py: Add compiler optimisation for conditions in parenthesis.

Optimises:
    if () -> if False
    if (x,...) -> if True
    if (a and b) -> if a and b
This commit is contained in:
Damien George 2014-08-29 20:04:01 +01:00
parent 15d2fe8da4
commit eb4e18f057
1 changed files with 17 additions and 0 deletions

View File

@ -713,6 +713,23 @@ STATIC void c_if_cond(compiler_t *comp, mp_parse_node_t pn, bool jump_if, int la
} else if (MP_PARSE_NODE_STRUCT_KIND(pns) == PN_not_test_2) {
c_if_cond(comp, pns->nodes[0], !jump_if, label);
return;
} else if (MP_PARSE_NODE_STRUCT_KIND(pns) == PN_atom_paren) {
// cond is something in parenthesis
if (MP_PARSE_NODE_IS_NULL(pns->nodes[0])) {
// empty tuple, acts as false for the condition
if (jump_if == false) {
EMIT_ARG(jump, label);
}
} else if (MP_PARSE_NODE_IS_STRUCT_KIND(pns->nodes[0], PN_testlist_comp)) {
// non-empty tuple, acts as true for the condition
if (jump_if == true) {
EMIT_ARG(jump, label);
}
} else {
// parenthesis around 1 item, is just that item
c_if_cond(comp, pns->nodes[0], jump_if, label);
}
return;
}
}