[llvm] 6e2e06f - [DA] Refactor the signature of the Exact RDIV test (NFCI) (#189535)

[via llvm-commits]

Author: Ruoyu Qiu
Date: 2026-03-31T08:20:06Z
New Revision: 6e2e06f98e164be53528ac19c7a307e92caa53eb

URL: https://github.com/llvm/llvm-project/commit/6e2e06f98e164be53528ac19c7a307e92caa53eb
DIFF: https://github.com/llvm/llvm-project/commit/6e2e06f98e164be53528ac19c7a307e92caa53eb.diff

LOG: [DA] Refactor the signature of the Exact RDIV test (NFCI) (#189535)

Added: 
    

Modified: 
    llvm/include/llvm/Analysis/DependenceAnalysis.h
    llvm/lib/Analysis/DependenceAnalysis.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Analysis/DependenceAnalysis.h b/llvm/include/llvm/Analysis/DependenceAnalysis.h
index 7ca7dde467085..ac819ec271b07 100644
--- a/llvm/include/llvm/Analysis/DependenceAnalysis.h
+++ b/llvm/include/llvm/Analysis/DependenceAnalysis.h
@@ -583,9 +583,7 @@ class DependenceInfo {
   /// Returns true if any possible dependence is disproved.
   /// Works in some cases that symbolicRDIVtest doesn't,
   /// and vice versa.
-  bool exactRDIVtest(const SCEV *SrcCoeff, const SCEV *DstCoeff,
-                     const SCEV *SrcConst, const SCEV *DstConst,
-                     const Loop *SrcLoop, const Loop *DstLoop,
+  bool exactRDIVtest(const SCEVAddRecExpr *Src, const SCEVAddRecExpr *Dst,
                      FullDependence &Result) const;
 
   /// gcdMIVtest - Tests an MIV subscript pair for dependence.

diff  --git a/llvm/lib/Analysis/DependenceAnalysis.cpp b/llvm/lib/Analysis/DependenceAnalysis.cpp
index c9371f39c0e18..1734983569a8f 100644
--- a/llvm/lib/Analysis/DependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/DependenceAnalysis.cpp
@@ -1937,13 +1937,16 @@ bool DependenceInfo::weakZeroDstSIVtest(const SCEVAddRecExpr *Src,
 // and a and b are constants.
 // Returns true if any possible dependence is disproved.
 // Works in some cases that symbolicRDIVtest doesn't, and vice versa.
-bool DependenceInfo::exactRDIVtest(const SCEV *SrcCoeff, const SCEV *DstCoeff,
-                                   const SCEV *SrcConst, const SCEV *DstConst,
-                                   const Loop *SrcLoop, const Loop *DstLoop,
+bool DependenceInfo::exactRDIVtest(const SCEVAddRecExpr *Src,
+                                   const SCEVAddRecExpr *Dst,
                                    FullDependence &Result) const {
   if (!isDependenceTestEnabled(DependenceTestType::ExactRDIV))
     return false;
 
+  const SCEV *SrcCoeff = Src->getStepRecurrence(*SE);
+  const SCEV *SrcConst = Src->getStart();
+  const SCEV *DstCoeff = Dst->getStepRecurrence(*SE);
+  const SCEV *DstConst = Dst->getStart();
   LLVM_DEBUG(dbgs() << "\tExact RDIV test\n");
   LLVM_DEBUG(dbgs() << "\t    SrcCoeff = " << *SrcCoeff << " = AM\n");
   LLVM_DEBUG(dbgs() << "\t    DstCoeff = " << *DstCoeff << " = BM\n");
@@ -1974,12 +1977,12 @@ bool DependenceInfo::exactRDIVtest(const SCEV *SrcCoeff, const SCEV *DstCoeff,
 
   // since SCEV construction seems to normalize, LM = 0
   std::optional<APInt> SrcUM =
-      collectNonNegativeConstantUpperBound(SrcLoop, Delta->getType());
+      collectNonNegativeConstantUpperBound(Src->getLoop(), Delta->getType());
   if (SrcUM)
     LLVM_DEBUG(dbgs() << "\t    SrcUM = " << *SrcUM << "\n");
 
   std::optional<APInt> DstUM =
-      collectNonNegativeConstantUpperBound(DstLoop, Delta->getType());
+      collectNonNegativeConstantUpperBound(Dst->getLoop(), Delta->getType());
   if (DstUM)
     LLVM_DEBUG(dbgs() << "\t    DstUM = " << *DstUM << "\n");
 
@@ -2095,25 +2098,12 @@ bool DependenceInfo::testSIV(const SCEV *Src, const SCEV *Dst, unsigned &Level,
 // Return true if dependence disproved.
 bool DependenceInfo::testRDIV(const SCEV *Src, const SCEV *Dst,
                               FullDependence &Result) const {
-  const SCEV *SrcConst, *DstConst;
-  const SCEV *SrcCoeff, *DstCoeff;
-  const Loop *SrcLoop, *DstLoop;
-
   LLVM_DEBUG(dbgs() << "    src = " << *Src << "\n");
   LLVM_DEBUG(dbgs() << "    dst = " << *Dst << "\n");
   const SCEVAddRecExpr *SrcAddRec = dyn_cast<SCEVAddRecExpr>(Src);
   const SCEVAddRecExpr *DstAddRec = dyn_cast<SCEVAddRecExpr>(Dst);
-  if (SrcAddRec && DstAddRec) {
-    SrcConst = SrcAddRec->getStart();
-    SrcCoeff = SrcAddRec->getStepRecurrence(*SE);
-    SrcLoop = SrcAddRec->getLoop();
-    DstConst = DstAddRec->getStart();
-    DstCoeff = DstAddRec->getStepRecurrence(*SE);
-    DstLoop = DstAddRec->getLoop();
-  } else
-    llvm_unreachable("RDIV expected at least one AddRec");
-  return exactRDIVtest(SrcCoeff, DstCoeff, SrcConst, DstConst, SrcLoop, DstLoop,
-                       Result) ||
+  assert(SrcAddRec && DstAddRec && "Unexpected non-addrec input");
+  return exactRDIVtest(SrcAddRec, DstAddRec, Result) ||
          gcdMIVtest(Src, Dst, Result);
 }