///
/// If we can't emit an optimized form for this expression, this returns null.
///
-static Value *EvaluateGEPOffsetExpression(User *GEP, Instruction &I,
- InstCombiner &IC) {
+static Value *EvaluateGEPOffsetExpression(User *GEP, InstCombiner &IC) {
TargetData &TD = *IC.getTargetData();
gep_type_iterator GTI = gep_type_begin(GEP);
// Cast to intptrty in case a truncation occurs. If an extension is needed,
// we don't need to bother extending: the extension won't affect where the
// computation crosses zero.
- if (VariableIdx->getType()->getPrimitiveSizeInBits() > IntPtrWidth)
- VariableIdx = new TruncInst(VariableIdx,
- TD.getIntPtrType(VariableIdx->getContext()),
- VariableIdx->getName(), &I);
+ if (VariableIdx->getType()->getPrimitiveSizeInBits() > IntPtrWidth) {
+ const Type *IntPtrTy = TD.getIntPtrType(VariableIdx->getContext());
+ VariableIdx = IC.Builder->CreateTrunc(VariableIdx, IntPtrTy);
+ }
return VariableIdx;
}
// Okay, we can do this evaluation. Start by converting the index to intptr.
const Type *IntPtrTy = TD.getIntPtrType(VariableIdx->getContext());
if (VariableIdx->getType() != IntPtrTy)
- VariableIdx = CastInst::CreateIntegerCast(VariableIdx, IntPtrTy,
- true /*SExt*/,
- VariableIdx->getName(), &I);
+ VariableIdx = IC.Builder->CreateIntCast(VariableIdx, IntPtrTy,
+ true /*Signed*/);
Constant *OffsetVal = ConstantInt::get(IntPtrTy, NewOffs);
- return BinaryOperator::CreateAdd(VariableIdx, OffsetVal, "offset", &I);
+ return IC.Builder->CreateAdd(VariableIdx, OffsetVal, "offset");
}
/// FoldGEPICmp - Fold comparisons between a GEP instruction and something
// This transformation (ignoring the base and scales) is valid because we
// know pointers can't overflow since the gep is inbounds. See if we can
// output an optimized form.
- Value *Offset = EvaluateGEPOffsetExpression(GEPLHS, I, *this);
+ Value *Offset = EvaluateGEPOffsetExpression(GEPLHS, *this);
// If not, synthesize the offset the hard way.
if (Offset == 0)
if (AllZeros)
return FoldGEPICmp(GEPLHS, GEPRHS->getOperand(0), Cond, I);
+ bool GEPsInBounds = GEPLHS->isInBounds() && GEPRHS->isInBounds();
if (GEPLHS->getNumOperands() == GEPRHS->getNumOperands()) {
// If the GEPs only differ by one index, compare it.
unsigned NumDifferences = 0; // Keep track of # differences.
ConstantInt::get(Type::getInt1Ty(I.getContext()),
ICmpInst::isTrueWhenEqual(Cond)));
- else if (NumDifferences == 1) {
+ else if (NumDifferences == 1 && GEPsInBounds) {
Value *LHSV = GEPLHS->getOperand(DiffOperand);
Value *RHSV = GEPRHS->getOperand(DiffOperand);
// Make sure we do a signed comparison here.
// Only lower this if the icmp is the only user of the GEP or if we expect
// the result to fold to a constant!
if (TD &&
+ GEPsInBounds &&
(isa<ConstantExpr>(GEPLHS) || GEPLHS->hasOneUse()) &&
(isa<ConstantExpr>(GEPRHS) || GEPRHS->hasOneUse())) {
// ((gep Ptr, OFFSET1) cmp (gep Ptr, OFFSET2) ---> (OFFSET1 cmp OFFSET2)
return ReplaceInstUsesWith(ICI, ConstantInt::getTrue(X->getContext()));
// From this point on, we know that (X+C <= X) --> (X+C < X) because C != 0,
- // so the values can never be equal. Similiarly for all other "or equals"
+ // so the values can never be equal. Similarly for all other "or equals"
// operators.
// (X+1) <u X --> X >u (MAXUINT-1) --> X == 255
}
case Instruction::LShr: // (icmp pred (shr X, ShAmt), CI)
- case Instruction::AShr:
- // Only handle equality comparisons of shift-by-constant.
- if (ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1)))
- if (Instruction *Res = FoldICmpShrCst(ICI, cast<BinaryOperator>(LHSI),
- ShAmt))
+ case Instruction::AShr: {
+ // Handle equality comparisons of shift-by-constant.
+ BinaryOperator *BO = cast<BinaryOperator>(LHSI);
+ if (ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1))) {
+ if (Instruction *Res = FoldICmpShrCst(ICI, BO, ShAmt))
return Res;
+ }
+
+ // Handle exact shr's.
+ if (ICI.isEquality() && BO->isExact() && BO->hasOneUse()) {
+ if (RHSV.isMinValue())
+ return new ICmpInst(ICI.getPredicate(), BO->getOperand(0), RHS);
+ }
break;
+ }
case Instruction::SDiv:
case Instruction::UDiv:
}
}
break;
-
- case Instruction::SRem: {
- bool TrueIfSigned;
- if (LHSI->hasOneUse() &&
- isSignBitCheck(ICI.getPredicate(), RHS, TrueIfSigned)) {
- // srem has the same sign as its dividend so the divisor is irrelevant.
- return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0), RHS);
- }
- break;
- }
}
// Simplify icmp_eq and icmp_ne instructions with integer constant RHS.
if (Value *NegVal = dyn_castNegVal(BOp1))
return new ICmpInst(ICI.getPredicate(), BOp0, NegVal);
- else if (Value *NegVal = dyn_castNegVal(BOp0))
+ if (Value *NegVal = dyn_castNegVal(BOp0))
return new ICmpInst(ICI.getPredicate(), NegVal, BOp1);
- else if (BO->hasOneUse()) {
+ if (BO->hasOneUse()) {
Value *Neg = Builder->CreateNeg(BOp1);
Neg->takeName(BO);
return new ICmpInst(ICI.getPredicate(), BOp0, Neg);
// that code below can assume that Min != Max.
if (!isa<Constant>(Op0) && Op0Min == Op0Max)
return new ICmpInst(I.getPredicate(),
- ConstantInt::get(I.getContext(), Op0Min), Op1);
+ ConstantInt::get(Op0->getType(), Op0Min), Op1);
if (!isa<Constant>(Op1) && Op1Min == Op1Max)
return new ICmpInst(I.getPredicate(), Op0,
- ConstantInt::get(I.getContext(), Op1Min));
+ ConstantInt::get(Op1->getType(), Op1Min));
// Based on the range information we know about the LHS, see if we can
// simplify this comparison. For example, (x&4) < 8 is always true.
default: llvm_unreachable("Unknown icmp opcode!");
case ICmpInst::ICMP_EQ: {
if (Op0Max.ult(Op1Min) || Op0Min.ugt(Op1Max))
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType()));
// If all bits are known zero except for one, then we know at most one
// bit is set. If the comparison is against zero, then this is a check
}
case ICmpInst::ICMP_NE: {
if (Op0Max.ult(Op1Min) || Op0Min.ugt(Op1Max))
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType()));
// If all bits are known zero except for one, then we know at most one
// bit is set. If the comparison is against zero, then this is a check
}
case ICmpInst::ICMP_ULT:
if (Op0Max.ult(Op1Min)) // A <u B -> true if max(A) < min(B)
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType()));
if (Op0Min.uge(Op1Max)) // A <u B -> false if min(A) >= max(B)
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType()));
if (Op1Min == Op0Max) // A <u B -> A != B if max(A) == min(B)
return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1);
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
break;
case ICmpInst::ICMP_UGT:
if (Op0Min.ugt(Op1Max)) // A >u B -> true if min(A) > max(B)
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType()));
if (Op0Max.ule(Op1Min)) // A >u B -> false if max(A) <= max(B)
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType()));
if (Op1Max == Op0Min) // A >u B -> A != B if min(A) == max(B)
return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1);
break;
case ICmpInst::ICMP_SLT:
if (Op0Max.slt(Op1Min)) // A <s B -> true if max(A) < min(C)
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType()));
if (Op0Min.sge(Op1Max)) // A <s B -> false if min(A) >= max(C)
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType()));
if (Op1Min == Op0Max) // A <s B -> A != B if max(A) == min(B)
return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1);
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
break;
case ICmpInst::ICMP_SGT:
if (Op0Min.sgt(Op1Max)) // A >s B -> true if min(A) > max(B)
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType()));
if (Op0Max.sle(Op1Min)) // A >s B -> false if max(A) <= min(B)
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType()));
if (Op1Max == Op0Min) // A >s B -> A != B if min(A) == max(B)
return new ICmpInst(ICmpInst::ICMP_NE, Op0, Op1);
case ICmpInst::ICMP_SGE:
assert(!isa<ConstantInt>(Op1) && "ICMP_SGE with ConstantInt not folded!");
if (Op0Min.sge(Op1Max)) // A >=s B -> true if min(A) >= max(B)
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType()));
if (Op0Max.slt(Op1Min)) // A >=s B -> false if max(A) < min(B)
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType()));
break;
case ICmpInst::ICMP_SLE:
assert(!isa<ConstantInt>(Op1) && "ICMP_SLE with ConstantInt not folded!");
if (Op0Max.sle(Op1Min)) // A <=s B -> true if max(A) <= min(B)
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType()));
if (Op0Min.sgt(Op1Max)) // A <=s B -> false if min(A) > max(B)
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType()));
break;
case ICmpInst::ICMP_UGE:
assert(!isa<ConstantInt>(Op1) && "ICMP_UGE with ConstantInt not folded!");
if (Op0Min.uge(Op1Max)) // A >=u B -> true if min(A) >= max(B)
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType()));
if (Op0Max.ult(Op1Min)) // A >=u B -> false if max(A) < min(B)
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType()));
break;
case ICmpInst::ICMP_ULE:
assert(!isa<ConstantInt>(Op1) && "ICMP_ULE with ConstantInt not folded!");
if (Op0Max.ule(Op1Min)) // A <=u B -> true if max(A) <= min(B)
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType()));
if (Op0Min.ugt(Op1Max)) // A <=u B -> false if min(A) > max(B)
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType()));
break;
}
BO0->hasOneUse() && BO1->hasOneUse())
return new ICmpInst(Pred, D, B);
+ BinaryOperator *SRem = NULL;
+ // icmp (srem X, Y), Y
+ if (BO0 && BO0->getOpcode() == Instruction::SRem &&
+ Op1 == BO0->getOperand(1))
+ SRem = BO0;
+ // icmp Y, (srem X, Y)
+ else if (BO1 && BO1->getOpcode() == Instruction::SRem &&
+ Op0 == BO1->getOperand(1))
+ SRem = BO1;
+ if (SRem) {
+ // We don't check hasOneUse to avoid increasing register pressure because
+ // the value we use is the same value this instruction was already using.
+ switch (SRem == BO0 ? ICmpInst::getSwappedPredicate(Pred) : Pred) {
+ default: break;
+ case ICmpInst::ICMP_EQ:
+ return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getType()));
+ case ICmpInst::ICMP_NE:
+ return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getType()));
+ case ICmpInst::ICMP_SGT:
+ case ICmpInst::ICMP_SGE:
+ return new ICmpInst(ICmpInst::ICMP_SGT, SRem->getOperand(1),
+ Constant::getAllOnesValue(SRem->getType()));
+ case ICmpInst::ICMP_SLT:
+ case ICmpInst::ICMP_SLE:
+ return new ICmpInst(ICmpInst::ICMP_SLT, SRem->getOperand(1),
+ Constant::getNullValue(SRem->getType()));
+ }
+ }
+
if (BO0 && BO1 && BO0->getOpcode() == BO1->getOpcode() &&
BO0->hasOneUse() && BO1->hasOneUse() &&
BO0->getOperand(1) == BO1->getOperand(1)) {
}
}
break;
+ case Instruction::UDiv:
+ case Instruction::LShr:
+ if (I.isSigned())
+ break;
+ // fall-through
+ case Instruction::SDiv:
+ case Instruction::AShr:
+ if (!BO0->isExact() || !BO1->isExact())
+ break;
+ return new ICmpInst(I.getPredicate(), BO0->getOperand(0),
+ BO1->getOperand(0));
+ case Instruction::Shl: {
+ bool NUW = BO0->hasNoUnsignedWrap() && BO1->hasNoUnsignedWrap();
+ bool NSW = BO0->hasNoSignedWrap() && BO1->hasNoSignedWrap();
+ if (!NUW && !NSW)
+ break;
+ if (!NSW && I.isSigned())
+ break;
+ return new ICmpInst(I.getPredicate(), BO0->getOperand(0),
+ BO1->getOperand(0));
+ }
}
}
}
}
// (X&Z) == (Y&Z) -> (X^Y) & Z == 0
- if (Op0->hasOneUse() && Op1->hasOneUse() &&
- match(Op0, m_And(m_Value(A), m_Value(B))) &&
- match(Op1, m_And(m_Value(C), m_Value(D)))) {
+ if (match(Op0, m_OneUse(m_And(m_Value(A), m_Value(B)))) &&
+ match(Op1, m_OneUse(m_And(m_Value(C), m_Value(D))))) {
Value *X = 0, *Y = 0, *Z = 0;
if (A == C) {
return &I;
}
}
+
+ // Transform "icmp eq (trunc (lshr(X, cst1)), cst" to
+ // "icmp (and X, mask), cst"
+ uint64_t ShAmt = 0;
+ ConstantInt *Cst1;
+ if (Op0->hasOneUse() &&
+ match(Op0, m_Trunc(m_OneUse(m_LShr(m_Value(A),
+ m_ConstantInt(ShAmt))))) &&
+ match(Op1, m_ConstantInt(Cst1)) &&
+ // Only do this when A has multiple uses. This is most important to do
+ // when it exposes other optimizations.
+ !A->hasOneUse()) {
+ unsigned ASize =cast<IntegerType>(A->getType())->getPrimitiveSizeInBits();
+
+ if (ShAmt < ASize) {
+ APInt MaskV =
+ APInt::getLowBitsSet(ASize, Op0->getType()->getPrimitiveSizeInBits());
+ MaskV <<= ShAmt;
+
+ APInt CmpV = Cst1->getValue().zext(ASize);
+ CmpV <<= ShAmt;
+
+ Value *Mask = Builder->CreateAnd(A, Builder->getInt(MaskV));
+ return new ICmpInst(I.getPredicate(), Mask, Builder->getInt(CmpV));
+ }
+ }
}
{
if (Constant *RHSC = dyn_cast<Constant>(Op1)) {
if (Instruction *LHSI = dyn_cast<Instruction>(Op0))
switch (LHSI->getOpcode()) {
+ case Instruction::FPExt: {
+ // fcmp (fpext x), C -> fcmp x, (fptrunc C) if fptrunc is lossless
+ FPExtInst *LHSExt = cast<FPExtInst>(LHSI);
+ ConstantFP *RHSF = dyn_cast<ConstantFP>(RHSC);
+ if (!RHSF)
+ break;
+
+ // We can't convert a PPC double double.
+ if (RHSF->getType()->isPPC_FP128Ty())
+ break;
+
+ const fltSemantics *Sem;
+ // FIXME: This shouldn't be here.
+ if (LHSExt->getSrcTy()->isFloatTy())
+ Sem = &APFloat::IEEEsingle;
+ else if (LHSExt->getSrcTy()->isDoubleTy())
+ Sem = &APFloat::IEEEdouble;
+ else if (LHSExt->getSrcTy()->isFP128Ty())
+ Sem = &APFloat::IEEEquad;
+ else if (LHSExt->getSrcTy()->isX86_FP80Ty())
+ Sem = &APFloat::x87DoubleExtended;
+ else
+ break;
+
+ bool Lossy;
+ APFloat F = RHSF->getValueAPF();
+ F.convert(*Sem, APFloat::rmNearestTiesToEven, &Lossy);
+
+ // Avoid lossy conversions and denormals.
+ if (!Lossy &&
+ F.compare(APFloat::getSmallestNormalized(*Sem)) !=
+ APFloat::cmpLessThan)
+ return new FCmpInst(I.getPredicate(), LHSExt->getOperand(0),
+ ConstantFP::get(RHSC->getContext(), F));
+ break;
+ }
case Instruction::PHI:
// Only fold fcmp into the PHI if the phi and fcmp are in the same
// block. If in the same block, we're encouraging jump threading. If
return SelectInst::Create(LHSI->getOperand(0), Op1, Op2);
break;
}
+ case Instruction::FSub: {
+ // fcmp pred (fneg x), C -> fcmp swap(pred) x, -C
+ Value *Op;
+ if (match(LHSI, m_FNeg(m_Value(Op))))
+ return new FCmpInst(I.getSwappedPredicate(), Op,
+ ConstantExpr::getFNeg(RHSC));
+ break;
+ }
case Instruction::Load:
if (GetElementPtrInst *GEP =
dyn_cast<GetElementPtrInst>(LHSI->getOperand(0))) {
}
}
+ // fcmp pred (fneg x), (fneg y) -> fcmp swap(pred) x, y
+ Value *X, *Y;
+ if (match(Op0, m_FNeg(m_Value(X))) && match(Op1, m_FNeg(m_Value(Y))))
+ return new FCmpInst(I.getSwappedPredicate(), X, Y);
+
+ // fcmp (fpext x), (fpext y) -> fcmp x, y
+ if (FPExtInst *LHSExt = dyn_cast<FPExtInst>(Op0))
+ if (FPExtInst *RHSExt = dyn_cast<FPExtInst>(Op1))
+ if (LHSExt->getSrcTy() == RHSExt->getSrcTy())
+ return new FCmpInst(I.getPredicate(), LHSExt->getOperand(0),
+ RHSExt->getOperand(0));
+
return Changed ? &I : 0;
}