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Merged
merged 4 commits into from
Apr 21, 2017
Merged

Performance improvements for new integers #8897

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315b2ab
[sil-combine] Canonicalize boolean equality checks
swiftix Apr 8, 2017
616ef49
[sil-combine] Handle more patterns in cond_br conditions
swiftix Apr 8, 2017
2326cb7
[constant-propagation] Simplify comparisons with Int.max
swiftix Apr 8, 2017
e1c3538
redundundant-overflow-check-removal improvements
swiftix Apr 8, 2017
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127 changes: 127 additions & 0 deletions lib/SILOptimizer/Mandatory/ConstantPropagation.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -232,6 +232,7 @@ static SILInstruction *constantFoldCompare(BuiltinInst *BI,
return B.createIntegerLiteral(BI->getLoc(), BI->getType(), Res);
}

// Comparisons of an unsigned value with 0.
SILValue Other;
auto MatchNonNegative =
m_BuiltinInst(BuiltinValueKind::AssumeNonNegative, m_ValueBase());
Expand Down Expand Up @@ -259,6 +260,132 @@ static SILInstruction *constantFoldCompare(BuiltinInst *BI,
return B.createIntegerLiteral(BI->getLoc(), BI->getType(), APInt(1, 1));
}

// Comparisons with Int.Max.
IntegerLiteralInst *IntMax;

// Check signed comparisons.
if (match(BI,
m_CombineOr(
// Int.max < x
m_BuiltinInst(BuiltinValueKind::ICMP_SLT,
m_IntegerLiteralInst(IntMax), m_SILValue(Other)),
// x > Int.max
m_BuiltinInst(BuiltinValueKind::ICMP_SGT, m_SILValue(Other),
m_IntegerLiteralInst(IntMax)))) &&
IntMax->getValue().isMaxSignedValue()) {
// Any signed number should be <= then IntMax.
SILBuilderWithScope B(BI);
return B.createIntegerLiteral(BI->getLoc(), BI->getType(), APInt());
}

if (match(BI,
m_CombineOr(
m_BuiltinInst(BuiltinValueKind::ICMP_SGE,
m_IntegerLiteralInst(IntMax), m_SILValue(Other)),
m_BuiltinInst(BuiltinValueKind::ICMP_SLE, m_SILValue(Other),
m_IntegerLiteralInst(IntMax)))) &&
IntMax->getValue().isMaxSignedValue()) {
// Any signed number should be <= then IntMax.
SILBuilderWithScope B(BI);
return B.createIntegerLiteral(BI->getLoc(), BI->getType(), APInt(1, 1));
}

// For any x of the same size as Int.max and n>=1 , (x>>n) is always <= Int.max,
// that is (x>>n) <= Int.max and Int.max >= (x>>n) are true.
if (match(BI,
m_CombineOr(
// Int.max >= x
m_BuiltinInst(BuiltinValueKind::ICMP_UGE,
m_IntegerLiteralInst(IntMax), m_SILValue(Other)),
// x <= Int.max
m_BuiltinInst(BuiltinValueKind::ICMP_ULE, m_SILValue(Other),
m_IntegerLiteralInst(IntMax)),
// Int.max >= x
m_BuiltinInst(BuiltinValueKind::ICMP_SGE,
m_IntegerLiteralInst(IntMax), m_SILValue(Other)),
// x <= Int.max
m_BuiltinInst(BuiltinValueKind::ICMP_SLE, m_SILValue(Other),
m_IntegerLiteralInst(IntMax)))) &&
IntMax->getValue().isMaxSignedValue()) {
// Check if other is a result of a logical shift right by a strictly
// positive number of bits.
IntegerLiteralInst *ShiftCount;
if (match(Other, m_BuiltinInst(BuiltinValueKind::LShr, m_ValueBase(),
m_IntegerLiteralInst(ShiftCount))) &&
ShiftCount->getValue().isStrictlyPositive()) {
SILBuilderWithScope B(BI);
return B.createIntegerLiteral(BI->getLoc(), BI->getType(), APInt(1, 1));
}
}

// At the same time (x>>n) > Int.max and Int.max < (x>>n) is false.
if (match(BI,
m_CombineOr(
// Int.max < x
m_BuiltinInst(BuiltinValueKind::ICMP_ULT,
m_IntegerLiteralInst(IntMax), m_SILValue(Other)),
// x > Int.max
m_BuiltinInst(BuiltinValueKind::ICMP_UGT, m_SILValue(Other),
m_IntegerLiteralInst(IntMax)),
// Int.max < x
m_BuiltinInst(BuiltinValueKind::ICMP_SLT,
m_IntegerLiteralInst(IntMax), m_SILValue(Other)),
// x > Int.max
m_BuiltinInst(BuiltinValueKind::ICMP_SGT, m_SILValue(Other),
m_IntegerLiteralInst(IntMax)))) &&
IntMax->getValue().isMaxSignedValue()) {
// Check if other is a result of a logical shift right by a strictly
// positive number of bits.
IntegerLiteralInst *ShiftCount;
if (match(Other, m_BuiltinInst(BuiltinValueKind::LShr, m_ValueBase(),
m_IntegerLiteralInst(ShiftCount))) &&
ShiftCount->getValue().isStrictlyPositive()) {
SILBuilderWithScope B(BI);
return B.createIntegerLiteral(BI->getLoc(), BI->getType(), APInt());
}
}

// Fold x < 0 into false, if x is known to be a result of an unsigned
// operation with overflow checks enabled.
BuiltinInst *BIOp;
if (match(BI, m_BuiltinInst(BuiltinValueKind::ICMP_SLT,
m_TupleExtractInst(m_BuiltinInst(BIOp), 0),
m_Zero()))) {
// Check if Other is a result of an unsigned operation with overflow.
switch (BIOp->getBuiltinInfo().ID) {
default:
break;
case BuiltinValueKind::UAddOver:
case BuiltinValueKind::USubOver:
case BuiltinValueKind::UMulOver:
// Was it an operation with an overflow check?
if (match(BIOp->getOperand(2), m_One())) {
SILBuilderWithScope B(BI);
return B.createIntegerLiteral(BI->getLoc(), BI->getType(), APInt());
}
}
}

// Fold x >= 0 into true, if x is known to be a result of an unsigned
// operation with overflow checks enabled.
if (match(BI, m_BuiltinInst(BuiltinValueKind::ICMP_SGE,
m_TupleExtractInst(m_BuiltinInst(BIOp), 0),
m_Zero()))) {
// Check if Other is a result of an unsigned operation with overflow.
switch (BIOp->getBuiltinInfo().ID) {
default:
break;
case BuiltinValueKind::UAddOver:
case BuiltinValueKind::USubOver:
case BuiltinValueKind::UMulOver:
// Was it an operation with an overflow check?
if (match(BIOp->getOperand(2), m_One())) {
SILBuilderWithScope B(BI);
return B.createIntegerLiteral(BI->getLoc(), BI->getType(), APInt(1, 1));
}
}
}

return nullptr;
}

Expand Down
13 changes: 12 additions & 1 deletion lib/SILOptimizer/SILCombiner/SILCombinerBuiltinVisitors.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -55,8 +55,19 @@ SILInstruction *SILCombiner::optimizeBuiltinCompareEq(BuiltinInst *BI,
IsZeroKind RHS = isZeroValue(BI->getArguments()[1]);

// Can't handle unknown values.
if (LHS == IsZeroKind::Unknown || RHS == IsZeroKind::Unknown)
if (LHS == IsZeroKind::Unknown) {
return nullptr;
}

// Canonicalize i1_const == X to X == i1_const.
// Canonicalize i1_const != X to X != i1_const.
if (RHS == IsZeroKind::Unknown) {
auto *CanonI =
Builder.createBuiltin(BI->getLoc(), BI->getName(), BI->getType(), {},
{BI->getArguments()[1], BI->getArguments()[0]});
replaceInstUsesWith(*BI, CanonI);
return eraseInstFromFunction(*BI);
}

// Can't handle non-zero ptr values.
if (LHS == IsZeroKind::NotZero && RHS == IsZeroKind::NotZero)
Expand Down
17 changes: 15 additions & 2 deletions lib/SILOptimizer/SILCombiner/SILCombinerMiscVisitors.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1075,9 +1075,22 @@ SILInstruction *SILCombiner::visitStrongReleaseInst(StrongReleaseInst *SRI) {

SILInstruction *SILCombiner::visitCondBranchInst(CondBranchInst *CBI) {
// cond_br(xor(x, 1)), t_label, f_label -> cond_br x, f_label, t_label
// cond_br(x == 0), t_label, f_label -> cond_br x, f_label, t_label
// cond_br(x != 1), t_label, f_label -> cond_br x, f_label, t_label
SILValue X;
if (match(CBI->getCondition(), m_ApplyInst(BuiltinValueKind::Xor,
m_SILValue(X), m_One()))) {
if (match(CBI->getCondition(),
m_CombineOr(
// xor(x, 1)
m_ApplyInst(BuiltinValueKind::Xor, m_SILValue(X), m_One()),
// xor(1,x)
m_ApplyInst(BuiltinValueKind::Xor, m_One(), m_SILValue(X)),
// x == 0
m_ApplyInst(BuiltinValueKind::ICMP_EQ, m_SILValue(X), m_Zero()),
// x != 1
m_ApplyInst(BuiltinValueKind::ICMP_NE, m_SILValue(X),
m_One()))) &&
X->getType() ==
SILType::getBuiltinIntegerType(1, CBI->getModule().getASTContext())) {
SmallVector<SILValue, 4> OrigTrueArgs, OrigFalseArgs;
for (const auto &Op : CBI->getTrueArgs())
OrigTrueArgs.push_back(Op);
Expand Down
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