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[DA] Refactor signature of weakCrossingSIVtest and check inputs (NFCI) (#187117)

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Passing SCEVAddRecExpr objects directly to weakCrossingSIVtest and
checking the validity of the input operands
This commit is contained in:
Ehsan Amiri 2026-03-27 13:57:08 -04:00 committed by GitHub
parent ead9ac8331
commit 00aebbff71
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
2 changed files with 14 additions and 13 deletions
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6
llvm/include/llvm/Analysis/DependenceAnalysis.h
View File

@ -535,10 +535,8 @@ private:
/// Returns true if any possible dependence is disproved.
/// If there might be a dependence, returns false.
/// Sets appropriate direction entry.
bool weakCrossingSIVtest(const SCEV *SrcCoeff, const SCEV *SrcConst,
const SCEV *DstConst, const Loop *CurrentSrcLoop,
const Loop *CurrentDstLoop, unsigned Level,
FullDependence &Result) const;
bool weakCrossingSIVtest(const SCEVAddRecExpr *Src, const SCEVAddRecExpr *Dst,
unsigned Level, FullDependence &Result) const;
/// ExactSIVtest - Tests the SIV subscript pair
/// (Src and Dst) for dependence.

21
llvm/lib/Analysis/DependenceAnalysis.cpp
View File

@ -1363,15 +1363,20 @@ bool DependenceInfo::strongSIVtest(const SCEVAddRecExpr *Src,
// Can determine iteration for splitting.
//
// Return true if dependence disproved.
bool DependenceInfo::weakCrossingSIVtest(const SCEV *Coeff,
const SCEV *SrcConst,
const SCEV *DstConst,
const Loop *CurSrcLoop,
const Loop *CurDstLoop, unsigned Level,
bool DependenceInfo::weakCrossingSIVtest(const SCEVAddRecExpr *Src,
const SCEVAddRecExpr *Dst,
unsigned Level,
FullDependence &Result) const {
if (!isDependenceTestEnabled(DependenceTestType::WeakCrossingSIV))
return false;
const SCEV *Coeff = Src->getStepRecurrence(*SE);
const SCEV *SrcConst = Src->getStart();
const SCEV *DstConst = Dst->getStart();
assert(Coeff == SE->getNegativeSCEV(Dst->getStepRecurrence(*SE)) &&
"Unexpected input for weakCrossingSIVtest");
LLVM_DEBUG(dbgs() << "\tWeak-Crossing SIV test\n");
LLVM_DEBUG(dbgs() << "\t Coeff = " << *Coeff << "\n");
LLVM_DEBUG(dbgs() << "\t SrcConst = " << *SrcConst << "\n");
@ -1421,6 +1426,7 @@ bool DependenceInfo::weakCrossingSIVtest(const SCEV *Coeff,
// We're certain that Delta > 0 and ConstCoeff > 0.
// Check Delta/(2*ConstCoeff) against upper loop bound
const Loop *CurSrcLoop = Src->getLoop();
if (const SCEV *UpperBound =
collectUpperBound(CurSrcLoop, Delta->getType())) {
LLVM_DEBUG(dbgs() << "\t UpperBound = " << *UpperBound << "\n");
@ -2074,8 +2080,6 @@ bool DependenceInfo::testSIV(const SCEV *Src, const SCEV *Dst, unsigned &Level,
const SCEVAddRecExpr *SrcAddRec = dyn_cast<SCEVAddRecExpr>(Src);
const SCEVAddRecExpr *DstAddRec = dyn_cast<SCEVAddRecExpr>(Dst);
if (SrcAddRec && DstAddRec) {
const SCEV *SrcConst = SrcAddRec->getStart();
const SCEV *DstConst = DstAddRec->getStart();
const SCEV *SrcCoeff = SrcAddRec->getStepRecurrence(*SE);
const SCEV *DstCoeff = DstAddRec->getStepRecurrence(*SE);
const Loop *CurSrcLoop = SrcAddRec->getLoop();
@ -2089,8 +2093,7 @@ bool DependenceInfo::testSIV(const SCEV *Src, const SCEV *Dst, unsigned &Level,
disproven = strongSIVtest(SrcAddRec, DstAddRec, Level, Result,
UnderRuntimeAssumptions);
else if (SrcCoeff == SE->getNegativeSCEV(DstCoeff))
disproven = weakCrossingSIVtest(SrcCoeff, SrcConst, DstConst, CurSrcLoop,
CurDstLoop, Level, Result);
disproven = weakCrossingSIVtest(SrcAddRec, DstAddRec, Level, Result);
else
disproven = exactSIVtest(SrcAddRec, DstAddRec, Level, Result);
return disproven || gcdMIVtest(Src, Dst, Result);