From: Chris Lattner <sabre@nondot.org>
Date: Mon, 2 Apr 2007 22:51:58 +0000 (+0000)
Subject: allow -1 strides to reuse "1" strides.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1d31290634eccc3b360c427282d59780d76b9169;p=oota-llvm.git

allow -1 strides to reuse "1" strides.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35607 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 744e0548bad..db8ab485e39 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -929,7 +929,8 @@ unsigned LoopStrengthReduce::CheckForIVReuse(const SCEVHandle &Stride,
     for (std::map<SCEVHandle, IVsOfOneStride>::iterator SI= IVsByStride.begin(),
            SE = IVsByStride.end(); SI != SE; ++SI) {
       int64_t SSInt = cast<SCEVConstant>(SI->first)->getValue()->getSExtValue();
-      if (unsigned(abs(SInt)) < SSInt || (SInt % SSInt) != 0)
+      if (SInt != -SSInt &&
+          (unsigned(abs(SInt)) < SSInt || (SInt % SSInt) != 0))
         continue;
       int64_t Scale = SInt / SSInt;
       // Check that this stride is valid for all the types used for loads and