From 5272c3b1e1035b67b7741d54000d91438a5b4ef8 Mon Sep 17 00:00:00 2001
From: Ariel Ben-Yehuda <ariel.byd@gmail.com>
Date: Thu, 14 Dec 2017 21:38:03 -0600
Subject: [PATCH] Simplify CFG between IndVarSimplify and LoopIdiomRecognize

This ensures that information is properly propagated when IndVarSimplify
removes an overflow check.
---
 lib/Transforms/IPO/PassManagerBuilder.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp
index 260b2283b311..69159445d135 100644
--- a/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -315,6 +315,7 @@ void PassManagerBuilder::addFunctionSimplificationPasses(
   MPM.add(createCFGSimplificationPass());
   addInstructionCombiningPass(MPM);
   MPM.add(createIndVarSimplifyPass());        // Canonicalize indvars
+  MPM.add(createCFGSimplificationPass());     // Clean up after IndVarSimplify.
   MPM.add(createLoopIdiomPass());             // Recognize idioms like memset.
   MPM.add(createLoopDeletionPass());          // Delete dead loops
   if (EnableLoopInterchange) {