InputDemandedElts |= 1ULL << InIdx;
+ if (DemandedElts[InIdx/Ratio])
+ InputDemandedElts.set(InIdx);
}
// div/rem demand all inputs, because they don't want divide by zero.
// then an output element is undef if the corresponding input element is
// undef.
for (unsigned OutIdx = 0; OutIdx != VWidth; ++OutIdx)
- if (UndefElts2 & (1ULL << (OutIdx/Ratio)))
- UndefElts |= 1ULL << OutIdx;
+ if (UndefElts2[OutIdx/Ratio])
+ UndefElts.set(OutIdx);
} else if (VWidth < InVWidth) {
assert(0 && "Unimp");
// If there are more elements in the source than there are in the result,
// elements are undef.
UndefElts = ~0ULL >> (64-VWidth); // Start out all undef.
for (unsigned InIdx = 0; InIdx != InVWidth; ++InIdx)
- if ((UndefElts2 & (1ULL << InIdx)) == 0) // Not undef?
- UndefElts &= ~(1ULL << (InIdx/Ratio)); // Clear undef bit.
+ if (!UndefElts2[InIdx]) // Not undef?
+ UndefElts.clear(InIdx/Ratio); // Clear undef bit.
}
break;
}
// See if SimplifyDemandedBits can simplify this. This handles stuff like
// (X & 254)+1 -> (X&254)|1
- if (!isa<VectorType>(I.getType())) {
- APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- if (SimplifyDemandedBits(&I, APInt::getAllOnesValue(BitWidth),
- KnownZero, KnownOne))
- return &I;
- }
+ if (!isa<VectorType>(I.getType()) && SimplifyDemandedInstructionBits(I))
+ return &I;
// zext(i1) - 1 -> select i1, 0, -1
if (ZExtInst *ZI = dyn_cast<ZExtInst>(LHS))
// sdiv X, -1 == -X
if (RHS->isAllOnesValue())
return BinaryOperator::CreateNeg(Op0);
-
- // -X/C -> X/-C, if and only if negation doesn't overflow.
- if (Value *LHSNeg = dyn_castNegVal(Op0)) {
- if (ConstantInt *CI = dyn_cast<ConstantInt>(LHSNeg)) {
- ConstantInt *RHSNeg = cast<ConstantInt>(ConstantExpr::getNeg(RHS));
- APInt RHSNegAPI(RHSNeg->getValue());
-
- APInt NegOne = -APInt(RHSNeg->getBitWidth(), 1, true);
- APInt TwoToExp(RHSNeg->getBitWidth(), 1 << (RHSNeg->getBitWidth() - 1));
-
- if ((RHS->getValue().isNegative() &&
- RHSNegAPI.slt(TwoToExp - 1)) ||
- (RHS->getValue().isNonNegative() &&
- RHSNegAPI.sgt(TwoToExp * NegOne))) {
- ConstantInt *CINeg = cast<ConstantInt>(ConstantExpr::getNeg(CI));
- APInt CINegAPI(CINeg->getValue());
-
- if ((CI->getValue().isNegative() && CINegAPI.slt(TwoToExp - 1)) ||
- (CI->getValue().isNonNegative() && CINegAPI.sgt(TwoToExp*NegOne)))
- return BinaryOperator::CreateSDiv(LHSNeg,
- ConstantExpr::getNeg(RHS));
- }
- }
- }
}
// If the sign bits of both operands are zero (i.e. we can prove they are
Instruction *InstCombiner::commonRemTransforms(BinaryOperator &I) {
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
- // 0 % X == 0 for integer, we don't need to preserve faults!
- if (Constant *LHS = dyn_cast<Constant>(Op0))
- if (LHS->isNullValue())
- return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
-
if (isa<UndefValue>(Op0)) { // undef % X -> 0
if (I.getType()->isFPOrFPVector())
return ReplaceInstUsesWith(I, Op0); // X % undef -> undef (could be SNaN)
if (Instruction *common = commonRemTransforms(I))
return common;
+ // 0 % X == 0 for integer, we don't need to preserve faults!
+ if (Constant *LHS = dyn_cast<Constant>(Op0))
+ if (LHS->isNullValue())
+ return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
+
if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
// X % 0 == undef, we don't need to preserve faults!
if (RHS->equalsInt(0))
}
// See if we can fold away this rem instruction.
- uint32_t BitWidth = cast<IntegerType>(I.getType())->getBitWidth();
- APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- if (SimplifyDemandedBits(&I, APInt::getAllOnesValue(BitWidth),
- KnownZero, KnownOne))
+ if (SimplifyDemandedInstructionBits(I))
return &I;
}
}
}
}
+ // If it's a constant vector, flip any negative values positive.
+ if (ConstantVector *RHSV = dyn_cast<ConstantVector>(Op1)) {
+ unsigned VWidth = RHSV->getNumOperands();
+
+ bool hasNegative = false;
+ for (unsigned i = 0; !hasNegative && i != VWidth; ++i)
+ if (ConstantInt *RHS = dyn_cast<ConstantInt>(RHSV->getOperand(i)))
+ if (RHS->getValue().isNegative())
+ hasNegative = true;
+
+ if (hasNegative) {
+ std::vector<Constant *> Elts(VWidth);
+ for (unsigned i = 0; i != VWidth; ++i) {
+ if (ConstantInt *RHS = dyn_cast<ConstantInt>(RHSV->getOperand(i))) {
+ if (RHS->getValue().isNegative())
+ Elts[i] = cast<ConstantInt>(ConstantExpr::getNeg(RHS));
+ else
+ Elts[i] = RHS;
+ }
+ }
+
+ Constant *NewRHSV = ConstantVector::get(Elts);
+ if (NewRHSV != RHSV) {
+ AddUsesToWorkList(I);
+ I.setOperand(1, NewRHSV);
+ return &I;
+ }
+ }
+ }
+
return 0;
}
// See if we can simplify any instructions used by the instruction whose sole
// purpose is to compute bits we don't care about.
if (!isa<VectorType>(I.getType())) {
- uint32_t BitWidth = cast<IntegerType>(I.getType())->getBitWidth();
- APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- if (SimplifyDemandedBits(&I, APInt::getAllOnesValue(BitWidth),
- KnownZero, KnownOne))
+ if (SimplifyDemandedInstructionBits(I))
return &I;
} else {
if (ConstantVector *CP = dyn_cast<ConstantVector>(Op1)) {
Value *C, Value *D) {
// If A is not a select of -1/0, this cannot match.
Value *Cond = 0;
- if (!match(A, m_SelectCst(m_Value(Cond), -1, 0)))
+ if (!match(A, m_SelectCst<-1, 0>(m_Value(Cond))))
return 0;
// ((cond?-1:0)&C) | (B&(cond?0:-1)) -> cond ? C : B.
- if (match(D, m_SelectCst(m_Specific(Cond), 0, -1)))
+ if (match(D, m_SelectCst<0, -1>(m_Specific(Cond))))
return SelectInst::Create(Cond, C, B);
- if (match(D, m_Not(m_SelectCst(m_Specific(Cond), -1, 0))))
+ if (match(D, m_Not(m_SelectCst<-1, 0>(m_Specific(Cond)))))
return SelectInst::Create(Cond, C, B);
// ((cond?-1:0)&C) | ((cond?0:-1)&D) -> cond ? C : D.
- if (match(B, m_SelectCst(m_Specific(Cond), 0, -1)))
+ if (match(B, m_SelectCst<0, -1>(m_Specific(Cond))))
return SelectInst::Create(Cond, C, D);
- if (match(B, m_Not(m_SelectCst(m_Specific(Cond), -1, 0))))
+ if (match(B, m_Not(m_SelectCst<-1, 0>(m_Specific(Cond)))))
return SelectInst::Create(Cond, C, D);
return 0;
}
/// FoldOrWithConstants - This helper function folds:
///
-/// ((A|B)&1)|(B&-2)
+/// ((A | B) & C1) | (B & C2)
///
/// into:
///
-/// (A&1) | B
-Instruction *InstCombiner::FoldOrWithConstants(BinaryOperator &I,
+/// (A & C1) | B
+///
+/// when the XOR of the two constants is "all ones" (-1).
+Instruction *InstCombiner::FoldOrWithConstants(BinaryOperator &I, Value *Op,
Value *A, Value *B, Value *C) {
- Value *Op1 = I.getOperand(1);
+ ConstantInt *CI1 = dyn_cast<ConstantInt>(C);
+ if (!CI1) return 0;
- if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) {
- if (CI->getValue() == 1) {
- Value *V1 = 0, *C2 = 0;
- if (match(Op1, m_And(m_Value(V1), m_Value(C2)))) {
- ConstantInt *CI2 = dyn_cast<ConstantInt>(C2);
+ Value *V1 = 0;
+ ConstantInt *CI2 = 0;
+ if (!match(Op, m_And(m_Value(V1), m_ConstantInt(CI2)))) return 0;
- if (!CI2) {
- std::swap(V1, C2);
- CI2 = dyn_cast<ConstantInt>(C2);
- }
+ APInt Xor = CI1->getValue() ^ CI2->getValue();
+ if (!Xor.isAllOnesValue()) return 0;
- if (CI2) {
- APInt NegTwo = -APInt(CI2->getValue().getBitWidth(), 2, true);
- if (CI2->getValue().eq(NegTwo)) {
- if (V1 == B) {
- Instruction *NewOp =
- InsertNewInstBefore(BinaryOperator::CreateAnd(A, CI), I);
- return BinaryOperator::CreateOr(NewOp, B);
- }
- if (V1 == A) {
- Instruction *NewOp =
- InsertNewInstBefore(BinaryOperator::CreateAnd(B, CI), I);
- return BinaryOperator::CreateOr(NewOp, A);
- }
- }
- }
- }
- }
+ if (V1 == A || V1 == B) {
+ Instruction *NewOp =
+ InsertNewInstBefore(BinaryOperator::CreateAnd((V1 == A) ? B : A, CI1), I);
+ return BinaryOperator::CreateOr(NewOp, V1);
}
return 0;
// See if we can simplify any instructions used by the instruction whose sole
// purpose is to compute bits we don't care about.
if (!isa<VectorType>(I.getType())) {
- uint32_t BitWidth = cast<IntegerType>(I.getType())->getBitWidth();
- APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- if (SimplifyDemandedBits(&I, APInt::getAllOnesValue(BitWidth),
- KnownZero, KnownOne))
+ if (SimplifyDemandedInstructionBits(I))
return &I;
} else if (isa<ConstantAggregateZero>(Op1)) {
return ReplaceInstUsesWith(I, Op0); // X | <0,0> -> X
// ((A|B)&1)|(B&-2) -> (A&1) | B
if (match(Op0, m_And(m_Or(m_Value(A), m_Value(B)), m_Value(C))) ||
match(Op0, m_And(m_Value(C), m_Or(m_Value(A), m_Value(B))))) {
- Instruction *Ret = FoldOrWithConstants(I, A, B, C);
+ Instruction *Ret = FoldOrWithConstants(I, Op1, A, B, C);
if (Ret) return Ret;
}
// (B&-2)|((A|B)&1) -> (A&1) | B
if (match(Op1, m_And(m_Or(m_Value(A), m_Value(B)), m_Value(C))) ||
match(Op1, m_And(m_Value(C), m_Or(m_Value(A), m_Value(B))))) {
- Instruction *Ret = FoldOrWithConstants(I, A, B, C);
+ Instruction *Ret = FoldOrWithConstants(I, Op0, A, B, C);
if (Ret) return Ret;
}
// See if we can simplify any instructions used by the instruction whose sole
// purpose is to compute bits we don't care about.
if (!isa<VectorType>(I.getType())) {
- uint32_t BitWidth = cast<IntegerType>(I.getType())->getBitWidth();
- APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- if (SimplifyDemandedBits(&I, APInt::getAllOnesValue(BitWidth),
- KnownZero, KnownOne))
+ if (SimplifyDemandedInstructionBits(I))
return &I;
} else if (isa<ConstantAggregateZero>(Op1)) {
return ReplaceInstUsesWith(I, Op0); // X ^ <0,0> -> X
if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
- // xor (cmp A, B), true = not (cmp A, B) = !cmp A, B
if (RHS == ConstantInt::getTrue() && Op0->hasOneUse()) {
+ // xor (cmp A, B), true = not (cmp A, B) = !cmp A, B
if (ICmpInst *ICI = dyn_cast<ICmpInst>(Op0))
return new ICmpInst(ICI->getInversePredicate(),
ICI->getOperand(0), ICI->getOperand(1));
for (User::op_iterator i = GEP->op_begin() + 1, e = GEP->op_end(); i != e;
++i, ++GTI) {
Value *Op = *i;
- uint64_t Size = TD.getABITypeSize(GTI.getIndexedType()) & PtrSizeMask;
+ uint64_t Size = TD.getTypePaddedSize(GTI.getIndexedType()) & PtrSizeMask;
if (ConstantInt *OpC = dyn_cast<ConstantInt>(Op)) {
if (OpC->isZero()) continue;
if (const StructType *STy = dyn_cast<StructType>(*GTI)) {
Offset += TD.getStructLayout(STy)->getElementOffset(CI->getZExtValue());
} else {
- uint64_t Size = TD.getABITypeSize(GTI.getIndexedType());
+ uint64_t Size = TD.getTypePaddedSize(GTI.getIndexedType());
Offset += Size*CI->getSExtValue();
}
} else {
Value *VariableIdx = GEP->getOperand(i);
// Determine the scale factor of the variable element. For example, this is
// 4 if the variable index is into an array of i32.
- uint64_t VariableScale = TD.getABITypeSize(GTI.getIndexedType());
+ uint64_t VariableScale = TD.getTypePaddedSize(GTI.getIndexedType());
// Verify that there are no other variable indices. If so, emit the hard way.
for (++i, ++GTI; i != e; ++i, ++GTI) {
if (const StructType *STy = dyn_cast<StructType>(*GTI)) {
Offset += TD.getStructLayout(STy)->getElementOffset(CI->getZExtValue());
} else {
- uint64_t Size = TD.getABITypeSize(GTI.getIndexedType());
+ uint64_t Size = TD.getTypePaddedSize(GTI.getIndexedType());
Offset += Size*CI->getSExtValue();
}
}
// See if we are doing a comparison with a constant.
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
- Value *A, *B;
+ Value *A = 0, *B = 0;
// (icmp ne/eq (sub A B) 0) -> (icmp ne/eq A, B)
if (I.isEquality() && CI->isNullValue() &&
bool UnusedBit;
bool isSignBit = isSignBitCheck(I.getPredicate(), CI, UnusedBit);
- if (SimplifyDemandedBits(Op0,
+ if (SimplifyDemandedBits(I.getOperandUse(0),
isSignBit ? APInt::getSignBit(BitWidth)
: APInt::getAllOnesValue(BitWidth),
KnownZero, KnownOne, 0))
if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
if (BinaryOperator *Op1I = dyn_cast<BinaryOperator>(Op1)) {
if (Op0I->getOpcode() == Op1I->getOpcode() && Op0I->hasOneUse() &&
- Op1I->hasOneUse() && Op0I->getOperand(1) == Op1I->getOperand(1) &&
- I.isEquality()) {
+ Op1I->hasOneUse() && Op0I->getOperand(1) == Op1I->getOperand(1)) {
switch (Op0I->getOpcode()) {
default: break;
case Instruction::Add:
case Instruction::Sub:
case Instruction::Xor:
- // a+x icmp eq/ne b+x --> a icmp b
- return new ICmpInst(I.getPredicate(), Op0I->getOperand(0),
- Op1I->getOperand(0));
+ if (I.isEquality()) // a+x icmp eq/ne b+x --> a icmp b
+ return new ICmpInst(I.getPredicate(), Op0I->getOperand(0),
+ Op1I->getOperand(0));
+ // icmp u/s (a ^ signbit), (b ^ signbit) --> icmp s/u a, b
+ if (ConstantInt *CI = dyn_cast<ConstantInt>(Op0I->getOperand(1))) {
+ if (CI->getValue().isSignBit()) {
+ ICmpInst::Predicate Pred = I.isSignedPredicate()
+ ? I.getUnsignedPredicate()
+ : I.getSignedPredicate();
+ return new ICmpInst(Pred, Op0I->getOperand(0),
+ Op1I->getOperand(0));
+ }
+
+ if (CI->getValue().isMaxSignedValue()) {
+ ICmpInst::Predicate Pred = I.isSignedPredicate()
+ ? I.getUnsignedPredicate()
+ : I.getSignedPredicate();
+ Pred = I.getSwappedPredicate(Pred);
+ return new ICmpInst(Pred, Op0I->getOperand(0),
+ Op1I->getOperand(0));
+ }
+ }
break;
case Instruction::Mul:
+ if (!I.isEquality())
+ break;
+
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op0I->getOperand(1))) {
// a * Cst icmp eq/ne b * Cst --> a & Mask icmp b & Mask
// Mask = -1 >> count-trailing-zeros(Cst).
const APInt &RHSV = RHS->getValue();
switch (LHSI->getOpcode()) {
+ case Instruction::Trunc:
+ if (ICI.isEquality() && LHSI->hasOneUse()) {
+ // Simplify icmp eq (trunc x to i8), 42 -> icmp eq x, 42|highbits if all
+ // of the high bits truncated out of x are known.
+ unsigned DstBits = LHSI->getType()->getPrimitiveSizeInBits(),
+ SrcBits = LHSI->getOperand(0)->getType()->getPrimitiveSizeInBits();
+ APInt Mask(APInt::getHighBitsSet(SrcBits, SrcBits-DstBits));
+ APInt KnownZero(SrcBits, 0), KnownOne(SrcBits, 0);
+ ComputeMaskedBits(LHSI->getOperand(0), Mask, KnownZero, KnownOne);
+
+ // If all the high bits are known, we can do this xform.
+ if ((KnownZero|KnownOne).countLeadingOnes() >= SrcBits-DstBits) {
+ // Pull in the high bits from known-ones set.
+ APInt NewRHS(RHS->getValue());
+ NewRHS.zext(SrcBits);
+ NewRHS |= KnownOne;
+ return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0),
+ ConstantInt::get(NewRHS));
+ }
+ }
+ break;
+
case Instruction::Xor: // (icmp pred (xor X, XorCST), CI)
if (ConstantInt *XorCST = dyn_cast<ConstantInt>(LHSI->getOperand(1))) {
// If this is a comparison that tests the signbit (X < 0) or (x > -1),
else
return new ICmpInst(ICmpInst::ICMP_SLT, CompareVal, AddOne(RHS));
}
+
+ if (LHSI->hasOneUse()) {
+ // (icmp u/s (xor A SignBit), C) -> (icmp s/u A, (xor C SignBit))
+ if (!ICI.isEquality() && XorCST->getValue().isSignBit()) {
+ const APInt &SignBit = XorCST->getValue();
+ ICmpInst::Predicate Pred = ICI.isSignedPredicate()
+ ? ICI.getUnsignedPredicate()
+ : ICI.getSignedPredicate();
+ return new ICmpInst(Pred, LHSI->getOperand(0),
+ ConstantInt::get(RHSV ^ SignBit));
+ }
+
+ // (icmp u/s (xor A ~SignBit), C) -> (icmp s/u (xor C ~SignBit), A)
+ if (!ICI.isEquality() && XorCST->getValue().isMaxSignedValue()) {
+ const APInt &NotSignBit = XorCST->getValue();
+ ICmpInst::Predicate Pred = ICI.isSignedPredicate()
+ ? ICI.getUnsignedPredicate()
+ : ICI.getSignedPredicate();
+ Pred = ICI.getSwappedPredicate(Pred);
+ return new ICmpInst(Pred, LHSI->getOperand(0),
+ ConstantInt::get(RHSV ^ NotSignBit));
+ }
+ }
}
break;
case Instruction::And: // (icmp pred (and X, AndCST), RHS)
return &ICI;
}
}
- } else { // Not a ICMP_EQ/ICMP_NE
- // If the LHS is a cast from an integral value of the same size,
- // then since we know the RHS is a constant, try to simlify.
- if (CastInst *Cast = dyn_cast<CastInst>(LHSI)) {
- Value *CastOp = Cast->getOperand(0);
- const Type *SrcTy = CastOp->getType();
- uint32_t SrcTySize = SrcTy->getPrimitiveSizeInBits();
- if (SrcTy->isInteger() &&
- SrcTySize == Cast->getType()->getPrimitiveSizeInBits()) {
- // If this is an unsigned comparison, try to make the comparison use
- // smaller constant values.
- if (ICI.getPredicate() == ICmpInst::ICMP_ULT && RHSV.isSignBit()) {
- // X u< 128 => X s> -1
- return new ICmpInst(ICmpInst::ICMP_SGT, CastOp,
- ConstantInt::get(APInt::getAllOnesValue(SrcTySize)));
- } else if (ICI.getPredicate() == ICmpInst::ICMP_UGT &&
- RHSV == APInt::getSignedMaxValue(SrcTySize)) {
- // X u> 127 => X s< 0
- return new ICmpInst(ICmpInst::ICMP_SLT, CastOp,
- Constant::getNullValue(SrcTy));
- }
- }
- }
}
return 0;
}
MaskedValueIsZero(Op0,
APInt::getSignBit(I.getType()->getPrimitiveSizeInBits())))
return BinaryOperator::CreateLShr(Op0, I.getOperand(1));
-
+
+ // Arithmetic shifting an all-sign-bit value is a no-op.
+ unsigned NumSignBits = ComputeNumSignBits(Op0);
+ if (NumSignBits == Op0->getType()->getPrimitiveSizeInBits())
+ return ReplaceInstUsesWith(I, Op0);
+
return 0;
}
Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
BinaryOperator &I) {
- bool isLeftShift = I.getOpcode() == Instruction::Shl;
+ bool isLeftShift = I.getOpcode() == Instruction::Shl;
// See if we can simplify any instructions used by the instruction whose sole
// purpose is to compute bits we don't care about.
uint32_t TypeBits = Op0->getType()->getPrimitiveSizeInBits();
- APInt KnownZero(TypeBits, 0), KnownOne(TypeBits, 0);
- if (SimplifyDemandedBits(&I, APInt::getAllOnesValue(TypeBits),
- KnownZero, KnownOne))
+ if (SimplifyDemandedInstructionBits(I))
return &I;
// shl uint X, 32 = 0 and shr ubyte Y, 9 = 0, ... just don't eliminate shr
// same, we open the door to infinite loops of various kinds.
if (!AI.hasOneUse() && CastElTyAlign == AllocElTyAlign) return 0;
- uint64_t AllocElTySize = TD->getABITypeSize(AllocElTy);
- uint64_t CastElTySize = TD->getABITypeSize(CastElTy);
+ uint64_t AllocElTySize = TD->getTypePaddedSize(AllocElTy);
+ uint64_t CastElTySize = TD->getTypePaddedSize(CastElTy);
if (CastElTySize == 0 || AllocElTySize == 0) return 0;
// See if we can satisfy the modulus by pulling a scale out of the array
/// the final result.
bool InstCombiner::CanEvaluateInDifferentType(Value *V, const IntegerType *Ty,
unsigned CastOpc,
- int &NumCastsRemoved) {
+ int &NumCastsRemoved){
// We can always evaluate constants in another type.
if (isa<ConstantInt>(V))
return true;
// require duplicating the instruction in general, which isn't profitable.
if (!I->hasOneUse()) return false;
- switch (I->getOpcode()) {
+ unsigned Opc = I->getOpcode();
+ switch (Opc) {
case Instruction::Add:
case Instruction::Sub:
case Instruction::Mul:
// If this is the same kind of case as our original (e.g. zext+zext), we
// can safely replace it. Note that replacing it does not reduce the number
// of casts in the input.
- if (I->getOpcode() == CastOpc)
+ if (Opc == CastOpc)
+ return true;
+
+ // sext (zext ty1), ty2 -> zext ty2
+ if (CastOpc == Instruction::SExt && Opc == Instruction::ZExt)
return true;
break;
case Instruction::Select: {
// Otherwise, it must be an instruction.
Instruction *I = cast<Instruction>(V);
Instruction *Res = 0;
- switch (I->getOpcode()) {
+ unsigned Opc = I->getOpcode();
+ switch (Opc) {
case Instruction::Add:
case Instruction::Sub:
case Instruction::Mul:
case Instruction::Shl: {
Value *LHS = EvaluateInDifferentType(I->getOperand(0), Ty, isSigned);
Value *RHS = EvaluateInDifferentType(I->getOperand(1), Ty, isSigned);
- Res = BinaryOperator::Create((Instruction::BinaryOps)I->getOpcode(),
- LHS, RHS);
+ Res = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
break;
}
case Instruction::Trunc:
return 0;
}
+/// FindElementAtOffset - Given a type and a constant offset, determine whether
+/// or not there is a sequence of GEP indices into the type that will land us at
+/// the specified offset. If so, fill them into NewIndices and return the
+/// resultant element type, otherwise return null.
+static const Type *FindElementAtOffset(const Type *Ty, int64_t Offset,
+ SmallVectorImpl<Value*> &NewIndices,
+ const TargetData *TD) {
+ if (!Ty->isSized()) return 0;
+
+ // Start with the index over the outer type. Note that the type size
+ // might be zero (even if the offset isn't zero) if the indexed type
+ // is something like [0 x {int, int}]
+ const Type *IntPtrTy = TD->getIntPtrType();
+ int64_t FirstIdx = 0;
+ if (int64_t TySize = TD->getTypePaddedSize(Ty)) {
+ FirstIdx = Offset/TySize;
+ Offset -= FirstIdx*TySize;
+
+ // Handle hosts where % returns negative instead of values [0..TySize).
+ if (Offset < 0) {
+ --FirstIdx;
+ Offset += TySize;
+ assert(Offset >= 0);
+ }
+ assert((uint64_t)Offset < (uint64_t)TySize && "Out of range offset");
+ }
+
+ NewIndices.push_back(ConstantInt::get(IntPtrTy, FirstIdx));
+
+ // Index into the types. If we fail, set OrigBase to null.
+ while (Offset) {
+ // Indexing into tail padding between struct/array elements.
+ if (uint64_t(Offset*8) >= TD->getTypeSizeInBits(Ty))
+ return 0;
+
+ if (const StructType *STy = dyn_cast<StructType>(Ty)) {
+ const StructLayout *SL = TD->getStructLayout(STy);
+ assert(Offset < (int64_t)SL->getSizeInBytes() &&
+ "Offset must stay within the indexed type");
+
+ unsigned Elt = SL->getElementContainingOffset(Offset);
+ NewIndices.push_back(ConstantInt::get(Type::Int32Ty, Elt));
+
+ Offset -= SL->getElementOffset(Elt);
+ Ty = STy->getElementType(Elt);
+ } else if (const ArrayType *AT = dyn_cast<ArrayType>(Ty)) {
+ uint64_t EltSize = TD->getTypePaddedSize(AT->getElementType());
+ assert(EltSize && "Cannot index into a zero-sized array");
+ NewIndices.push_back(ConstantInt::get(IntPtrTy,Offset/EltSize));
+ Offset %= EltSize;
+ Ty = AT->getElementType();
+ } else {
+ // Otherwise, we can't index into the middle of this atomic type, bail.
+ return 0;
+ }
+ }
+
+ return Ty;
+}
+
/// @brief Implement the transforms for cast of pointer (bitcast/ptrtoint)
Instruction *InstCombiner::commonPointerCastTransforms(CastInst &CI) {
Value *Src = CI.getOperand(0);
Value *OrigBase = cast<BitCastInst>(GEP->getOperand(0))->getOperand(0);
const Type *GEPIdxTy =
cast<PointerType>(OrigBase->getType())->getElementType();
- if (GEPIdxTy->isSized()) {
- SmallVector<Value*, 8> NewIndices;
-
- // Start with the index over the outer type. Note that the type size
- // might be zero (even if the offset isn't zero) if the indexed type
- // is something like [0 x {int, int}]
- const Type *IntPtrTy = TD->getIntPtrType();
- int64_t FirstIdx = 0;
- if (int64_t TySize = TD->getABITypeSize(GEPIdxTy)) {
- FirstIdx = Offset/TySize;
- Offset %= TySize;
-
- // Handle silly modulus not returning values values [0..TySize).
- if (Offset < 0) {
- --FirstIdx;
- Offset += TySize;
- assert(Offset >= 0);
- }
- assert((uint64_t)Offset < (uint64_t)TySize &&"Out of range offset");
- }
+ SmallVector<Value*, 8> NewIndices;
+ if (FindElementAtOffset(GEPIdxTy, Offset, NewIndices, TD)) {
+ // If we were able to index down into an element, create the GEP
+ // and bitcast the result. This eliminates one bitcast, potentially
+ // two.
+ Instruction *NGEP = GetElementPtrInst::Create(OrigBase,
+ NewIndices.begin(),
+ NewIndices.end(), "");
+ InsertNewInstBefore(NGEP, CI);
+ NGEP->takeName(GEP);
- NewIndices.push_back(ConstantInt::get(IntPtrTy, FirstIdx));
-
- // Index into the types. If we fail, set OrigBase to null.
- while (Offset) {
- if (const StructType *STy = dyn_cast<StructType>(GEPIdxTy)) {
- const StructLayout *SL = TD->getStructLayout(STy);
- if (Offset < (int64_t)SL->getSizeInBytes()) {
- unsigned Elt = SL->getElementContainingOffset(Offset);
- NewIndices.push_back(ConstantInt::get(Type::Int32Ty, Elt));
-
- Offset -= SL->getElementOffset(Elt);
- GEPIdxTy = STy->getElementType(Elt);
- } else {
- // Otherwise, we can't index into this, bail out.
- Offset = 0;
- OrigBase = 0;
- }
- } else if (isa<ArrayType>(GEPIdxTy) || isa<VectorType>(GEPIdxTy)) {
- const SequentialType *STy = cast<SequentialType>(GEPIdxTy);
- if (uint64_t EltSize = TD->getABITypeSize(STy->getElementType())){
- NewIndices.push_back(ConstantInt::get(IntPtrTy,Offset/EltSize));
- Offset %= EltSize;
- } else {
- NewIndices.push_back(ConstantInt::get(IntPtrTy, 0));
- }
- GEPIdxTy = STy->getElementType();
- } else {
- // Otherwise, we can't index into this, bail out.
- Offset = 0;
- OrigBase = 0;
- }
- }
- if (OrigBase) {
- // If we were able to index down into an element, create the GEP
- // and bitcast the result. This eliminates one bitcast, potentially
- // two.
- Instruction *NGEP = GetElementPtrInst::Create(OrigBase,
- NewIndices.begin(),
- NewIndices.end(), "");
- InsertNewInstBefore(NGEP, CI);
- NGEP->takeName(GEP);
-
- if (isa<BitCastInst>(CI))
- return new BitCastInst(NGEP, CI.getType());
- assert(isa<PtrToIntInst>(CI));
- return new PtrToIntInst(NGEP, CI.getType());
- }
+ if (isa<BitCastInst>(CI))
+ return new BitCastInst(NGEP, CI.getType());
+ assert(isa<PtrToIntInst>(CI));
+ return new PtrToIntInst(NGEP, CI.getType());
}
}
}
}
-
/// Only the TRUNC, ZEXT, SEXT, and BITCAST can both operand and result as
/// integer types. This function implements the common transforms for all those
/// cases.
// See if we can simplify any instructions used by the LHS whose sole
// purpose is to compute bits we don't care about.
- APInt KnownZero(DestBitSize, 0), KnownOne(DestBitSize, 0);
- if (SimplifyDemandedBits(&CI, APInt::getAllOnesValue(DestBitSize),
- KnownZero, KnownOne))
+ if (SimplifyDemandedInstructionBits(CI))
return &CI;
// If the source isn't an instruction or has more than one use then we
// so we require that the input have eliminated at least one cast. If this
// is a sign extension, we insert two new casts (to do the extension) so we
// require that two casts have been eliminated.
- bool DoXForm;
+ bool DoXForm = false;
+ bool JustReplace = false;
switch (CI.getOpcode()) {
default:
// All the others use floating point so we shouldn't actually
case Instruction::Trunc:
DoXForm = true;
break;
- case Instruction::ZExt:
+ case Instruction::ZExt: {
DoXForm = NumCastsRemoved >= 1;
+ if (!DoXForm && 0) {
+ // If it's unnecessary to issue an AND to clear the high bits, it's
+ // always profitable to do this xform.
+ Value *TryRes = EvaluateInDifferentType(SrcI, DestTy, false);
+ APInt Mask(APInt::getBitsSet(DestBitSize, SrcBitSize, DestBitSize));
+ if (MaskedValueIsZero(TryRes, Mask))
+ return ReplaceInstUsesWith(CI, TryRes);
+
+ if (Instruction *TryI = dyn_cast<Instruction>(TryRes))
+ if (TryI->use_empty())
+ EraseInstFromFunction(*TryI);
+ }
break;
- case Instruction::SExt:
+ }
+ case Instruction::SExt: {
DoXForm = NumCastsRemoved >= 2;
+ if (!DoXForm && !isa<TruncInst>(SrcI) && 0) {
+ // If we do not have to emit the truncate + sext pair, then it's always
+ // profitable to do this xform.
+ //
+ // It's not safe to eliminate the trunc + sext pair if one of the
+ // eliminated cast is a truncate. e.g.
+ // t2 = trunc i32 t1 to i16
+ // t3 = sext i16 t2 to i32
+ // !=
+ // i32 t1
+ Value *TryRes = EvaluateInDifferentType(SrcI, DestTy, true);
+ unsigned NumSignBits = ComputeNumSignBits(TryRes);
+ if (NumSignBits > (DestBitSize - SrcBitSize))
+ return ReplaceInstUsesWith(CI, TryRes);
+
+ if (Instruction *TryI = dyn_cast<Instruction>(TryRes))
+ if (TryI->use_empty())
+ EraseInstFromFunction(*TryI);
+ }
break;
}
+ }
if (DoXForm) {
+ DOUT << "ICE: EvaluateInDifferentType converting expression type to avoid"
+ << " cast: " << CI;
Value *Res = EvaluateInDifferentType(SrcI, DestTy,
CI.getOpcode() == Instruction::SExt);
+ if (JustReplace)
+ // Just replace this cast with the result.
+ return ReplaceInstUsesWith(CI, Res);
+
assert(Res->getType() == DestTy);
switch (CI.getOpcode()) {
default: assert(0 && "Unknown cast type!");
// Just replace this cast with the result.
return ReplaceInstUsesWith(CI, Res);
case Instruction::ZExt: {
- // We need to emit an AND to clear the high bits.
assert(SrcBitSize < DestBitSize && "Not a zext?");
+
+ // If the high bits are already zero, just replace this cast with the
+ // result.
+ APInt Mask(APInt::getBitsSet(DestBitSize, SrcBitSize, DestBitSize));
+ if (MaskedValueIsZero(Res, Mask))
+ return ReplaceInstUsesWith(CI, Res);
+
+ // We need to emit an AND to clear the high bits.
Constant *C = ConstantInt::get(APInt::getLowBitsSet(DestBitSize,
SrcBitSize));
return BinaryOperator::CreateAnd(Res, C);
}
- case Instruction::SExt:
+ case Instruction::SExt: {
+ // If the high bits are already filled with sign bit, just replace this
+ // cast with the result.
+ unsigned NumSignBits = ComputeNumSignBits(Res);
+ if (NumSignBits > (DestBitSize - SrcBitSize))
+ return ReplaceInstUsesWith(CI, Res);
+
// We need to emit a cast to truncate, then a cast to sext.
return CastInst::Create(Instruction::SExt,
InsertCastBefore(Instruction::Trunc, Res, Src->getType(),
CI), DestTy);
}
+ }
}
}
Value *Src = CI.getOperand(0);
- // If this is a cast of a cast
- if (CastInst *CSrc = dyn_cast<CastInst>(Src)) { // A->B->C cast
- // If this is a TRUNC followed by a ZEXT then we are dealing with integral
- // types and if the sizes are just right we can convert this into a logical
- // 'and' which will be much cheaper than the pair of casts.
- if (isa<TruncInst>(CSrc)) {
- // Get the sizes of the types involved
- Value *A = CSrc->getOperand(0);
- uint32_t SrcSize = A->getType()->getPrimitiveSizeInBits();
- uint32_t MidSize = CSrc->getType()->getPrimitiveSizeInBits();
- uint32_t DstSize = CI.getType()->getPrimitiveSizeInBits();
- // If we're actually extending zero bits and the trunc is a no-op
- if (MidSize < DstSize && SrcSize == DstSize) {
- // Replace both of the casts with an And of the type mask.
- APInt AndValue(APInt::getLowBitsSet(SrcSize, MidSize));
- Constant *AndConst = ConstantInt::get(AndValue);
- Instruction *And =
- BinaryOperator::CreateAnd(CSrc->getOperand(0), AndConst);
- // Unfortunately, if the type changed, we need to cast it back.
- if (And->getType() != CI.getType()) {
- And->setName(CSrc->getName()+".mask");
- InsertNewInstBefore(And, CI);
- And = CastInst::CreateIntegerCast(And, CI.getType(), false/*ZExt*/);
- }
- return And;
- }
+ // If this is a TRUNC followed by a ZEXT then we are dealing with integral
+ // types and if the sizes are just right we can convert this into a logical
+ // 'and' which will be much cheaper than the pair of casts.
+ if (TruncInst *CSrc = dyn_cast<TruncInst>(Src)) { // A->B->C cast
+ // Get the sizes of the types involved. We know that the intermediate type
+ // will be smaller than A or C, but don't know the relation between A and C.
+ Value *A = CSrc->getOperand(0);
+ unsigned SrcSize = A->getType()->getPrimitiveSizeInBits();
+ unsigned MidSize = CSrc->getType()->getPrimitiveSizeInBits();
+ unsigned DstSize = CI.getType()->getPrimitiveSizeInBits();
+ // If we're actually extending zero bits, then if
+ // SrcSize < DstSize: zext(a & mask)
+ // SrcSize == DstSize: a & mask
+ // SrcSize > DstSize: trunc(a) & mask
+ if (SrcSize < DstSize) {
+ APInt AndValue(APInt::getLowBitsSet(SrcSize, MidSize));
+ Constant *AndConst = ConstantInt::get(AndValue);
+ Instruction *And =
+ BinaryOperator::CreateAnd(A, AndConst, CSrc->getName()+".mask");
+ InsertNewInstBefore(And, CI);
+ return new ZExtInst(And, CI.getType());
+ } else if (SrcSize == DstSize) {
+ APInt AndValue(APInt::getLowBitsSet(SrcSize, MidSize));
+ return BinaryOperator::CreateAnd(A, ConstantInt::get(AndValue));
+ } else if (SrcSize > DstSize) {
+ Instruction *Trunc = new TruncInst(A, CI.getType(), "tmp");
+ InsertNewInstBefore(Trunc, CI);
+ APInt AndValue(APInt::getLowBitsSet(DstSize, MidSize));
+ return BinaryOperator::CreateAnd(Trunc, ConstantInt::get(AndValue));
}
}
// is a single-index GEP.
if (X->getType() == CI.getType()) {
// Get the size of the pointee type.
- uint64_t Size = TD->getABITypeSize(DestPointee);
+ uint64_t Size = TD->getTypePaddedSize(DestPointee);
// Convert the constant to intptr type.
APInt Offset = Cst->getValue();
// "inttoptr+GEP" instead of "add+intptr".
// Get the size of the pointee type.
- uint64_t Size = TD->getABITypeSize(DestPointee);
+ uint64_t Size = TD->getTypePaddedSize(DestPointee);
// Convert the constant to intptr type.
APInt Offset = Cst->getValue();
// (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
CmpInst::Predicate Pred = CmpInst::BAD_ICMP_PREDICATE;
- if (match(TrueVal, m_ConstantInt(-1)) &&
- match(FalseVal, m_ConstantInt(0)))
+ if (match(TrueVal, m_ConstantInt<-1>()) &&
+ match(FalseVal, m_ConstantInt<0>()))
Pred = ICI->getPredicate();
- else if (match(TrueVal, m_ConstantInt(0)) &&
- match(FalseVal, m_ConstantInt(-1)))
+ else if (match(TrueVal, m_ConstantInt<0>()) &&
+ match(FalseVal, m_ConstantInt<-1>()))
Pred = CmpInst::getInversePredicate(ICI->getPredicate());
if (Pred != CmpInst::BAD_ICMP_PREDICATE) {
// If there is a large requested alignment and we can, bump up the alignment
// of the global.
if (!GV->isDeclaration()) {
- GV->setAlignment(PrefAlign);
- Align = PrefAlign;
+ if (GV->getAlignment() >= PrefAlign)
+ Align = GV->getAlignment();
+ else {
+ GV->setAlignment(PrefAlign);
+ Align = PrefAlign;
+ }
}
} else if (AllocationInst *AI = dyn_cast<AllocationInst>(V)) {
// If there is a requested alignment and if this is an alloca, round up. We
// don't do this for malloc, because some systems can't respect the request.
if (isa<AllocaInst>(AI)) {
- AI->setAlignment(PrefAlign);
- Align = PrefAlign;
+ if (AI->getAlignment() >= PrefAlign)
+ Align = AI->getAlignment();
+ else {
+ AI->setAlignment(PrefAlign);
+ Align = PrefAlign;
+ }
}
}
case Intrinsic::x86_sse_cvttss2si: {
// These intrinsics only demands the 0th element of its input vector. If
// we can simplify the input based on that, do so now.
- uint64_t UndefElts;
- if (Value *V = SimplifyDemandedVectorElts(II->getOperand(1), 1,
+ unsigned VWidth =
+ cast<VectorType>(II->getOperand(1)->getType())->getNumElements();
+ APInt DemandedElts(VWidth, 1);
+ APInt UndefElts(VWidth, 0);
+ if (Value *V = SimplifyDemandedVectorElts(II->getOperand(1), DemandedElts,
UndefElts)) {
II->setOperand(1, V);
return II;
const Type* DstTy = cast<PointerType>(CI->getType())->getElementType();
if (!SrcTy->isSized() || !DstTy->isSized())
return false;
- if (TD->getABITypeSize(SrcTy) != TD->getABITypeSize(DstTy))
+ if (TD->getTypePaddedSize(SrcTy) != TD->getTypePaddedSize(DstTy))
return false;
return true;
}
SmallVector<Value*, 16> FixedOperands(FirstInst->op_begin(),
FirstInst->op_end());
+ // This is true if all GEP bases are allocas and if all indices into them are
+ // constants.
+ bool AllBasePointersAreAllocas = true;
// Scan to see if all operands are the same opcode, all have one use, and all
// kill their operands (i.e. the operands have one use).
GEP->getNumOperands() != FirstInst->getNumOperands())
return 0;
+ // Keep track of whether or not all GEPs are of alloca pointers.
+ if (AllBasePointersAreAllocas &&
+ (!isa<AllocaInst>(GEP->getOperand(0)) ||
+ !GEP->hasAllConstantIndices()))
+ AllBasePointersAreAllocas = false;
+
// Compare the operand lists.
for (unsigned op = 0, e = FirstInst->getNumOperands(); op != e; ++op) {
if (FirstInst->getOperand(op) == GEP->getOperand(op))
}
}
+ // If all of the base pointers of the PHI'd GEPs are from allocas, don't
+ // bother doing this transformation. At best, this will just save a bit of
+ // offset calculation, but all the predecessors will have to materialize the
+ // stack address into a register anyway. We'd actually rather *clone* the
+ // load up into the predecessors so that we have a load of a gep of an alloca,
+ // which can usually all be folded into the load.
+ if (AllBasePointersAreAllocas)
+ return 0;
+
// Otherwise, this is safe to transform. Insert PHI nodes for each operand
// that is variable.
SmallVector<PHINode*, 16> OperandPhis(FixedOperands.size());
}
-/// isSafeToSinkLoad - Return true if we know that it is safe sink the load out
-/// of the block that defines it. This means that it must be obvious the value
-/// of the load is not changed from the point of the load to the end of the
-/// block it is in.
+/// isSafeAndProfitableToSinkLoad - Return true if we know that it is safe to
+/// sink the load out of the block that defines it. This means that it must be
+/// obvious the value of the load is not changed from the point of the load to
+/// the end of the block it is in.
///
/// Finally, it is safe, but not profitable, to sink a load targetting a
/// non-address-taken alloca. Doing so will cause us to not promote the alloca
/// to a register.
-static bool isSafeToSinkLoad(LoadInst *L) {
+static bool isSafeAndProfitableToSinkLoad(LoadInst *L) {
BasicBlock::iterator BBI = L, E = L->getParent()->end();
for (++BBI; BBI != E; ++BBI)
break;
}
- if (!isAddressTaken)
+ if (!isAddressTaken && AI->isStaticAlloca())
return false;
}
+ // If this load is a load from a GEP with a constant offset from an alloca,
+ // then we don't want to sink it. In its present form, it will be
+ // load [constant stack offset]. Sinking it will cause us to have to
+ // materialize the stack addresses in each predecessor in a register only to
+ // do a shared load from register in the successor.
+ if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(L->getOperand(0)))
+ if (AllocaInst *AI = dyn_cast<AllocaInst>(GEP->getOperand(0)))
+ if (AI->isStaticAlloca() && GEP->hasAllConstantIndices())
+ return false;
+
return true;
}
// We can't sink the load if the loaded value could be modified between the
// load and the PHI.
if (LI->getParent() != PN.getIncomingBlock(0) ||
- !isSafeToSinkLoad(LI))
+ !isSafeAndProfitableToSinkLoad(LI))
return 0;
// If the PHI is of volatile loads and the load block has multiple
// the load and the PHI.
if (LI->isVolatile() != isVolatile ||
LI->getParent() != PN.getIncomingBlock(i) ||
- !isSafeToSinkLoad(LI))
+ !isSafeAndProfitableToSinkLoad(LI))
return 0;
// If the PHI is of volatile loads and the load block has multiple
if (isVolatile &&
LI->getParent()->getTerminator()->getNumSuccessors() != 1)
return 0;
-
} else if (I->getOperand(1) != ConstantOp) {
return 0;
}
if (MadeChange) return &GEP;
- // If this GEP instruction doesn't move the pointer, and if the input operand
- // is a bitcast of another pointer, just replace the GEP with a bitcast of the
- // real input to the dest type.
- if (GEP.hasAllZeroIndices()) {
- if (BitCastInst *BCI = dyn_cast<BitCastInst>(GEP.getOperand(0))) {
- // If the bitcast is of an allocation, and the allocation will be
- // converted to match the type of the cast, don't touch this.
- if (isa<AllocationInst>(BCI->getOperand(0))) {
- // See if the bitcast simplifies, if so, don't nuke this GEP yet.
- if (Instruction *I = visitBitCast(*BCI)) {
- if (I != BCI) {
- I->takeName(BCI);
- BCI->getParent()->getInstList().insert(BCI, I);
- ReplaceInstUsesWith(*BCI, I);
- }
- return &GEP;
- }
- }
- return new BitCastInst(BCI->getOperand(0), GEP.getType());
- }
- }
-
// Combine Indices - If the source pointer to this getelementptr instruction
// is a getelementptr instruction, combine the indices of the two
// getelementptr instructions into a single instruction.
// transform: GEP (bitcast [10 x i8]* X to [0 x i8]*), i32 0, ...
// into : GEP [10 x i8]* X, i32 0, ...
//
+ // Likewise, transform: GEP (bitcast i8* X to [0 x i8]*), i32 0, ...
+ // into : GEP i8* X, ...
+ //
// This occurs when the program declares an array extern like "int X[];"
- //
const PointerType *CPTy = cast<PointerType>(PtrOp->getType());
const PointerType *XTy = cast<PointerType>(X->getType());
- if (const ArrayType *XATy =
- dyn_cast<ArrayType>(XTy->getElementType()))
- if (const ArrayType *CATy =
- dyn_cast<ArrayType>(CPTy->getElementType()))
+ if (const ArrayType *CATy =
+ dyn_cast<ArrayType>(CPTy->getElementType())) {
+ // GEP (bitcast i8* X to [0 x i8]*), i32 0, ... ?
+ if (CATy->getElementType() == XTy->getElementType()) {
+ // -> GEP i8* X, ...
+ SmallVector<Value*, 8> Indices(GEP.idx_begin()+1, GEP.idx_end());
+ return GetElementPtrInst::Create(X, Indices.begin(), Indices.end(),
+ GEP.getName());
+ } else if (const ArrayType *XATy =
+ dyn_cast<ArrayType>(XTy->getElementType())) {
+ // GEP (bitcast [10 x i8]* X to [0 x i8]*), i32 0, ... ?
if (CATy->getElementType() == XATy->getElementType()) {
+ // -> GEP [10 x i8]* X, i32 0, ...
// At this point, we know that the cast source type is a pointer
// to an array of the same type as the destination pointer
// array. Because the array type is never stepped over (there
GEP.setOperand(0, X);
return &GEP;
}
+ }
+ }
} else if (GEP.getNumOperands() == 2) {
// Transform things like:
// %t = getelementptr i32* bitcast ([2 x i32]* %str to i32*), i32 %V
const Type *SrcElTy = cast<PointerType>(X->getType())->getElementType();
const Type *ResElTy=cast<PointerType>(PtrOp->getType())->getElementType();
if (isa<ArrayType>(SrcElTy) &&
- TD->get
ABITypeSize(cast<ArrayType>(SrcElTy)->getElementType()) ==
- TD->getABITypeSize(ResElTy)) {
+ TD->get
TypePaddedSize(cast<ArrayType>(SrcElTy)->getElementType()) ==
+ TD->getTypePaddedSize(ResElTy)) {
Value *Idx[2];
Idx[0] = Constant::getNullValue(Type::Int32Ty);
Idx[1] = GEP.getOperand(1);
if (isa<ArrayType>(SrcElTy) && ResElTy == Type::Int8Ty) {
uint64_t ArrayEltSize =
- TD->get
ABITypeSize(cast<ArrayType>(SrcElTy)->getElementType());
+ TD->get
TypePaddedSize(cast<ArrayType>(SrcElTy)->getElementType());
// Check to see if "tmp" is a scale by a multiple of ArrayEltSize. We
// allow either a mul, shift, or constant here.
// out, perform the transformation. Note, we don't know whether Scale is
// signed or not. We'll use unsigned version of division/modulo
// operation after making sure Scale doesn't have the sign bit set.
- if (Scale && Scale->getSExtValue() >= 0LL &&
+ if (ArrayEltSize && Scale && Scale->getSExtValue() >= 0LL &&
Scale->getZExtValue() % ArrayEltSize == 0) {
Scale = ConstantInt::get(Scale->getType(),
Scale->getZExtValue() / ArrayEltSize);
}
}
}
-
+
+ /// See if we can simplify:
+ /// X = bitcast A to B*
+ /// Y = gep X, <...constant indices...>
+ /// into a gep of the original struct. This is important for SROA and alias
+ /// analysis of unions. If "A" is also a bitcast, wait for A/X to be merged.
+ if (BitCastInst *BCI = dyn_cast<BitCastInst>(PtrOp)) {
+ if (!isa<BitCastInst>(BCI->getOperand(0)) && GEP.hasAllConstantIndices()) {
+ // Determine how much the GEP moves the pointer. We are guaranteed to get
+ // a constant back from EmitGEPOffset.
+ ConstantInt *OffsetV = cast<ConstantInt>(EmitGEPOffset(&GEP, GEP, *this));
+ int64_t Offset = OffsetV->getSExtValue();
+
+ // If this GEP instruction doesn't move the pointer, just replace the GEP
+ // with a bitcast of the real input to the dest type.
+ if (Offset == 0) {
+ // If the bitcast is of an allocation, and the allocation will be
+ // converted to match the type of the cast, don't touch this.
+ if (isa<AllocationInst>(BCI->getOperand(0))) {
+ // See if the bitcast simplifies, if so, don't nuke this GEP yet.
+ if (Instruction *I = visitBitCast(*BCI)) {
+ if (I != BCI) {
+ I->takeName(BCI);
+ BCI->getParent()->getInstList().insert(BCI, I);
+ ReplaceInstUsesWith(*BCI, I);
+ }
+ return &GEP;
+ }
+ }
+ return new BitCastInst(BCI->getOperand(0), GEP.getType());
+ }
+
+ // Otherwise, if the offset is non-zero, we need to find out if there is a
+ // field at Offset in 'A's type. If so, we can pull the cast through the
+ // GEP.
+ SmallVector<Value*, 8> NewIndices;
+ const Type *InTy =
+ cast<PointerType>(BCI->getOperand(0)->getType())->getElementType();
+ if (FindElementAtOffset(InTy, Offset, NewIndices, TD)) {
+ Instruction *NGEP =
+ GetElementPtrInst::Create(BCI->getOperand(0), NewIndices.begin(),
+ NewIndices.end());
+ if (NGEP->getType() == GEP.getType()) return NGEP;
+ InsertNewInstBefore(NGEP, GEP);
+ NGEP->takeName(&GEP);
+ return new BitCastInst(NGEP, GEP.getType());
+ }
+ }
+ }
+
return 0;
}
}
}
- // If alloca'ing a zero byte object, replace the alloca with a null pointer.
- // Note that we only do this for alloca's, because malloc should allocate and
- // return a unique pointer, even for a zero byte allocation.
- if (isa<AllocaInst>(AI) && AI.getAllocatedType()->isSized() &&
- TD->getABITypeSize(AI.getAllocatedType()) == 0)
- return ReplaceInstUsesWith(AI, Constant::getNullValue(AI.getType()));
+ if (isa<AllocaInst>(AI) && AI.getAllocatedType()->isSized()) {
+ // If alloca'ing a zero byte object, replace the alloca with a null pointer.
+ // Note that we only do this for alloca's, because malloc should allocate and
+ // return a unique pointer, even for a zero byte allocation.
+ if (TD->getTypePaddedSize(AI.getAllocatedType()) == 0)
+ return ReplaceInstUsesWith(AI, Constant::getNullValue(AI.getType()));
+
+ // If the alignment is 0 (unspecified), assign it the preferred alignment.
+ if (AI.getAlignment() == 0)
+ AI.setAlignment(TD->getPrefTypeAlignment(AI.getAllocatedType()));
+ }
return 0;
}
APInt SingleChar(numBits, 0);
if (TD->isLittleEndian()) {
for (signed i = len-1; i >= 0; i--) {
- SingleChar = (uint64_t) Str[i];
+ SingleChar = (uint64_t) Str[i] & UCHAR_MAX;
StrVal = (StrVal << 8) | SingleChar;
}
} else {
for (unsigned i = 0; i < len; i++) {
- SingleChar = (uint64_t) Str[i];
+ SingleChar = (uint64_t) Str[i] & UCHAR_MAX;
StrVal = (StrVal << 8) | SingleChar;
}
// Append NULL at the end.
}
}
- const Type *DestPTy = cast<PointerType>(CI->getType())->getElementType();
+ const PointerType *DestTy = cast<PointerType>(CI->getType());
+ const Type *DestPTy = DestTy->getElementType();
if (const PointerType *SrcTy = dyn_cast<PointerType>(CastOp->getType())) {
+
+ // If the address spaces don't match, don't eliminate the cast.
+ if (DestTy->getAddressSpace() != SrcTy->getAddressSpace())
+ return 0;
+
const Type *SrcPTy = SrcTy->getElementType();
if (DestPTy->isInteger() || isa<PointerType>(DestPTy) ||
Value *Op = LI.getOperand(0);
// Attempt to improve the alignment.
- unsigned KnownAlign = GetOrEnforceKnownAlignment(Op);
+ unsigned KnownAlign =
+ GetOrEnforceKnownAlignment(Op, TD->getPrefTypeAlignment(LI.getType()));
if (KnownAlign >
(LI.getAlignment() == 0 ? TD->getABITypeAlignment(LI.getType()) :
LI.getAlignment()))
}
/// InstCombineStoreToCast - Fold store V, (cast P) -> store (cast V), P
-/// when possible.
+/// when possible. This makes it generally easy to do alias analysis and/or
+/// SROA/mem2reg of the memory object.
static Instruction *InstCombineStoreToCast(InstCombiner &IC, StoreInst &SI) {
User *CI = cast<User>(SI.getOperand(1));
Value *CastOp = CI->getOperand(0);
const Type *DestPTy = cast<PointerType>(CI->getType())->getElementType();
- if (const PointerType *SrcTy = dyn_cast<PointerType>(CastOp->getType())) {
- const Type *SrcPTy = SrcTy->getElementType();
-
- if (DestPTy->isInteger() || isa<PointerType>(DestPTy)) {
- // If the source is an array, the code below will not succeed. Check to
- // see if a trivial 'gep P, 0, 0' will help matters. Only do this for
- // constants.
- if (const ArrayType *ASrcTy = dyn_cast<ArrayType>(SrcPTy))
- if (Constant *CSrc = dyn_cast<Constant>(CastOp))
- if (ASrcTy->getNumElements() != 0) {
- Value* Idxs[2];
- Idxs[0] = Idxs[1] = Constant::getNullValue(Type::Int32Ty);
- CastOp = ConstantExpr::getGetElementPtr(CSrc, Idxs, 2);
- SrcTy = cast<PointerType>(CastOp->getType());
- SrcPTy = SrcTy->getElementType();
- }
-
- if ((SrcPTy->isInteger() || isa<PointerType>(SrcPTy)) &&
- IC.getTargetData().getTypeSizeInBits(SrcPTy) ==
- IC.getTargetData().getTypeSizeInBits(DestPTy)) {
+ const PointerType *SrcTy = dyn_cast<PointerType>(CastOp->getType());
+ if (SrcTy == 0) return 0;
+
+ const Type *SrcPTy = SrcTy->getElementType();
- // Okay, we are casting from one integer or pointer type to another of
- // the same size. Instead of casting the pointer before
- // the store, cast the value to be stored.
- Value *NewCast;
- Value *SIOp0 = SI.getOperand(0);
- Instruction::CastOps opcode = Instruction::BitCast;
- const Type* CastSrcTy = SIOp0->getType();
- const Type* CastDstTy = SrcPTy;
- if (isa<PointerType>(CastDstTy)) {
- if (CastSrcTy->isInteger())
- opcode = Instruction::IntToPtr;
- } else if (isa<IntegerType>(CastDstTy)) {
- if (isa<PointerType>(SIOp0->getType()))
- opcode = Instruction::PtrToInt;
- }
- if (Constant *C = dyn_cast<Constant>(SIOp0))
- NewCast = ConstantExpr::getCast(opcode, C, CastDstTy);
- else
- NewCast = IC.InsertNewInstBefore(
- CastInst::Create(opcode, SIOp0, CastDstTy, SIOp0->getName()+".c"),
- SI);
- return new StoreInst(NewCast, CastOp);
+ if (!DestPTy->isInteger() && !isa<PointerType>(DestPTy))
+ return 0;
+
+ /// NewGEPIndices - If SrcPTy is an aggregate type, we can emit a "noop gep"
+ /// to its first element. This allows us to handle things like:
+ /// store i32 xxx, (bitcast {foo*, float}* %P to i32*)
+ /// on 32-bit hosts.
+ SmallVector<Value*, 4> NewGEPIndices;
+
+ // If the source is an array, the code below will not succeed. Check to
+ // see if a trivial 'gep P, 0, 0' will help matters. Only do this for
+ // constants.
+ if (isa<ArrayType>(SrcPTy) || isa<StructType>(SrcPTy)) {
+ // Index through pointer.
+ Constant *Zero = Constant::getNullValue(Type::Int32Ty);
+ NewGEPIndices.push_back(Zero);
+
+ while (1) {
+ if (const StructType *STy = dyn_cast<StructType>(SrcPTy)) {
+ if (!STy->getNumElements()) /* Struct can be empty {} */
+ break;
+ NewGEPIndices.push_back(Zero);
+ SrcPTy = STy->getElementType(0);
+ } else if (const ArrayType *ATy = dyn_cast<ArrayType>(SrcPTy)) {
+ NewGEPIndices.push_back(Zero);
+ SrcPTy = ATy->getElementType();
+ } else {
+ break;
}
}
+
+ SrcTy = PointerType::get(SrcPTy, SrcTy->getAddressSpace());
}
- return 0;
+
+ if (!SrcPTy->isInteger() && !isa<PointerType>(SrcPTy))
+ return 0;
+
+ // If the pointers point into different address spaces or if they point to
+ // values with different sizes, we can't do the transformation.
+ if (SrcTy->getAddressSpace() !=
+ cast<PointerType>(CI->getType())->getAddressSpace() ||
+ IC.getTargetData().getTypeSizeInBits(SrcPTy) !=
+ IC.getTargetData().getTypeSizeInBits(DestPTy))
+ return 0;
+
+ // Okay, we are casting from one integer or pointer type to another of
+ // the same size. Instead of casting the pointer before
+ // the store, cast the value to be stored.
+ Value *NewCast;
+ Value *SIOp0 = SI.getOperand(0);
+ Instruction::CastOps opcode = Instruction::BitCast;
+ const Type* CastSrcTy = SIOp0->getType();
+ const Type* CastDstTy = SrcPTy;
+ if (isa<PointerType>(CastDstTy)) {
+ if (CastSrcTy->isInteger())
+ opcode = Instruction::IntToPtr;
+ } else if (isa<IntegerType>(CastDstTy)) {
+ if (isa<PointerType>(SIOp0->getType()))
+ opcode = Instruction::PtrToInt;
+ }
+
+ // SIOp0 is a pointer to aggregate and this is a store to the first field,
+ // emit a GEP to index into its first field.
+ if (!NewGEPIndices.empty()) {
+ if (Constant *C = dyn_cast<Constant>(CastOp))
+ CastOp = ConstantExpr::getGetElementPtr(C, &NewGEPIndices[0],
+ NewGEPIndices.size());
+ else
+ CastOp = IC.InsertNewInstBefore(
+ GetElementPtrInst::Create(CastOp, NewGEPIndices.begin(),
+ NewGEPIndices.end()), SI);
+ }
+
+ if (Constant *C = dyn_cast<Constant>(SIOp0))
+ NewCast = ConstantExpr::getCast(opcode, C, CastDstTy);
+ else
+ NewCast = IC.InsertNewInstBefore(
+ CastInst::Create(opcode, SIOp0, CastDstTy, SIOp0->getName()+".c"),
+ SI);
+ return new StoreInst(NewCast, CastOp);
}
/// equivalentAddressValues - Test if A and B will obviously have the same
}
// Attempt to improve the alignment.
- unsigned KnownAlign = GetOrEnforceKnownAlignment(Ptr);
+ unsigned KnownAlign =
+ GetOrEnforceKnownAlignment(Ptr, TD->getPrefTypeAlignment(Val->getType()));
if (KnownAlign >
(SI.getAlignment() == 0 ? TD->getABITypeAlignment(Val->getType()) :
SI.getAlignment()))
// If the input vector has a single use, simplify it based on this use
// property.
if (EI.getOperand(0)->hasOneUse() && VectorWidth != 1) {
- uint64_t UndefElts;
+ APInt UndefElts(VectorWidth, 0);
+ APInt DemandedMask(VectorWidth, 1 << IndexVal);
if (Value *V = SimplifyDemandedVectorElts(EI.getOperand(0),
- 1 << IndexVal,
- UndefElts)) {
+ DemandedMask, UndefElts)) {
EI.setOperand(0, V);
return &EI;
}
if (isa<UndefValue>(SVI.getOperand(2)))
return ReplaceInstUsesWith(SVI, UndefValue::get(SVI.getType()));
- uint64_t UndefElts;
unsigned VWidth = cast<VectorType>(SVI.getType())->getNumElements();
if (VWidth != cast<VectorType>(LHS->getType())->getNumElements())
return 0;
- uint64_t AllOnesEltMask = ~0ULL >> (64-VWidth);
- if (VWidth <= 64 &&
- SimplifyDemandedVectorElts(&SVI, AllOnesEltMask, UndefElts)) {
+ APInt UndefElts(VWidth, 0);
+ APInt AllOnesEltMask(APInt::getAllOnesValue(VWidth));
+ if (SimplifyDemandedVectorElts(&SVI, AllOnesEltMask, UndefElts)) {
LHS = SVI.getOperand(0);
RHS = SVI.getOperand(1);
MadeChange = true;
// If the result mask is equal to the src shuffle or this shuffle mask, do
// the replacement.
if (NewMask == LHSMask || NewMask == Mask) {
+ unsigned LHSInNElts =
+ cast<VectorType>(LHSSVI->getOperand(0)->getType())->getNumElements();
std::vector<Constant*> Elts;
for (unsigned i = 0, e = NewMask.size(); i != e; ++i) {
- if (NewMask[i] >= e*2) {
+ if (NewMask[i] >= LHSInNElts*2) {
Elts.push_back(UndefValue::get(Type::Int32Ty));
} else {
Elts.push_back(ConstantInt::get(Type::Int32Ty, NewMask[i]));
BasicBlock::iterator InsertPos = DestBlock->getFirstNonPHI();
+ CopyPrecedingStopPoint(I, InsertPos);
I->moveBefore(InsertPos);
++NumSunkInst;
return true;
DBI_Prev->eraseFromParent();
}
DBI_Prev = DBI_Next;
+ } else {
+ DBI_Prev = 0;
}
IC.AddToWorkList(Inst);
if (!I->use_empty())
I->replaceAllUsesWith(UndefValue::get(I->getType()));
I->eraseFromParent();
+ Changed = true;
}
}
}
I->eraseFromParent();
RemoveFromWorkList(I);
+ Changed = true;
continue;
}
++NumConstProp;
I->eraseFromParent();
RemoveFromWorkList(I);
+ Changed = true;
continue;
}
if (TD && I->getType()->getTypeID() == Type::VoidTyID) {
// See if we can constant fold its operands.
- for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) {
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(i)) {
+ for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i)
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(i))
if (Constant *NewC = ConstantFoldConstantExpression(CE, TD))
- i->set(NewC);
- }
- }
+ if (NewC != CE) {
+ i->set(NewC);
+ Changed = true;
+ }
}
// See if we can trivially sink this instruction to a successor basic block.
FunctionPass *llvm::createInstructionCombiningPass() {
return new InstCombiner();
}
-
-
projects / oota-llvm.git / blobdiff