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/*
Crown Copyright (c) 1997
This TenDRA(r) Computer Program is subject to Copyright
owned by the United Kingdom Secretary of State for Defence
acting through the Defence Evaluation and Research Agency
(DERA). It is made available to Recipients with a
royalty-free licence for its use, reproduction, transfer
to other parties and amendment for any purpose not excluding
product development provided that any such use et cetera
shall be deemed to be acceptance of the following conditions:-
(1) Its Recipients shall ensure that this Notice is
reproduced upon any copies or amended versions of it;
(2) Any amended version of it shall be clearly marked to
show both the nature of and the organisation responsible
for the relevant amendment or amendments;
(3) Its onward transfer from a recipient to another
party shall be deemed to be that party's acceptance of
these conditions;
(4) DERA gives no warranty or assurance as to its
quality or suitability for any purpose and DERA accepts
no liability whatsoever in relation to any use to which
it may be put.
*/
/* 80x86/reg_record.c */
/**********************************************************************
$Author: pwe $
$Date: 1998/03/15 16:00:22 $
$Revision: 1.3 $
$Log: reg_record.c,v $
* Revision 1.3 1998/03/15 16:00:22 pwe
* regtrack dwarf dagnostics added
*
* Revision 1.2 1998/02/02 11:18:25 pwe
* 80x86 shape_overlap correction
*
* Revision 1.1.1.1 1998/01/17 15:55:52 release
* First version to be checked into rolling release.
*
* Revision 1.4 1996/12/10 15:41:17 pwe
* check condition at invalidate_dest
*
* Revision 1.3 1995/04/03 08:30:28 pwe
* invalidate regs if overlap, eg if bitfield on byte boundaries
*
* Revision 1.2 1995/01/30 12:56:44 pwe
* Ownership -> PWE, tidy banners
*
* Revision 1.1 1994/10/27 14:15:22 jmf
* Initial revision
*
* Revision 1.1 1994/07/12 14:39:53 jmf
* Initial revision
*
**********************************************************************/
#include "config.h"
#include "common_types.h"
#include "operand.h"
#include "tags.h"
#include "exp.h"
#include "expmacs.h"
#include "instr386.h"
#include "shapemacs.h"
#include "codermacs.h"
#include "flags.h"
#ifdef NEWDWARF
#include "dw2_extra.h"
#endif
#include "reg_record.h"
/* This collection of routines maintains a record of what is known to
to be in each register during code production
*/
/* VARIABLES */
/* All variables initialised */
reg_record crt_reg_record;
/* init by cproc */
/* PROCEDURES */
/* clear out all the register records */
void clear_reg_record
PROTO_N ( (s) )
PROTO_T ( regcell * s )
{
int i;
for (i = 0; i < no_fixed_regs; ++i) {
s[i].regcell_key = 4;
#ifdef NEWDWARF
if (dwarf2) {
dw_close_regassn (i, 0);
dw_close_regassn (i, 1);
}
#endif
}
return;
}
/* clear out the registers not preserved
over procedure calls */
void clear_low_reg_record
PROTO_N ( (s) )
PROTO_T ( regcell * s )
{
int i;
for (i = 0; i < no_fixed_regs; ++i) {
s[i].regcell_key = 4;
#ifdef NEWDWARF
if (dwarf2) {
dw_close_regassn (i, 0);
dw_close_regassn (i, 1);
}
#endif
}
return;
}
/* true if changing d invalidates r */
static int inval
PROTO_N ( (d, r) )
PROTO_T ( exp d X exp r )
{
if ((d == nilexp || name (d) == cont_tag) &&
(name (r) == cont_tag || (name (r) == name_tag && isglob (son (r)))))
return (1);
if ((name (r) == name_tag && !isvar (son (r))) ||
name (r) == cont_tag)
return (eq_where (mw (d, 0), mw (r, 0)));
if (name (r) == reff_tag)
return (inval (d, son (r)));
if (name (r) == addptr_tag) {
if (name (bro (son (r))) == offset_mult_tag)
return (inval (d, son (r)) || inval (d, son (bro (son (r)))));
return (inval (d, son (r)) || inval (d, bro (son (r))));
};
if (name (r) == ident_tag)
return (inval (d, son (r)) || inval (d, bro (son (r))));
return (0);
}
/* true if changing d invalidates r */
int invalidates
PROTO_N ( (d, r) )
PROTO_T ( exp d X exp r )
{
if (name (r) == cont_tag || name (r) == ass_tag)
return (inval (d, son (r)));
return (0);
}
/* convert register mask to register number */
static int get_regno
PROTO_N ( (mask) )
PROTO_T ( int mask )
{
int m = 1;
int res;
for (res = 0; res < no_fixed_regs && (mask & m) == 0; res++)
m = m + m;
return (res);
}
/* if there is a register holding the same
value as is in w, return this register
(as a where), otherwise the where_exp
field of the result will be nilexp */
where equiv_reg
PROTO_N ( (w, sz) )
PROTO_T ( where w X int sz )
{
int i;
where res;
res.where_exp = nilexp;
if (w.where_off != 0)
return (res);
for (i = 0; i < no_fixed_regs; i++) {
regcell * p = &crt_reg_record[i];
if ((p -> regcell_key & 1) &&
(sz == 0 || sz == p -> first_size) &&
eq_where_exp (p -> first_dest, w.where_exp, 1, (sz==0))) {
#ifdef NEWDWARF
if (dwarf2)
dw_used_regassn (i, 0);
#endif
return (reg_wheres[i]);
}
if ((p -> regcell_key & 2) &&
(sz == 0 || sz == p -> second_size) &&
eq_where_exp (p -> second_dest, w.where_exp, 1, (sz==0))) {
#ifdef NEWDWARF
if (dwarf2)
dw_used_regassn (i, 1);
#endif
return (reg_wheres[i]);
}
};
res.where_exp = nilexp;
return (res);
}
static int is_aliased
PROTO_N ( (dest) )
PROTO_T ( exp dest )
{
if (dest == nilexp)
return 0;
if (name (dest) != cont_tag &&
name (dest) != ass_tag)
return (0);
if (name (son (dest)) == name_tag &&
isvar (son (son (dest))) &&
iscaonly (son (son (dest))))
return (0);
return (1);
}
static int shape_overlap
PROTO_N ( (e1, e2) )
PROTO_T ( exp e1 X exp e2 )
{
shape s1 = sh (e1);
shape s2 = sh (e2);
if (name (s1) <= doublehd && name (s1) > tophd && name (s2) == ptrhd)
return (0);
if (name (s2) <= doublehd && name (s2) > tophd && name (s1) == ptrhd)
return (0);
return (1);
}
/* make changes to the register record
needed when dest receives an unknown
value */
void invalidate_dest
PROTO_N ( (dest) )
PROTO_T ( where dest )
{
exp d = dest.where_exp;
int regmask = (d == nilexp) ? 0 : (in_reg (d) & 0x7fffffff);
int regno;
where weq;
int i;
/* this repeats the condition state check at start of move,
in case contop has reset it */
if ((cond1_set && (eq_where (dest, cond1) ||
invalidates (dest.where_exp, cond1.where_exp))) ||
(cond2_set &&
(eq_where (dest, cond2a) || eq_where (dest, cond2b) ||
invalidates (dest.where_exp, cond2a.where_exp) ||
invalidates (dest.where_exp, cond2b.where_exp)))) {
cond1_set = 0;
cond2_set = 0;
};
if (is_aliased (dest.where_exp)) {
for (i = 0; i < no_fixed_regs; ++i) {
regcell * pr = &crt_reg_record[i];
switch (pr -> regcell_key) {
case 1:
if (is_aliased (pr -> first_dest) &&
shape_overlap (dest.where_exp, pr -> first_dest)) {
pr -> regcell_key = 4;
#ifdef NEWDWARF
if (dwarf2)
dw_close_regassn (i, 0);
#endif
}
break;
case 2:
if (is_aliased (pr -> second_dest) &&
shape_overlap (dest.where_exp, pr -> second_dest)) {
pr -> regcell_key = 4;
#ifdef NEWDWARF
if (dwarf2)
dw_close_regassn (i, 1);
#endif
}
break;
case 3:
if (is_aliased (pr -> first_dest) &&
shape_overlap (dest.where_exp, pr -> first_dest)) {
pr -> regcell_key &= 2;
#ifdef NEWDWARF
if (dwarf2)
dw_close_regassn (i, 0);
#endif
}
if (is_aliased (pr -> second_dest) &&
shape_overlap (dest.where_exp, pr -> second_dest)) {
pr -> regcell_key &= 1;
#ifdef NEWDWARF
if (dwarf2)
dw_close_regassn (i, 1);
#endif
}
if (pr -> regcell_key == 0)
pr -> regcell_key = 4;
default: ;
};
};
};
if (regmask) {
regno = get_regno (regmask);
if (regno < no_fixed_regs)
crt_reg_record[regno].regcell_key = 4;
};
if (regmask || d == nilexp) {
for (i = 0; i < no_fixed_regs; ++i) {
regcell * pr = &crt_reg_record[i];
switch (pr -> regcell_key) {
case 1:
if (invalidates (d, pr -> first_dest)) {
pr -> regcell_key = 4;
#ifdef NEWDWARF
if (dwarf2)
dw_close_regassn (i, 0);
#endif
}
break;
case 2:
if (invalidates (d, pr -> second_dest)) {
pr -> regcell_key = 4;
#ifdef NEWDWARF
if (dwarf2)
dw_close_regassn (i, 1);
#endif
}
break;
case 3:
if (invalidates (d, pr -> first_dest)) {
pr -> regcell_key &= 2;
#ifdef NEWDWARF
if (dwarf2)
dw_close_regassn (i, 0);
#endif
}
if (invalidates (d, pr -> second_dest)) {
pr -> regcell_key &= 1;
#ifdef NEWDWARF
if (dwarf2)
dw_close_regassn (i, 1);
#endif
}
if (pr -> regcell_key == 0)
pr -> regcell_key = 4;
default: ;
};
};
return;
};
#ifdef NEWDWARF
dw_ignore_used_regassn = 1;
#endif
while (1) {
weq = equiv_reg (dest, 0);
if (weq.where_exp == nilexp)
break;
regmask = (in_reg (weq.where_exp) & 0x7fffffff);
regno = get_regno (regmask);
if (regno < no_fixed_regs)
crt_reg_record[regno].regcell_key = 4;
};
#ifdef NEWDWARF
dw_ignore_used_regassn = 0;
#endif
return;
}
/* from is being moved to to. Make changes
to the register records accordingly */
void move_reg
PROTO_N ( (from, to, sha) )
PROTO_T ( where from X where to X shape sha )
{
int regmask_to = in_reg (to.where_exp);
int regmask_from = in_reg (from.where_exp);
int sz = shape_size(sha);
if (name(sha) == shrealhd)
return;
if (regmask_from != 0 && regmask_to != 0)
return;
if ((regmask_from & (int)0x80000000) || (regmask_to & (int)0x80000000))
return;
if (from.where_off != 0 || to.where_off != 0)
return;
if (regmask_to && invalidates (to.where_exp, from.where_exp))
return;
if (regmask_to && regmask_to < 64) {
int regno_to = get_regno (regmask_to);
regcell * p = &crt_reg_record[regno_to];
switch (p -> regcell_key) {
case 1:
{
p -> regcell_key = 3;
p -> second_dest = from.where_exp;
p -> second_size = sz;
#ifdef NEWDWARF
if (dwarf2)
dw_init_regassn (regno_to, 1);
#endif
break;
};
case 2:
{
p -> regcell_key = 3;
p -> first_dest = from.where_exp;
p -> first_size = sz;
#ifdef NEWDWARF
if (dwarf2)
dw_init_regassn (regno_to, 0);
#endif
break;
};
case 3:
break;
default:
{
p -> regcell_key = 1;
p -> first_dest = from.where_exp;
p -> first_size = sz;
#ifdef NEWDWARF
if (dwarf2)
dw_init_regassn (regno_to, 0);
#endif
break;
};
};
};
if (regmask_from && regmask_from < 64) {
int regno_from = get_regno (regmask_from);
regcell * p = &crt_reg_record[regno_from];
switch (p -> regcell_key) {
case 1:
{
p -> regcell_key = 3;
p -> second_dest = to.where_exp;
p -> second_size = sz;
#ifdef NEWDWARF
if (dwarf2)
dw_init_regassn (regno_from, 1);
#endif
break;
};
case 2:
{
p -> regcell_key = 3;
p -> first_dest = to.where_exp;
p -> first_size = sz;
#ifdef NEWDWARF
if (dwarf2)
dw_init_regassn (regno_from, 0);
#endif
break;
};
case 3:
break;
default:
{
p -> regcell_key = 1;
p -> first_dest = to.where_exp;
p -> first_size = sz;
#ifdef NEWDWARF
if (dwarf2)
dw_init_regassn (regno_from, 0);
#endif
break;
};
};
};
}