Closed
Bug 818414
Opened 13 years ago
Closed 13 years ago
CodeGenerator::visitValueToInt32 generates suboptimal code
Categories
(Core :: JavaScript Engine, defect)
Tracking
()
RESOLVED
FIXED
mozilla20
People
(Reporter: bzbarsky, Assigned: evilpies)
Details
Attachments
(1 file)
|
4.16 KB,
patch
|
jandem
:
review+
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Details | Diff | Splinter Review |
From JIT Inspector output:
movq %rcx, %r11
shrq $47, %r11
cmpl $0x1fff1, %r11d
je ((1014))
movq %rcx, %r11
shrq $47, %r11
cmpl $0x1fff3, %r11d
je ((1034))
movq %rcx, %r11
shrq $47, %r11
cmpl $0x1fff0, %r11d
ja ((1054))
The repeated movq/shrq are totally unnecessary, afaict.
And later on after some maybe-jumps and a bit of playing with the xmm registers there's more of the same:
movq %rcx, %r11
shrq $47, %r11
cmpl $0x1fff6, %r11d
jne ((1111))
Seems like grabbing the tag once, then testing repeatedly, would be nicer...
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Assignee | |
Comment 1•13 years ago
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Boris, good work, keep them coming. Looks like there are quite a few things that can be optimized when you actually look at the generated code.
Attachment #688905 -
Flags: review?(jdemooij)
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Assignee | |
Updated•13 years ago
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Assignee: general → evilpies
Status: NEW → ASSIGNED
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Comment 2•13 years ago
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Comment on attachment 688905 [details] [diff] [review]
v1
Review of attachment 688905 [details] [diff] [review]:
-----------------------------------------------------------------
Good catch.
Attachment #688905 -
Flags: review?(jdemooij) → review+
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Assignee | |
Comment 3•13 years ago
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Assignee | |
Comment 4•13 years ago
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Ups sorry, wrong link...
https://hg.mozilla.org/integration/mozilla-inbound/rev/78c7f99089ea
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Comment 5•13 years ago
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Status: ASSIGNED → RESOLVED
Closed: 13 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla20
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Description
•