From: Cameron Zwarich <zwarich@apple.com>
Date: Thu, 10 Feb 2011 01:07:54 +0000 (+0000)
Subject: Turn this pass ordering:
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=de0c42a73ac0787921d0020238af309f4b91451f;p=llvm

Turn this pass ordering:

Natural Loop Information
 Loop Pass Manager
   Canonicalize natural loops
 Scalar Evolution Analysis
 Loop Pass Manager
   Induction Variable Users
   Canonicalize natural loops
   Induction Variable Users
   Loop Strength Reduction

into this:

Scalar Evolution Analysis
Loop Pass Manager
  Canonicalize natural loops
  Induction Variable Users
  Loop Strength Reduction

This fixes <rdar://problem/8869639>. I also filed PR9184 on doing this sort of
thing automatically, but it seems easier to just change the ordering of the
passes if this is the only case.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125254 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 01dcfaf0652..dcee08b5238 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -3815,15 +3815,15 @@ LoopStrengthReduce::LoopStrengthReduce(const TargetLowering *tli)
 void LoopStrengthReduce::getAnalysisUsage(AnalysisUsage &AU) const {
   // We split critical edges, so we change the CFG.  However, we do update
   // many analyses if they are around.
-  AU.addPreservedID(LoopSimplifyID);
 
-  AU.addRequired<LoopInfo>();
-  AU.addPreserved<LoopInfo>();
-  AU.addRequiredID(LoopSimplifyID);
   AU.addRequired<DominatorTree>();
   AU.addPreserved<DominatorTree>();
   AU.addRequired<ScalarEvolution>();
   AU.addPreserved<ScalarEvolution>();
+  AU.addRequired<LoopInfo>();
+  AU.addPreserved<LoopInfo>();
+  AU.addRequiredID(LoopSimplifyID);
+  AU.addPreservedID(LoopSimplifyID);
   AU.addRequired<IVUsers>();
   AU.addPreserved<IVUsers>();
 }