[llvm-commits] [llvm] r114105 - /llvm/trunk/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp

[Owen Anderson]

Author: resistor
Date: Thu Sep 16 13:35:07 2010
New Revision: 114105

URL: http://llvm.org/viewvc/llvm-project?rev=114105&view=rev
Log:
Use a depth-first iteratation in CorrelatedValuePropagation to avoid wasting time trying
to optimize unreachable blocks.

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

Modified: llvm/trunk/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp?rev=114105&r1=114104&r2=114105&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp Thu Sep 16 13:35:07 2010
@@ -19,6 +19,7 @@
 #include "llvm/Analysis/LazyValueInfo.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Transforms/Utils/Local.h"
+#include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/Statistic.h"
 using namespace llvm;
 
@@ -166,7 +167,10 @@
   
   bool FnChanged = false;
   
-  for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) {
+  // Perform a depth-first walk of the CFG so that we don't waste time
+  // optimizing unreachable blocks.
+  for (df_iterator<BasicBlock*> FI = df_begin(&F.getEntryBlock()),
+       FE = df_end(&F.getEntryBlock()); FI != FE; ++FI) {
     bool BBChanged = false;
     for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); BI != BE; ) {
       Instruction *II = BI++;
@@ -191,7 +195,7 @@
     // Propagating correlated values might leave cruft around.
     // Try to clean it up before we continue.
     if (BBChanged)
-      SimplifyInstructionsInBlock(FI);
+      SimplifyInstructionsInBlock(*FI);
     
     FnChanged |= BBChanged;
   }