From: Mandeep Singh Grang <mgrang@codeaurora.org>
Date: Mon, 30 Oct 2017 19:42:41 +0000 (+0000)
Subject: [GVNHoist] Fix non-deterministic sort order of PHIs for identical instructions
X-Git-Tag: llvmorg-6.0.0-rc1~4563
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f83268bd9e2fd087d4396d3b63c87b2bd2641b68;p=platform%2Fupstream%2Fllvm.git

[GVNHoist] Fix non-deterministic sort order of PHIs for identical instructions

Summary: This fixes failure in Transforms/GVNHoist/hoist.ll uncovered by D39245.

Reviewers: hiraditya, spop, dberlin

Reviewed By: dberlin

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39410

llvm-svn: 316949
---

diff --git a/llvm/lib/Transforms/Scalar/GVNHoist.cpp b/llvm/lib/Transforms/Scalar/GVNHoist.cpp
index c13768d..d77ebdc 100644
--- a/llvm/lib/Transforms/Scalar/GVNHoist.cpp
+++ b/llvm/lib/Transforms/Scalar/GVNHoist.cpp
@@ -703,7 +703,7 @@ private:
       // Vector of PHIs contains PHIs for different instructions.
       // Sort the args according to their VNs, such that identical
       // instructions are together.
-      std::sort(CHIs.begin(), CHIs.end(), cmpVN);
+      std::stable_sort(CHIs.begin(), CHIs.end(), cmpVN);
       auto TI = BB->getTerminator();
       auto B = CHIs.begin();
       // [PreIt, PHIIt) form a range of CHIs which have identical VNs.