source: mainline/uspace/app/pcc/arch/pdp10/order.c@ 814717fa

/*      $Id: order.c,v 1.63 2008/01/15 21:47:06 ragge Exp $     */
/*
 * Copyright (c) 2003 Anders Magnusson (ragge@ludd.luth.se).
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


# include "pass2.h"

int canaddr(NODE *);

/* is it legal to make an OREG or NAME entry which has an
 * offset of off, (from a register of r), if the
 * resulting thing had type t */
int
notoff(TWORD t, int r, CONSZ off, char *cp)
{
        return(0);  /* YES */
}

int radebug = 0;

void
offstar(NODE *p, int shape)
{
        NODE *q;

        if (x2debug)
                printf("offstar(%p)\n", p);

        if( p->n_op == PLUS || p->n_op == MINUS ){
                if( p->n_right->n_op == ICON ){
                        q = p->n_left;
                        if (q->n_op != REG)
                                geninsn(q, INAREG);
                        p->n_su = -1;
                }
        }
        geninsn(p, INAREG);
}

/*
 * findops() failed, see if we can rewrite it to match.
 */
int
setbin(NODE *p)
{
        TWORD ty;
        NODE *r, *s;

        ty = p->n_type;
        switch (p->n_op) {
        case MINUS:
                switch (ty) {
                case PTR+CHAR:
                case PTR+UCHAR:
                case PTR+SHORT:
                case PTR+USHORT:
                        /*
                         * Must negate the right side and change op to PLUS.
                         */
                        r = p->n_right;
                        if (r->n_op == ICON) {
                                r->n_lval = -r->n_lval;
                        } else {
                                s = talloc();
                                s->n_type = r->n_type;
                                s->n_op = UMINUS;
                                s->n_left = r;
                                p->n_right = s;
                        }
                        p->n_op = PLUS;
                        return 1;
                }
        }
        return 0;
}

/* setup for assignment operator */
int
setasg(NODE *p, int cookie)
{
        return(0);
}

/* setup for unary operator */
int
setuni(NODE *p, int cookie)
{
        return 0;
}

int
special(NODE *p, int shape)
{
        switch (shape) {
        case SUSHCON:
                if (p->n_op == ICON && p->n_name[0] == '\0' &&
                    (p->n_lval > 0 && p->n_lval <= 0777777))
                        return 1;
                break;

        case SNSHCON:
                if (p->n_op == ICON && p->n_name[0] == '\0' &&
                    (p->n_lval < 0 && p->n_lval > -01000000))
                        return 1;
                break;
        case SILDB:
                if (p->n_op == ASSIGN && p->n_left->n_op == REG &&
                    p->n_right->n_op == PLUS &&
                    p->n_right->n_left->n_op == REG &&
                    p->n_right->n_right->n_op == ICON && 
                    p->n_right->n_right->n_lval == 1 &&
                    p->n_right->n_left->n_rval == p->n_left->n_rval)
                        return 1;
                break;
        }
        return 0;
}

/*
 * Set evaluation order of a binary node if it differs from default.
 */
int
setorder(NODE *p)
{
        return 0; /* nothing differs on x86 */
}

/*
 * Special handling of some instruction register allocation.
 */
struct rspecial *
nspecial(struct optab *q)
{
        return 0; /* XXX gcc */
}

/*
 * Do the actual conversion of offstar-found OREGs into real OREGs.
 */
void
myormake(NODE *p)
{
        if (x2debug)
                printf("myormake(%p)\n", p);
}

/*
 * set registers in calling conventions live.
 */
int *
livecall(NODE *p)
{
        static int r[8], *s = r;

        *s = -1;
        if (p->n_op == UCALL || p->n_op == UFORTCALL || p->n_op == USTCALL ||
            p->n_op == FORTCALL)
                return s;
        for (p = p->n_right; p->n_op == CM; p = p->n_left) {
                if (p->n_right->n_op == ASSIGN &&
                    p->n_right->n_left->n_op == REG)
                        *s++ = p->n_right->n_left->n_rval;
        }
        if (p->n_op == ASSIGN &&
            p->n_left->n_op == REG)
                *s++ = p->n_left->n_rval;
        *s = -1;
        return r;
}

/*
 * Signal whether the instruction is acceptable for this target.
 */
int
acceptable(struct optab *op)
{
        return 1;
}