ack/mach/proto/cg/move.c
2019-05-11 01:11:54 +08:00

98 lines
2.5 KiB
C

/*
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*
* Author: Hans van Staveren
*/
#include "assert.h"
#include "param.h"
#include "tables.h"
#include "types.h"
#include <cg_pattern.h>
#include "data.h"
#include "result.h"
#include "extern.h"
#include "subr.h"
#include "reg.h"
#include "codegen.h"
int move(token_p tp1,token_p tp2,int ply,int toplevel,unsigned int maxcost)
{
register move_p mp;
register unsigned t;
register struct reginfo *rp;
tkdef_p tdp;
int i;
if (eqtoken(tp1,tp2))
return(0);
if (tp2->t_token == -1) {
if (tp1->t_token == -1) {
if (eqtoken(&machregs[tp1->t_att[0].ar].r_contents,
&machregs[tp2->t_att[0].ar].r_contents) &&
machregs[tp1->t_att[0].ar].r_contents.t_token!=0)
return(0);
if (tp1->t_att[0].ar!=1) { /* COCO reg; tmp kludge */
erasereg(tp2->t_att[0].ar);
machregs[tp2->t_att[0].ar].r_contents =
machregs[tp1->t_att[0].ar].r_contents ;
} else
machregs[tp1->t_att[0].ar].r_contents =
machregs[tp2->t_att[0].ar].r_contents ;
} else {
if (eqtoken(&machregs[tp2->t_att[0].ar].r_contents,tp1))
return(0);
erasereg(tp2->t_att[0].ar);
machregs[tp2->t_att[0].ar].r_contents = *tp1;
}
for (rp=machregs;rp<machregs+NREGS;rp++) {
if (rp->r_contents.t_token == 0)
continue;
assert(rp->r_contents.t_token > 0);
tdp = &tokens[rp->r_contents.t_token];
for (i=0;i<TOKENSIZE;i++)
if (tdp->t_type[i] == EV_REG &&
clash(rp->r_contents.t_att[i].ar,tp2->t_att[0].ar)) {
erasereg((int)(rp-machregs));
break;
}
}
} else if (tp1->t_token == -1) {
if (eqtoken(tp2,&machregs[tp1->t_att[0].ar].r_contents))
return(0);
machregs[tp1->t_att[0].ar].r_contents = *tp2;
}
/*
* If we arrive here the move must really be executed
*/
for (mp=moves;mp<moves+NMOVES;mp++) {
if (!match(tp1,&machsets[mp->m_set1],mp->m_expr1))
continue;
if (match(tp2,&machsets[mp->m_set2],mp->m_expr2))
break;
/*
* Correct move rule is found
*/
}
assert(mp<moves+NMOVES);
/*
* To get correct interpretation of things like %[1]
* in move code we stack tp2 and tp1. This little trick
* saves a lot of testing in other places.
*/
if (mp->m_cindex!=0) {
fakestack[stackheight] = *tp2;
fakestack[stackheight+1] = *tp1;
stackheight += 2;
t = codegen(&coderules[mp->m_cindex],ply,toplevel,maxcost,0);
if (t <= maxcost)
t += costcalc(mp->m_cost);
stackheight -= 2;
} else {
t = 0;
}
return(t);
}