ack/mach/proto/ncg/equiv.c
George Koehler e04166b85d More prototypes, less register in mach/proto/ncg
Files that #include "equiv.h" must do so after including "data.h", now
that a function prototype in equiv.h uses type rl_p from data.h.

Adjust style, changing some `for(...)` to `for (...)`.  The style in
mach/proto/ncg is less than consistent; the big annoyance now is that
some files want tabs at 4 spaces, others want tabs at 8 spaces.
2017-11-13 12:44:17 -05:00

99 lines
1.9 KiB
C

#ifndef NORCSID
static char rcsid[] = "$Id$";
#endif
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include "param.h"
#include "tables.h"
#include "types.h"
#include <cgg_cg.h>
#include "data.h"
#include "equiv.h"
#include "result.h"
#include "extern.h"
/*
* (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
*/
static int rar[MAXCREG];
static rl_p *lar;
static int maxindex;
static int regclass[NREGS];
static struct perm *perms;
static void permute(int);
struct perm *tuples(rl_p *regls, int nregneeded) {
int class=0;
int i,j;
struct reginfo *rp;
/*
* First compute equivalence classes of registers.
*/
for (i=NREGS, rp = &machregs[NREGS-1];--i>=0;rp--) {
regclass[i] = class++;
if (getrefcount(i, FALSE) == 0) {
for (j=NREGS;--j>i;) {
if (eqregclass(i,j) &&
eqtoken(&rp->r_contents,
&machregs[j].r_contents)) {
regclass[i] = regclass[j];
break;
}
}
}
}
/*
* Now create tuples through a recursive function
*/
maxindex = nregneeded;
lar = regls;
perms = 0;
permute(0);
return(perms);
}
static void permute(int index) {
struct perm *pp;
rl_p rlp;
int i,j;
if (index == maxindex) {
for (pp=perms; pp != 0; pp=pp->p_next) {
for (i=0; i<maxindex; i++)
if (regclass[rar[i]] != regclass[pp->p_rar[i]])
goto diff;
for (i=0; i<maxindex; i++) {
int rari = rar[i], p_rari = pp->p_rar[i];
for (j=0; j<i; j++)
if (clash(rari,rar[j]) !=
clash(p_rari,pp->p_rar[j]))
goto diff;
}
return;
diff: ;
}
pp = (struct perm *) myalloc(sizeof ( *pp ));
pp->p_next = perms;
for (i=0; i<maxindex; i++)
pp->p_rar[i] = rar[i];
perms = pp;
} else {
rlp=lar[index];
for (i=rlp->rl_n; i>0; i--) {
rar[index] = rlp->rl_list[rlp->rl_n-i];
permute(index+1);
}
}
}