[llvm-commits] [llvm] r96151 - in /llvm/trunk: include/llvm/Analysis/ScalarEvolutionExpander.h lib/Analysis/ScalarEvolutionExpander.cpp

Dan Gohman gohman at apple.com
Sat Feb 13 19:12:47 PST 2010


Author: djg
Date: Sat Feb 13 21:12:47 2010
New Revision: 96151

URL: http://llvm.org/viewvc/llvm-project?rev=96151&view=rev
Log:
In rememberInstruction, if the value being remembered is the
current insertion point, advance the current insertion point.
This avoids a use-before-def situation in a testcase extracted
from clang which is difficult to reduce to a reasonable-sized
regression test.

Modified:
    llvm/trunk/include/llvm/Analysis/ScalarEvolutionExpander.h
    llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp

Modified: llvm/trunk/include/llvm/Analysis/ScalarEvolutionExpander.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/ScalarEvolutionExpander.h?rev=96151&r1=96150&r2=96151&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Analysis/ScalarEvolutionExpander.h (original)
+++ llvm/trunk/include/llvm/Analysis/ScalarEvolutionExpander.h Sat Feb 13 21:12:47 2010
@@ -168,9 +168,7 @@
       return S->getValue();
     }
 
-    void rememberInstruction(Value *I) {
-      if (!PostIncLoop) InsertedValues.insert(I);
-    }
+    void rememberInstruction(Value *I);
 
     Value *expandAddRecExprLiterally(const SCEVAddRecExpr *);
     PHINode *getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized,

Modified: llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp?rev=96151&r1=96150&r2=96151&view=diff

==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp Sat Feb 13 21:12:47 2010
@@ -1075,6 +1075,20 @@
   return V;
 }
 
+void SCEVExpander::rememberInstruction(Value *I) {
+  if (!PostIncLoop)
+    InsertedValues.insert(I);
+
+  // If we just claimed an existing instruction and that instruction had
+  // been the insert point, adjust the insert point forward so that 
+  // subsequently inserted code will be dominated.
+  if (Builder.GetInsertPoint() == I) {
+    BasicBlock::iterator It = cast<Instruction>(I);
+    do { ++It; } while (isInsertedInstruction(It));
+    Builder.SetInsertPoint(Builder.GetInsertBlock(), It);
+  }
+}
+
 /// getOrInsertCanonicalInductionVariable - This method returns the
 /// canonical induction variable of the specified type for the specified
 /// loop (inserting one if there is none).  A canonical induction variable





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