[llvm-commits] [llvm] r121886 - /llvm/trunk/lib/Analysis/ValueTracking.cpp

[Dan Gohman]

Author: djg
Date: Wed Dec 15 14:10:26 2010
New Revision: 121886

URL: http://llvm.org/viewvc/llvm-project?rev=121886&view=rev
Log:
Strengthen GetUnderlyingObject using InstructionSimplify.

While LLVM's main design is that analysis code shouldn't
go out of its way to understand code which hasn't been
InstCombined, analysis utility routines like this can
find themselves being called in the middle of transform
passes when instcombine hasn't had a chance to run.

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

Modified: llvm/trunk/lib/Analysis/ValueTracking.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ValueTracking.cpp?rev=121886&r1=121885&r2=121886&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ValueTracking.cpp (original)
+++ llvm/trunk/lib/Analysis/ValueTracking.cpp Wed Dec 15 14:10:26 2010
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Analysis/ValueTracking.h"
+#include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Constants.h"
 #include "llvm/Instructions.h"
 #include "llvm/GlobalVariable.h"
@@ -1440,6 +1441,14 @@
         return V;
       V = GA->getAliasee();
     } else {
+      // See if InstructionSimplify knows any relevant tricks.
+      if (Instruction *I = dyn_cast<Instruction>(V))
+        // TODO: Aquire TargetData and DominatorTree and use them.
+        if (Value *Simplified = SimplifyInstruction(I, 0, 0)) {
+          V = Simplified;
+          continue;
+        }
+
       return V;
     }
     assert(V->getType()->isPointerTy() && "Unexpected operand type!");