/* vacall function for alpha CPU */

/*
 * Copyright 1995 Bruno Haible, <haible@ma2s2.mathematik.uni-karlsruhe.de>
 *
 * This is free software distributed under the GNU General Public Licence
 * described in the file COPYING. Contact the author if you don't have this
 * or can't live with it. There is ABSOLUTELY NO WARRANTY, explicit or implied,
 * on this software.
 */

#include "vacall.h.in"

register long		arg1	__asm__("$16");
register long		arg2	__asm__("$17");
register long		arg3	__asm__("$18");
register long		arg4	__asm__("$19");
register long		arg5	__asm__("$20");
register long		arg6	__asm__("$21");
register double		farg1	__asm__("$f16");
register double		farg2	__asm__("$f17");
register double		farg3	__asm__("$f18");
register double		farg4	__asm__("$f19");
register double		farg5	__asm__("$f20");
register double		farg6	__asm__("$f21");
register __vaword	iret	__asm__("$0");
register __vaword	iret2	__asm__("$1");
register float		fret	__asm__("$f0");
register double		dret	__asm__("$f0");

void /* the return type is variable, not void! */
vacall (__vaword word1, __vaword word2, __vaword word3, __vaword word4,
        __vaword word5, __vaword word6,
        __vaword firstword)
{
  __va_alist list;
  struct { double farg1, farg2, farg3, farg4, farg5, farg6;
           long arg1, arg2, arg3, arg4, arg5, arg6;
         }
    args;
  /* MAGIC ALERT! This is the last struct on the stack, so that
   * &args + 1 == &firstword. Look at the assembly code to convince yourself.
   */
  /* Move the arguments passed in registers to their stack locations. */
  /* args.arg1 = */ (&firstword)[-6] = word1;
  /* args.arg2 = */ (&firstword)[-5] = word2;
  /* args.arg3 = */ (&firstword)[-4] = word3;
  /* args.arg4 = */ (&firstword)[-3] = word4;
  /* args.arg5 = */ (&firstword)[-2] = word5;
  /* args.arg6 = */ (&firstword)[-1] = word6;
  args.farg1 = farg1;
  args.farg2 = farg2;
  args.farg3 = farg3;
  args.farg4 = farg4;
  args.farg5 = farg5;
  args.farg6 = farg6;
  /* Prepare the va_alist. */
  list.flags = 0;
  list.aptr = (long)(&firstword - 6);
  list.raddr = (void*)0;
  list.rtype = __VAvoid;
  list.memargptr = (long)&firstword;
  /* Call vacall_function. The macros do all the rest. */
  (*vacall_function) (&list);
  /* Put return value into proper register. */
  switch (list.rtype)
    {
      case __VAvoid:	break;
      case __VAchar:	iret = list.tmp._char; break;
      case __VAschar:	iret = list.tmp._schar; break;
      case __VAuchar:	iret = list.tmp._uchar; break;
      case __VAshort:	iret = list.tmp._short; break;
      case __VAushort:	iret = list.tmp._ushort; break;
      case __VAint:	iret = list.tmp._int; break;
      case __VAuint:	iret = list.tmp._uint; break;
      case __VAlong:	iret = list.tmp._long; break;
      case __VAulong:	iret = list.tmp._ulong; break;
      case __VAfloat:	fret = list.tmp._float; break;
      case __VAdouble:	dret = list.tmp._double; break;
      case __VAvoidp:	iret = (long)list.tmp._ptr; break;
      case __VAstruct:
        if (list.flags & __VA_PCC_STRUCT_RETURN)
          { /* pcc struct return convention */
            iret = (long) list.raddr;
          }
        else
          { /* normal struct return convention */
            if (list.flags & __VA_REGISTER_STRUCT_RETURN)
              switch (list.rsize)
                { case sizeof(char):  iret = *(unsigned char *) list.raddr; break;
                  case sizeof(short): iret = *(unsigned short *) list.raddr; break;
                  case sizeof(int):   iret = *(unsigned int *) list.raddr; break;
                  case sizeof(long):  iret = *(unsigned long *) list.raddr; break;
                  case 2*sizeof(__vaword):
                    iret  = ((__vaword *) list.raddr)[0];
                    iret2 = ((__vaword *) list.raddr)[1];
                    break;
                  default:            break;
                }
          }
        break;
    }
}