Closed
Bug 1278623
Opened 8 years ago
Closed 8 years ago
Open-coded x86 popcnt32 computes the wrong result
Categories
(Core :: JavaScript Engine: JIT, defect)
Tracking
()
RESOLVED
FIXED
mozilla50
| Tracking | Status | |
|---|---|---|
| firefox50 | --- | fixed |
People
(Reporter: lth, Assigned: lth)
Details
Attachments
(1 file)
|
1.05 KB,
patch
|
bbouvier
:
review+
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Details | Diff | Splinter Review |
The reason is that tmp is used uninitialized (it should be initialized to input, I believe, but I will investigate properly). This may have been a merge bug or something like that, because I seem to remember that I did see the code do that previously. We're not seeing this because every machine we're testing on has the POPCNT instruction. cc'ing the (German) Inquisition.
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Assignee | |
Comment 1•8 years ago
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Note, this patch sits in the middle of my patch queue right now and the parent node ID in the patch does not exist in the Mozilla repos.
Attachment #8760837 -
Flags: review?(bbouvier)
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Assignee | |
Updated•8 years ago
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OS: Unspecified → All
Hardware: Unspecified → x86
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Assignee | |
Comment 2•8 years ago
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Popcnt appears to be wasm-only and no uplift should be necessary.
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Comment 3•8 years ago
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Comment on attachment 8760837 [details] [diff] [review] bug1278623-popcnt.patch Review of attachment 8760837 [details] [diff] [review]: ----------------------------------------------------------------- Great catch.
Attachment #8760837 -
Flags: review?(bbouvier) → review+
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Assignee | |
Comment 4•8 years ago
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https://hg.mozilla.org/integration/mozilla-inbound/rev/1ba05c136eec135032c0d5bf8faa86e697184177 Bug 1278623 - fix emulation of POPCNT on x86. r=bbouvier
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Comment 5•8 years ago
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| bugherder | ||
https://hg.mozilla.org/mozilla-central/rev/1ba05c136eec
Status: ASSIGNED → RESOLVED
Closed: 8 years ago
status-firefox50:
--- → fixed
Resolution: --- → FIXED
Target Milestone: --- → mozilla50
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Description
•