Bug 121916

Summary:

Get rid of 2 unused parameters from ctiTrampoline function in baseline JIT.

Product:

WebKit

Reporter:

Julien Brianceau <jbriance>

Component:

JavaScriptCore

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED WONTFIX

Severity:

Normal

CC:

buildbot, fpizlo, ggaren, kilvadyb, msaboff, oliver, ossy, rgabor, rniwa

Priority:

Version:

528+ (Nightly build)

Hardware:

Unspecified

OS:

Unspecified

Attachments:

Description	Flags
Get rid of 2 unused parameters from ctiTrampoline function in baseline JIT.	webkit-ews: commit-queue-
Get rid of 2 unused parameters from ctiTrampoline function in baseline JIT (2nd try)	none

Julien Brianceau

Reported 2013-09-25 10:30:13 PDT

Remove the 2 unused void* parameters from ctiTrampoline function in baseline JIT. With current implementation in baseline JIT, architectures using 4 argument registers (sh4 and mips for instance) are pushing 2 words on stack for each call to ctiTrampoline: the void* unused2 and the VM* parameters.

Attachments
Get rid of 2 unused parameters from ctiTrampoline function in baseline JIT. (4.17 KB, patch) 2013-09-25 10:42 PDT, Julien Brianceau	webkit-ews: commit-queue-	Details Formatted Diff Diff
Get rid of 2 unused parameters from ctiTrampoline function in baseline JIT (2nd try) (5.57 KB, patch) 2013-09-25 12:05 PDT, Julien Brianceau	no flags	Details Formatted Diff Diff
Show Obsolete (2) View All Add attachment proposed patch, testcase, etc.

Julien Brianceau

Comment 1 2013-09-25 10:42:19 PDT

Created attachment 212600 [details] Get rid of 2 unused parameters from ctiTrampoline function in baseline JIT. I get 2.5% speed up on my (slow) sh4 platform with this patch, and this patch didn't break anything on my mips platform. As I don't have ready environments to test this patch properly on all other architectures (ARM, X86 & X86_64), please do not cq+ this patch right now.

Early Warning System Bot

Comment 2 2013-09-25 10:52:26 PDT

Comment on attachment 212600 [details] Get rid of 2 unused parameters from ctiTrampoline function in baseline JIT. Attachment 212600 [details] did not pass qt-ews (qt): Output: http://webkit-queues.appspot.com/results/2235171

Early Warning System Bot

Comment 3 2013-09-25 10:56:57 PDT

Comment on attachment 212600 [details] Get rid of 2 unused parameters from ctiTrampoline function in baseline JIT. Attachment 212600 [details] did not pass qt-wk2-ews (qt-wk2): Output: http://webkit-queues.appspot.com/results/2219005

Build Bot

Comment 4 2013-09-25 11:07:35 PDT

Comment on attachment 212600 [details] Get rid of 2 unused parameters from ctiTrampoline function in baseline JIT. Attachment 212600 [details] did not pass mac-wk2-ews (mac-wk2): Output: http://webkit-queues.appspot.com/results/2281045

Build Bot

Comment 5 2013-09-25 11:07:54 PDT

Comment on attachment 212600 [details] Get rid of 2 unused parameters from ctiTrampoline function in baseline JIT. Attachment 212600 [details] did not pass mac-ews (mac): Output: http://webkit-queues.appspot.com/results/2220004

Julien Brianceau

Comment 6 2013-09-25 11:58:15 PDT

Comment on attachment 212600 [details] Get rid of 2 unused parameters from ctiTrampoline function in baseline JIT. Oops, I forget to update savedRBX offset for X86_64

Julien Brianceau

Comment 7 2013-09-25 12:05:14 PDT

Created attachment 212611 [details] Get rid of 2 unused parameters from ctiTrampoline function in baseline JIT (2nd try) Should be better

Filip Pizlo

Comment 8 2013-09-25 12:16:32 PDT

I think those are reserved for DFG-style native calls. msaboff and I are about to make the baseline JIT use that calling convention also. So not only is this likely to break the DFG but it will get rolled out once we fix the baseline JIT. Or are you sure that arguments to functions that take more than 4 parameters are passed through some other set of slots?

Julien Brianceau

Comment 9 2013-09-25 12:39:55 PDT

(In reply to comment #8) > I think those are reserved for DFG-style native calls. msaboff and I are about to make the baseline JIT use that calling convention also. So not only is this likely to break the DFG but it will get rolled out once we fix the baseline JIT. Ok it'd better to wait your change in baseline JIT then.

Julien Brianceau

Comment 10 2013-11-09 09:02:42 PST

Closing bug, this change is no more relevant since r158751 (https://bugs.webkit.org/show_bug.cgi?id=123844)

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