[llvm-commits] [llvm] r39839 - /llvm/trunk/lib/Transforms/Scalar/FastDSE.cpp

[Owen Anderson]

Author: resistor
Date: Fri Jul 13 17:50:48 2007
New Revision: 39839

URL: http://llvm.org/viewvc/llvm-project?rev=39839&view=rev
Log:
Handle GEPs with all-zero indices in the same way we handle pointer-pointer bitcasts. Also, fix a potentia infinite loop.

This brings FastDSE to parity with old DSE on 175.vpr.

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

Modified: llvm/trunk/lib/Transforms/Scalar/FastDSE.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/FastDSE.cpp?rev=39839&r1=39838&r2=39839&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/FastDSE.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/FastDSE.cpp Fri Jul 13 17:50:48 2007
@@ -60,9 +60,18 @@
       assert(isa<PointerType>(v->getType()) && "Translating a non-pointer type?");
       
       // See through pointer-to-pointer bitcasts
-      while (BitCastInst* C = dyn_cast<BitCastInst>(v))
-        if (isa<PointerType>(C->getSrcTy()))
-          v = C->getOperand(0);
+      while (isa<BitCastInst>(v) || isa<GetElementPtrInst>(v))
+        if (BitCastInst* C = dyn_cast<BitCastInst>(v)) {
+          if (isa<PointerType>(C->getSrcTy()))
+            v = C->getOperand(0);
+          else
+            break;
+        } else if (GetElementPtrInst* G = dyn_cast<GetElementPtrInst>(v)) {
+          if (G->hasAllZeroIndices())
+            v = G->getOperand(0);
+          else
+            break;
+        }
     }
 
     // getAnalysisUsage - We require post dominance frontiers (aka Control