591 lines
12 KiB
C
591 lines
12 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: Ceriel J.H. Jacobs
|
|
*/
|
|
|
|
/* D E S I G N A T O R E V A L U A T I O N */
|
|
|
|
/* $Header$ */
|
|
|
|
/* Code generation for designators.
|
|
This file contains some routines that generate code common to address
|
|
as well as value computations, and leave a description in a "desig"
|
|
structure. It also contains routines to load an address, load a value
|
|
or perform a store.
|
|
*/
|
|
|
|
#include "debug.h"
|
|
|
|
#include <em_arith.h>
|
|
#include <em_label.h>
|
|
#include <em_code.h>
|
|
#include <assert.h>
|
|
|
|
#include "type.h"
|
|
#include "def.h"
|
|
#include "scope.h"
|
|
#include "desig.h"
|
|
#include "LLlex.h"
|
|
#include "node.h"
|
|
|
|
extern int proclevel;
|
|
struct desig InitDesig = {DSG_INIT, 0, 0, 0};
|
|
|
|
int C_ste_dnam(), C_sde_dnam(), C_loe_dnam(), C_lde_dnam();
|
|
int C_stl(), C_sdl(), C_lol(), C_ldl();
|
|
|
|
#define WRD 0
|
|
#define DWRD 1
|
|
#define LD 0
|
|
#define STR 1
|
|
|
|
static int (*lcl_ld_and_str[2][2])() = {
|
|
{ C_lol, C_stl },
|
|
{ C_ldl, C_sdl }
|
|
};
|
|
|
|
static int (*ext_ld_and_str[2][2])() = {
|
|
{ C_loe_dnam, C_ste_dnam },
|
|
{ C_lde_dnam, C_sde_dnam }
|
|
};
|
|
|
|
int
|
|
DoLoadOrStore(ds, size, LoadOrStoreFlag)
|
|
register struct desig *ds;
|
|
arith size;
|
|
{
|
|
int sz;
|
|
|
|
if (ds->dsg_offset % word_size != 0) return 0;
|
|
|
|
if (size == word_size) sz = WRD;
|
|
else if (size == dword_size) sz = DWRD;
|
|
else return 0;
|
|
|
|
if (ds->dsg_name) {
|
|
(*(ext_ld_and_str[sz][LoadOrStoreFlag]))(ds->dsg_name, ds->dsg_offset);
|
|
}
|
|
else {
|
|
(*(lcl_ld_and_str[sz][LoadOrStoreFlag]))(ds->dsg_offset);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
STATIC int
|
|
properly(ds, size, al)
|
|
register struct desig *ds;
|
|
arith size;
|
|
{
|
|
/* Check if it is allowed to load or store the value indicated
|
|
by "ds" with LOI/STI.
|
|
- if the size is not either a multiple or a dividor of the
|
|
wordsize, then not.
|
|
- if the alignment is at least "word" then OK.
|
|
- if size is dividor of word_size and alignment >= size then OK.
|
|
- otherwise check alignment of address. This can only be done
|
|
with DSG_FIXED.
|
|
*/
|
|
|
|
arith szmodword = size % word_size; /* 0 if multiple of wordsize */
|
|
arith wordmodsz = word_size % size; /* 0 if dividor of wordsize */
|
|
|
|
if (szmodword && wordmodsz) return 0;
|
|
if (al >= word_align) return 1;
|
|
if (szmodword && al >= szmodword) return 1;
|
|
|
|
return ds->dsg_kind == DSG_FIXED &&
|
|
((! szmodword && ds->dsg_offset % word_align == 0) ||
|
|
(! wordmodsz && ds->dsg_offset % size == 0));
|
|
}
|
|
|
|
CodeValue(ds, size, al)
|
|
register struct desig *ds;
|
|
arith size;
|
|
{
|
|
/* Generate code to load the value of the designator described
|
|
in "ds"
|
|
*/
|
|
|
|
switch(ds->dsg_kind) {
|
|
case DSG_LOADED:
|
|
break;
|
|
|
|
case DSG_FIXED:
|
|
if (DoLoadOrStore(ds, size, LD)) break;
|
|
/* Fall through */
|
|
case DSG_PLOADED:
|
|
case DSG_PFIXED:
|
|
if (properly(ds, size, al)) {
|
|
CodeAddress(ds);
|
|
C_loi(size);
|
|
break;
|
|
}
|
|
if (ds->dsg_kind == DSG_PLOADED) {
|
|
arith sz = WA(size) - pointer_size;
|
|
|
|
C_asp(-sz);
|
|
C_lor((arith) 1);
|
|
C_adp(sz);
|
|
C_loi(pointer_size);
|
|
}
|
|
else {
|
|
C_asp(-WA(size));
|
|
CodeAddress(ds);
|
|
}
|
|
C_loc(size);
|
|
C_cal("_load");
|
|
C_asp(2 * word_size);
|
|
break;
|
|
|
|
case DSG_INDEXED:
|
|
C_lar(word_size);
|
|
break;
|
|
|
|
default:
|
|
crash("(CodeValue)");
|
|
}
|
|
|
|
ds->dsg_kind = DSG_LOADED;
|
|
}
|
|
|
|
CodeStore(ds, size, al)
|
|
register struct desig *ds;
|
|
arith size;
|
|
{
|
|
/* Generate code to store the value on the stack in the designator
|
|
described in "ds"
|
|
*/
|
|
struct desig save;
|
|
|
|
save = *ds;
|
|
switch(ds->dsg_kind) {
|
|
case DSG_FIXED:
|
|
if (DoLoadOrStore(ds, size, STR)) break;
|
|
/* Fall through */
|
|
case DSG_PLOADED:
|
|
case DSG_PFIXED:
|
|
CodeAddress(&save);
|
|
if (properly(ds, size, al)) {
|
|
C_sti(size);
|
|
break;
|
|
}
|
|
C_loc(size);
|
|
C_cal("_store");
|
|
C_asp(2 * word_size + WA(size));
|
|
break;
|
|
|
|
case DSG_INDEXED:
|
|
C_sar(word_size);
|
|
break;
|
|
|
|
default:
|
|
crash("(CodeStore)");
|
|
}
|
|
|
|
ds->dsg_kind = DSG_INIT;
|
|
}
|
|
|
|
CodeCopy(lhs, rhs, sz, psize)
|
|
register struct desig *lhs, *rhs;
|
|
arith sz, *psize;
|
|
{
|
|
struct desig l, r;
|
|
|
|
l = *lhs; r = *rhs;
|
|
*psize -= sz;
|
|
lhs->dsg_offset += sz;
|
|
rhs->dsg_offset += sz;
|
|
CodeAddress(&r);
|
|
C_loi(sz);
|
|
CodeAddress(&l);
|
|
C_sti(sz);
|
|
}
|
|
|
|
CodeMove(rhs, left, rtp)
|
|
register struct desig *rhs;
|
|
register struct node *left;
|
|
struct type *rtp;
|
|
{
|
|
struct desig dsl;
|
|
register struct desig *lhs = &dsl;
|
|
register struct type *tp = left->nd_type;
|
|
int loadedflag = 0;
|
|
|
|
dsl = InitDesig;
|
|
|
|
/* Generate code for an assignment. Testing of type
|
|
compatibility and the like is already done.
|
|
Go through some (considerable) trouble to see if a BLM can be
|
|
generated.
|
|
*/
|
|
|
|
switch(rhs->dsg_kind) {
|
|
case DSG_LOADED:
|
|
CodeDesig(left, lhs);
|
|
if (rtp->tp_fund == T_STRING) {
|
|
CodeAddress(lhs);
|
|
C_loc(rtp->tp_size);
|
|
C_loc(tp->tp_size);
|
|
C_cal("_StringAssign");
|
|
C_asp(word_size << 2);
|
|
return;
|
|
}
|
|
CodeStore(lhs, tp->tp_size, tp->tp_align);
|
|
return;
|
|
case DSG_PLOADED:
|
|
case DSG_PFIXED:
|
|
CodeAddress(rhs);
|
|
if (tp->tp_size % word_size == 0 && tp->tp_align >= word_size) {
|
|
CodeDesig(left, lhs);
|
|
CodeAddress(lhs);
|
|
C_blm(tp->tp_size);
|
|
return;
|
|
}
|
|
CodeValue(rhs, tp->tp_size, tp->tp_align);
|
|
CodeDStore(left);
|
|
return;
|
|
case DSG_FIXED:
|
|
CodeDesig(left, lhs);
|
|
if (lhs->dsg_kind == DSG_FIXED &&
|
|
lhs->dsg_offset % word_size ==
|
|
rhs->dsg_offset % word_size) {
|
|
register arith sz;
|
|
arith size = tp->tp_size;
|
|
|
|
while (size && (sz = (lhs->dsg_offset % word_size))) {
|
|
/* First copy up to word-aligned
|
|
boundaries
|
|
*/
|
|
if (sz < 0) sz = -sz; /* bloody '%' */
|
|
while (word_size % sz) sz--;
|
|
CodeCopy(lhs, rhs, sz, &size);
|
|
}
|
|
if (size > 3*dword_size) {
|
|
/* Do a block move
|
|
*/
|
|
struct desig l, r;
|
|
|
|
sz = (size / word_size) * word_size;
|
|
l = *lhs; r = *rhs;
|
|
CodeAddress(&r);
|
|
CodeAddress(&l);
|
|
C_blm(sz);
|
|
rhs->dsg_offset += sz;
|
|
lhs->dsg_offset += sz;
|
|
size -= sz;
|
|
}
|
|
else for (sz = dword_size; sz; sz -= word_size) {
|
|
while (size >= sz) {
|
|
/* Then copy dwords, words.
|
|
Depend on peephole optimizer
|
|
*/
|
|
CodeCopy(lhs, rhs, sz, &size);
|
|
}
|
|
}
|
|
sz = word_size;
|
|
while (size && --sz) {
|
|
/* And then copy remaining parts
|
|
*/
|
|
while (word_size % sz) sz--;
|
|
while (size >= sz) {
|
|
CodeCopy(lhs, rhs, sz, &size);
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
if (lhs->dsg_kind == DSG_PLOADED ||
|
|
lhs->dsg_kind == DSG_INDEXED) {
|
|
CodeAddress(lhs);
|
|
loadedflag = 1;
|
|
}
|
|
if (tp->tp_size % word_size == 0 && tp->tp_align >= word_size) {
|
|
CodeAddress(rhs);
|
|
if (loadedflag) C_exg(pointer_size);
|
|
else CodeAddress(lhs);
|
|
C_blm(tp->tp_size);
|
|
return;
|
|
}
|
|
{
|
|
arith tmp;
|
|
extern arith NewPtr();
|
|
|
|
if (loadedflag) {
|
|
tmp = NewPtr();
|
|
lhs->dsg_offset = tmp;
|
|
lhs->dsg_name = 0;
|
|
lhs->dsg_kind = DSG_PFIXED;
|
|
lhs->dsg_def = 0;
|
|
C_stl(tmp); /* address of lhs */
|
|
}
|
|
CodeValue(rhs, tp->tp_size, tp->tp_align);
|
|
CodeStore(lhs, tp->tp_size, tp->tp_align);
|
|
if (loadedflag) FreePtr(tmp);
|
|
return;
|
|
}
|
|
default:
|
|
crash("CodeMove");
|
|
}
|
|
}
|
|
|
|
CodeAddress(ds)
|
|
register struct desig *ds;
|
|
{
|
|
/* Generate code to load the address of the designator described
|
|
in "ds"
|
|
*/
|
|
|
|
switch(ds->dsg_kind) {
|
|
case DSG_PLOADED:
|
|
if (ds->dsg_offset) {
|
|
C_adp(ds->dsg_offset);
|
|
}
|
|
break;
|
|
|
|
case DSG_FIXED:
|
|
if (ds->dsg_name) {
|
|
C_lae_dnam(ds->dsg_name, ds->dsg_offset);
|
|
break;
|
|
}
|
|
C_lal(ds->dsg_offset);
|
|
if (ds->dsg_def) ds->dsg_def->df_flags |= D_NOREG;
|
|
break;
|
|
|
|
case DSG_PFIXED:
|
|
DoLoadOrStore(ds, word_size, LD);
|
|
break;
|
|
|
|
case DSG_INDEXED:
|
|
C_aar(word_size);
|
|
break;
|
|
|
|
default:
|
|
crash("(CodeAddress)");
|
|
}
|
|
|
|
ds->dsg_offset = 0;
|
|
ds->dsg_kind = DSG_PLOADED;
|
|
}
|
|
|
|
CodeFieldDesig(df, ds)
|
|
register struct def *df;
|
|
register struct desig *ds;
|
|
{
|
|
/* Generate code for a field designator. Only the code common for
|
|
address as well as value computation is generated, and the
|
|
resulting information on where to find the designator is placed
|
|
in "ds". "df" indicates the definition of the field.
|
|
*/
|
|
|
|
if (ds->dsg_kind == DSG_INIT) {
|
|
/* In a WITH statement. We must find the designator in the
|
|
WITH statement, and act as if the field is a selection
|
|
of this designator.
|
|
So, first find the right WITH statement, which is the
|
|
first one of the proper record type, which is
|
|
recognized by its scope indication.
|
|
*/
|
|
register struct withdesig *wds = WithDesigs;
|
|
|
|
assert(wds != 0);
|
|
|
|
while (wds->w_scope != df->df_scope) {
|
|
wds = wds->w_next;
|
|
assert(wds != 0);
|
|
}
|
|
|
|
/* Found it. Now, act like it was a selection.
|
|
*/
|
|
*ds = wds->w_desig;
|
|
assert(ds->dsg_kind == DSG_PFIXED);
|
|
}
|
|
|
|
switch(ds->dsg_kind) {
|
|
case DSG_PLOADED:
|
|
case DSG_FIXED:
|
|
ds->dsg_offset += df->fld_off;
|
|
break;
|
|
|
|
case DSG_PFIXED:
|
|
case DSG_INDEXED:
|
|
CodeAddress(ds);
|
|
ds->dsg_kind = DSG_PLOADED;
|
|
ds->dsg_offset = df->fld_off;
|
|
break;
|
|
|
|
default:
|
|
crash("(CodeFieldDesig)");
|
|
}
|
|
}
|
|
|
|
CodeVarDesig(df, ds)
|
|
register struct def *df;
|
|
register struct desig *ds;
|
|
{
|
|
/* Generate code for a variable represented by a "def" structure.
|
|
Of course, there are numerous cases: the variable is local,
|
|
it is a value parameter, it is a var parameter, it is one of
|
|
those of an enclosing procedure, or it is global.
|
|
*/
|
|
register struct scope *sc = df->df_scope;
|
|
|
|
/* Selections from a module are handled earlier, when identifying
|
|
the variable, so ...
|
|
*/
|
|
assert(ds->dsg_kind == DSG_INIT);
|
|
|
|
if (df->var_addrgiven) {
|
|
/* the programmer specified an address in the declaration of
|
|
the variable. Generate code to push the address.
|
|
*/
|
|
CodeConst(df->var_off, pointer_size);
|
|
ds->dsg_kind = DSG_PLOADED;
|
|
ds->dsg_offset = 0;
|
|
return;
|
|
}
|
|
|
|
if (df->var_name) {
|
|
/* this variable has been given a name, so it is global.
|
|
It is directly accessible.
|
|
*/
|
|
ds->dsg_name = df->var_name;
|
|
ds->dsg_offset = 0;
|
|
ds->dsg_kind = DSG_FIXED;
|
|
return;
|
|
}
|
|
|
|
if (sc->sc_level != proclevel) {
|
|
/* the variable is local to a statically enclosing procedure.
|
|
*/
|
|
assert(proclevel > sc->sc_level);
|
|
|
|
df->df_flags |= D_NOREG;
|
|
if (df->df_flags & (D_VARPAR|D_VALPAR)) {
|
|
/* value or var parameter
|
|
*/
|
|
C_lxa((arith) (proclevel - sc->sc_level));
|
|
if ((df->df_flags & D_VARPAR) ||
|
|
IsConformantArray(df->df_type)) {
|
|
/* var parameter or conformant array.
|
|
For conformant array's, the address is
|
|
passed.
|
|
*/
|
|
C_adp(df->var_off);
|
|
C_loi(pointer_size);
|
|
ds->dsg_offset = 0;
|
|
ds->dsg_kind = DSG_PLOADED;
|
|
return;
|
|
}
|
|
}
|
|
else C_lxl((arith) (proclevel - sc->sc_level));
|
|
ds->dsg_kind = DSG_PLOADED;
|
|
ds->dsg_offset = df->var_off;
|
|
return;
|
|
}
|
|
|
|
/* Now, finally, we have a local variable or a local parameter
|
|
*/
|
|
if ((df->df_flags & D_VARPAR) || IsConformantArray(df->df_type)) {
|
|
/* a var parameter; address directly accessible.
|
|
*/
|
|
ds->dsg_kind = DSG_PFIXED;
|
|
}
|
|
else ds->dsg_kind = DSG_FIXED;
|
|
ds->dsg_offset = df->var_off;
|
|
ds->dsg_def = df;
|
|
}
|
|
|
|
CodeDesig(nd, ds)
|
|
register struct node *nd;
|
|
register struct desig *ds;
|
|
{
|
|
/* Generate code for a designator. Use divide and conquer
|
|
principle
|
|
*/
|
|
register struct def *df;
|
|
|
|
switch(nd->nd_class) { /* Divide */
|
|
case Def:
|
|
df = nd->nd_def;
|
|
|
|
switch(df->df_kind) {
|
|
case D_FIELD:
|
|
CodeFieldDesig(df, ds);
|
|
break;
|
|
|
|
case D_VARIABLE:
|
|
CodeVarDesig(df, ds);
|
|
break;
|
|
|
|
default:
|
|
crash("(CodeDesig) Def");
|
|
}
|
|
break;
|
|
|
|
case LinkDef:
|
|
assert(nd->nd_symb == '.');
|
|
|
|
CodeDesig(nd->nd_left, ds);
|
|
CodeFieldDesig(nd->nd_def, ds);
|
|
break;
|
|
|
|
case Arrsel:
|
|
assert(nd->nd_symb == '[');
|
|
|
|
CodeDesig(nd->nd_left, ds);
|
|
CodeAddress(ds);
|
|
CodePExpr(nd->nd_right);
|
|
if (nd->nd_right->nd_type->tp_size > word_size) {
|
|
CodeCoercion(nd->nd_right->nd_type, int_type);
|
|
}
|
|
|
|
/* Now load address of descriptor
|
|
*/
|
|
if (IsConformantArray(nd->nd_left->nd_type)) {
|
|
assert(nd->nd_left->nd_class == Def);
|
|
|
|
df = nd->nd_left->nd_def;
|
|
if (proclevel > df->df_scope->sc_level) {
|
|
C_lxa((arith) (proclevel - df->df_scope->sc_level));
|
|
C_adp(df->var_off + pointer_size);
|
|
}
|
|
else C_lal(df->var_off + pointer_size);
|
|
}
|
|
else {
|
|
C_lae_dlb(nd->nd_left->nd_type->arr_descr, (arith) 0);
|
|
}
|
|
ds->dsg_kind = DSG_INDEXED;
|
|
break;
|
|
|
|
case Arrow:
|
|
assert(nd->nd_symb == '^');
|
|
|
|
CodeDesig(nd->nd_right, ds);
|
|
switch(ds->dsg_kind) {
|
|
case DSG_LOADED:
|
|
ds->dsg_kind = DSG_PLOADED;
|
|
break;
|
|
|
|
case DSG_INDEXED:
|
|
case DSG_PLOADED:
|
|
case DSG_PFIXED:
|
|
CodeValue(ds, pointer_size, pointer_align);
|
|
ds->dsg_kind = DSG_PLOADED;
|
|
ds->dsg_offset = 0;
|
|
break;
|
|
|
|
case DSG_FIXED:
|
|
ds->dsg_kind = DSG_PFIXED;
|
|
break;
|
|
|
|
default:
|
|
crash("(CodeDesig) Uoper");
|
|
}
|
|
break;
|
|
|
|
default:
|
|
crash("(CodeDesig) class");
|
|
}
|
|
}
|