Bug 203752

Summary:

The offline assembler is wrong about which immediates are supported by and/or/xor on ARM64

Product:

WebKit

Reporter:

Robin Morisset <rmorisset>

Component:

JavaScriptCore

Assignee:

Robin Morisset <rmorisset>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

commit-queue, 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:

Bug Blocks:

Attachments:

Robin Morisset

Reported 2019-11-01 13:04:08 PDT

It uses the same list of valid immediates for and/or/xor as for add/sub/mul but it is much more subtle, see: https://dinfuehr.github.io/blog/encoding-of-immediate-values-on-aarch64/. This is fine for now by chance, but changing the layout of ArithProfile can cause us to emit invalid constants in the generated assembly (this is blocking https://bugs.webkit.org/show_bug.cgi?id=202832).

Attachments
Patch (5.36 KB, patch) 2019-11-01 13:40 PDT, Robin Morisset	no flags	Details Formatted Diff Diff
Patch (5.36 KB, patch) 2019-11-01 13:46 PDT, Robin Morisset	no flags	Details Formatted Diff Diff
Patch (5.56 KB, patch) 2019-11-01 14:05 PDT, Robin Morisset	no flags	Details Formatted Diff Diff
Show Obsolete (2) View All Add attachment proposed patch, testcase, etc.