http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47419
--- Comment #1 from Pawel Sikora <pluto at agmk dot net> 2011-01-23 09:36:57
UTC ---
(In reply to comment #0)
> following code...
>
> unsigned __attribute__((regparm(2)))
> asm_read_mapped_register( unsigned* address, unsigned long index )
> {
> unsigned value;
> asm /* reading has side-effects in hardware */ volatile (
> "movl (%1), %0"
> : /* output operands */ "=r" ( value )
> : /* input operands */ "r" ( address + index )
btw. ^^^ changing "r" to "g" doesn't help.
> : /* clobbers */
> );
> return value;
> }
>
> produces...
>
> asm_read_mapped_register:
> leaq (%rdi,%rsi,4), %rax
> movl (%rax), %eax
> ret
>
> is it a bug in asm inline? why the 'movl (%rdi,%rsi,4),%eax' isn't emitted?
