Delete code for folding undefs in ScalarEvolution. It's invalid in

obscure ways, and it isn't actually important in the real world.

llvm-svn: 159969

1 files changed, 0 insertions, 14 deletions

diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index b8c92f83d9f..884ceec7a00 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -878,13 +878,6 @@ const SCEV *ScalarEvolution::getTruncateExpr(const SCEV *Op,
     return getAddRecExpr(Operands, AddRec->getLoop(), SCEV::FlagAnyWrap);
   }
 
-  // As a special case, fold trunc(undef) to undef. We don't want to
-  // know too much about SCEVUnknowns, but this special case is handy
-  // and harmless.
-  if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(Op))
-    if (isa<UndefValue>(U->getValue()))
-      return getSCEV(UndefValue::get(Ty));
-
   // The cast wasn't folded; create an explicit cast node. We can reuse
   // the existing insert position since if we get here, we won't have
   // made any changes which would invalidate it.
@@ -1344,13 +1337,6 @@ const SCEV *ScalarEvolution::getAnyExtendExpr(const SCEV *Op,
     return getAddRecExpr(Ops, AR->getLoop(), SCEV::FlagNW);
   }
 
-  // As a special case, fold anyext(undef) to undef. We don't want to
-  // know too much about SCEVUnknowns, but this special case is handy
-  // and harmless.
-  if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(Op))
-    if (isa<UndefValue>(U->getValue()))
-      return getSCEV(UndefValue::get(Ty));
-
   // If the expression is obviously signed, use the sext cast value.
   if (isa<SCEVSMaxExpr>(Op))
     return SExt;