ack/util/ego/sr/sr_aux.c
1987-03-09 19:15:41 +00:00

120 lines
2.4 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".
*/
/* S T R E N G T H R E D U C T I O N
*
* S R _ A U X . C
*
*/
#include "../share/types.h"
#include "sr.h"
#include "../share/debug.h"
#include "../../../h/em_mnem.h"
#include "../../../h/em_pseu.h"
#include "../share/global.h"
#include "../share/lset.h"
#include "../share/aux.h"
#include "sr_aux.h"
#include "sr_xform.h"
#define INSIDE_LOOP(b,lp) Lis_elem(b,lp->LP_BLOCKS)
bool is_loopconst(lnp,vars)
line_p lnp;
lset vars;
{
Lindex i;
assert(TYPE(lnp) == OPSHORT || TYPE(lnp) == OPOFFSET);
if (!is_regvar(off_set(lnp))) return FALSE;
for (i = Lfirst(vars); i != (Lindex) 0; i = Lnext(i,vars)) {
if (same_local(Lelem(i),lnp)) {
return FALSE; /* variable was changed */
}
}
return TRUE;
}
bool is_caddress(lnp,vars)
line_p lnp;
lset vars; /* variables changed in loop */
{
/* See if lnp is a single instruction (i.e. without arguments)
* that pushes a loop-invariant entity of size pointer-size (ps)
* on the stack.
*/
if (lnp == (line_p) 0) return FALSE;
switch(INSTR(lnp)) {
case op_lae:
case op_lal:
return TRUE;
case op_lol:
return ps == ws && is_loopconst(lnp,vars);
case op_ldl:
return ps == 2*ws && is_loopconst(lnp,vars);
default:
return FALSE;
}
/* NOTREACHED */
}
STATIC arg_p find_arg(n,list)
int n;
arg_p list;
{
/* Find the n-th element of the list */
while (--n) {
if (list == (arg_p) 0) break;
list = list->a_next;
}
return list;
}
int elemsize(lnp)
line_p lnp;
{
/* lnp is an instruction that loads the address of an array
* descriptor. Find the size of the elements of the array.
* If this size cannot be determined (e.g. the descriptor may
* not be in a rom) then return UNKNOWN_SIZE.
*/
dblock_p d;
arg_p v;
assert (lnp != (line_p) 0);
if (INSTR(lnp) == op_lae) {
d = OBJ(lnp)->o_dblock; /* datablock */
if (d->d_pseudo == DROM &&
(v = find_arg(3,d->d_values)) != (arg_p) 0 &&
v->a_type == ARGOFF) {
return (int) v->a_a.a_offset;
}
}
return UNKNOWN_SIZE;
}
concatenate(list1,list2)
line_p list1,list2;
{
/* Append list2 to the end of list1. list1 may not be empty. */
register line_p l;
assert(list1 != (line_p) 0);
for (l =list1; l->l_next != (line_p) 0; l = l->l_next);
l->l_next = list2;
}