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Bug ID: JDK-6532536 Optimize arraycopy stubs for Intel cpus
JDK-6532536 : Optimize arraycopy stubs for Intel cpus

Details
Type:
Enhancement
Submit Date:
2007-03-08
Status:
Resolved
Updated Date:
2010-04-03
Project Name:
JDK
Resolved Date:
2008-11-04
Component:
hotspot
OS:
solaris_10
Sub-Component:
compiler
CPU:
x86
Priority:
P3
Resolution:
Fixed
Affected Versions:
7
Fixed Versions:
hs14 (b06)

Related Reports
Backport:
Backport:

Sub Tasks

Description
Intel cpus very sensitive to data moves alignment.
Arraycopy stubs have to be fixed to avoid such misalignment
for these hardware.
SSE2 movdqu nstruction performance was greatly improved on newest Intel's cpus.

                                    

Comments
EVALUATION

see comment.
                                     
2007-08-24
EVALUATION

http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/2649e5276dd7
                                     
2008-10-15
SUGGESTED FIX

- Use SSE2 movdqu in arraycopy stubs on newest Intel's cpus since
the instruction performance was greatly improved. It allows
to skip the code which align a copy source address.
- Use SSE2 movq instruction instead of MMX on Intel's Core2 cpus.
- Add CPUID check for newest Intel's cpus.
- Fix a cpu model number calculation.
                                     
2008-10-15



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