commit 409443b1c6415e55c2bd4f0662e14cbc52d16686
author Andrew Trick <atrick@apple.com> Sun Jul 14 02:50:07 2013 +0000
committer Andrew Trick <atrick@apple.com> Sun Jul 14 02:50:07 2013 +0000
tree 4c44daac6c0deed9a387cb2b9fd05dea7eb8487f
parent 181a289256d8276ffe247405b521074f9947a124

Teach indvars to generate nsw/nuw flags when widening an induction variable.

Fixes PR16600.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186272 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/ScalarEvolutionExpander.cpp

diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp
index fcd7ce2..0dd1043 100644
--- a/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -1137,7 +1137,12 @@
       IVIncInsertPos : Pred->getTerminator();
     Builder.SetInsertPoint(InsertPos);
     Value *IncV = expandIVInc(PN, StepV, L, ExpandTy, IntTy, useSubtract);
-
+    if (isa<OverflowingBinaryOperator>(IncV)) {
+      if (Normalized->getNoWrapFlags(SCEV::FlagNUW))
+        cast<BinaryOperator>(IncV)->setHasNoUnsignedWrap();
+      if (Normalized->getNoWrapFlags(SCEV::FlagNSW))
+        cast<BinaryOperator>(IncV)->setHasNoSignedWrap();
+    }
     PN->addIncoming(IncV, Pred);
   }