[PATCH 02/10] x86: drop stray W
Wed Aug 7 15:14:00 GMT 2019
On Wed, Aug 7, 2019 at 12:43 AM Jan Beulich <firstname.lastname@example.org> wrote:
> On 06.08.2019 21:37, H.J. Lu wrote:
> > On Tue, Aug 6, 2019 at 7:25 AM Jan Beulich <email@example.com> wrote:
> >> The flag is used to indicate opcodes which can be switched between byte
> >> and word/dword/qword forms (in a "canonical" way). Obviously it's quite
> >> odd then to see it on insns not allowing for byte operands in the first
> >> place. As a result the opcode bytes need to be adjusted accordingly,
> >> which includes comparisons done in optimize_encoding().
> > These encodings do allow byte operand.
> By "encodings" I assume you mean the opcodes, not the templates. The
> templates modified here all clearly don't allow byte operands, and
> that's what counts when considering whether W is applicable.
i.tm.opcode_modifier.w is checked only in process_suffix. This part
/* It's not a byte, select word/dword operation. */
i.tm.base_opcode |= 8;
i.tm.base_opcode |= 1;
applies to encoding. Even if we can't merge entries in i386-opc.tbl,
W still makes senses. Will keeping W cause any issues?
> > The reason why they are in
> > a separate entry is Cpu64. Can they be merged without Cpu64?
> I don't think they can, let me got through:
More information about the Binutils