#include "llvm/Target/TargetData.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Support/CallSite.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
}
-// getPromotedType - Return the specified type promoted as it would be to pass
-// though a va_arg area.
-static const Type *getPromotedType(const Type *Ty) {
- if (const IntegerType* ITy = dyn_cast<IntegerType>(Ty)) {
- if (ITy->getBitWidth() < 32)
- return Type::getInt32Ty(Ty->getContext());
- }
- return Ty;
-}
-
/// ShouldChangeType - Return true if it is desirable to convert a computation
/// from 'From' to 'To'. We don't want to convert from a legal to an illegal
/// type for example, or from a smaller to a larger illegal type.
return true;
}
-/// getBitCastOperand - If the specified operand is a CastInst, a constant
-/// expression bitcast, or a GetElementPtrInst with all zero indices, return the
-/// operand value, otherwise return null.
-static Value *getBitCastOperand(Value *V) {
- if (Operator *O = dyn_cast<Operator>(V)) {
- if (O->getOpcode() == Instruction::BitCast)
- return O->getOperand(0);
- if (GEPOperator *GEP = dyn_cast<GEPOperator>(V))
- if (GEP->hasAllZeroIndices())
- return GEP->getPointerOperand();
- }
- return 0;
-}
-
-
// SimplifyCommutative - This performs a few simplifications for commutative
// operators:
return 0;
}
-/// isFreeToInvert - Return true if the specified value is free to invert (apply
-/// ~ to). This happens in cases where the ~ can be eliminated.
-static inline bool isFreeToInvert(Value *V) {
- // ~(~(X)) -> X.
- if (BinaryOperator::isNot(V))
- return true;
-
- // Constants can be considered to be not'ed values.
- if (isa<ConstantInt>(V))
- return true;
-
- // Compares can be inverted if they have a single use.
- if (CmpInst *CI = dyn_cast<CmpInst>(V))
- return CI->hasOneUse();
-
- return false;
-}
-
-static inline Value *dyn_castNotVal(Value *V) {
- // If this is not(not(x)) don't return that this is a not: we want the two
- // not's to be folded first.
- if (BinaryOperator::isNot(V)) {
- Value *Operand = BinaryOperator::getNotArgument(V);
- if (!isFreeToInvert(Operand))
- return Operand;
- }
-
- // Constants can be considered to be not'ed values...
- if (ConstantInt *C = dyn_cast<ConstantInt>(V))
- return ConstantInt::get(C->getType(), ~C->getValue());
- return 0;
-}
-
-
-
-// dyn_castFoldableMul - If this value is a multiply that can be folded into
-// other computations (because it has a constant operand), return the
-// non-constant operand of the multiply, and set CST to point to the multiplier.
-// Otherwise, return null.
-//
-static inline Value *dyn_castFoldableMul(Value *V, ConstantInt *&CST) {
- if (V->hasOneUse() && V->getType()->isInteger())
- if (Instruction *I = dyn_cast<Instruction>(V)) {
- if (I->getOpcode() == Instruction::Mul)
- if ((CST = dyn_cast<ConstantInt>(I->getOperand(1))))
- return I->getOperand(0);
- if (I->getOpcode() == Instruction::Shl)
- if ((CST = dyn_cast<ConstantInt>(I->getOperand(1)))) {
- // The multiplier is really 1 << CST.
- uint32_t BitWidth = cast<IntegerType>(V->getType())->getBitWidth();
- uint32_t CSTVal = CST->getLimitedValue(BitWidth);
- CST = ConstantInt::get(V->getType()->getContext(),
- APInt(BitWidth, 1).shl(CSTVal));
- return I->getOperand(0);
- }
- }
- return 0;
-}
-
-/// AddOne - Add one to a ConstantInt.
-static Constant *AddOne(Constant *C) {
- return ConstantExpr::getAdd(C, ConstantInt::get(C->getType(), 1));
-}
-/// SubOne - Subtract one from a ConstantInt.
-static Constant *SubOne(ConstantInt *C) {
- return ConstantInt::get(C->getContext(), C->getValue()-1);
-}
-
-
static Value *FoldOperationIntoSelectOperand(Instruction &I, Value *SO,
InstCombiner *IC) {
if (CastInst *CI = dyn_cast<CastInst>(&I))
return ReplaceInstUsesWith(I, NewPN);
}
-
-/// getICmpCode - Encode a icmp predicate into a three bit mask. These bits
-/// are carefully arranged to allow folding of expressions such as:
-///
-/// (A < B) | (A > B) --> (A != B)
-///
-/// Note that this is only valid if the first and second predicates have the
-/// same sign. Is illegal to do: (A u< B) | (A s> B)
-///
-/// Three bits are used to represent the condition, as follows:
-/// 0 A > B
-/// 1 A == B
-/// 2 A < B
-///
-/// <=> Value Definition
-/// 000 0 Always false
-/// 001 1 A > B
-/// 010 2 A == B
-/// 011 3 A >= B
-/// 100 4 A < B
-/// 101 5 A != B
-/// 110 6 A <= B
-/// 111 7 Always true
-///
-static unsigned getICmpCode(const ICmpInst *ICI) {
- switch (ICI->getPredicate()) {
- // False -> 0
- case ICmpInst::ICMP_UGT: return 1; // 001
- case ICmpInst::ICMP_SGT: return 1; // 001
- case ICmpInst::ICMP_EQ: return 2; // 010
- case ICmpInst::ICMP_UGE: return 3; // 011
- case ICmpInst::ICMP_SGE: return 3; // 011
- case ICmpInst::ICMP_ULT: return 4; // 100
- case ICmpInst::ICMP_SLT: return 4; // 100
- case ICmpInst::ICMP_NE: return 5; // 101
- case ICmpInst::ICMP_ULE: return 6; // 110
- case ICmpInst::ICMP_SLE: return 6; // 110
- // True -> 7
- default:
- llvm_unreachable("Invalid ICmp predicate!");
- return 0;
- }
-}
-
-/// getFCmpCode - Similar to getICmpCode but for FCmpInst. This encodes a fcmp
-/// predicate into a three bit mask. It also returns whether it is an ordered
-/// predicate by reference.
-static unsigned getFCmpCode(FCmpInst::Predicate CC, bool &isOrdered) {
- isOrdered = false;
- switch (CC) {
- case FCmpInst::FCMP_ORD: isOrdered = true; return 0; // 000
- case FCmpInst::FCMP_UNO: return 0; // 000
- case FCmpInst::FCMP_OGT: isOrdered = true; return 1; // 001
- case FCmpInst::FCMP_UGT: return 1; // 001
- case FCmpInst::FCMP_OEQ: isOrdered = true; return 2; // 010
- case FCmpInst::FCMP_UEQ: return 2; // 010
- case FCmpInst::FCMP_OGE: isOrdered = true; return 3; // 011
- case FCmpInst::FCMP_UGE: return 3; // 011
- case FCmpInst::FCMP_OLT: isOrdered = true; return 4; // 100
- case FCmpInst::FCMP_ULT: return 4; // 100
- case FCmpInst::FCMP_ONE: isOrdered = true; return 5; // 101
- case FCmpInst::FCMP_UNE: return 5; // 101
- case FCmpInst::FCMP_OLE: isOrdered = true; return 6; // 110
- case FCmpInst::FCMP_ULE: return 6; // 110
- // True -> 7
- default:
- // Not expecting FCMP_FALSE and FCMP_TRUE;
- llvm_unreachable("Unexpected FCmp predicate!");
- return 0;
- }
-}
-
-/// getICmpValue - This is the complement of getICmpCode, which turns an
-/// opcode and two operands into either a constant true or false, or a brand
-/// new ICmp instruction. The sign is passed in to determine which kind
-/// of predicate to use in the new icmp instruction.
-static Value *getICmpValue(bool Sign, unsigned Code, Value *LHS, Value *RHS) {
- switch (Code) {
- default: assert(0 && "Illegal ICmp code!");
- case 0:
- return ConstantInt::getFalse(LHS->getContext());
- case 1:
- if (Sign)
- return new ICmpInst(ICmpInst::ICMP_SGT, LHS, RHS);
- return new ICmpInst(ICmpInst::ICMP_UGT, LHS, RHS);
- case 2:
- return new ICmpInst(ICmpInst::ICMP_EQ, LHS, RHS);
- case 3:
- if (Sign)
- return new ICmpInst(ICmpInst::ICMP_SGE, LHS, RHS);
- return new ICmpInst(ICmpInst::ICMP_UGE, LHS, RHS);
- case 4:
- if (Sign)
- return new ICmpInst(ICmpInst::ICMP_SLT, LHS, RHS);
- return new ICmpInst(ICmpInst::ICMP_ULT, LHS, RHS);
- case 5:
- return new ICmpInst(ICmpInst::ICMP_NE, LHS, RHS);
- case 6:
- if (Sign)
- return new ICmpInst(ICmpInst::ICMP_SLE, LHS, RHS);
- return new ICmpInst(ICmpInst::ICMP_ULE, LHS, RHS);
- case 7:
- return ConstantInt::getTrue(LHS->getContext());
+/// 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.
+const Type *InstCombiner::FindElementAtOffset(const Type *Ty, int64_t Offset,
+ SmallVectorImpl<Value*> &NewIndices) {
+ if (!TD) return 0;
+ 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(Ty->getContext());
+ int64_t FirstIdx = 0;
+ if (int64_t TySize = TD->getTypeAllocSize(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");
}
-}
-
-/// getFCmpValue - This is the complement of getFCmpCode, which turns an
-/// opcode and two operands into either a FCmp instruction. isordered is passed
-/// in to determine which kind of predicate to use in the new fcmp instruction.
-static Value *getFCmpValue(bool isordered, unsigned code,
- Value *LHS, Value *RHS) {
- switch (code) {
- default: llvm_unreachable("Illegal FCmp code!");
- case 0:
- if (isordered)
- return new FCmpInst(FCmpInst::FCMP_ORD, LHS, RHS);
- else
- return new FCmpInst(FCmpInst::FCMP_UNO, LHS, RHS);
- case 1:
- if (isordered)
- return new FCmpInst(FCmpInst::FCMP_OGT, LHS, RHS);
- else
- return new FCmpInst(FCmpInst::FCMP_UGT, LHS, RHS);
- case 2:
- if (isordered)
- return new FCmpInst(FCmpInst::FCMP_OEQ, LHS, RHS);
- else
- return new FCmpInst(FCmpInst::FCMP_UEQ, LHS, RHS);
- case 3:
- if (isordered)
- return new FCmpInst(FCmpInst::FCMP_OGE, LHS, RHS);
- else
- return new FCmpInst(FCmpInst::FCMP_UGE, LHS, RHS);
- case 4:
- if (isordered)
- return new FCmpInst(FCmpInst::FCMP_OLT, LHS, RHS);
- else
- return new FCmpInst(FCmpInst::FCMP_ULT, LHS, RHS);
- case 5:
- if (isordered)
- return new FCmpInst(FCmpInst::FCMP_ONE, LHS, RHS);
- else
- return new FCmpInst(FCmpInst::FCMP_UNE, LHS, RHS);
- case 6:
- if (isordered)
- return new FCmpInst(FCmpInst::FCMP_OLE, LHS, RHS);
- else
- return new FCmpInst(FCmpInst::FCMP_ULE, LHS, RHS);
- case 7: return ConstantInt::getTrue(LHS->getContext());
+
+ 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::getInt32Ty(Ty->getContext()),
+ Elt));
+
+ Offset -= SL->getElementOffset(Elt);
+ Ty = STy->getElementType(Elt);
+ } else if (const ArrayType *AT = dyn_cast<ArrayType>(Ty)) {
+ uint64_t EltSize = TD->getTypeAllocSize(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;
}
-/// PredicatesFoldable - Return true if both predicates match sign or if at
-/// least one of them is an equality comparison (which is signless).
-static bool PredicatesFoldable(ICmpInst::Predicate p1, ICmpInst::Predicate p2) {
- return (CmpInst::isSigned(p1) == CmpInst::isSigned(p2)) ||
- (CmpInst::isSigned(p1) && ICmpInst::isEquality(p2)) ||
- (CmpInst::isSigned(p2) && ICmpInst::isEquality(p1));
-}
-
-// OptAndOp - This handles expressions of the form ((val OP C1) & C2). Where
-// the Op parameter is 'OP', OpRHS is 'C1', and AndRHS is 'C2'. Op is
-// guaranteed to be a binary operator.
-Instruction *InstCombiner::OptAndOp(Instruction *Op,
- ConstantInt *OpRHS,
- ConstantInt *AndRHS,
- BinaryOperator &TheAnd) {
- Value *X = Op->getOperand(0);
- Constant *Together = 0;
- if (!Op->isShift())
- Together = ConstantExpr::getAnd(AndRHS, OpRHS);
-
- switch (Op->getOpcode()) {
- case Instruction::Xor:
- if (Op->hasOneUse()) {
- // (X ^ C1) & C2 --> (X & C2) ^ (C1&C2)
- Value *And = Builder->CreateAnd(X, AndRHS);
- And->takeName(Op);
- return BinaryOperator::CreateXor(And, Together);
- }
- break;
- case Instruction::Or:
- if (Together == AndRHS) // (X | C) & C --> C
- return ReplaceInstUsesWith(TheAnd, AndRHS);
-
- if (Op->hasOneUse() && Together != OpRHS) {
- // (X | C1) & C2 --> (X | (C1&C2)) & C2
- Value *Or = Builder->CreateOr(X, Together);
- Or->takeName(Op);
- return BinaryOperator::CreateAnd(Or, AndRHS);
- }
- break;
- case Instruction::Add:
- if (Op->hasOneUse()) {
- // Adding a one to a single bit bit-field should be turned into an XOR
- // of the bit. First thing to check is to see if this AND is with a
- // single bit constant.
- const APInt &AndRHSV = cast<ConstantInt>(AndRHS)->getValue();
-
- // If there is only one bit set.
- if (AndRHSV.isPowerOf2()) {
- // Ok, at this point, we know that we are masking the result of the
- // ADD down to exactly one bit. If the constant we are adding has
- // no bits set below this bit, then we can eliminate the ADD.
- const APInt& AddRHS = cast<ConstantInt>(OpRHS)->getValue();
- // Check to see if any bits below the one bit set in AndRHSV are set.
- if ((AddRHS & (AndRHSV-1)) == 0) {
- // If not, the only thing that can effect the output of the AND is
- // the bit specified by AndRHSV. If that bit is set, the effect of
- // the XOR is to toggle the bit. If it is clear, then the ADD has
- // no effect.
- if ((AddRHS & AndRHSV) == 0) { // Bit is not set, noop
- TheAnd.setOperand(0, X);
- return &TheAnd;
- } else {
- // Pull the XOR out of the AND.
- Value *NewAnd = Builder->CreateAnd(X, AndRHS);
- NewAnd->takeName(Op);
- return BinaryOperator::CreateXor(NewAnd, AndRHS);
- }
- }
- }
- }
- break;
- case Instruction::Shl: {
- // We know that the AND will not produce any of the bits shifted in, so if
- // the anded constant includes them, clear them now!
- //
- uint32_t BitWidth = AndRHS->getType()->getBitWidth();
- uint32_t OpRHSVal = OpRHS->getLimitedValue(BitWidth);
- APInt ShlMask(APInt::getHighBitsSet(BitWidth, BitWidth-OpRHSVal));
- ConstantInt *CI = ConstantInt::get(AndRHS->getContext(),
- AndRHS->getValue() & ShlMask);
+Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
+ SmallVector<Value*, 8> Ops(GEP.op_begin(), GEP.op_end());
- if (CI->getValue() == ShlMask) {
- // Masking out bits that the shift already masks
- return ReplaceInstUsesWith(TheAnd, Op); // No need for the and.
- } else if (CI != AndRHS) { // Reducing bits set in and.
- TheAnd.setOperand(1, CI);
- return &TheAnd;
- }
- break;
- }
- case Instruction::LShr: {
- // We know that the AND will not produce any of the bits shifted in, so if
- // the anded constant includes them, clear them now! This only applies to
- // unsigned shifts, because a signed shr may bring in set bits!
- //
- uint32_t BitWidth = AndRHS->getType()->getBitWidth();
- uint32_t OpRHSVal = OpRHS->getLimitedValue(BitWidth);
- APInt ShrMask(APInt::getLowBitsSet(BitWidth, BitWidth - OpRHSVal));
- ConstantInt *CI = ConstantInt::get(Op->getContext(),
- AndRHS->getValue() & ShrMask);
+ if (Value *V = SimplifyGEPInst(&Ops[0], Ops.size(), TD))
+ return ReplaceInstUsesWith(GEP, V);
- if (CI->getValue() == ShrMask) {
- // Masking out bits that the shift already masks.
- return ReplaceInstUsesWith(TheAnd, Op);
- } else if (CI != AndRHS) {
- TheAnd.setOperand(1, CI); // Reduce bits set in and cst.
- return &TheAnd;
- }
- break;
- }
- case Instruction::AShr:
- // Signed shr.
- // See if this is shifting in some sign extension, then masking it out
- // with an and.
- if (Op->hasOneUse()) {
- uint32_t BitWidth = AndRHS->getType()->getBitWidth();
- uint32_t OpRHSVal = OpRHS->getLimitedValue(BitWidth);
- APInt ShrMask(APInt::getLowBitsSet(BitWidth, BitWidth - OpRHSVal));
- Constant *C = ConstantInt::get(Op->getContext(),
- AndRHS->getValue() & ShrMask);
- if (C == AndRHS) { // Masking out bits shifted in.
- // (Val ashr C1) & C2 -> (Val lshr C1) & C2
- // Make the argument unsigned.
- Value *ShVal = Op->getOperand(0);
- ShVal = Builder->CreateLShr(ShVal, OpRHS, Op->getName());
- return BinaryOperator::CreateAnd(ShVal, AndRHS, TheAnd.getName());
- }
- }
- break;
- }
- return 0;
-}
+ Value *PtrOp = GEP.getOperand(0);
+ if (isa<UndefValue>(GEP.getOperand(0)))
+ return ReplaceInstUsesWith(GEP, UndefValue::get(GEP.getType()));
-/// InsertRangeTest - Emit a computation of: (V >= Lo && V < Hi) if Inside is
-/// true, otherwise (V < Lo || V >= Hi). In pratice, we emit the more efficient
-/// (V-Lo) <u Hi-Lo. This method expects that Lo <= Hi. isSigned indicates
-/// whether to treat the V, Lo and HI as signed or not. IB is the location to
-/// insert new instructions.
-Instruction *InstCombiner::InsertRangeTest(Value *V, Constant *Lo, Constant *Hi,
- bool isSigned, bool Inside,
- Instruction &IB) {
- assert(cast<ConstantInt>(ConstantExpr::getICmp((isSigned ?
- ICmpInst::ICMP_SLE:ICmpInst::ICMP_ULE), Lo, Hi))->getZExtValue() &&
- "Lo is not <= Hi in range emission code!");
+ // Eliminate unneeded casts for indices.
+ if (TD) {
+ bool MadeChange = false;
+ unsigned PtrSize = TD->getPointerSizeInBits();
- if (Inside) {
- if (Lo == Hi) // Trivially false.
- return new ICmpInst(ICmpInst::ICMP_NE, V, V);
-
- // V >= Min && V < Hi --> V < Hi
- if (cast<ConstantInt>(Lo)->isMinValue(isSigned)) {
- ICmpInst::Predicate pred = (isSigned ?
- ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT);
- return new ICmpInst(pred, V, Hi);
+ gep_type_iterator GTI = gep_type_begin(GEP);
+ for (User::op_iterator I = GEP.op_begin() + 1, E = GEP.op_end();
+ I != E; ++I, ++GTI) {
+ if (!isa<SequentialType>(*GTI)) continue;
+
+ // If we are using a wider index than needed for this platform, shrink it
+ // to what we need. If narrower, sign-extend it to what we need. This
+ // explicit cast can make subsequent optimizations more obvious.
+ unsigned OpBits = cast<IntegerType>((*I)->getType())->getBitWidth();
+ if (OpBits == PtrSize)
+ continue;
+
+ *I = Builder->CreateIntCast(*I, TD->getIntPtrType(GEP.getContext()),true);
+ MadeChange = true;
}
-
- // Emit V-Lo <u Hi-Lo
- Constant *NegLo = ConstantExpr::getNeg(Lo);
- Value *Add = Builder->CreateAdd(V, NegLo, V->getName()+".off");
- Constant *UpperBound = ConstantExpr::getAdd(NegLo, Hi);
- return new ICmpInst(ICmpInst::ICMP_ULT, Add, UpperBound);
- }
-
- if (Lo == Hi) // Trivially true.
- return new ICmpInst(ICmpInst::ICMP_EQ, V, V);
-
- // V < Min || V >= Hi -> V > Hi-1
- Hi = SubOne(cast<ConstantInt>(Hi));
- if (cast<ConstantInt>(Lo)->isMinValue(isSigned)) {
- ICmpInst::Predicate pred = (isSigned ?
- ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT);
- return new ICmpInst(pred, V, Hi);
+ if (MadeChange) return &GEP;
}
- // Emit V-Lo >u Hi-1-Lo
- // Note that Hi has already had one subtracted from it, above.
- ConstantInt *NegLo = cast<ConstantInt>(ConstantExpr::getNeg(Lo));
- Value *Add = Builder->CreateAdd(V, NegLo, V->getName()+".off");
- Constant *LowerBound = ConstantExpr::getAdd(NegLo, Hi);
- return new ICmpInst(ICmpInst::ICMP_UGT, Add, LowerBound);
-}
-
-// isRunOfOnes - Returns true iff Val consists of one contiguous run of 1s with
-// any number of 0s on either side. The 1s are allowed to wrap from LSB to
-// MSB, so 0x000FFF0, 0x0000FFFF, and 0xFF0000FF are all runs. 0x0F0F0000 is
-// not, since all 1s are not contiguous.
-static bool isRunOfOnes(ConstantInt *Val, uint32_t &MB, uint32_t &ME) {
- const APInt& V = Val->getValue();
- uint32_t BitWidth = Val->getType()->getBitWidth();
- if (!APIntOps::isShiftedMask(BitWidth, V)) return false;
-
- // look for the first zero bit after the run of ones
- MB = BitWidth - ((V - 1) ^ V).countLeadingZeros();
- // look for the first non-zero bit
- ME = V.getActiveBits();
- return true;
-}
+ // 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.
+ //
+ if (GEPOperator *Src = dyn_cast<GEPOperator>(PtrOp)) {
+ // Note that if our source is a gep chain itself that we wait for that
+ // chain to be resolved before we perform this transformation. This
+ // avoids us creating a TON of code in some cases.
+ //
+ if (GetElementPtrInst *SrcGEP =
+ dyn_cast<GetElementPtrInst>(Src->getOperand(0)))
+ if (SrcGEP->getNumOperands() == 2)
+ return 0; // Wait until our source is folded to completion.
-/// FoldLogicalPlusAnd - This is part of an expression (LHS +/- RHS) & Mask,
-/// where isSub determines whether the operator is a sub. If we can fold one of
-/// the following xforms:
-///
-/// ((A & N) +/- B) & Mask -> (A +/- B) & Mask iff N&Mask == Mask
-/// ((A | N) +/- B) & Mask -> (A +/- B) & Mask iff N&Mask == 0
-/// ((A ^ N) +/- B) & Mask -> (A +/- B) & Mask iff N&Mask == 0
-///
-/// return (A +/- B).
-///
-Value *InstCombiner::FoldLogicalPlusAnd(Value *LHS, Value *RHS,
- ConstantInt *Mask, bool isSub,
- Instruction &I) {
- Instruction *LHSI = dyn_cast<Instruction>(LHS);
- if (!LHSI || LHSI->getNumOperands() != 2 ||
- !isa<ConstantInt>(LHSI->getOperand(1))) return 0;
+ SmallVector<Value*, 8> Indices;
- ConstantInt *N = cast<ConstantInt>(LHSI->getOperand(1));
+ // Find out whether the last index in the source GEP is a sequential idx.
+ bool EndsWithSequential = false;
+ for (gep_type_iterator I = gep_type_begin(*Src), E = gep_type_end(*Src);
+ I != E; ++I)
+ EndsWithSequential = !isa<StructType>(*I);
- switch (LHSI->getOpcode()) {
- default: return 0;
- case Instruction::And:
- if (ConstantExpr::getAnd(N, Mask) == Mask) {
- // If the AndRHS is a power of two minus one (0+1+), this is simple.
- if ((Mask->getValue().countLeadingZeros() +
- Mask->getValue().countPopulation()) ==
- Mask->getValue().getBitWidth())
- break;
+ // Can we combine the two pointer arithmetics offsets?
+ if (EndsWithSequential) {
+ // Replace: gep (gep %P, long B), long A, ...
+ // With: T = long A+B; gep %P, T, ...
+ //
+ Value *Sum;
+ Value *SO1 = Src->getOperand(Src->getNumOperands()-1);
+ Value *GO1 = GEP.getOperand(1);
+ if (SO1 == Constant::getNullValue(SO1->getType())) {
+ Sum = GO1;
+ } else if (GO1 == Constant::getNullValue(GO1->getType())) {
+ Sum = SO1;
+ } else {
+ // If they aren't the same type, then the input hasn't been processed
+ // by the loop above yet (which canonicalizes sequential index types to
+ // intptr_t). Just avoid transforming this until the input has been
+ // normalized.
+ if (SO1->getType() != GO1->getType())
+ return 0;
+ Sum = Builder->CreateAdd(SO1, GO1, PtrOp->getName()+".sum");
+ }
- // Otherwise, if Mask is 0+1+0+, and if B is known to have the low 0+
- // part, we don't need any explicit masks to take them out of A. If that
- // is all N is, ignore it.
- uint32_t MB = 0, ME = 0;
- if (isRunOfOnes(Mask, MB, ME)) { // begin/end bit of run, inclusive
- uint32_t BitWidth = cast<IntegerType>(RHS->getType())->getBitWidth();
- APInt Mask(APInt::getLowBitsSet(BitWidth, MB-1));
- if (MaskedValueIsZero(RHS, Mask))
- break;
+ // Update the GEP in place if possible.
+ if (Src->getNumOperands() == 2) {
+ GEP.setOperand(0, Src->getOperand(0));
+ GEP.setOperand(1, Sum);
+ return &GEP;
}
+ Indices.append(Src->op_begin()+1, Src->op_end()-1);
+ Indices.push_back(Sum);
+ Indices.append(GEP.op_begin()+2, GEP.op_end());
+ } else if (isa<Constant>(*GEP.idx_begin()) &&
+ cast<Constant>(*GEP.idx_begin())->isNullValue() &&
+ Src->getNumOperands() != 1) {
+ // Otherwise we can do the fold if the first index of the GEP is a zero
+ Indices.append(Src->op_begin()+1, Src->op_end());
+ Indices.append(GEP.idx_begin()+1, GEP.idx_end());
}
- return 0;
- case Instruction::Or:
- case Instruction::Xor:
- // If the AndRHS is a power of two minus one (0+1+), and N&Mask == 0
- if ((Mask->getValue().countLeadingZeros() +
- Mask->getValue().countPopulation()) == Mask->getValue().getBitWidth()
- && ConstantExpr::getAnd(N, Mask)->isNullValue())
- break;
- return 0;
- }
-
- if (isSub)
- return Builder->CreateSub(LHSI->getOperand(0), RHS, "fold");
- return Builder->CreateAdd(LHSI->getOperand(0), RHS, "fold");
-}
-/// FoldAndOfICmps - Fold (icmp)&(icmp) if possible.
-Instruction *InstCombiner::FoldAndOfICmps(Instruction &I,
- ICmpInst *LHS, ICmpInst *RHS) {
- ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
-
- // (icmp1 A, B) & (icmp2 A, B) --> (icmp3 A, B)
- if (PredicatesFoldable(LHSCC, RHSCC)) {
- if (LHS->getOperand(0) == RHS->getOperand(1) &&
- LHS->getOperand(1) == RHS->getOperand(0))
- LHS->swapOperands();
- if (LHS->getOperand(0) == RHS->getOperand(0) &&
- LHS->getOperand(1) == RHS->getOperand(1)) {
- Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
- unsigned Code = getICmpCode(LHS) & getICmpCode(RHS);
- bool isSigned = LHS->isSigned() || RHS->isSigned();
- Value *RV = getICmpValue(isSigned, Code, Op0, Op1);
- if (Instruction *I = dyn_cast<Instruction>(RV))
- return I;
- // Otherwise, it's a constant boolean value.
- return ReplaceInstUsesWith(I, RV);
- }
- }
-
- // This only handles icmp of constants: (icmp1 A, C1) & (icmp2 B, C2).
- Value *Val = LHS->getOperand(0), *Val2 = RHS->getOperand(0);
- ConstantInt *LHSCst = dyn_cast<ConstantInt>(LHS->getOperand(1));
- ConstantInt *RHSCst = dyn_cast<ConstantInt>(RHS->getOperand(1));
- if (LHSCst == 0 || RHSCst == 0) return 0;
-
- if (LHSCst == RHSCst && LHSCC == RHSCC) {
- // (icmp ult A, C) & (icmp ult B, C) --> (icmp ult (A|B), C)
- // where C is a power of 2
- if (LHSCC == ICmpInst::ICMP_ULT &&
- LHSCst->getValue().isPowerOf2()) {
- Value *NewOr = Builder->CreateOr(Val, Val2);
- return new ICmpInst(LHSCC, NewOr, LHSCst);
- }
-
- // (icmp eq A, 0) & (icmp eq B, 0) --> (icmp eq (A|B), 0)
- if (LHSCC == ICmpInst::ICMP_EQ && LHSCst->isZero()) {
- Value *NewOr = Builder->CreateOr(Val, Val2);
- return new ICmpInst(LHSCC, NewOr, LHSCst);
- }
+ if (!Indices.empty())
+ return (GEP.isInBounds() && Src->isInBounds()) ?
+ GetElementPtrInst::CreateInBounds(Src->getOperand(0), Indices.begin(),
+ Indices.end(), GEP.getName()) :
+ GetElementPtrInst::Create(Src->getOperand(0), Indices.begin(),
+ Indices.end(), GEP.getName());
}
- // From here on, we only handle:
- // (icmp1 A, C1) & (icmp2 A, C2) --> something simpler.
- if (Val != Val2) return 0;
-
- // ICMP_[US][GL]E X, CST is folded to ICMP_[US][GL]T elsewhere.
- if (LHSCC == ICmpInst::ICMP_UGE || LHSCC == ICmpInst::ICMP_ULE ||
- RHSCC == ICmpInst::ICMP_UGE || RHSCC == ICmpInst::ICMP_ULE ||
- LHSCC == ICmpInst::ICMP_SGE || LHSCC == ICmpInst::ICMP_SLE ||
- RHSCC == ICmpInst::ICMP_SGE || RHSCC == ICmpInst::ICMP_SLE)
- return 0;
-
- // We can't fold (ugt x, C) & (sgt x, C2).
- if (!PredicatesFoldable(LHSCC, RHSCC))
- return 0;
-
- // Ensure that the larger constant is on the RHS.
- bool ShouldSwap;
- if (CmpInst::isSigned(LHSCC) ||
- (ICmpInst::isEquality(LHSCC) &&
- CmpInst::isSigned(RHSCC)))
- ShouldSwap = LHSCst->getValue().sgt(RHSCst->getValue());
- else
- ShouldSwap = LHSCst->getValue().ugt(RHSCst->getValue());
-
- if (ShouldSwap) {
- std::swap(LHS, RHS);
- std::swap(LHSCst, RHSCst);
- std::swap(LHSCC, RHSCC);
- }
-
- // At this point, we know we have have two icmp instructions
- // comparing a value against two constants and and'ing the result
- // together. Because of the above check, we know that we only have
- // icmp eq, icmp ne, icmp [su]lt, and icmp [SU]gt here. We also know
- // (from the icmp folding check above), that the two constants
- // are not equal and that the larger constant is on the RHS
- assert(LHSCst != RHSCst && "Compares not folded above?");
+ // Handle gep(bitcast x) and gep(gep x, 0, 0, 0).
+ Value *StrippedPtr = PtrOp->stripPointerCasts();
+ if (StrippedPtr != PtrOp) {
+ const PointerType *StrippedPtrTy =cast<PointerType>(StrippedPtr->getType());
- switch (LHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ:
- switch (RHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X == 13 & X == 15) -> false
- case ICmpInst::ICMP_UGT: // (X == 13 & X > 15) -> false
- case ICmpInst::ICMP_SGT: // (X == 13 & X > 15) -> false
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
- case ICmpInst::ICMP_NE: // (X == 13 & X != 15) -> X == 13
- case ICmpInst::ICMP_ULT: // (X == 13 & X < 15) -> X == 13
- case ICmpInst::ICMP_SLT: // (X == 13 & X < 15) -> X == 13
- return ReplaceInstUsesWith(I, LHS);
- }
- case ICmpInst::ICMP_NE:
- switch (RHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_ULT:
- if (LHSCst == SubOne(RHSCst)) // (X != 13 & X u< 14) -> X < 13
- return new ICmpInst(ICmpInst::ICMP_ULT, Val, LHSCst);
- break; // (X != 13 & X u< 15) -> no change
- case ICmpInst::ICMP_SLT:
- if (LHSCst == SubOne(RHSCst)) // (X != 13 & X s< 14) -> X < 13
- return new ICmpInst(ICmpInst::ICMP_SLT, Val, LHSCst);
- break; // (X != 13 & X s< 15) -> no change
- case ICmpInst::ICMP_EQ: // (X != 13 & X == 15) -> X == 15
- case ICmpInst::ICMP_UGT: // (X != 13 & X u> 15) -> X u> 15
- case ICmpInst::ICMP_SGT: // (X != 13 & X s> 15) -> X s> 15
- return ReplaceInstUsesWith(I, RHS);
- case ICmpInst::ICMP_NE:
- if (LHSCst == SubOne(RHSCst)){// (X != 13 & X != 14) -> X-13 >u 1
- Constant *AddCST = ConstantExpr::getNeg(LHSCst);
- Value *Add = Builder->CreateAdd(Val, AddCST, Val->getName()+".off");
- return new ICmpInst(ICmpInst::ICMP_UGT, Add,
- ConstantInt::get(Add->getType(), 1));
- }
- break; // (X != 13 & X != 15) -> no change
- }
- break;
- case ICmpInst::ICMP_ULT:
- switch (RHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X u< 13 & X == 15) -> false
- case ICmpInst::ICMP_UGT: // (X u< 13 & X u> 15) -> false
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
- case ICmpInst::ICMP_SGT: // (X u< 13 & X s> 15) -> no change
- break;
- case ICmpInst::ICMP_NE: // (X u< 13 & X != 15) -> X u< 13
- case ICmpInst::ICMP_ULT: // (X u< 13 & X u< 15) -> X u< 13
- return ReplaceInstUsesWith(I, LHS);
- case ICmpInst::ICMP_SLT: // (X u< 13 & X s< 15) -> no change
- break;
- }
- break;
- case ICmpInst::ICMP_SLT:
- switch (RHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X s< 13 & X == 15) -> false
- case ICmpInst::ICMP_SGT: // (X s< 13 & X s> 15) -> false
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
- case ICmpInst::ICMP_UGT: // (X s< 13 & X u> 15) -> no change
- break;
- case ICmpInst::ICMP_NE: // (X s< 13 & X != 15) -> X < 13
- case ICmpInst::ICMP_SLT: // (X s< 13 & X s< 15) -> X < 13
- return ReplaceInstUsesWith(I, LHS);
- case ICmpInst::ICMP_ULT: // (X s< 13 & X u< 15) -> no change
- break;
- }
- break;
- case ICmpInst::ICMP_UGT:
- switch (RHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X u> 13 & X == 15) -> X == 15
- case ICmpInst::ICMP_UGT: // (X u> 13 & X u> 15) -> X u> 15
- return ReplaceInstUsesWith(I, RHS);
- case ICmpInst::ICMP_SGT: // (X u> 13 & X s> 15) -> no change
- break;
- case ICmpInst::ICMP_NE:
- if (RHSCst == AddOne(LHSCst)) // (X u> 13 & X != 14) -> X u> 14
- return new ICmpInst(LHSCC, Val, RHSCst);
- break; // (X u> 13 & X != 15) -> no change
- case ICmpInst::ICMP_ULT: // (X u> 13 & X u< 15) -> (X-14) <u 1
- return InsertRangeTest(Val, AddOne(LHSCst),
- RHSCst, false, true, I);
- case ICmpInst::ICMP_SLT: // (X u> 13 & X s< 15) -> no change
- break;
- }
- break;
- case ICmpInst::ICMP_SGT:
- switch (RHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X s> 13 & X == 15) -> X == 15
- case ICmpInst::ICMP_SGT: // (X s> 13 & X s> 15) -> X s> 15
- return ReplaceInstUsesWith(I, RHS);
- case ICmpInst::ICMP_UGT: // (X s> 13 & X u> 15) -> no change
- break;
- case ICmpInst::ICMP_NE:
- if (RHSCst == AddOne(LHSCst)) // (X s> 13 & X != 14) -> X s> 14
- return new ICmpInst(LHSCC, Val, RHSCst);
- break; // (X s> 13 & X != 15) -> no change
- case ICmpInst::ICMP_SLT: // (X s> 13 & X s< 15) -> (X-14) s< 1
- return InsertRangeTest(Val, AddOne(LHSCst),
- RHSCst, true, true, I);
- case ICmpInst::ICMP_ULT: // (X s> 13 & X u< 15) -> no change
- break;
- }
- break;
- }
-
- return 0;
-}
-
-Instruction *InstCombiner::FoldAndOfFCmps(Instruction &I, FCmpInst *LHS,
- FCmpInst *RHS) {
-
- if (LHS->getPredicate() == FCmpInst::FCMP_ORD &&
- RHS->getPredicate() == FCmpInst::FCMP_ORD) {
- // (fcmp ord x, c) & (fcmp ord y, c) -> (fcmp ord x, y)
- if (ConstantFP *LHSC = dyn_cast<ConstantFP>(LHS->getOperand(1)))
- if (ConstantFP *RHSC = dyn_cast<ConstantFP>(RHS->getOperand(1))) {
- // If either of the constants are nans, then the whole thing returns
- // false.
- if (LHSC->getValueAPF().isNaN() || RHSC->getValueAPF().isNaN())
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
- return new FCmpInst(FCmpInst::FCMP_ORD,
- LHS->getOperand(0), RHS->getOperand(0));
- }
-
- // Handle vector zeros. This occurs because the canonical form of
- // "fcmp ord x,x" is "fcmp ord x, 0".
- if (isa<ConstantAggregateZero>(LHS->getOperand(1)) &&
- isa<ConstantAggregateZero>(RHS->getOperand(1)))
- return new FCmpInst(FCmpInst::FCMP_ORD,
- LHS->getOperand(0), RHS->getOperand(0));
- return 0;
- }
-
- Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1);
- Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1);
- FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate();
-
-
- if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) {
- // Swap RHS operands to match LHS.
- Op1CC = FCmpInst::getSwappedPredicate(Op1CC);
- std::swap(Op1LHS, Op1RHS);
- }
-
- if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) {
- // Simplify (fcmp cc0 x, y) & (fcmp cc1 x, y).
- if (Op0CC == Op1CC)
- return new FCmpInst((FCmpInst::Predicate)Op0CC, Op0LHS, Op0RHS);
-
- if (Op0CC == FCmpInst::FCMP_FALSE || Op1CC == FCmpInst::FCMP_FALSE)
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
- if (Op0CC == FCmpInst::FCMP_TRUE)
- return ReplaceInstUsesWith(I, RHS);
- if (Op1CC == FCmpInst::FCMP_TRUE)
- return ReplaceInstUsesWith(I, LHS);
-
- bool Op0Ordered;
- bool Op1Ordered;
- unsigned Op0Pred = getFCmpCode(Op0CC, Op0Ordered);
- unsigned Op1Pred = getFCmpCode(Op1CC, Op1Ordered);
- if (Op1Pred == 0) {
- std::swap(LHS, RHS);
- std::swap(Op0Pred, Op1Pred);
- std::swap(Op0Ordered, Op1Ordered);
- }
- if (Op0Pred == 0) {
- // uno && ueq -> uno && (uno || eq) -> ueq
- // ord && olt -> ord && (ord && lt) -> olt
- if (Op0Ordered == Op1Ordered)
- return ReplaceInstUsesWith(I, RHS);
-
- // uno && oeq -> uno && (ord && eq) -> false
- // uno && ord -> false
- if (!Op0Ordered)
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
- // ord && ueq -> ord && (uno || eq) -> oeq
- return cast<Instruction>(getFCmpValue(true, Op1Pred, Op0LHS, Op0RHS));
- }
- }
-
- return 0;
-}
-
-
-Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
- bool Changed = SimplifyCommutative(I);
- Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-
- if (Value *V = SimplifyAndInst(Op0, Op1, TD))
- return ReplaceInstUsesWith(I, V);
-
- // See if we can simplify any instructions used by the instruction whose sole
- // purpose is to compute bits we don't care about.
- if (SimplifyDemandedInstructionBits(I))
- return &I;
-
- if (ConstantInt *AndRHS = dyn_cast<ConstantInt>(Op1)) {
- const APInt &AndRHSMask = AndRHS->getValue();
- APInt NotAndRHS(~AndRHSMask);
-
- // Optimize a variety of ((val OP C1) & C2) combinations...
- if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
- Value *Op0LHS = Op0I->getOperand(0);
- Value *Op0RHS = Op0I->getOperand(1);
- switch (Op0I->getOpcode()) {
- default: break;
- case Instruction::Xor:
- case Instruction::Or:
- // If the mask is only needed on one incoming arm, push it up.
- if (!Op0I->hasOneUse()) break;
-
- if (MaskedValueIsZero(Op0LHS, NotAndRHS)) {
- // Not masking anything out for the LHS, move to RHS.
- Value *NewRHS = Builder->CreateAnd(Op0RHS, AndRHS,
- Op0RHS->getName()+".masked");
- return BinaryOperator::Create(Op0I->getOpcode(), Op0LHS, NewRHS);
- }
- if (!isa<Constant>(Op0RHS) &&
- MaskedValueIsZero(Op0RHS, NotAndRHS)) {
- // Not masking anything out for the RHS, move to LHS.
- Value *NewLHS = Builder->CreateAnd(Op0LHS, AndRHS,
- Op0LHS->getName()+".masked");
- return BinaryOperator::Create(Op0I->getOpcode(), NewLHS, Op0RHS);
- }
-
- break;
- case Instruction::Add:
- // ((A & N) + B) & AndRHS -> (A + B) & AndRHS iff N&AndRHS == AndRHS.
- // ((A | N) + B) & AndRHS -> (A + B) & AndRHS iff N&AndRHS == 0
- // ((A ^ N) + B) & AndRHS -> (A + B) & AndRHS iff N&AndRHS == 0
- if (Value *V = FoldLogicalPlusAnd(Op0LHS, Op0RHS, AndRHS, false, I))
- return BinaryOperator::CreateAnd(V, AndRHS);
- if (Value *V = FoldLogicalPlusAnd(Op0RHS, Op0LHS, AndRHS, false, I))
- return BinaryOperator::CreateAnd(V, AndRHS); // Add commutes
- break;
-
- case Instruction::Sub:
- // ((A & N) - B) & AndRHS -> (A - B) & AndRHS iff N&AndRHS == AndRHS.
- // ((A | N) - B) & AndRHS -> (A - B) & AndRHS iff N&AndRHS == 0
- // ((A ^ N) - B) & AndRHS -> (A - B) & AndRHS iff N&AndRHS == 0
- if (Value *V = FoldLogicalPlusAnd(Op0LHS, Op0RHS, AndRHS, true, I))
- return BinaryOperator::CreateAnd(V, AndRHS);
-
- // (A - N) & AndRHS -> -N & AndRHS iff A&AndRHS==0 and AndRHS
- // has 1's for all bits that the subtraction with A might affect.
- if (Op0I->hasOneUse()) {
- uint32_t BitWidth = AndRHSMask.getBitWidth();
- uint32_t Zeros = AndRHSMask.countLeadingZeros();
- APInt Mask = APInt::getLowBitsSet(BitWidth, BitWidth - Zeros);
-
- ConstantInt *A = dyn_cast<ConstantInt>(Op0LHS);
- if (!(A && A->isZero()) && // avoid infinite recursion.
- MaskedValueIsZero(Op0LHS, Mask)) {
- Value *NewNeg = Builder->CreateNeg(Op0RHS);
- return BinaryOperator::CreateAnd(NewNeg, AndRHS);
- }
- }
- break;
-
- case Instruction::Shl:
- case Instruction::LShr:
- // (1 << x) & 1 --> zext(x == 0)
- // (1 >> x) & 1 --> zext(x == 0)
- if (AndRHSMask == 1 && Op0LHS == AndRHS) {
- Value *NewICmp =
- Builder->CreateICmpEQ(Op0RHS, Constant::getNullValue(I.getType()));
- return new ZExtInst(NewICmp, I.getType());
- }
- break;
- }
-
- if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1)))
- if (Instruction *Res = OptAndOp(Op0I, Op0CI, AndRHS, I))
- return Res;
- } else if (CastInst *CI = dyn_cast<CastInst>(Op0)) {
- // If this is an integer truncation or change from signed-to-unsigned, and
- // if the source is an and/or with immediate, transform it. This
- // frequently occurs for bitfield accesses.
- if (Instruction *CastOp = dyn_cast<Instruction>(CI->getOperand(0))) {
- if ((isa<TruncInst>(CI) || isa<BitCastInst>(CI)) &&
- CastOp->getNumOperands() == 2)
- if (ConstantInt *AndCI =dyn_cast<ConstantInt>(CastOp->getOperand(1))){
- if (CastOp->getOpcode() == Instruction::And) {
- // Change: and (cast (and X, C1) to T), C2
- // into : and (cast X to T), trunc_or_bitcast(C1)&C2
- // This will fold the two constants together, which may allow
- // other simplifications.
- Value *NewCast = Builder->CreateTruncOrBitCast(
- CastOp->getOperand(0), I.getType(),
- CastOp->getName()+".shrunk");
- // trunc_or_bitcast(C1)&C2
- Constant *C3 = ConstantExpr::getTruncOrBitCast(AndCI,I.getType());
- C3 = ConstantExpr::getAnd(C3, AndRHS);
- return BinaryOperator::CreateAnd(NewCast, C3);
- } else if (CastOp->getOpcode() == Instruction::Or) {
- // Change: and (cast (or X, C1) to T), C2
- // into : trunc(C1)&C2 iff trunc(C1)&C2 == C2
- Constant *C3 = ConstantExpr::getTruncOrBitCast(AndCI,I.getType());
- if (ConstantExpr::getAnd(C3, AndRHS) == AndRHS)
- // trunc(C1)&C2
- return ReplaceInstUsesWith(I, AndRHS);
- }
- }
- }
- }
-
- // Try to fold constant and into select arguments.
- if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
- if (Instruction *R = FoldOpIntoSelect(I, SI))
- return R;
- if (isa<PHINode>(Op0))
- if (Instruction *NV = FoldOpIntoPhi(I))
- return NV;
- }
-
-
- // (~A & ~B) == (~(A | B)) - De Morgan's Law
- if (Value *Op0NotVal = dyn_castNotVal(Op0))
- if (Value *Op1NotVal = dyn_castNotVal(Op1))
- if (Op0->hasOneUse() && Op1->hasOneUse()) {
- Value *Or = Builder->CreateOr(Op0NotVal, Op1NotVal,
- I.getName()+".demorgan");
- return BinaryOperator::CreateNot(Or);
- }
-
- {
- Value *A = 0, *B = 0, *C = 0, *D = 0;
- // (A|B) & ~(A&B) -> A^B
- if (match(Op0, m_Or(m_Value(A), m_Value(B))) &&
- match(Op1, m_Not(m_And(m_Value(C), m_Value(D)))) &&
- ((A == C && B == D) || (A == D && B == C)))
- return BinaryOperator::CreateXor(A, B);
-
- // ~(A&B) & (A|B) -> A^B
- if (match(Op1, m_Or(m_Value(A), m_Value(B))) &&
- match(Op0, m_Not(m_And(m_Value(C), m_Value(D)))) &&
- ((A == C && B == D) || (A == D && B == C)))
- return BinaryOperator::CreateXor(A, B);
-
- if (Op0->hasOneUse() &&
- match(Op0, m_Xor(m_Value(A), m_Value(B)))) {
- if (A == Op1) { // (A^B)&A -> A&(A^B)
- I.swapOperands(); // Simplify below
- std::swap(Op0, Op1);
- } else if (B == Op1) { // (A^B)&B -> B&(B^A)
- cast<BinaryOperator>(Op0)->swapOperands();
- I.swapOperands(); // Simplify below
- std::swap(Op0, Op1);
- }
- }
-
- if (Op1->hasOneUse() &&
- match(Op1, m_Xor(m_Value(A), m_Value(B)))) {
- if (B == Op0) { // B&(A^B) -> B&(B^A)
- cast<BinaryOperator>(Op1)->swapOperands();
- std::swap(A, B);
- }
- if (A == Op0) // A&(A^B) -> A & ~B
- return BinaryOperator::CreateAnd(A, Builder->CreateNot(B, "tmp"));
- }
-
- // (A&((~A)|B)) -> A&B
- if (match(Op0, m_Or(m_Not(m_Specific(Op1)), m_Value(A))) ||
- match(Op0, m_Or(m_Value(A), m_Not(m_Specific(Op1)))))
- return BinaryOperator::CreateAnd(A, Op1);
- if (match(Op1, m_Or(m_Not(m_Specific(Op0)), m_Value(A))) ||
- match(Op1, m_Or(m_Value(A), m_Not(m_Specific(Op0)))))
- return BinaryOperator::CreateAnd(A, Op0);
- }
-
- if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1))
- if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0))
- if (Instruction *Res = FoldAndOfICmps(I, LHS, RHS))
- return Res;
-
- // fold (and (cast A), (cast B)) -> (cast (and A, B))
- if (CastInst *Op0C = dyn_cast<CastInst>(Op0))
- if (CastInst *Op1C = dyn_cast<CastInst>(Op1))
- if (Op0C->getOpcode() == Op1C->getOpcode()) { // same cast kind ?
- const Type *SrcTy = Op0C->getOperand(0)->getType();
- if (SrcTy == Op1C->getOperand(0)->getType() &&
- SrcTy->isIntOrIntVector() &&
- // Only do this if the casts both really cause code to be generated.
- ValueRequiresCast(Op0C->getOpcode(), Op0C->getOperand(0),
- I.getType()) &&
- ValueRequiresCast(Op1C->getOpcode(), Op1C->getOperand(0),
- I.getType())) {
- Value *NewOp = Builder->CreateAnd(Op0C->getOperand(0),
- Op1C->getOperand(0), I.getName());
- return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
- }
- }
-
- // (X >> Z) & (Y >> Z) -> (X&Y) >> Z for all shifts.
- if (BinaryOperator *SI1 = dyn_cast<BinaryOperator>(Op1)) {
- if (BinaryOperator *SI0 = dyn_cast<BinaryOperator>(Op0))
- if (SI0->isShift() && SI0->getOpcode() == SI1->getOpcode() &&
- SI0->getOperand(1) == SI1->getOperand(1) &&
- (SI0->hasOneUse() || SI1->hasOneUse())) {
- Value *NewOp =
- Builder->CreateAnd(SI0->getOperand(0), SI1->getOperand(0),
- SI0->getName());
- return BinaryOperator::Create(SI1->getOpcode(), NewOp,
- SI1->getOperand(1));
- }
- }
-
- // If and'ing two fcmp, try combine them into one.
- if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0))) {
- if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
- if (Instruction *Res = FoldAndOfFCmps(I, LHS, RHS))
- return Res;
- }
-
- return Changed ? &I : 0;
-}
-
-/// CollectBSwapParts - Analyze the specified subexpression and see if it is
-/// capable of providing pieces of a bswap. The subexpression provides pieces
-/// of a bswap if it is proven that each of the non-zero bytes in the output of
-/// the expression came from the corresponding "byte swapped" byte in some other
-/// value. For example, if the current subexpression is "(shl i32 %X, 24)" then
-/// we know that the expression deposits the low byte of %X into the high byte
-/// of the bswap result and that all other bytes are zero. This expression is
-/// accepted, the high byte of ByteValues is set to X to indicate a correct
-/// match.
-///
-/// This function returns true if the match was unsuccessful and false if so.
-/// On entry to the function the "OverallLeftShift" is a signed integer value
-/// indicating the number of bytes that the subexpression is later shifted. For
-/// example, if the expression is later right shifted by 16 bits, the
-/// OverallLeftShift value would be -2 on entry. This is used to specify which
-/// byte of ByteValues is actually being set.
-///
-/// Similarly, ByteMask is a bitmask where a bit is clear if its corresponding
-/// byte is masked to zero by a user. For example, in (X & 255), X will be
-/// processed with a bytemask of 1. Because bytemask is 32-bits, this limits
-/// this function to working on up to 32-byte (256 bit) values. ByteMask is
-/// always in the local (OverallLeftShift) coordinate space.
-///
-static bool CollectBSwapParts(Value *V, int OverallLeftShift, uint32_t ByteMask,
- SmallVector<Value*, 8> &ByteValues) {
- if (Instruction *I = dyn_cast<Instruction>(V)) {
- // If this is an or instruction, it may be an inner node of the bswap.
- if (I->getOpcode() == Instruction::Or) {
- return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask,
- ByteValues) ||
- CollectBSwapParts(I->getOperand(1), OverallLeftShift, ByteMask,
- ByteValues);
- }
-
- // If this is a logical shift by a constant multiple of 8, recurse with
- // OverallLeftShift and ByteMask adjusted.
- if (I->isLogicalShift() && isa<ConstantInt>(I->getOperand(1))) {
- unsigned ShAmt =
- cast<ConstantInt>(I->getOperand(1))->getLimitedValue(~0U);
- // Ensure the shift amount is defined and of a byte value.
- if ((ShAmt & 7) || (ShAmt > 8*ByteValues.size()))
- return true;
-
- unsigned ByteShift = ShAmt >> 3;
- if (I->getOpcode() == Instruction::Shl) {
- // X << 2 -> collect(X, +2)
- OverallLeftShift += ByteShift;
- ByteMask >>= ByteShift;
- } else {
- // X >>u 2 -> collect(X, -2)
- OverallLeftShift -= ByteShift;
- ByteMask <<= ByteShift;
- ByteMask &= (~0U >> (32-ByteValues.size()));
- }
-
- if (OverallLeftShift >= (int)ByteValues.size()) return true;
- if (OverallLeftShift <= -(int)ByteValues.size()) return true;
-
- return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask,
- ByteValues);
- }
-
- // If this is a logical 'and' with a mask that clears bytes, clear the
- // corresponding bytes in ByteMask.
- if (I->getOpcode() == Instruction::And &&
- isa<ConstantInt>(I->getOperand(1))) {
- // Scan every byte of the and mask, seeing if the byte is either 0 or 255.
- unsigned NumBytes = ByteValues.size();
- APInt Byte(I->getType()->getPrimitiveSizeInBits(), 255);
- const APInt &AndMask = cast<ConstantInt>(I->getOperand(1))->getValue();
-
- for (unsigned i = 0; i != NumBytes; ++i, Byte <<= 8) {
- // If this byte is masked out by a later operation, we don't care what
- // the and mask is.
- if ((ByteMask & (1 << i)) == 0)
- continue;
-
- // If the AndMask is all zeros for this byte, clear the bit.
- APInt MaskB = AndMask & Byte;
- if (MaskB == 0) {
- ByteMask &= ~(1U << i);
- continue;
- }
-
- // If the AndMask is not all ones for this byte, it's not a bytezap.
- if (MaskB != Byte)
- return true;
-
- // Otherwise, this byte is kept.
- }
-
- return CollectBSwapParts(I->getOperand(0), OverallLeftShift, ByteMask,
- ByteValues);
- }
- }
-
- // Okay, we got to something that isn't a shift, 'or' or 'and'. This must be
- // the input value to the bswap. Some observations: 1) if more than one byte
- // is demanded from this input, then it could not be successfully assembled
- // into a byteswap. At least one of the two bytes would not be aligned with
- // their ultimate destination.
- if (!isPowerOf2_32(ByteMask)) return true;
- unsigned InputByteNo = CountTrailingZeros_32(ByteMask);
-
- // 2) The input and ultimate destinations must line up: if byte 3 of an i32
- // is demanded, it needs to go into byte 0 of the result. This means that the
- // byte needs to be shifted until it lands in the right byte bucket. The
- // shift amount depends on the position: if the byte is coming from the high
- // part of the value (e.g. byte 3) then it must be shifted right. If from the
- // low part, it must be shifted left.
- unsigned DestByteNo = InputByteNo + OverallLeftShift;
- if (InputByteNo < ByteValues.size()/2) {
- if (ByteValues.size()-1-DestByteNo != InputByteNo)
- return true;
- } else {
- if (ByteValues.size()-1-DestByteNo != InputByteNo)
- return true;
- }
-
- // If the destination byte value is already defined, the values are or'd
- // together, which isn't a bswap (unless it's an or of the same bits).
- if (ByteValues[DestByteNo] && ByteValues[DestByteNo] != V)
- return true;
- ByteValues[DestByteNo] = V;
- return false;
-}
-
-/// MatchBSwap - Given an OR instruction, check to see if this is a bswap idiom.
-/// If so, insert the new bswap intrinsic and return it.
-Instruction *InstCombiner::MatchBSwap(BinaryOperator &I) {
- const IntegerType *ITy = dyn_cast<IntegerType>(I.getType());
- if (!ITy || ITy->getBitWidth() % 16 ||
- // ByteMask only allows up to 32-byte values.
- ITy->getBitWidth() > 32*8)
- return 0; // Can only bswap pairs of bytes. Can't do vectors.
-
- /// ByteValues - For each byte of the result, we keep track of which value
- /// defines each byte.
- SmallVector<Value*, 8> ByteValues;
- ByteValues.resize(ITy->getBitWidth()/8);
-
- // Try to find all the pieces corresponding to the bswap.
- uint32_t ByteMask = ~0U >> (32-ByteValues.size());
- if (CollectBSwapParts(&I, 0, ByteMask, ByteValues))
- return 0;
-
- // Check to see if all of the bytes come from the same value.
- Value *V = ByteValues[0];
- if (V == 0) return 0; // Didn't find a byte? Must be zero.
-
- // Check to make sure that all of the bytes come from the same value.
- for (unsigned i = 1, e = ByteValues.size(); i != e; ++i)
- if (ByteValues[i] != V)
- return 0;
- const Type *Tys[] = { ITy };
- Module *M = I.getParent()->getParent()->getParent();
- Function *F = Intrinsic::getDeclaration(M, Intrinsic::bswap, Tys, 1);
- return CallInst::Create(F, V);
-}
-
-/// MatchSelectFromAndOr - We have an expression of the form (A&C)|(B&D). Check
-/// If A is (cond?-1:0) and either B or D is ~(cond?-1,0) or (cond?0,-1), then
-/// we can simplify this expression to "cond ? C : D or B".
-static Instruction *MatchSelectFromAndOr(Value *A, Value *B,
- Value *C, Value *D) {
- // If A is not a select of -1/0, this cannot match.
- Value *Cond = 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<0, -1>(m_Specific(Cond))))
- return SelectInst::Create(Cond, C, B);
- 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<0, -1>(m_Specific(Cond))))
- return SelectInst::Create(Cond, C, D);
- if (match(B, m_Not(m_SelectCst<-1, 0>(m_Specific(Cond)))))
- return SelectInst::Create(Cond, C, D);
- return 0;
-}
-
-/// FoldOrOfICmps - Fold (icmp)|(icmp) if possible.
-Instruction *InstCombiner::FoldOrOfICmps(Instruction &I,
- ICmpInst *LHS, ICmpInst *RHS) {
- ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
-
- // (icmp1 A, B) | (icmp2 A, B) --> (icmp3 A, B)
- if (PredicatesFoldable(LHSCC, RHSCC)) {
- if (LHS->getOperand(0) == RHS->getOperand(1) &&
- LHS->getOperand(1) == RHS->getOperand(0))
- LHS->swapOperands();
- if (LHS->getOperand(0) == RHS->getOperand(0) &&
- LHS->getOperand(1) == RHS->getOperand(1)) {
- Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
- unsigned Code = getICmpCode(LHS) | getICmpCode(RHS);
- bool isSigned = LHS->isSigned() || RHS->isSigned();
- Value *RV = getICmpValue(isSigned, Code, Op0, Op1);
- if (Instruction *I = dyn_cast<Instruction>(RV))
- return I;
- // Otherwise, it's a constant boolean value.
- return ReplaceInstUsesWith(I, RV);
- }
- }
-
- // This only handles icmp of constants: (icmp1 A, C1) | (icmp2 B, C2).
- Value *Val = LHS->getOperand(0), *Val2 = RHS->getOperand(0);
- ConstantInt *LHSCst = dyn_cast<ConstantInt>(LHS->getOperand(1));
- ConstantInt *RHSCst = dyn_cast<ConstantInt>(RHS->getOperand(1));
- if (LHSCst == 0 || RHSCst == 0) return 0;
-
- // (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0)
- if (LHSCst == RHSCst && LHSCC == RHSCC &&
- LHSCC == ICmpInst::ICMP_NE && LHSCst->isZero()) {
- Value *NewOr = Builder->CreateOr(Val, Val2);
- return new ICmpInst(LHSCC, NewOr, LHSCst);
- }
-
- // From here on, we only handle:
- // (icmp1 A, C1) | (icmp2 A, C2) --> something simpler.
- if (Val != Val2) return 0;
-
- // ICMP_[US][GL]E X, CST is folded to ICMP_[US][GL]T elsewhere.
- if (LHSCC == ICmpInst::ICMP_UGE || LHSCC == ICmpInst::ICMP_ULE ||
- RHSCC == ICmpInst::ICMP_UGE || RHSCC == ICmpInst::ICMP_ULE ||
- LHSCC == ICmpInst::ICMP_SGE || LHSCC == ICmpInst::ICMP_SLE ||
- RHSCC == ICmpInst::ICMP_SGE || RHSCC == ICmpInst::ICMP_SLE)
- return 0;
-
- // We can't fold (ugt x, C) | (sgt x, C2).
- if (!PredicatesFoldable(LHSCC, RHSCC))
- return 0;
-
- // Ensure that the larger constant is on the RHS.
- bool ShouldSwap;
- if (CmpInst::isSigned(LHSCC) ||
- (ICmpInst::isEquality(LHSCC) &&
- CmpInst::isSigned(RHSCC)))
- ShouldSwap = LHSCst->getValue().sgt(RHSCst->getValue());
- else
- ShouldSwap = LHSCst->getValue().ugt(RHSCst->getValue());
-
- if (ShouldSwap) {
- std::swap(LHS, RHS);
- std::swap(LHSCst, RHSCst);
- std::swap(LHSCC, RHSCC);
- }
-
- // At this point, we know we have have two icmp instructions
- // comparing a value against two constants and or'ing the result
- // together. Because of the above check, we know that we only have
- // ICMP_EQ, ICMP_NE, ICMP_LT, and ICMP_GT here. We also know (from the
- // icmp folding check above), that the two constants are not
- // equal.
- assert(LHSCst != RHSCst && "Compares not folded above?");
-
- switch (LHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ:
- switch (RHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ:
- if (LHSCst == SubOne(RHSCst)) {
- // (X == 13 | X == 14) -> X-13 <u 2
- Constant *AddCST = ConstantExpr::getNeg(LHSCst);
- Value *Add = Builder->CreateAdd(Val, AddCST, Val->getName()+".off");
- AddCST = ConstantExpr::getSub(AddOne(RHSCst), LHSCst);
- return new ICmpInst(ICmpInst::ICMP_ULT, Add, AddCST);
- }
- break; // (X == 13 | X == 15) -> no change
- case ICmpInst::ICMP_UGT: // (X == 13 | X u> 14) -> no change
- case ICmpInst::ICMP_SGT: // (X == 13 | X s> 14) -> no change
- break;
- case ICmpInst::ICMP_NE: // (X == 13 | X != 15) -> X != 15
- case ICmpInst::ICMP_ULT: // (X == 13 | X u< 15) -> X u< 15
- case ICmpInst::ICMP_SLT: // (X == 13 | X s< 15) -> X s< 15
- return ReplaceInstUsesWith(I, RHS);
- }
- break;
- case ICmpInst::ICMP_NE:
- switch (RHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X != 13 | X == 15) -> X != 13
- case ICmpInst::ICMP_UGT: // (X != 13 | X u> 15) -> X != 13
- case ICmpInst::ICMP_SGT: // (X != 13 | X s> 15) -> X != 13
- return ReplaceInstUsesWith(I, LHS);
- case ICmpInst::ICMP_NE: // (X != 13 | X != 15) -> true
- case ICmpInst::ICMP_ULT: // (X != 13 | X u< 15) -> true
- case ICmpInst::ICMP_SLT: // (X != 13 | X s< 15) -> true
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
- }
- break;
- case ICmpInst::ICMP_ULT:
- switch (RHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X u< 13 | X == 14) -> no change
- break;
- case ICmpInst::ICMP_UGT: // (X u< 13 | X u> 15) -> (X-13) u> 2
- // If RHSCst is [us]MAXINT, it is always false. Not handling
- // this can cause overflow.
- if (RHSCst->isMaxValue(false))
- return ReplaceInstUsesWith(I, LHS);
- return InsertRangeTest(Val, LHSCst, AddOne(RHSCst),
- false, false, I);
- case ICmpInst::ICMP_SGT: // (X u< 13 | X s> 15) -> no change
- break;
- case ICmpInst::ICMP_NE: // (X u< 13 | X != 15) -> X != 15
- case ICmpInst::ICMP_ULT: // (X u< 13 | X u< 15) -> X u< 15
- return ReplaceInstUsesWith(I, RHS);
- case ICmpInst::ICMP_SLT: // (X u< 13 | X s< 15) -> no change
- break;
- }
- break;
- case ICmpInst::ICMP_SLT:
- switch (RHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X s< 13 | X == 14) -> no change
- break;
- case ICmpInst::ICMP_SGT: // (X s< 13 | X s> 15) -> (X-13) s> 2
- // If RHSCst is [us]MAXINT, it is always false. Not handling
- // this can cause overflow.
- if (RHSCst->isMaxValue(true))
- return ReplaceInstUsesWith(I, LHS);
- return InsertRangeTest(Val, LHSCst, AddOne(RHSCst),
- true, false, I);
- case ICmpInst::ICMP_UGT: // (X s< 13 | X u> 15) -> no change
- break;
- case ICmpInst::ICMP_NE: // (X s< 13 | X != 15) -> X != 15
- case ICmpInst::ICMP_SLT: // (X s< 13 | X s< 15) -> X s< 15
- return ReplaceInstUsesWith(I, RHS);
- case ICmpInst::ICMP_ULT: // (X s< 13 | X u< 15) -> no change
- break;
- }
- break;
- case ICmpInst::ICMP_UGT:
- switch (RHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X u> 13 | X == 15) -> X u> 13
- case ICmpInst::ICMP_UGT: // (X u> 13 | X u> 15) -> X u> 13
- return ReplaceInstUsesWith(I, LHS);
- case ICmpInst::ICMP_SGT: // (X u> 13 | X s> 15) -> no change
- break;
- case ICmpInst::ICMP_NE: // (X u> 13 | X != 15) -> true
- case ICmpInst::ICMP_ULT: // (X u> 13 | X u< 15) -> true
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
- case ICmpInst::ICMP_SLT: // (X u> 13 | X s< 15) -> no change
- break;
- }
- break;
- case ICmpInst::ICMP_SGT:
- switch (RHSCC) {
- default: llvm_unreachable("Unknown integer condition code!");
- case ICmpInst::ICMP_EQ: // (X s> 13 | X == 15) -> X > 13
- case ICmpInst::ICMP_SGT: // (X s> 13 | X s> 15) -> X > 13
- return ReplaceInstUsesWith(I, LHS);
- case ICmpInst::ICMP_UGT: // (X s> 13 | X u> 15) -> no change
- break;
- case ICmpInst::ICMP_NE: // (X s> 13 | X != 15) -> true
- case ICmpInst::ICMP_SLT: // (X s> 13 | X s< 15) -> true
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
- case ICmpInst::ICMP_ULT: // (X s> 13 | X u< 15) -> no change
- break;
- }
- break;
- }
- return 0;
-}
-
-Instruction *InstCombiner::FoldOrOfFCmps(Instruction &I, FCmpInst *LHS,
- FCmpInst *RHS) {
- if (LHS->getPredicate() == FCmpInst::FCMP_UNO &&
- RHS->getPredicate() == FCmpInst::FCMP_UNO &&
- LHS->getOperand(0)->getType() == RHS->getOperand(0)->getType()) {
- if (ConstantFP *LHSC = dyn_cast<ConstantFP>(LHS->getOperand(1)))
- if (ConstantFP *RHSC = dyn_cast<ConstantFP>(RHS->getOperand(1))) {
- // If either of the constants are nans, then the whole thing returns
- // true.
- if (LHSC->getValueAPF().isNaN() || RHSC->getValueAPF().isNaN())
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
-
- // Otherwise, no need to compare the two constants, compare the
- // rest.
- return new FCmpInst(FCmpInst::FCMP_UNO,
- LHS->getOperand(0), RHS->getOperand(0));
- }
-
- // Handle vector zeros. This occurs because the canonical form of
- // "fcmp uno x,x" is "fcmp uno x, 0".
- if (isa<ConstantAggregateZero>(LHS->getOperand(1)) &&
- isa<ConstantAggregateZero>(RHS->getOperand(1)))
- return new FCmpInst(FCmpInst::FCMP_UNO,
- LHS->getOperand(0), RHS->getOperand(0));
-
- return 0;
- }
-
- Value *Op0LHS = LHS->getOperand(0), *Op0RHS = LHS->getOperand(1);
- Value *Op1LHS = RHS->getOperand(0), *Op1RHS = RHS->getOperand(1);
- FCmpInst::Predicate Op0CC = LHS->getPredicate(), Op1CC = RHS->getPredicate();
-
- if (Op0LHS == Op1RHS && Op0RHS == Op1LHS) {
- // Swap RHS operands to match LHS.
- Op1CC = FCmpInst::getSwappedPredicate(Op1CC);
- std::swap(Op1LHS, Op1RHS);
- }
- if (Op0LHS == Op1LHS && Op0RHS == Op1RHS) {
- // Simplify (fcmp cc0 x, y) | (fcmp cc1 x, y).
- if (Op0CC == Op1CC)
- return new FCmpInst((FCmpInst::Predicate)Op0CC,
- Op0LHS, Op0RHS);
- if (Op0CC == FCmpInst::FCMP_TRUE || Op1CC == FCmpInst::FCMP_TRUE)
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
- if (Op0CC == FCmpInst::FCMP_FALSE)
- return ReplaceInstUsesWith(I, RHS);
- if (Op1CC == FCmpInst::FCMP_FALSE)
- return ReplaceInstUsesWith(I, LHS);
- bool Op0Ordered;
- bool Op1Ordered;
- unsigned Op0Pred = getFCmpCode(Op0CC, Op0Ordered);
- unsigned Op1Pred = getFCmpCode(Op1CC, Op1Ordered);
- if (Op0Ordered == Op1Ordered) {
- // If both are ordered or unordered, return a new fcmp with
- // or'ed predicates.
- Value *RV = getFCmpValue(Op0Ordered, Op0Pred|Op1Pred, Op0LHS, Op0RHS);
- if (Instruction *I = dyn_cast<Instruction>(RV))
- return I;
- // Otherwise, it's a constant boolean value...
- return ReplaceInstUsesWith(I, RV);
- }
- }
- return 0;
-}
-
-/// FoldOrWithConstants - This helper function folds:
-///
-/// ((A | B) & C1) | (B & C2)
-///
-/// into:
-///
-/// (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) {
- ConstantInt *CI1 = dyn_cast<ConstantInt>(C);
- if (!CI1) return 0;
-
- Value *V1 = 0;
- ConstantInt *CI2 = 0;
- if (!match(Op, m_And(m_Value(V1), m_ConstantInt(CI2)))) return 0;
-
- APInt Xor = CI1->getValue() ^ CI2->getValue();
- if (!Xor.isAllOnesValue()) return 0;
-
- if (V1 == A || V1 == B) {
- Value *NewOp = Builder->CreateAnd((V1 == A) ? B : A, CI1);
- return BinaryOperator::CreateOr(NewOp, V1);
- }
-
- return 0;
-}
-
-Instruction *InstCombiner::visitOr(BinaryOperator &I) {
- bool Changed = SimplifyCommutative(I);
- Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-
- if (Value *V = SimplifyOrInst(Op0, Op1, TD))
- return ReplaceInstUsesWith(I, V);
-
-
- // See if we can simplify any instructions used by the instruction whose sole
- // purpose is to compute bits we don't care about.
- if (SimplifyDemandedInstructionBits(I))
- return &I;
-
- if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
- ConstantInt *C1 = 0; Value *X = 0;
- // (X & C1) | C2 --> (X | C2) & (C1|C2)
- if (match(Op0, m_And(m_Value(X), m_ConstantInt(C1))) &&
- Op0->hasOneUse()) {
- Value *Or = Builder->CreateOr(X, RHS);
- Or->takeName(Op0);
- return BinaryOperator::CreateAnd(Or,
- ConstantInt::get(I.getContext(),
- RHS->getValue() | C1->getValue()));
- }
-
- // (X ^ C1) | C2 --> (X | C2) ^ (C1&~C2)
- if (match(Op0, m_Xor(m_Value(X), m_ConstantInt(C1))) &&
- Op0->hasOneUse()) {
- Value *Or = Builder->CreateOr(X, RHS);
- Or->takeName(Op0);
- return BinaryOperator::CreateXor(Or,
- ConstantInt::get(I.getContext(),
- C1->getValue() & ~RHS->getValue()));
- }
-
- // Try to fold constant and into select arguments.
- if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
- if (Instruction *R = FoldOpIntoSelect(I, SI))
- return R;
- if (isa<PHINode>(Op0))
- if (Instruction *NV = FoldOpIntoPhi(I))
- return NV;
- }
-
- Value *A = 0, *B = 0;
- ConstantInt *C1 = 0, *C2 = 0;
-
- // (A | B) | C and A | (B | C) -> bswap if possible.
- // (A >> B) | (C << D) and (A << B) | (B >> C) -> bswap if possible.
- if (match(Op0, m_Or(m_Value(), m_Value())) ||
- match(Op1, m_Or(m_Value(), m_Value())) ||
- (match(Op0, m_Shift(m_Value(), m_Value())) &&
- match(Op1, m_Shift(m_Value(), m_Value())))) {
- if (Instruction *BSwap = MatchBSwap(I))
- return BSwap;
- }
-
- // (X^C)|Y -> (X|Y)^C iff Y&C == 0
- if (Op0->hasOneUse() &&
- match(Op0, m_Xor(m_Value(A), m_ConstantInt(C1))) &&
- MaskedValueIsZero(Op1, C1->getValue())) {
- Value *NOr = Builder->CreateOr(A, Op1);
- NOr->takeName(Op0);
- return BinaryOperator::CreateXor(NOr, C1);
- }
-
- // Y|(X^C) -> (X|Y)^C iff Y&C == 0
- if (Op1->hasOneUse() &&
- match(Op1, m_Xor(m_Value(A), m_ConstantInt(C1))) &&
- MaskedValueIsZero(Op0, C1->getValue())) {
- Value *NOr = Builder->CreateOr(A, Op0);
- NOr->takeName(Op0);
- return BinaryOperator::CreateXor(NOr, C1);
- }
-
- // (A & C)|(B & D)
- Value *C = 0, *D = 0;
- if (match(Op0, m_And(m_Value(A), m_Value(C))) &&
- match(Op1, m_And(m_Value(B), m_Value(D)))) {
- Value *V1 = 0, *V2 = 0, *V3 = 0;
- C1 = dyn_cast<ConstantInt>(C);
- C2 = dyn_cast<ConstantInt>(D);
- if (C1 && C2) { // (A & C1)|(B & C2)
- // If we have: ((V + N) & C1) | (V & C2)
- // .. and C2 = ~C1 and C2 is 0+1+ and (N & C2) == 0
- // replace with V+N.
- if (C1->getValue() == ~C2->getValue()) {
- if ((C2->getValue() & (C2->getValue()+1)) == 0 && // C2 == 0+1+
- match(A, m_Add(m_Value(V1), m_Value(V2)))) {
- // Add commutes, try both ways.
- if (V1 == B && MaskedValueIsZero(V2, C2->getValue()))
- return ReplaceInstUsesWith(I, A);
- if (V2 == B && MaskedValueIsZero(V1, C2->getValue()))
- return ReplaceInstUsesWith(I, A);
- }
- // Or commutes, try both ways.
- if ((C1->getValue() & (C1->getValue()+1)) == 0 &&
- match(B, m_Add(m_Value(V1), m_Value(V2)))) {
- // Add commutes, try both ways.
- if (V1 == A && MaskedValueIsZero(V2, C1->getValue()))
- return ReplaceInstUsesWith(I, B);
- if (V2 == A && MaskedValueIsZero(V1, C1->getValue()))
- return ReplaceInstUsesWith(I, B);
- }
- }
-
- // ((V | N) & C1) | (V & C2) --> (V|N) & (C1|C2)
- // iff (C1&C2) == 0 and (N&~C1) == 0
- if ((C1->getValue() & C2->getValue()) == 0) {
- if (match(A, m_Or(m_Value(V1), m_Value(V2))) &&
- ((V1 == B && MaskedValueIsZero(V2, ~C1->getValue())) || // (V|N)
- (V2 == B && MaskedValueIsZero(V1, ~C1->getValue())))) // (N|V)
- return BinaryOperator::CreateAnd(A,
- ConstantInt::get(A->getContext(),
- C1->getValue()|C2->getValue()));
- // Or commutes, try both ways.
- if (match(B, m_Or(m_Value(V1), m_Value(V2))) &&
- ((V1 == A && MaskedValueIsZero(V2, ~C2->getValue())) || // (V|N)
- (V2 == A && MaskedValueIsZero(V1, ~C2->getValue())))) // (N|V)
- return BinaryOperator::CreateAnd(B,
- ConstantInt::get(B->getContext(),
- C1->getValue()|C2->getValue()));
- }
- }
-
- // Check to see if we have any common things being and'ed. If so, find the
- // terms for V1 & (V2|V3).
- if (Op0->hasOneUse() || Op1->hasOneUse()) {
- V1 = 0;
- if (A == B) // (A & C)|(A & D) == A & (C|D)
- V1 = A, V2 = C, V3 = D;
- else if (A == D) // (A & C)|(B & A) == A & (B|C)
- V1 = A, V2 = B, V3 = C;
- else if (C == B) // (A & C)|(C & D) == C & (A|D)
- V1 = C, V2 = A, V3 = D;
- else if (C == D) // (A & C)|(B & C) == C & (A|B)
- V1 = C, V2 = A, V3 = B;
-
- if (V1) {
- Value *Or = Builder->CreateOr(V2, V3, "tmp");
- return BinaryOperator::CreateAnd(V1, Or);
- }
- }
-
- // (A & (C0?-1:0)) | (B & ~(C0?-1:0)) -> C0 ? A : B, and commuted variants
- if (Instruction *Match = MatchSelectFromAndOr(A, B, C, D))
- return Match;
- if (Instruction *Match = MatchSelectFromAndOr(B, A, D, C))
- return Match;
- if (Instruction *Match = MatchSelectFromAndOr(C, B, A, D))
- return Match;
- if (Instruction *Match = MatchSelectFromAndOr(D, A, B, C))
- return Match;
-
- // ((A&~B)|(~A&B)) -> A^B
- if ((match(C, m_Not(m_Specific(D))) &&
- match(B, m_Not(m_Specific(A)))))
- return BinaryOperator::CreateXor(A, D);
- // ((~B&A)|(~A&B)) -> A^B
- if ((match(A, m_Not(m_Specific(D))) &&
- match(B, m_Not(m_Specific(C)))))
- return BinaryOperator::CreateXor(C, D);
- // ((A&~B)|(B&~A)) -> A^B
- if ((match(C, m_Not(m_Specific(B))) &&
- match(D, m_Not(m_Specific(A)))))
- return BinaryOperator::CreateXor(A, B);
- // ((~B&A)|(B&~A)) -> A^B
- if ((match(A, m_Not(m_Specific(B))) &&
- match(D, m_Not(m_Specific(C)))))
- return BinaryOperator::CreateXor(C, B);
- }
-
- // (X >> Z) | (Y >> Z) -> (X|Y) >> Z for all shifts.
- if (BinaryOperator *SI1 = dyn_cast<BinaryOperator>(Op1)) {
- if (BinaryOperator *SI0 = dyn_cast<BinaryOperator>(Op0))
- if (SI0->isShift() && SI0->getOpcode() == SI1->getOpcode() &&
- SI0->getOperand(1) == SI1->getOperand(1) &&
- (SI0->hasOneUse() || SI1->hasOneUse())) {
- Value *NewOp = Builder->CreateOr(SI0->getOperand(0), SI1->getOperand(0),
- SI0->getName());
- return BinaryOperator::Create(SI1->getOpcode(), NewOp,
- SI1->getOperand(1));
- }
- }
-
- // ((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, 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, Op0, A, B, C);
- if (Ret) return Ret;
- }
-
- // (~A | ~B) == (~(A & B)) - De Morgan's Law
- if (Value *Op0NotVal = dyn_castNotVal(Op0))
- if (Value *Op1NotVal = dyn_castNotVal(Op1))
- if (Op0->hasOneUse() && Op1->hasOneUse()) {
- Value *And = Builder->CreateAnd(Op0NotVal, Op1NotVal,
- I.getName()+".demorgan");
- return BinaryOperator::CreateNot(And);
- }
-
- if (ICmpInst *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
- if (ICmpInst *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
- if (Instruction *Res = FoldOrOfICmps(I, LHS, RHS))
- return Res;
-
- // fold (or (cast A), (cast B)) -> (cast (or A, B))
- if (CastInst *Op0C = dyn_cast<CastInst>(Op0)) {
- if (CastInst *Op1C = dyn_cast<CastInst>(Op1))
- if (Op0C->getOpcode() == Op1C->getOpcode()) {// same cast kind ?
- if (!isa<ICmpInst>(Op0C->getOperand(0)) ||
- !isa<ICmpInst>(Op1C->getOperand(0))) {
- const Type *SrcTy = Op0C->getOperand(0)->getType();
- if (SrcTy == Op1C->getOperand(0)->getType() &&
- SrcTy->isIntOrIntVector() &&
- // Only do this if the casts both really cause code to be
- // generated.
- ValueRequiresCast(Op0C->getOpcode(), Op0C->getOperand(0),
- I.getType()) &&
- ValueRequiresCast(Op1C->getOpcode(), Op1C->getOperand(0),
- I.getType())) {
- Value *NewOp = Builder->CreateOr(Op0C->getOperand(0),
- Op1C->getOperand(0), I.getName());
- return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
- }
- }
- }
- }
-
-
- // (fcmp uno x, c) | (fcmp uno y, c) -> (fcmp uno x, y)
- if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0))) {
- if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1)))
- if (Instruction *Res = FoldOrOfFCmps(I, LHS, RHS))
- return Res;
- }
-
- return Changed ? &I : 0;
-}
-
-Instruction *InstCombiner::visitXor(BinaryOperator &I) {
- bool Changed = SimplifyCommutative(I);
- Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-
- if (isa<UndefValue>(Op1)) {
- if (isa<UndefValue>(Op0))
- // Handle undef ^ undef -> 0 special case. This is a common
- // idiom (misuse).
- return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
- return ReplaceInstUsesWith(I, Op1); // X ^ undef -> undef
- }
-
- // xor X, X = 0
- if (Op0 == Op1)
- return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
-
- // See if we can simplify any instructions used by the instruction whose sole
- // purpose is to compute bits we don't care about.
- if (SimplifyDemandedInstructionBits(I))
- return &I;
- if (isa<VectorType>(I.getType()))
- if (isa<ConstantAggregateZero>(Op1))
- return ReplaceInstUsesWith(I, Op0); // X ^ <0,0> -> X
-
- // Is this a ~ operation?
- if (Value *NotOp = dyn_castNotVal(&I)) {
- if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(NotOp)) {
- if (Op0I->getOpcode() == Instruction::And ||
- Op0I->getOpcode() == Instruction::Or) {
- // ~(~X & Y) --> (X | ~Y) - De Morgan's Law
- // ~(~X | Y) === (X & ~Y) - De Morgan's Law
- if (dyn_castNotVal(Op0I->getOperand(1)))
- Op0I->swapOperands();
- if (Value *Op0NotVal = dyn_castNotVal(Op0I->getOperand(0))) {
- Value *NotY =
- Builder->CreateNot(Op0I->getOperand(1),
- Op0I->getOperand(1)->getName()+".not");
- if (Op0I->getOpcode() == Instruction::And)
- return BinaryOperator::CreateOr(Op0NotVal, NotY);
- return BinaryOperator::CreateAnd(Op0NotVal, NotY);
- }
-
- // ~(X & Y) --> (~X | ~Y) - De Morgan's Law
- // ~(X | Y) === (~X & ~Y) - De Morgan's Law
- if (isFreeToInvert(Op0I->getOperand(0)) &&
- isFreeToInvert(Op0I->getOperand(1))) {
- Value *NotX =
- Builder->CreateNot(Op0I->getOperand(0), "notlhs");
- Value *NotY =
- Builder->CreateNot(Op0I->getOperand(1), "notrhs");
- if (Op0I->getOpcode() == Instruction::And)
- return BinaryOperator::CreateOr(NotX, NotY);
- return BinaryOperator::CreateAnd(NotX, NotY);
- }
- }
- }
- }
-
-
- if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
- if (RHS->isOne() && 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));
-
- if (FCmpInst *FCI = dyn_cast<FCmpInst>(Op0))
- return new FCmpInst(FCI->getInversePredicate(),
- FCI->getOperand(0), FCI->getOperand(1));
- }
-
- // fold (xor(zext(cmp)), 1) and (xor(sext(cmp)), -1) to ext(!cmp).
- if (CastInst *Op0C = dyn_cast<CastInst>(Op0)) {
- if (CmpInst *CI = dyn_cast<CmpInst>(Op0C->getOperand(0))) {
- if (CI->hasOneUse() && Op0C->hasOneUse()) {
- Instruction::CastOps Opcode = Op0C->getOpcode();
- if ((Opcode == Instruction::ZExt || Opcode == Instruction::SExt) &&
- (RHS == ConstantExpr::getCast(Opcode,
- ConstantInt::getTrue(I.getContext()),
- Op0C->getDestTy()))) {
- CI->setPredicate(CI->getInversePredicate());
- return CastInst::Create(Opcode, CI, Op0C->getType());
- }
- }
- }
- }
-
- if (BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0)) {
- // ~(c-X) == X-c-1 == X+(-c-1)
- if (Op0I->getOpcode() == Instruction::Sub && RHS->isAllOnesValue())
- if (Constant *Op0I0C = dyn_cast<Constant>(Op0I->getOperand(0))) {
- Constant *NegOp0I0C = ConstantExpr::getNeg(Op0I0C);
- Constant *ConstantRHS = ConstantExpr::getSub(NegOp0I0C,
- ConstantInt::get(I.getType(), 1));
- return BinaryOperator::CreateAdd(Op0I->getOperand(1), ConstantRHS);
- }
-
- if (ConstantInt *Op0CI = dyn_cast<ConstantInt>(Op0I->getOperand(1))) {
- if (Op0I->getOpcode() == Instruction::Add) {
- // ~(X-c) --> (-c-1)-X
- if (RHS->isAllOnesValue()) {
- Constant *NegOp0CI = ConstantExpr::getNeg(Op0CI);
- return BinaryOperator::CreateSub(
- ConstantExpr::getSub(NegOp0CI,
- ConstantInt::get(I.getType(), 1)),
- Op0I->getOperand(0));
- } else if (RHS->getValue().isSignBit()) {
- // (X + C) ^ signbit -> (X + C + signbit)
- Constant *C = ConstantInt::get(I.getContext(),
- RHS->getValue() + Op0CI->getValue());
- return BinaryOperator::CreateAdd(Op0I->getOperand(0), C);
-
- }
- } else if (Op0I->getOpcode() == Instruction::Or) {
- // (X|C1)^C2 -> X^(C1|C2) iff X&~C1 == 0
- if (MaskedValueIsZero(Op0I->getOperand(0), Op0CI->getValue())) {
- Constant *NewRHS = ConstantExpr::getOr(Op0CI, RHS);
- // Anything in both C1 and C2 is known to be zero, remove it from
- // NewRHS.
- Constant *CommonBits = ConstantExpr::getAnd(Op0CI, RHS);
- NewRHS = ConstantExpr::getAnd(NewRHS,
- ConstantExpr::getNot(CommonBits));
- Worklist.Add(Op0I);
- I.setOperand(0, Op0I->getOperand(0));
- I.setOperand(1, NewRHS);
- return &I;
- }
- }
- }
- }
-
- // Try to fold constant and into select arguments.
- if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
- if (Instruction *R = FoldOpIntoSelect(I, SI))
- return R;
- if (isa<PHINode>(Op0))
- if (Instruction *NV = FoldOpIntoPhi(I))
- return NV;
- }
-
- if (Value *X = dyn_castNotVal(Op0)) // ~A ^ A == -1
- if (X == Op1)
- return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
-
- if (Value *X = dyn_castNotVal(Op1)) // A ^ ~A == -1
- if (X == Op0)
- return ReplaceInstUsesWith(I, Constant::getAllOnesValue(I.getType()));
-
-
- BinaryOperator *Op1I = dyn_cast<BinaryOperator>(Op1);
- if (Op1I) {
- Value *A, *B;
- if (match(Op1I, m_Or(m_Value(A), m_Value(B)))) {
- if (A == Op0) { // B^(B|A) == (A|B)^B
- Op1I->swapOperands();
- I.swapOperands();
- std::swap(Op0, Op1);
- } else if (B == Op0) { // B^(A|B) == (A|B)^B
- I.swapOperands(); // Simplified below.
- std::swap(Op0, Op1);
- }
- } else if (match(Op1I, m_Xor(m_Specific(Op0), m_Value(B)))) {
- return ReplaceInstUsesWith(I, B); // A^(A^B) == B
- } else if (match(Op1I, m_Xor(m_Value(A), m_Specific(Op0)))) {
- return ReplaceInstUsesWith(I, A); // A^(B^A) == B
- } else if (match(Op1I, m_And(m_Value(A), m_Value(B))) &&
- Op1I->hasOneUse()){
- if (A == Op0) { // A^(A&B) -> A^(B&A)
- Op1I->swapOperands();
- std::swap(A, B);
- }
- if (B == Op0) { // A^(B&A) -> (B&A)^A
- I.swapOperands(); // Simplified below.
- std::swap(Op0, Op1);
- }
- }
- }
-
- BinaryOperator *Op0I = dyn_cast<BinaryOperator>(Op0);
- if (Op0I) {
- Value *A, *B;
- if (match(Op0I, m_Or(m_Value(A), m_Value(B))) &&
- Op0I->hasOneUse()) {
- if (A == Op1) // (B|A)^B == (A|B)^B
- std::swap(A, B);
- if (B == Op1) // (A|B)^B == A & ~B
- return BinaryOperator::CreateAnd(A, Builder->CreateNot(Op1, "tmp"));
- } else if (match(Op0I, m_Xor(m_Specific(Op1), m_Value(B)))) {
- return ReplaceInstUsesWith(I, B); // (A^B)^A == B
- } else if (match(Op0I, m_Xor(m_Value(A), m_Specific(Op1)))) {
- return ReplaceInstUsesWith(I, A); // (B^A)^A == B
- } else if (match(Op0I, m_And(m_Value(A), m_Value(B))) &&
- Op0I->hasOneUse()){
- if (A == Op1) // (A&B)^A -> (B&A)^A
- std::swap(A, B);
- if (B == Op1 && // (B&A)^A == ~B & A
- !isa<ConstantInt>(Op1)) { // Canonical form is (B&C)^C
- return BinaryOperator::CreateAnd(Builder->CreateNot(A, "tmp"), Op1);
- }
- }
- }
-
- // (X >> Z) ^ (Y >> Z) -> (X^Y) >> Z for all shifts.
- if (Op0I && Op1I && Op0I->isShift() &&
- Op0I->getOpcode() == Op1I->getOpcode() &&
- Op0I->getOperand(1) == Op1I->getOperand(1) &&
- (Op1I->hasOneUse() || Op1I->hasOneUse())) {
- Value *NewOp =
- Builder->CreateXor(Op0I->getOperand(0), Op1I->getOperand(0),
- Op0I->getName());
- return BinaryOperator::Create(Op1I->getOpcode(), NewOp,
- Op1I->getOperand(1));
- }
-
- if (Op0I && Op1I) {
- Value *A, *B, *C, *D;
- // (A & B)^(A | B) -> A ^ B
- if (match(Op0I, m_And(m_Value(A), m_Value(B))) &&
- match(Op1I, m_Or(m_Value(C), m_Value(D)))) {
- if ((A == C && B == D) || (A == D && B == C))
- return BinaryOperator::CreateXor(A, B);
- }
- // (A | B)^(A & B) -> A ^ B
- if (match(Op0I, m_Or(m_Value(A), m_Value(B))) &&
- match(Op1I, m_And(m_Value(C), m_Value(D)))) {
- if ((A == C && B == D) || (A == D && B == C))
- return BinaryOperator::CreateXor(A, B);
- }
-
- // (A & B)^(C & D)
- if ((Op0I->hasOneUse() || Op1I->hasOneUse()) &&
- match(Op0I, m_And(m_Value(A), m_Value(B))) &&
- match(Op1I, m_And(m_Value(C), m_Value(D)))) {
- // (X & Y)^(X & Y) -> (Y^Z) & X
- Value *X = 0, *Y = 0, *Z = 0;
- if (A == C)
- X = A, Y = B, Z = D;
- else if (A == D)
- X = A, Y = B, Z = C;
- else if (B == C)
- X = B, Y = A, Z = D;
- else if (B == D)
- X = B, Y = A, Z = C;
-
- if (X) {
- Value *NewOp = Builder->CreateXor(Y, Z, Op0->getName());
- return BinaryOperator::CreateAnd(NewOp, X);
- }
- }
- }
-
- // (icmp1 A, B) ^ (icmp2 A, B) --> (icmp3 A, B)
- if (ICmpInst *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
- if (ICmpInst *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
- if (PredicatesFoldable(LHS->getPredicate(), RHS->getPredicate())) {
- if (LHS->getOperand(0) == RHS->getOperand(1) &&
- LHS->getOperand(1) == RHS->getOperand(0))
- LHS->swapOperands();
- if (LHS->getOperand(0) == RHS->getOperand(0) &&
- LHS->getOperand(1) == RHS->getOperand(1)) {
- Value *Op0 = LHS->getOperand(0), *Op1 = LHS->getOperand(1);
- unsigned Code = getICmpCode(LHS) ^ getICmpCode(RHS);
- bool isSigned = LHS->isSigned() || RHS->isSigned();
- Value *RV = getICmpValue(isSigned, Code, Op0, Op1);
- if (Instruction *I = dyn_cast<Instruction>(RV))
- return I;
- // Otherwise, it's a constant boolean value.
- return ReplaceInstUsesWith(I, RV);
- }
- }
-
- // fold (xor (cast A), (cast B)) -> (cast (xor A, B))
- if (CastInst *Op0C = dyn_cast<CastInst>(Op0)) {
- if (CastInst *Op1C = dyn_cast<CastInst>(Op1))
- if (Op0C->getOpcode() == Op1C->getOpcode()) { // same cast kind?
- const Type *SrcTy = Op0C->getOperand(0)->getType();
- if (SrcTy == Op1C->getOperand(0)->getType() && SrcTy->isInteger() &&
- // Only do this if the casts both really cause code to be generated.
- ValueRequiresCast(Op0C->getOpcode(), Op0C->getOperand(0),
- I.getType()) &&
- ValueRequiresCast(Op1C->getOpcode(), Op1C->getOperand(0),
- I.getType())) {
- Value *NewOp = Builder->CreateXor(Op0C->getOperand(0),
- Op1C->getOperand(0), I.getName());
- return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
- }
- }
- }
-
- return Changed ? &I : 0;
-}
-
-
-Instruction *InstCombiner::visitShl(BinaryOperator &I) {
- return commonShiftTransforms(I);
-}
-
-Instruction *InstCombiner::visitLShr(BinaryOperator &I) {
- return commonShiftTransforms(I);
-}
-
-Instruction *InstCombiner::visitAShr(BinaryOperator &I) {
- if (Instruction *R = commonShiftTransforms(I))
- return R;
-
- Value *Op0 = I.getOperand(0);
-
- // ashr int -1, X = -1 (for any arithmetic shift rights of ~0)
- if (ConstantInt *CSI = dyn_cast<ConstantInt>(Op0))
- if (CSI->isAllOnesValue())
- return ReplaceInstUsesWith(I, CSI);
-
- // See if we can turn a signed shr into an unsigned shr.
- if (MaskedValueIsZero(Op0,
- APInt::getSignBit(I.getType()->getScalarSizeInBits())))
- 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()->getScalarSizeInBits())
- return ReplaceInstUsesWith(I, Op0);
-
- return 0;
-}
-
-Instruction *InstCombiner::commonShiftTransforms(BinaryOperator &I) {
- assert(I.getOperand(1)->getType() == I.getOperand(0)->getType());
- Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
-
- // shl X, 0 == X and shr X, 0 == X
- // shl 0, X == 0 and shr 0, X == 0
- if (Op1 == Constant::getNullValue(Op1->getType()) ||
- Op0 == Constant::getNullValue(Op0->getType()))
- return ReplaceInstUsesWith(I, Op0);
-
- if (isa<UndefValue>(Op0)) {
- if (I.getOpcode() == Instruction::AShr) // undef >>s X -> undef
- return ReplaceInstUsesWith(I, Op0);
- else // undef << X -> 0, undef >>u X -> 0
- return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
- }
- if (isa<UndefValue>(Op1)) {
- if (I.getOpcode() == Instruction::AShr) // X >>s undef -> X
- return ReplaceInstUsesWith(I, Op0);
- else // X << undef, X >>u undef -> 0
- return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
- }
-
- // See if we can fold away this shift.
- if (SimplifyDemandedInstructionBits(I))
- return &I;
-
- // Try to fold constant and into select arguments.
- if (isa<Constant>(Op0))
- if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
- if (Instruction *R = FoldOpIntoSelect(I, SI))
- return R;
-
- if (ConstantInt *CUI = dyn_cast<ConstantInt>(Op1))
- if (Instruction *Res = FoldShiftByConstant(Op0, CUI, I))
- return Res;
- return 0;
-}
-
-Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
- BinaryOperator &I) {
- 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()->getScalarSizeInBits();
-
- // shl i32 X, 32 = 0 and srl i8 Y, 9 = 0, ... just don't eliminate
- // a signed shift.
- //
- if (Op1->uge(TypeBits)) {
- if (I.getOpcode() != Instruction::AShr)
- return ReplaceInstUsesWith(I, Constant::getNullValue(Op0->getType()));
- else {
- I.setOperand(1, ConstantInt::get(I.getType(), TypeBits-1));
- return &I;
- }
- }
-
- // ((X*C1) << C2) == (X * (C1 << C2))
- if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Op0))
- if (BO->getOpcode() == Instruction::Mul && isLeftShift)
- if (Constant *BOOp = dyn_cast<Constant>(BO->getOperand(1)))
- return BinaryOperator::CreateMul(BO->getOperand(0),
- ConstantExpr::getShl(BOOp, Op1));
-
- // Try to fold constant and into select arguments.
- if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
- if (Instruction *R = FoldOpIntoSelect(I, SI))
- return R;
- if (isa<PHINode>(Op0))
- if (Instruction *NV = FoldOpIntoPhi(I))
- return NV;
-
- // Fold shift2(trunc(shift1(x,c1)), c2) -> trunc(shift2(shift1(x,c1),c2))
- if (TruncInst *TI = dyn_cast<TruncInst>(Op0)) {
- Instruction *TrOp = dyn_cast<Instruction>(TI->getOperand(0));
- // If 'shift2' is an ashr, we would have to get the sign bit into a funny
- // place. Don't try to do this transformation in this case. Also, we
- // require that the input operand is a shift-by-constant so that we have
- // confidence that the shifts will get folded together. We could do this
- // xform in more cases, but it is unlikely to be profitable.
- if (TrOp && I.isLogicalShift() && TrOp->isShift() &&
- isa<ConstantInt>(TrOp->getOperand(1))) {
- // Okay, we'll do this xform. Make the shift of shift.
- Constant *ShAmt = ConstantExpr::getZExt(Op1, TrOp->getType());
- // (shift2 (shift1 & 0x00FF), c2)
- Value *NSh = Builder->CreateBinOp(I.getOpcode(), TrOp, ShAmt,I.getName());
-
- // For logical shifts, the truncation has the effect of making the high
- // part of the register be zeros. Emulate this by inserting an AND to
- // clear the top bits as needed. This 'and' will usually be zapped by
- // other xforms later if dead.
- unsigned SrcSize = TrOp->getType()->getScalarSizeInBits();
- unsigned DstSize = TI->getType()->getScalarSizeInBits();
- APInt MaskV(APInt::getLowBitsSet(SrcSize, DstSize));
-
- // The mask we constructed says what the trunc would do if occurring
- // between the shifts. We want to know the effect *after* the second
- // shift. We know that it is a logical shift by a constant, so adjust the
- // mask as appropriate.
- if (I.getOpcode() == Instruction::Shl)
- MaskV <<= Op1->getZExtValue();
- else {
- assert(I.getOpcode() == Instruction::LShr && "Unknown logical shift");
- MaskV = MaskV.lshr(Op1->getZExtValue());
- }
-
- // shift1 & 0x00FF
- Value *And = Builder->CreateAnd(NSh,
- ConstantInt::get(I.getContext(), MaskV),
- TI->getName());
-
- // Return the value truncated to the interesting size.
- return new TruncInst(And, I.getType());
- }
- }
-
- if (Op0->hasOneUse()) {
- if (BinaryOperator *Op0BO = dyn_cast<BinaryOperator>(Op0)) {
- // Turn ((X >> C) + Y) << C -> (X + (Y << C)) & (~0 << C)
- Value *V1, *V2;
- ConstantInt *CC;
- switch (Op0BO->getOpcode()) {
- default: break;
- case Instruction::Add:
- case Instruction::And:
- case Instruction::Or:
- case Instruction::Xor: {
- // These operators commute.
- // Turn (Y + (X >> C)) << C -> (X + (Y << C)) & (~0 << C)
- if (isLeftShift && Op0BO->getOperand(1)->hasOneUse() &&
- match(Op0BO->getOperand(1), m_Shr(m_Value(V1),
- m_Specific(Op1)))) {
- Value *YS = // (Y << C)
- Builder->CreateShl(Op0BO->getOperand(0), Op1, Op0BO->getName());
- // (X + (Y << C))
- Value *X = Builder->CreateBinOp(Op0BO->getOpcode(), YS, V1,
- Op0BO->getOperand(1)->getName());
- uint32_t Op1Val = Op1->getLimitedValue(TypeBits);
- return BinaryOperator::CreateAnd(X, ConstantInt::get(I.getContext(),
- APInt::getHighBitsSet(TypeBits, TypeBits-Op1Val)));
- }
-
- // Turn (Y + ((X >> C) & CC)) << C -> ((X & (CC << C)) + (Y << C))
- Value *Op0BOOp1 = Op0BO->getOperand(1);
- if (isLeftShift && Op0BOOp1->hasOneUse() &&
- match(Op0BOOp1,
- m_And(m_Shr(m_Value(V1), m_Specific(Op1)),
- m_ConstantInt(CC))) &&
- cast<BinaryOperator>(Op0BOOp1)->getOperand(0)->hasOneUse()) {
- Value *YS = // (Y << C)
- Builder->CreateShl(Op0BO->getOperand(0), Op1,
- Op0BO->getName());
- // X & (CC << C)
- Value *XM = Builder->CreateAnd(V1, ConstantExpr::getShl(CC, Op1),
- V1->getName()+".mask");
- return BinaryOperator::Create(Op0BO->getOpcode(), YS, XM);
- }
- }
-
- // FALL THROUGH.
- case Instruction::Sub: {
- // Turn ((X >> C) + Y) << C -> (X + (Y << C)) & (~0 << C)
- if (isLeftShift && Op0BO->getOperand(0)->hasOneUse() &&
- match(Op0BO->getOperand(0), m_Shr(m_Value(V1),
- m_Specific(Op1)))) {
- Value *YS = // (Y << C)
- Builder->CreateShl(Op0BO->getOperand(1), Op1, Op0BO->getName());
- // (X + (Y << C))
- Value *X = Builder->CreateBinOp(Op0BO->getOpcode(), V1, YS,
- Op0BO->getOperand(0)->getName());
- uint32_t Op1Val = Op1->getLimitedValue(TypeBits);
- return BinaryOperator::CreateAnd(X, ConstantInt::get(I.getContext(),
- APInt::getHighBitsSet(TypeBits, TypeBits-Op1Val)));
- }
-
- // Turn (((X >> C)&CC) + Y) << C -> (X + (Y << C)) & (CC << C)
- if (isLeftShift && Op0BO->getOperand(0)->hasOneUse() &&
- match(Op0BO->getOperand(0),
- m_And(m_Shr(m_Value(V1), m_Value(V2)),
- m_ConstantInt(CC))) && V2 == Op1 &&
- cast<BinaryOperator>(Op0BO->getOperand(0))
- ->getOperand(0)->hasOneUse()) {
- Value *YS = // (Y << C)
- Builder->CreateShl(Op0BO->getOperand(1), Op1, Op0BO->getName());
- // X & (CC << C)
- Value *XM = Builder->CreateAnd(V1, ConstantExpr::getShl(CC, Op1),
- V1->getName()+".mask");
-
- return BinaryOperator::Create(Op0BO->getOpcode(), XM, YS);
- }
-
- break;
- }
- }
-
-
- // If the operand is an bitwise operator with a constant RHS, and the
- // shift is the only use, we can pull it out of the shift.
- if (ConstantInt *Op0C = dyn_cast<ConstantInt>(Op0BO->getOperand(1))) {
- bool isValid = true; // Valid only for And, Or, Xor
- bool highBitSet = false; // Transform if high bit of constant set?
-
- switch (Op0BO->getOpcode()) {
- default: isValid = false; break; // Do not perform transform!
- case Instruction::Add:
- isValid = isLeftShift;
- break;
- case Instruction::Or:
- case Instruction::Xor:
- highBitSet = false;
- break;
- case Instruction::And:
- highBitSet = true;
- break;
- }
-
- // If this is a signed shift right, and the high bit is modified
- // by the logical operation, do not perform the transformation.
- // The highBitSet boolean indicates the value of the high bit of
- // the constant which would cause it to be modified for this
- // operation.
- //
- if (isValid && I.getOpcode() == Instruction::AShr)
- isValid = Op0C->getValue()[TypeBits-1] == highBitSet;
-
- if (isValid) {
- Constant *NewRHS = ConstantExpr::get(I.getOpcode(), Op0C, Op1);
-
- Value *NewShift =
- Builder->CreateBinOp(I.getOpcode(), Op0BO->getOperand(0), Op1);
- NewShift->takeName(Op0BO);
-
- return BinaryOperator::Create(Op0BO->getOpcode(), NewShift,
- NewRHS);
- }
- }
- }
- }
-
- // Find out if this is a shift of a shift by a constant.
- BinaryOperator *ShiftOp = dyn_cast<BinaryOperator>(Op0);
- if (ShiftOp && !ShiftOp->isShift())
- ShiftOp = 0;
-
- if (ShiftOp && isa<ConstantInt>(ShiftOp->getOperand(1))) {
- ConstantInt *ShiftAmt1C = cast<ConstantInt>(ShiftOp->getOperand(1));
- uint32_t ShiftAmt1 = ShiftAmt1C->getLimitedValue(TypeBits);
- uint32_t ShiftAmt2 = Op1->getLimitedValue(TypeBits);
- assert(ShiftAmt2 != 0 && "Should have been simplified earlier");
- if (ShiftAmt1 == 0) return 0; // Will be simplified in the future.
- Value *X = ShiftOp->getOperand(0);
-
- uint32_t AmtSum = ShiftAmt1+ShiftAmt2; // Fold into one big shift.
-
- const IntegerType *Ty = cast<IntegerType>(I.getType());
-
- // Check for (X << c1) << c2 and (X >> c1) >> c2
- if (I.getOpcode() == ShiftOp->getOpcode()) {
- // If this is oversized composite shift, then unsigned shifts get 0, ashr
- // saturates.
- if (AmtSum >= TypeBits) {
- if (I.getOpcode() != Instruction::AShr)
- return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
- AmtSum = TypeBits-1; // Saturate to 31 for i32 ashr.
- }
-
- return BinaryOperator::Create(I.getOpcode(), X,
- ConstantInt::get(Ty, AmtSum));
- }
-
- if (ShiftOp->getOpcode() == Instruction::LShr &&
- I.getOpcode() == Instruction::AShr) {
- if (AmtSum >= TypeBits)
- return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
-
- // ((X >>u C1) >>s C2) -> (X >>u (C1+C2)) since C1 != 0.
- return BinaryOperator::CreateLShr(X, ConstantInt::get(Ty, AmtSum));
- }
-
- if (ShiftOp->getOpcode() == Instruction::AShr &&
- I.getOpcode() == Instruction::LShr) {
- // ((X >>s C1) >>u C2) -> ((X >>s (C1+C2)) & mask) since C1 != 0.
- if (AmtSum >= TypeBits)
- AmtSum = TypeBits-1;
-
- Value *Shift = Builder->CreateAShr(X, ConstantInt::get(Ty, AmtSum));
-
- APInt Mask(APInt::getLowBitsSet(TypeBits, TypeBits - ShiftAmt2));
- return BinaryOperator::CreateAnd(Shift,
- ConstantInt::get(I.getContext(), Mask));
- }
-
- // Okay, if we get here, one shift must be left, and the other shift must be
- // right. See if the amounts are equal.
- if (ShiftAmt1 == ShiftAmt2) {
- // If we have ((X >>? C) << C), turn this into X & (-1 << C).
- if (I.getOpcode() == Instruction::Shl) {
- APInt Mask(APInt::getHighBitsSet(TypeBits, TypeBits - ShiftAmt1));
- return BinaryOperator::CreateAnd(X,
- ConstantInt::get(I.getContext(),Mask));
- }
- // If we have ((X << C) >>u C), turn this into X & (-1 >>u C).
- if (I.getOpcode() == Instruction::LShr) {
- APInt Mask(APInt::getLowBitsSet(TypeBits, TypeBits - ShiftAmt1));
- return BinaryOperator::CreateAnd(X,
- ConstantInt::get(I.getContext(), Mask));
- }
- // We can simplify ((X << C) >>s C) into a trunc + sext.
- // NOTE: we could do this for any C, but that would make 'unusual' integer
- // types. For now, just stick to ones well-supported by the code
- // generators.
- const Type *SExtType = 0;
- switch (Ty->getBitWidth() - ShiftAmt1) {
- case 1 :
- case 8 :
- case 16 :
- case 32 :
- case 64 :
- case 128:
- SExtType = IntegerType::get(I.getContext(),
- Ty->getBitWidth() - ShiftAmt1);
- break;
- default: break;
- }
- if (SExtType)
- return new SExtInst(Builder->CreateTrunc(X, SExtType, "sext"), Ty);
- // Otherwise, we can't handle it yet.
- } else if (ShiftAmt1 < ShiftAmt2) {
- uint32_t ShiftDiff = ShiftAmt2-ShiftAmt1;
-
- // (X >>? C1) << C2 --> X << (C2-C1) & (-1 << C2)
- if (I.getOpcode() == Instruction::Shl) {
- assert(ShiftOp->getOpcode() == Instruction::LShr ||
- ShiftOp->getOpcode() == Instruction::AShr);
- Value *Shift = Builder->CreateShl(X, ConstantInt::get(Ty, ShiftDiff));
-
- APInt Mask(APInt::getHighBitsSet(TypeBits, TypeBits - ShiftAmt2));
- return BinaryOperator::CreateAnd(Shift,
- ConstantInt::get(I.getContext(),Mask));
- }
-
- // (X << C1) >>u C2 --> X >>u (C2-C1) & (-1 >> C2)
- if (I.getOpcode() == Instruction::LShr) {
- assert(ShiftOp->getOpcode() == Instruction::Shl);
- Value *Shift = Builder->CreateLShr(X, ConstantInt::get(Ty, ShiftDiff));
-
- APInt Mask(APInt::getLowBitsSet(TypeBits, TypeBits - ShiftAmt2));
- return BinaryOperator::CreateAnd(Shift,
- ConstantInt::get(I.getContext(),Mask));
- }
-
- // We can't handle (X << C1) >>s C2, it shifts arbitrary bits in.
- } else {
- assert(ShiftAmt2 < ShiftAmt1);
- uint32_t ShiftDiff = ShiftAmt1-ShiftAmt2;
-
- // (X >>? C1) << C2 --> X >>? (C1-C2) & (-1 << C2)
- if (I.getOpcode() == Instruction::Shl) {
- assert(ShiftOp->getOpcode() == Instruction::LShr ||
- ShiftOp->getOpcode() == Instruction::AShr);
- Value *Shift = Builder->CreateBinOp(ShiftOp->getOpcode(), X,
- ConstantInt::get(Ty, ShiftDiff));
-
- APInt Mask(APInt::getHighBitsSet(TypeBits, TypeBits - ShiftAmt2));
- return BinaryOperator::CreateAnd(Shift,
- ConstantInt::get(I.getContext(),Mask));
- }
-
- // (X << C1) >>u C2 --> X << (C1-C2) & (-1 >> C2)
- if (I.getOpcode() == Instruction::LShr) {
- assert(ShiftOp->getOpcode() == Instruction::Shl);
- Value *Shift = Builder->CreateShl(X, ConstantInt::get(Ty, ShiftDiff));
-
- APInt Mask(APInt::getLowBitsSet(TypeBits, TypeBits - ShiftAmt2));
- return BinaryOperator::CreateAnd(Shift,
- ConstantInt::get(I.getContext(),Mask));
- }
-
- // We can't handle (X << C1) >>a C2, it shifts arbitrary bits in.
- }
- }
- 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.
-const Type *InstCombiner::FindElementAtOffset(const Type *Ty, int64_t Offset,
- SmallVectorImpl<Value*> &NewIndices) {
- if (!TD) return 0;
- 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(Ty->getContext());
- int64_t FirstIdx = 0;
- if (int64_t TySize = TD->getTypeAllocSize(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::getInt32Ty(Ty->getContext()),
- Elt));
-
- Offset -= SL->getElementOffset(Elt);
- Ty = STy->getElementType(Elt);
- } else if (const ArrayType *AT = dyn_cast<ArrayType>(Ty)) {
- uint64_t EltSize = TD->getTypeAllocSize(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;
-}
-
-
-/// EnforceKnownAlignment - If the specified pointer points to an object that
-/// we control, modify the object's alignment to PrefAlign. This isn't
-/// often possible though. If alignment is important, a more reliable approach
-/// is to simply align all global variables and allocation instructions to
-/// their preferred alignment from the beginning.
-///
-static unsigned EnforceKnownAlignment(Value *V,
- unsigned Align, unsigned PrefAlign) {
-
- User *U = dyn_cast<User>(V);
- if (!U) return Align;
-
- switch (Operator::getOpcode(U)) {
- default: break;
- case Instruction::BitCast:
- return EnforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
- case Instruction::GetElementPtr: {
- // If all indexes are zero, it is just the alignment of the base pointer.
- bool AllZeroOperands = true;
- for (User::op_iterator i = U->op_begin() + 1, e = U->op_end(); i != e; ++i)
- if (!isa<Constant>(*i) ||
- !cast<Constant>(*i)->isNullValue()) {
- AllZeroOperands = false;
- break;
- }
-
- if (AllZeroOperands) {
- // Treat this like a bitcast.
- return EnforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
- }
- break;
- }
- }
-
- if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
- // If there is a large requested alignment and we can, bump up the alignment
- // of the global.
- if (!GV->isDeclaration()) {
- if (GV->getAlignment() >= PrefAlign)
- Align = GV->getAlignment();
- else {
- GV->setAlignment(PrefAlign);
- Align = PrefAlign;
- }
- }
- } else if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
- // If there is a requested alignment and if this is an alloca, round up.
- if (AI->getAlignment() >= PrefAlign)
- Align = AI->getAlignment();
- else {
- AI->setAlignment(PrefAlign);
- Align = PrefAlign;
- }
- }
-
- return Align;
-}
-
-/// GetOrEnforceKnownAlignment - If the specified pointer has an alignment that
-/// we can determine, return it, otherwise return 0. If PrefAlign is specified,
-/// and it is more than the alignment of the ultimate object, see if we can
-/// increase the alignment of the ultimate object, making this check succeed.
-unsigned InstCombiner::GetOrEnforceKnownAlignment(Value *V,
- unsigned PrefAlign) {
- unsigned BitWidth = TD ? TD->getTypeSizeInBits(V->getType()) :
- sizeof(PrefAlign) * CHAR_BIT;
- APInt Mask = APInt::getAllOnesValue(BitWidth);
- APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- ComputeMaskedBits(V, Mask, KnownZero, KnownOne);
- unsigned TrailZ = KnownZero.countTrailingOnes();
- unsigned Align = 1u << std::min(BitWidth - 1, TrailZ);
-
- if (PrefAlign > Align)
- Align = EnforceKnownAlignment(V, Align, PrefAlign);
-
- // We don't need to make any adjustment.
- return Align;
-}
-
-Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) {
- unsigned DstAlign = GetOrEnforceKnownAlignment(MI->getOperand(1));
- unsigned SrcAlign = GetOrEnforceKnownAlignment(MI->getOperand(2));
- unsigned MinAlign = std::min(DstAlign, SrcAlign);
- unsigned CopyAlign = MI->getAlignment();
-
- if (CopyAlign < MinAlign) {
- MI->setAlignment(ConstantInt::get(MI->getAlignmentType(),
- MinAlign, false));
- return MI;
- }
-
- // If MemCpyInst length is 1/2/4/8 bytes then replace memcpy with
- // load/store.
- ConstantInt *MemOpLength = dyn_cast<ConstantInt>(MI->getOperand(3));
- if (MemOpLength == 0) return 0;
-
- // Source and destination pointer types are always "i8*" for intrinsic. See
- // if the size is something we can handle with a single primitive load/store.
- // A single load+store correctly handles overlapping memory in the memmove
- // case.
- unsigned Size = MemOpLength->getZExtValue();
- if (Size == 0) return MI; // Delete this mem transfer.
-
- if (Size > 8 || (Size&(Size-1)))
- return 0; // If not 1/2/4/8 bytes, exit.
-
- // Use an integer load+store unless we can find something better.
- Type *NewPtrTy =
- PointerType::getUnqual(IntegerType::get(MI->getContext(), Size<<3));
-
- // Memcpy forces the use of i8* for the source and destination. That means
- // that if you're using memcpy to move one double around, you'll get a cast
- // from double* to i8*. We'd much rather use a double load+store rather than
- // an i64 load+store, here because this improves the odds that the source or
- // dest address will be promotable. See if we can find a better type than the
- // integer datatype.
- if (Value *Op = getBitCastOperand(MI->getOperand(1))) {
- const Type *SrcETy = cast<PointerType>(Op->getType())->getElementType();
- if (TD && SrcETy->isSized() && TD->getTypeStoreSize(SrcETy) == Size) {
- // The SrcETy might be something like {{{double}}} or [1 x double]. Rip
- // down through these levels if so.
- while (!SrcETy->isSingleValueType()) {
- if (const StructType *STy = dyn_cast<StructType>(SrcETy)) {
- if (STy->getNumElements() == 1)
- SrcETy = STy->getElementType(0);
- else
- break;
- } else if (const ArrayType *ATy = dyn_cast<ArrayType>(SrcETy)) {
- if (ATy->getNumElements() == 1)
- SrcETy = ATy->getElementType();
- else
- break;
- } else
- break;
- }
-
- if (SrcETy->isSingleValueType())
- NewPtrTy = PointerType::getUnqual(SrcETy);
- }
- }
-
-
- // If the memcpy/memmove provides better alignment info than we can
- // infer, use it.
- SrcAlign = std::max(SrcAlign, CopyAlign);
- DstAlign = std::max(DstAlign, CopyAlign);
-
- Value *Src = Builder->CreateBitCast(MI->getOperand(2), NewPtrTy);
- Value *Dest = Builder->CreateBitCast(MI->getOperand(1), NewPtrTy);
- Instruction *L = new LoadInst(Src, "tmp", false, SrcAlign);
- InsertNewInstBefore(L, *MI);
- InsertNewInstBefore(new StoreInst(L, Dest, false, DstAlign), *MI);
-
- // Set the size of the copy to 0, it will be deleted on the next iteration.
- MI->setOperand(3, Constant::getNullValue(MemOpLength->getType()));
- return MI;
-}
-
-Instruction *InstCombiner::SimplifyMemSet(MemSetInst *MI) {
- unsigned Alignment = GetOrEnforceKnownAlignment(MI->getDest());
- if (MI->getAlignment() < Alignment) {
- MI->setAlignment(ConstantInt::get(MI->getAlignmentType(),
- Alignment, false));
- return MI;
- }
-
- // Extract the length and alignment and fill if they are constant.
- ConstantInt *LenC = dyn_cast<ConstantInt>(MI->getLength());
- ConstantInt *FillC = dyn_cast<ConstantInt>(MI->getValue());
- if (!LenC || !FillC || FillC->getType() != Type::getInt8Ty(MI->getContext()))
- return 0;
- uint64_t Len = LenC->getZExtValue();
- Alignment = MI->getAlignment();
-
- // If the length is zero, this is a no-op
- if (Len == 0) return MI; // memset(d,c,0,a) -> noop
-
- // memset(s,c,n) -> store s, c (for n=1,2,4,8)
- if (Len <= 8 && isPowerOf2_32((uint32_t)Len)) {
- const Type *ITy = IntegerType::get(MI->getContext(), Len*8); // n=1 -> i8.
-
- Value *Dest = MI->getDest();
- Dest = Builder->CreateBitCast(Dest, PointerType::getUnqual(ITy));
-
- // Alignment 0 is identity for alignment 1 for memset, but not store.
- if (Alignment == 0) Alignment = 1;
-
- // Extract the fill value and store.
- uint64_t Fill = FillC->getZExtValue()*0x0101010101010101ULL;
- InsertNewInstBefore(new StoreInst(ConstantInt::get(ITy, Fill),
- Dest, false, Alignment), *MI);
-
- // Set the size of the copy to 0, it will be deleted on the next iteration.
- MI->setLength(Constant::getNullValue(LenC->getType()));
- return MI;
- }
-
- return 0;
-}
-
-
-/// visitCallInst - CallInst simplification. This mostly only handles folding
-/// of intrinsic instructions. For normal calls, it allows visitCallSite to do
-/// the heavy lifting.
-///
-Instruction *InstCombiner::visitCallInst(CallInst &CI) {
- if (isFreeCall(&CI))
- return visitFree(CI);
-
- // If the caller function is nounwind, mark the call as nounwind, even if the
- // callee isn't.
- if (CI.getParent()->getParent()->doesNotThrow() &&
- !CI.doesNotThrow()) {
- CI.setDoesNotThrow();
- return &CI;
- }
-
- IntrinsicInst *II = dyn_cast<IntrinsicInst>(&CI);
- if (!II) return visitCallSite(&CI);
-
- // Intrinsics cannot occur in an invoke, so handle them here instead of in
- // visitCallSite.
- if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(II)) {
- bool Changed = false;
-
- // memmove/cpy/set of zero bytes is a noop.
- if (Constant *NumBytes = dyn_cast<Constant>(MI->getLength())) {
- if (NumBytes->isNullValue()) return EraseInstFromFunction(CI);
-
- if (ConstantInt *CI = dyn_cast<ConstantInt>(NumBytes))
- if (CI->getZExtValue() == 1) {
- // Replace the instruction with just byte operations. We would
- // transform other cases to loads/stores, but we don't know if
- // alignment is sufficient.
- }
- }
-
- // If we have a memmove and the source operation is a constant global,
- // then the source and dest pointers can't alias, so we can change this
- // into a call to memcpy.
- if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) {
- if (GlobalVariable *GVSrc = dyn_cast<GlobalVariable>(MMI->getSource()))
- if (GVSrc->isConstant()) {
- Module *M = CI.getParent()->getParent()->getParent();
- Intrinsic::ID MemCpyID = Intrinsic::memcpy;
- const Type *Tys[1];
- Tys[0] = CI.getOperand(3)->getType();
- CI.setOperand(0,
- Intrinsic::getDeclaration(M, MemCpyID, Tys, 1));
- Changed = true;
- }
- }
-
- if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) {
- // memmove(x,x,size) -> noop.
- if (MTI->getSource() == MTI->getDest())
- return EraseInstFromFunction(CI);
- }
-
- // If we can determine a pointer alignment that is bigger than currently
- // set, update the alignment.
- if (isa<MemTransferInst>(MI)) {
- if (Instruction *I = SimplifyMemTransfer(MI))
- return I;
- } else if (MemSetInst *MSI = dyn_cast<MemSetInst>(MI)) {
- if (Instruction *I = SimplifyMemSet(MSI))
- return I;
- }
-
- if (Changed) return II;
- }
-
- switch (II->getIntrinsicID()) {
- default: break;
- case Intrinsic::bswap:
- // bswap(bswap(x)) -> x
- if (IntrinsicInst *Operand = dyn_cast<IntrinsicInst>(II->getOperand(1)))
- if (Operand->getIntrinsicID() == Intrinsic::bswap)
- return ReplaceInstUsesWith(CI, Operand->getOperand(1));
-
- // bswap(trunc(bswap(x))) -> trunc(lshr(x, c))
- if (TruncInst *TI = dyn_cast<TruncInst>(II->getOperand(1))) {
- if (IntrinsicInst *Operand = dyn_cast<IntrinsicInst>(TI->getOperand(0)))
- if (Operand->getIntrinsicID() == Intrinsic::bswap) {
- unsigned C = Operand->getType()->getPrimitiveSizeInBits() -
- TI->getType()->getPrimitiveSizeInBits();
- Value *CV = ConstantInt::get(Operand->getType(), C);
- Value *V = Builder->CreateLShr(Operand->getOperand(1), CV);
- return new TruncInst(V, TI->getType());
- }
- }
-
- break;
- case Intrinsic::powi:
- if (ConstantInt *Power = dyn_cast<ConstantInt>(II->getOperand(2))) {
- // powi(x, 0) -> 1.0
- if (Power->isZero())
- return ReplaceInstUsesWith(CI, ConstantFP::get(CI.getType(), 1.0));
- // powi(x, 1) -> x
- if (Power->isOne())
- return ReplaceInstUsesWith(CI, II->getOperand(1));
- // powi(x, -1) -> 1/x
- if (Power->isAllOnesValue())
- return BinaryOperator::CreateFDiv(ConstantFP::get(CI.getType(), 1.0),
- II->getOperand(1));
- }
- break;
-
- case Intrinsic::uadd_with_overflow: {
- Value *LHS = II->getOperand(1), *RHS = II->getOperand(2);
- const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType());
- uint32_t BitWidth = IT->getBitWidth();
- APInt Mask = APInt::getSignBit(BitWidth);
- APInt LHSKnownZero(BitWidth, 0);
- APInt LHSKnownOne(BitWidth, 0);
- ComputeMaskedBits(LHS, Mask, LHSKnownZero, LHSKnownOne);
- bool LHSKnownNegative = LHSKnownOne[BitWidth - 1];
- bool LHSKnownPositive = LHSKnownZero[BitWidth - 1];
-
- if (LHSKnownNegative || LHSKnownPositive) {
- APInt RHSKnownZero(BitWidth, 0);
- APInt RHSKnownOne(BitWidth, 0);
- ComputeMaskedBits(RHS, Mask, RHSKnownZero, RHSKnownOne);
- bool RHSKnownNegative = RHSKnownOne[BitWidth - 1];
- bool RHSKnownPositive = RHSKnownZero[BitWidth - 1];
- if (LHSKnownNegative && RHSKnownNegative) {
- // The sign bit is set in both cases: this MUST overflow.
- // Create a simple add instruction, and insert it into the struct.
- Instruction *Add = BinaryOperator::CreateAdd(LHS, RHS, "", &CI);
- Worklist.Add(Add);
- Constant *V[] = {
- UndefValue::get(LHS->getType()),ConstantInt::getTrue(II->getContext())
- };
- Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
- return InsertValueInst::Create(Struct, Add, 0);
- }
-
- if (LHSKnownPositive && RHSKnownPositive) {
- // The sign bit is clear in both cases: this CANNOT overflow.
- // Create a simple add instruction, and insert it into the struct.
- Instruction *Add = BinaryOperator::CreateNUWAdd(LHS, RHS, "", &CI);
- Worklist.Add(Add);
- Constant *V[] = {
- UndefValue::get(LHS->getType()),
- ConstantInt::getFalse(II->getContext())
- };
- Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
- return InsertValueInst::Create(Struct, Add, 0);
- }
- }
- }
- // FALL THROUGH uadd into sadd
- case Intrinsic::sadd_with_overflow:
- // Canonicalize constants into the RHS.
- if (isa<Constant>(II->getOperand(1)) &&
- !isa<Constant>(II->getOperand(2))) {
- Value *LHS = II->getOperand(1);
- II->setOperand(1, II->getOperand(2));
- II->setOperand(2, LHS);
- return II;
- }
-
- // X + undef -> undef
- if (isa<UndefValue>(II->getOperand(2)))
- return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
-
- if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getOperand(2))) {
- // X + 0 -> {X, false}
- if (RHS->isZero()) {
- Constant *V[] = {
- UndefValue::get(II->getOperand(0)->getType()),
- ConstantInt::getFalse(II->getContext())
- };
- Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
- return InsertValueInst::Create(Struct, II->getOperand(1), 0);
- }
- }
- break;
- case Intrinsic::usub_with_overflow:
- case Intrinsic::ssub_with_overflow:
- // undef - X -> undef
- // X - undef -> undef
- if (isa<UndefValue>(II->getOperand(1)) ||
- isa<UndefValue>(II->getOperand(2)))
- return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
-
- if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getOperand(2))) {
- // X - 0 -> {X, false}
- if (RHS->isZero()) {
- Constant *V[] = {
- UndefValue::get(II->getOperand(1)->getType()),
- ConstantInt::getFalse(II->getContext())
- };
- Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
- return InsertValueInst::Create(Struct, II->getOperand(1), 0);
- }
- }
- break;
- case Intrinsic::umul_with_overflow:
- case Intrinsic::smul_with_overflow:
- // Canonicalize constants into the RHS.
- if (isa<Constant>(II->getOperand(1)) &&
- !isa<Constant>(II->getOperand(2))) {
- Value *LHS = II->getOperand(1);
- II->setOperand(1, II->getOperand(2));
- II->setOperand(2, LHS);
- return II;
- }
-
- // X * undef -> undef
- if (isa<UndefValue>(II->getOperand(2)))
- return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
-
- if (ConstantInt *RHSI = dyn_cast<ConstantInt>(II->getOperand(2))) {
- // X*0 -> {0, false}
- if (RHSI->isZero())
- return ReplaceInstUsesWith(CI, Constant::getNullValue(II->getType()));
-
- // X * 1 -> {X, false}
- if (RHSI->equalsInt(1)) {
- Constant *V[] = {
- UndefValue::get(II->getOperand(1)->getType()),
- ConstantInt::getFalse(II->getContext())
- };
- Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
- return InsertValueInst::Create(Struct, II->getOperand(1), 0);
- }
- }
- break;
- case Intrinsic::ppc_altivec_lvx:
- case Intrinsic::ppc_altivec_lvxl:
- case Intrinsic::x86_sse_loadu_ps:
- case Intrinsic::x86_sse2_loadu_pd:
- case Intrinsic::x86_sse2_loadu_dq:
- // Turn PPC lvx -> load if the pointer is known aligned.
- // Turn X86 loadups -> load if the pointer is known aligned.
- if (GetOrEnforceKnownAlignment(II->getOperand(1), 16) >= 16) {
- Value *Ptr = Builder->CreateBitCast(II->getOperand(1),
- PointerType::getUnqual(II->getType()));
- return new LoadInst(Ptr);
- }
- break;
- case Intrinsic::ppc_altivec_stvx:
- case Intrinsic::ppc_altivec_stvxl:
- // Turn stvx -> store if the pointer is known aligned.
- if (GetOrEnforceKnownAlignment(II->getOperand(2), 16) >= 16) {
- const Type *OpPtrTy =
- PointerType::getUnqual(II->getOperand(1)->getType());
- Value *Ptr = Builder->CreateBitCast(II->getOperand(2), OpPtrTy);
- return new StoreInst(II->getOperand(1), Ptr);
- }
- break;
- case Intrinsic::x86_sse_storeu_ps:
- case Intrinsic::x86_sse2_storeu_pd:
- case Intrinsic::x86_sse2_storeu_dq:
- // Turn X86 storeu -> store if the pointer is known aligned.
- if (GetOrEnforceKnownAlignment(II->getOperand(1), 16) >= 16) {
- const Type *OpPtrTy =
- PointerType::getUnqual(II->getOperand(2)->getType());
- Value *Ptr = Builder->CreateBitCast(II->getOperand(1), OpPtrTy);
- return new StoreInst(II->getOperand(2), Ptr);
- }
- break;
-
- 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.
- 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;
- }
- break;
- }
-
- case Intrinsic::ppc_altivec_vperm:
- // Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant.
- if (ConstantVector *Mask = dyn_cast<ConstantVector>(II->getOperand(3))) {
- assert(Mask->getNumOperands() == 16 && "Bad type for intrinsic!");
-
- // Check that all of the elements are integer constants or undefs.
- bool AllEltsOk = true;
- for (unsigned i = 0; i != 16; ++i) {
- if (!isa<ConstantInt>(Mask->getOperand(i)) &&
- !isa<UndefValue>(Mask->getOperand(i))) {
- AllEltsOk = false;
- break;
- }
- }
-
- if (AllEltsOk) {
- // Cast the input vectors to byte vectors.
- Value *Op0 = Builder->CreateBitCast(II->getOperand(1), Mask->getType());
- Value *Op1 = Builder->CreateBitCast(II->getOperand(2), Mask->getType());
- Value *Result = UndefValue::get(Op0->getType());
-
- // Only extract each element once.
- Value *ExtractedElts[32];
- memset(ExtractedElts, 0, sizeof(ExtractedElts));
-
- for (unsigned i = 0; i != 16; ++i) {
- if (isa<UndefValue>(Mask->getOperand(i)))
- continue;
- unsigned Idx=cast<ConstantInt>(Mask->getOperand(i))->getZExtValue();
- Idx &= 31; // Match the hardware behavior.
-
- if (ExtractedElts[Idx] == 0) {
- ExtractedElts[Idx] =
- Builder->CreateExtractElement(Idx < 16 ? Op0 : Op1,
- ConstantInt::get(Type::getInt32Ty(II->getContext()),
- Idx&15, false), "tmp");
- }
-
- // Insert this value into the result vector.
- Result = Builder->CreateInsertElement(Result, ExtractedElts[Idx],
- ConstantInt::get(Type::getInt32Ty(II->getContext()),
- i, false), "tmp");
- }
- return CastInst::Create(Instruction::BitCast, Result, CI.getType());
- }
- }
- break;
-
- case Intrinsic::stackrestore: {
- // If the save is right next to the restore, remove the restore. This can
- // happen when variable allocas are DCE'd.
- if (IntrinsicInst *SS = dyn_cast<IntrinsicInst>(II->getOperand(1))) {
- if (SS->getIntrinsicID() == Intrinsic::stacksave) {
- BasicBlock::iterator BI = SS;
- if (&*++BI == II)
- return EraseInstFromFunction(CI);
- }
- }
-
- // Scan down this block to see if there is another stack restore in the
- // same block without an intervening call/alloca.
- BasicBlock::iterator BI = II;
- TerminatorInst *TI = II->getParent()->getTerminator();
- bool CannotRemove = false;
- for (++BI; &*BI != TI; ++BI) {
- if (isa<AllocaInst>(BI) || isMalloc(BI)) {
- CannotRemove = true;
- break;
- }
- if (CallInst *BCI = dyn_cast<CallInst>(BI)) {
- if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(BCI)) {
- // If there is a stackrestore below this one, remove this one.
- if (II->getIntrinsicID() == Intrinsic::stackrestore)
- return EraseInstFromFunction(CI);
- // Otherwise, ignore the intrinsic.
- } else {
- // If we found a non-intrinsic call, we can't remove the stack
- // restore.
- CannotRemove = true;
- break;
- }
- }
- }
-
- // If the stack restore is in a return/unwind block and if there are no
- // allocas or calls between the restore and the return, nuke the restore.
- if (!CannotRemove && (isa<ReturnInst>(TI) || isa<UnwindInst>(TI)))
- return EraseInstFromFunction(CI);
- break;
- }
- }
-
- return visitCallSite(II);
-}
-
-// InvokeInst simplification
-//
-Instruction *InstCombiner::visitInvokeInst(InvokeInst &II) {
- return visitCallSite(&II);
-}
-
-/// isSafeToEliminateVarargsCast - If this cast does not affect the value
-/// passed through the varargs area, we can eliminate the use of the cast.
-static bool isSafeToEliminateVarargsCast(const CallSite CS,
- const CastInst * const CI,
- const TargetData * const TD,
- const int ix) {
- if (!CI->isLosslessCast())
- return false;
-
- // The size of ByVal arguments is derived from the type, so we
- // can't change to a type with a different size. If the size were
- // passed explicitly we could avoid this check.
- if (!CS.paramHasAttr(ix, Attribute::ByVal))
- return true;
-
- const Type* SrcTy =
- cast<PointerType>(CI->getOperand(0)->getType())->getElementType();
- const Type* DstTy = cast<PointerType>(CI->getType())->getElementType();
- if (!SrcTy->isSized() || !DstTy->isSized())
- return false;
- if (!TD || TD->getTypeAllocSize(SrcTy) != TD->getTypeAllocSize(DstTy))
- return false;
- return true;
-}
-
-// visitCallSite - Improvements for call and invoke instructions.
-//
-Instruction *InstCombiner::visitCallSite(CallSite CS) {
- bool Changed = false;
-
- // If the callee is a constexpr cast of a function, attempt to move the cast
- // to the arguments of the call/invoke.
- if (transformConstExprCastCall(CS)) return 0;
-
- Value *Callee = CS.getCalledValue();
-
- if (Function *CalleeF = dyn_cast<Function>(Callee))
- if (CalleeF->getCallingConv() != CS.getCallingConv()) {
- Instruction *OldCall = CS.getInstruction();
- // If the call and callee calling conventions don't match, this call must
- // be unreachable, as the call is undefined.
- new StoreInst(ConstantInt::getTrue(Callee->getContext()),
- UndefValue::get(Type::getInt1PtrTy(Callee->getContext())),
- OldCall);
- // If OldCall dues not return void then replaceAllUsesWith undef.
- // This allows ValueHandlers and custom metadata to adjust itself.
- if (!OldCall->getType()->isVoidTy())
- OldCall->replaceAllUsesWith(UndefValue::get(OldCall->getType()));
- if (isa<CallInst>(OldCall)) // Not worth removing an invoke here.
- return EraseInstFromFunction(*OldCall);
- return 0;
- }
-
- if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) {
- // This instruction is not reachable, just remove it. We insert a store to
- // undef so that we know that this code is not reachable, despite the fact
- // that we can't modify the CFG here.
- new StoreInst(ConstantInt::getTrue(Callee->getContext()),
- UndefValue::get(Type::getInt1PtrTy(Callee->getContext())),
- CS.getInstruction());
-
- // If CS dues not return void then replaceAllUsesWith undef.
- // This allows ValueHandlers and custom metadata to adjust itself.
- if (!CS.getInstruction()->getType()->isVoidTy())
- CS.getInstruction()->
- replaceAllUsesWith(UndefValue::get(CS.getInstruction()->getType()));
-
- if (InvokeInst *II = dyn_cast<InvokeInst>(CS.getInstruction())) {
- // Don't break the CFG, insert a dummy cond branch.
- BranchInst::Create(II->getNormalDest(), II->getUnwindDest(),
- ConstantInt::getTrue(Callee->getContext()), II);
- }
- return EraseInstFromFunction(*CS.getInstruction());
- }
-
- if (BitCastInst *BC = dyn_cast<BitCastInst>(Callee))
- if (IntrinsicInst *In = dyn_cast<IntrinsicInst>(BC->getOperand(0)))
- if (In->getIntrinsicID() == Intrinsic::init_trampoline)
- return transformCallThroughTrampoline(CS);
-
- const PointerType *PTy = cast<PointerType>(Callee->getType());
- const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
- if (FTy->isVarArg()) {
- int ix = FTy->getNumParams() + (isa<InvokeInst>(Callee) ? 3 : 1);
- // See if we can optimize any arguments passed through the varargs area of
- // the call.
- for (CallSite::arg_iterator I = CS.arg_begin()+FTy->getNumParams(),
- E = CS.arg_end(); I != E; ++I, ++ix) {
- CastInst *CI = dyn_cast<CastInst>(*I);
- if (CI && isSafeToEliminateVarargsCast(CS, CI, TD, ix)) {
- *I = CI->getOperand(0);
- Changed = true;
- }
- }
- }
-
- if (isa<InlineAsm>(Callee) && !CS.doesNotThrow()) {
- // Inline asm calls cannot throw - mark them 'nounwind'.
- CS.setDoesNotThrow();
- Changed = true;
- }
-
- return Changed ? CS.getInstruction() : 0;
-}
-
-// transformConstExprCastCall - If the callee is a constexpr cast of a function,
-// attempt to move the cast to the arguments of the call/invoke.
-//
-bool InstCombiner::transformConstExprCastCall(CallSite CS) {
- if (!isa<ConstantExpr>(CS.getCalledValue())) return false;
- ConstantExpr *CE = cast<ConstantExpr>(CS.getCalledValue());
- if (CE->getOpcode() != Instruction::BitCast ||
- !isa<Function>(CE->getOperand(0)))
- return false;
- Function *Callee = cast<Function>(CE->getOperand(0));
- Instruction *Caller = CS.getInstruction();
- const AttrListPtr &CallerPAL = CS.getAttributes();
-
- // Okay, this is a cast from a function to a different type. Unless doing so
- // would cause a type conversion of one of our arguments, change this call to
- // be a direct call with arguments casted to the appropriate types.
- //
- const FunctionType *FT = Callee->getFunctionType();
- const Type *OldRetTy = Caller->getType();
- const Type *NewRetTy = FT->getReturnType();
-
- if (isa<StructType>(NewRetTy))
- return false; // TODO: Handle multiple return values.
-
- // Check to see if we are changing the return type...
- if (OldRetTy != NewRetTy) {
- if (Callee->isDeclaration() &&
- // Conversion is ok if changing from one pointer type to another or from
- // a pointer to an integer of the same size.
- !((isa<PointerType>(OldRetTy) || !TD ||
- OldRetTy == TD->getIntPtrType(Caller->getContext())) &&
- (isa<PointerType>(NewRetTy) || !TD ||
- NewRetTy == TD->getIntPtrType(Caller->getContext()))))
- return false; // Cannot transform this return value.
-
- if (!Caller->use_empty() &&
- // void -> non-void is handled specially
- !NewRetTy->isVoidTy() && !CastInst::isCastable(NewRetTy, OldRetTy))
- return false; // Cannot transform this return value.
-
- if (!CallerPAL.isEmpty() && !Caller->use_empty()) {
- Attributes RAttrs = CallerPAL.getRetAttributes();
- if (RAttrs & Attribute::typeIncompatible(NewRetTy))
- return false; // Attribute not compatible with transformed value.
- }
-
- // If the callsite is an invoke instruction, and the return value is used by
- // a PHI node in a successor, we cannot change the return type of the call
- // because there is no place to put the cast instruction (without breaking
- // the critical edge). Bail out in this case.
- if (!Caller->use_empty())
- if (InvokeInst *II = dyn_cast<InvokeInst>(Caller))
- for (Value::use_iterator UI = II->use_begin(), E = II->use_end();
- UI != E; ++UI)
- if (PHINode *PN = dyn_cast<PHINode>(*UI))
- if (PN->getParent() == II->getNormalDest() ||
- PN->getParent() == II->getUnwindDest())
- return false;
- }
-
- unsigned NumActualArgs = unsigned(CS.arg_end()-CS.arg_begin());
- unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs);
-
- CallSite::arg_iterator AI = CS.arg_begin();
- for (unsigned i = 0, e = NumCommonArgs; i != e; ++i, ++AI) {
- const Type *ParamTy = FT->getParamType(i);
- const Type *ActTy = (*AI)->getType();
-
- if (!CastInst::isCastable(ActTy, ParamTy))
- return false; // Cannot transform this parameter value.
-
- if (CallerPAL.getParamAttributes(i + 1)
- & Attribute::typeIncompatible(ParamTy))
- return false; // Attribute not compatible with transformed value.
-
- // Converting from one pointer type to another or between a pointer and an
- // integer of the same size is safe even if we do not have a body.
- bool isConvertible = ActTy == ParamTy ||
- (TD && ((isa<PointerType>(ParamTy) ||
- ParamTy == TD->getIntPtrType(Caller->getContext())) &&
- (isa<PointerType>(ActTy) ||
- ActTy == TD->getIntPtrType(Caller->getContext()))));
- if (Callee->isDeclaration() && !isConvertible) return false;
- }
-
- if (FT->getNumParams() < NumActualArgs && !FT->isVarArg() &&
- Callee->isDeclaration())
- return false; // Do not delete arguments unless we have a function body.
-
- if (FT->getNumParams() < NumActualArgs && FT->isVarArg() &&
- !CallerPAL.isEmpty())
- // In this case we have more arguments than the new function type, but we
- // won't be dropping them. Check that these extra arguments have attributes
- // that are compatible with being a vararg call argument.
- for (unsigned i = CallerPAL.getNumSlots(); i; --i) {
- if (CallerPAL.getSlot(i - 1).Index <= FT->getNumParams())
- break;
- Attributes PAttrs = CallerPAL.getSlot(i - 1).Attrs;
- if (PAttrs & Attribute::VarArgsIncompatible)
- return false;
- }
-
- // Okay, we decided that this is a safe thing to do: go ahead and start
- // inserting cast instructions as necessary...
- std::vector<Value*> Args;
- Args.reserve(NumActualArgs);
- SmallVector<AttributeWithIndex, 8> attrVec;
- attrVec.reserve(NumCommonArgs);
-
- // Get any return attributes.
- Attributes RAttrs = CallerPAL.getRetAttributes();
-
- // If the return value is not being used, the type may not be compatible
- // with the existing attributes. Wipe out any problematic attributes.
- RAttrs &= ~Attribute::typeIncompatible(NewRetTy);
-
- // Add the new return attributes.
- if (RAttrs)
- attrVec.push_back(AttributeWithIndex::get(0, RAttrs));
-
- AI = CS.arg_begin();
- for (unsigned i = 0; i != NumCommonArgs; ++i, ++AI) {
- const Type *ParamTy = FT->getParamType(i);
- if ((*AI)->getType() == ParamTy) {
- Args.push_back(*AI);
- } else {
- Instruction::CastOps opcode = CastInst::getCastOpcode(*AI,
- false, ParamTy, false);
- Args.push_back(Builder->CreateCast(opcode, *AI, ParamTy, "tmp"));
- }
-
- // Add any parameter attributes.
- if (Attributes PAttrs = CallerPAL.getParamAttributes(i + 1))
- attrVec.push_back(AttributeWithIndex::get(i + 1, PAttrs));
- }
-
- // If the function takes more arguments than the call was taking, add them
- // now.
- for (unsigned i = NumCommonArgs; i != FT->getNumParams(); ++i)
- Args.push_back(Constant::getNullValue(FT->getParamType(i)));
-
- // If we are removing arguments to the function, emit an obnoxious warning.
- if (FT->getNumParams() < NumActualArgs) {
- if (!FT->isVarArg()) {
- errs() << "WARNING: While resolving call to function '"
- << Callee->getName() << "' arguments were dropped!\n";
- } else {
- // Add all of the arguments in their promoted form to the arg list.
- for (unsigned i = FT->getNumParams(); i != NumActualArgs; ++i, ++AI) {
- const Type *PTy = getPromotedType((*AI)->getType());
- if (PTy != (*AI)->getType()) {
- // Must promote to pass through va_arg area!
- Instruction::CastOps opcode =
- CastInst::getCastOpcode(*AI, false, PTy, false);
- Args.push_back(Builder->CreateCast(opcode, *AI, PTy, "tmp"));
- } else {
- Args.push_back(*AI);
- }
-
- // Add any parameter attributes.
- if (Attributes PAttrs = CallerPAL.getParamAttributes(i + 1))
- attrVec.push_back(AttributeWithIndex::get(i + 1, PAttrs));
- }
- }
- }
-
- if (Attributes FnAttrs = CallerPAL.getFnAttributes())
- attrVec.push_back(AttributeWithIndex::get(~0, FnAttrs));
-
- if (NewRetTy->isVoidTy())
- Caller->setName(""); // Void type should not have a name.
-
- const AttrListPtr &NewCallerPAL = AttrListPtr::get(attrVec.begin(),
- attrVec.end());
-
- Instruction *NC;
- if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
- NC = InvokeInst::Create(Callee, II->getNormalDest(), II->getUnwindDest(),
- Args.begin(), Args.end(),
- Caller->getName(), Caller);
- cast<InvokeInst>(NC)->setCallingConv(II->getCallingConv());
- cast<InvokeInst>(NC)->setAttributes(NewCallerPAL);
- } else {
- NC = CallInst::Create(Callee, Args.begin(), Args.end(),
- Caller->getName(), Caller);
- CallInst *CI = cast<CallInst>(Caller);
- if (CI->isTailCall())
- cast<CallInst>(NC)->setTailCall();
- cast<CallInst>(NC)->setCallingConv(CI->getCallingConv());
- cast<CallInst>(NC)->setAttributes(NewCallerPAL);
- }
-
- // Insert a cast of the return type as necessary.
- Value *NV = NC;
- if (OldRetTy != NV->getType() && !Caller->use_empty()) {
- if (!NV->getType()->isVoidTy()) {
- Instruction::CastOps opcode = CastInst::getCastOpcode(NC, false,
- OldRetTy, false);
- NV = NC = CastInst::Create(opcode, NC, OldRetTy, "tmp");
-
- // If this is an invoke instruction, we should insert it after the first
- // non-phi, instruction in the normal successor block.
- if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
- BasicBlock::iterator I = II->getNormalDest()->getFirstNonPHI();
- InsertNewInstBefore(NC, *I);
- } else {
- // Otherwise, it's a call, just insert cast right after the call instr
- InsertNewInstBefore(NC, *Caller);
- }
- Worklist.AddUsersToWorkList(*Caller);
- } else {
- NV = UndefValue::get(Caller->getType());
- }
- }
-
-
- if (!Caller->use_empty())
- Caller->replaceAllUsesWith(NV);
-
- EraseInstFromFunction(*Caller);
- return true;
-}
-
-// transformCallThroughTrampoline - Turn a call to a function created by the
-// init_trampoline intrinsic into a direct call to the underlying function.
-//
-Instruction *InstCombiner::transformCallThroughTrampoline(CallSite CS) {
- Value *Callee = CS.getCalledValue();
- const PointerType *PTy = cast<PointerType>(Callee->getType());
- const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
- const AttrListPtr &Attrs = CS.getAttributes();
-
- // If the call already has the 'nest' attribute somewhere then give up -
- // otherwise 'nest' would occur twice after splicing in the chain.
- if (Attrs.hasAttrSomewhere(Attribute::Nest))
- return 0;
-
- IntrinsicInst *Tramp =
- cast<IntrinsicInst>(cast<BitCastInst>(Callee)->getOperand(0));
-
- Function *NestF = cast<Function>(Tramp->getOperand(2)->stripPointerCasts());
- const PointerType *NestFPTy = cast<PointerType>(NestF->getType());
- const FunctionType *NestFTy = cast<FunctionType>(NestFPTy->getElementType());
-
- const AttrListPtr &NestAttrs = NestF->getAttributes();
- if (!NestAttrs.isEmpty()) {
- unsigned NestIdx = 1;
- const Type *NestTy = 0;
- Attributes NestAttr = Attribute::None;
-
- // Look for a parameter marked with the 'nest' attribute.
- for (FunctionType::param_iterator I = NestFTy->param_begin(),
- E = NestFTy->param_end(); I != E; ++NestIdx, ++I)
- if (NestAttrs.paramHasAttr(NestIdx, Attribute::Nest)) {
- // Record the parameter type and any other attributes.
- NestTy = *I;
- NestAttr = NestAttrs.getParamAttributes(NestIdx);
- break;
- }
-
- if (NestTy) {
- Instruction *Caller = CS.getInstruction();
- std::vector<Value*> NewArgs;
- NewArgs.reserve(unsigned(CS.arg_end()-CS.arg_begin())+1);
-
- SmallVector<AttributeWithIndex, 8> NewAttrs;
- NewAttrs.reserve(Attrs.getNumSlots() + 1);
-
- // Insert the nest argument into the call argument list, which may
- // mean appending it. Likewise for attributes.
-
- // Add any result attributes.
- if (Attributes Attr = Attrs.getRetAttributes())
- NewAttrs.push_back(AttributeWithIndex::get(0, Attr));
-
- {
- unsigned Idx = 1;
- CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
- do {
- if (Idx == NestIdx) {
- // Add the chain argument and attributes.
- Value *NestVal = Tramp->getOperand(3);
- if (NestVal->getType() != NestTy)
- NestVal = new BitCastInst(NestVal, NestTy, "nest", Caller);
- NewArgs.push_back(NestVal);
- NewAttrs.push_back(AttributeWithIndex::get(NestIdx, NestAttr));
- }
-
- if (I == E)
- break;
-
- // Add the original argument and attributes.
- NewArgs.push_back(*I);
- if (Attributes Attr = Attrs.getParamAttributes(Idx))
- NewAttrs.push_back
- (AttributeWithIndex::get(Idx + (Idx >= NestIdx), Attr));
-
- ++Idx, ++I;
- } while (1);
- }
-
- // Add any function attributes.
- if (Attributes Attr = Attrs.getFnAttributes())
- NewAttrs.push_back(AttributeWithIndex::get(~0, Attr));
-
- // The trampoline may have been bitcast to a bogus type (FTy).
- // Handle this by synthesizing a new function type, equal to FTy
- // with the chain parameter inserted.
-
- std::vector<const Type*> NewTypes;
- NewTypes.reserve(FTy->getNumParams()+1);
-
- // Insert the chain's type into the list of parameter types, which may
- // mean appending it.
- {
- unsigned Idx = 1;
- FunctionType::param_iterator I = FTy->param_begin(),
- E = FTy->param_end();
-
- do {
- if (Idx == NestIdx)
- // Add the chain's type.
- NewTypes.push_back(NestTy);
-
- if (I == E)
- break;
-
- // Add the original type.
- NewTypes.push_back(*I);
-
- ++Idx, ++I;
- } while (1);
- }
-
- // Replace the trampoline call with a direct call. Let the generic
- // code sort out any function type mismatches.
- FunctionType *NewFTy = FunctionType::get(FTy->getReturnType(), NewTypes,
- FTy->isVarArg());
- Constant *NewCallee =
- NestF->getType() == PointerType::getUnqual(NewFTy) ?
- NestF : ConstantExpr::getBitCast(NestF,
- PointerType::getUnqual(NewFTy));
- const AttrListPtr &NewPAL = AttrListPtr::get(NewAttrs.begin(),
- NewAttrs.end());
-
- Instruction *NewCaller;
- if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
- NewCaller = InvokeInst::Create(NewCallee,
- II->getNormalDest(), II->getUnwindDest(),
- NewArgs.begin(), NewArgs.end(),
- Caller->getName(), Caller);
- cast<InvokeInst>(NewCaller)->setCallingConv(II->getCallingConv());
- cast<InvokeInst>(NewCaller)->setAttributes(NewPAL);
- } else {
- NewCaller = CallInst::Create(NewCallee, NewArgs.begin(), NewArgs.end(),
- Caller->getName(), Caller);
- if (cast<CallInst>(Caller)->isTailCall())
- cast<CallInst>(NewCaller)->setTailCall();
- cast<CallInst>(NewCaller)->
- setCallingConv(cast<CallInst>(Caller)->getCallingConv());
- cast<CallInst>(NewCaller)->setAttributes(NewPAL);
- }
- if (!Caller->getType()->isVoidTy())
- Caller->replaceAllUsesWith(NewCaller);
- Caller->eraseFromParent();
- Worklist.Remove(Caller);
- return 0;
- }
- }
-
- // Replace the trampoline call with a direct call. Since there is no 'nest'
- // parameter, there is no need to adjust the argument list. Let the generic
- // code sort out any function type mismatches.
- Constant *NewCallee =
- NestF->getType() == PTy ? NestF :
- ConstantExpr::getBitCast(NestF, PTy);
- CS.setCalledFunction(NewCallee);
- return CS.getInstruction();
-}
-
-
-
-Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
- SmallVector<Value*, 8> Ops(GEP.op_begin(), GEP.op_end());
-
- if (Value *V = SimplifyGEPInst(&Ops[0], Ops.size(), TD))
- return ReplaceInstUsesWith(GEP, V);
-
- Value *PtrOp = GEP.getOperand(0);
-
- if (isa<UndefValue>(GEP.getOperand(0)))
- return ReplaceInstUsesWith(GEP, UndefValue::get(GEP.getType()));
-
- // Eliminate unneeded casts for indices.
- if (TD) {
- bool MadeChange = false;
- unsigned PtrSize = TD->getPointerSizeInBits();
-
- gep_type_iterator GTI = gep_type_begin(GEP);
- for (User::op_iterator I = GEP.op_begin() + 1, E = GEP.op_end();
- I != E; ++I, ++GTI) {
- if (!isa<SequentialType>(*GTI)) continue;
-
- // If we are using a wider index than needed for this platform, shrink it
- // to what we need. If narrower, sign-extend it to what we need. This
- // explicit cast can make subsequent optimizations more obvious.
- unsigned OpBits = cast<IntegerType>((*I)->getType())->getBitWidth();
- if (OpBits == PtrSize)
- continue;
-
- *I = Builder->CreateIntCast(*I, TD->getIntPtrType(GEP.getContext()),true);
- MadeChange = true;
- }
- if (MadeChange) return &GEP;
- }
-
- // 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.
- //
- if (GEPOperator *Src = dyn_cast<GEPOperator>(PtrOp)) {
- // Note that if our source is a gep chain itself that we wait for that
- // chain to be resolved before we perform this transformation. This
- // avoids us creating a TON of code in some cases.
- //
- if (GetElementPtrInst *SrcGEP =
- dyn_cast<GetElementPtrInst>(Src->getOperand(0)))
- if (SrcGEP->getNumOperands() == 2)
- return 0; // Wait until our source is folded to completion.
-
- SmallVector<Value*, 8> Indices;
-
- // Find out whether the last index in the source GEP is a sequential idx.
- bool EndsWithSequential = false;
- for (gep_type_iterator I = gep_type_begin(*Src), E = gep_type_end(*Src);
- I != E; ++I)
- EndsWithSequential = !isa<StructType>(*I);
-
- // Can we combine the two pointer arithmetics offsets?
- if (EndsWithSequential) {
- // Replace: gep (gep %P, long B), long A, ...
- // With: T = long A+B; gep %P, T, ...
- //
- Value *Sum;
- Value *SO1 = Src->getOperand(Src->getNumOperands()-1);
- Value *GO1 = GEP.getOperand(1);
- if (SO1 == Constant::getNullValue(SO1->getType())) {
- Sum = GO1;
- } else if (GO1 == Constant::getNullValue(GO1->getType())) {
- Sum = SO1;
- } else {
- // If they aren't the same type, then the input hasn't been processed
- // by the loop above yet (which canonicalizes sequential index types to
- // intptr_t). Just avoid transforming this until the input has been
- // normalized.
- if (SO1->getType() != GO1->getType())
- return 0;
- Sum = Builder->CreateAdd(SO1, GO1, PtrOp->getName()+".sum");
- }
-
- // Update the GEP in place if possible.
- if (Src->getNumOperands() == 2) {
- GEP.setOperand(0, Src->getOperand(0));
- GEP.setOperand(1, Sum);
- return &GEP;
- }
- Indices.append(Src->op_begin()+1, Src->op_end()-1);
- Indices.push_back(Sum);
- Indices.append(GEP.op_begin()+2, GEP.op_end());
- } else if (isa<Constant>(*GEP.idx_begin()) &&
- cast<Constant>(*GEP.idx_begin())->isNullValue() &&
- Src->getNumOperands() != 1) {
- // Otherwise we can do the fold if the first index of the GEP is a zero
- Indices.append(Src->op_begin()+1, Src->op_end());
- Indices.append(GEP.idx_begin()+1, GEP.idx_end());
- }
-
- if (!Indices.empty())
- return (cast<GEPOperator>(&GEP)->isInBounds() &&
- Src->isInBounds()) ?
- GetElementPtrInst::CreateInBounds(Src->getOperand(0), Indices.begin(),
- Indices.end(), GEP.getName()) :
- GetElementPtrInst::Create(Src->getOperand(0), Indices.begin(),
- Indices.end(), GEP.getName());
- }
-
- // Handle gep(bitcast x) and gep(gep x, 0, 0, 0).
- if (Value *X = getBitCastOperand(PtrOp)) {
- assert(isa<PointerType>(X->getType()) && "Must be cast from pointer");
-
- // If the input bitcast is actually "bitcast(bitcast(x))", then we don't
- // want to change the gep until the bitcasts are eliminated.
- if (getBitCastOperand(X)) {
- Worklist.AddValue(PtrOp);
- return 0;
- }
-
bool HasZeroPointerIndex = false;
if (ConstantInt *C = dyn_cast<ConstantInt>(GEP.getOperand(1)))
HasZeroPointerIndex = C->isZero();
// This occurs when the program declares an array extern like "int X[];"
if (HasZeroPointerIndex) {
const PointerType *CPTy = cast<PointerType>(PtrOp->getType());
- const PointerType *XTy = cast<PointerType>(X->getType());
if (const ArrayType *CATy =
dyn_cast<ArrayType>(CPTy->getElementType())) {
// GEP (bitcast i8* X to [0 x i8]*), i32 0, ... ?
- if (CATy->getElementType() == XTy->getElementType()) {
+ if (CATy->getElementType() == StrippedPtrTy->getElementType()) {
// -> GEP i8* X, ...
- SmallVector<Value*, 8> Indices(GEP.idx_begin()+1, GEP.idx_end());
- return cast<GEPOperator>(&GEP)->isInBounds() ?
- GetElementPtrInst::CreateInBounds(X, Indices.begin(), Indices.end(),
- GEP.getName()) :
- GetElementPtrInst::Create(X, Indices.begin(), Indices.end(),
- GEP.getName());
+ SmallVector<Value*, 8> Idx(GEP.idx_begin()+1, GEP.idx_end());
+ GetElementPtrInst *Res =
+ GetElementPtrInst::Create(StrippedPtr, Idx.begin(),
+ Idx.end(), GEP.getName());
+ Res->setIsInBounds(GEP.isInBounds());
+ return Res;
}
- if (const ArrayType *XATy = dyn_cast<ArrayType>(XTy->getElementType())){
+ if (const ArrayType *XATy =
+ dyn_cast<ArrayType>(StrippedPtrTy->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, ...
// to an array of the same type as the destination pointer
// array. Because the array type is never stepped over (there
// is a leading zero) we can fold the cast into this GEP.
- GEP.setOperand(0, X);
+ GEP.setOperand(0, StrippedPtr);
return &GEP;
}
}
// Transform things like:
// %t = getelementptr i32* bitcast ([2 x i32]* %str to i32*), i32 %V
// into: %t1 = getelementptr [2 x i32]* %str, i32 0, i32 %V; bitcast
- const Type *SrcElTy = cast<PointerType>(X->getType())->getElementType();
+ const Type *SrcElTy = StrippedPtrTy->getElementType();
const Type *ResElTy=cast<PointerType>(PtrOp->getType())->getElementType();
if (TD && isa<ArrayType>(SrcElTy) &&
TD->getTypeAllocSize(cast<ArrayType>(SrcElTy)->getElementType()) ==
Value *Idx[2];
Idx[0] = Constant::getNullValue(Type::getInt32Ty(GEP.getContext()));
Idx[1] = GEP.getOperand(1);
- Value *NewGEP = cast<GEPOperator>(&GEP)->isInBounds() ?
- Builder->CreateInBoundsGEP(X, Idx, Idx + 2, GEP.getName()) :
- Builder->CreateGEP(X, Idx, Idx + 2, GEP.getName());
+ Value *NewGEP = GEP.isInBounds() ?
+ Builder->CreateInBoundsGEP(StrippedPtr, Idx, Idx + 2, GEP.getName()) :
+ Builder->CreateGEP(StrippedPtr, Idx, Idx + 2, GEP.getName());
// V and GEP are both pointer types --> BitCast
return new BitCastInst(NewGEP, GEP.getType());
}
Value *Idx[2];
Idx[0] = Constant::getNullValue(Type::getInt32Ty(GEP.getContext()));
Idx[1] = NewIdx;
- Value *NewGEP = cast<GEPOperator>(&GEP)->isInBounds() ?
- Builder->CreateInBoundsGEP(X, Idx, Idx + 2, GEP.getName()) :
- Builder->CreateGEP(X, Idx, Idx + 2, GEP.getName());
+ Value *NewGEP = GEP.isInBounds() ?
+ Builder->CreateInBoundsGEP(StrippedPtr, Idx, Idx + 2,GEP.getName()):
+ Builder->CreateGEP(StrippedPtr, Idx, Idx + 2, GEP.getName());
// The NewGEP must be pointer typed, so must the old one -> BitCast
return new BitCastInst(NewGEP, GEP.getType());
}
const Type *InTy =
cast<PointerType>(BCI->getOperand(0)->getType())->getElementType();
if (FindElementAtOffset(InTy, Offset, NewIndices)) {
- Value *NGEP = cast<GEPOperator>(&GEP)->isInBounds() ?
+ Value *NGEP = GEP.isInBounds() ?
Builder->CreateInBoundsGEP(BCI->getOperand(0), NewIndices.begin(),
NewIndices.end()) :
Builder->CreateGEP(BCI->getOperand(0), NewIndices.begin(),
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