/*

 Package: dyncall
 Library: dyncallback
 File: dyncallback/dyncall_args_mips.c
 Description: Callback's Arguments VM - Implementation for MIPS
 License:

   Copyright (c) 2013-2015 Daniel Adler <dadler@uni-goettingen.de>,
                           Tassilo Philipp <tphilipp@potion-studios.com>

   Permission to use, copy, modify, and distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

*/


#include "dyncall_args_mips.h"

DCint dcbArgInt(DCArgs* p)
{
  DCint value;
  p->freg_count = 2; // first int will disable float reg use.
  value = *((int*)p->stackptr);
  p->stackptr += sizeof(int);
  return value;
}
DCuint dcbArgUInt(DCArgs* p) { return (DCuint)dcbArgInt(p); }

DCulonglong dcbArgULongLong(DCArgs* p)
{
  DCulonglong value;
  p->stackptr += ((int)p->stackptr & 4); // Skip one slot if not aligned.
#if defined(DC__Endian_LITTLE)
  value  = dcbArgUInt(p);
  value |= ((DCulonglong)dcbArgUInt(p)) << 32;
#else
  value  = ((DCulonglong)dcbArgUInt(p)) << 32;
  value |= dcbArgUInt(p);
#endif
  return value;
}
DClonglong dcbArgLongLong(DCArgs* p) { return (DClonglong)dcbArgULongLong(p); }

DClong      dcbArgLong   (DCArgs* p) { return (DClong)   dcbArgUInt(p); }
DCulong     dcbArgULong  (DCArgs* p) { return (DCulong)  dcbArgUInt(p); }
DCchar      dcbArgChar   (DCArgs* p) { return (DCchar)   dcbArgUInt(p); }
DCuchar     dcbArgUChar  (DCArgs* p) { return (DCuchar)  dcbArgUInt(p); }
DCshort     dcbArgShort  (DCArgs* p) { return (DCshort)  dcbArgUInt(p); }
DCushort    dcbArgUShort (DCArgs* p) { return (DCushort) dcbArgUInt(p); }
DCbool      dcbArgBool   (DCArgs* p) { return (DCbool)   dcbArgUInt(p); }
DCpointer   dcbArgPointer(DCArgs* p) { return (DCpointer)dcbArgUInt(p); }

DCfloat dcbArgFloat(DCArgs* p)
{
  DCfloat result;
  if(p->freg_count < 2) {
	// Stored float regs (max 2) are always 8b aligned. The way we look them up,
	// relative to a diverging p->stackptr, we need consider this. Only works
	// with up to two float args, which is all we need. Hacky, but saves us
	// from one more variable and more bookkeeping in DCArgs.
    result = ((DCfloat*)(p->stackptr + ((int)p->stackptr & 4)) - 4) // '-4' b/c those regs are stored right before the args
#if defined(DC__Endian_LITTLE)
      [0];
#else
      [1];
#endif
	++p->freg_count;
  } else {
    result = *((DCfloat*)p->stackptr);
  }
  p->stackptr += sizeof(DCfloat);
  return result;
}
DCdouble dcbArgDouble(DCArgs* p)
{
  union {
    DCdouble result;
    DCfloat f[2];
  } d;
  p->stackptr += ((int)p->stackptr & 4); // Skip one slot if not aligned.
  if(p->freg_count < 2) {
    //result = *((DCdouble*)p->stackptr-2); this changes the value, slightly
    d.f[0] = ((DCfloat*)p->stackptr-4)[0]; // '-4' b/c those regs are stored right before the args
    d.f[1] = ((DCfloat*)p->stackptr-4)[1];
    ++p->freg_count;
  } else {
    //result = *((DCdouble*)p->stackptr); this changes the value, slightly
    d.f[0] = ((DCfloat*)p->stackptr)[0];
    d.f[1] = ((DCfloat*)p->stackptr)[1];
  }
  p->stackptr += sizeof(DCdouble);
  return d.result;
}