#define DEBUG_TYPE "instcombine"
-/// 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))
+ if (!IsFreeToInvert(Operand, Operand->hasOneUse()))
return Operand;
}
return nullptr;
}
-/// 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.
+/// 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) {
}
}
-/// getNewICmpValue - 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.
+/// 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 *getNewICmpValue(bool Sign, unsigned Code, Value *LHS, Value *RHS,
InstCombiner::BuilderTy *Builder) {
ICmpInst::Predicate NewPred;
return Builder->CreateICmp(NewPred, LHS, RHS);
}
-/// 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.
+/// 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,
InstCombiner::BuilderTy *Builder) {
case 5: Pred = isordered ? FCmpInst::FCMP_ONE : FCmpInst::FCMP_UNE; break;
case 6: Pred = isordered ? FCmpInst::FCMP_OLE : FCmpInst::FCMP_ULE; break;
case 7:
- if (!isordered) return ConstantInt::getTrue(LHS->getContext());
+ if (!isordered)
+ return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 1);
Pred = FCmpInst::FCMP_ORD; break;
}
return Builder->CreateFCmp(Pred, LHS, RHS);
return Builder->CreateCall(F, BinOp);
}
-// 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.
+/// 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,
return Builder->CreateICmpUGT(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.
+/// 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();
return true;
}
-/// 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:
+/// 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
FoldMskICmp_BMask_NotMixed = 512
};
-/// return the set of pattern classes (from MaskedICmpType)
-/// that (icmp SCC (A & B), C) satisfies
+/// Return the set of pattern classes (from MaskedICmpType)
+/// that (icmp SCC (A & B), C) satisfies.
static unsigned getTypeOfMaskedICmp(Value* A, Value* B, Value* C,
ICmpInst::Predicate SCC)
{
return NewMask;
}
-/// decomposeBitTestICmp - Decompose an icmp into the form ((X & Y) pred Z)
-/// if possible. The returned predicate is either == or !=. Returns false if
+/// Decompose an icmp into the form ((X & Y) pred Z) if possible.
+/// The returned predicate is either == or !=. Returns false if
/// decomposition fails.
static bool decomposeBitTestICmp(const ICmpInst *I, ICmpInst::Predicate &Pred,
Value *&X, Value *&Y, Value *&Z) {
return true;
}
-/// foldLogOpOfMaskedICmpsHelper:
-/// handle (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E)
-/// return the set of pattern classes (from MaskedICmpType)
-/// that both LHS and RHS satisfy
+/// Handle (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E)
+/// Return the set of pattern classes (from MaskedICmpType)
+/// that both LHS and RHS satisfy.
static unsigned foldLogOpOfMaskedICmpsHelper(Value*& A,
Value*& B, Value*& C,
Value*& D, Value*& E,
unsigned right_type = getTypeOfMaskedICmp(A, D, E, RHSCC);
return left_type & right_type;
}
-/// foldLogOpOfMaskedICmps:
-/// try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E)
-/// into a single (icmp(A & X) ==/!= Y)
+
+/// Try to fold (icmp(A & B) ==/!= C) &/| (icmp(A & D) ==/!= E)
+/// into a single (icmp(A & X) ==/!= Y).
static Value *foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS, bool IsAnd,
llvm::InstCombiner::BuilderTy *Builder) {
Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr, *E = nullptr;
return Builder->CreateICmp(NewPred, Input, RangeEnd);
}
-/// FoldAndOfICmps - Fold (icmp)&(icmp) if possible.
+/// Fold (icmp)&(icmp) if possible.
Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
// Make a constant range that's the intersection of the two icmp ranges.
// If the intersection is empty, we know that the result is false.
ConstantRange LHSRange =
- ConstantRange::makeICmpRegion(LHSCC, LHSCst->getValue());
+ ConstantRange::makeAllowedICmpRegion(LHSCC, LHSCst->getValue());
ConstantRange RHSRange =
- ConstantRange::makeICmpRegion(RHSCC, RHSCst->getValue());
+ ConstantRange::makeAllowedICmpRegion(RHSCC, RHSCst->getValue());
if (LHSRange.intersectWith(RHSRange).isEmptySet())
return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
return nullptr;
}
-/// FoldAndOfFCmps - Optimize (fcmp)&(fcmp). NOTE: Unlike the rest of
-/// instcombine, this returns a Value which should already be inserted into the
-/// function.
+/// Optimize (fcmp)&(fcmp). NOTE: Unlike the rest of instcombine, this returns
+/// a Value which should already be inserted into the function.
Value *InstCombiner::FoldAndOfFCmps(FCmpInst *LHS, FCmpInst *RHS) {
if (LHS->getPredicate() == FCmpInst::FCMP_ORD &&
RHS->getPredicate() == FCmpInst::FCMP_ORD) {
return nullptr;
}
+/// Match De Morgan's Laws:
+/// (~A & ~B) == (~(A | B))
+/// (~A | ~B) == (~(A & B))
+static Instruction *matchDeMorgansLaws(BinaryOperator &I,
+ InstCombiner::BuilderTy *Builder) {
+ auto Opcode = I.getOpcode();
+ assert((Opcode == Instruction::And || Opcode == Instruction::Or) &&
+ "Trying to match De Morgan's Laws with something other than and/or");
+
+ Value *Op0 = I.getOperand(0);
+ Value *Op1 = I.getOperand(1);
+ // TODO: Use pattern matchers instead of dyn_cast.
+ if (Value *Op0NotVal = dyn_castNotVal(Op0))
+ if (Value *Op1NotVal = dyn_castNotVal(Op1))
+ if (Op0->hasOneUse() && Op1->hasOneUse()) {
+ // Flip the logic operation.
+ if (Opcode == Instruction::And)
+ Opcode = Instruction::Or;
+ else
+ Opcode = Instruction::And;
+ Value *LogicOp = Builder->CreateBinOp(Opcode, Op0NotVal, Op1NotVal,
+ I.getName() + ".demorgan");
+ return BinaryOperator::CreateNot(LogicOp);
+ }
+
+ return nullptr;
+}
+
Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
bool Changed = SimplifyAssociativeOrCommutative(I);
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
if (Value *V = FoldLogicalPlusAnd(Op0LHS, Op0RHS, AndRHS, true, I))
return BinaryOperator::CreateAnd(V, AndRHS);
+ // -x & 1 -> x & 1
+ if (AndRHSMask == 1 && match(Op0LHS, m_Zero()))
+ return BinaryOperator::CreateAnd(Op0RHS, 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() && !match(Op0LHS, m_Zero())) {
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);
- }
+ if (Instruction *DeMorgan = matchDeMorgansLaws(I, Builder))
+ return DeMorgan;
{
Value *A = nullptr, *B = nullptr, *C = nullptr, *D = nullptr;
return Changed ? &I : nullptr;
}
-/// 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
+/// 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
return false;
}
-/// MatchBSwap - Given an OR instruction, check to see if this is a bswap idiom.
+/// 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) {
IntegerType *ITy = dyn_cast<IntegerType>(I.getType());
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".
+/// 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.
return nullptr;
}
-/// FoldOrOfICmps - Fold (icmp)|(icmp) if possible.
+/// Fold (icmp)|(icmp) if possible.
Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
Instruction *CxtI) {
ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
Value *Mask = nullptr;
Value *Masked = nullptr;
if (LAnd->getOperand(0) == RAnd->getOperand(0) &&
- isKnownToBeAPowerOfTwo(LAnd->getOperand(1), false, 0, AC, CxtI, DT) &&
- isKnownToBeAPowerOfTwo(RAnd->getOperand(1), false, 0, AC, CxtI, DT)) {
+ isKnownToBeAPowerOfTwo(LAnd->getOperand(1), DL, false, 0, AC, CxtI,
+ DT) &&
+ isKnownToBeAPowerOfTwo(RAnd->getOperand(1), DL, false, 0, AC, CxtI,
+ DT)) {
Mask = Builder->CreateOr(LAnd->getOperand(1), RAnd->getOperand(1));
Masked = Builder->CreateAnd(LAnd->getOperand(0), Mask);
} else if (LAnd->getOperand(1) == RAnd->getOperand(1) &&
- isKnownToBeAPowerOfTwo(LAnd->getOperand(0), false, 0, AC, CxtI,
- DT) &&
- isKnownToBeAPowerOfTwo(RAnd->getOperand(0), false, 0, AC, CxtI,
- DT)) {
+ isKnownToBeAPowerOfTwo(LAnd->getOperand(0), DL, false, 0, AC,
+ CxtI, DT) &&
+ isKnownToBeAPowerOfTwo(RAnd->getOperand(0), DL, false, 0, AC,
+ CxtI, DT)) {
Mask = Builder->CreateOr(LAnd->getOperand(0), RAnd->getOperand(0));
Masked = Builder->CreateAnd(LAnd->getOperand(1), Mask);
}
return nullptr;
}
-/// FoldOrOfFCmps - Optimize (fcmp)|(fcmp). NOTE: Unlike the rest of
-/// instcombine, this returns a Value which should already be inserted into the
-/// function.
+/// Optimize (fcmp)|(fcmp). NOTE: Unlike the rest of instcombine, this returns
+/// a Value which should already be inserted into the function.
Value *InstCombiner::FoldOrOfFCmps(FCmpInst *LHS, FCmpInst *RHS) {
if (LHS->getPredicate() == FCmpInst::FCMP_UNO &&
RHS->getPredicate() == FCmpInst::FCMP_UNO &&
return nullptr;
}
-/// FoldOrWithConstants - This helper function folds:
+/// This helper function folds:
///
/// ((A | B) & C1) | (B & C2)
///
if (match(Op0, m_And(m_Or(m_Specific(Op1), m_Value(C)), m_Value(A))))
return BinaryOperator::CreateOr(Op1, Builder->CreateAnd(A, C));
- // (~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 (Instruction *DeMorgan = matchDeMorgansLaws(I, Builder))
+ return DeMorgan;
// Canonicalize xor to the RHS.
bool SwappedForXor = false;
// ~(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))) {
+ if (IsFreeToInvert(Op0I->getOperand(0),
+ Op0I->getOperand(0)->hasOneUse()) &&
+ IsFreeToInvert(Op0I->getOperand(1),
+ Op0I->getOperand(1)->hasOneUse())) {
Value *NotX =
Builder->CreateNot(Op0I->getOperand(0), "notlhs");
Value *NotY =
}
}
-
- if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
- if (RHS->isOne() && Op0->hasOneUse())
+ if (Constant *RHS = dyn_cast<Constant>(Op1)) {
+ if (RHS->isAllOnesValue() && Op0->hasOneUse())
// xor (cmp A, B), true = not (cmp A, B) = !cmp A, B
if (CmpInst *CI = dyn_cast<CmpInst>(Op0))
return CmpInst::Create(CI->getOpcode(),
CI->getInversePredicate(),
CI->getOperand(0), CI->getOperand(1));
+ }
+ if (ConstantInt *RHS = dyn_cast<ConstantInt>(Op1)) {
// 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))) {
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