[llvm-commits] [llvm] r151127 - /llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp

[Rafael Espindola]

Author: rafael
Date: Tue Feb 21 21:44:46 2012
New Revision: 151127

URL: http://llvm.org/viewvc/llvm-project?rev=151127&view=rev
Log:
Improve comment. Thanks for Andrew for the suggestion.

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

Modified: llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp?rev=151127&r1=151126&r2=151127&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp Tue Feb 21 21:44:46 2012
@@ -53,8 +53,9 @@
     if (U->getType() == Ty)
       if (CastInst *CI = dyn_cast<CastInst>(U))
         if (CI->getOpcode() == Op) {
-          // If the cast isn't where we want it or if it doesn't dominate
-          // a use in BIP, fix it.
+          // If the cast isn't where we want it, create a new cast at IP.
+          // Likewise, do not reuse a cast at BIP because it must dominate
+          // instructions that might be inserted before BIP.
           if (BasicBlock::iterator(CI) != IP || BIP == IP) {
             // Create a new cast, and leave the old cast in place in case
             // it is being used as an insert point. Clear its operand