JSStackFrame Evisceration: Difference between revisions

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| [https://bugzilla.mozilla.org/show_bug.cgi?id=535912 blockChain]
| [https://bugzilla.mozilla.org/show_bug.cgi?id=535912 blockChain]
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| 1
| lw
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| A bit tricky
| A bit tricky
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Revision as of 06:00, 5 August 2010

This would leave sizeof(JSStackFrame) == 6 words.

Members to remove

Sorted in estimated order of benefit / difficulty:

Task Size (wks) Assignee Note
argc/argv 1.5 lw Requires CallSegment (CallStack) changes, educate decompiler
thisv .5 lw Depends on argv/argc
fun, script .5 lw Depends on thisv
ncode 3 dvander Merge it with savedPC in method-jit. Requires building map HW PC --> bytecode (which we sortof already heave
XdisplaySave 1 cdleary Remove display optimization for great justice!
hookData 1 Once we are inlining call paths, we can know statically, based on the compartment-wide 'debug mode' flag, whether we can just ignore cx->debugHooks->callHook and leave hookData uninitialized. To actually remove the JSStackFrame member (without having the size depend on whether we are in debug mode or not), we can maintain a debugHook stack on the side.
annotation 3 sayrer Trivial if we can remove callers in nsScriptSecurityManager. Alas, that is not trivial, so this is going to take a while.
callerVersion .5 cdleary Mostly the challenge is just understanding the actual use case.
blockChain 1 A bit tricky
rval 1 Tricky
imacpc 1 cdleary Leave uninitialized in call path and use JSStackFrame::flags to indicate whether there is or is not an imacpc.

Method-jit changes

  • PIC for fast natives calls
  • PIC/fast path for interpreted inline call