From 56caa098085977c14cfab39d92c7dfa15dde0d90 Mon Sep 17 00:00:00 2001
From: Andrew Trick <atrick@apple.com>
Date: Tue, 28 Jun 2011 03:01:46 +0000
Subject: [PATCH] indvars --disable-iv-rewrite: sever ties with IVUsers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133988 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/IVUsers.cpp                 | 15 ---------------
 lib/Transforms/Scalar/IndVarSimplify.cpp | 12 ++++++------
 2 files changed, 6 insertions(+), 21 deletions(-)

diff --git a/lib/Analysis/IVUsers.cpp b/lib/Analysis/IVUsers.cpp
index ba4419c95d9..7a9dc0f14c2 100644
--- a/lib/Analysis/IVUsers.cpp
+++ b/lib/Analysis/IVUsers.cpp
@@ -21,7 +21,6 @@
 #include "llvm/Analysis/Dominators.h"
 #include "llvm/Analysis/LoopPass.h"
 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
-#include "llvm/Support/CommandLine.h"
 #include "llvm/Target/TargetData.h"
 #include "llvm/Assembly/Writer.h"
 #include "llvm/ADT/STLExtras.h"
@@ -39,15 +38,6 @@ INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
 INITIALIZE_PASS_END(IVUsers, "iv-users",
                       "Induction Variable Users", false, true)
 
-// IVUsers behavior currently depends on this temporary indvars mode. The
-// option must be defined upstream from its uses.
-namespace llvm {
-  bool DisableIVRewrite = false;
-}
-cl::opt<bool, true> DisableIVRewriteOpt(
-  "disable-iv-rewrite", cl::Hidden, cl::location(llvm::DisableIVRewrite),
-  cl::desc("Disable canonical induction variable rewriting"));
-
 Pass *llvm::createIVUsersPass() {
   return new IVUsers();
 }
@@ -100,11 +90,6 @@ bool IVUsers::AddUsersIfInteresting(Instruction *I) {
   if (Width > 64 || (TD && !TD->isLegalInteger(Width)))
     return false;
 
-  // We expect Sign/Zero extension to be eliminated from the IR before analyzing
-  // any downstream uses.
-  if (DisableIVRewrite && (isa<SExtInst>(I) || isa<ZExtInst>(I)))
-    return false;
-
   if (!Processed.insert(I))
     return true;    // Instruction already handled.
 
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index 126dbfdd200..587638030c4 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -52,6 +52,7 @@
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/LoopPass.h"
 #include "llvm/Support/CFG.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Utils/Local.h"
@@ -72,11 +73,9 @@ STATISTIC(NumElimExt     , "Number of IV sign/zero extends eliminated");
 STATISTIC(NumElimRem     , "Number of IV remainder operations eliminated");
 STATISTIC(NumElimCmp     , "Number of IV comparisons eliminated");
 
-// DisableIVRewrite mode currently affects IVUsers, so is defined in libAnalysis
-// and referenced here.
-namespace llvm {
-  extern bool DisableIVRewrite;
-}
+static cl::opt<bool> DisableIVRewrite(
+  "disable-iv-rewrite", cl::Hidden,
+  cl::desc("Disable canonical induction variable rewriting"));
 
 namespace {
   class IndVarSimplify : public LoopPass {
@@ -104,7 +103,8 @@ namespace {
       AU.addRequired<ScalarEvolution>();
       AU.addRequiredID(LoopSimplifyID);
       AU.addRequiredID(LCSSAID);
-      AU.addRequired<IVUsers>();
+      if (!DisableIVRewrite)
+        AU.addRequired<IVUsers>();
       AU.addPreserved<ScalarEvolution>();
       AU.addPreservedID(LoopSimplifyID);
       AU.addPreservedID(LCSSAID);
-- 
2.11.0