https://github.com/kasuga-fj created https://github.com/llvm/llvm-project/pull/169928
None >From e764580a15d8dbc47787aaf358b4b344f4a51a75 Mon Sep 17 00:00:00 2001 From: Ryotaro Kasuga <[email protected]> Date: Fri, 28 Nov 2025 15:14:30 +0000 Subject: [PATCH] [DA] Add overflow check when calculating Delta in GCD MIV --- llvm/lib/Analysis/DependenceAnalysis.cpp | 4 +++- llvm/test/Analysis/DependenceAnalysis/gcd-miv-overflow.ll | 2 +- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/llvm/lib/Analysis/DependenceAnalysis.cpp b/llvm/lib/Analysis/DependenceAnalysis.cpp index 77b09fb15316e..73a7b59c81f27 100644 --- a/llvm/lib/Analysis/DependenceAnalysis.cpp +++ b/llvm/lib/Analysis/DependenceAnalysis.cpp @@ -2587,7 +2587,9 @@ bool DependenceInfo::gcdMIVtest(const SCEV *Src, const SCEV *Dst, const SCEV *DstConst = Coefficients; APInt ExtraGCD = APInt::getZero(BitWidth); - const SCEV *Delta = SE->getMinusSCEV(DstConst, SrcConst); + const SCEV *Delta = minusSCEVNoSignedOverflow(DstConst, SrcConst, *SE); + if (!Delta) + return false; LLVM_DEBUG(dbgs() << " Delta = " << *Delta << "\n"); const SCEVConstant *Constant = dyn_cast<SCEVConstant>(Delta); if (const SCEVAddExpr *Sum = dyn_cast<SCEVAddExpr>(Delta)) { diff --git a/llvm/test/Analysis/DependenceAnalysis/gcd-miv-overflow.ll b/llvm/test/Analysis/DependenceAnalysis/gcd-miv-overflow.ll index 618d14c75faad..76bab98207c79 100644 --- a/llvm/test/Analysis/DependenceAnalysis/gcd-miv-overflow.ll +++ b/llvm/test/Analysis/DependenceAnalysis/gcd-miv-overflow.ll @@ -89,7 +89,7 @@ define void @gcdmiv_delta_ovfl(ptr %A) { ; CHECK-GCD-MIV-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 0, ptr %idx.0, align 1 ; CHECK-GCD-MIV-NEXT: da analyze - consistent output [*]! ; CHECK-GCD-MIV-NEXT: Src: store i8 0, ptr %idx.0, align 1 --> Dst: store i8 1, ptr %idx.1, align 1 -; CHECK-GCD-MIV-NEXT: da analyze - none! +; CHECK-GCD-MIV-NEXT: da analyze - consistent output [*|<]! ; CHECK-GCD-MIV-NEXT: Src: store i8 1, ptr %idx.1, align 1 --> Dst: store i8 1, ptr %idx.1, align 1 ; CHECK-GCD-MIV-NEXT: da analyze - consistent output [*]! ; _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
