[llvm] [DA] Simplify runtime predicate collection and extend to all dependence tests (PR #157523)
Sebastian Pop via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 25 11:19:47 PST 2025
https://github.com/sebpop updated https://github.com/llvm/llvm-project/pull/157523
>From 711843055667e81724e3f5468c40633cda6fb20b Mon Sep 17 00:00:00 2001
From: Sebastian Pop <spop at nvidia.com>
Date: Tue, 25 Nov 2025 13:59:49 -0500
Subject: [PATCH] [DA] Simplify runtime predicate collection
Removes DependenceInfo::getRuntimeAssumptions(), DependenceInfo::Assumptions,
and the print of "Runtime Assumptions:". The runtime assumptions are still
properly attached to each Dependence result and printed as part of the
per-dependence output.
---
.../llvm/Analysis/DependenceAnalysis.h | 5 ----
llvm/lib/Analysis/DependenceAnalysis.cpp | 27 +++----------------
.../DependenceAnalysis/DifferentOffsets.ll | 7 -----
.../DependenceAnalysis/MIVCheckConst.ll | 3 ---
4 files changed, 4 insertions(+), 38 deletions(-)
diff --git a/llvm/include/llvm/Analysis/DependenceAnalysis.h b/llvm/include/llvm/Analysis/DependenceAnalysis.h
index f603ae8dbd70f..a39a9d4b66442 100644
--- a/llvm/include/llvm/Analysis/DependenceAnalysis.h
+++ b/llvm/include/llvm/Analysis/DependenceAnalysis.h
@@ -355,16 +355,11 @@ class DependenceInfo {
Function *getFunction() const { return F; }
- /// getRuntimeAssumptions - Returns all the runtime assumptions under which
- /// the dependence test is valid.
- LLVM_ABI SCEVUnionPredicate getRuntimeAssumptions() const;
-
private:
AAResults *AA;
ScalarEvolution *SE;
LoopInfo *LI;
Function *F;
- SmallVector<const SCEVPredicate *, 4> Assumptions;
/// Subscript - This private struct represents a pair of subscripts from
/// a pair of potentially multi-dimensional array references. We use a
diff --git a/llvm/lib/Analysis/DependenceAnalysis.cpp b/llvm/lib/Analysis/DependenceAnalysis.cpp
index b0398fe7e93b3..5fc9614298c77 100644
--- a/llvm/lib/Analysis/DependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/DependenceAnalysis.cpp
@@ -441,11 +441,6 @@ static void dumpExampleDependence(raw_ostream &OS, DependenceInfo *DA,
}
}
}
- SCEVUnionPredicate Assumptions = DA->getRuntimeAssumptions();
- if (!Assumptions.isAlwaysTrue()) {
- OS << "Runtime Assumptions:\n";
- Assumptions.print(OS, 0);
- }
}
void DependenceAnalysisWrapperPass::print(raw_ostream &OS,
@@ -3510,10 +3505,6 @@ bool DependenceInfo::invalidate(Function &F, const PreservedAnalyses &PA,
Inv.invalidate<LoopAnalysis>(F, PA);
}
-SCEVUnionPredicate DependenceInfo::getRuntimeAssumptions() const {
- return SCEVUnionPredicate(Assumptions, *SE);
-}
-
// depends -
// Returns NULL if there is no dependence.
// Otherwise, return a Dependence with as many details as possible.
@@ -3614,20 +3605,10 @@ DependenceInfo::depends(Instruction *Src, Instruction *Dst,
SCEVUnionPredicate(Assume, *SE));
}
- if (!Assume.empty()) {
- if (!UnderRuntimeAssumptions)
- return std::make_unique<Dependence>(Src, Dst,
- SCEVUnionPredicate(Assume, *SE));
- // Add non-redundant assumptions.
- unsigned N = Assumptions.size();
- for (const SCEVPredicate *P : Assume) {
- bool Implied = false;
- for (unsigned I = 0; I != N && !Implied; I++)
- if (Assumptions[I]->implies(P, *SE))
- Implied = true;
- if (!Implied)
- Assumptions.push_back(P);
- }
+ if (!Assume.empty() && !UnderRuntimeAssumptions) {
+ // Runtime assumptions needed but not allowed.
+ return std::make_unique<Dependence>(Src, Dst,
+ SCEVUnionPredicate(Assume, *SE));
}
unsigned Pairs = 1;
diff --git a/llvm/test/Analysis/DependenceAnalysis/DifferentOffsets.ll b/llvm/test/Analysis/DependenceAnalysis/DifferentOffsets.ll
index 069a540ea0295..91d127cfc09d6 100644
--- a/llvm/test/Analysis/DependenceAnalysis/DifferentOffsets.ll
+++ b/llvm/test/Analysis/DependenceAnalysis/DifferentOffsets.ll
@@ -34,8 +34,6 @@ define i32 @alias_with_parametric_offset(ptr nocapture %A, i64 %n) {
; CHECK-NEXT: Equal predicate: (zext i2 (trunc i64 %n to i2) to i64) == 0
; CHECK-NEXT: Src: %0 = load i32, ptr %A, align 1 --> Dst: %0 = load i32, ptr %A, align 1
; CHECK-NEXT: da analyze - none!
-; CHECK-NEXT: Runtime Assumptions:
-; CHECK-NEXT: Equal predicate: (zext i2 (trunc i64 %n to i2) to i64) == 0
;
entry:
%arrayidx = getelementptr inbounds i8, ptr %A, i64 %n
@@ -55,9 +53,6 @@ define i32 @alias_with_parametric_expr(ptr nocapture %A, i64 %n, i64 %m) {
; CHECK-NEXT: Equal predicate: (zext i2 (-2 + (trunc i64 %m to i2)) to i64) == 0
; CHECK-NEXT: Src: %0 = load i32, ptr %arrayidx1, align 1 --> Dst: %0 = load i32, ptr %arrayidx1, align 1
; CHECK-NEXT: da analyze - none!
-; CHECK-NEXT: Runtime Assumptions:
-; CHECK-NEXT: Equal predicate: (zext i2 ((trunc i64 %m to i2) + (-2 * (trunc i64 %n to i2))) to i64) == 0
-; CHECK-NEXT: Equal predicate: (zext i2 (-2 + (trunc i64 %m to i2)) to i64) == 0
;
entry:
%mul = mul nsw i64 %n, 10
@@ -81,8 +76,6 @@ define i32 @gep_i8_vs_i32(ptr nocapture %A, i64 %n, i64 %m) {
; CHECK-NEXT: Equal predicate: (zext i2 (trunc i64 %n to i2) to i64) == 0
; CHECK-NEXT: Src: store i32 42, ptr %arrayidx1, align 4 --> Dst: store i32 42, ptr %arrayidx1, align 4
; CHECK-NEXT: da analyze - none!
-; CHECK-NEXT: Runtime Assumptions:
-; CHECK-NEXT: Equal predicate: (zext i2 (trunc i64 %n to i2) to i64) == 0
;
entry:
%arrayidx0 = getelementptr inbounds i8, ptr %A, i64 %n
diff --git a/llvm/test/Analysis/DependenceAnalysis/MIVCheckConst.ll b/llvm/test/Analysis/DependenceAnalysis/MIVCheckConst.ll
index f5be89a51f484..bcf73683e4dab 100644
--- a/llvm/test/Analysis/DependenceAnalysis/MIVCheckConst.ll
+++ b/llvm/test/Analysis/DependenceAnalysis/MIVCheckConst.ll
@@ -50,9 +50,6 @@ define void @test(ptr %A, ptr %B, i1 %arg, i32 %n, i32 %m) align 2 {
; CHECK-NEXT: Equal predicate: (8 * (zext i4 (trunc i32 %v1 to i4) to i32))<nuw><nsw> == 0
; CHECK-NEXT: Src: %v32 = load <32 x i32>, ptr %v30, align 128 --> Dst: %v32 = load <32 x i32>, ptr %v30, align 128
; CHECK-NEXT: da analyze - consistent input [0 S S]!
-; CHECK-NEXT: Runtime Assumptions:
-; CHECK-NEXT: Equal predicate: (zext i7 (4 * (trunc i32 %v1 to i7) * (1 + (trunc i32 %n to i7))) to i32) == 0
-; CHECK-NEXT: Equal predicate: (8 * (zext i4 (trunc i32 %v1 to i4) to i32))<nuw><nsw> == 0
;
entry:
%v1 = load i32, ptr %B, align 4
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