[llvm] 0aabdad - [InstCombine] Combine code for and/or of icmps (NFC)
Nikita Popov via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 9 12:18:40 PST 2021
Author: Nikita Popov
Date: 2021-11-09T21:18:31+01:00
New Revision: 0aabdad1ef96d489d63933e47bf19bcc832239e8
URL: https://github.com/llvm/llvm-project/commit/0aabdad1ef96d489d63933e47bf19bcc832239e8
DIFF: https://github.com/llvm/llvm-project/commit/0aabdad1ef96d489d63933e47bf19bcc832239e8.diff
LOG: [InstCombine] Combine code for and/or of icmps (NFC)
The implementation for and/or is the same, apart from the choice
of exactIntersectWith() vs exactUnionWith(). Extract a common
function to make future extension easier.
Added:
Modified:
llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index fbda801e73e7..9b9b0c0c9af3 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1199,6 +1199,34 @@ static Value *foldAndOrOfICmpsWithConstEq(ICmpInst *Cmp0, ICmpInst *Cmp1,
return Builder.CreateBinOp(Logic.getOpcode(), Cmp0, SubstituteCmp);
}
+/// Fold (icmp Pred1 V1, C1) & (icmp Pred2 V2, C2)
+/// or (icmp Pred1 V1, C1) | (icmp Pred2 V2, C2)
+/// into a single comparison using range-based reasoning.
+static Value *foldAndOrOfICmpsUsingRanges(
+ ICmpInst::Predicate Pred1, Value *V1, const APInt &C1,
+ ICmpInst::Predicate Pred2, Value *V2, const APInt &C2,
+ IRBuilderBase &Builder, bool IsAnd) {
+ if (V1 != V2)
+ return nullptr;
+
+ ConstantRange CR1 = ConstantRange::makeExactICmpRegion(Pred1, C1);
+ ConstantRange CR2 = ConstantRange::makeExactICmpRegion(Pred2, C2);
+ Optional<ConstantRange> CR =
+ IsAnd ? CR1.exactIntersectWith(CR2) : CR1.exactUnionWith(CR2);
+ if (!CR)
+ return nullptr;
+
+ CmpInst::Predicate NewPred;
+ APInt NewC, Offset;
+ CR->getEquivalentICmp(NewPred, NewC, Offset);
+
+ Type *Ty = V1->getType();
+ Value *NewV = V1;
+ if (Offset != 0)
+ NewV = Builder.CreateAdd(NewV, ConstantInt::get(Ty, Offset));
+ return Builder.CreateICmp(NewPred, NewV, ConstantInt::get(Ty, NewC));
+}
+
/// Fold (icmp)&(icmp) if possible.
Value *InstCombinerImpl::foldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS,
BinaryOperator &And) {
@@ -1317,28 +1345,9 @@ Value *InstCombinerImpl::foldAndOfICmps(ICmpInst *LHS, ICmpInst *RHS,
}
}
- // From here on, we only handle:
- // (icmp1 A, C1) & (icmp2 A, C2) --> something simpler.
- if (LHS0 != RHS0)
- return nullptr;
-
- ConstantRange CR1 =
- ConstantRange::makeExactICmpRegion(PredL, LHSC->getValue());
- ConstantRange CR2 =
- ConstantRange::makeExactICmpRegion(PredR, RHSC->getValue());
- Optional<ConstantRange> CR = CR1.exactIntersectWith(CR2);
- if (!CR)
- return nullptr;
-
- CmpInst::Predicate Pred;
- APInt NewRHS, Offset;
- CR->getEquivalentICmp(Pred, NewRHS, Offset);
-
- Type *Ty = LHS0->getType();
- Value *NewLHS = LHS0;
- if (Offset != 0)
- NewLHS = Builder.CreateAdd(NewLHS, ConstantInt::get(Ty, Offset));
- return Builder.CreateICmp(Pred, NewLHS, ConstantInt::get(Ty, NewRHS));
+ return foldAndOrOfICmpsUsingRanges(PredL, LHS0, LHSC->getValue(),
+ PredR, RHS0, RHSC->getValue(),
+ Builder, /* IsAnd */ true);
}
Value *InstCombinerImpl::foldLogicOfFCmps(FCmpInst *LHS, FCmpInst *RHS,
@@ -2462,28 +2471,9 @@ Value *InstCombinerImpl::foldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS,
return Builder.CreateICmpULE(LHS0, LHSC);
}
- // From here on, we only handle:
- // (icmp1 A, C1) | (icmp2 A, C2) --> something simpler.
- if (LHS0 != RHS0)
- return nullptr;
-
- ConstantRange CR1 =
- ConstantRange::makeExactICmpRegion(PredL, LHSC->getValue());
- ConstantRange CR2 =
- ConstantRange::makeExactICmpRegion(PredR, RHSC->getValue());
- Optional<ConstantRange> CR = CR1.exactUnionWith(CR2);
- if (!CR)
- return nullptr;
-
- CmpInst::Predicate Pred;
- APInt NewRHS, Offset;
- CR->getEquivalentICmp(Pred, NewRHS, Offset);
-
- Type *Ty = LHS0->getType();
- Value *NewLHS = LHS0;
- if (Offset != 0)
- NewLHS = Builder.CreateAdd(NewLHS, ConstantInt::get(Ty, Offset));
- return Builder.CreateICmp(Pred, NewLHS, ConstantInt::get(Ty, NewRHS));
+ return foldAndOrOfICmpsUsingRanges(PredL, LHS0, LHSC->getValue(),
+ PredR, RHS0, RHSC->getValue(),
+ Builder, /* IsAnd */ false);
}
// FIXME: We use commutative matchers (m_c_*) for some, but not all, matches
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