Ian Lance Taylor writes:
> "Bryce Schober" <bryce.schober@xxxxxxxxxxxxxxxxx> writes:
>
> > So how should I go about wrapping ldm / stm for usage in C land?
> >
> > I tried:
> >
> > typedef struct
> > {
> > UNS_32 reg[2];
> > } arm_2_registers_t;
> >
> > static inline
> > arm_2_registers_t arm_2_registers_load(
> > UNS_32 *src_addr_ptr )
> > {
> > arm_2_registers_t result;
> > __asm__ (
> > "ldmia %0, {%1,%2} \n\t"
> > : "+r" (src_addr_ptr), "=r" (result.reg[0]), "=r" (result.reg[1])
> > );
> > return( result );
> > }
> >
> > That seems to work fine until the compiler decides to use registers
> > for %1 and %2 that aren't in ascending order. I've examined the
> > assembly constraints and I don't see anything obvious.
>
> There is in general no way to do that.
Sure, but there's nothing to stop him picking two named register
variables.
Andrew.
