Logo Search packages:      
Sourcecode: pcc version File versions  Download package

order.c

/*      $Id: order.c,v 1.9 2008/09/27 07:35:22 ragge Exp $    */
/*
 * Copyright (c) 2007 Gregory McGarry (g.mcgarry@ieee.org).
 * 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.
 */

/*
 *  Machine-dependent code-generation strategy (pass 2).
 */

#include <assert.h>
#include <string.h>

#include "pass2.h"

/*
 * Check size of offset in OREG.  Called by oregok() to see if an
 * OREG can be generated.
 */
int
notoff(TWORD ty, int r, CONSZ off, char *cp)
{
      if (cp && cp[0]) return 1;
      if (DEUNSIGN(ty) == INT || ty == UCHAR)
            return !(off < 4096 && off > -4096);
      else
            return !(off < 256 && off > -256);
}

/*
 * Generate instructions for an OREG.  Why is this routine MD?
 * Called by swmatch().
 */
void
offstar(NODE *p, int shape)
{
      NODE *r;

      if (isreg(p))
            return; /* Is already OREG */

      r = p->n_right;
      if( p->n_op == PLUS || p->n_op == MINUS ){
            if( r->n_op == ICON ){
                  if (isreg(p->n_left) == 0)
                        (void)geninsn(p->n_left, INAREG);
                  /* Converted in ormake() */
                  return;
            }
            /* usually for arraying indexing: */
            if (r->n_op == LS && r->n_right->n_op == ICON &&
                r->n_right->n_lval == 2 && p->n_op == PLUS) {
                  if (isreg(p->n_left) == 0)
                        (void)geninsn(p->n_left, INAREG);
                  if (isreg(r->n_left) == 0)
                        (void)geninsn(r->n_left, INAREG);
                  return;
            }
      }
      (void)geninsn(p, INAREG);
}

/*
 * Unable to convert to OREG (notoff() returned failure).  Output
 * suitable instructions to replace OREG.
 */
void
myormake(NODE *q)
{
        NODE *p, *r;

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

      p = q->n_left;

      /*
       * This handles failed OREGs conversions, due to the offset
       * being too large for an OREG.
       */
      if ((p->n_op == PLUS || p->n_op == MINUS) && p->n_right->n_op == ICON) {
            if (isreg(p->n_left) == 0)
                  (void)geninsn(p->n_left, INAREG);
            if (isreg(p->n_right) == 0)
                  (void)geninsn(p->n_right, INAREG);
            (void)geninsn(p, INAREG);
      } else if (p->n_op == REG) {
            q->n_op = OREG;
            q->n_lval = p->n_lval;
            q->n_rval = p->n_rval;
            tfree(p);
      } else if (p->n_op == PLUS && (r = p->n_right)->n_op == LS &&
          r->n_right->n_op == ICON && r->n_right->n_lval == 2 &&
          p->n_left->n_op == REG && r->n_left->n_op == REG) {
            q->n_op = OREG;
            q->n_lval = 0;
            q->n_rval = R2PACK(p->n_left->n_rval, r->n_left->n_rval,
                           r->n_right->n_lval);
            tfree(p);
      }
}

/*
 * Check to if the UMUL node can be converted into an OREG.
 */
int
shumul(NODE *p, int shape)
{
      /* Turns currently anything into OREG */
      if (shape & SOREG)
            return SROREG;
      return SRNOPE;
}

/*
 * Rewrite operations on binary operators (like +, -, etc...).
 * Called as a result of a failed table lookup.
 *
 * Return nonzero to retry table search on new tree, or zero to fail.
 */
int
setbin(NODE *p)
{
      return 0;

}

/*
 * Rewrite assignment operations.
 * Called as a result of a failed table lookup.
 *
 * Return nonzero to retry table search on new tree, or zero to fail.
 */
int
setasg(NODE *p, int cookie)
{
      return 0;
}

/*
 * Rewrite UMUL operation.
 * Called as a result of a failed table lookup.
 *
 * Return nonzero to retry table search on new tree, or zero to fail.
 */
int
setuni(NODE *p, int cookie)
{
      return 0;
}

/*
 * Special handling of some instruction register allocation.
 *
 * Called as a result of specifying NSPECIAL in the table.
 */
struct rspecial *
nspecial(struct optab *q)
{

      switch (q->op) {

#if !defined(ARM_HAS_FPA) && !defined(ARM_HAS_VFP)
      case UMINUS:
      case SCONV:
            if (q->lshape == SBREG && q->rshape == SAREG) {
                  static struct rspecial s[] = {
                        { NLEFT, R0R1 },
                        { NRES, R0 },
                        { 0 }
                  };
                  return s;
            } else if (q->lshape == SAREG && q->rshape == SBREG) {
                  static struct rspecial s[] = {
                        { NLEFT, R0 },
                        { NRES, R0R1 },
                        { 0 }
                  };
                  return s;
            } else if (q->lshape == SAREG && q->rshape == SAREG) {
                  static struct rspecial s[] = {
                        { NLEFT, R0 },
                        { NRES, R0 },
                        { 0 }
                  };
                  return s;
            } else if (q->lshape == SBREG && q->rshape == SBREG) {
                  static struct rspecial s[] = {
                        { NLEFT, R0R1 },
                        { NRES, R0R1 },
                        { 0 }
                  };
                  return s;
            }

      case OPLOG:
            if (q->lshape == SBREG) {
                  static struct rspecial s[] = {
                        { NLEFT, R0R1 },
                        { NRIGHT, R2R3 },
                        { NRES, R0 },
                        { 0 }
                  };
                  return s;
            } else if (q->lshape == SAREG) {
                  static struct rspecial s[] = {
                        { NLEFT, R0 },
                        { NRIGHT, R1 },
                        { NRES, R0 },
                        { 0 }
                  };
                  return s;
            }
      case PLUS:
      case MINUS:
      case MUL:
#endif
      case MOD:
      case DIV:
            if (q->lshape == SBREG) {
                  static struct rspecial s[] = {
                        { NLEFT, R0R1 },
                        { NRIGHT, R2R3 },
                        { NRES, R0R1 },
                        { 0 }
                  };
                  return s;
            } else if (q->lshape == SAREG) {
                  static struct rspecial s[] = {
                        { NLEFT, R0 },
                        { NRIGHT, R1 },
                        { NRES, R0 },
                        { 0 }
                  };
                  return s;
            }
      case LS:
      case RS:
            if (q->lshape == SBREG) {
                  static struct rspecial s[] = {
                        { NLEFT, R0R1 },
                        { NRIGHT, R2 },
                        { NRES, R0R1 },
                        { 0 }
                  };
                  return s;
            } else if (q->lshape == SAREG) {
                  static struct rspecial s[] = {
                        { NLEFT, R0 },
                        { NRIGHT, R1 },
                        { NRES, R0 },
                        { 0 }
                  };
                  return s;
            }
      case STASG:
            {
                  static struct rspecial s[] = {
                        { NEVER, R0 },
                        { NRIGHT, R1 },
                        { NEVER, R2 },
                        { 0 } };
                  return s;
            }
            break;

      default:
            break;
      }

#ifdef PCC_DEBUG
      comperr("nspecial entry %d [0x%x]: %s", q - table, q->op, q->cstring);
#endif
      return 0; /* XXX gcc */
}

/*
 * Set evaluation order of a binary node ('+','-', '*', '/', etc) if it
 * differs from default.
 */
int
setorder(NODE *p)
{
      return 0;
}

/*
 * Set registers "live" at function calls (like arguments in registers).
 * This is for liveness analysis of registers.
 */
int *
livecall(NODE *p)
{
        static int r[] = { R3, R2, R1, R0, -1 };
      int num = 1;

      if (p->n_op != CALL && p->n_op != FORTCALL && p->n_op != STCALL)
            return &r[4-0];

        for (p = p->n_right; p->n_op == CM; p = p->n_left)
                num += szty(p->n_right->n_type);
        num += szty(p->n_right->n_type);

      num = (num > 4 ? 4 : num);

        return &r[4 - num];
}

/*
 * Signal whether the instruction is acceptable for this target.
 */
int
acceptable(struct optab *op)
{
      return features(op->visit & 0xffff0000);
}

Generated by  Doxygen 1.6.0   Back to index