On 4/10/07, Andrew Haley <aph@xxxxxxxxxxx> wrote:
Sure, but there's nothing to stop him picking two named register
variables.
Following Andrew's hint, the following works:
typedef struct
{
int reg[2];
} arm_2_registers_t;
static inline
arm_2_registers_t arm_2_registers_load(
int *src_addr_ptr )
{
register int result_0 __asm__ ("r3");
register int result_1 __asm__ ("r4");
arm_2_registers_t result;
__asm__ __volatile__ (
"ldmia %0, {%1,%2} \n\t"
: "+r" (src_addr_ptr), "=r" (result_0), "=r" (result_1)
);
result.reg[0] = result_0;
result.reg[1] = result_1;
return( result );
}
It's still pretty sub-optimal, though, since the registers have to be
specified, which could lead to a bunch of register-to-register moving
when using several functions like this. It'd be a bit better as a
macro that could take the register names as arguments.
It's too bad that the assembler can't just make the right choice for
us... It doesn't seem like *that* hard a problem...
--
Bryce Schober
