aboutsummaryrefslogtreecommitdiff
path: root/llvm
diff options
context:
space:
mode:
Diffstat (limited to 'llvm')
-rw-r--r--llvm/include/llvm/Support/KnownBits.h4
-rw-r--r--llvm/lib/Analysis/ValueTracking.cpp46
-rw-r--r--llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp10
-rw-r--r--llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp5
-rw-r--r--llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp6
-rw-r--r--llvm/lib/Support/KnownBits.cpp16
-rw-r--r--llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp3
-rw-r--r--llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp2
-rw-r--r--llvm/lib/Target/ARM/ARMISelLowering.cpp3
-rw-r--r--llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp14
-rw-r--r--llvm/unittests/Support/KnownBitsTest.cpp6
11 files changed, 66 insertions, 49 deletions
diff --git a/llvm/include/llvm/Support/KnownBits.h b/llvm/include/llvm/Support/KnownBits.h
index 69c569b9..f5fce29 100644
--- a/llvm/include/llvm/Support/KnownBits.h
+++ b/llvm/include/llvm/Support/KnownBits.h
@@ -329,8 +329,8 @@ public:
const KnownBits &LHS, const KnownBits &RHS, const KnownBits &Carry);
/// Compute known bits resulting from adding LHS and RHS.
- static KnownBits computeForAddSub(bool Add, bool NSW, const KnownBits &LHS,
- KnownBits RHS);
+ static KnownBits computeForAddSub(bool Add, bool NSW, bool NUW,
+ const KnownBits &LHS, KnownBits RHS);
/// Compute known bits results from subtracting RHS from LHS with 1-bit
/// Borrow.
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 8d33b1c..9d78c5d 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -350,18 +350,19 @@ unsigned llvm::ComputeMaxSignificantBits(const Value *V, const DataLayout &DL,
}
static void computeKnownBitsAddSub(bool Add, const Value *Op0, const Value *Op1,
- bool NSW, const APInt &DemandedElts,
+ bool NSW, bool NUW,
+ const APInt &DemandedElts,
KnownBits &KnownOut, KnownBits &Known2,
unsigned Depth, const SimplifyQuery &Q) {
computeKnownBits(Op1, DemandedElts, KnownOut, Depth + 1, Q);
// If one operand is unknown and we have no nowrap information,
// the result will be unknown independently of the second operand.
- if (KnownOut.isUnknown() && !NSW)
+ if (KnownOut.isUnknown() && !NSW && !NUW)
return;
computeKnownBits(Op0, DemandedElts, Known2, Depth + 1, Q);
- KnownOut = KnownBits::computeForAddSub(Add, NSW, Known2, KnownOut);
+ KnownOut = KnownBits::computeForAddSub(Add, NSW, NUW, Known2, KnownOut);
}
static void computeKnownBitsMul(const Value *Op0, const Value *Op1, bool NSW,
@@ -1145,13 +1146,15 @@ static void computeKnownBitsFromOperator(const Operator *I,
}
case Instruction::Sub: {
bool NSW = Q.IIQ.hasNoSignedWrap(cast<OverflowingBinaryOperator>(I));
- computeKnownBitsAddSub(false, I->getOperand(0), I->getOperand(1), NSW,
+ bool NUW = Q.IIQ.hasNoUnsignedWrap(cast<OverflowingBinaryOperator>(I));
+ computeKnownBitsAddSub(false, I->getOperand(0), I->getOperand(1), NSW, NUW,
DemandedElts, Known, Known2, Depth, Q);
break;
}
case Instruction::Add: {
bool NSW = Q.IIQ.hasNoSignedWrap(cast<OverflowingBinaryOperator>(I));
- computeKnownBitsAddSub(true, I->getOperand(0), I->getOperand(1), NSW,
+ bool NUW = Q.IIQ.hasNoUnsignedWrap(cast<OverflowingBinaryOperator>(I));
+ computeKnownBitsAddSub(true, I->getOperand(0), I->getOperand(1), NSW, NUW,
DemandedElts, Known, Known2, Depth, Q);
break;
}
@@ -1245,12 +1248,12 @@ static void computeKnownBitsFromOperator(const Operator *I,
// Note that inbounds does *not* guarantee nsw for the addition, as only
// the offset is signed, while the base address is unsigned.
Known = KnownBits::computeForAddSub(
- /*Add=*/true, /*NSW=*/false, Known, IndexBits);
+ /*Add=*/true, /*NSW=*/false, /* NUW=*/false, Known, IndexBits);
}
if (!Known.isUnknown() && !AccConstIndices.isZero()) {
KnownBits Index = KnownBits::makeConstant(AccConstIndices);
Known = KnownBits::computeForAddSub(
- /*Add=*/true, /*NSW=*/false, Known, Index);
+ /*Add=*/true, /*NSW=*/false, /* NUW=*/false, Known, Index);
}
break;
}
@@ -1689,15 +1692,15 @@ static void computeKnownBitsFromOperator(const Operator *I,
default: break;
case Intrinsic::uadd_with_overflow:
case Intrinsic::sadd_with_overflow:
- computeKnownBitsAddSub(true, II->getArgOperand(0),
- II->getArgOperand(1), false, DemandedElts,
- Known, Known2, Depth, Q);
+ computeKnownBitsAddSub(
+ true, II->getArgOperand(0), II->getArgOperand(1), /*NSW=*/false,
+ /* NUW=*/false, DemandedElts, Known, Known2, Depth, Q);
break;
case Intrinsic::usub_with_overflow:
case Intrinsic::ssub_with_overflow:
- computeKnownBitsAddSub(false, II->getArgOperand(0),
- II->getArgOperand(1), false, DemandedElts,
- Known, Known2, Depth, Q);
+ computeKnownBitsAddSub(
+ false, II->getArgOperand(0), II->getArgOperand(1), /*NSW=*/false,
+ /* NUW=*/false, DemandedElts, Known, Known2, Depth, Q);
break;
case Intrinsic::umul_with_overflow:
case Intrinsic::smul_with_overflow:
@@ -2318,7 +2321,11 @@ static bool isNonZeroRecurrence(const PHINode *PN) {
static bool isNonZeroAdd(const APInt &DemandedElts, unsigned Depth,
const SimplifyQuery &Q, unsigned BitWidth, Value *X,
- Value *Y, bool NSW) {
+ Value *Y, bool NSW, bool NUW) {
+ if (NUW)
+ return isKnownNonZero(Y, DemandedElts, Depth, Q) ||
+ isKnownNonZero(X, DemandedElts, Depth, Q);
+
KnownBits XKnown = computeKnownBits(X, DemandedElts, Depth, Q);
KnownBits YKnown = computeKnownBits(Y, DemandedElts, Depth, Q);
@@ -2351,7 +2358,7 @@ static bool isNonZeroAdd(const APInt &DemandedElts, unsigned Depth,
isKnownToBeAPowerOfTwo(X, /*OrZero*/ false, Depth, Q))
return true;
- return KnownBits::computeForAddSub(/*Add*/ true, NSW, XKnown, YKnown)
+ return KnownBits::computeForAddSub(/*Add=*/true, NSW, NUW, XKnown, YKnown)
.isNonZero();
}
@@ -2556,12 +2563,9 @@ static bool isKnownNonZeroFromOperator(const Operator *I,
// If Add has nuw wrap flag, then if either X or Y is non-zero the result is
// non-zero.
auto *BO = cast<OverflowingBinaryOperator>(I);
- if (Q.IIQ.hasNoUnsignedWrap(BO))
- return isKnownNonZero(I->getOperand(1), DemandedElts, Depth, Q) ||
- isKnownNonZero(I->getOperand(0), DemandedElts, Depth, Q);
-
return isNonZeroAdd(DemandedElts, Depth, Q, BitWidth, I->getOperand(0),
- I->getOperand(1), Q.IIQ.hasNoSignedWrap(BO));
+ I->getOperand(1), Q.IIQ.hasNoSignedWrap(BO),
+ Q.IIQ.hasNoUnsignedWrap(BO));
}
case Instruction::Mul: {
// If X and Y are non-zero then so is X * Y as long as the multiplication
@@ -2716,7 +2720,7 @@ static bool isKnownNonZeroFromOperator(const Operator *I,
case Intrinsic::sadd_sat:
return isNonZeroAdd(DemandedElts, Depth, Q, BitWidth,
II->getArgOperand(0), II->getArgOperand(1),
- /*NSW*/ true);
+ /*NSW=*/true, /* NUW=*/false);
case Intrinsic::umax:
case Intrinsic::uadd_sat:
return isKnownNonZero(II->getArgOperand(1), DemandedElts, Depth, Q) ||
diff --git a/llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp b/llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp
index ea8c20c..099bf45 100644
--- a/llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp
@@ -269,8 +269,8 @@ void GISelKnownBits::computeKnownBitsImpl(Register R, KnownBits &Known,
Depth + 1);
computeKnownBitsImpl(MI.getOperand(2).getReg(), Known2, DemandedElts,
Depth + 1);
- Known = KnownBits::computeForAddSub(/*Add*/ false, /*NSW*/ false, Known,
- Known2);
+ Known = KnownBits::computeForAddSub(/*Add=*/false, /*NSW=*/false,
+ /* NUW=*/false, Known, Known2);
break;
}
case TargetOpcode::G_XOR: {
@@ -296,8 +296,8 @@ void GISelKnownBits::computeKnownBitsImpl(Register R, KnownBits &Known,
Depth + 1);
computeKnownBitsImpl(MI.getOperand(2).getReg(), Known2, DemandedElts,
Depth + 1);
- Known =
- KnownBits::computeForAddSub(/*Add*/ true, /*NSW*/ false, Known, Known2);
+ Known = KnownBits::computeForAddSub(/*Add=*/true, /*NSW=*/false,
+ /* NUW=*/false, Known, Known2);
break;
}
case TargetOpcode::G_AND: {
@@ -564,7 +564,7 @@ void GISelKnownBits::computeKnownBitsImpl(Register R, KnownBits &Known,
// right.
KnownBits ExtKnown = KnownBits::makeConstant(APInt(BitWidth, BitWidth));
KnownBits ShiftKnown = KnownBits::computeForAddSub(
- /*Add*/ false, /*NSW*/ false, ExtKnown, WidthKnown);
+ /*Add=*/false, /*NSW=*/false, /* NUW=*/false, ExtKnown, WidthKnown);
Known = KnownBits::ashr(KnownBits::shl(Known, ShiftKnown), ShiftKnown);
break;
}
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 5b1b7c7c..f7ace79 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3763,8 +3763,9 @@ KnownBits SelectionDAG::computeKnownBits(SDValue Op, const APInt &DemandedElts,
SDNodeFlags Flags = Op.getNode()->getFlags();
Known = computeKnownBits(Op.getOperand(0), DemandedElts, Depth + 1);
Known2 = computeKnownBits(Op.getOperand(1), DemandedElts, Depth + 1);
- Known = KnownBits::computeForAddSub(Op.getOpcode() == ISD::ADD,
- Flags.hasNoSignedWrap(), Known, Known2);
+ Known = KnownBits::computeForAddSub(
+ Op.getOpcode() == ISD::ADD, Flags.hasNoSignedWrap(),
+ Flags.hasNoUnsignedWrap(), Known, Known2);
break;
}
case ISD::USUBO:
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 6970b23..a639cba 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -2876,9 +2876,9 @@ bool TargetLowering::SimplifyDemandedBits(
if (Op.getOpcode() == ISD::MUL) {
Known = KnownBits::mul(KnownOp0, KnownOp1);
} else { // Op.getOpcode() is either ISD::ADD or ISD::SUB.
- Known = KnownBits::computeForAddSub(Op.getOpcode() == ISD::ADD,
- Flags.hasNoSignedWrap(), KnownOp0,
- KnownOp1);
+ Known = KnownBits::computeForAddSub(
+ Op.getOpcode() == ISD::ADD, Flags.hasNoSignedWrap(),
+ Flags.hasNoUnsignedWrap(), KnownOp0, KnownOp1);
}
break;
}
diff --git a/llvm/lib/Support/KnownBits.cpp b/llvm/lib/Support/KnownBits.cpp
index c44a08c..f999abe 100644
--- a/llvm/lib/Support/KnownBits.cpp
+++ b/llvm/lib/Support/KnownBits.cpp
@@ -54,7 +54,7 @@ KnownBits KnownBits::computeForAddCarry(
LHS, RHS, Carry.Zero.getBoolValue(), Carry.One.getBoolValue());
}
-KnownBits KnownBits::computeForAddSub(bool Add, bool NSW,
+KnownBits KnownBits::computeForAddSub(bool Add, bool NSW, bool /*NUW*/,
const KnownBits &LHS, KnownBits RHS) {
KnownBits KnownOut;
if (Add) {
@@ -180,11 +180,14 @@ KnownBits KnownBits::absdiff(const KnownBits &LHS, const KnownBits &RHS) {
// absdiff(LHS,RHS) = sub(umax(LHS,RHS), umin(LHS,RHS)).
KnownBits UMaxValue = umax(LHS, RHS);
KnownBits UMinValue = umin(LHS, RHS);
- KnownBits MinMaxDiff = computeForAddSub(false, false, UMaxValue, UMinValue);
+ KnownBits MinMaxDiff = computeForAddSub(/*Add=*/false, /*NSW=*/false,
+ /*NUW=*/true, UMaxValue, UMinValue);
// find the common bits between sub(LHS,RHS) and sub(RHS,LHS).
- KnownBits Diff0 = computeForAddSub(false, false, LHS, RHS);
- KnownBits Diff1 = computeForAddSub(false, false, RHS, LHS);
+ KnownBits Diff0 =
+ computeForAddSub(/*Add=*/false, /*NSW=*/false, /*NUW=*/false, LHS, RHS);
+ KnownBits Diff1 =
+ computeForAddSub(/*Add=*/false, /*NSW=*/false, /*NUW=*/false, RHS, LHS);
KnownBits SubDiff = Diff0.intersectWith(Diff1);
KnownBits KnownAbsDiff = MinMaxDiff.unionWith(SubDiff);
@@ -459,7 +462,7 @@ KnownBits KnownBits::abs(bool IntMinIsPoison) const {
Tmp.One.setBit(countMinTrailingZeros());
KnownAbs = computeForAddSub(
- /*Add*/ false, IntMinIsPoison,
+ /*Add*/ false, IntMinIsPoison, /*NUW=*/false,
KnownBits::makeConstant(APInt(getBitWidth(), 0)), Tmp);
// One more special case for IntMinIsPoison. If we don't know any ones other
@@ -505,7 +508,8 @@ static KnownBits computeForSatAddSub(bool Add, bool Signed,
assert(!LHS.hasConflict() && !RHS.hasConflict() && "Bad inputs");
// We don't see NSW even for sadd/ssub as we want to check if the result has
// signed overflow.
- KnownBits Res = KnownBits::computeForAddSub(Add, /*NSW*/ false, LHS, RHS);
+ KnownBits Res =
+ KnownBits::computeForAddSub(Add, /*NSW=*/false, /*NUW=*/false, LHS, RHS);
unsigned BitWidth = Res.getBitWidth();
auto SignBitKnown = [&](const KnownBits &K) {
return K.Zero[BitWidth - 1] || K.One[BitWidth - 1];
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp b/llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
index 4896ae8..2e5b02f 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp
@@ -1903,7 +1903,8 @@ bool AMDGPUDAGToDAGISel::checkFlatScratchSVSSwizzleBug(
// voffset to (soffset + inst_offset).
KnownBits VKnown = CurDAG->computeKnownBits(VAddr);
KnownBits SKnown = KnownBits::computeForAddSub(
- true, false, CurDAG->computeKnownBits(SAddr),
+ /*Add=*/true, /*NSW=*/false, /*NUW=*/false,
+ CurDAG->computeKnownBits(SAddr),
KnownBits::makeConstant(APInt(32, ImmOffset)));
uint64_t VMax = VKnown.getMaxValue().getZExtValue();
uint64_t SMax = SKnown.getMaxValue().getZExtValue();
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
index b2c65e6..94cc1d9 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
@@ -4573,7 +4573,7 @@ bool AMDGPUInstructionSelector::checkFlatScratchSVSSwizzleBug(
// voffset to (soffset + inst_offset).
auto VKnown = KB->getKnownBits(VAddr);
auto SKnown = KnownBits::computeForAddSub(
- true, false, KB->getKnownBits(SAddr),
+ /*Add=*/true, /*NSW=*/false, /*NUW=*/false, KB->getKnownBits(SAddr),
KnownBits::makeConstant(APInt(32, ImmOffset)));
uint64_t VMax = VKnown.getMaxValue().getZExtValue();
uint64_t SMax = SKnown.getMaxValue().getZExtValue();
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 06d4a39c..dc81178 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -20154,7 +20154,8 @@ void ARMTargetLowering::computeKnownBitsForTargetNode(const SDValue Op,
// CSNEG: KnownOp0 or KnownOp1 * -1
if (Op.getOpcode() == ARMISD::CSINC)
KnownOp1 = KnownBits::computeForAddSub(
- true, false, KnownOp1, KnownBits::makeConstant(APInt(32, 1)));
+ /*Add=*/true, /*NSW=*/false, /*NUW=*/false, KnownOp1,
+ KnownBits::makeConstant(APInt(32, 1)));
else if (Op.getOpcode() == ARMISD::CSINV)
std::swap(KnownOp1.Zero, KnownOp1.One);
else if (Op.getOpcode() == ARMISD::CSNEG)
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index 97ae980..1b963a7 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -565,7 +565,8 @@ Value *InstCombinerImpl::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
// Otherwise just compute the known bits of the result.
bool NSW = cast<OverflowingBinaryOperator>(I)->hasNoSignedWrap();
- Known = KnownBits::computeForAddSub(true, NSW, LHSKnown, RHSKnown);
+ bool NUW = cast<OverflowingBinaryOperator>(I)->hasNoUnsignedWrap();
+ Known = KnownBits::computeForAddSub(true, NSW, NUW, LHSKnown, RHSKnown);
break;
}
case Instruction::Sub: {
@@ -598,7 +599,8 @@ Value *InstCombinerImpl::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
// Otherwise just compute the known bits of the result.
bool NSW = cast<OverflowingBinaryOperator>(I)->hasNoSignedWrap();
- Known = KnownBits::computeForAddSub(false, NSW, LHSKnown, RHSKnown);
+ bool NUW = cast<OverflowingBinaryOperator>(I)->hasNoUnsignedWrap();
+ Known = KnownBits::computeForAddSub(false, NSW, NUW, LHSKnown, RHSKnown);
break;
}
case Instruction::Mul: {
@@ -1206,7 +1208,9 @@ Value *InstCombinerImpl::SimplifyMultipleUseDemandedBits(
return I->getOperand(1);
bool NSW = cast<OverflowingBinaryOperator>(I)->hasNoSignedWrap();
- Known = KnownBits::computeForAddSub(/*Add*/ true, NSW, LHSKnown, RHSKnown);
+ bool NUW = cast<OverflowingBinaryOperator>(I)->hasNoUnsignedWrap();
+ Known =
+ KnownBits::computeForAddSub(/*Add=*/true, NSW, NUW, LHSKnown, RHSKnown);
computeKnownBitsFromContext(I, Known, Depth, SQ.getWithInstruction(CxtI));
break;
}
@@ -1221,8 +1225,10 @@ Value *InstCombinerImpl::SimplifyMultipleUseDemandedBits(
return I->getOperand(0);
bool NSW = cast<OverflowingBinaryOperator>(I)->hasNoSignedWrap();
+ bool NUW = cast<OverflowingBinaryOperator>(I)->hasNoUnsignedWrap();
computeKnownBits(I->getOperand(0), LHSKnown, Depth + 1, CxtI);
- Known = KnownBits::computeForAddSub(/*Add*/ false, NSW, LHSKnown, RHSKnown);
+ Known = KnownBits::computeForAddSub(/*Add=*/false, NSW, NUW, LHSKnown,
+ RHSKnown);
computeKnownBitsFromContext(I, Known, Depth, SQ.getWithInstruction(CxtI));
break;
}
diff --git a/llvm/unittests/Support/KnownBitsTest.cpp b/llvm/unittests/Support/KnownBitsTest.cpp
index fb9210b..d0ea1095 100644
--- a/llvm/unittests/Support/KnownBitsTest.cpp
+++ b/llvm/unittests/Support/KnownBitsTest.cpp
@@ -194,14 +194,14 @@ static void TestAddSubExhaustive(bool IsAdd) {
});
});
- KnownBits KnownComputed =
- KnownBits::computeForAddSub(IsAdd, /*NSW*/ false, Known1, Known2);
+ KnownBits KnownComputed = KnownBits::computeForAddSub(
+ IsAdd, /*NSW=*/false, /*NUW=*/false, Known1, Known2);
EXPECT_EQ(Known, KnownComputed);
// The NSW calculation is not precise, only check that it's
// conservatively correct.
KnownBits KnownNSWComputed = KnownBits::computeForAddSub(
- IsAdd, /*NSW*/true, Known1, Known2);
+ IsAdd, /*NSW=*/true, /*NUW=*/false, Known1, Known2);
EXPECT_TRUE(KnownNSWComputed.Zero.isSubsetOf(KnownNSW.Zero));
EXPECT_TRUE(KnownNSWComputed.One.isSubsetOf(KnownNSW.One));
});
generated by cgit v1.1 at 2025-08-03 08:39:32 +0000