diff --git a/py/compile.c b/py/compile.c
index bd1107ed7db6c422233481e3d8dc06a82e026161..83c2cfd6718fbbafd26e4ed3a578c88fe5497e46 100644
--- a/py/compile.c
+++ b/py/compile.c
@@ -88,7 +88,10 @@ py_parse_node_t fold_constants(py_parse_node_t pn) {
int arg0 = PY_PARSE_NODE_LEAF_ARG(pns->nodes[0]);
int arg1 = PY_PARSE_NODE_LEAF_ARG(pns->nodes[2]);
if (PY_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[1], PY_TOKEN_OP_DBL_LESS)) {
- pn = py_parse_node_new_leaf(PY_PARSE_NODE_SMALL_INT, arg0 << arg1); // XXX can overflow; enabled only to compare with CPython
+#if defined(MICROPY_EMIT_ENABLE_CPYTHON)
+ // can overflow; enabled only to compare with CPython
+ pn = py_parse_node_new_leaf(PY_PARSE_NODE_SMALL_INT, arg0 << arg1);
+#endif
} else if (PY_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[1], PY_TOKEN_OP_DBL_MORE)) {
pn = py_parse_node_new_leaf(PY_PARSE_NODE_SMALL_INT, arg0 >> arg1);
} else {
@@ -99,32 +102,43 @@ py_parse_node_t fold_constants(py_parse_node_t pn) {
break;
case PN_arith_expr:
- // XXX can overflow; enabled only to compare with CPython
+ // overflow checking here relies on SMALL_INT being strictly smaller than machine_int_t
if (n == 3 && PY_PARSE_NODE_IS_SMALL_INT(pns->nodes[0]) && PY_PARSE_NODE_IS_SMALL_INT(pns->nodes[2])) {
- int arg0 = PY_PARSE_NODE_LEAF_ARG(pns->nodes[0]);
- int arg1 = PY_PARSE_NODE_LEAF_ARG(pns->nodes[2]);
+ machine_int_t arg0 = PY_PARSE_NODE_LEAF_ARG(pns->nodes[0]);
+ machine_int_t arg1 = PY_PARSE_NODE_LEAF_ARG(pns->nodes[2]);
+ machine_int_t res;
if (PY_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[1], PY_TOKEN_OP_PLUS)) {
- pn = py_parse_node_new_leaf(PY_PARSE_NODE_SMALL_INT, arg0 + arg1);
+ res = arg0 + arg1;
} else if (PY_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[1], PY_TOKEN_OP_MINUS)) {
- pn = py_parse_node_new_leaf(PY_PARSE_NODE_SMALL_INT, arg0 - arg1);
+ res = arg0 - arg1;
} else {
// shouldn't happen
assert(0);
+ res = 0;
+ }
+ if (PY_FIT_SMALL_INT(res)) {
+ pn = py_parse_node_new_leaf(PY_PARSE_NODE_SMALL_INT, res);
}
}
break;
case PN_term:
- // XXX can overflow; enabled only to compare with CPython
if (n == 3 && PY_PARSE_NODE_IS_SMALL_INT(pns->nodes[0]) && PY_PARSE_NODE_IS_SMALL_INT(pns->nodes[2])) {
int arg0 = PY_PARSE_NODE_LEAF_ARG(pns->nodes[0]);
int arg1 = PY_PARSE_NODE_LEAF_ARG(pns->nodes[2]);
if (PY_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[1], PY_TOKEN_OP_STAR)) {
+#if defined(MICROPY_EMIT_ENABLE_CPYTHON)
+ // can overflow; enabled only to compare with CPython
pn = py_parse_node_new_leaf(PY_PARSE_NODE_SMALL_INT, arg0 * arg1);
+#endif
} else if (PY_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[1], PY_TOKEN_OP_SLASH)) {
; // pass
- //} else if (PY_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[1], PY_TOKEN_OP_)) {
- //pn = py_parse_node_new_leaf(PY_PARSE_NODE_SMALL_INT, arg0 - arg1);
+ } else if (PY_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[1], PY_TOKEN_OP_PERCENT)) {
+ // XXX implement this properly as Python's % operator acts differently to C's
+ pn = py_parse_node_new_leaf(PY_PARSE_NODE_SMALL_INT, arg0 % arg1);
+ } else if (PY_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[1], PY_TOKEN_OP_DBL_SLASH)) {
+ // XXX implement this properly as Python's // operator acts differently to C's
+ pn = py_parse_node_new_leaf(PY_PARSE_NODE_SMALL_INT, arg0 / arg1);
} else {
// shouldn't happen
assert(0);
@@ -148,8 +162,9 @@ py_parse_node_t fold_constants(py_parse_node_t pn) {
}
break;
+#if defined(MICROPY_EMIT_ENABLE_CPYTHON)
case PN_power:
- // XXX can overflow; enabled only to compare with CPython
+ // can overflow; enabled only to compare with CPython
if (PY_PARSE_NODE_IS_SMALL_INT(pns->nodes[0]) && PY_PARSE_NODE_IS_NULL(pns->nodes[1]) && !PY_PARSE_NODE_IS_NULL(pns->nodes[2])) {
py_parse_node_struct_t* pns2 = (py_parse_node_struct_t*)pns->nodes[2];
if (PY_PARSE_NODE_IS_SMALL_INT(pns2->nodes[0])) {
@@ -165,6 +180,7 @@ py_parse_node_t fold_constants(py_parse_node_t pn) {
}
}
break;
+#endif
}
}
diff --git a/py/parse.c b/py/parse.c
index 541c4eb3f549bf22f2193a11b81a7c0ac92f5966..7c45cd7d758a2fa4e0968ecf273641b6fdbd83d2 100644
--- a/py/parse.c
+++ b/py/parse.c
@@ -228,7 +228,7 @@ static void push_result_token(parser_t *parser, const py_lexer_t *lex) {
}
if (dec) {
pn = py_parse_node_new_leaf(PY_PARSE_NODE_DECIMAL, qstr_from_strn_copy(str, len));
- } else if (small_int && -0x800000 <= int_val && int_val <= 0x7fffff) { // XXX check this range formula!
+ } else if (small_int && PY_FIT_SMALL_INT(int_val)) {
pn = py_parse_node_new_leaf(PY_PARSE_NODE_SMALL_INT, int_val);
} else {
pn = py_parse_node_new_leaf(PY_PARSE_NODE_INTEGER, qstr_from_strn_copy(str, len));
diff --git a/py/parse.h b/py/parse.h
index 07d553c1418f9047fad7df8258c6309ebab11cde..a87ee08b901e95b3cb976a74dae0241215e17821 100644
--- a/py/parse.h
+++ b/py/parse.h
@@ -11,6 +11,11 @@ struct _py_lexer_t;
// - xxxx...1101: a token; bits 4 and above are py_token_kind_t
// - xxxx...xxx0: pointer to py_parse_node_struct_t
+// makes sure the top 5 bits of x are all cleared (positive number) or all set (negavite number)
+// these macros can probably go somewhere else because they are used more than just in the parser
+#define PY_UINT_HIGH_5_BITS (~((~((machine_uint_t)0)) >> 5))
+#define PY_FIT_SMALL_INT(x) (((((machine_uint_t)(x)) & PY_UINT_HIGH_5_BITS) == 0) || ((((machine_uint_t)(x)) & PY_UINT_HIGH_5_BITS) == PY_UINT_HIGH_5_BITS))
+
#define PY_PARSE_NODE_NULL (0)
#define PY_PARSE_NODE_ID (0x1)
#define PY_PARSE_NODE_SMALL_INT (0x3)