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#ifndef BDL_COMPILER_H
#define BDL_COMPILER_H
#define PRELUDE_FILE "src/x86_64/prelude.asm"
#define POSTLUDE_FILE "src/x86_64/postlude.asm"
#define NIL_VAL 1
#define BOOL_MASK 3
#define BOOL_TAG 3
#define BOOL_SHIFT 2
#define FIXNUM_MASK 1
#define FIXNUM_TAG 0
#define FIXNUM_SHIFT 1
void compile_object(Object *obj);
void compile_fixnum(Object *obj);
void compile_proc_call(Object *obj);
void compile(Root *roots);
void
emit_file(char *file_name) {
FILE *file = fopen(file_name, "r");
if (!file) {
fprintf(stderr, "error: couldn't open input file: %s\n", file_name);
exit(EXIT_FAILURE);
}
char buf[1024];
size_t n = 0;
while ((n = fread(&buf, 1, 1024, file)) > 0) {
fwrite(buf, 1, n, stdout);
}
}
void
compile_fixnum(Object *obj) {
printf(" ;; --> compile_fixnum\n");
printf(" mov rax, %ld\n", (obj->fixnum << FIXNUM_SHIFT) | FIXNUM_TAG);
printf(" push rax\n");
printf(" ;; <-- compile_fixnum\n");
}
void
compile_boolean(Object *obj) {
printf(" ;; --> compile_boolean\n");
int is_true = obj->type == OBJ_TYPE_TRUE;
printf(" mov rax, %d\n", (is_true << BOOL_SHIFT) | BOOL_TAG);
printf(" push rax\n");
printf(" ;; <-- compile_boolean\n");
}
void
compile_nil(void) {
printf(" ;; --> compile_nil\n");
printf(" mov rax, %d\n", NIL_VAL);
printf(" push rax\n");
printf(" ;; <-- compile_nil\n");
}
typedef enum OpType {
// Arithmetic.
OP_ADD,
OP_SUB,
OP_MUL,
OP_DIV,
OP_MOD,
// Type predicates.
OP_IS_NIL,
OP_IS_ZERO,
OP_IS_BOOL,
OP_IS_FIXNUM,
// TODO: etc.
} OpType;
void
arithmetic_op(OpType type) {
printf(" ;; --> arithmetic_op\n");
printf(" pop rcx\n");
printf(" pop rax\n");
switch (type) {
case OP_ADD: { printf(" add rax, rcx\n"); } break;
case OP_SUB: { printf(" sub rax, rcx\n"); } break;
case OP_MUL: {
printf(" sar rax, %d\n", FIXNUM_SHIFT);
printf(" sar rcx, %d\n", FIXNUM_SHIFT);
printf(" mul rcx\n");
printf(" sal rax, %d\n", FIXNUM_SHIFT);
} break;
case OP_DIV: {
printf(" sar rax, %d\n", FIXNUM_SHIFT);
printf(" sar rcx, %d\n", FIXNUM_SHIFT);
printf(" mov rdx, 0\n");
printf(" div rcx\n");
printf(" sal rax, %d\n", FIXNUM_SHIFT);
} break;
case OP_MOD: {
printf(" sar rax, %d\n", FIXNUM_SHIFT);
printf(" sar rcx, %d\n", FIXNUM_SHIFT);
printf(" mov rdx, 0\n");
printf(" div rcx\n");
printf(" mov rax, rdx\n");
printf(" sal rax, %d\n", FIXNUM_SHIFT);
} break;
default: break;
}
printf(" push rax\n");
printf(" ;; <-- arithmetic_op\n");
}
typedef void (CompileProc)(OpType, Object*);
void
compile_type_predicate(OpType op, Object* args) {
printf(" ;; --> compile_type_predicate\n");
compile_object(args->head);
printf(" pop rax\n");
switch (op) {
case OP_IS_NIL: {
printf(" cmp rax, %d\n", NIL_VAL);
} break;
case OP_IS_ZERO: {
printf(" cmp rax, 0\n");
} break;
case OP_IS_BOOL: {
printf(" and rax, %d\n", BOOL_MASK);
printf(" cmp rax, %d\n", BOOL_TAG);
} break;
case OP_IS_FIXNUM: {
printf(" and rax, %d\n", FIXNUM_MASK);
printf(" cmp rax, %d\n", FIXNUM_TAG);
} break;
default: break;
}
printf(" mov rax, 0\n");
printf(" sete al\n");
printf(" sal rax, %d\n", BOOL_SHIFT);
printf(" or rax, %d\n", BOOL_TAG);
printf(" push rax\n");
printf(" ;; <-- compile_type_predicate\n");
}
void
compile_arithmetic_list(OpType op, Object* args) {
printf(" ;; --> compile_arithmetic_list\n");
compile_object(args->head);
args = args->tail;
while (args != NULL) {
compile_object(args->head);
args = args->tail;
arithmetic_op(op);
}
printf(" ;; <-- compile_arithmetic_list\n");
}
void
compile_proc_call(Object *obj) {
// TODO: Probably we want to use a hash table for these lookups that is
// initialized at the start of the compilation procedure.
if (sv_equal(&obj->head->text, &STRING("+"))) {
compile_arithmetic_list(OP_ADD, obj->tail);
}
if (sv_equal(&obj->head->text, &STRING("-"))) {
compile_arithmetic_list(OP_SUB, obj->tail);
}
if (sv_equal(&obj->head->text, &STRING("*"))) {
compile_arithmetic_list(OP_MUL, obj->tail);
}
if (sv_equal(&obj->head->text, &STRING("/"))) {
compile_arithmetic_list(OP_DIV, obj->tail);
}
if (sv_equal(&obj->head->text, &STRING("%"))) {
compile_arithmetic_list(OP_MOD, obj->tail);
}
if (sv_equal(&obj->head->text, &STRING("nil?"))) {
compile_type_predicate(OP_IS_NIL, obj->tail);
}
if (sv_equal(&obj->head->text, &STRING("zero?"))) {
compile_type_predicate(OP_IS_ZERO, obj->tail);
}
if (sv_equal(&obj->head->text, &STRING("fixnum?"))) {
compile_type_predicate(OP_IS_FIXNUM, obj->tail);
}
if (sv_equal(&obj->head->text, &STRING("bool?"))) {
compile_type_predicate(OP_IS_BOOL, obj->tail);
}
}
void
compile_object(Object *obj) {
switch (obj->type) {
case OBJ_TYPE_NIL: { compile_nil(); } break;
case OBJ_TYPE_TRUE:
case OBJ_TYPE_FALSE: { compile_boolean(obj); } break;
case OBJ_TYPE_FIXNUM: { compile_fixnum(obj); } break;
case OBJ_TYPE_PAIR: { compile_proc_call(obj); } break;
default: break;
}
}
void
compile(Root *roots) {
emit_file(PRELUDE_FILE);
for (size_t i = 0; i < array_size(roots); i++) {
Object *root = roots[i];
compile_object(root);
// OBJ_PRINT(root);
}
emit_file(POSTLUDE_FILE);
}
#endif // BDL_COMPILER_H
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