From 409443b1c6415e55c2bd4f0662e14cbc52d16686 Mon Sep 17 00:00:00 2001
From: Andrew Trick <atrick@apple.com>
Date: Sun, 14 Jul 2013 02:50:07 +0000
Subject: 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 | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

(limited to 'lib')

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 @@ SCEVExpander::getAddRecExprPHILiterally(const SCEVAddRecExpr *Normalized,
       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);
   }
 
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