def float_mod(a, b):
y = b.number
mod = math_fmod(a.number, y) # Follows pypy implementation.
if mod: # I'm not sure why remainder and denominator
if (y < 0.0) != (mod < 0.0): # must have the same sign.
mod += y
else:
mod = copysign(0.0, y)
return Float(mod)
def descr_mod(self, space, w_rhs):
w_rhs = self._to_float(space, w_rhs)
if w_rhs is None:
return space.w_NotImplemented
x = self.floatval
y = w_rhs.floatval
if y == 0.0:
raise oefmt(space.w_ZeroDivisionError, "float modulo")
mod = math_fmod(x, y)
if mod:
# ensure the remainder has the same sign as the denominator
if (y < 0.0) != (mod < 0.0):
mod += y
else:
# the remainder is zero, and in the presence of signed zeroes
# fmod returns different results across platforms; ensure
# it has the same sign as the denominator; we'd like to do
# "mod = y * 0.0", but that may get optimized away
mod = copysign(0.0, y)
return W_FloatObject(mod)
def _divmod_w(space, w_float1, w_float2):
x = w_float1.floatval
y = w_float2.floatval
if y == 0.0:
raise oefmt(space.w_ZeroDivisionError, "float modulo")
mod = math_fmod(x, y)
# fmod is typically exact, so vx-mod is *mathematically* an
# exact multiple of wx. But this is fp arithmetic, and fp
# vx - mod is an approximation; the result is that div may
# not be an exact integral value after the division, although
# it will always be very close to one.
div = (x - mod) / y
if (mod):
# ensure the remainder has the same sign as the denominator
if ((y < 0.0) != (mod < 0.0)):
mod += y
div -= 1.0
else:
# the remainder is zero, and in the presence of signed zeroes
# fmod returns different results across platforms; ensure
# it has the same sign as the denominator; we'd like to do
# "mod = wx * 0.0", but that may get optimized away
mod *= mod # hide "mod = +0" from optimizer
if y < 0.0:
mod = -mod
# snap quotient to nearest integral value
if div:
floordiv = math.floor(div)
if (div - floordiv > 0.5):
floordiv += 1.0
else:
# div is zero - get the same sign as the true quotient
div *= div # hide "div = +0" from optimizers
floordiv = div * x / y # zero w/ sign of vx/wx
return [W_FloatObject(floordiv), W_FloatObject(mod)]
