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Bug ID: 6837094 False positive for "meet not symmetric" failure
6837094 : False positive for "meet not symmetric" failure

Details
Type:
Bug
Submit Date:
2009-05-04
Status:
Closed
Updated Date:
2011-03-08
Project Name:
JDK
Resolved Date:
2011-03-08
Component:
hotspot
OS:
solaris_10
Sub-Component:
compiler
CPU:
x86
Priority:
P3
Resolution:
Fixed
Affected Versions:
hs16
Fixed Versions:
hs16

Related Reports
Backport:
JDK-2180664 - False positive for "meet not symmetric" failure
Backport:
JDK-2180085 - False positive for "meet not symmetric" failure

Sub Tasks

Description
The attached java program, when compiled and run with debug -server VM, aborts with a "Meet Not Symmetric" failure.

% bin/java -Xbatch -server Test
=== Meet Not Symmetric ===
t   =                   Interface:TopPTR *,iid=top[int:max..0]
this=                   Parent:TopPTR *,iid=top[int:1]
mt=(t meet this)=       Interface:TopPTR *[int:1]
t_dual=                 Interface *[int:>=0]
this_dual=              Parent *[int:1]
mt_dual=                Interface *,iid=top[int:1]
mt_dual meet t_dual=    Interface *[int:>=0]
mt_dual meet this_dual= java/lang/Object *[int:1]
# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc:  SuppressErrorAt=/type.cpp:532
#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (/BUILD_AREA/jdk7/hotspot/src/share/vm/opto/type.cpp:532), pid=2342, tid=10
#  Error: meet not symmetric
#
# JRE version: 7.0-b57
# Java VM: Java HotSpot(TM) Server VM (16.0-b02-fastdebug mixed mode solaris-x86 )

Comments
EVALUATION

http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/915cc9c5ebc6
2009-06-24 
SUGGESTED FIX

Have the meet not symmetric check recursively do the interface-vs-oop
check on array subtypes.
2009-06-24 
EVALUATION

Chuck Rasbold wrote:

  In Type::meet(), there is a check to see if the meet is of the interface-type vs.
  oop-type variety.  If so, the symmetric check is sidestepped. However, the test
  program illustrates that the check is not skipped as it should be if the meet is
  between an array-of-interface vs. array-of-oop.
2009-05-04


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