Bug 227201

Summary:

Add a new pattern to instruction selector to use BFI supported by ARM64

Product:

WebKit

Reporter:

Yijia Huang <yijia_huang>

Component:

JavaScriptCore

Assignee:

Yijia Huang <yijia_huang>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

ews-watchlist, fpizlo, kdaveport7, keith_miller, mark.lam, msaboff, saam, tzagallo, webkit-bug-importer, ysuzuki

Priority:

Version:

WebKit Nightly Build

Hardware:

Unspecified

OS:

Unspecified

Attachments:

Description	Flags
Patch	none
Patch	none
Patch	none
Patch	none

Yijia Huang

Reported 2021-06-20 21:51:58 PDT

...

Attachments
Patch (30.46 KB, patch) 2021-06-24 01:50 PDT, Yijia Huang	no flags	Details Formatted Diff Diff
Patch (23.51 KB, patch) 2021-06-24 10:20 PDT, Yijia Huang	no flags	Details Formatted Diff Diff
Patch (23.34 KB, patch) 2021-06-24 10:29 PDT, Yijia Huang	no flags	Details Formatted Diff Diff
Patch (25.79 KB, patch) 2021-06-24 13:31 PDT, Yijia Huang	no flags	Details Formatted Diff Diff
Show Obsolete (3) View All Add attachment proposed patch, testcase, etc.

Yijia Huang

Comment 1 2021-06-24 01:50:57 PDT

Created attachment 432140 [details] Patch

Filip Pizlo

Comment 2 2021-06-24 09:22:17 PDT

Comment on attachment 432140 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=432140&action=review > Source/JavaScriptCore/ChangeLog:28 > + Pattern 2: > + mask1 = (1 << width) - 1 > + mask2 = ~(mask1 << lsb) > + d = ((n & mask1) << lsb) | (d & mask2) > + > + Pattern 3: > + mask1 = (1 << width) - 1 > + d = ((n & mask1) << lsb) | d Is this right? Say that d = 0x42424242 Say that mask1 = 0xFF Say that mask2 = 0xFF00FFFF Say that lsb = 16 Say that n = 0xBC Note that 0x42 | 0xBC = 0xFE With pattern 2, we will get: ((0xBC & 0xFF) << 16) | (0x42424242 & 0xFF00FFFF) = 0xBC0000 | 0x42004242 = 0x42BC4242 With pattern 3, we will get: ((0xBC & 0xFF) << 16) | 0x42424242 = 0xBC0000 | 0x42424242 = 0x42FE4242 I don't think they're equivalent patterns.

Yijia Huang

Comment 3 2021-06-24 10:20:12 PDT

Created attachment 432184 [details] Patch

Yijia Huang

Comment 4 2021-06-24 10:29:30 PDT

Created attachment 432185 [details] Patch

Yijia Huang

Comment 5 2021-06-24 10:47:17 PDT

(In reply to Filip Pizlo from comment #2) > Comment on attachment 432140 [details] > Patch > > View in context: > https://bugs.webkit.org/attachment.cgi?id=432140&action=review > > > Source/JavaScriptCore/ChangeLog:28 > > + Pattern 2: > > + mask1 = (1 << width) - 1 > > + mask2 = ~(mask1 << lsb) > > + d = ((n & mask1) << lsb) | (d & mask2) > > + > > + Pattern 3: > > + mask1 = (1 << width) - 1 > > + d = ((n & mask1) << lsb) | d > > Is this right? > > Say that d = 0x42424242 > Say that mask1 = 0xFF > Say that mask2 = 0xFF00FFFF > Say that lsb = 16 > Say that n = 0xBC > > Note that 0x42 | 0xBC = 0xFE > > With pattern 2, we will get: > > ((0xBC & 0xFF) << 16) | (0x42424242 & 0xFF00FFFF) > = 0xBC0000 | 0x42004242 > = 0x42BC4242 > > With pattern 3, we will get: > > ((0xBC & 0xFF) << 16) | 0x42424242 > = 0xBC0000 | 0x42424242 > = 0x42FE4242 > > I don't think they're equivalent patterns. Thanks. I have fixed that.

Yijia Huang

Comment 6 2021-06-24 13:31:16 PDT

Created attachment 432205 [details] Patch

EWS

Comment 7 2021-06-24 15:50:26 PDT

Committed r279249 (239133@main): <https://commits.webkit.org/239133@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 432205 [details].

Yusuke Suzuki

Comment 8 2021-06-24 16:47:48 PDT

Committed r279253 (239137@main): <https://commits.webkit.org/239137@main>

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