[llvm-commits] [llvm] r141470 - /llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp

[Andrew Trick]

Author: atrick
Date: Fri Oct  7 21:16:39 2011
New Revision: 141470

URL: http://llvm.org/viewvc/llvm-project?rev=141470&view=rev
Log:
Add an extra safety check in front of the optimization in r141442.

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=141470&r1=141469&r2=141470&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp Fri Oct  7 21:16:39 2011
@@ -908,6 +908,15 @@
       if (IncV->getType() != Type::getInt1PtrTy(SE.getContext(), AS)
           && IncV->getType() != Type::getInt8PtrTy(SE.getContext(), AS))
         return false;
+      // Ensure the operands dominate the insertion point. I don't know of a
+      // case when this would not be true, so this is somewhat untested.
+      if (L == IVIncInsertLoop) {
+        for (User::op_iterator OI = IncV->op_begin()+1,
+               OE = IncV->op_end(); OI != OE; ++OI)
+          if (Instruction *OInst = dyn_cast<Instruction>(OI))
+            if (!SE.DT->dominates(OInst, IVIncInsertPos))
+              return false;
+      }
       break;
     }
     IncV = dyn_cast<Instruction>(IncV->getOperand(0));