[llvm] [ValueTracking] Use `SimplifyQuery` in `isKnownNonEqual` (PR #124942)
Yingwei Zheng via llvm-commits
llvm-commits at lists.llvm.org
Wed Jan 29 08:38:12 PST 2025
https://github.com/dtcxzyw created https://github.com/llvm/llvm-project/pull/124942
It is needed by https://github.com/llvm/llvm-project/pull/117442.
>From 177b4a83efb12ae1147d05aeee1baebaf6495581 Mon Sep 17 00:00:00 2001
From: Yingwei Zheng <dtcxzyw2333 at gmail.com>
Date: Thu, 30 Jan 2025 00:36:25 +0800
Subject: [PATCH] [ValueTracking] Use `SimplifyQuery` in `isKnownNonEqual`
---
llvm/include/llvm/Analysis/ValueTracking.h | 7 ++-----
llvm/lib/Analysis/BasicAliasAnalysis.cpp | 4 ++--
llvm/lib/Analysis/InstructionSimplify.cpp | 2 +-
llvm/lib/Analysis/ValueTracking.cpp | 9 +++------
llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 2 +-
llvm/test/Transforms/InstCombine/known-bits.ll | 6 +-----
6 files changed, 10 insertions(+), 20 deletions(-)
diff --git a/llvm/include/llvm/Analysis/ValueTracking.h b/llvm/include/llvm/Analysis/ValueTracking.h
index b4918c2d1e8a18..dba54be4c92f83 100644
--- a/llvm/include/llvm/Analysis/ValueTracking.h
+++ b/llvm/include/llvm/Analysis/ValueTracking.h
@@ -164,11 +164,8 @@ bool isKnownNegative(const Value *V, const SimplifyQuery &SQ,
/// Return true if the given values are known to be non-equal when defined.
/// Supports scalar integer types only.
-bool isKnownNonEqual(const Value *V1, const Value *V2, const DataLayout &DL,
- AssumptionCache *AC = nullptr,
- const Instruction *CxtI = nullptr,
- const DominatorTree *DT = nullptr,
- bool UseInstrInfo = true);
+bool isKnownNonEqual(const Value *V1, const Value *V2, const SimplifyQuery &SQ,
+ unsigned Depth = 0);
/// Return true if 'V & Mask' is known to be zero. We use this predicate to
/// simplify operations downstream. Mask is known to be zero for bits that V
diff --git a/llvm/lib/Analysis/BasicAliasAnalysis.cpp b/llvm/lib/Analysis/BasicAliasAnalysis.cpp
index b2a3f3390e000d..893a8f7c1207b4 100644
--- a/llvm/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/llvm/lib/Analysis/BasicAliasAnalysis.cpp
@@ -1349,8 +1349,8 @@ AliasResult BasicAAResult::aliasGEP(
const VariableGEPIndex &Var1 = DecompGEP1.VarIndices[1];
if (Var0.hasNegatedScaleOf(Var1) && Var0.Val.TruncBits == 0 &&
Var0.Val.hasSameCastsAs(Var1.Val) && !AAQI.MayBeCrossIteration &&
- isKnownNonEqual(Var0.Val.V, Var1.Val.V, DL, &AC, /* CxtI */ nullptr,
- DT))
+ isKnownNonEqual(Var0.Val.V, Var1.Val.V,
+ SimplifyQuery(DL, DT, &AC, /*CxtI=*/nullptr)))
MinAbsVarIndex = Var0.Scale.abs();
}
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index d69747e30f884d..f76bfa9c5d58c5 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -3994,7 +3994,7 @@ static Value *simplifyICmpInst(CmpPredicate Pred, Value *LHS, Value *RHS,
// This is potentially expensive, and we have already computedKnownBits for
// compares with 0 above here, so only try this for a non-zero compare.
if (ICmpInst::isEquality(Pred) && !match(RHS, m_Zero()) &&
- isKnownNonEqual(LHS, RHS, Q.DL, Q.AC, Q.CxtI, Q.DT, Q.IIQ.UseInstrInfo)) {
+ isKnownNonEqual(LHS, RHS, Q)) {
return Pred == ICmpInst::ICMP_NE ? getTrue(ITy) : getFalse(ITy);
}
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index b63a0a07f7de29..649581741e0e24 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -316,18 +316,15 @@ static bool isKnownNonEqual(const Value *V1, const Value *V2,
const SimplifyQuery &Q);
bool llvm::isKnownNonEqual(const Value *V1, const Value *V2,
- const DataLayout &DL, AssumptionCache *AC,
- const Instruction *CxtI, const DominatorTree *DT,
- bool UseInstrInfo) {
+ const SimplifyQuery &Q, unsigned Depth) {
// We don't support looking through casts.
if (V1 == V2 || V1->getType() != V2->getType())
return false;
auto *FVTy = dyn_cast<FixedVectorType>(V1->getType());
APInt DemandedElts =
FVTy ? APInt::getAllOnes(FVTy->getNumElements()) : APInt(1, 1);
- return ::isKnownNonEqual(
- V1, V2, DemandedElts, 0,
- SimplifyQuery(DL, DT, AC, safeCxtI(V2, V1, CxtI), UseInstrInfo));
+ return ::isKnownNonEqual(V1, V2, DemandedElts, Depth,
+ Q.getWithInstruction(safeCxtI(V2, V1, Q.CxtI)));
}
bool llvm::MaskedValueIsZero(const Value *V, const APInt &Mask,
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 5a4791870ac77b..a7e70cf09d2393 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -5412,7 +5412,7 @@ Instruction *InstCombinerImpl::foldICmpBinOp(ICmpInst &I,
if (ICmpInst::isEquality(Pred)) {
// If X != Y, fold (X *nw Z) eq/ne (Y *nw Z) -> Z eq/ne 0
if (((Op0HasNSW && Op1HasNSW) || (Op0HasNUW && Op1HasNUW)) &&
- isKnownNonEqual(X, Y, DL, &AC, &I, &DT))
+ isKnownNonEqual(X, Y, SQ))
return new ICmpInst(Pred, Z, Constant::getNullValue(Z->getType()));
KnownBits ZKnown = computeKnownBits(Z, 0, &I);
diff --git a/llvm/test/Transforms/InstCombine/known-bits.ll b/llvm/test/Transforms/InstCombine/known-bits.ll
index 9467f507cd6306..bd6b2f015145e5 100644
--- a/llvm/test/Transforms/InstCombine/known-bits.ll
+++ b/llvm/test/Transforms/InstCombine/known-bits.ll
@@ -1609,17 +1609,13 @@ if.else:
ret i16 0
}
-; TODO: %cmp always evaluates to false
-
define i1 @test_simplify_icmp2(double %x) {
; CHECK-LABEL: @test_simplify_icmp2(
; CHECK-NEXT: [[ABS:%.*]] = tail call double @llvm.fabs.f64(double [[X:%.*]])
; CHECK-NEXT: [[COND:%.*]] = fcmp oeq double [[ABS]], 0x7FF0000000000000
; CHECK-NEXT: br i1 [[COND]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
; CHECK: if.then:
-; CHECK-NEXT: [[CAST:%.*]] = bitcast double [[X]] to i64
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq i64 [[CAST]], 3458764513820540928
-; CHECK-NEXT: ret i1 [[CMP]]
+; CHECK-NEXT: ret i1 false
; CHECK: if.else:
; CHECK-NEXT: ret i1 false
;
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