OpenBSD-4.6/usr.bin/pcc/arm/order.c
/* $OpenBSD: order.c,v 1.3 2008/04/11 20:45:52 stefan 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 t, int r, CONSZ off, char *cp)
{
if (cp && cp[0]) return 1;
return !(off < 32768 && off > -32769); /* YES */
}
/*
* 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;
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)
{
/* Turns currently anything into OREG */
return SOREG;
}
/*
* 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);
}