JDK-6462850 : generate biased locking code in C2 ideal graph
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 7
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • OS: solaris_10
  • CPU: x86
  • Submitted: 2006-08-23
  • Updated: 2010-04-03
  • Resolved: 2008-11-19
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JDK 6 JDK 7 Other
6u14Fixed 7Fixed hs14Fixed
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.

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.

EVALUATION http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/a1980da045cc

EVALUATION Improve jbb performance.