qf/quakeforge
0
0
Fork 0
mirror of https://git.code.sf.net/p/quake/quakeforge synced 2025-01-31 13:10:34 +00:00
Code Issues Projects Releases Packages Wiki Activity

[qfcc] Break out pointer addressing

Browse source 
This allows the code handling simple pointer dereferences to recurse
along an alias chain that resulted from casting between different
pointer types (such chains could probably be eliminated by replacing the
type in the original pointer expression, but it wasn't worth it at this
stage).
This commit is contained in:
Bill Currie 2022-01-28 15:37:08 +09:00
parent d28507eacf
commit e298f0d993
1 changed files with 54 additions and 42 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

96
tools/qfcc/source/statements.c
View file

@ -1256,6 +1256,58 @@ statement_branch (sblock_t *sblock, expr_t *e)
return sblock->next;
}
static sblock_t *
ptr_addressing_mode (sblock_t *sblock, expr_t *ref,
operand_t **base, operand_t **offset, pr_ushort_t *mode)
{
if (!is_ptr (get_type (ref))) {
internal_error (ref, "expected pointer in ref");
}
if (ref->type != ex_alias || ref->e.alias.offset) {
// probably just a pointer
sblock = statement_subexpr (sblock, ref, base);
*offset = short_operand (0, ref);
*mode = 2; // mode C: ptr + constant index
} else if (is_ptr (get_type (ref->e.alias.expr))) {
// cast of one pointer type to another
return ptr_addressing_mode (sblock, ref->e.alias.expr, base, offset,
mode);
} else {
// alias with no offset
if (!is_integral (get_type (ref->e.alias.expr))) {
internal_error (ref, "expected integer expr in ref");
}
expr_t *intptr = ref->e.alias.expr;
if (intptr->type != ex_expr
|| (intptr->e.expr.op != '+'
&& intptr->e.expr.op != '-')) {
// treat ref as simple pointer
sblock = statement_subexpr (sblock, ref, base);
*offset = short_operand (0, ref);
*mode = 2; // mode C: ptr + constant index
} else {
expr_t *ptr = intptr->e.expr.e1;
expr_t *offs = intptr->e.expr.e2;
int const_offs;
// move the +/- to the offset
offs = unary_expr (intptr->e.expr.op, offs);
// make the base a pointer again
ptr = new_alias_expr (ref->e.alias.type, ptr);
sblock = statement_subexpr (sblock, ptr, base);
if (is_constant (offs)
&& (const_offs = expr_int (offs)) < 32768
&& const_offs >= -32768) {
*mode = 2;
*offset = short_operand (const_offs, ref);
} else {
*mode = 3;
sblock = statement_subexpr (sblock, offs, offset);
}
}
}
return sblock;
}
static sblock_t *
addressing_mode (sblock_t *sblock, expr_t *ref,
operand_t **base, operand_t **offset, pr_ushort_t *mode)
@ -1266,48 +1318,8 @@ addressing_mode (sblock_t *sblock, expr_t *ref,
if (ref->type == ex_expr) {
internal_error (ref, "not implemented");
} else if (ref->type == ex_uexpr) {
ref = ref->e.expr.e1;
if (!is_ptr (get_type (ref))) {
internal_error (ref, "expected pointer in ref");
}
if (ref->type != ex_alias || ref->e.alias.offset) {
// probably just a pointer
sblock = statement_subexpr (sblock, ref, base);
*offset = short_operand (0, ref);
*mode = 2; // mode C: ptr + constant index
} else {
// alias with no offset
if (!is_integral (get_type (ref->e.alias.expr))) {
internal_error (ref, "expected integer expr in ref");
}
expr_t *intptr = ref->e.alias.expr;
if (intptr->type != ex_expr
|| (intptr->e.expr.op != '+'
&& intptr->e.expr.op != '-')) {
// treat ref as simple pointer
sblock = statement_subexpr (sblock, ref, base);
*offset = short_operand (0, ref);
*mode = 2; // mode C: ptr + constant index
} else {
expr_t *ptr = intptr->e.expr.e1;
expr_t *offs = intptr->e.expr.e2;
int const_offs;
// move the +/- to the offset
offs = unary_expr (intptr->e.expr.op, offs);
// make the base a pointer again
ptr = new_alias_expr (ref->e.alias.type, ptr);
sblock = statement_subexpr (sblock, ptr, base);
if (is_constant (offs)
&& (const_offs = expr_int (offs)) < 32768
&& const_offs >= -32768) {
*mode = 2;
*offset = short_operand (const_offs, ref);
} else {
*mode = 3;
sblock = statement_subexpr (sblock, offs, offset);
}
}
}
sblock = ptr_addressing_mode (sblock, ref->e.expr.e1, base, offset,
mode);
} else {
internal_error (ref, "unexpected expression type for indirect: %s",
expr_names[ref->type]);