[llvm] r245408 - Fix how DependenceAnalysis calls delinearization
Hal Finkel via llvm-commits
llvm-commits at lists.llvm.org
Tue Aug 18 19:56:36 PDT 2015
Author: hfinkel
Date: Tue Aug 18 21:56:36 2015
New Revision: 245408
URL: http://llvm.org/viewvc/llvm-project?rev=245408&view=rev
Log:
Fix how DependenceAnalysis calls delinearization
Fix how DependenceAnalysis calls delinearization, mirroring what is done in
Delinearization.cpp (mostly by making sure to call getSCEVAtScope before
delinearizing, and by removing the unnecessary 'Pairs == 1' check).
Patch by Vaivaswatha Nagaraj!
Modified:
llvm/trunk/include/llvm/Analysis/DependenceAnalysis.h
llvm/trunk/lib/Analysis/DependenceAnalysis.cpp
llvm/trunk/test/Analysis/DependenceAnalysis/GCD.ll
Modified: llvm/trunk/include/llvm/Analysis/DependenceAnalysis.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/DependenceAnalysis.h?rev=245408&r1=245407&r2=245408&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/DependenceAnalysis.h (original)
+++ llvm/trunk/include/llvm/Analysis/DependenceAnalysis.h Tue Aug 18 21:56:36 2015
@@ -926,9 +926,8 @@ namespace llvm {
void updateDirection(Dependence::DVEntry &Level,
const Constraint &CurConstraint) const;
- bool tryDelinearize(const SCEV *SrcSCEV, const SCEV *DstSCEV,
- SmallVectorImpl<Subscript> &Pair,
- const SCEV *ElementSize);
+ bool tryDelinearize(Instruction *Src, Instruction *Dst,
+ SmallVectorImpl<Subscript> &Pair);
public:
static char ID; // Class identification, replacement for typeinfo
Modified: llvm/trunk/lib/Analysis/DependenceAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/DependenceAnalysis.cpp?rev=245408&r1=245407&r2=245408&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/DependenceAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/DependenceAnalysis.cpp Tue Aug 18 21:56:36 2015
@@ -3245,20 +3245,36 @@ void DependenceAnalysis::updateDirection
/// source and destination array references are recurrences on a nested loop,
/// this function flattens the nested recurrences into separate recurrences
/// for each loop level.
-bool DependenceAnalysis::tryDelinearize(const SCEV *SrcSCEV,
- const SCEV *DstSCEV,
- SmallVectorImpl<Subscript> &Pair,
- const SCEV *ElementSize) {
+bool DependenceAnalysis::tryDelinearize(Instruction *Src,
+ Instruction *Dst,
+ SmallVectorImpl<Subscript> &Pair)
+{
+ Value *SrcPtr = getPointerOperand(Src);
+ Value *DstPtr = getPointerOperand(Dst);
+
+ Loop *SrcLoop = LI->getLoopFor(Src->getParent());
+ Loop *DstLoop = LI->getLoopFor(Dst->getParent());
+
+ // Below code mimics the code in Delinearization.cpp
+ const SCEV *SrcAccessFn =
+ SE->getSCEVAtScope(SrcPtr, SrcLoop);
+ const SCEV *DstAccessFn =
+ SE->getSCEVAtScope(DstPtr, DstLoop);
+
const SCEVUnknown *SrcBase =
- dyn_cast<SCEVUnknown>(SE->getPointerBase(SrcSCEV));
+ dyn_cast<SCEVUnknown>(SE->getPointerBase(SrcAccessFn));
const SCEVUnknown *DstBase =
- dyn_cast<SCEVUnknown>(SE->getPointerBase(DstSCEV));
+ dyn_cast<SCEVUnknown>(SE->getPointerBase(DstAccessFn));
if (!SrcBase || !DstBase || SrcBase != DstBase)
return false;
- SrcSCEV = SE->getMinusSCEV(SrcSCEV, SrcBase);
- DstSCEV = SE->getMinusSCEV(DstSCEV, DstBase);
+ const SCEV *ElementSize = SE->getElementSize(Src);
+ if (ElementSize != SE->getElementSize(Dst))
+ return false;
+
+ const SCEV *SrcSCEV = SE->getMinusSCEV(SrcAccessFn, SrcBase);
+ const SCEV *DstSCEV = SE->getMinusSCEV(DstAccessFn, DstBase);
const SCEVAddRecExpr *SrcAR = dyn_cast<SCEVAddRecExpr>(SrcSCEV);
const SCEVAddRecExpr *DstAR = dyn_cast<SCEVAddRecExpr>(DstSCEV);
@@ -3331,7 +3347,6 @@ static void dumpSmallBitVector(SmallBitV
}
#endif
-
// depends -
// Returns NULL if there is no dependence.
// Otherwise, return a Dependence with as many details as possible.
@@ -3426,10 +3441,11 @@ DependenceAnalysis::depends(Instruction
Pair[0].Dst = DstSCEV;
}
- if (Delinearize && Pairs == 1 && CommonLevels > 1 &&
- tryDelinearize(Pair[0].Src, Pair[0].Dst, Pair, SE->getElementSize(Src))) {
- DEBUG(dbgs() << " delinerized GEP\n");
- Pairs = Pair.size();
+ if (Delinearize && CommonLevels > 1) {
+ if (tryDelinearize(Src, Dst, Pair)) {
+ DEBUG(dbgs() << " delinerized GEP\n");
+ Pairs = Pair.size();
+ }
}
for (unsigned P = 0; P < Pairs; ++P) {
@@ -3851,10 +3867,11 @@ const SCEV *DependenceAnalysis::getSpli
Pair[0].Dst = DstSCEV;
}
- if (Delinearize && Pairs == 1 && CommonLevels > 1 &&
- tryDelinearize(Pair[0].Src, Pair[0].Dst, Pair, SE->getElementSize(Src))) {
- DEBUG(dbgs() << " delinerized GEP\n");
- Pairs = Pair.size();
+ if (Delinearize && CommonLevels > 1) {
+ if (tryDelinearize(Src, Dst, Pair)) {
+ DEBUG(dbgs() << " delinerized GEP\n");
+ Pairs = Pair.size();
+ }
}
for (unsigned P = 0; P < Pairs; ++P) {
Modified: llvm/trunk/test/Analysis/DependenceAnalysis/GCD.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/DependenceAnalysis/GCD.ll?rev=245408&r1=245407&r2=245408&view=diff
==============================================================================
--- llvm/trunk/test/Analysis/DependenceAnalysis/GCD.ll (original)
+++ llvm/trunk/test/Analysis/DependenceAnalysis/GCD.ll Tue Aug 18 21:56:36 2015
@@ -269,10 +269,10 @@ entry:
; CHECK: da analyze - none!
; DELIN: 'Dependence Analysis' for function 'gcd4'
-; DELIN: da analyze - output [* *]!
+; DELIN: da analyze - none!
; DELIN: da analyze - none!
; DELIN: da analyze - confused!
-; DELIN: da analyze - input [* *]!
+; DELIN: da analyze - none!
; DELIN: da analyze - confused!
; DELIN: da analyze - none!
@@ -339,10 +339,10 @@ entry:
; CHECK: da analyze - none!
; DELIN: 'Dependence Analysis' for function 'gcd5'
-; DELIN: da analyze - output [* *]!
-; DELIN: da analyze - flow [<> *]!
+; DELIN: da analyze - none!
+; DELIN: da analyze - flow [> *]!
; DELIN: da analyze - confused!
-; DELIN: da analyze - input [* *]!
+; DELIN: da analyze - none!
; DELIN: da analyze - confused!
; DELIN: da analyze - none!
@@ -410,10 +410,10 @@ entry:
; CHECK: da analyze - output [* *]!
; DELIN: 'Dependence Analysis' for function 'gcd6'
-; DELIN: da analyze - output [* *]!
+; DELIN: da analyze - none!
; DELIN: da analyze - none!
; DELIN: da analyze - confused!
-; DELIN: da analyze - input [* *]!
+; DELIN: da analyze - none!
; DELIN: da analyze - confused!
; DELIN: da analyze - output [* *]!
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