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| author | H.J. Lu <hjl.tools@gmail.com> | 2018-02-22 06:18:27 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2018-02-22 06:18:39 -0800 |
| commit | 6b6b680700699c15e22b6c36975729035676eef1 (patch) | |
| tree | 436eba8cc606c8539c1185c14d74efb96b43a841 /gas/doc | |
| parent | 39334a61e63321352304cbae77b37fcba4fed662 (diff) | |
| download | gdb-6b6b680700699c15e22b6c36975729035676eef1.zip gdb-6b6b680700699c15e22b6c36975729035676eef1.tar.gz gdb-6b6b680700699c15e22b6c36975729035676eef1.tar.bz2 | |
x86: Add {rex} pseudo prefix
Add {rex} pseudo prefix to generate a REX byte for integer and legacy
vector instructions if possible. Note that this differs from the rex
prefix which generates REX prefix unconditionally.
gas/
* config/tc-i386.c (_i386_insn): Add rex_encoding.
(md_assemble): When i.rex_encoding is true, generate a REX byte
if possible.
(parse_insn): Set i.rex_encoding for {rex}.
* doc/c-i386.texi: Document {rex}.
* testsuite/gas/i386/x86-64-pseudos.s: Add {rex} tests.
* testsuite/gas/i386/x86-64-pseudos.d: Updated.
opcodes/
* i386-opc.tbl: Add {rex},
* i386-tbl.h: Regenerated.
Diffstat (limited to 'gas/doc')
| -rw-r--r-- | gas/doc/c-i386.texi | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/gas/doc/c-i386.texi b/gas/doc/c-i386.texi index e669c5f..6b2def0 100644 --- a/gas/doc/c-i386.texi +++ b/gas/doc/c-i386.texi @@ -642,6 +642,11 @@ Different encoding options can be specified via pseudo prefixes: @item @samp{@{evex@}} -- encode with EVEX prefix. + +@item +@samp{@{rex@}} -- prefer REX prefix for integer and legacy vector +instructions (x86-64 only). Note that this differs from the @samp{rex} +prefix which generates REX prefix unconditionally. @end itemize @cindex conversion instructions, i386 |