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Fix bug atan2

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This commit is contained in:
Rasmus Munk Larsen 2022-10-12 23:49:32 +00:00
parent 14c847dc0e
commit 3bb6a48d8c
1 changed files with 24 additions and 18 deletions
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40
Eigen/src/Core/functors/BinaryFunctors.h
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@ -518,22 +518,26 @@ struct scalar_atan2_op {
return static_cast<Scalar>(atan2(y, x));
}
template <typename Packet>
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE std::enable_if_t<is_same<LhsScalar,RhsScalar>::value, Packet> packetOp(const Packet& y,
const Packet& x) const {
EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE
std::enable_if_t<is_same<LhsScalar, RhsScalar>::value, Packet>
packetOp(const Packet& y, const Packet& x) const {
// See https://en.cppreference.com/w/cpp/numeric/math/atan2
// for how corner cases are supposed to be handled according to the
// IEEE floating-point standard (IEC 60559).
const Packet kSignMask = pset1<Packet>(-Scalar(0.0));
const Packet kSignMask = pset1<Packet>(-Scalar(0));
const Packet kPi = pset1<Packet>(Scalar(EIGEN_PI));
const Packet kPiO2 = pset1<Packet>(Scalar(EIGEN_PI / 2));
const Packet kPiO4 = pset1<Packet>(Scalar(EIGEN_PI / 4));
constexpr Scalar k3PiO4f = Scalar(3.0 * (EIGEN_PI / 4));
const Packet k3PiO4 = pset1<Packet>(k3PiO4f);
Packet x_neg = pcmp_lt(x, pzero(x));
Packet x_sign = pand(x, kSignMask);
Packet y_sign = pand(y, kSignMask);
Packet x_zero = pcmp_eq(x, pzero(x));
Packet y_zero = pcmp_eq(y, pzero(y));
const Packet k3PiO4 = pset1<Packet>(Scalar(3.0 * (EIGEN_PI / 4)));
// Various predicates about the inputs.
Packet x_signbit = pand(x, kSignMask);
Packet x_has_signbit = pcmp_lt(por(x_signbit, kPi), pzero(x));
Packet x_is_zero = pcmp_eq(x, pzero(x));
Packet x_neg = pandnot(x_has_signbit, x_is_zero);
Packet y_signbit = pand(y, kSignMask);
Packet y_is_zero = pcmp_eq(y, pzero(y));
Packet x_is_not_nan = pcmp_eq(x, x);
Packet y_is_not_nan = pcmp_eq(y, y);
@ -542,19 +546,21 @@ struct scalar_atan2_op {
Packet result = patan(pdiv(y, x));
// Compute shift for when x != 0 and y != 0.
Packet shift = pselect(x_neg, por(kPi, y_sign), pzero(x));
Packet shift = pselect(x_neg, por(kPi, y_signbit), pzero(x));
// Special cases:
// Handle x = +/-inf && y = +/-inf.
Packet is_not_nan = pcmp_eq(result, result);
result = pselect(is_not_nan, padd(shift, result),
pselect(x_neg, por(k3PiO4, y_sign), por(kPiO4, y_sign)));
// Handle x == +/-0.
result =
pselect(x_zero, pselect(y_zero, pzero(y), por(y_sign, kPiO2)), result);
pselect(is_not_nan, padd(shift, result),
pselect(x_neg, por(k3PiO4, y_signbit), por(kPiO4, y_signbit)));
// Handle x == +/-0.
result = pselect(
x_is_zero, pselect(y_is_zero, pzero(y), por(y_signbit, kPiO2)), result);
// Handle y == +/-0.
result = pselect(y_zero,
pselect(x_sign, por(y_sign, kPi), por(y_sign, pzero(y))),
result = pselect(
y_is_zero,
pselect(x_has_signbit, por(y_signbit, kPi), por(y_signbit, pzero(y))),
result);
// Handle NaN inputs.
Packet kQNaN = pset1<Packet>(NumTraits<Scalar>::quiet_NaN());