[llvm] 2abda66 - [NFC][DA] Remove duplicate code in checkSrcSubscript and checkDstSubscript

[Danilo Carvalho Grael via llvm-commits]

Author: Danilo Carvalho Grael
Date: 2019-12-27T10:06:19-05:00
New Revision: 2abda66848e5b7f502f978f030254118ec6751d6

URL: https://github.com/llvm/llvm-project/commit/2abda66848e5b7f502f978f030254118ec6751d6
DIFF: https://github.com/llvm/llvm-project/commit/2abda66848e5b7f502f978f030254118ec6751d6.diff

LOG: [NFC][DA] Remove duplicate code in checkSrcSubscript and checkDstSubscript

Summary:
[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.

Reviewers: sebpop, jmolloy, reames

Reviewed By: sebpop

Subscribers: bmahjour, hiraditya, llvm-commits, amehsan

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71087

Patch by zhongduo.

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 4571b465ebf1..0c4002c3c3ba 100644
--- a/llvm/include/llvm/Analysis/DependenceAnalysis.h
+++ b/llvm/include/llvm/Analysis/DependenceAnalysis.h
@@ -926,6 +926,12 @@ template <typename T> class ArrayRef;
 
     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

diff  --git a/llvm/lib/Analysis/DependenceAnalysis.cpp b/llvm/lib/Analysis/DependenceAnalysis.cpp
index c343867e09f6..9b38053c196b 100644
--- a/llvm/lib/Analysis/DependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/DependenceAnalysis.cpp
@@ -882,14 +882,13 @@ void DependenceInfo::removeMatchingExtensions(Subscript *Pair) {
   }
 }
 
-
 // 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 @@ bool DependenceInfo::checkSrcSubscript(const SCEV *Src, const Loop *LoopNest,
   }
   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);
 }