/* src/vm/jit/x86_64/md-abi.c - functions for x86_64 Linux ABI

   Copyright (C) 1996-2005, 2006 R. Grafl, A. Krall, C. Kruegel,
   C. Oates, R. Obermaisser, M. Platter, M. Probst, S. Ring,
   E. Steiner, C. Thalinger, D. Thuernbeck, P. Tomsich, C. Ullrich,
   J. Wenninger, Institut f. Computersprachen - TU Wien

   This file is part of CACAO.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.

   Contact: cacao@cacaojvm.org

   Authors: Christian Thalinger

   Changes:

   $Id: md-abi.c 4488 2006-02-12 12:59:52Z christian $

*/


#include "config.h"
#include "vm/types.h"

#include "vm/jit/x86_64/md-abi.h"

#include "vm/descriptor.h"
#include "vm/global.h"


/* register descripton array **************************************************/

s4 nregdescint[] = {
    REG_RET, REG_ARG, REG_ARG, REG_TMP, REG_RES, REG_SAV, REG_ARG, REG_ARG,
    REG_ARG, REG_ARG, REG_RES, REG_RES, REG_SAV, REG_SAV, REG_SAV, REG_SAV,
    REG_END
};


s4 nregdescfloat[] = {
    REG_ARG, REG_ARG, REG_ARG, REG_ARG, REG_ARG, REG_ARG, REG_ARG, REG_ARG,
    REG_RES, REG_RES, REG_RES, REG_TMP, REG_TMP, REG_TMP, REG_TMP, REG_TMP,
    REG_END
};


/* md_param_alloc **************************************************************

   XXX

*******************************************************************************/

void md_param_alloc(methoddesc *md)
{
	paramdesc *pd;
	s4         i;
	s4         iarg;
	s4         farg;
	s4         stacksize;

	/* set default values */

	iarg = 0;
	farg = 0;
	stacksize = 0;

	/* get params field of methoddesc */

	pd = md->params;

	for (i = 0; i < md->paramcount; i++, pd++) {
		switch (md->paramtypes[i].type) {
		case TYPE_INT:
		case TYPE_ADR:
		case TYPE_LNG:
			if (iarg < INT_ARG_CNT) {
				pd->inmemory = false;
				pd->regoff = iarg;
			} else {
				pd->inmemory = true;
				pd->regoff = stacksize;
			}
			if (iarg < INT_ARG_CNT)
				iarg++;
			else
				stacksize++;
			break;
		case TYPE_FLT:
		case TYPE_DBL:
			if (farg < FLT_ARG_CNT) {
				pd->inmemory = false;
				pd->regoff = farg;
			} else {
				pd->inmemory = true;
				pd->regoff = stacksize;
			}
			if (farg < FLT_ARG_CNT)
				farg++;
			else
				stacksize++;
			break;
		}
	}

	/* Since XMM0 (==A0) is used for passing return values, this */
	/* argument register usage has to be regarded, too           */
	if (IS_FLT_DBL_TYPE(md->returntype.type))
		if (farg < 1)
			farg = 1;

	/* fill register and stack usage */

	md->argintreguse = iarg;
	md->argfltreguse = farg;
	md->memuse = stacksize;
}


/* md_return_alloc *************************************************************

   Precolor the Java Stackelement containing the Return Value. Only
   for float/ double types straight forward possible, since INT_LNG
   types use "reserved" registers Float/Double values use a00 as
   return register.

   --- in
   m:                       Methodinfo of current method
   return_type:             Return Type of the Method (TYPE_INT.. TYPE_ADR)
   							TYPE_VOID is not allowed!
   stackslot:               Java Stackslot to contain the Return Value

   --- out
   if precoloring was possible:
   stackslot->varkind       =ARGVAR
   			->varnum        =-1
   			->flags         =0
   			->regoff        =[REG_RESULT, (REG_RESULT2/REG_RESULT), REG_FRESULT]
   rd->arg[flt|int]reguse   set to a value according the register usage

*******************************************************************************/

void md_return_alloc(methodinfo *m, registerdata *rd, s4 return_type,
					 stackptr stackslot)
{
	/* precoloring only straightforward possible with flt/dbl types
	   For Address/Integer/Long REG_RESULT == rax == REG_ITMP1 and so
	   could be destroyed if the return value Stack Slot "lives too
	   long" */

	if (IS_FLT_DBL_TYPE(return_type)) {
		/* In Leafmethods Local Vars holding parameters are precolored
		   to their argument register -> so leafmethods with
		   paramcount > 0 could already use a00! */

		if (!m->isleafmethod || (m->parseddesc->paramcount == 0)) {
			/* Only precolor the stackslot, if it is not a SAVEDVAR
			   <-> has not to survive method invokations */

			if (!(stackslot->flags & SAVEDVAR)) {
				stackslot->varkind = ARGVAR;
				stackslot->varnum = -1;
				stackslot->flags = 0;

			    /* float/double */
				if (rd->argfltreguse < 1)
					rd->argfltreguse = 1;

				stackslot->regoff = REG_FRESULT;
			}
		}
	}
}


/*
 * These are local overrides for various environment variables in Emacs.
 * Please do not remove this and leave it at the end of the file, where
 * Emacs will automagically detect them.
 * ---------------------------------------------------------------------
 * Local variables:
 * mode: c
 * indent-tabs-mode: t
 * c-basic-offset: 4
 * tab-width: 4
 * End:
 */