py/objint: Do not use fpclassify.

For combinations of certain versions of glibc and gcc the definition of
fpclassify always takes float as argument instead of adapting itself to
float/double/long double as required by the C99 standard.  At the time of
writing this happens for instance for glibc 2.27 with gcc 7.5.0 when
compiled with -Os and glibc 3.0.7 with gcc 9.3.0.  When calling fpclassify
with double as argument, as in objint.c, this results in an implicit
narrowing conversion which is not really correct plus results in a warning
when compiled with -Wfloat-conversion.  So fix this by spelling out the
logic manually.
This commit is contained in:
stijn 2020-04-06 10:44:48 +02:00 committed by Damien George
parent 70affd9ba2
commit f31f9a8b70
3 changed files with 11 additions and 5 deletions

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@ -135,11 +135,15 @@ STATIC mp_fp_as_int_class_t mp_classify_fp_as_int(mp_float_t val) {
#undef MP_FLOAT_EXP_SHIFT_I32 #undef MP_FLOAT_EXP_SHIFT_I32
mp_obj_t mp_obj_new_int_from_float(mp_float_t val) { mp_obj_t mp_obj_new_int_from_float(mp_float_t val) {
int cl = fpclassify(val); mp_float_union_t u = {val};
if (cl == FP_INFINITE) { // IEEE-754: if biased exponent is all 1 bits...
if (u.p.exp == ((1 << MP_FLOAT_EXP_BITS) - 1)) {
// ...then number is Inf (positive or negative) if fraction is 0, else NaN.
if (u.p.frc == 0) {
mp_raise_msg(&mp_type_OverflowError, MP_ERROR_TEXT("can't convert inf to int")); mp_raise_msg(&mp_type_OverflowError, MP_ERROR_TEXT("can't convert inf to int"));
} else if (cl == FP_NAN) { } else {
mp_raise_ValueError(MP_ERROR_TEXT("can't convert NaN to int")); mp_raise_ValueError(MP_ERROR_TEXT("can't convert NaN to int"));
}
} else { } else {
mp_fp_as_int_class_t icl = mp_classify_fp_as_int(val); mp_fp_as_int_class_t icl = mp_classify_fp_as_int(val);
if (icl == MP_FP_CLASS_FIT_SMALLINT) { if (icl == MP_FP_CLASS_FIT_SMALLINT) {

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@ -96,6 +96,7 @@ else:
fp2int_test(1.9999999999999981 * 2.0 ** 1023.0, "large pos", False) fp2int_test(1.9999999999999981 * 2.0 ** 1023.0, "large pos", False)
fp2int_test(float("inf"), "inf test", True) fp2int_test(float("inf"), "inf test", True)
fp2int_test(float("-inf"), "inf test", True)
fp2int_test(float("nan"), "NaN test", True) fp2int_test(float("nan"), "NaN test", True)
# test numbers < 1 (this used to fail; see issue #1044) # test numbers < 1 (this used to fail; see issue #1044)

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@ -93,6 +93,7 @@ else:
fp2int_test(1.999999879 * 2.0 ** 126.0, "large pos", False) fp2int_test(1.999999879 * 2.0 ** 126.0, "large pos", False)
fp2int_test(float("inf"), "inf test", True) fp2int_test(float("inf"), "inf test", True)
fp2int_test(float("-inf"), "inf test", True)
fp2int_test(float("nan"), "NaN test", True) fp2int_test(float("nan"), "NaN test", True)
# test numbers < 1 (this used to fail; see issue #1044) # test numbers < 1 (this used to fail; see issue #1044)