py: Add "default" to switches to allow better code flow analysis.

This helps compiler produce smaller code.  Saves 124 bytes on stmhal and
bare-arm.
This commit is contained in:
Damien George 2015-01-14 21:32:42 +00:00
parent 65ef6b768c
commit d2d64f00fb
7 changed files with 19 additions and 26 deletions

View File

@ -860,6 +860,7 @@ STATIC void c_assign(compiler_t *comp, mp_parse_node_t pn, assign_kind_t assign_
EMIT_ARG(store_id, arg);
break;
case ASSIGN_AUG_LOAD:
default:
EMIT_ARG(load_id, arg);
break;
}
@ -2185,8 +2186,7 @@ STATIC void compile_expr_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) {
case MP_TOKEN_DEL_DBL_SLASH_EQUAL: op = MP_BINARY_OP_INPLACE_FLOOR_DIVIDE; break;
case MP_TOKEN_DEL_SLASH_EQUAL: op = MP_BINARY_OP_INPLACE_TRUE_DIVIDE; break;
case MP_TOKEN_DEL_PERCENT_EQUAL: op = MP_BINARY_OP_INPLACE_MODULO; break;
case MP_TOKEN_DEL_DBL_STAR_EQUAL: op = MP_BINARY_OP_INPLACE_POWER; break;
default: assert(0); op = MP_BINARY_OP_INPLACE_OR; // shouldn't happen
case MP_TOKEN_DEL_DBL_STAR_EQUAL: default: op = MP_BINARY_OP_INPLACE_POWER; break;
}
EMIT_ARG(binary_op, op);
c_assign(comp, pns->nodes[0], ASSIGN_AUG_STORE); // lhs store for aug assign
@ -2350,8 +2350,7 @@ STATIC void compile_comparison(compiler_t *comp, mp_parse_node_struct_t *pns) {
case MP_TOKEN_OP_LESS_EQUAL: op = MP_BINARY_OP_LESS_EQUAL; break;
case MP_TOKEN_OP_MORE_EQUAL: op = MP_BINARY_OP_MORE_EQUAL; break;
case MP_TOKEN_OP_NOT_EQUAL: op = MP_BINARY_OP_NOT_EQUAL; break;
case MP_TOKEN_KW_IN: op = MP_BINARY_OP_IN; break;
default: assert(0); op = MP_BINARY_OP_LESS; // shouldn't happen
case MP_TOKEN_KW_IN: default: op = MP_BINARY_OP_IN; break;
}
EMIT_ARG(binary_op, op);
} else if (MP_PARSE_NODE_IS_STRUCT(pns->nodes[i])) {
@ -2982,7 +2981,7 @@ STATIC void compile_node(compiler_t *comp, mp_parse_node_t pn) {
case MP_PARSE_NODE_DECIMAL: EMIT_ARG(load_const_dec, arg); break;
case MP_PARSE_NODE_STRING: EMIT_ARG(load_const_str, arg, false); break;
case MP_PARSE_NODE_BYTES: EMIT_ARG(load_const_str, arg, true); break;
case MP_PARSE_NODE_TOKEN:
case MP_PARSE_NODE_TOKEN: default:
if (arg == MP_TOKEN_NEWLINE) {
// this can occur when file_input lets through a NEWLINE (eg if file starts with a newline)
// or when single_input lets through a NEWLINE (user enters a blank line)
@ -2991,7 +2990,6 @@ STATIC void compile_node(compiler_t *comp, mp_parse_node_t pn) {
EMIT_ARG(load_const_tok, arg);
}
break;
default: assert(0);
}
} else {
mp_parse_node_struct_t *pns = (mp_parse_node_struct_t*)pn;

View File

@ -454,8 +454,9 @@ STATIC void emit_bc_load_const_tok(emit_t *emit, mp_token_kind_t tok) {
case MP_TOKEN_KW_FALSE: emit_write_bytecode_byte(emit, MP_BC_LOAD_CONST_FALSE); break;
case MP_TOKEN_KW_NONE: emit_write_bytecode_byte(emit, MP_BC_LOAD_CONST_NONE); break;
case MP_TOKEN_KW_TRUE: emit_write_bytecode_byte(emit, MP_BC_LOAD_CONST_TRUE); break;
no_other_choice:
case MP_TOKEN_ELLIPSIS: emit_write_bytecode_byte(emit, MP_BC_LOAD_CONST_ELLIPSIS); break;
default: assert(0);
default: assert(0); goto no_other_choice; // to help flow control analysis
}
}

View File

@ -110,6 +110,7 @@ mp_obj_t mp_make_function_from_raw_code(mp_raw_code_t *rc, mp_obj_t def_args, mp
mp_obj_t fun;
switch (rc->kind) {
case MP_CODE_BYTECODE:
no_other_choice:
fun = mp_obj_new_fun_bc(rc->scope_flags, rc->n_pos_args, rc->n_kwonly_args, def_args, def_kw_args, rc->u_byte.code);
break;
#if MICROPY_EMIT_NATIVE
@ -128,7 +129,7 @@ mp_obj_t mp_make_function_from_raw_code(mp_raw_code_t *rc, mp_obj_t def_args, mp
default:
// raw code was never set (this should not happen)
assert(0);
return mp_const_none;
goto no_other_choice; // to help flow control analysis
}
// check for generator functions and if so wrap in generator object

View File

@ -415,7 +415,7 @@ STATIC mp_obj_t dict_view_it_iternext(mp_obj_t self_in) {
} else {
switch (self->kind) {
case MP_DICT_VIEW_ITEMS:
{
default: {
mp_obj_t items[] = {next->key, next->value};
return mp_obj_new_tuple(2, items);
}
@ -423,9 +423,6 @@ STATIC mp_obj_t dict_view_it_iternext(mp_obj_t self_in) {
return next->key;
case MP_DICT_VIEW_VALUES:
return next->value;
default:
assert(0); /* can't happen */
return mp_const_none;
}
}
}

View File

@ -83,11 +83,8 @@ STATIC mp_obj_t fun_builtin_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n
return ((mp_fun_2_t)self->fun)(args[0], args[1]);
case 3:
return ((mp_fun_3_t)self->fun)(args[0], args[1], args[2]);
default:
assert(0);
return mp_const_none;
return ((mp_fun_3_t)self->fun)(args[0], args[1], args[2]);
}
} else {

View File

@ -120,6 +120,7 @@ mp_vm_return_kind_t mp_obj_gen_resume(mp_obj_t self_in, mp_obj_t send_value, mp_
switch (ret_kind) {
case MP_VM_RETURN_NORMAL:
default:
// Explicitly mark generator as completed. If we don't do this,
// subsequent next() may re-execute statements after last yield
// again and again, leading to side effects.
@ -137,11 +138,6 @@ mp_vm_return_kind_t mp_obj_gen_resume(mp_obj_t self_in, mp_obj_t send_value, mp_
self->code_state.ip = 0;
*ret_val = self->code_state.state[self->code_state.n_state - 1];
break;
default:
assert(0);
*ret_val = mp_const_none;
break;
}
return ret_kind;
@ -151,6 +147,7 @@ STATIC mp_obj_t gen_resume_and_raise(mp_obj_t self_in, mp_obj_t send_value, mp_o
mp_obj_t ret;
switch (mp_obj_gen_resume(self_in, send_value, throw_value, &ret)) {
case MP_VM_RETURN_NORMAL:
default:
// Optimize return w/o value in case generator is used in for loop
if (ret == mp_const_none || ret == MP_OBJ_STOP_ITERATION) {
return MP_OBJ_STOP_ITERATION;
@ -173,10 +170,6 @@ STATIC mp_obj_t gen_resume_and_raise(mp_obj_t self_in, mp_obj_t send_value, mp_o
} else {
nlr_raise(ret);
}
default:
assert(0);
return mp_const_none;
}
}

View File

@ -456,11 +456,13 @@ mp_parse_node_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind, mp_p
}
break;
case RULE_ARG_RULE:
rule_or_no_other_choice:
push_rule(&parser, rule_src_line, rule, i + 1); // save this or-rule
push_rule_from_arg(&parser, rule->arg[i]); // push child of or-rule
goto next_rule;
default:
assert(0);
goto rule_or_no_other_choice; // to help flow control analysis
}
}
if ((rule->arg[i] & RULE_ARG_KIND_MASK) == RULE_ARG_TOK) {
@ -520,14 +522,16 @@ mp_parse_node_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind, mp_p
}
}
break;
}
}
case RULE_ARG_RULE:
case RULE_ARG_OPT_RULE:
rule_and_no_other_choice:
push_rule(&parser, rule_src_line, rule, i + 1); // save this and-rule
push_rule_from_arg(&parser, rule->arg[i]); // push child of and-rule
goto next_rule;
default:
assert(0);
goto rule_and_no_other_choice; // to help flow control analysis
}
}
@ -674,11 +678,13 @@ mp_parse_node_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind, mp_p
}
break;
case RULE_ARG_RULE:
rule_list_no_other_choice:
push_rule(&parser, rule_src_line, rule, i + 1); // save this list-rule
push_rule_from_arg(&parser, arg); // push child of list-rule
goto next_rule;
default:
assert(0);
goto rule_list_no_other_choice; // to help flow control analysis
}
}
}