devtools/eigen
1
0
Fork 0
mirror of https://gitlab.com/libeigen/eigen.git synced 2026-04-10 11:34:33 +08:00
Code Issues Packages Projects Releases Wiki Activity

Implement plog_complex

Browse Source
This commit is contained in:
Damiano Franzò
2023-12-07 13:41:09 +01:00
committed by Rasmus Munk Larsen
parent 043442e21b
commit 7fd7a3f946
10 changed files with 223 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

63
Eigen/src/Core/arch/Default/GenericPacketMathFunctions.h
View File

@@ -964,6 +964,34 @@ EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet pdiv_complex(const Pa
return Packet(pdiv(result_scaled.v, y_max));
}
template <typename Packet>
EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet plog_complex(const Packet& x) {
typedef typename unpacket_traits<Packet>::type Scalar;
typedef typename Scalar::value_type RealScalar;
typedef typename unpacket_traits<Packet>::as_real RealPacket;
RealPacket real_mask_rp = peven_mask(x.v);
Packet real_mask(real_mask_rp);
// Real part
RealPacket x_flip = pcplxflip(x).v; // b, a
Packet x_norm = phypot_complex(x); // sqrt(a^2 + b^2), sqrt(a^2 + b^2)
RealPacket xlogr = plog(x_norm.v); // log(sqrt(a^2 + b^2)), log(sqrt(a^2 + b^2))
// Imag part
RealPacket ximg = patan2(x.v, x_flip); // atan2(a, b), atan2(b, a)
const RealPacket cst_pos_inf = pset1<RealPacket>(NumTraits<RealScalar>::infinity());
RealPacket x_abs = pabs(x.v);
RealPacket is_x_pos_inf = pcmp_eq(x_abs, cst_pos_inf);
RealPacket is_y_pos_inf = pcplxflip(Packet(is_x_pos_inf)).v;
RealPacket is_any_inf = por(is_x_pos_inf, is_y_pos_inf);
RealPacket xreal = pselect(is_any_inf, cst_pos_inf, xlogr);
Packet xres = pselect(real_mask, Packet(xreal), Packet(ximg)); // log(sqrt(a^2 + b^2)), atan2(b, a)
return xres;
}
template <typename Packet>
EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet psqrt_complex(const Packet& a) {
typedef typename unpacket_traits<Packet>::type Scalar;
@@ -1076,6 +1104,41 @@ EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet psqrt_complex(const P
return pselect(is_imag_inf, imag_inf_result, pselect(is_real_inf, real_inf_result, result));
}
// \internal \returns the norm of a complex number z = x + i*y, defined as sqrt(x^2 + y^2).
// Implemented using the hypot(a,b) algorithm from https://doi.org/10.48550/arXiv.1904.09481
template <typename Packet>
EIGEN_DEFINE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS Packet phypot_complex(const Packet& a) {
typedef typename unpacket_traits<Packet>::type Scalar;
typedef typename Scalar::value_type RealScalar;
typedef typename unpacket_traits<Packet>::as_real RealPacket;
const RealPacket cst_zero_rp = pset1<RealPacket>(static_cast<RealScalar>(0.0));
const RealPacket cst_minus_one_rp = pset1<RealPacket>(static_cast<RealScalar>(-1.0));
const RealPacket cst_two_rp = pset1<RealPacket>(static_cast<RealScalar>(2.0));
const RealPacket evenmask = peven_mask(a.v);
RealPacket a_abs = pabs(a.v);
RealPacket a_flip = pcplxflip(Packet(a_abs)).v; // |b|, |a|
RealPacket a_all = pselect(evenmask, a_abs, a_flip); // |a|, |a|
RealPacket b_all = pselect(evenmask, a_flip, a_abs); // |b|, |b|
RealPacket a2 = pmul(a.v, a.v); // |a^2, b^2|
RealPacket a2_flip = pcplxflip(Packet(a2)).v; // |b^2, a^2|
RealPacket h = psqrt(padd(a2, a2_flip)); // |sqrt(a^2 + b^2), sqrt(a^2 + b^2)|
RealPacket h_sq = pmul(h, h); // |a^2 + b^2, a^2 + b^2|
RealPacket a_sq = pselect(evenmask, a2, a2_flip); // |a^2, a^2|
RealPacket m_h_sq = pmul(h_sq, cst_minus_one_rp);
RealPacket m_a_sq = pmul(a_sq, cst_minus_one_rp);
RealPacket x = psub(psub(pmadd(h, h, m_h_sq), pmadd(b_all, b_all, psub(a_sq, h_sq))), pmadd(a_all, a_all, m_a_sq));
h = psub(h, pdiv(x, pmul(cst_two_rp, h))); // |h - x/(2*h), h - x/(2*h)|
// handle zero-case
RealPacket iszero = pcmp_eq(por(a_abs, a_flip), cst_zero_rp);
h = pandnot(h, iszero); // |sqrt(a^2+b^2), sqrt(a^2+b^2)|
return Packet(h); // |sqrt(a^2+b^2), sqrt(a^2+b^2)|
}
template <typename Packet>
struct psign_impl<Packet, std::enable_if_t<!NumTraits<typename unpacket_traits<Packet>::type>::IsComplex &&
!NumTraits<typename unpacket_traits<Packet>::type>::IsInteger>> {