From 2e4dda3c2072c4de15ac8d51ddb471b9c3833db7 Mon Sep 17 00:00:00 2001 From: Damien George Date: Thu, 23 Feb 2023 10:53:39 +1100 Subject: [PATCH] py/modmath: Fix two-argument math function domain check. Prior to this fix, pow(1.5, inf) and pow(0.5, -inf) (among other things) would incorrectly raise a ValueError, because the result is inf with the first argument being finite. This commit fixes this by allowing the result to be infinite if the first or second (or both) argument is infinite. This fix doesn't affect the other three math functions that have two arguments: - atan2 never returns inf, so always fails isinf(ans) - copysign returns inf only if the first argument x is inf, so will never reach the isinf(y) check - fmod never returns inf, so always fails isinf(ans) Signed-off-by: Damien George --- py/modmath.c | 2 +- tests/float/math_domain.py | 21 ++++++++++++++++++++- 2 files changed, 21 insertions(+), 2 deletions(-) diff --git a/py/modmath.c b/py/modmath.c index 72b5dde517..861a23b48b 100644 --- a/py/modmath.c +++ b/py/modmath.c @@ -54,7 +54,7 @@ STATIC mp_obj_t math_generic_2(mp_obj_t x_obj, mp_obj_t y_obj, mp_float_t (*f)(m mp_float_t x = mp_obj_get_float(x_obj); mp_float_t y = mp_obj_get_float(y_obj); mp_float_t ans = f(x, y); - if ((isnan(ans) && !isnan(x) && !isnan(y)) || (isinf(ans) && !isinf(x))) { + if ((isnan(ans) && !isnan(x) && !isnan(y)) || (isinf(ans) && !isinf(x) && !isinf(y))) { math_error(); } return mp_obj_new_float(ans); diff --git a/tests/float/math_domain.py b/tests/float/math_domain.py index 063d509b59..606a655284 100644 --- a/tests/float/math_domain.py +++ b/tests/float/math_domain.py @@ -39,7 +39,26 @@ for name, f, args in ( # double argument functions for name, f, args in ( - ("pow", math.pow, ((0, 2), (-1, 2), (0, -1), (-1, 2.3), (nan, 0), (1, nan))), + ( + "pow", + math.pow, + ( + (0, 2), + (-1, 2), + (0, -1), + (-1, 2.3), + (0.5, inf), + (-0.5, inf), + (0.5, -inf), + (-0.5, -inf), + (1.5, inf), + (-1.5, inf), + (1.5, -inf), + (-1.5, -inf), + (nan, 0), + (1, nan), + ), + ), ("log", math.log, ()), ("fmod", math.fmod, ((1.2, inf), (1.2, -inf), (1.2, 0), (inf, 1.2))), ("atan2", math.atan2, ((0, 0), (-inf, inf), (-inf, -inf), (inf, -inf))),