Bug 203550

Summary:

[JSC] DateMath should have TimeClipped version

Product:

WebKit

Reporter:

Yusuke Suzuki <ysuzuki>

Component:

JavaScriptCore

Assignee:

Yusuke Suzuki <ysuzuki>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

benjamin, cdumez, cmarcelo, dbates, ews-watchlist, keith_miller, mark.lam, msaboff, saam, tzagallo, webkit-bug-importer

Priority:

Keywords:

InRadar

Version:

WebKit Nightly Build

Hardware:

Unspecified

OS:

Unspecified

Bug Depends on:

202187

Bug Blocks:

Attachments:

Description	Flags
Patch	none
Patch	none
Patch	none
Patch	saam: review+

Yusuke Suzuki

Reported 2019-10-28 21:10:51 PDT

ECMAScript uses milliseconds (double) as its internal representation, but Date constructor and its operation clips this double before actually using it. As a result, this milliseconds is always within 53bit, and it is always integer. This means that we should use int64_t when calculating GregorianDateTime. When running instruments profiler, 31% of time is consumed by `fmod`. This is really fun, we should use integers instead.

Attachments
Patch (32.47 KB, patch) 2019-10-29 18:34 PDT, Yusuke Suzuki	no flags	Details Formatted Diff Diff
Patch (34.99 KB, patch) 2019-10-29 20:02 PDT, Yusuke Suzuki	no flags	Details Formatted Diff Diff
Patch (34.33 KB, patch) 2019-10-29 20:09 PDT, Yusuke Suzuki	no flags	Details Formatted Diff Diff
Patch (32.54 KB, patch) 2019-10-30 19:32 PDT, Yusuke Suzuki	saam: review+	Details Formatted Diff Diff
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