Are pretend arguments included in the outgoing argument region ?

[Segher Boessenkool]

On Tue, Aug 13, 2019 at 10:32:27PM -0500, William Tambe wrote:
> On Tue, Aug 13, 2019 at 9:44 PM Jeff Law <law@redhat.com> wrote:
> >
> > On 8/13/19 7:41 PM, William Tambe wrote:
> > > Are pretend arguments included in the outgoing argument region ?
> > > In other words, when ACCUMULATE_OUTGOING_ARGS is nonzero, does
> > > crtl->outgoing_args_size include crtl->args.pretend_args_size ?
> > >
> > I think it varies depending on the target's ABI.
> > OUTGOING_REG_PARM_STACK_SPACE, STACK_PARMS_IN_REG_PARM_AREA,
> > REG_PARM_STACK_SPACE, etc likely come into play here.
> >
> > It may be better for you to describe the ABI you're working with.
> > There's a reasonable chance it'll line up with an existing port's ABI
> > and you can crib from that existing port.  Make sure to describe how
> > varargs/stdarg is supposed to work, whether or not you have arguments
> > passed partially in registers and partially in memory,
> 
> The ABI I am working with pass arguments through registers where
> NUM_ARG_REGS is the number of registers used to pass arguments.
> 
> Given the following #define, is it enough to assume that pretend
> arguments will be included in the outgoing argument region and that
> crtl->outgoing_args_size will include crtl->args.pretend_args_size ?
> 
> #define ACCUMULATE_OUTGOING_ARGS 1
> #define REG_PARM_STACK_SPACE(F) (NUM_ARG_REGS*UNITS_PER_WORD)
> #define OUTGOING_REG_PARM_STACK_SPACE(FNTYPE) 1
> #define STACK_PARMS_IN_REG_PARM_AREA

Given your description, should you define any of the REG_PARM macros
at all?  *Is* there an "outgoing argument region" in your ABI, if all
args are passed in registers?


Segher