Now that hasConstantValue has been made simpler, it may return the

phi node itself if it occurs in an unreachable basic block.  Protect
against this.  Hopefully this will fix some more buildbots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119493 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/Lint.cpp b/lib/Analysis/Lint.cpp
index e5e7cd38576fc56f6133c507f3e3b66e989bd006..0cdb4b1a1c91bf62d6ec413959ac72fcf6c11329 100644 (file)
--- a/lib/Analysis/Lint.cpp
+++ b/lib/Analysis/Lint.cpp
@@ -583,7 +583,8 @@ Value *Lint::findValueImpl(Value *V, bool OffsetOk,
     }
   } else if (PHINode *PN = dyn_cast<PHINode>(V)) {
     if (Value *W = PN->hasConstantValue())
-      return findValueImpl(W, OffsetOk, Visited);
+      if (W != V)
+        return findValueImpl(W, OffsetOk, Visited);
   } else if (CastInst *CI = dyn_cast<CastInst>(V)) {
     if (CI->isNoopCast(TD ? TD->getIntPtrType(V->getContext()) :
                             Type::getInt64Ty(V->getContext())))

diff --git a/lib/VMCore/BasicBlock.cpp b/lib/VMCore/BasicBlock.cpp
index 8ad53736c993f9c3c79e2737d1186bc8f50df76f..955a0285b2602056a68ea8dbee0eaa0b5d0e08a5 100644 (file)
--- a/lib/VMCore/BasicBlock.cpp
+++ b/lib/VMCore/BasicBlock.cpp
@@ -248,10 +248,11 @@ void BasicBlock::removePredecessor(BasicBlock *Pred,
       // If all incoming values to the Phi are the same, we can replace the Phi
       // with that value.
       Value* PNV = 0;
-      if (!DontDeleteUselessPHIs && (PNV = PN->hasConstantValue())) {
-        PN->replaceAllUsesWith(PNV);
-        PN->eraseFromParent();
-      }
+      if (!DontDeleteUselessPHIs && (PNV = PN->hasConstantValue()))
+        if (PNV != PN) {
+          PN->replaceAllUsesWith(PNV);
+          PN->eraseFromParent();
+        }
     }
   }
 }