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Bug ID: JDK-6746907 Improve implicit null check generatation
JDK-6746907 : Improve implicit null check generatation

Details
Type:
Enhancement
Submit Date:
2008-09-10
Status:
Resolved
Updated Date:
2010-04-03
Project Name:
JDK
Resolved Date:
2008-09-23
Component:
hotspot
OS:
solaris_10
Sub-Component:
compiler
CPU:
sparc
Priority:
P4
Resolution:
Fixed
Affected Versions:
hs14
Fixed Versions:
hs14 (b05)

Related Reports
Backport:
Backport:

Sub Tasks

Description
VM doesn't generate implicit null check if there are empty blocks
between null test and uncommon_trap call.
Also VM specifies the holder of a tested oop in uncommon_trap's debug info
instead of passing NULL. This increase registers pressure.

                                    

Comments
EVALUATION

http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/c792b641b8bd
                                     
2008-09-11
SUGGESTED FIX

Skip over empty blocks when looking for uncommon_trap
and add the missing offset check for compressed oops when
looking for an implicit null check opportunities.
Use NULL as value for a tested oop in uncommon_trap's debug info.
                                     
2008-09-11



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