Bug 171118 - X86-64 assembler doesn't handle xchg with byte register src
Summary: X86-64 assembler doesn't handle xchg with byte register src
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: Other
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Michael Saboff
Keywords: InRadar
Depends on:
Reported: 2017-04-21 10:29 PDT by Michael Saboff
Modified: 2017-04-21 11:28 PDT (History)
6 users (show)

See Also:

Patch (1.51 KB, patch)
2017-04-21 10:38 PDT, Michael Saboff
sbarati: review+
Details | Formatted Diff | Diff

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Description Michael Saboff 2017-04-21 10:29:50 PDT
The Intel manual Vol 2A 3-3 shows that byte registers SPL and greater require a REX prefix byte.  The is done with the X86Assembler function oneByteOp8().  Use of that function was omitted when the xchg8_*() functions was added.
Comment 1 Radar WebKit Bug Importer 2017-04-21 10:32:14 PDT
Comment 2 Michael Saboff 2017-04-21 10:38:51 PDT
Created attachment 307746 [details]

I did verify that all other byte ops use the *Op8() formatter function.
Comment 3 Michael Saboff 2017-04-21 10:42:33 PDT
I fixed the spelling in the bug title, including the ChangeLog.
Comment 4 Michael Saboff 2017-04-21 11:28:53 PDT
Committed r215618: <http://trac.webkit.org/changeset/215618>