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Re: [PATCH 4/4] x86: Add 'V' register operand modifier
On Fri, Jan 12, 2018 at 10:00 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>> Add 'V', a special modifier which prints the name of the full integer
>> register without '%'. For
>>
>> extern void (*func_p) (void);
>>
>> void
>> foo (void)
>> {
>> asm ("call __x86_indirect_thunk_%V0" : : "a" (func_p));
>> }
>>
>> it generates:
>>
>> foo:
>> movq func_p(%rip), %rax
>> call __x86_indirect_thunk_rax
>> ret
>>
>> gcc/
>>
>> * config/i386/i386.c (print_reg): Print the name of the full
>> integer register without '%'.
>> (ix86_print_operand): Handle 'V'.
>> * doc/extend.texi: Document 'V' modifier.
>
> Seems reasonable. Purpose of this is to make posible to call thunks
> from asm statements, right?
>
Yes.
--
H.J.