#include "InstCombine.h"
#include "llvm/Intrinsics.h"
#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Support/ConstantRange.h"
#include "llvm/Support/PatternMatch.h"
using namespace llvm;
using namespace PatternMatch;
case 4: Pred = isordered ? FCmpInst::FCMP_OLT : FCmpInst::FCMP_ULT; break;
case 5: Pred = isordered ? FCmpInst::FCMP_ONE : FCmpInst::FCMP_UNE; break;
case 6: Pred = isordered ? FCmpInst::FCMP_OLE : FCmpInst::FCMP_ULE; break;
- case 7: return ConstantInt::getTrue(LHS->getContext());
+ case 7:
+ if (!isordered) return ConstantInt::getTrue(LHS->getContext());
+ Pred = FCmpInst::FCMP_ORD; break;
}
return Builder->CreateFCmp(Pred, LHS, RHS);
}
}
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);
+ if (Op->hasOneUse()){
+ if (Together != OpRHS) {
+ // (X | C1) & C2 --> (X | (C1&C2)) & C2
+ Value *Or = Builder->CreateOr(X, Together);
+ Or->takeName(Op);
+ return BinaryOperator::CreateAnd(Or, AndRHS);
+ }
+
+ ConstantInt *TogetherCI = dyn_cast<ConstantInt>(Together);
+ if (TogetherCI && !TogetherCI->isZero()){
+ // (X | C1) & C2 --> (X & (C2^(C1&C2))) | C1
+ // NOTE: This reduces the number of bits set in the & mask, which
+ // can expose opportunities for store narrowing.
+ Together = ConstantExpr::getXor(AndRHS, Together);
+ Value *And = Builder->CreateAnd(X, Together);
+ And->takeName(Op);
+ return BinaryOperator::CreateOr(And, OpRHS);
+ }
}
+
break;
case Instruction::Add:
if (Op->hasOneUse()) {
ConstantInt *CI = ConstantInt::get(AndRHS->getContext(),
AndRHS->getValue() & ShlMask);
- if (CI->getValue() == ShlMask) {
- // Masking out bits that the shift already masks
+ 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.
+
+ if (CI != AndRHS) { // Reducing bits set in and.
TheAnd.setOperand(1, CI);
return &TheAnd;
}
ConstantInt *CI = ConstantInt::get(Op->getContext(),
AndRHS->getValue() & ShrMask);
- if (CI->getValue() == ShrMask) {
- // Masking out bits that the shift already masks.
+ if (CI->getValue() == ShrMask)
+ // Masking out bits that the shift already masks.
return ReplaceInstUsesWith(TheAnd, Op);
- } else if (CI != AndRHS) {
+
+ if (CI != AndRHS) {
TheAnd.setOperand(1, CI); // Reduce bits set in and cst.
return &TheAnd;
}
/// 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
+/// true, otherwise (V < Lo || V >= Hi). In practice, 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.
return Builder->CreateAdd(LHSI->getOperand(0), RHS, "fold");
}
+/// enum for classifying (icmp eq (A & B), C) and (icmp ne (A & B), C)
+/// One of A and B is considered the mask, the other the value. This is
+/// described as the "AMask" or "BMask" part of the enum. If the enum
+/// contains only "Mask", then both A and B can be considered masks.
+/// If A is the mask, then it was proven, that (A & C) == C. This
+/// is trivial if C == A, or C == 0. If both A and C are constants, this
+/// proof is also easy.
+/// For the following explanations we assume that A is the mask.
+/// The part "AllOnes" declares, that the comparison is true only
+/// if (A & B) == A, or all bits of A are set in B.
+/// Example: (icmp eq (A & 3), 3) -> FoldMskICmp_AMask_AllOnes
+/// The part "AllZeroes" declares, that the comparison is true only
+/// if (A & B) == 0, or all bits of A are cleared in B.
+/// Example: (icmp eq (A & 3), 0) -> FoldMskICmp_Mask_AllZeroes
+/// The part "Mixed" declares, that (A & B) == C and C might or might not
+/// contain any number of one bits and zero bits.
+/// Example: (icmp eq (A & 3), 1) -> FoldMskICmp_AMask_Mixed
+/// The Part "Not" means, that in above descriptions "==" should be replaced
+/// by "!=".
+/// Example: (icmp ne (A & 3), 3) -> FoldMskICmp_AMask_NotAllOnes
+/// If the mask A contains a single bit, then the following is equivalent:
+/// (icmp eq (A & B), A) equals (icmp ne (A & B), 0)
+/// (icmp ne (A & B), A) equals (icmp eq (A & B), 0)
+enum MaskedICmpType {
+ FoldMskICmp_AMask_AllOnes = 1,
+ FoldMskICmp_AMask_NotAllOnes = 2,
+ FoldMskICmp_BMask_AllOnes = 4,
+ FoldMskICmp_BMask_NotAllOnes = 8,
+ FoldMskICmp_Mask_AllZeroes = 16,
+ FoldMskICmp_Mask_NotAllZeroes = 32,
+ FoldMskICmp_AMask_Mixed = 64,
+ FoldMskICmp_AMask_NotMixed = 128,
+ FoldMskICmp_BMask_Mixed = 256,
+ FoldMskICmp_BMask_NotMixed = 512
+};
+
+/// 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)
+{
+ ConstantInt *ACst = dyn_cast<ConstantInt>(A);
+ ConstantInt *BCst = dyn_cast<ConstantInt>(B);
+ ConstantInt *CCst = dyn_cast<ConstantInt>(C);
+ bool icmp_eq = (SCC == ICmpInst::ICMP_EQ);
+ bool icmp_abit = (ACst != 0 && !ACst->isZero() &&
+ ACst->getValue().isPowerOf2());
+ bool icmp_bbit = (BCst != 0 && !BCst->isZero() &&
+ BCst->getValue().isPowerOf2());
+ unsigned result = 0;
+ if (CCst != 0 && CCst->isZero()) {
+ // if C is zero, then both A and B qualify as mask
+ result |= (icmp_eq ? (FoldMskICmp_Mask_AllZeroes |
+ FoldMskICmp_Mask_AllZeroes |
+ FoldMskICmp_AMask_Mixed |
+ FoldMskICmp_BMask_Mixed)
+ : (FoldMskICmp_Mask_NotAllZeroes |
+ FoldMskICmp_Mask_NotAllZeroes |
+ FoldMskICmp_AMask_NotMixed |
+ FoldMskICmp_BMask_NotMixed));
+ if (icmp_abit)
+ result |= (icmp_eq ? (FoldMskICmp_AMask_NotAllOnes |
+ FoldMskICmp_AMask_NotMixed)
+ : (FoldMskICmp_AMask_AllOnes |
+ FoldMskICmp_AMask_Mixed));
+ if (icmp_bbit)
+ result |= (icmp_eq ? (FoldMskICmp_BMask_NotAllOnes |
+ FoldMskICmp_BMask_NotMixed)
+ : (FoldMskICmp_BMask_AllOnes |
+ FoldMskICmp_BMask_Mixed));
+ return result;
+ }
+ if (A == C) {
+ result |= (icmp_eq ? (FoldMskICmp_AMask_AllOnes |
+ FoldMskICmp_AMask_Mixed)
+ : (FoldMskICmp_AMask_NotAllOnes |
+ FoldMskICmp_AMask_NotMixed));
+ if (icmp_abit)
+ result |= (icmp_eq ? (FoldMskICmp_Mask_NotAllZeroes |
+ FoldMskICmp_AMask_NotMixed)
+ : (FoldMskICmp_Mask_AllZeroes |
+ FoldMskICmp_AMask_Mixed));
+ }
+ else if (ACst != 0 && CCst != 0 &&
+ ConstantExpr::getAnd(ACst, CCst) == CCst) {
+ result |= (icmp_eq ? FoldMskICmp_AMask_Mixed
+ : FoldMskICmp_AMask_NotMixed);
+ }
+ if (B == C)
+ {
+ result |= (icmp_eq ? (FoldMskICmp_BMask_AllOnes |
+ FoldMskICmp_BMask_Mixed)
+ : (FoldMskICmp_BMask_NotAllOnes |
+ FoldMskICmp_BMask_NotMixed));
+ if (icmp_bbit)
+ result |= (icmp_eq ? (FoldMskICmp_Mask_NotAllZeroes |
+ FoldMskICmp_BMask_NotMixed)
+ : (FoldMskICmp_Mask_AllZeroes |
+ FoldMskICmp_BMask_Mixed));
+ }
+ else if (BCst != 0 && CCst != 0 &&
+ ConstantExpr::getAnd(BCst, CCst) == CCst) {
+ result |= (icmp_eq ? FoldMskICmp_BMask_Mixed
+ : FoldMskICmp_BMask_NotMixed);
+ }
+ return result;
+}
+
+/// foldLogOpOfMaskedICmpsHelper:
+/// 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,
+ ICmpInst *LHS, ICmpInst *RHS) {
+ ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
+ if (LHSCC != ICmpInst::ICMP_EQ && LHSCC != ICmpInst::ICMP_NE) return 0;
+ if (RHSCC != ICmpInst::ICMP_EQ && RHSCC != ICmpInst::ICMP_NE) return 0;
+ if (LHS->getOperand(0)->getType() != RHS->getOperand(0)->getType()) return 0;
+ // vectors are not (yet?) supported
+ if (LHS->getOperand(0)->getType()->isVectorTy()) return 0;
+
+ // Here comes the tricky part:
+ // LHS might be of the form L11 & L12 == X, X == L21 & L22,
+ // and L11 & L12 == L21 & L22. The same goes for RHS.
+ // Now we must find those components L** and R**, that are equal, so
+ // that we can extract the parameters A, B, C, D, and E for the canonical
+ // above.
+ Value *L1 = LHS->getOperand(0);
+ Value *L2 = LHS->getOperand(1);
+ Value *L11,*L12,*L21,*L22;
+ if (match(L1, m_And(m_Value(L11), m_Value(L12)))) {
+ if (!match(L2, m_And(m_Value(L21), m_Value(L22))))
+ L21 = L22 = 0;
+ }
+ else {
+ if (!match(L2, m_And(m_Value(L11), m_Value(L12))))
+ return 0;
+ std::swap(L1, L2);
+ L21 = L22 = 0;
+ }
+
+ Value *R1 = RHS->getOperand(0);
+ Value *R2 = RHS->getOperand(1);
+ Value *R11,*R12;
+ bool ok = false;
+ if (match(R1, m_And(m_Value(R11), m_Value(R12)))) {
+ if (R11 != 0 && (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22)) {
+ A = R11; D = R12; E = R2; ok = true;
+ }
+ else
+ if (R12 != 0 && (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22)) {
+ A = R12; D = R11; E = R2; ok = true;
+ }
+ }
+ if (!ok && match(R2, m_And(m_Value(R11), m_Value(R12)))) {
+ if (R11 != 0 && (R11 == L11 || R11 == L12 || R11 == L21 || R11 == L22)) {
+ A = R11; D = R12; E = R1; ok = true;
+ }
+ else
+ if (R12 != 0 && (R12 == L11 || R12 == L12 || R12 == L21 || R12 == L22)) {
+ A = R12; D = R11; E = R1; ok = true;
+ }
+ else
+ return 0;
+ }
+ if (!ok)
+ return 0;
+
+ if (L11 == A) {
+ B = L12; C = L2;
+ }
+ else if (L12 == A) {
+ B = L11; C = L2;
+ }
+ else if (L21 == A) {
+ B = L22; C = L1;
+ }
+ else if (L22 == A) {
+ B = L21; C = L1;
+ }
+
+ unsigned left_type = getTypeOfMaskedICmp(A, B, C, LHSCC);
+ 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)
+static Value* foldLogOpOfMaskedICmps(ICmpInst *LHS, ICmpInst *RHS,
+ ICmpInst::Predicate NEWCC,
+ llvm::InstCombiner::BuilderTy* Builder) {
+ Value *A = 0, *B = 0, *C = 0, *D = 0, *E = 0;
+ unsigned mask = foldLogOpOfMaskedICmpsHelper(A, B, C, D, E, LHS, RHS);
+ if (mask == 0) return 0;
+
+ if (NEWCC == ICmpInst::ICMP_NE)
+ mask >>= 1; // treat "Not"-states as normal states
+
+ if (mask & FoldMskICmp_Mask_AllZeroes) {
+ // (icmp eq (A & B), 0) & (icmp eq (A & D), 0)
+ // -> (icmp eq (A & (B|D)), 0)
+ Value* newOr = Builder->CreateOr(B, D);
+ Value* newAnd = Builder->CreateAnd(A, newOr);
+ // we can't use C as zero, because we might actually handle
+ // (icmp ne (A & B), B) & (icmp ne (A & D), D)
+ // with B and D, having a single bit set
+ Value* zero = Constant::getNullValue(A->getType());
+ return Builder->CreateICmp(NEWCC, newAnd, zero);
+ }
+ else if (mask & FoldMskICmp_BMask_AllOnes) {
+ // (icmp eq (A & B), B) & (icmp eq (A & D), D)
+ // -> (icmp eq (A & (B|D)), (B|D))
+ Value* newOr = Builder->CreateOr(B, D);
+ Value* newAnd = Builder->CreateAnd(A, newOr);
+ return Builder->CreateICmp(NEWCC, newAnd, newOr);
+ }
+ else if (mask & FoldMskICmp_AMask_AllOnes) {
+ // (icmp eq (A & B), A) & (icmp eq (A & D), A)
+ // -> (icmp eq (A & (B&D)), A)
+ Value* newAnd1 = Builder->CreateAnd(B, D);
+ Value* newAnd = Builder->CreateAnd(A, newAnd1);
+ return Builder->CreateICmp(NEWCC, newAnd, A);
+ }
+ else if (mask & FoldMskICmp_BMask_Mixed) {
+ // (icmp eq (A & B), C) & (icmp eq (A & D), E)
+ // We already know that B & C == C && D & E == E.
+ // If we can prove that (B & D) & (C ^ E) == 0, that is, the bits of
+ // C and E, which are shared by both the mask B and the mask D, don't
+ // contradict, then we can transform to
+ // -> (icmp eq (A & (B|D)), (C|E))
+ // Currently, we only handle the case of B, C, D, and E being constant.
+ ConstantInt *BCst = dyn_cast<ConstantInt>(B);
+ if (BCst == 0) return 0;
+ ConstantInt *DCst = dyn_cast<ConstantInt>(D);
+ if (DCst == 0) return 0;
+ // we can't simply use C and E, because we might actually handle
+ // (icmp ne (A & B), B) & (icmp eq (A & D), D)
+ // with B and D, having a single bit set
+
+ ConstantInt *CCst = dyn_cast<ConstantInt>(C);
+ if (CCst == 0) return 0;
+ if (LHS->getPredicate() != NEWCC)
+ CCst = dyn_cast<ConstantInt>( ConstantExpr::getXor(BCst, CCst) );
+ ConstantInt *ECst = dyn_cast<ConstantInt>(E);
+ if (ECst == 0) return 0;
+ if (RHS->getPredicate() != NEWCC)
+ ECst = dyn_cast<ConstantInt>( ConstantExpr::getXor(DCst, ECst) );
+ ConstantInt* MCst = dyn_cast<ConstantInt>(
+ ConstantExpr::getAnd(ConstantExpr::getAnd(BCst, DCst),
+ ConstantExpr::getXor(CCst, ECst)) );
+ // if there is a conflict we should actually return a false for the
+ // whole construct
+ if (!MCst->isZero())
+ return 0;
+ Value *newOr1 = Builder->CreateOr(B, D);
+ Value *newOr2 = ConstantExpr::getOr(CCst, ECst);
+ Value *newAnd = Builder->CreateAnd(A, newOr1);
+ return Builder->CreateICmp(NEWCC, newAnd, newOr2);
+ }
+ return 0;
+}
+
/// FoldAndOfICmps - Fold (icmp)&(icmp) if possible.
Value *InstCombiner::FoldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS) {
ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate();
return getICmpValue(isSigned, Code, Op0, Op1, Builder);
}
}
+
+ // handle (roughly): (icmp eq (A & B), C) & (icmp eq (A & D), E)
+ if (Value *V = foldLogOpOfMaskedICmps(LHS, RHS, ICmpInst::ICMP_EQ, Builder))
+ return V;
// This only handles icmp of constants: (icmp1 A, C1) & (icmp2 B, C2).
Value *Val = LHS->getOperand(0), *Val2 = RHS->getOperand(0);
Value *NewOr = Builder->CreateOr(Val, Val2);
return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
}
+
+ // (icmp slt A, 0) & (icmp slt B, 0) --> (icmp slt (A&B), 0)
+ if (LHSCC == ICmpInst::ICMP_SLT && LHSCst->isZero()) {
+ Value *NewAnd = Builder->CreateAnd(Val, Val2);
+ return Builder->CreateICmp(LHSCC, NewAnd, LHSCst);
+ }
+
+ // (icmp sgt A, -1) & (icmp sgt B, -1) --> (icmp sgt (A|B), -1)
+ if (LHSCC == ICmpInst::ICMP_SGT && LHSCst->isAllOnesValue()) {
+ Value *NewOr = Builder->CreateOr(Val, Val2);
+ return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
+ }
+ }
+
+ // (trunc x) == C1 & (and x, CA) == C2 -> (and x, CA|CMAX) == C1|C2
+ // where CMAX is the all ones value for the truncated type,
+ // iff the lower bits of C2 and CA are zero.
+ if (LHSCC == RHSCC && ICmpInst::isEquality(LHSCC) &&
+ LHS->hasOneUse() && RHS->hasOneUse()) {
+ Value *V;
+ ConstantInt *AndCst, *SmallCst = 0, *BigCst = 0;
+
+ // (trunc x) == C1 & (and x, CA) == C2
+ if (match(Val2, m_Trunc(m_Value(V))) &&
+ match(Val, m_And(m_Specific(V), m_ConstantInt(AndCst)))) {
+ SmallCst = RHSCst;
+ BigCst = LHSCst;
+ }
+ // (and x, CA) == C2 & (trunc x) == C1
+ else if (match(Val, m_Trunc(m_Value(V))) &&
+ match(Val2, m_And(m_Specific(V), m_ConstantInt(AndCst)))) {
+ SmallCst = LHSCst;
+ BigCst = RHSCst;
+ }
+
+ if (SmallCst && BigCst) {
+ unsigned BigBitSize = BigCst->getType()->getBitWidth();
+ unsigned SmallBitSize = SmallCst->getType()->getBitWidth();
+
+ // Check that the low bits are zero.
+ APInt Low = APInt::getLowBitsSet(BigBitSize, SmallBitSize);
+ if ((Low & AndCst->getValue()) == 0 && (Low & BigCst->getValue()) == 0) {
+ Value *NewAnd = Builder->CreateAnd(V, Low | AndCst->getValue());
+ APInt N = SmallCst->getValue().zext(BigBitSize) | BigCst->getValue();
+ Value *NewVal = ConstantInt::get(AndCst->getType()->getContext(), N);
+ return Builder->CreateICmp(LHSCC, NewAnd, NewVal);
+ }
+ }
}
// From here on, we only handle:
LHSCC == ICmpInst::ICMP_SGE || LHSCC == ICmpInst::ICMP_SLE ||
RHSCC == ICmpInst::ICMP_SGE || RHSCC == ICmpInst::ICMP_SLE)
return 0;
-
+
+ // 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 RHSRange =
+ ConstantRange::makeICmpRegion(RHSCC, RHSCst->getValue());
+
+ if (LHSRange.intersectWith(RHSRange).isEmptySet())
+ return ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
+
// We can't fold (ugt x, C) & (sgt x, C2).
if (!PredicatesFoldable(LHSCC, RHSCC))
return 0;
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 ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
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
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 ConstantInt::get(CmpInst::makeCmpResultType(LHS->getType()), 0);
case ICmpInst::ICMP_UGT: // (X s< 13 & X u> 15) -> no change
break;
case ICmpInst::ICMP_NE: // (X s< 13 & X != 15) -> X < 13
Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
- bool Changed = SimplifyCommutative(I);
+ bool Changed = SimplifyAssociativeOrCommutative(I);
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
if (Value *V = SimplifyAndInst(Op0, Op1, TD))
return ReplaceInstUsesWith(I, V);
+ // (A|B)&(A|C) -> A|(B&C) etc
+ if (Value *V = SimplifyUsingDistributiveLaws(I))
+ 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))
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)) {
switch (Op0I->getOpcode()) {
default: break;
case Instruction::Xor:
- case Instruction::Or:
+ case Instruction::Or: {
// If the mask is only needed on one incoming arm, push it up.
if (!Op0I->hasOneUse()) break;
+ APInt NotAndRHS(~AndRHSMask);
if (MaskedValueIsZero(Op0LHS, NotAndRHS)) {
// Not masking anything out for the LHS, move to RHS.
Value *NewRHS = Builder->CreateAnd(Op0RHS, AndRHS,
}
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) & 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()) {
+ if (Op0I->hasOneUse() && !match(Op0LHS, m_Zero())) {
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)) {
+ if (MaskedValueIsZero(Op0LHS, Mask)) {
Value *NewNeg = Builder->CreateNeg(Op0RHS);
return BinaryOperator::CreateAnd(NewNeg, AndRHS);
}
}
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);
- }
- }
+ }
+
+ // If this is an integer truncation, and if the source is an 'and' with
+ // immediate, transform it. This frequently occurs for bitfield accesses.
+ {
+ Value *X = 0; ConstantInt *YC = 0;
+ if (match(Op0, m_Trunc(m_And(m_Value(X), m_ConstantInt(YC))))) {
+ // Change: and (trunc (and X, YC) to T), C2
+ // into : and (trunc X to T), trunc(YC) & C2
+ // This will fold the two constants together, which may allow
+ // other simplifications.
+ Value *NewCast = Builder->CreateTrunc(X, I.getType(), "and.shrunk");
+ Constant *C3 = ConstantExpr::getTrunc(YC, I.getType());
+ C3 = ConstantExpr::getAnd(C3, AndRHS);
+ return BinaryOperator::CreateAnd(NewCast, C3);
}
}
I.getName()+".demorgan");
return BinaryOperator::CreateNot(Or);
}
-
+
{
Value *A = 0, *B = 0, *C = 0, *D = 0;
// (A|B) & ~(A&B) -> A^B
cast<BinaryOperator>(Op1)->swapOperands();
std::swap(A, B);
}
- if (A == Op0) // A&(A^B) -> A & ~B
+ // Notice that the patten (A&(~B)) is actually (A&(-1^B)), so if
+ // A is originally -1 (or a vector of -1 and undefs), then we enter
+ // an endless loop. By checking that A is non-constant we ensure that
+ // we will never get to the loop.
+ if (A == Op0 && !isa<Constant>(A)) // A&(A^B) -> A & ~B
return BinaryOperator::CreateAnd(A, Builder->CreateNot(B, "tmp"));
}
/// 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());
+ IntegerType *ITy = dyn_cast<IntegerType>(I.getType());
if (!ITy || ITy->getBitWidth() % 16 ||
// ByteMask only allows up to 32-byte values.
ITy->getBitWidth() > 32*8)
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);
+ Function *F = Intrinsic::getDeclaration(M, Intrinsic::bswap, ITy);
return CallInst::Create(F, V);
}
return getICmpValue(isSigned, Code, Op0, Op1, Builder);
}
}
-
+
+ // handle (roughly):
+ // (icmp ne (A & B), C) | (icmp ne (A & D), E)
+ if (Value *V = foldLogOpOfMaskedICmps(LHS, RHS, ICmpInst::ICMP_NE, Builder))
+ return V;
+
// 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 Builder->CreateICmp(LHSCC, NewOr, LHSCst);
+ if (LHSCst == RHSCst && LHSCC == RHSCC) {
+ // (icmp ne A, 0) | (icmp ne B, 0) --> (icmp ne (A|B), 0)
+ if (LHSCC == ICmpInst::ICMP_NE && LHSCst->isZero()) {
+ Value *NewOr = Builder->CreateOr(Val, Val2);
+ return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
+ }
+
+ // (icmp slt A, 0) | (icmp slt B, 0) --> (icmp slt (A|B), 0)
+ if (LHSCC == ICmpInst::ICMP_SLT && LHSCst->isZero()) {
+ Value *NewOr = Builder->CreateOr(Val, Val2);
+ return Builder->CreateICmp(LHSCC, NewOr, LHSCst);
+ }
+
+ // (icmp sgt A, -1) | (icmp sgt B, -1) --> (icmp sgt (A&B), -1)
+ if (LHSCC == ICmpInst::ICMP_SGT && LHSCst->isAllOnesValue()) {
+ Value *NewAnd = Builder->CreateAnd(Val, Val2);
+ return Builder->CreateICmp(LHSCC, NewAnd, LHSCst);
+ }
}
-
+
+ // (icmp ult (X + CA), C1) | (icmp eq X, C2) -> (icmp ule (X + CA), C1)
+ // iff C2 + CA == C1.
+ if (LHSCC == ICmpInst::ICMP_ULT && RHSCC == ICmpInst::ICMP_EQ) {
+ ConstantInt *AddCst;
+ if (match(Val, m_Add(m_Specific(Val2), m_ConstantInt(AddCst))))
+ if (RHSCst->getValue() + AddCst->getValue() == LHSCst->getValue())
+ return Builder->CreateICmpULE(Val, LHSCst);
+ }
+
// From here on, we only handle:
// (icmp1 A, C1) | (icmp2 A, C2) --> something simpler.
if (Val != Val2) return 0;
}
Instruction *InstCombiner::visitOr(BinaryOperator &I) {
- bool Changed = SimplifyCommutative(I);
+ bool Changed = SimplifyAssociativeOrCommutative(I);
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
if (Value *V = SimplifyOrInst(Op0, Op1, TD))
return ReplaceInstUsesWith(I, V);
+ // (A&B)|(A&C) -> A&(B|C) etc
+ if (Value *V = SimplifyUsingDistributiveLaws(I))
+ 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))
// (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())))) {
+ (match(Op0, m_LogicalShift(m_Value(), m_Value())) &&
+ match(Op1, m_LogicalShift(m_Value(), m_Value())))) {
if (Instruction *BSwap = MatchBSwap(I))
return BSwap;
}
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;
+ Value *V1 = 0, *V2 = 0;
C1 = dyn_cast<ConstantInt>(C);
C2 = dyn_cast<ConstantInt>(D);
if (C1 && C2) { // (A & C1)|(B & C2)
}
}
}
-
- // 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.
// Don't do this for vector select idioms, the code generator doesn't handle
return BinaryOperator::CreateNot(And);
}
+ // Canonicalize xor to the RHS.
+ if (match(Op0, m_Xor(m_Value(), m_Value())))
+ std::swap(Op0, Op1);
+
+ // A | ( A ^ B) -> A | B
+ // A | (~A ^ B) -> A | ~B
+ if (match(Op1, m_Xor(m_Value(A), m_Value(B)))) {
+ if (Op0 == A || Op0 == B)
+ return BinaryOperator::CreateOr(A, B);
+
+ if (Op1->hasOneUse() && match(A, m_Not(m_Specific(Op0)))) {
+ Value *Not = Builder->CreateNot(B, B->getName()+".not");
+ return BinaryOperator::CreateOr(Not, Op0);
+ }
+ if (Op1->hasOneUse() && match(B, m_Not(m_Specific(Op0)))) {
+ Value *Not = Builder->CreateNot(A, A->getName()+".not");
+ return BinaryOperator::CreateOr(Not, Op0);
+ }
+ }
+
+ // A | ~(A | B) -> A | ~B
+ // A | ~(A ^ B) -> A | ~B
+ if (match(Op1, m_Not(m_Value(A))))
+ if (BinaryOperator *B = dyn_cast<BinaryOperator>(A))
+ if ((Op0 == B->getOperand(0) || Op0 == B->getOperand(1)) &&
+ Op1->hasOneUse() && (B->getOpcode() == Instruction::Or ||
+ B->getOpcode() == Instruction::Xor)) {
+ Value *NotOp = Op0 == B->getOperand(0) ? B->getOperand(1) :
+ B->getOperand(0);
+ Value *Not = Builder->CreateNot(NotOp, NotOp->getName()+".not");
+ return BinaryOperator::CreateOr(Not, Op0);
+ }
+
if (ICmpInst *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
if (ICmpInst *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
if (Value *Res = FoldOrOfICmps(LHS, RHS))
// 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 ?
- const Type *SrcTy = Op0C->getOperand(0)->getType();
- if (SrcTy == Op1C->getOperand(0)->getType() &&
- SrcTy->isIntOrIntVectorTy()) {
- Value *Op0COp = Op0C->getOperand(0), *Op1COp = Op1C->getOperand(0);
-
- if ((!isa<ICmpInst>(Op0COp) || !isa<ICmpInst>(Op1COp)) &&
- // Only do this if the casts both really cause code to be
- // generated.
- ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) &&
- ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) {
- Value *NewOp = Builder->CreateOr(Op0COp, Op1COp, I.getName());
- return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
- }
-
- // If this is or(cast(icmp), cast(icmp)), try to fold this even if the
- // cast is otherwise not optimizable. This happens for vector sexts.
- if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1COp))
- if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0COp))
- if (Value *Res = FoldOrOfICmps(LHS, RHS))
- return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
-
- // If this is or(cast(fcmp), cast(fcmp)), try to fold this even if the
- // cast is otherwise not optimizable. This happens for vector sexts.
- if (FCmpInst *RHS = dyn_cast<FCmpInst>(Op1COp))
- if (FCmpInst *LHS = dyn_cast<FCmpInst>(Op0COp))
- if (Value *Res = FoldOrOfFCmps(LHS, RHS))
- return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
+ CastInst *Op1C = dyn_cast<CastInst>(Op1);
+ if (Op1C && Op0C->getOpcode() == Op1C->getOpcode()) {// same cast kind ?
+ const Type *SrcTy = Op0C->getOperand(0)->getType();
+ if (SrcTy == Op1C->getOperand(0)->getType() &&
+ SrcTy->isIntOrIntVectorTy()) {
+ Value *Op0COp = Op0C->getOperand(0), *Op1COp = Op1C->getOperand(0);
+
+ if ((!isa<ICmpInst>(Op0COp) || !isa<ICmpInst>(Op1COp)) &&
+ // Only do this if the casts both really cause code to be
+ // generated.
+ ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) &&
+ ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) {
+ Value *NewOp = Builder->CreateOr(Op0COp, Op1COp, I.getName());
+ return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
}
+
+ // If this is or(cast(icmp), cast(icmp)), try to fold this even if the
+ // cast is otherwise not optimizable. This happens for vector sexts.
+ if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1COp))
+ if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0COp))
+ if (Value *Res = FoldOrOfICmps(LHS, RHS))
+ return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
+
+ // If this is or(cast(fcmp), cast(fcmp)), try to fold this even if the
+ // cast is otherwise not optimizable. This happens for vector sexts.
+ if (FCmpInst *RHS = dyn_cast<FCmpInst>(Op1COp))
+ if (FCmpInst *LHS = dyn_cast<FCmpInst>(Op0COp))
+ if (Value *Res = FoldOrOfFCmps(LHS, RHS))
+ return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
}
+ }
+ }
+
+ // or(sext(A), B) -> A ? -1 : B where A is an i1
+ // or(A, sext(B)) -> B ? -1 : A where B is an i1
+ if (match(Op0, m_SExt(m_Value(A))) && A->getType()->isIntegerTy(1))
+ return SelectInst::Create(A, ConstantInt::getSigned(I.getType(), -1), Op1);
+ if (match(Op1, m_SExt(m_Value(A))) && A->getType()->isIntegerTy(1))
+ return SelectInst::Create(A, ConstantInt::getSigned(I.getType(), -1), Op0);
+
+ // Note: If we've gotten to the point of visiting the outer OR, then the
+ // inner one couldn't be simplified. If it was a constant, then it won't
+ // be simplified by a later pass either, so we try swapping the inner/outer
+ // ORs in the hopes that we'll be able to simplify it this way.
+ // (X|C) | V --> (X|V) | C
+ if (Op0->hasOneUse() && !isa<ConstantInt>(Op1) &&
+ match(Op0, m_Or(m_Value(A), m_ConstantInt(C1)))) {
+ Value *Inner = Builder->CreateOr(A, Op1);
+ Inner->takeName(Op0);
+ return BinaryOperator::CreateOr(Inner, C1);
}
return Changed ? &I : 0;
}
Instruction *InstCombiner::visitXor(BinaryOperator &I) {
- bool Changed = SimplifyCommutative(I);
+ bool Changed = SimplifyAssociativeOrCommutative(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
- }
+ if (Value *V = SimplifyXorInst(Op0, Op1, TD))
+ return ReplaceInstUsesWith(I, V);
+
+ // (A&B)^(A&C) -> A&(B^C) etc
+ if (Value *V = SimplifyUsingDistributiveLaws(I))
+ return ReplaceInstUsesWith(I, V);
- // 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 (I.getType()->isVectorTy())
- if (isa<ConstantAggregateZero>(Op1))
- return ReplaceInstUsesWith(I, Op0); // X ^ <0,0> -> X
// Is this a ~ operation?
if (Value *NotOp = dyn_castNotVal(&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;
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)
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
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)))
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