//===----------------------------------------------------------------------===//
#include "InstCombine.h"
-#include "llvm/IntrinsicInst.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/MemoryBuiltins.h"
-#include "llvm/Target/TargetData.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/IntrinsicInst.h"
#include "llvm/Support/ConstantRange.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/PatternMatch.h"
+#include "llvm/Target/TargetLibraryInfo.h"
using namespace llvm;
using namespace PatternMatch;
}
}
+/// Returns true if the exploded icmp can be expressed as a signed comparison
+/// to zero and updates the predicate accordingly.
+/// The signedness of the comparison is preserved.
+static bool isSignTest(ICmpInst::Predicate &pred, const ConstantInt *RHS) {
+ if (!ICmpInst::isSigned(pred))
+ return false;
+
+ if (RHS->isZero())
+ return ICmpInst::isRelational(pred);
+
+ if (RHS->isOne()) {
+ if (pred == ICmpInst::ICMP_SLT) {
+ pred = ICmpInst::ICMP_SLE;
+ return true;
+ }
+ } else if (RHS->isAllOnesValue()) {
+ if (pred == ICmpInst::ICMP_SGT) {
+ pred = ICmpInst::ICMP_SGE;
+ return true;
+ }
+ }
+
+ return false;
+}
+
// isHighOnes - Return true if the constant is of the form 1+0+.
// This is the same as lowones(~X).
static bool isHighOnes(const ConstantInt *CI) {
// We need TD information to know the pointer size unless this is inbounds.
if (!GEP->isInBounds() && TD == 0) return 0;
- ConstantArray *Init = dyn_cast<ConstantArray>(GV->getInitializer());
- if (Init == 0 || Init->getNumOperands() > 1024) return 0;
+ Constant *Init = GV->getInitializer();
+ if (!isa<ConstantArray>(Init) && !isa<ConstantDataArray>(Init))
+ return 0;
+
+ uint64_t ArrayElementCount = Init->getType()->getArrayNumElements();
+ if (ArrayElementCount > 1024) return 0; // Don't blow up on huge arrays.
// There are many forms of this optimization we can handle, for now, just do
// the simple index into a single-dimensional array.
// structs.
SmallVector<unsigned, 4> LaterIndices;
- Type *EltTy = cast<ArrayType>(Init->getType())->getElementType();
+ Type *EltTy = Init->getType()->getArrayElementType();
for (unsigned i = 3, e = GEP->getNumOperands(); i != e; ++i) {
ConstantInt *Idx = dyn_cast<ConstantInt>(GEP->getOperand(i));
if (Idx == 0) return 0; // Variable index.
// Scan the array and see if one of our patterns matches.
Constant *CompareRHS = cast<Constant>(ICI.getOperand(1));
- for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
- Constant *Elt = Init->getOperand(i);
+ for (unsigned i = 0, e = ArrayElementCount; i != e; ++i) {
+ Constant *Elt = Init->getAggregateElement(i);
+ if (Elt == 0) return 0;
// If this is indexing an array of structures, get the structure element.
if (!LaterIndices.empty())
// Find out if the comparison would be true or false for the i'th element.
Constant *C = ConstantFoldCompareInstOperands(ICI.getPredicate(), Elt,
- CompareRHS, TD);
+ CompareRHS, TD, TLI);
// If the result is undef for this element, ignore it.
if (isa<UndefValue>(C)) {
// Extend range state machines to cover this element in case there is an
if (SecondTrueElement != Overdefined) {
// None true -> false.
if (FirstTrueElement == Undefined)
- return ReplaceInstUsesWith(ICI, ConstantInt::getFalse(GEP->getContext()));
+ return ReplaceInstUsesWith(ICI, Builder->getFalse());
Value *FirstTrueIdx = ConstantInt::get(Idx->getType(), FirstTrueElement);
if (SecondFalseElement != Overdefined) {
// None false -> true.
if (FirstFalseElement == Undefined)
- return ReplaceInstUsesWith(ICI, ConstantInt::getTrue(GEP->getContext()));
+ return ReplaceInstUsesWith(ICI, Builder->getTrue());
Value *FirstFalseIdx = ConstantInt::get(Idx->getType(), FirstFalseElement);
}
- // If a 32-bit or 64-bit magic bitvector captures the entire comparison state
+ // If a magic bitvector captures the entire comparison state
// of this load, replace it with computation that does:
// ((magic_cst >> i) & 1) != 0
- if (Init->getNumOperands() <= 32 ||
- (TD && Init->getNumOperands() <= 64 && TD->isLegalInteger(64))) {
- Type *Ty;
- if (Init->getNumOperands() <= 32)
+ {
+ Type *Ty = 0;
+
+ // Look for an appropriate type:
+ // - The type of Idx if the magic fits
+ // - The smallest fitting legal type if we have a DataLayout
+ // - Default to i32
+ if (ArrayElementCount <= Idx->getType()->getIntegerBitWidth())
+ Ty = Idx->getType();
+ else if (TD)
+ Ty = TD->getSmallestLegalIntType(Init->getContext(), ArrayElementCount);
+ else if (ArrayElementCount <= 32)
Ty = Type::getInt32Ty(Init->getContext());
- else
- Ty = Type::getInt64Ty(Init->getContext());
- Value *V = Builder->CreateIntCast(Idx, Ty, false);
- V = Builder->CreateLShr(ConstantInt::get(Ty, MagicBitvector), V);
- V = Builder->CreateAnd(ConstantInt::get(Ty, 1), V);
- return new ICmpInst(ICmpInst::ICMP_NE, V, ConstantInt::get(Ty, 0));
+
+ if (Ty != 0) {
+ Value *V = Builder->CreateIntCast(Idx, Ty, false);
+ V = Builder->CreateLShr(ConstantInt::get(Ty, MagicBitvector), V);
+ V = Builder->CreateAnd(ConstantInt::get(Ty, 1), V);
+ return new ICmpInst(ICmpInst::ICMP_NE, V, ConstantInt::get(Ty, 0));
+ }
}
return 0;
/// If we can't emit an optimized form for this expression, this returns null.
///
static Value *EvaluateGEPOffsetExpression(User *GEP, InstCombiner &IC) {
- TargetData &TD = *IC.getTargetData();
+ DataLayout &TD = *IC.getDataLayout();
gep_type_iterator GTI = gep_type_begin(GEP);
// Check to see if this gep only has a single variable index. If so, and if
Instruction *InstCombiner::FoldGEPICmp(GEPOperator *GEPLHS, Value *RHS,
ICmpInst::Predicate Cond,
Instruction &I) {
+ // Don't transform signed compares of GEPs into index compares. Even if the
+ // GEP is inbounds, the final add of the base pointer can have signed overflow
+ // and would change the result of the icmp.
+ // e.g. "&foo[0] <s &foo[1]" can't be folded to "true" because "foo" could be
+ // the maximum signed value for the pointer type.
+ if (ICmpInst::isSigned(Cond))
+ return 0;
+
// Look through bitcasts.
if (BitCastInst *BCI = dyn_cast<BitCastInst>(RHS))
RHS = BCI->getOperand(0);
// If all indices are the same, just compare the base pointers.
if (IndicesTheSame)
- return new ICmpInst(ICmpInst::getSignedPredicate(Cond),
- GEPLHS->getOperand(0), GEPRHS->getOperand(0));
+ return new ICmpInst(Cond, GEPLHS->getOperand(0), GEPRHS->getOperand(0));
+
+ // If we're comparing GEPs with two base pointers that only differ in type
+ // and both GEPs have only constant indices or just one use, then fold
+ // the compare with the adjusted indices.
+ if (TD && GEPLHS->isInBounds() && GEPRHS->isInBounds() &&
+ (GEPLHS->hasAllConstantIndices() || GEPLHS->hasOneUse()) &&
+ (GEPRHS->hasAllConstantIndices() || GEPRHS->hasOneUse()) &&
+ PtrBase->stripPointerCasts() ==
+ GEPRHS->getOperand(0)->stripPointerCasts()) {
+ Value *Cmp = Builder->CreateICmp(ICmpInst::getSignedPredicate(Cond),
+ EmitGEPOffset(GEPLHS),
+ EmitGEPOffset(GEPRHS));
+ return ReplaceInstUsesWith(I, Cmp);
+ }
// Otherwise, the base pointers are different and the indices are
// different, bail out.
}
if (AllZeros)
return FoldGEPICmp(GEPRHS, GEPLHS->getOperand(0),
- ICmpInst::getSwappedPredicate(Cond), I);
+ ICmpInst::getSwappedPredicate(Cond), I);
// If the other GEP has all zero indices, recurse.
AllZeros = true;
if (NumDifferences == 0) // SAME GEP?
return ReplaceInstUsesWith(I, // No comparison is needed here.
- ConstantInt::get(Type::getInt1Ty(I.getContext()),
- ICmpInst::isTrueWhenEqual(Cond)));
+ Builder->getInt1(ICmpInst::isTrueWhenEqual(Cond)));
else if (NumDifferences == 1 && GEPsInBounds) {
Value *LHSV = GEPLHS->getOperand(DiffOperand);
// (X+4) == X -> false.
if (Pred == ICmpInst::ICMP_EQ)
- return ReplaceInstUsesWith(ICI, ConstantInt::getFalse(X->getContext()));
+ return ReplaceInstUsesWith(ICI, Builder->getFalse());
// (X+4) != X -> true.
if (Pred == ICmpInst::ICMP_NE)
- return ReplaceInstUsesWith(ICI, ConstantInt::getTrue(X->getContext()));
+ return ReplaceInstUsesWith(ICI, Builder->getTrue());
// From this point on, we know that (X+C <= X) --> (X+C < X) because C != 0,
// so the values can never be equal. Similarly for all other "or equals"
// (X+ -1) >s X --> X <s (MAXSINT-(-1-1)) --> X == -128
assert(Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SGE);
- Constant *C = ConstantInt::get(X->getContext(), CI->getValue()-1);
+ Constant *C = Builder->getInt(CI->getValue()-1);
return new ICmpInst(ICmpInst::ICMP_SLT, X, ConstantExpr::getSub(SMax, C));
}
default: llvm_unreachable("Unhandled icmp opcode!");
case ICmpInst::ICMP_EQ:
if (LoOverflow && HiOverflow)
- return ReplaceInstUsesWith(ICI, ConstantInt::getFalse(ICI.getContext()));
+ return ReplaceInstUsesWith(ICI, Builder->getFalse());
if (HiOverflow)
return new ICmpInst(DivIsSigned ? ICmpInst::ICMP_SGE :
ICmpInst::ICMP_UGE, X, LoBound);
DivIsSigned, true));
case ICmpInst::ICMP_NE:
if (LoOverflow && HiOverflow)
- return ReplaceInstUsesWith(ICI, ConstantInt::getTrue(ICI.getContext()));
+ return ReplaceInstUsesWith(ICI, Builder->getTrue());
if (HiOverflow)
return new ICmpInst(DivIsSigned ? ICmpInst::ICMP_SLT :
ICmpInst::ICMP_ULT, X, LoBound);
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_SLT:
if (LoOverflow == +1) // Low bound is greater than input range.
- return ReplaceInstUsesWith(ICI, ConstantInt::getTrue(ICI.getContext()));
+ return ReplaceInstUsesWith(ICI, Builder->getTrue());
if (LoOverflow == -1) // Low bound is less than input range.
- return ReplaceInstUsesWith(ICI, ConstantInt::getFalse(ICI.getContext()));
+ return ReplaceInstUsesWith(ICI, Builder->getFalse());
return new ICmpInst(Pred, X, LoBound);
case ICmpInst::ICMP_UGT:
case ICmpInst::ICMP_SGT:
if (HiOverflow == +1) // High bound greater than input range.
- return ReplaceInstUsesWith(ICI, ConstantInt::getFalse(ICI.getContext()));
+ return ReplaceInstUsesWith(ICI, Builder->getFalse());
if (HiOverflow == -1) // High bound less than input range.
- return ReplaceInstUsesWith(ICI, ConstantInt::getTrue(ICI.getContext()));
+ return ReplaceInstUsesWith(ICI, Builder->getTrue());
if (Pred == ICmpInst::ICMP_UGT)
return new ICmpInst(ICmpInst::ICMP_UGE, X, HiBound);
return new ICmpInst(ICmpInst::ICMP_SGE, X, HiBound);
// If we are comparing against bits always shifted out, the
// comparison cannot succeed.
APInt Comp = CmpRHSV << ShAmtVal;
- ConstantInt *ShiftedCmpRHS = ConstantInt::get(ICI.getContext(), Comp);
+ ConstantInt *ShiftedCmpRHS = Builder->getInt(Comp);
if (Shr->getOpcode() == Instruction::LShr)
Comp = Comp.lshr(ShAmtVal);
else
if (Comp != CmpRHSV) { // Comparing against a bit that we know is zero.
bool IsICMP_NE = ICI.getPredicate() == ICmpInst::ICMP_NE;
- Constant *Cst = ConstantInt::get(Type::getInt1Ty(ICI.getContext()),
- IsICMP_NE);
+ Constant *Cst = Builder->getInt1(IsICMP_NE);
return ReplaceInstUsesWith(ICI, Cst);
}
if (Shr->hasOneUse()) {
// Otherwise strength reduce the shift into an and.
APInt Val(APInt::getHighBitsSet(TypeBits, TypeBits - ShAmtVal));
- Constant *Mask = ConstantInt::get(ICI.getContext(), Val);
+ Constant *Mask = Builder->getInt(Val);
Value *And = Builder->CreateAnd(Shr->getOperand(0),
Mask, Shr->getName()+".mask");
// of the high bits truncated out of x are known.
unsigned DstBits = LHSI->getType()->getPrimitiveSizeInBits(),
SrcBits = LHSI->getOperand(0)->getType()->getPrimitiveSizeInBits();
- APInt Mask(APInt::getHighBitsSet(SrcBits, SrcBits-DstBits));
APInt KnownZero(SrcBits, 0), KnownOne(SrcBits, 0);
- ComputeMaskedBits(LHSI->getOperand(0), Mask, KnownZero, KnownOne);
+ ComputeMaskedBits(LHSI->getOperand(0), KnownZero, KnownOne);
// If all the high bits are known, we can do this xform.
if ((KnownZero|KnownOne).countLeadingOnes() >= SrcBits-DstBits) {
// Pull in the high bits from known-ones set.
APInt NewRHS = RHS->getValue().zext(SrcBits);
- NewRHS |= KnownOne;
+ NewRHS |= KnownOne & APInt::getHighBitsSet(SrcBits, SrcBits-DstBits);
return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0),
- ConstantInt::get(ICI.getContext(), NewRHS));
+ Builder->getInt(NewRHS));
}
}
break;
? ICI.getUnsignedPredicate()
: ICI.getSignedPredicate();
return new ICmpInst(Pred, LHSI->getOperand(0),
- ConstantInt::get(ICI.getContext(),
- RHSV ^ SignBit));
+ Builder->getInt(RHSV ^ SignBit));
}
// (icmp u/s (xor A ~SignBit), C) -> (icmp s/u (xor C ~SignBit), A)
: ICI.getSignedPredicate();
Pred = ICI.getSwappedPredicate(Pred);
return new ICmpInst(Pred, LHSI->getOperand(0),
- ConstantInt::get(ICI.getContext(),
- RHSV ^ NotSignBit));
+ Builder->getInt(RHSV ^ NotSignBit));
}
}
+
+ // (icmp ugt (xor X, C), ~C) -> (icmp ult X, C)
+ // iff -C is a power of 2
+ if (ICI.getPredicate() == ICmpInst::ICMP_UGT &&
+ XorCST->getValue() == ~RHSV && (RHSV + 1).isPowerOf2())
+ return new ICmpInst(ICmpInst::ICMP_ULT, LHSI->getOperand(0), XorCST);
+
+ // (icmp ult (xor X, C), -C) -> (icmp uge X, C)
+ // iff -C is a power of 2
+ if (ICI.getPredicate() == ICmpInst::ICMP_ULT &&
+ XorCST->getValue() == -RHSV && RHSV.isPowerOf2())
+ return new ICmpInst(ICmpInst::ICMP_UGE, LHSI->getOperand(0), XorCST);
}
break;
case Instruction::And: // (icmp pred (and X, AndCST), RHS)
// As a special case, check to see if this means that the
// result is always true or false now.
if (ICI.getPredicate() == ICmpInst::ICMP_EQ)
- return ReplaceInstUsesWith(ICI,
- ConstantInt::getFalse(ICI.getContext()));
+ return ReplaceInstUsesWith(ICI, Builder->getFalse());
if (ICI.getPredicate() == ICmpInst::ICMP_NE)
- return ReplaceInstUsesWith(ICI,
- ConstantInt::getTrue(ICI.getContext()));
+ return ReplaceInstUsesWith(ICI, Builder->getTrue());
} else {
ICI.setOperand(1, NewCst);
Constant *NewAndCST;
ICI.setOperand(0, NewAnd);
return &ICI;
}
+
+ // Replace ((X & AndCST) > RHSV) with ((X & AndCST) != 0), if any
+ // bit set in (X & AndCST) will produce a result greater than RHSV.
+ if (ICI.getPredicate() == ICmpInst::ICMP_UGT) {
+ unsigned NTZ = AndCST->getValue().countTrailingZeros();
+ if ((NTZ < AndCST->getBitWidth()) &&
+ APInt::getOneBitSet(AndCST->getBitWidth(), NTZ).ugt(RHSV))
+ return new ICmpInst(ICmpInst::ICMP_NE, LHSI,
+ Constant::getNullValue(RHS->getType()));
+ }
}
// Try to optimize things like "A[i]&42 == 0" to index computations.
return Res;
}
}
+
+ // X & -C == -C -> X > u ~C
+ // X & -C != -C -> X <= u ~C
+ // iff C is a power of 2
+ if (ICI.isEquality() && RHS == LHSI->getOperand(1) && (-RHSV).isPowerOf2())
+ return new ICmpInst(
+ ICI.getPredicate() == ICmpInst::ICMP_EQ ? ICmpInst::ICMP_UGT
+ : ICmpInst::ICMP_ULE,
+ LHSI->getOperand(0), SubOne(RHS));
break;
case Instruction::Or: {
break;
}
+ case Instruction::Mul: { // (icmp pred (mul X, Val), CI)
+ ConstantInt *Val = dyn_cast<ConstantInt>(LHSI->getOperand(1));
+ if (!Val) break;
+
+ // If this is a signed comparison to 0 and the mul is sign preserving,
+ // use the mul LHS operand instead.
+ ICmpInst::Predicate pred = ICI.getPredicate();
+ if (isSignTest(pred, RHS) && !Val->isZero() &&
+ cast<BinaryOperator>(LHSI)->hasNoSignedWrap())
+ return new ICmpInst(Val->isNegative() ?
+ ICmpInst::getSwappedPredicate(pred) : pred,
+ LHSI->getOperand(0),
+ Constant::getNullValue(RHS->getType()));
+
+ break;
+ }
+
case Instruction::Shl: { // (icmp pred (shl X, ShAmt), CI)
+ uint32_t TypeBits = RHSV.getBitWidth();
ConstantInt *ShAmt = dyn_cast<ConstantInt>(LHSI->getOperand(1));
- if (!ShAmt) break;
+ if (!ShAmt) {
+ Value *X;
+ // (1 << X) pred P2 -> X pred Log2(P2)
+ if (match(LHSI, m_Shl(m_One(), m_Value(X)))) {
+ bool RHSVIsPowerOf2 = RHSV.isPowerOf2();
+ ICmpInst::Predicate Pred = ICI.getPredicate();
+ if (ICI.isUnsigned()) {
+ if (!RHSVIsPowerOf2) {
+ // (1 << X) < 30 -> X <= 4
+ // (1 << X) <= 30 -> X <= 4
+ // (1 << X) >= 30 -> X > 4
+ // (1 << X) > 30 -> X > 4
+ if (Pred == ICmpInst::ICMP_ULT)
+ Pred = ICmpInst::ICMP_ULE;
+ else if (Pred == ICmpInst::ICMP_UGE)
+ Pred = ICmpInst::ICMP_UGT;
+ }
+ unsigned RHSLog2 = RHSV.logBase2();
+
+ // (1 << X) >= 2147483648 -> X >= 31 -> X == 31
+ // (1 << X) > 2147483648 -> X > 31 -> false
+ // (1 << X) <= 2147483648 -> X <= 31 -> true
+ // (1 << X) < 2147483648 -> X < 31 -> X != 31
+ if (RHSLog2 == TypeBits-1) {
+ if (Pred == ICmpInst::ICMP_UGE)
+ Pred = ICmpInst::ICMP_EQ;
+ else if (Pred == ICmpInst::ICMP_UGT)
+ return ReplaceInstUsesWith(ICI, Builder->getFalse());
+ else if (Pred == ICmpInst::ICMP_ULE)
+ return ReplaceInstUsesWith(ICI, Builder->getTrue());
+ else if (Pred == ICmpInst::ICMP_ULT)
+ Pred = ICmpInst::ICMP_NE;
+ }
- uint32_t TypeBits = RHSV.getBitWidth();
+ return new ICmpInst(Pred, X,
+ ConstantInt::get(RHS->getType(), RHSLog2));
+ } else if (ICI.isSigned()) {
+ if (RHSV.isAllOnesValue()) {
+ // (1 << X) <= -1 -> X == 31
+ if (Pred == ICmpInst::ICMP_SLE)
+ return new ICmpInst(ICmpInst::ICMP_EQ, X,
+ ConstantInt::get(RHS->getType(), TypeBits-1));
+
+ // (1 << X) > -1 -> X != 31
+ if (Pred == ICmpInst::ICMP_SGT)
+ return new ICmpInst(ICmpInst::ICMP_NE, X,
+ ConstantInt::get(RHS->getType(), TypeBits-1));
+ } else if (!RHSV) {
+ // (1 << X) < 0 -> X == 31
+ // (1 << X) <= 0 -> X == 31
+ if (Pred == ICmpInst::ICMP_SLT || Pred == ICmpInst::ICMP_SLE)
+ return new ICmpInst(ICmpInst::ICMP_EQ, X,
+ ConstantInt::get(RHS->getType(), TypeBits-1));
+
+ // (1 << X) >= 0 -> X != 31
+ // (1 << X) > 0 -> X != 31
+ if (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SGE)
+ return new ICmpInst(ICmpInst::ICMP_NE, X,
+ ConstantInt::get(RHS->getType(), TypeBits-1));
+ }
+ } else if (ICI.isEquality()) {
+ if (RHSVIsPowerOf2)
+ return new ICmpInst(
+ Pred, X, ConstantInt::get(RHS->getType(), RHSV.logBase2()));
+
+ return ReplaceInstUsesWith(
+ ICI, Pred == ICmpInst::ICMP_EQ ? Builder->getFalse()
+ : Builder->getTrue());
+ }
+ }
+ break;
+ }
// Check that the shift amount is in range. If not, don't perform
// undefined shifts. When the shift is visited it will be
ShAmt);
if (Comp != RHS) {// Comparing against a bit that we know is zero.
bool IsICMP_NE = ICI.getPredicate() == ICmpInst::ICMP_NE;
- Constant *Cst =
- ConstantInt::get(Type::getInt1Ty(ICI.getContext()), IsICMP_NE);
+ Constant *Cst = Builder->getInt1(IsICMP_NE);
return ReplaceInstUsesWith(ICI, Cst);
}
return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0),
ConstantExpr::getLShr(RHS, ShAmt));
+ // If the shift is NSW and we compare to 0, then it is just shifting out
+ // sign bits, no need for an AND either.
+ if (cast<BinaryOperator>(LHSI)->hasNoSignedWrap() && RHSV == 0)
+ return new ICmpInst(ICI.getPredicate(), LHSI->getOperand(0),
+ ConstantExpr::getLShr(RHS, ShAmt));
+
if (LHSI->hasOneUse()) {
// Otherwise strength reduce the shift into an and.
uint32_t ShAmtVal = (uint32_t)ShAmt->getLimitedValue(TypeBits);
- Constant *Mask =
- ConstantInt::get(ICI.getContext(), APInt::getLowBitsSet(TypeBits,
- TypeBits-ShAmtVal));
+ Constant *Mask = Builder->getInt(APInt::getLowBitsSet(TypeBits,
+ TypeBits - ShAmtVal));
Value *And =
Builder->CreateAnd(LHSI->getOperand(0),Mask, LHSI->getName()+".mask");
}
}
+ // If this is a signed comparison to 0 and the shift is sign preserving,
+ // use the shift LHS operand instead.
+ ICmpInst::Predicate pred = ICI.getPredicate();
+ if (isSignTest(pred, RHS) &&
+ cast<BinaryOperator>(LHSI)->hasNoSignedWrap())
+ return new ICmpInst(pred,
+ LHSI->getOperand(0),
+ Constant::getNullValue(RHS->getType()));
+
// Otherwise, if this is a comparison of the sign bit, simplify to and/test.
bool TrueIfSigned = false;
if (LHSI->hasOneUse() &&
return new ICmpInst(TrueIfSigned ? ICmpInst::ICMP_NE : ICmpInst::ICMP_EQ,
And, Constant::getNullValue(And->getType()));
}
+
+ // Transform (icmp pred iM (shl iM %v, N), CI)
+ // -> (icmp pred i(M-N) (trunc %v iM to i(M-N)), (trunc (CI>>N))
+ // Transform the shl to a trunc if (trunc (CI>>N)) has no loss and M-N.
+ // This enables to get rid of the shift in favor of a trunc which can be
+ // free on the target. It has the additional benefit of comparing to a
+ // smaller constant, which will be target friendly.
+ unsigned Amt = ShAmt->getLimitedValue(TypeBits-1);
+ if (LHSI->hasOneUse() &&
+ Amt != 0 && RHSV.countTrailingZeros() >= Amt) {
+ Type *NTy = IntegerType::get(ICI.getContext(), TypeBits - Amt);
+ Constant *NCI = ConstantExpr::getTrunc(
+ ConstantExpr::getAShr(RHS,
+ ConstantInt::get(RHS->getType(), Amt)),
+ NTy);
+ return new ICmpInst(ICI.getPredicate(),
+ Builder->CreateTrunc(LHSI->getOperand(0), NTy),
+ NCI);
+ }
+
break;
}
return R;
break;
+ case Instruction::Sub: {
+ ConstantInt *LHSC = dyn_cast<ConstantInt>(LHSI->getOperand(0));
+ if (!LHSC) break;
+ const APInt &LHSV = LHSC->getValue();
+
+ // C1-X <u C2 -> (X|(C2-1)) == C1
+ // iff C1 & (C2-1) == C2-1
+ // C2 is a power of 2
+ if (ICI.getPredicate() == ICmpInst::ICMP_ULT && LHSI->hasOneUse() &&
+ RHSV.isPowerOf2() && (LHSV & (RHSV - 1)) == (RHSV - 1))
+ return new ICmpInst(ICmpInst::ICMP_EQ,
+ Builder->CreateOr(LHSI->getOperand(1), RHSV - 1),
+ LHSC);
+
+ // C1-X >u C2 -> (X|C2) != C1
+ // iff C1 & C2 == C2
+ // C2+1 is a power of 2
+ if (ICI.getPredicate() == ICmpInst::ICMP_UGT && LHSI->hasOneUse() &&
+ (RHSV + 1).isPowerOf2() && (LHSV & RHSV) == RHSV)
+ return new ICmpInst(ICmpInst::ICMP_NE,
+ Builder->CreateOr(LHSI->getOperand(1), RHSV), LHSC);
+ break;
+ }
+
case Instruction::Add:
// Fold: icmp pred (add X, C1), C2
if (!ICI.isEquality()) {
if (ICI.isSigned()) {
if (CR.getLower().isSignBit()) {
return new ICmpInst(ICmpInst::ICMP_SLT, LHSI->getOperand(0),
- ConstantInt::get(ICI.getContext(),CR.getUpper()));
+ Builder->getInt(CR.getUpper()));
} else if (CR.getUpper().isSignBit()) {
return new ICmpInst(ICmpInst::ICMP_SGE, LHSI->getOperand(0),
- ConstantInt::get(ICI.getContext(),CR.getLower()));
+ Builder->getInt(CR.getLower()));
}
} else {
if (CR.getLower().isMinValue()) {
return new ICmpInst(ICmpInst::ICMP_ULT, LHSI->getOperand(0),
- ConstantInt::get(ICI.getContext(),CR.getUpper()));
+ Builder->getInt(CR.getUpper()));
} else if (CR.getUpper().isMinValue()) {
return new ICmpInst(ICmpInst::ICMP_UGE, LHSI->getOperand(0),
- ConstantInt::get(ICI.getContext(),CR.getLower()));
+ Builder->getInt(CR.getLower()));
}
}
+
+ // X-C1 <u C2 -> (X & -C2) == C1
+ // iff C1 & (C2-1) == 0
+ // C2 is a power of 2
+ if (ICI.getPredicate() == ICmpInst::ICMP_ULT && LHSI->hasOneUse() &&
+ RHSV.isPowerOf2() && (LHSV & (RHSV - 1)) == 0)
+ return new ICmpInst(ICmpInst::ICMP_EQ,
+ Builder->CreateAnd(LHSI->getOperand(0), -RHSV),
+ ConstantExpr::getNeg(LHSC));
+
+ // X-C1 >u C2 -> (X & ~C2) != C1
+ // iff C1 & C2 == 0
+ // C2+1 is a power of 2
+ if (ICI.getPredicate() == ICmpInst::ICMP_UGT && LHSI->hasOneUse() &&
+ (RHSV + 1).isPowerOf2() && (LHSV & RHSV) == 0)
+ return new ICmpInst(ICmpInst::ICMP_NE,
+ Builder->CreateAnd(LHSI->getOperand(0), ~RHSV),
+ ConstantExpr::getNeg(LHSC));
}
break;
}
if (ConstantInt *BOC = dyn_cast<ConstantInt>(BO->getOperand(1))) {
Constant *NotCI = ConstantExpr::getNot(RHS);
if (!ConstantExpr::getAnd(BOC, NotCI)->isNullValue())
- return ReplaceInstUsesWith(ICI,
- ConstantInt::get(Type::getInt1Ty(ICI.getContext()),
- isICMP_NE));
+ return ReplaceInstUsesWith(ICI, Builder->getInt1(isICMP_NE));
}
break;
// If bits are being compared against that are and'd out, then the
// comparison can never succeed!
if ((RHSV & ~BOC->getValue()) != 0)
- return ReplaceInstUsesWith(ICI,
- ConstantInt::get(Type::getInt1Ty(ICI.getContext()),
- isICMP_NE));
+ return ReplaceInstUsesWith(ICI, Builder->getInt1(isICMP_NE));
// If we have ((X & C) == C), turn it into ((X & C) != 0).
if (RHS == BOC && RHSV.isPowerOf2())
return new ICmpInst(pred, X, NegX);
}
}
+ break;
+ case Instruction::Mul:
+ if (RHSV == 0 && BO->hasNoSignedWrap()) {
+ if (ConstantInt *BOC = dyn_cast<ConstantInt>(BO->getOperand(1))) {
+ // The trivial case (mul X, 0) is handled by InstSimplify
+ // General case : (mul X, C) != 0 iff X != 0
+ // (mul X, C) == 0 iff X == 0
+ if (!BOC->isZero())
+ return new ICmpInst(ICI.getPredicate(), BO->getOperand(0),
+ Constant::getNullValue(RHS->getType()));
+ }
+ }
+ break;
default: break;
}
} else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(LHSI)) {
case Intrinsic::bswap:
Worklist.Add(II);
ICI.setOperand(0, II->getArgOperand(0));
- ICI.setOperand(1, ConstantInt::get(II->getContext(), RHSV.byteSwap()));
+ ICI.setOperand(1, Builder->getInt(RHSV.byteSwap()));
return &ICI;
case Intrinsic::ctlz:
case Intrinsic::cttz:
CI1->getValue() != APInt::getLowBitsSet(CI1->getBitWidth(), NewWidth))
return 0;
+ // This is only really a signed overflow check if the inputs have been
+ // sign-extended; check for that condition. For example, if CI2 is 2^31 and
+ // the operands of the add are 64 bits wide, we need at least 33 sign bits.
+ unsigned NeededSignBits = CI1->getBitWidth() - NewWidth + 1;
+ if (IC.ComputeNumSignBits(A) < NeededSignBits ||
+ IC.ComputeNumSignBits(B) < NeededSignBits)
+ return 0;
+
// In order to replace the original add with a narrower
// llvm.sadd.with.overflow, the only uses allowed are the add-with-constant
// and truncates that discard the high bits of the add. Verify that this is
if (Value *V = SimplifyICmpInst(I.getPredicate(), Op0, Op1, TD))
return ReplaceInstUsesWith(I, V);
+ // comparing -val or val with non-zero is the same as just comparing val
+ // ie, abs(val) != 0 -> val != 0
+ if (I.getPredicate() == ICmpInst::ICMP_NE && match(Op1, m_Zero()))
+ {
+ Value *Cond, *SelectTrue, *SelectFalse;
+ if (match(Op0, m_Select(m_Value(Cond), m_Value(SelectTrue),
+ m_Value(SelectFalse)))) {
+ if (Value *V = dyn_castNegVal(SelectTrue)) {
+ if (V == SelectFalse)
+ return CmpInst::Create(Instruction::ICmp, I.getPredicate(), V, Op1);
+ }
+ else if (Value *V = dyn_castNegVal(SelectFalse)) {
+ if (V == SelectTrue)
+ return CmpInst::Create(Instruction::ICmp, I.getPredicate(), V, Op1);
+ }
+ }
+ }
+
Type *Ty = Op0->getType();
// icmp's with boolean values can always be turned into bitwise operations
case ICmpInst::ICMP_ULE:
assert(!CI->isMaxValue(false)); // A <=u MAX -> TRUE
return new ICmpInst(ICmpInst::ICMP_ULT, Op0,
- ConstantInt::get(CI->getContext(), CI->getValue()+1));
+ Builder->getInt(CI->getValue()+1));
case ICmpInst::ICMP_SLE:
assert(!CI->isMaxValue(true)); // A <=s MAX -> TRUE
return new ICmpInst(ICmpInst::ICMP_SLT, Op0,
- ConstantInt::get(CI->getContext(), CI->getValue()+1));
+ Builder->getInt(CI->getValue()+1));
case ICmpInst::ICMP_UGE:
assert(!CI->isMinValue(false)); // A >=u MIN -> TRUE
return new ICmpInst(ICmpInst::ICMP_UGT, Op0,
- ConstantInt::get(CI->getContext(), CI->getValue()-1));
+ Builder->getInt(CI->getValue()-1));
case ICmpInst::ICMP_SGE:
assert(!CI->isMinValue(true)); // A >=s MIN -> TRUE
return new ICmpInst(ICmpInst::ICMP_SGT, Op0,
- ConstantInt::get(CI->getContext(), CI->getValue()-1));
+ Builder->getInt(CI->getValue()-1));
}
// If this comparison is a normal comparison, it demands all
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
if (Op1Max == Op0Min+1) // A <u C -> A == C-1 if min(A)+1 == C
return new ICmpInst(ICmpInst::ICMP_EQ, Op0,
- ConstantInt::get(CI->getContext(), CI->getValue()-1));
+ Builder->getInt(CI->getValue()-1));
// (x <u 2147483648) -> (x >s -1) -> true if sign bit clear
if (CI->isMinValue(true))
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
if (Op1Min == Op0Max-1) // A >u C -> A == C+1 if max(a)-1 == C
return new ICmpInst(ICmpInst::ICMP_EQ, Op0,
- ConstantInt::get(CI->getContext(), CI->getValue()+1));
+ Builder->getInt(CI->getValue()+1));
// (x >u 2147483647) -> (x <s 0) -> true if sign bit set
if (CI->isMaxValue(true))
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
if (Op1Max == Op0Min+1) // A <s C -> A == C-1 if min(A)+1 == C
return new ICmpInst(ICmpInst::ICMP_EQ, Op0,
- ConstantInt::get(CI->getContext(), CI->getValue()-1));
+ Builder->getInt(CI->getValue()-1));
}
break;
case ICmpInst::ICMP_SGT:
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
if (Op1Min == Op0Max-1) // A >s C -> A == C+1 if max(A)-1 == C
return new ICmpInst(ICmpInst::ICMP_EQ, Op0,
- ConstantInt::get(CI->getContext(), CI->getValue()+1));
+ Builder->getInt(CI->getValue()+1));
}
break;
case ICmpInst::ICMP_SGE:
// Try not to increase register pressure.
BO0->hasOneUse() && BO1->hasOneUse()) {
// Determine Y and Z in the form icmp (X+Y), (X+Z).
- Value *Y = (A == C || A == D) ? B : A;
- Value *Z = (C == A || C == B) ? D : C;
+ Value *Y, *Z;
+ if (A == C) {
+ // C + B == C + D -> B == D
+ Y = B;
+ Z = D;
+ } else if (A == D) {
+ // D + B == C + D -> B == C
+ Y = B;
+ Z = C;
+ } else if (B == C) {
+ // A + C == C + D -> A == D
+ Y = A;
+ Z = D;
+ } else {
+ assert(B == D);
+ // A + D == C + D -> A == C
+ Y = A;
+ Z = C;
+ }
return new ICmpInst(Pred, Y, Z);
}
+ // icmp slt (X + -1), Y -> icmp sle X, Y
+ if (A && NoOp0WrapProblem && Pred == CmpInst::ICMP_SLT &&
+ match(B, m_AllOnes()))
+ return new ICmpInst(CmpInst::ICMP_SLE, A, Op1);
+
+ // icmp sge (X + -1), Y -> icmp sgt X, Y
+ if (A && NoOp0WrapProblem && Pred == CmpInst::ICMP_SGE &&
+ match(B, m_AllOnes()))
+ return new ICmpInst(CmpInst::ICMP_SGT, A, Op1);
+
+ // icmp sle (X + 1), Y -> icmp slt X, Y
+ if (A && NoOp0WrapProblem && Pred == CmpInst::ICMP_SLE &&
+ match(B, m_One()))
+ return new ICmpInst(CmpInst::ICMP_SLT, A, Op1);
+
+ // icmp sgt (X + 1), Y -> icmp sge X, Y
+ if (A && NoOp0WrapProblem && Pred == CmpInst::ICMP_SGT &&
+ match(B, m_One()))
+ return new ICmpInst(CmpInst::ICMP_SGE, A, Op1);
+
+ // if C1 has greater magnitude than C2:
+ // icmp (X + C1), (Y + C2) -> icmp (X + C3), Y
+ // s.t. C3 = C1 - C2
+ //
+ // if C2 has greater magnitude than C1:
+ // icmp (X + C1), (Y + C2) -> icmp X, (Y + C3)
+ // s.t. C3 = C2 - C1
+ if (A && C && NoOp0WrapProblem && NoOp1WrapProblem &&
+ (BO0->hasOneUse() || BO1->hasOneUse()) && !I.isUnsigned())
+ if (ConstantInt *C1 = dyn_cast<ConstantInt>(B))
+ if (ConstantInt *C2 = dyn_cast<ConstantInt>(D)) {
+ const APInt &AP1 = C1->getValue();
+ const APInt &AP2 = C2->getValue();
+ if (AP1.isNegative() == AP2.isNegative()) {
+ APInt AP1Abs = C1->getValue().abs();
+ APInt AP2Abs = C2->getValue().abs();
+ if (AP1Abs.uge(AP2Abs)) {
+ ConstantInt *C3 = Builder->getInt(AP1 - AP2);
+ Value *NewAdd = Builder->CreateNSWAdd(A, C3);
+ return new ICmpInst(Pred, NewAdd, C);
+ } else {
+ ConstantInt *C3 = Builder->getInt(AP2 - AP1);
+ Value *NewAdd = Builder->CreateNSWAdd(C, C3);
+ return new ICmpInst(Pred, A, NewAdd);
+ }
+ }
+ }
+
+
// Analyze the case when either Op0 or Op1 is a sub instruction.
// Op0 = A - B (or A and B are null); Op1 = C - D (or C and D are null).
A = 0; B = 0; C = 0; D = 0;
}
{ Value *A, *B;
+ // Transform (A & ~B) == 0 --> (A & B) != 0
+ // and (A & ~B) != 0 --> (A & B) == 0
+ // if A is a power of 2.
+ if (match(Op0, m_And(m_Value(A), m_Not(m_Value(B)))) &&
+ match(Op1, m_Zero()) && isKnownToBeAPowerOfTwo(A) && I.isEquality())
+ return new ICmpInst(I.getInversePredicate(),
+ Builder->CreateAnd(A, B),
+ Op1);
+
// ~x < ~y --> y < x
// ~x < cst --> ~cst < x
if (match(Op0, m_Not(m_Value(A)))) {
ConstantInt *C1, *C2;
if (match(B, m_ConstantInt(C1)) &&
match(D, m_ConstantInt(C2)) && Op1->hasOneUse()) {
- Constant *NC = ConstantInt::get(I.getContext(),
- C1->getValue() ^ C2->getValue());
+ Constant *NC = Builder->getInt(C1->getValue() ^ C2->getValue());
Value *Xor = Builder->CreateXor(C, NC);
return new ICmpInst(I.getPredicate(), A, Xor);
}
}
}
+ // Transform (zext A) == (B & (1<<X)-1) --> A == (trunc B)
+ // and (B & (1<<X)-1) == (zext A) --> A == (trunc B)
+ ConstantInt *Cst1;
+ if ((Op0->hasOneUse() &&
+ match(Op0, m_ZExt(m_Value(A))) &&
+ match(Op1, m_And(m_Value(B), m_ConstantInt(Cst1)))) ||
+ (Op1->hasOneUse() &&
+ match(Op0, m_And(m_Value(B), m_ConstantInt(Cst1))) &&
+ match(Op1, m_ZExt(m_Value(A))))) {
+ APInt Pow2 = Cst1->getValue() + 1;
+ if (Pow2.isPowerOf2() && isa<IntegerType>(A->getType()) &&
+ Pow2.logBase2() == cast<IntegerType>(A->getType())->getBitWidth())
+ return new ICmpInst(I.getPredicate(), A,
+ Builder->CreateTrunc(B, A->getType()));
+ }
+
// 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))))) &&
Pred = ICmpInst::ICMP_NE;
break;
case FCmpInst::FCMP_ORD:
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ return ReplaceInstUsesWith(I, Builder->getTrue());
case FCmpInst::FCMP_UNO:
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, Builder->getFalse());
}
IntegerType *IntTy = cast<IntegerType>(LHSI->getOperand(0)->getType());
if (!LHSUnsigned) {
// If the RHS value is > SignedMax, fold the comparison. This handles +INF
// and large values.
- APFloat SMax(RHS.getSemantics(), APFloat::fcZero, false);
+ APFloat SMax(RHS.getSemantics());
SMax.convertFromAPInt(APInt::getSignedMaxValue(IntWidth), true,
APFloat::rmNearestTiesToEven);
if (SMax.compare(RHS) == APFloat::cmpLessThan) { // smax < 13123.0
if (Pred == ICmpInst::ICMP_NE || Pred == ICmpInst::ICMP_SLT ||
Pred == ICmpInst::ICMP_SLE)
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, Builder->getTrue());
+ return ReplaceInstUsesWith(I, Builder->getFalse());
}
} else {
// If the RHS value is > UnsignedMax, fold the comparison. This handles
// +INF and large values.
- APFloat UMax(RHS.getSemantics(), APFloat::fcZero, false);
+ APFloat UMax(RHS.getSemantics());
UMax.convertFromAPInt(APInt::getMaxValue(IntWidth), false,
APFloat::rmNearestTiesToEven);
if (UMax.compare(RHS) == APFloat::cmpLessThan) { // umax < 13123.0
if (Pred == ICmpInst::ICMP_NE || Pred == ICmpInst::ICMP_ULT ||
Pred == ICmpInst::ICMP_ULE)
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, Builder->getTrue());
+ return ReplaceInstUsesWith(I, Builder->getFalse());
}
}
if (!LHSUnsigned) {
// See if the RHS value is < SignedMin.
- APFloat SMin(RHS.getSemantics(), APFloat::fcZero, false);
+ APFloat SMin(RHS.getSemantics());
SMin.convertFromAPInt(APInt::getSignedMinValue(IntWidth), true,
APFloat::rmNearestTiesToEven);
if (SMin.compare(RHS) == APFloat::cmpGreaterThan) { // smin > 12312.0
if (Pred == ICmpInst::ICMP_NE || Pred == ICmpInst::ICMP_SGT ||
Pred == ICmpInst::ICMP_SGE)
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, Builder->getTrue());
+ return ReplaceInstUsesWith(I, Builder->getFalse());
+ }
+ } else {
+ // See if the RHS value is < UnsignedMin.
+ APFloat SMin(RHS.getSemantics());
+ SMin.convertFromAPInt(APInt::getMinValue(IntWidth), true,
+ APFloat::rmNearestTiesToEven);
+ if (SMin.compare(RHS) == APFloat::cmpGreaterThan) { // umin > 12312.0
+ if (Pred == ICmpInst::ICMP_NE || Pred == ICmpInst::ICMP_UGT ||
+ Pred == ICmpInst::ICMP_UGE)
+ return ReplaceInstUsesWith(I, Builder->getTrue());
+ return ReplaceInstUsesWith(I, Builder->getFalse());
}
}
switch (Pred) {
default: llvm_unreachable("Unexpected integer comparison!");
case ICmpInst::ICMP_NE: // (float)int != 4.4 --> true
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ return ReplaceInstUsesWith(I, Builder->getTrue());
case ICmpInst::ICMP_EQ: // (float)int == 4.4 --> false
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, Builder->getFalse());
case ICmpInst::ICMP_ULE:
// (float)int <= 4.4 --> int <= 4
// (float)int <= -4.4 --> false
if (RHS.isNegative())
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, Builder->getFalse());
break;
case ICmpInst::ICMP_SLE:
// (float)int <= 4.4 --> int <= 4
// (float)int < -4.4 --> false
// (float)int < 4.4 --> int <= 4
if (RHS.isNegative())
- return ReplaceInstUsesWith(I, ConstantInt::getFalse(I.getContext()));
+ return ReplaceInstUsesWith(I, Builder->getFalse());
Pred = ICmpInst::ICMP_ULE;
break;
case ICmpInst::ICMP_SLT:
// (float)int > 4.4 --> int > 4
// (float)int > -4.4 --> true
if (RHS.isNegative())
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ return ReplaceInstUsesWith(I, Builder->getTrue());
break;
case ICmpInst::ICMP_SGT:
// (float)int > 4.4 --> int > 4
case ICmpInst::ICMP_UGE:
// (float)int >= -4.4 --> true
// (float)int >= 4.4 --> int > 4
- if (!RHS.isNegative())
- return ReplaceInstUsesWith(I, ConstantInt::getTrue(I.getContext()));
+ if (RHS.isNegative())
+ return ReplaceInstUsesWith(I, Builder->getTrue());
Pred = ICmpInst::ICMP_UGT;
break;
case ICmpInst::ICMP_SGE:
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())
+ if (LHSExt->getSrcTy()->isHalfTy())
+ Sem = &APFloat::IEEEhalf;
+ else if (LHSExt->getSrcTy()->isFloatTy())
Sem = &APFloat::IEEEsingle;
else if (LHSExt->getSrcTy()->isDoubleTy())
Sem = &APFloat::IEEEdouble;
Sem = &APFloat::IEEEquad;
else if (LHSExt->getSrcTy()->isX86_FP80Ty())
Sem = &APFloat::x87DoubleExtended;
+ else if (LHSExt->getSrcTy()->isPPC_FP128Ty())
+ Sem = &APFloat::PPCDoubleDouble;
else
break;
APFloat F = RHSF->getValueAPF();
F.convert(*Sem, APFloat::rmNearestTiesToEven, &Lossy);
- // Avoid lossy conversions and denormals.
+ // Avoid lossy conversions and denormals. Zero is a special case
+ // that's OK to convert.
+ APFloat Fabs = F;
+ Fabs.clearSign();
if (!Lossy &&
- F.compare(APFloat::getSmallestNormalized(*Sem)) !=
- APFloat::cmpLessThan)
+ ((Fabs.compare(APFloat::getSmallestNormalized(*Sem)) !=
+ APFloat::cmpLessThan) || Fabs.isZero()))
+
return new FCmpInst(I.getPredicate(), LHSExt->getOperand(0),
ConstantFP::get(RHSC->getContext(), F));
break;
return Res;
}
break;
+ case Instruction::Call: {
+ CallInst *CI = cast<CallInst>(LHSI);
+ LibFunc::Func Func;
+ // Various optimization for fabs compared with zero.
+ if (RHSC->isNullValue() && CI->getCalledFunction() &&
+ TLI->getLibFunc(CI->getCalledFunction()->getName(), Func) &&
+ TLI->has(Func)) {
+ if (Func == LibFunc::fabs || Func == LibFunc::fabsf ||
+ Func == LibFunc::fabsl) {
+ switch (I.getPredicate()) {
+ default: break;
+ // fabs(x) < 0 --> false
+ case FCmpInst::FCMP_OLT:
+ return ReplaceInstUsesWith(I, Builder->getFalse());
+ // fabs(x) > 0 --> x != 0
+ case FCmpInst::FCMP_OGT:
+ return new FCmpInst(FCmpInst::FCMP_ONE, CI->getArgOperand(0),
+ RHSC);
+ // fabs(x) <= 0 --> x == 0
+ case FCmpInst::FCMP_OLE:
+ return new FCmpInst(FCmpInst::FCMP_OEQ, CI->getArgOperand(0),
+ RHSC);
+ // fabs(x) >= 0 --> !isnan(x)
+ case FCmpInst::FCMP_OGE:
+ return new FCmpInst(FCmpInst::FCMP_ORD, CI->getArgOperand(0),
+ RHSC);
+ // fabs(x) == 0 --> x == 0
+ // fabs(x) != 0 --> x != 0
+ case FCmpInst::FCMP_OEQ:
+ case FCmpInst::FCMP_UEQ:
+ case FCmpInst::FCMP_ONE:
+ case FCmpInst::FCMP_UNE:
+ return new FCmpInst(I.getPredicate(), CI->getArgOperand(0),
+ RHSC);
+ }
+ }
+ }
+ }
}
}
projects / oota-llvm.git / blobdiff