[llvm] [DA] Add test where ExactSIV misses dependency due to overflow (NFC) (PR #157085)

Ryotaro Kasuga via llvm-commits llvm-commits at lists.llvm.org
Tue Sep 16 11:48:33 PDT 2025


https://github.com/kasuga-fj updated https://github.com/llvm/llvm-project/pull/157085

>From fb2bcf209ed2b66cf46d333f11b0ac2f00710b3f Mon Sep 17 00:00:00 2001
From: Ryotaro Kasuga <kasuga.ryotaro at fujitsu.com>
Date: Fri, 5 Sep 2025 10:13:22 +0000
Subject: [PATCH 1/3] [DA] Add option to run only SIV routines

---
 llvm/lib/Analysis/DependenceAnalysis.cpp      |  14 ++
 .../Analysis/DependenceAnalysis/ExactSIV.ll   | 198 ++++++++++++++++++
 2 files changed, 212 insertions(+)

diff --git a/llvm/lib/Analysis/DependenceAnalysis.cpp b/llvm/lib/Analysis/DependenceAnalysis.cpp
index 43eefc3120f9e..0f77a1410e83b 100644
--- a/llvm/lib/Analysis/DependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/DependenceAnalysis.cpp
@@ -121,6 +121,12 @@ static cl::opt<unsigned> MIVMaxLevelThreshold(
     cl::desc("Maximum depth allowed for the recursive algorithm used to "
              "explore MIV direction vectors."));
 
+static cl::opt<bool> RunSIVRoutinesOnly(
+    "da-run-siv-routines-only", cl::init(false), cl::ReallyHidden,
+    cl::desc("Run only SIV routines and disable others (ZIV, RDIV, and MIV). "
+             "The purpose is mainly to exclude the influence of those routines "
+             "in regression tests for SIV routines."));
+
 //===----------------------------------------------------------------------===//
 // basics
 
@@ -1980,6 +1986,8 @@ bool DependenceInfo::exactRDIVtest(const SCEV *SrcCoeff, const SCEV *DstCoeff,
                                    const SCEV *SrcConst, const SCEV *DstConst,
                                    const Loop *SrcLoop, const Loop *DstLoop,
                                    FullDependence &Result) const {
+  if (RunSIVRoutinesOnly)
+    return false;
   LLVM_DEBUG(dbgs() << "\tExact RDIV test\n");
   LLVM_DEBUG(dbgs() << "\t    SrcCoeff = " << *SrcCoeff << " = AM\n");
   LLVM_DEBUG(dbgs() << "\t    DstCoeff = " << *DstCoeff << " = BM\n");
@@ -2124,6 +2132,8 @@ bool DependenceInfo::symbolicRDIVtest(const SCEV *A1, const SCEV *A2,
                                       const SCEV *C1, const SCEV *C2,
                                       const Loop *Loop1,
                                       const Loop *Loop2) const {
+  if (RunSIVRoutinesOnly)
+    return false;
   ++SymbolicRDIVapplications;
   LLVM_DEBUG(dbgs() << "\ttry symbolic RDIV test\n");
   LLVM_DEBUG(dbgs() << "\t    A1 = " << *A1);
@@ -2433,6 +2443,8 @@ bool DependenceInfo::accumulateCoefficientsGCD(const SCEV *Expr,
 // to "a common divisor".
 bool DependenceInfo::gcdMIVtest(const SCEV *Src, const SCEV *Dst,
                                 FullDependence &Result) const {
+  if (RunSIVRoutinesOnly)
+    return false;
   LLVM_DEBUG(dbgs() << "starting gcd\n");
   ++GCDapplications;
   unsigned BitWidth = SE->getTypeSizeInBits(Src->getType());
@@ -2599,6 +2611,8 @@ bool DependenceInfo::gcdMIVtest(const SCEV *Src, const SCEV *Dst,
 bool DependenceInfo::banerjeeMIVtest(const SCEV *Src, const SCEV *Dst,
                                      const SmallBitVector &Loops,
                                      FullDependence &Result) const {
+  if (RunSIVRoutinesOnly)
+    return false;
   LLVM_DEBUG(dbgs() << "starting Banerjee\n");
   ++BanerjeeApplications;
   LLVM_DEBUG(dbgs() << "    Src = " << *Src << '\n');
diff --git a/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll b/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll
index b6b44ad4bfc53..0fe62991fede9 100644
--- a/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll
+++ b/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll
@@ -1,6 +1,8 @@
 ; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 5
 ; RUN: opt < %s -disable-output "-passes=print<da>" -aa-pipeline=basic-aa 2>&1 \
 ; RUN: | FileCheck %s
+; RUN: opt < %s -disable-output "-passes=print<da>" -da-run-siv-routines-only 2>&1 \
+; RUN: | FileCheck %s --check-prefix=CHECK-SIV-ONLY
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.6.0"
@@ -25,6 +27,20 @@ define void @exact0(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact0'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - flow [<=|<]!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -69,6 +85,20 @@ define void @exact1(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact1'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx3, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx3, align 4 --> Dst: %0 = load i32, ptr %arrayidx3, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx3, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -114,6 +144,20 @@ define void @exact2(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact2'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx1, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx1, align 4 --> Dst: %0 = load i32, ptr %arrayidx1, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx1, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -157,6 +201,20 @@ define void @exact3(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact3'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx1, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - flow [>]!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx1, align 4 --> Dst: %0 = load i32, ptr %arrayidx1, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx1, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -200,6 +258,20 @@ define void @exact4(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact4'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx1, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - flow [>]!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx1, align 4 --> Dst: %0 = load i32, ptr %arrayidx1, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx1, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -243,6 +315,20 @@ define void @exact5(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact5'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx1, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - flow [=>|<]!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx1, align 4 --> Dst: %0 = load i32, ptr %arrayidx1, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx1, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -286,6 +372,20 @@ define void @exact6(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact6'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx1, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - flow [=>|<]!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx1, align 4 --> Dst: %0 = load i32, ptr %arrayidx1, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx1, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -329,6 +429,20 @@ define void @exact7(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact7'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx1, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - flow [*|<]!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx1, align 4 --> Dst: %0 = load i32, ptr %arrayidx1, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx1, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -372,6 +486,20 @@ define void @exact8(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact8'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -415,6 +543,20 @@ define void @exact9(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact9'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - flow [>]!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -458,6 +600,20 @@ define void @exact10(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact10'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - flow [>]!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -501,6 +657,20 @@ define void @exact11(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact11'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - flow [=>|<]!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -544,6 +714,20 @@ define void @exact12(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact12'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - flow [=>|<]!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 
@@ -587,6 +771,20 @@ define void @exact13(ptr %A, ptr %B) nounwind uwtable ssp {
 ; CHECK-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
 ; CHECK-NEXT:    da analyze - none!
 ;
+; CHECK-SIV-ONLY-LABEL: 'exact13'
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %conv, ptr %arrayidx, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - flow [*|<]!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %conv, ptr %arrayidx, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: %0 = load i32, ptr %arrayidx2, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: %0 = load i32, ptr %arrayidx2, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - confused!
+; CHECK-SIV-ONLY-NEXT:  Src: store i32 %0, ptr %B.addr.01, align 4 --> Dst: store i32 %0, ptr %B.addr.01, align 4
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
 entry:
   br label %for.body
 

>From 4e43533b48aa613b05fb0753ac290809da8f28d1 Mon Sep 17 00:00:00 2001
From: Ryotaro Kasuga <kasuga.ryotaro at fujitsu.com>
Date: Fri, 5 Sep 2025 11:32:54 +0000
Subject: [PATCH 2/3] [DA] Add test where ExactSIV misses dependency due to
 overflow (NFC)

---
 .../Analysis/DependenceAnalysis/ExactSIV.ll   | 120 ++++++++++++++++++
 1 file changed, 120 insertions(+)

diff --git a/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll b/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll
index 0fe62991fede9..a16751397c487 100644
--- a/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll
+++ b/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll
@@ -807,3 +807,123 @@ for.body:                                         ; preds = %entry, %for.body
 for.end:                                          ; preds = %for.body
   ret void
 }
+
+;; max_i = INT64_MAX/6  // 1537228672809129301
+;; for (long long i = 0; i <= max_i; i++) {
+;;   A[-6*i + INT64_MAX] = 0;
+;;   if (i)
+;;     A[3*i - 2] = 1;
+;; }
+;;
+;; FIXME: There is a loop-carried dependency between
+;; `A[-6*i + INT64_MAX]` and `A[3*i - 2]`. For example,
+;;
+;; | memory location        | -6*i + INT64_MAX       | 3*i - 2
+;; |------------------------|------------------------|-----------
+;; | A[1]                   | i = max_i              | i = 1
+;; | A[4611686018427387901] | i = 768614336404564651 | i = max_i
+;;
+;; Actually,
+;;  * 1                   = -6*max_i              + INT64_MAX = 3*1     - 2
+;;  * 4611686018427387901 = -6*768614336404564651 + INT64_MAX = 3*max_i - 2
+;;
+
+define void @exact14(ptr %A) {
+; CHECK-LABEL: 'exact14'
+; CHECK-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1
+; CHECK-NEXT:    da analyze - none!
+; CHECK-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
+; CHECK-NEXT:    da analyze - none!
+; CHECK-NEXT:  Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
+; CHECK-NEXT:    da analyze - none!
+;
+; CHECK-SIV-ONLY-LABEL: 'exact14'
+; CHECK-SIV-ONLY-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
+entry:
+  br label %loop.header
+
+loop.header:
+  %i = phi i64 [ 0, %entry ], [ %i.inc, %loop.latch ]
+  %subscript.0 = phi i64 [ 9223372036854775807, %entry ], [ %subscript.0.next, %loop.latch ]
+  %subscript.1 = phi i64 [ -2, %entry ], [ %subscript.1.next, %loop.latch ]
+  %idx.0 = getelementptr inbounds i8, ptr %A, i64 %subscript.0
+  store i8 0, ptr %idx.0
+  %cond.store = icmp ne i64 %i, 0
+  br i1 %cond.store, label %if.store, label %loop.latch
+
+if.store:
+  %idx.1 = getelementptr inbounds i8, ptr %A, i64 %subscript.1
+  store i8 1, ptr %idx.1
+  br label %loop.latch
+
+loop.latch:
+  %i.inc = add nuw nsw i64 %i, 1
+  %subscript.0.next = add nsw i64 %subscript.0, -6
+  %subscript.1.next = add nsw i64 %subscript.1, 3
+  %exitcond = icmp sgt i64 %i.inc, 1537228672809129301
+  br i1 %exitcond, label %exit, label %loop.header
+
+exit:
+  ret void
+}
+
+;; A generalized version of @exact14.
+;;
+;; for (long long i = 0; i <= n / 6; i++) {
+;;   A[-6*i + n] = 0;
+;;   if (i)
+;;     A[3*i - 2] = 1;
+;; }
+
+define void @exact15(ptr %A, i64 %n) {
+; CHECK-LABEL: 'exact15'
+; CHECK-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1
+; CHECK-NEXT:    da analyze - none!
+; CHECK-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
+; CHECK-NEXT:    da analyze - output [*|<]!
+; CHECK-NEXT:  Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
+; CHECK-NEXT:    da analyze - none!
+;
+; CHECK-SIV-ONLY-LABEL: 'exact15'
+; CHECK-SIV-ONLY-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+; CHECK-SIV-ONLY-NEXT:  Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
+; CHECK-SIV-ONLY-NEXT:    da analyze - output [*|<]!
+; CHECK-SIV-ONLY-NEXT:  Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1
+; CHECK-SIV-ONLY-NEXT:    da analyze - none!
+;
+entry:
+  %bound = sdiv i64 %n, 6
+  %guard = icmp sgt i64 %n, 0
+  br i1 %guard, label %loop.header, label %exit
+
+loop.header:
+  %i = phi i64 [ 0, %entry ], [ %i.inc, %loop.latch ]
+  %subscript.0 = phi i64 [ %n, %entry ], [ %subscript.0.next, %loop.latch ]
+  %subscript.1 = phi i64 [ -2, %entry ], [ %subscript.1.next, %loop.latch ]
+  %idx.0 = getelementptr inbounds i8, ptr %A, i64 %subscript.0
+  store i8 0, ptr %idx.0
+  %cond.store = icmp ne i64 %i, 0
+  br i1 %cond.store, label %if.store, label %loop.latch
+
+if.store:
+  %idx.1 = getelementptr inbounds i8, ptr %A, i64 %subscript.1
+  store i8 1, ptr %idx.1
+  br label %loop.latch
+
+loop.latch:
+  %i.inc = add nuw nsw i64 %i, 1
+  %subscript.0.next = add nsw i64 %subscript.0, -6
+  %subscript.1.next = add nsw i64 %subscript.1, 3
+  %exitcond = icmp sgt i64 %i.inc, %bound
+  br i1 %exitcond, label %exit, label %loop.header
+
+exit:
+  ret void
+}

>From 6a3a5fcb1b0d9d99a5de3c47cef9a26e18542919 Mon Sep 17 00:00:00 2001
From: Ryotaro Kasuga <kasuga.ryotaro at fujitsu.com>
Date: Tue, 16 Sep 2025 13:08:24 +0000
Subject: [PATCH 3/3] address review comment

---
 llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll b/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll
index a16751397c487..2a809c32d7d21 100644
--- a/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll
+++ b/llvm/test/Analysis/DependenceAnalysis/ExactSIV.ll
@@ -815,8 +815,8 @@ for.end:                                          ; preds = %for.body
 ;;     A[3*i - 2] = 1;
 ;; }
 ;;
-;; FIXME: There is a loop-carried dependency between
-;; `A[-6*i + INT64_MAX]` and `A[3*i - 2]`. For example,
+;; FIXME: DependencyAnalsysis currently detects no dependency between
+;; `A[-6*i + INT64_MAX]` and `A[3*i - 2]`, but it does exist. For example,
 ;;
 ;; | memory location        | -6*i + INT64_MAX       | 3*i - 2
 ;; |------------------------|------------------------|-----------



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