From 59de33ef3934eb98f0c5dfbfb2c56fb4b80bda56 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Fri, 18 Dec 2009 18:45:31 +0000 Subject: [PATCH] Revert this use of NUW/NSW also. Overflow-undefined multiplication isn't associative either. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91701 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/ScalarEvolution.cpp | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp index 3c937e05cc5..ec901b77ccc 100644 --- a/lib/Analysis/ScalarEvolution.cpp +++ b/lib/Analysis/ScalarEvolution.cpp @@ -1460,7 +1460,10 @@ const SCEV *ScalarEvolution::getAddExpr(SmallVectorImpl &Ops, AddRec->op_end()); AddRecOps[0] = getAddExpr(LIOps); + // It's tempting to propogate NUW/NSW flags here, but nuw/nsw addition + // is not associative so this isn't necessarily safe. const SCEV *NewRec = getAddRecExpr(AddRecOps, AddRec->getLoop()); + // If all of the other operands were loop invariant, we are done. if (Ops.size() == 1) return NewRec; @@ -1636,9 +1639,9 @@ const SCEV *ScalarEvolution::getMulExpr(SmallVectorImpl &Ops, } } - const SCEV *NewRec = getAddRecExpr(NewOps, AddRec->getLoop(), - AddRec->hasNoUnsignedWrap() && HasNUW, - AddRec->hasNoSignedWrap() && HasNSW); + // It's tempting to propogate NUW/NSW flags here, but nuw/nsw multiplication + // is not associative so this isn't necessarily safe. + const SCEV *NewRec = getAddRecExpr(NewOps, AddRec->getLoop()); // If all of the other operands were loop invariant, we are done. if (Ops.size() == 1) return NewRec;