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Bug ID: 6462850 generate biased locking code in C2 ideal graph
6462850 : generate biased locking code in C2 ideal graph

Details
Type:
Enhancement
Submit Date:
2006-08-23
Status:
Resolved
Updated Date:
2010-04-03
Project Name:
JDK
Resolved Date:
2008-11-19
Component:
hotspot
OS:
solaris_10
Sub-Component:
compiler
CPU:
x86
Priority:
P4
Resolution:
Fixed
Affected Versions:
7
Fixed Versions:
hs14

Related Reports
Backport:
JDK-2177348 - generate biased locking code in C2 ideal graph
Backport:
JDK-2172822 - generate biased locking code in C2 ideal graph

Sub Tasks

Description
The short branches could be used in biased locking code on x86 and amd64
to reduce the code size.
Use this bug for next optimization:
Generate biased locking code in C2 ideal graph instead of
using FastLock/FastUnlock mach nodes.

Comments
EVALUATION

http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/a1980da045cc
2008-11-07 
SUGGESTED FIX

Solution:
- Inline biased locking code in C2 ideal graph during
macro nodes expansion. Use new flag UseOptoBiasInlining to gate
new code. Set the flag ON by default.
- Add new ideal node StoreIConditional and use existing
StoreLConditional node for cas stores into object's mark word.
Fix implementation of StoreLConditional for that.
- Allow tlsLoadP mach node to return a value in any P
register on x86 32-bits (instead of only EAX).
- Added new OR mach node to avoid casting of TLS pointer.

Additional fixes:
- Delay a memory node igvn transformation until its address
is processed (the fix for the problem described in 6759776).
- Add missing check for the lock code on x86 into
Assembler::locate_operand().
- Pin a SafePointScalarObject node to the control edge of
the SafePoint node for which it was generated.
- Fix size's format in OutOfMemoryError message.
2008-11-07 
EVALUATION

Improve jbb performance.
2008-10-30


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