On Wed, Aug 19, 2015 at 3:10 PM, Segher Boessenkool
<seg...@kernel.crashing.org> wrote:
> On Wed, Aug 19, 2015 at 02:53:47PM -0700, H.J. Lu wrote:
>> How about this
>>
>> @deftypefn {Built-in Function} {void *} __builtin_argument_pointer (void)
>> This function is similar to @code{__builtin_frame_address} with an
>> argument of 0, but it returns the address of the incoming arguments to
>> the current function rather than the address of its frame. Unlike
>> @code{__builtin_frame_address}, the frame pointer register isn't
>> required.
>
> That last line isn't true, if your port uses INITIAL_FRAME_POINTER_RTX.
> Maybe it shouldn't be true otherwise either (but currently a hard frame
> pointer is forced, indeed). Have we gone full circle now? ;-)
Let's drop it:
@deftypefn {Built-in Function} {void *} __builtin_argument_pointer (void)
This function is similar to @code{__builtin_frame_address} with an
argument of 0, but it returns the address of the incoming arguments to
the current function rather than the address of its frame.
The exact definition of this address depends upon the processor and the
calling convention. Usually some arguments are passed in registers and
the rest on the stack, and this builtin returns the address of the
first argument which would be passed on the stack.
@end deftypefn
--
H.J.
