From: Hans Wennborg <hans@hanshq.net>
Date: Thu, 23 Feb 2017 22:29:00 +0000 (+0000)
Subject: Revert r282872 "CVP. Turn marking adds as no wrap on by default"
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b20570e64734b73fce02d5e4fd3a400c6015d7da;p=llvm

Revert r282872 "CVP. Turn marking adds as no wrap on by default"

While not CVP's fault, this caused miscompiles (PR31181). Reverting
until those are resolved.

(This also reverts the follow-ups r288154 and r288161 which removed the
flag.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296030 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp b/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
index 60786a3373f..d4d5ef4b158 100644
--- a/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
+++ b/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
@@ -41,6 +41,8 @@ STATISTIC(NumSDivs,     "Number of sdiv converted to udiv");
 STATISTIC(NumAShrs,     "Number of ashr converted to lshr");
 STATISTIC(NumSRems,     "Number of srem converted to urem");
 
+static cl::opt<bool> DontProcessAdds("cvp-dont-process-adds", cl::init(true));
+
 namespace {
   class CorrelatedValuePropagation : public FunctionPass {
   public:
@@ -405,6 +407,9 @@ static bool processAShr(BinaryOperator *SDI, LazyValueInfo *LVI) {
 static bool processAdd(BinaryOperator *AddOp, LazyValueInfo *LVI) {
   typedef OverflowingBinaryOperator OBO;
 
+  if (DontProcessAdds)
+    return false;
+
   if (AddOp->getType()->isVectorTy() || hasLocalDefs(AddOp))
     return false;
 
diff --git a/test/Transforms/CorrelatedValuePropagation/add.ll b/test/Transforms/CorrelatedValuePropagation/add.ll
index 4b436ff9a40..0ba521c894e 100644
--- a/test/Transforms/CorrelatedValuePropagation/add.ll
+++ b/test/Transforms/CorrelatedValuePropagation/add.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -correlated-propagation -S | FileCheck %s
+; RUN: opt < %s -correlated-propagation -cvp-dont-process-adds=false -S | FileCheck %s
 
 ; CHECK-LABEL: @test0(
 define void @test0(i32 %a) {