[llvm] dc09c65 - LoopIdiomRecognize: use ExpandedValuesCleaner in another place

[Jon Roelofs via llvm-commits]

Author: Jon Roelofs
Date: 2020-07-21T09:32:23-06:00
New Revision: dc09c65f638f177265f47d897469888cfa011041

URL: https://github.com/llvm/llvm-project/commit/dc09c65f638f177265f47d897469888cfa011041
DIFF: https://github.com/llvm/llvm-project/commit/dc09c65f638f177265f47d897469888cfa011041.diff

LOG: LoopIdiomRecognize: use ExpandedValuesCleaner in another place

This is a necessary cleanup after having expanded a SCEV.

See: https://reviews.llvm.org/D84071#inline-774728

Differential Revision: https://reviews.llvm.org/D84174

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
index d6043099000b..fc980cf3689f 100644
--- a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
@@ -295,6 +295,31 @@ static void deleteDeadInstruction(Instruction *I) {
   I->eraseFromParent();
 }
 
+namespace {
+class ExpandedValuesCleaner {
+  SCEVExpander &Expander;
+  TargetLibraryInfo *TLI;
+  SmallVector<Value *, 4> ExpandedValues;
+  bool Commit = false;
+
+public:
+  ExpandedValuesCleaner(SCEVExpander &Expander, TargetLibraryInfo *TLI)
+      : Expander(Expander), TLI(TLI) {}
+
+  void add(Value *V) { ExpandedValues.push_back(V); }
+
+  void commit() { Commit = true; }
+
+  ~ExpandedValuesCleaner() {
+    if (!Commit) {
+      Expander.clear();
+      for (auto *V : ExpandedValues)
+        RecursivelyDeleteTriviallyDeadInstructions(V, TLI);
+    }
+  }
+};
+} // namespace
+
 //===----------------------------------------------------------------------===//
 //
 //          Implementation of LoopIdiomRecognize
@@ -908,6 +933,7 @@ bool LoopIdiomRecognize::processLoopStridedStore(
   BasicBlock *Preheader = CurLoop->getLoopPreheader();
   IRBuilder<> Builder(Preheader->getTerminator());
   SCEVExpander Expander(*SE, *DL, "loop-idiom");
+  ExpandedValuesCleaner EVC(Expander, TLI);
 
   Type *DestInt8PtrTy = Builder.getInt8PtrTy(DestAS);
   Type *IntIdxTy = DL->getIndexType(DestPtr->getType());
@@ -930,6 +956,7 @@ bool LoopIdiomRecognize::processLoopStridedStore(
   // base pointer and checking the region.
   Value *BasePtr =
       Expander.expandCodeFor(Start, DestInt8PtrTy, Preheader->getTerminator());
+  EVC.add(BasePtr);
 
   // From here on out, conservatively report to the pass manager that we've
   // changed the IR, even if we later clean up these added instructions. There
@@ -941,12 +968,8 @@ bool LoopIdiomRecognize::processLoopStridedStore(
   Changed = true;
 
   if (mayLoopAccessLocation(BasePtr, ModRefInfo::ModRef, CurLoop, BECount,
-                            StoreSize, *AA, Stores)) {
-    Expander.clear();
-    // If we generated new code for the base pointer, clean up.
-    RecursivelyDeleteTriviallyDeadInstructions(BasePtr, TLI);
+                            StoreSize, *AA, Stores))
     return Changed;
-  }
 
   if (avoidLIRForMultiBlockLoop(/*IsMemset=*/true, IsLoopMemset))
     return Changed;
@@ -1018,34 +1041,10 @@ bool LoopIdiomRecognize::processLoopStridedStore(
   if (MSSAU && VerifyMemorySSA)
     MSSAU->getMemorySSA()->verifyMemorySSA();
   ++NumMemSet;
+  EVC.commit();
   return true;
 }
 
-namespace {
-class ExpandedValuesCleaner {
-  SCEVExpander &Expander;
-  TargetLibraryInfo *TLI;
-  SmallVector<Value *, 4> ExpandedValues;
-  bool Commit = false;
-
-public:
-  ExpandedValuesCleaner(SCEVExpander &Expander, TargetLibraryInfo *TLI)
-      : Expander(Expander), TLI(TLI) {}
-
-  void add(Value *V) { ExpandedValues.push_back(V); }
-
-  void commit() { Commit = true; }
-
-  ~ExpandedValuesCleaner() {
-    if (!Commit) {
-      Expander.clear();
-      for (auto *V : ExpandedValues)
-        RecursivelyDeleteTriviallyDeadInstructions(V, TLI);
-    }
-  }
-};
-} // namespace
-
 /// If the stored value is a strided load in the same loop with the same stride
 /// this may be transformable into a memcpy.  This kicks in for stuff like
 /// for (i) A[i] = B[i];