[llvm-commits] [llvm] r139450 - /llvm/trunk/lib/Analysis/ScalarEvolution.cpp

[Andrew Trick]

Author: atrick
Date: Fri Sep  9 20:09:50 2011
New Revision: 139450

URL: http://llvm.org/viewvc/llvm-project?rev=139450&view=rev
Log:
Set NSW/NUW flags on SCEVAddExpr when the operation is flagged as
such.

I'm doing this now for completeness because I can't think of/remember
any reason that it was left out. I'm not sure it will help anything,
but if we don't do it we need to explain why in comments.

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

Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=139450&r1=139449&r2=139450&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Fri Sep  9 20:09:50 2011
@@ -3546,7 +3546,13 @@
         AddOps.push_back(Op1);
     }
     AddOps.push_back(getSCEV(U->getOperand(0)));
-    return getAddExpr(AddOps);
+    SCEV::NoWrapFlags Flags = SCEV::FlagAnyWrap;
+    OverflowingBinaryOperator *OBO = cast<OverflowingBinaryOperator>(V);
+    if (OBO->hasNoSignedWrap())
+      setFlags(Flags, SCEV::FlagNSW);
+    if (OBO->hasNoUnsignedWrap())
+      setFlags(Flags, SCEV::FlagNUW);
+    return getAddExpr(AddOps, Flags);
   }
   case Instruction::Mul: {
     // See the Add code above.