quakeforge/tools/qfcc/source/switch.c
Bill Currie 06d70a32db [qfcc] Rework the functionality of address expressions
The goal was to get lea being used for locals in ruamoko progs because
lea takes the base registers into account while the constant pointer
defs used by v6p cannot. Pointer defs are still used for gobals as they
may be out of reach of 16-bit addressing.

address_expr() has been simplified in that it no longer takes an offset:
the vast majority of the callers never passed one, and the few that did
have been reworked to use other mechanisms. In particular,
offset_pointer_expr does the manipulations needed to add an offset
(unscaled by type size) to a pointer. High-level pointer offsets still
apply a scale, though.

Alias expressions now do a better job of hanling aliasing of aliases by
simply replacing the target type when possible.
2022-01-25 23:39:17 +09:00

465 lines
12 KiB
C

/*
switch.c
qc switch statement support
Copyright (C) 2001 Bill Currie <bill@taniwha.org>
Author: Bill Currie <bill@taniwha.org>
Date: 2001/10/24
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to:
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#include <stdlib.h>
#include <QF/hash.h>
#include <QF/sys.h>
#include "tools/qfcc/include/def.h"
#include "tools/qfcc/include/diagnostic.h"
#include "tools/qfcc/include/expr.h"
#include "tools/qfcc/include/opcodes.h"
#include "tools/qfcc/include/options.h"
#include "tools/qfcc/include/qfcc.h"
#include "tools/qfcc/include/reloc.h"
#include "tools/qfcc/include/shared.h"
#include "tools/qfcc/include/switch.h"
#include "tools/qfcc/include/symtab.h"
#include "tools/qfcc/include/type.h"
#include "tools/qfcc/source/qc-parse.h"
typedef struct case_node_s {
expr_t *low;
expr_t *high;
expr_t **labels;
expr_t *_label;
struct case_node_s *left, *right;
} case_node_t;
static __attribute__((pure)) ex_value_t *
get_value (expr_t *e)
{
if (e->type == ex_symbol)
return e->e.symbol->s.value;
if (e->type != ex_value)
internal_error (e, "bogus case label");
return e->e.value;
}
static __attribute__((pure)) uintptr_t
get_hash (const void *_cl, void *unused)
{
case_label_t *cl = (case_label_t *) _cl;
ex_value_t *val;
if (!cl->value)
return 0;
val = get_value (cl->value);
return Hash_Buffer (&val->v, sizeof (val->v)) + val->lltype;
}
static int
compare (const void *_cla, const void *_clb, void *unused)
{
case_label_t *cla = (case_label_t *) _cla;
case_label_t *clb = (case_label_t *) _clb;
expr_t *v1 = cla->value;
expr_t *v2 = clb->value;
ex_value_t *val1, *val2;
if (v1 == v2)
return 1;
if ((v1 && !v2) || (!v1 && v2))
return 0;
if (extract_type (v1) != extract_type (v2))
return 0;
val1 = get_value (v1);
val2 = get_value (v2);
if (val1->type != val2->type)
return 0;
return memcmp (&val1->v, &val2->v, sizeof (val1->v)) == 0;
}
struct expr_s *
case_label_expr (switch_block_t *switch_block, expr_t *value)
{
case_label_t *cl = malloc (sizeof (case_label_t));
SYS_CHECKMEM (cl);
if (value)
convert_name (value);
if (value && !is_constant (value)) {
error (value, "non-constant case value");
free (cl);
return 0;
}
if (!switch_block) {
error (value, "%s outside of switch", value ? "case" : "default");
free (cl);
return 0;
}
if (!switch_block->test)
internal_error (value, "broken switch block");
if (value) {
type_t *type = get_type (switch_block->test);
type_t *val_type = get_type (value);
if (!type)
return 0;
if (!type_assignable (type, get_type (value)))
return error (value, "type mismatch in case label");
if (is_integral (type) && is_integral (val_type)) {
value = new_int_expr (expr_int (value));
debug (value, "integeral label used in integral switch");
} else if (is_integral (type) && is_float (val_type)) {
warning (value, "float label used in integral switch");
value = new_int_expr (expr_float (value));
} else if (is_float (type) && is_integral (val_type)) {
debug (value, "integeral label used in float switch");
value = new_float_expr (expr_int (value));
} else if (is_float (type) && is_float (val_type)) {
value = new_float_expr (expr_float (value));
debug (value, "float label used in float switch");
}
}
cl->value = value;
if (Hash_FindElement (switch_block->labels, cl)) {
error (value, "duplicate %s", value ? "case" : "default");
free (cl);
return 0;
}
cl->label = new_label_expr ();
Hash_AddElement (switch_block->labels, cl);
return cl->label;
}
switch_block_t *
new_switch_block (void)
{
switch_block_t *switch_block = malloc (sizeof (switch_block_t));
SYS_CHECKMEM (switch_block);
switch_block->labels = Hash_NewTable (127, 0, 0, 0, 0);
Hash_SetHashCompare (switch_block->labels, get_hash, compare);
switch_block->test = 0;
return switch_block;
}
static __attribute__((pure)) int
label_compare (const void *_a, const void *_b)
{
const case_label_t **a = (const case_label_t **) _a;
const case_label_t **b = (const case_label_t **) _b;
const char *s1, *s2;
if (is_string_val ((*a)->value)) {
s1 = expr_string ((*a)->value);
if (!s1)
s1 = "";
s2 = expr_string ((*b)->value);
if (!s2)
s2 = "";
return strcmp (s1, s2);
} else if (is_float_val ((*a)->value)) {
return expr_float ((*a)->value) - expr_float ((*b)->value);
} else if (is_int_val ((*a)->value)) {
return expr_int ((*a)->value) - expr_int ((*b)->value);
}
internal_error (0, "in switch");
}
static case_node_t *
new_case_node (expr_t *low, expr_t *high)
{
case_node_t *node = malloc (sizeof (case_node_t));
if (!node)
Sys_Error ("out of memory");
node->low = low;
node->high = high;
if (low == high) {
node->labels = &node->_label;
node->_label = 0;
} else {
int size;
if (!is_int_val (low))
internal_error (low, "switch");
size = expr_int (high) - expr_int (low) + 1;
node->labels = calloc (size, sizeof (expr_t *));
}
node->left = node->right = 0;
return node;
}
static case_node_t *
balance_case_tree (case_node_t **nodes, int base, int count)
{
case_node_t *node;
int index = count / 2;
if (!count)
return 0;
node = nodes[base + index];
node->left = balance_case_tree (nodes, base, index);
base += index + 1;
count -= index + 1;
node->right = balance_case_tree (nodes, base, count);
return node;
}
static case_node_t *
build_case_tree (case_label_t **labels, int count, int range)
{
case_node_t **nodes;
int i, j, k;
int num_nodes = 0;
qsort (labels, count, sizeof (*labels), label_compare);
nodes = (case_node_t **) malloc (count * sizeof (case_node_t *));
if (!nodes)
Sys_Error ("out of memory");
if (range && is_int_val (labels[0]->value)) {
for (i = 0; i < count - 1; i = j, num_nodes++) {
for (j = i + 1; j < count; j++) {
if (expr_int (labels[j]->value)
- expr_int (labels[j - 1]->value) > 1)
break;
}
nodes[num_nodes] = new_case_node (labels[i]->value,
labels[j - 1]->value);
for (k = i; k < j; k++)
nodes[num_nodes]->labels[expr_int (labels[k]->value)
- expr_int (labels[i]->value)]
= labels[k]->label;
}
if (i < count) {
nodes[num_nodes] = new_case_node (labels[i]->value,
labels[i]->value);
nodes[num_nodes]->labels[0] = labels[i]->label;
num_nodes++;
}
} else {
for (i = 0; i < count; i++, num_nodes++) {
nodes[num_nodes] = new_case_node (labels[i]->value,
labels[i]->value);
nodes[num_nodes]->labels[0] = labels[i]->label;
}
}
return balance_case_tree (nodes, 0, num_nodes);
}
static void
build_switch (expr_t *sw, case_node_t *tree, int op, expr_t *sw_val,
expr_t *temp, expr_t *default_label)
{
expr_t *test;
expr_t *branch;
expr_t *high_label = default_label;
expr_t *low_label = default_label;
if (!tree) {
branch = goto_expr (default_label);
append_expr (sw, branch);
return;
}
if (tree->right) {
high_label = new_label_expr ();
}
if (tree->left) {
low_label = new_label_expr ();
}
test = binary_expr (op, sw_val, tree->low);
test = assign_expr (temp, test);
append_expr (sw, test);
if (tree->low == tree->high) {
branch = branch_expr (EQ, new_alias_expr (&type_int, temp),
tree->labels[0]);
append_expr (sw, branch);
if (tree->left) {
branch = branch_expr (GT, new_alias_expr (&type_int, temp),
high_label);
append_expr (sw, branch);
build_switch (sw, tree->left, op, sw_val, temp, default_label);
if (tree->right)
append_expr (sw, high_label);
}
if (tree->right || !tree->left) {
build_switch (sw, tree->right, op, sw_val, temp, default_label);
}
} else {
int low = expr_int (tree->low);
int high = expr_int (tree->high);
symbol_t *table_sym;
expr_t *table_expr;
expr_t *table_init;
const char *table_name = new_label_name ();
int i;
expr_t *range = binary_expr ('-', tree->high, tree->low);
expr_t *label;
table_init = new_compound_init ();
for (i = 0; i <= high - low; i++) {
tree->labels[i]->e.label.used++;
label = address_expr (tree->labels[i], 0);
append_element (table_init, new_element (label, 0));
}
table_sym = new_symbol_type (table_name,
array_type (&type_int,
high - low + 1));
initialize_def (table_sym, table_init, pr.near_data, sc_static,
current_symtab);
table_expr = new_symbol_expr (table_sym);
if (tree->left) {
branch = branch_expr (LT, temp, low_label);
append_expr (sw, branch);
}
test = binary_expr (GT, cast_expr (&type_uint, temp),
cast_expr (&type_uint, range));
branch = branch_expr (NE, test, high_label);
append_expr (sw, branch);
branch = jump_table_expr (table_expr, temp);
append_expr (sw, branch);
debug (sw, "switch using jump table");
if (tree->left) {
append_expr (sw, low_label);
build_switch (sw, tree->left, op, sw_val, temp, default_label);
}
if (tree->right) {
append_expr (sw, high_label);
build_switch (sw, tree->right, op, sw_val, temp, default_label);
}
}
}
static void
check_enum_switch (switch_block_t *switch_block)
{
case_label_t cl;
symbol_t *enum_val;
type_t *type = get_type (switch_block->test);
for (enum_val = type->t.symtab->symbols; enum_val;
enum_val = enum_val->next) {
cl.value = new_int_expr (enum_val->s.value->v.int_val);
if (!Hash_FindElement (switch_block->labels, &cl)) {
warning (switch_block->test,
"enumeration value `%s' not handled in switch",
enum_val->name);
}
}
}
struct expr_s *
switch_expr (switch_block_t *switch_block, expr_t *break_label,
expr_t *statements)
{
if (switch_block->test->type == ex_error) {
return switch_block->test;
}
case_label_t **labels, **l;
case_label_t _default_label;
case_label_t *default_label = &_default_label;
expr_t *sw = new_block_expr ();
type_t *type = get_type (switch_block->test);
expr_t *sw_val = new_temp_def_expr (type);
expr_t *default_expr;
int num_labels = 0;
int saved_line = pr.source_line;
pr_string_t saved_file = pr.source_file;
pr.source_line = sw_val->line = switch_block->test->line;
pr.source_file = sw_val->file = switch_block->test->file;
default_label->value = 0;
default_label = Hash_DelElement (switch_block->labels, default_label);
labels = (case_label_t **) Hash_GetList (switch_block->labels);
if (!default_label) {
default_label = &_default_label;
default_label->label = break_label;
if (options.warnings.enum_switch && is_enum (type))
check_enum_switch (switch_block);
}
append_expr (sw, assign_expr (sw_val, switch_block->test));
for (l = labels; *l; l++)
num_labels++;
if (options.code.progsversion == PROG_ID_VERSION
|| (!is_string(type) && !is_float(type) && !is_integral (type))
|| num_labels < 8) {
for (l = labels; *l; l++) {
expr_t *cmp = binary_expr (EQ, sw_val, (*l)->value);
expr_t *test = branch_expr (NE, test_expr (cmp),
(*l)->label);
append_expr (sw, test);
}
default_expr = goto_expr (default_label->label);
append_expr (sw, default_expr);
} else {
expr_t *temp;
int op;
case_node_t *case_tree;
if (is_string(type))
temp = new_temp_def_expr (&type_int);
else
temp = new_temp_def_expr (type);
case_tree = build_case_tree (labels, num_labels, is_integral (type));
op = '-';
if (type->type == ev_string)
op = NE;
build_switch (sw, case_tree, op, sw_val, temp, default_label->label);
}
pr.source_line = saved_line;
pr.source_file = saved_file;
append_expr (sw, statements);
append_expr (sw, break_label);
return sw;
}