Re: GNAT parameter passing, C-style?

[Hyman Rosen <hyrosen@mail.com>]

Frank J. Lhota wrote:
> I go back to my original question: does anyone know of a C compiler which,
> when compiling C (not C++) does not default to the C calling convention
> (i.e. arguments pushed on the stack in reverse order, and popped off by
> calling function) in the absence of any indication of another convention?

Certainly. Here's partial output of such code compiled on a Sun
with the simple invocation 'cc -S g.c'. As you can see, arguments
are passed in registers and processed left-to-right.

main:
     save    %sp,-104,%sp
.L15:
! File g.c:
!    1  extern int f();
!    2  int main()
!    3  {
!    4      return f(1, 2.0, 3, 4.0);
     mov 1,%o0
     sethi   %hi(.L_cseg0),%l0
     or  %l0,%lo(.L_cseg0),%l0
     ldd [%l0+0],%f2
     mov 3,%o3
     ldd [%l0+8],%f4
     std %f2,[%sp+88]
     ld  [%sp+88],%o1
     ld  [%sp+92],%o2
     std %f4,[%sp+88]
     call    f
     ldd [%sp+88],%o4
     ba  .L14
     mov %o0,%l0

     ! block 2
.L14:
     mov %l0,%i0
     jmp %i7+8
     restore