parmreg.c

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C语言 代码 · 共 90 行

/****************************************************************************
*
*                            Open Watcom Project
*
*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
*  ========================================================================
*
*    This file contains Original Code and/or Modifications of Original
*    Code as defined in and that are subject to the Sybase Open Watcom
*    Public License version 1.0 (the 'License'). You may not use this file
*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
*    ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
*    provided with the Original Code and Modifications, and is also
*    available at www.sybase.com/developer/opensource.
*
*    The Original Code and all software distributed under the License are
*    distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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*    NON-INFRINGEMENT. Please see the License for the specific language
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*  ========================================================================
*
* Description:  WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE
*               DESCRIBE IT HERE!
*
****************************************************************************/


#include "standard.h"
#include "coderep.h"
#include "opcodes.h"
#include "sysmacro.h"
#include "procdef.h"
#include "cgdefs.h"
#include "typedef.h"
#include "regset.h"
#include "zoiks.h"
#include "feprotos.h"

extern  hw_reg_set      InLineParm(hw_reg_set,hw_reg_set);
extern  reg_list        *ParmChoices(type_class_def);
extern  type_def        *TypeAddress(cg_type);
extern  hw_reg_set      ParmRegConflicts(hw_reg_set);

extern  type_length     ParmAlignment( type_def *tipe ) {
/*******************************************************/

    tipe = tipe;
    return( 1 );
}

extern  hw_reg_set      ParmReg( type_class_def class, type_length len, type_length alignment, call_state *state ) {
/******************************************************************************************************************/

    hw_reg_set  *possible;
    hw_reg_set  *reg_set;
    hw_reg_set  regs;

    len = len;
    alignment = alignment;
    possible = ParmChoices( class );
    if( possible == NULL || HW_CEqual( *possible, HW_EMPTY ) ) {
        if( !HW_CEqual( *state->parm.curr_entry, HW_EMPTY ) ) {
            state->parm.curr_entry++;
        }
        return( HW_EMPTY );
    }
    while( !HW_CEqual( *state->parm.curr_entry, HW_EMPTY ) ) {
        reg_set = possible;
        for(;;) {
            regs = *reg_set;
            if( HW_CEqual( regs, HW_EMPTY ) ) break;
            if( !HW_Ovlap( regs, state->parm.used ) ) {
                if( HW_Subset( *state->parm.curr_entry, regs ) ) {
                    HW_TurnOn( state->parm.used, regs );
                    HW_TurnOn( state->parm.used, ParmRegConflicts( regs ) );
                    return( regs );
                }
            }
            ++ reg_set;
        }
        state->parm.curr_entry ++;
    }
    return( HW_EMPTY );
}