[PATCH] D71087: [DA] Remove duplicate code in checkSrcSubscript and checkDstSubscript

[Zhongduo Lin (Jimmy) via Phabricator via llvm-commits]

zhongduo created this revision.
zhongduo added reviewers: sebpop, jmolloy.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.

[DA] Move common code in checkSrcSubscript and checkDstSubscript to a
new function checkSubscript. This avoids duplicate code and possible
out of sync in the future.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D71087

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


Index: llvm/lib/Analysis/DependenceAnalysis.cpp
===================================================================
--- llvm/lib/Analysis/DependenceAnalysis.cpp
+++ llvm/lib/Analysis/DependenceAnalysis.cpp
@@ -882,14 +882,13 @@
   }
 }
 
-
 // Examine the scev and return true iff it's linear.
 // Collect any loops mentioned in the set of "Loops".
-bool DependenceInfo::checkSrcSubscript(const SCEV *Src, const Loop *LoopNest,
-                                       SmallBitVector &Loops) {
-  const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(Src);
+bool DependenceInfo::checkSubscript(const SCEV *Expr, const Loop *LoopNest,
+                                    SmallBitVector &Loops, bool IsSrc) {
+  const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(Expr);
   if (!AddRec)
-    return isLoopInvariant(Src, LoopNest);
+    return isLoopInvariant(Expr, LoopNest);
   const SCEV *Start = AddRec->getStart();
   const SCEV *Step = AddRec->getStepRecurrence(*SE);
   const SCEV *UB = SE->getBackedgeTakenCount(AddRec->getLoop());
@@ -902,33 +901,25 @@
   }
   if (!isLoopInvariant(Step, LoopNest))
     return false;
-  Loops.set(mapSrcLoop(AddRec->getLoop()));
-  return checkSrcSubscript(Start, LoopNest, Loops);
+  if (IsSrc)
+    Loops.set(mapSrcLoop(AddRec->getLoop()));
+  else
+    Loops.set(mapDstLoop(AddRec->getLoop()));
+  return checkSubscript(Start, LoopNest, Loops, IsSrc);
 }
 
-
+// Examine the scev and return true iff it's linear.
+// Collect any loops mentioned in the set of "Loops".
+bool DependenceInfo::checkSrcSubscript(const SCEV *Src, const Loop *LoopNest,
+                                       SmallBitVector &Loops) {
+  return checkSubscript(Src, LoopNest, Loops, true);
+}
 
 // Examine the scev and return true iff it's linear.
 // Collect any loops mentioned in the set of "Loops".
 bool DependenceInfo::checkDstSubscript(const SCEV *Dst, const Loop *LoopNest,
                                        SmallBitVector &Loops) {
-  const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(Dst);
-  if (!AddRec)
-    return isLoopInvariant(Dst, LoopNest);
-  const SCEV *Start = AddRec->getStart();
-  const SCEV *Step = AddRec->getStepRecurrence(*SE);
-  const SCEV *UB = SE->getBackedgeTakenCount(AddRec->getLoop());
-  if (!isa<SCEVCouldNotCompute>(UB)) {
-    if (SE->getTypeSizeInBits(Start->getType()) <
-        SE->getTypeSizeInBits(UB->getType())) {
-      if (!AddRec->getNoWrapFlags())
-        return false;
-    }
-  }
-  if (!isLoopInvariant(Step, LoopNest))
-    return false;
-  Loops.set(mapDstLoop(AddRec->getLoop()));
-  return checkDstSubscript(Start, LoopNest, Loops);
+  return checkSubscript(Dst, LoopNest, Loops, false);
 }
 
 
Index: llvm/include/llvm/Analysis/DependenceAnalysis.h
===================================================================
--- llvm/include/llvm/Analysis/DependenceAnalysis.h
+++ llvm/include/llvm/Analysis/DependenceAnalysis.h
@@ -926,6 +926,12 @@
 
     bool tryDelinearize(Instruction *Src, Instruction *Dst,
                         SmallVectorImpl<Subscript> &Pair);
+
+  private:
+    /// checkSubscript - Helper function for checkSrcSubscript and
+    /// checkDstSubscript to avoid duplicate code
+    bool checkSubscript(const SCEV *Expr, const Loop *LoopNest,
+                        SmallBitVector &Loops, bool IsSrc);
   }; // class DependenceInfo
 
   /// AnalysisPass to compute dependence information in a function


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D71087.232433.patch
Type: text/x-patch
Size: 3424 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20191205/423faeb8/attachment.bin>