openjdk-11/prohibition-of-irreducible-loop-in-mergers.patch
2020-04-26 19:46:07 +08:00

28 lines
1.1 KiB
Diff

From fd0b27781fdc8a8d4089aeca7acfcaf7cfb1a82c Mon Sep 17 00:00:00 2001
Date: Thu, 19 Mar 2020 15:07:23 +0800
Subject: [PATCH] prohibition of irreducible loop in mergers
Summary: C2Compiler: irreducible loop should not enter merge_many_backedges
LLT: NA
Bug url: NA
---
src/hotspot/share/opto/loopnode.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/hotspot/share/opto/loopnode.cpp b/src/hotspot/share/opto/loopnode.cpp
index da81c3a5d..5c01a44e4 100644
--- a/src/hotspot/share/opto/loopnode.cpp
+++ b/src/hotspot/share/opto/loopnode.cpp
@@ -2089,7 +2089,7 @@ bool IdealLoopTree::beautify_loops( PhaseIdealLoop *phase ) {
// If I am a shared header (multiple backedges), peel off the many
// backedges into a private merge point and use the merge point as
// the one true backedge.
- if( _head->req() > 3 ) {
+ if( _head->req() > 3 && !_irreducible ) {
// Merge the many backedges into a single backedge but leave
// the hottest backedge as separate edge for the following peel.
merge_many_backedges( phase );
--
2.12.3