py: Partially fix float to int conversion.

pfalcon · pfalcon · commit 12033df511a5 · 2014-12-30T00:22:50.000+02:00
This fixes conversion when float type has more mantissa bits than small int,
and float value has small exponent. This is for example the case of 32-bit
platform using doubles, and converting value of time.time(). Conversion of
floats with larg exponnet is still not handled correctly.
diff --git a/py/obj.h b/py/obj.h
@@ -399,6 +399,7 @@ mp_obj_t mp_obj_new_int_from_uint(mp_uint_t value);
 mp_obj_t mp_obj_new_int_from_str_len(const char **str, mp_uint_t len, bool neg, mp_uint_t base);
 mp_obj_t mp_obj_new_int_from_ll(long long val); // this must return a multi-precision integer object (or raise an overflow exception)
 mp_obj_t mp_obj_new_int_from_ull(unsigned long long val); // this must return a multi-precision integer object (or raise an overflow exception)
+mp_obj_t mp_obj_new_int_from_float(mp_float_t val);
 mp_obj_t mp_obj_new_str(const char* data, mp_uint_t len, bool make_qstr_if_not_already);
 mp_obj_t mp_obj_new_bytes(const byte* data, mp_uint_t len);
 mp_obj_t mp_obj_new_bytearray(mp_uint_t n, void *items);
diff --git a/py/objint.c b/py/objint.c
@@ -65,7 +65,7 @@ STATIC mp_obj_t mp_obj_int_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_
                 return mp_parse_num_integer(s, l, 0);
 #if MICROPY_PY_BUILTINS_FLOAT
             } else if (MP_OBJ_IS_TYPE(args[0], &mp_type_float)) {
-                return MP_OBJ_NEW_SMALL_INT((MICROPY_FLOAT_C_FUN(trunc)(mp_obj_float_get(args[0]))));
+                return mp_obj_new_int_from_float(mp_obj_float_get(args[0]));
 #endif
             } else {
                 // try to convert to small int (eg from bool)
diff --git a/py/objint_longlong.c b/py/objint_longlong.c
@@ -40,6 +40,10 @@
 #include "runtime0.h"
 #include "runtime.h"
 
+#if MICROPY_PY_BUILTINS_FLOAT
+#include <math.h>
+#endif
+
 #if MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_LONGLONG
 
 // Python3 no longer has "l" suffix for long ints. We allow to use it
@@ -187,6 +191,14 @@ mp_obj_t mp_obj_new_int_from_ull(unsigned long long val) {
     return o;
 }
 
+#if MICROPY_PY_BUILTINS_FLOAT
+mp_obj_t mp_obj_new_int_from_float(mp_float_t val) {
+    // TODO raise an exception if the unsigned long long won't fit
+    long long i = MICROPY_FLOAT_C_FUN(trunc)(val);
+    return mp_obj_new_int_from_ll(i);
+}
+#endif
+
 mp_obj_t mp_obj_new_int_from_str_len(const char **str, mp_uint_t len, bool neg, mp_uint_t base) {
     // TODO this does not honor the given length of the string, but it all cases it should anyway be null terminated
     // TODO check overflow
diff --git a/py/objint_mpz.c b/py/objint_mpz.c
@@ -41,6 +41,10 @@
 #include "runtime0.h"
 #include "runtime.h"
 
+#if MICROPY_PY_BUILTINS_FLOAT
+#include <math.h>
+#endif
+
 #if MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_MPZ
 
 #if MICROPY_PY_SYS_MAXSIZE
@@ -298,6 +302,14 @@ mp_obj_t mp_obj_new_int_from_uint(mp_uint_t value) {
     return mp_obj_new_int_from_ll(value);
 }
 
+#if MICROPY_PY_BUILTINS_FLOAT
+mp_obj_t mp_obj_new_int_from_float(mp_float_t val) {
+    // TODO: This doesn't handle numbers with large exponent
+    long long i = MICROPY_FLOAT_C_FUN(trunc)(val);
+    return mp_obj_new_int_from_ll(i);
+}
+#endif
+
 mp_obj_t mp_obj_new_int_from_str_len(const char **str, mp_uint_t len, bool neg, mp_uint_t base) {
     mp_obj_int_t *o = mp_obj_int_new_mpz();
     mp_uint_t n = mpz_set_from_str(&o->mpz, *str, len, neg, base);
diff --git a/tests/float/float2int.py b/tests/float/float2int.py
@@ -0,0 +1,5 @@
+# This case occurs with time.time() values
+print(int(1418774543.))
+
+# TODO: General case with large exponent
+#print(int(2.**100))
