[llvm-commits] [llvm] r53762 - /llvm/trunk/lib/Transforms/Scalar/GVN.cpp

[Owen Anderson]

Author: resistor
Date: Fri Jul 18 13:03:38 2008
New Revision: 53762

URL: http://llvm.org/viewvc/llvm-project?rev=53762&view=rev
Log:
Make PRE actually handle critical edges (by splitting them).  Confirmed that bootstrap passes with this change.

Modified:
    llvm/trunk/lib/Transforms/Scalar/GVN.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/GVN.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/GVN.cpp?rev=53762&r1=53761&r2=53762&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/GVN.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/GVN.cpp Fri Jul 18 13:03:38 2008
@@ -1136,8 +1136,11 @@
     changed |= shouldContinue;
   }
   
-  if (EnablePRE)
-    changed |= performPRE(F);
+  if (EnablePRE) {
+    bool PREChanged = false;
+    while (PREChanged = performPRE(F))
+      changed |= PREChanged;
+  }
   
   return changed;
 }
@@ -1336,7 +1339,7 @@
        I = toSplit.begin(), E = toSplit.end(); I != E; ++I)
     SplitCriticalEdge(I->first, I->second, this);
   
-  return changed;
+  return changed || toSplit.size();
 }
 
 // iterateOnFunction - Executes one iteration of GVN