openjdk-1.8.0/prohibition-of-irreducible-loop-in-mergers.patch
2020-03-21 11:30:48 +08:00

28 lines
1.1 KiB
Diff

From 34712f6bbc3c2c664ee641c78d4a2f8cfe427880 Mon Sep 17 00:00:00 2001
Date: Fri, 28 Feb 2020 15:17:44 +0000
Subject: [PATCH] prohibition of irreducible loop in mergers
Summary: C2Compiler: irreducible loop should not enter merge_many_backedges
LLT: NA
Bug url: NA
---
hotspot/src/share/vm/opto/loopnode.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hotspot/src/share/vm/opto/loopnode.cpp b/hotspot/src/share/vm/opto/loopnode.cpp
index e2c0645cf8..bbb2e2bf98 100644
--- a/hotspot/src/share/vm/opto/loopnode.cpp
+++ b/hotspot/src/share/vm/opto/loopnode.cpp
@@ -1542,7 +1542,7 @@ 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