specifier on operand in asm inline

[Ian Lance Taylor]

dofg <dofg@ya.ru> writes:

> you gave the description of the constraints
> : "=&r" ((USItype)(r1)),
>   "=&r" ((USItype)(r0))
> : "%rJ" ((USItype)(x3)),
>   "rI" ((USItype)(y3)),
> i am pointing to
> "subx %r2,%3,%%g1\n\t"
> more definitely, to %r2. operand of subx. 'r' here is also a
> constraint, telling compiler to use register?

Oh, sorry.  That's not a constraint.  That's an operand modifier.

For SPARC %r2 means that if the argument is the integer zero, it
should print %g0.  Otherwise it should print the operand as usual.

Ian