From 721c201bd55ffb73cb2ba8d39e0570fa38c44e15 Mon Sep 17 00:00:00 2001
From: dim <dim@FreeBSD.org>
Date: Wed, 15 Aug 2012 19:34:23 +0000
Subject: Vendor import of llvm trunk r161861:
http://llvm.org/svn/llvm-project/llvm/trunk@161861
---
lib/Analysis/IVUsers.cpp | 7 +++++++
1 file changed, 7 insertions(+)
(limited to 'lib/Analysis/IVUsers.cpp')
diff --git a/lib/Analysis/IVUsers.cpp b/lib/Analysis/IVUsers.cpp
index b80966b..0a6682a 100644
--- a/lib/Analysis/IVUsers.cpp
+++ b/lib/Analysis/IVUsers.cpp
@@ -21,6 +21,7 @@
#include "llvm/Analysis/Dominators.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
+#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/ADT/STLExtras.h"
@@ -120,6 +121,12 @@ bool IVUsers::AddUsersImpl(Instruction *I,
if (!SE->isSCEVable(I->getType()))
return false; // Void and FP expressions cannot be reduced.
+ // IVUsers is used by LSR which assumes that all SCEV expressions are safe to
+ // pass to SCEVExpander. Expressions are not safe to expand if they represent
+ // operations that are not safe to speculate, namely integer division.
+ if (!isa<PHINode>(I) && !isSafeToSpeculativelyExecute(I, TD))
+ return false;
+
// LSR is not APInt clean, do not touch integers bigger than 64-bits.
// Also avoid creating IVs of non-native types. For example, we don't want a
// 64-bit IV in 32-bit code just because the loop has one 64-bit cast.
--
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