1// This file is part of Eigen, a lightweight C++ template library 2// for linear algebra. 3// 4// Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr> 5// Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com> 6// 7// This Source Code Form is subject to the terms of the Mozilla 8// Public License v. 2.0. If a copy of the MPL was not distributed 9// with this file, You can obtain one at http://mozilla.org/MPL/2.0/. 10 11#ifndef EIGEN_GENERIC_PACKET_MATH_H 12#define EIGEN_GENERIC_PACKET_MATH_H 13 14namespace Eigen { 15 16namespace internal { 17 18/** \internal 19 * \file GenericPacketMath.h 20 * 21 * Default implementation for types not supported by the vectorization. 22 * In practice these functions are provided to make easier the writing 23 * of generic vectorized code. 24 */ 25 26#ifndef EIGEN_DEBUG_ALIGNED_LOAD 27#define EIGEN_DEBUG_ALIGNED_LOAD 28#endif 29 30#ifndef EIGEN_DEBUG_UNALIGNED_LOAD 31#define EIGEN_DEBUG_UNALIGNED_LOAD 32#endif 33 34#ifndef EIGEN_DEBUG_ALIGNED_STORE 35#define EIGEN_DEBUG_ALIGNED_STORE 36#endif 37 38#ifndef EIGEN_DEBUG_UNALIGNED_STORE 39#define EIGEN_DEBUG_UNALIGNED_STORE 40#endif 41 42struct default_packet_traits 43{ 44 enum { 45 HasHalfPacket = 0, 46 47 HasAdd = 1, 48 HasSub = 1, 49 HasMul = 1, 50 HasNegate = 1, 51 HasAbs = 1, 52 HasArg = 0, 53 HasAbs2 = 1, 54 HasMin = 1, 55 HasMax = 1, 56 HasConj = 1, 57 HasSetLinear = 1, 58 HasBlend = 0, 59 60 HasDiv = 0, 61 HasSqrt = 0, 62 HasRsqrt = 0, 63 HasExp = 0, 64 HasLog = 0, 65 HasLog1p = 0, 66 HasLog10 = 0, 67 HasPow = 0, 68 69 HasSin = 0, 70 HasCos = 0, 71 HasTan = 0, 72 HasASin = 0, 73 HasACos = 0, 74 HasATan = 0, 75 HasSinh = 0, 76 HasCosh = 0, 77 HasTanh = 0, 78 HasLGamma = 0, 79 HasDiGamma = 0, 80 HasZeta = 0, 81 HasPolygamma = 0, 82 HasErf = 0, 83 HasErfc = 0, 84 HasIGamma = 0, 85 HasIGammac = 0, 86 HasBetaInc = 0, 87 88 HasRound = 0, 89 HasFloor = 0, 90 HasCeil = 0, 91 92 HasSign = 0 93 }; 94}; 95 96template<typename T> struct packet_traits : default_packet_traits 97{ 98 typedef T type; 99 typedef T half; 100 enum { 101 Vectorizable = 0, 102 size = 1, 103 AlignedOnScalar = 0, 104 HasHalfPacket = 0 105 }; 106 enum { 107 HasAdd = 0, 108 HasSub = 0, 109 HasMul = 0, 110 HasNegate = 0, 111 HasAbs = 0, 112 HasAbs2 = 0, 113 HasMin = 0, 114 HasMax = 0, 115 HasConj = 0, 116 HasSetLinear = 0 117 }; 118}; 119 120template<typename T> struct packet_traits<const T> : packet_traits<T> { }; 121 122template <typename Src, typename Tgt> struct type_casting_traits { 123 enum { 124 VectorizedCast = 0, 125 SrcCoeffRatio = 1, 126 TgtCoeffRatio = 1 127 }; 128}; 129 130 131/** \internal \returns static_cast<TgtType>(a) (coeff-wise) */ 132template <typename SrcPacket, typename TgtPacket> 133EIGEN_DEVICE_FUNC inline TgtPacket 134pcast(const SrcPacket& a) { 135 return static_cast<TgtPacket>(a); 136} 137template <typename SrcPacket, typename TgtPacket> 138EIGEN_DEVICE_FUNC inline TgtPacket 139pcast(const SrcPacket& a, const SrcPacket& /*b*/) { 140 return static_cast<TgtPacket>(a); 141} 142 143template <typename SrcPacket, typename TgtPacket> 144EIGEN_DEVICE_FUNC inline TgtPacket 145pcast(const SrcPacket& a, const SrcPacket& /*b*/, const SrcPacket& /*c*/, const SrcPacket& /*d*/) { 146 return static_cast<TgtPacket>(a); 147} 148 149/** \internal \returns a + b (coeff-wise) */ 150template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 151padd(const Packet& a, 152 const Packet& b) { return a+b; } 153 154/** \internal \returns a - b (coeff-wise) */ 155template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 156psub(const Packet& a, 157 const Packet& b) { return a-b; } 158 159/** \internal \returns -a (coeff-wise) */ 160template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 161pnegate(const Packet& a) { return -a; } 162 163/** \internal \returns conj(a) (coeff-wise) */ 164 165template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 166pconj(const Packet& a) { return numext::conj(a); } 167 168/** \internal \returns a * b (coeff-wise) */ 169template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 170pmul(const Packet& a, 171 const Packet& b) { return a*b; } 172 173/** \internal \returns a / b (coeff-wise) */ 174template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 175pdiv(const Packet& a, 176 const Packet& b) { return a/b; } 177 178/** \internal \returns the min of \a a and \a b (coeff-wise) */ 179template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 180pmin(const Packet& a, 181 const Packet& b) { return numext::mini(a, b); } 182 183/** \internal \returns the max of \a a and \a b (coeff-wise) */ 184template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 185pmax(const Packet& a, 186 const Packet& b) { return numext::maxi(a, b); } 187 188/** \internal \returns the absolute value of \a a */ 189template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 190pabs(const Packet& a) { using std::abs; return abs(a); } 191 192/** \internal \returns the phase angle of \a a */ 193template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 194parg(const Packet& a) { using numext::arg; return arg(a); } 195 196/** \internal \returns the bitwise and of \a a and \a b */ 197template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 198pand(const Packet& a, const Packet& b) { return a & b; } 199 200/** \internal \returns the bitwise or of \a a and \a b */ 201template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 202por(const Packet& a, const Packet& b) { return a | b; } 203 204/** \internal \returns the bitwise xor of \a a and \a b */ 205template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 206pxor(const Packet& a, const Packet& b) { return a ^ b; } 207 208/** \internal \returns the bitwise andnot of \a a and \a b */ 209template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 210pandnot(const Packet& a, const Packet& b) { return a & (!b); } 211 212/** \internal \returns a packet version of \a *from, from must be 16 bytes aligned */ 213template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 214pload(const typename unpacket_traits<Packet>::type* from) { return *from; } 215 216/** \internal \returns a packet version of \a *from, (un-aligned load) */ 217template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 218ploadu(const typename unpacket_traits<Packet>::type* from) { return *from; } 219 220/** \internal \returns a packet with constant coefficients \a a, e.g.: (a,a,a,a) */ 221template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 222pset1(const typename unpacket_traits<Packet>::type& a) { return a; } 223 224/** \internal \returns a packet with constant coefficients \a a[0], e.g.: (a[0],a[0],a[0],a[0]) */ 225template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 226pload1(const typename unpacket_traits<Packet>::type *a) { return pset1<Packet>(*a); } 227 228/** \internal \returns a packet with elements of \a *from duplicated. 229 * For instance, for a packet of 8 elements, 4 scalars will be read from \a *from and 230 * duplicated to form: {from[0],from[0],from[1],from[1],from[2],from[2],from[3],from[3]} 231 * Currently, this function is only used for scalar * complex products. 232 */ 233template<typename Packet> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet 234ploaddup(const typename unpacket_traits<Packet>::type* from) { return *from; } 235 236/** \internal \returns a packet with elements of \a *from quadrupled. 237 * For instance, for a packet of 8 elements, 2 scalars will be read from \a *from and 238 * replicated to form: {from[0],from[0],from[0],from[0],from[1],from[1],from[1],from[1]} 239 * Currently, this function is only used in matrix products. 240 * For packet-size smaller or equal to 4, this function is equivalent to pload1 241 */ 242template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 243ploadquad(const typename unpacket_traits<Packet>::type* from) 244{ return pload1<Packet>(from); } 245 246/** \internal equivalent to 247 * \code 248 * a0 = pload1(a+0); 249 * a1 = pload1(a+1); 250 * a2 = pload1(a+2); 251 * a3 = pload1(a+3); 252 * \endcode 253 * \sa pset1, pload1, ploaddup, pbroadcast2 254 */ 255template<typename Packet> EIGEN_DEVICE_FUNC 256inline void pbroadcast4(const typename unpacket_traits<Packet>::type *a, 257 Packet& a0, Packet& a1, Packet& a2, Packet& a3) 258{ 259 a0 = pload1<Packet>(a+0); 260 a1 = pload1<Packet>(a+1); 261 a2 = pload1<Packet>(a+2); 262 a3 = pload1<Packet>(a+3); 263} 264 265/** \internal equivalent to 266 * \code 267 * a0 = pload1(a+0); 268 * a1 = pload1(a+1); 269 * \endcode 270 * \sa pset1, pload1, ploaddup, pbroadcast4 271 */ 272template<typename Packet> EIGEN_DEVICE_FUNC 273inline void pbroadcast2(const typename unpacket_traits<Packet>::type *a, 274 Packet& a0, Packet& a1) 275{ 276 a0 = pload1<Packet>(a+0); 277 a1 = pload1<Packet>(a+1); 278} 279 280/** \internal \brief Returns a packet with coefficients (a,a+1,...,a+packet_size-1). */ 281template<typename Packet> EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet 282plset(const typename unpacket_traits<Packet>::type& a) { return a; } 283 284/** \internal copy the packet \a from to \a *to, \a to must be 16 bytes aligned */ 285template<typename Scalar, typename Packet> EIGEN_DEVICE_FUNC inline void pstore(Scalar* to, const Packet& from) 286{ (*to) = from; } 287 288/** \internal copy the packet \a from to \a *to, (un-aligned store) */ 289template<typename Scalar, typename Packet> EIGEN_DEVICE_FUNC inline void pstoreu(Scalar* to, const Packet& from) 290{ (*to) = from; } 291 292 template<typename Scalar, typename Packet> EIGEN_DEVICE_FUNC inline Packet pgather(const Scalar* from, Index /*stride*/) 293 { return ploadu<Packet>(from); } 294 295 template<typename Scalar, typename Packet> EIGEN_DEVICE_FUNC inline void pscatter(Scalar* to, const Packet& from, Index /*stride*/) 296 { pstore(to, from); } 297 298/** \internal tries to do cache prefetching of \a addr */ 299template<typename Scalar> EIGEN_DEVICE_FUNC inline void prefetch(const Scalar* addr) 300{ 301#ifdef __CUDA_ARCH__ 302#if defined(__LP64__) 303 // 64-bit pointer operand constraint for inlined asm 304 asm(" prefetch.L1 [ %1 ];" : "=l"(addr) : "l"(addr)); 305#else 306 // 32-bit pointer operand constraint for inlined asm 307 asm(" prefetch.L1 [ %1 ];" : "=r"(addr) : "r"(addr)); 308#endif 309#elif (!EIGEN_COMP_MSVC) && (EIGEN_COMP_GNUC || EIGEN_COMP_CLANG || EIGEN_COMP_ICC) 310 __builtin_prefetch(addr); 311#endif 312} 313 314/** \internal \returns the first element of a packet */ 315template<typename Packet> EIGEN_DEVICE_FUNC inline typename unpacket_traits<Packet>::type pfirst(const Packet& a) 316{ return a; } 317 318/** \internal \returns a packet where the element i contains the sum of the packet of \a vec[i] */ 319template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 320preduxp(const Packet* vecs) { return vecs[0]; } 321 322/** \internal \returns the sum of the elements of \a a*/ 323template<typename Packet> EIGEN_DEVICE_FUNC inline typename unpacket_traits<Packet>::type predux(const Packet& a) 324{ return a; } 325 326/** \internal \returns the sum of the elements of \a a by block of 4 elements. 327 * For a packet {a0, a1, a2, a3, a4, a5, a6, a7}, it returns a half packet {a0+a4, a1+a5, a2+a6, a3+a7} 328 * For packet-size smaller or equal to 4, this boils down to a noop. 329 */ 330template<typename Packet> EIGEN_DEVICE_FUNC inline 331typename conditional<(unpacket_traits<Packet>::size%8)==0,typename unpacket_traits<Packet>::half,Packet>::type 332predux_downto4(const Packet& a) 333{ return a; } 334 335/** \internal \returns the product of the elements of \a a*/ 336template<typename Packet> EIGEN_DEVICE_FUNC inline typename unpacket_traits<Packet>::type predux_mul(const Packet& a) 337{ return a; } 338 339/** \internal \returns the min of the elements of \a a*/ 340template<typename Packet> EIGEN_DEVICE_FUNC inline typename unpacket_traits<Packet>::type predux_min(const Packet& a) 341{ return a; } 342 343/** \internal \returns the max of the elements of \a a*/ 344template<typename Packet> EIGEN_DEVICE_FUNC inline typename unpacket_traits<Packet>::type predux_max(const Packet& a) 345{ return a; } 346 347/** \internal \returns the reversed elements of \a a*/ 348template<typename Packet> EIGEN_DEVICE_FUNC inline Packet preverse(const Packet& a) 349{ return a; } 350 351/** \internal \returns \a a with real and imaginary part flipped (for complex type only) */ 352template<typename Packet> EIGEN_DEVICE_FUNC inline Packet pcplxflip(const Packet& a) 353{ 354 // FIXME: uncomment the following in case we drop the internal imag and real functions. 355// using std::imag; 356// using std::real; 357 return Packet(imag(a),real(a)); 358} 359 360/************************** 361* Special math functions 362***************************/ 363 364/** \internal \returns the sine of \a a (coeff-wise) */ 365template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 366Packet psin(const Packet& a) { using std::sin; return sin(a); } 367 368/** \internal \returns the cosine of \a a (coeff-wise) */ 369template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 370Packet pcos(const Packet& a) { using std::cos; return cos(a); } 371 372/** \internal \returns the tan of \a a (coeff-wise) */ 373template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 374Packet ptan(const Packet& a) { using std::tan; return tan(a); } 375 376/** \internal \returns the arc sine of \a a (coeff-wise) */ 377template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 378Packet pasin(const Packet& a) { using std::asin; return asin(a); } 379 380/** \internal \returns the arc cosine of \a a (coeff-wise) */ 381template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 382Packet pacos(const Packet& a) { using std::acos; return acos(a); } 383 384/** \internal \returns the arc tangent of \a a (coeff-wise) */ 385template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 386Packet patan(const Packet& a) { using std::atan; return atan(a); } 387 388/** \internal \returns the hyperbolic sine of \a a (coeff-wise) */ 389template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 390Packet psinh(const Packet& a) { using std::sinh; return sinh(a); } 391 392/** \internal \returns the hyperbolic cosine of \a a (coeff-wise) */ 393template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 394Packet pcosh(const Packet& a) { using std::cosh; return cosh(a); } 395 396/** \internal \returns the hyperbolic tan of \a a (coeff-wise) */ 397template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 398Packet ptanh(const Packet& a) { using std::tanh; return tanh(a); } 399 400/** \internal \returns the exp of \a a (coeff-wise) */ 401template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 402Packet pexp(const Packet& a) { using std::exp; return exp(a); } 403 404/** \internal \returns the log of \a a (coeff-wise) */ 405template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 406Packet plog(const Packet& a) { using std::log; return log(a); } 407 408/** \internal \returns the log1p of \a a (coeff-wise) */ 409template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 410Packet plog1p(const Packet& a) { return numext::log1p(a); } 411 412/** \internal \returns the log10 of \a a (coeff-wise) */ 413template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 414Packet plog10(const Packet& a) { using std::log10; return log10(a); } 415 416/** \internal \returns the square-root of \a a (coeff-wise) */ 417template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 418Packet psqrt(const Packet& a) { using std::sqrt; return sqrt(a); } 419 420/** \internal \returns the reciprocal square-root of \a a (coeff-wise) */ 421template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 422Packet prsqrt(const Packet& a) { 423 return pdiv(pset1<Packet>(1), psqrt(a)); 424} 425 426/** \internal \returns the rounded value of \a a (coeff-wise) */ 427template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 428Packet pround(const Packet& a) { using numext::round; return round(a); } 429 430/** \internal \returns the floor of \a a (coeff-wise) */ 431template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 432Packet pfloor(const Packet& a) { using numext::floor; return floor(a); } 433 434/** \internal \returns the ceil of \a a (coeff-wise) */ 435template<typename Packet> EIGEN_DECLARE_FUNCTION_ALLOWING_MULTIPLE_DEFINITIONS 436Packet pceil(const Packet& a) { using numext::ceil; return ceil(a); } 437 438/*************************************************************************** 439* The following functions might not have to be overwritten for vectorized types 440***************************************************************************/ 441 442/** \internal copy a packet with constant coeficient \a a (e.g., [a,a,a,a]) to \a *to. \a to must be 16 bytes aligned */ 443// NOTE: this function must really be templated on the packet type (think about different packet types for the same scalar type) 444template<typename Packet> 445inline void pstore1(typename unpacket_traits<Packet>::type* to, const typename unpacket_traits<Packet>::type& a) 446{ 447 pstore(to, pset1<Packet>(a)); 448} 449 450/** \internal \returns a * b + c (coeff-wise) */ 451template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 452pmadd(const Packet& a, 453 const Packet& b, 454 const Packet& c) 455{ return padd(pmul(a, b),c); } 456 457/** \internal \returns a packet version of \a *from. 458 * The pointer \a from must be aligned on a \a Alignment bytes boundary. */ 459template<typename Packet, int Alignment> 460EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE Packet ploadt(const typename unpacket_traits<Packet>::type* from) 461{ 462 if(Alignment >= unpacket_traits<Packet>::alignment) 463 return pload<Packet>(from); 464 else 465 return ploadu<Packet>(from); 466} 467 468/** \internal copy the packet \a from to \a *to. 469 * The pointer \a from must be aligned on a \a Alignment bytes boundary. */ 470template<typename Scalar, typename Packet, int Alignment> 471EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE void pstoret(Scalar* to, const Packet& from) 472{ 473 if(Alignment >= unpacket_traits<Packet>::alignment) 474 pstore(to, from); 475 else 476 pstoreu(to, from); 477} 478 479/** \internal \returns a packet version of \a *from. 480 * Unlike ploadt, ploadt_ro takes advantage of the read-only memory path on the 481 * hardware if available to speedup the loading of data that won't be modified 482 * by the current computation. 483 */ 484template<typename Packet, int LoadMode> 485EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE Packet ploadt_ro(const typename unpacket_traits<Packet>::type* from) 486{ 487 return ploadt<Packet, LoadMode>(from); 488} 489 490/** \internal default implementation of palign() allowing partial specialization */ 491template<int Offset,typename PacketType> 492struct palign_impl 493{ 494 // by default data are aligned, so there is nothing to be done :) 495 static inline void run(PacketType&, const PacketType&) {} 496}; 497 498/** \internal update \a first using the concatenation of the packet_size minus \a Offset last elements 499 * of \a first and \a Offset first elements of \a second. 500 * 501 * This function is currently only used to optimize matrix-vector products on unligned matrices. 502 * It takes 2 packets that represent a contiguous memory array, and returns a packet starting 503 * at the position \a Offset. For instance, for packets of 4 elements, we have: 504 * Input: 505 * - first = {f0,f1,f2,f3} 506 * - second = {s0,s1,s2,s3} 507 * Output: 508 * - if Offset==0 then {f0,f1,f2,f3} 509 * - if Offset==1 then {f1,f2,f3,s0} 510 * - if Offset==2 then {f2,f3,s0,s1} 511 * - if Offset==3 then {f3,s0,s1,s3} 512 */ 513template<int Offset,typename PacketType> 514inline void palign(PacketType& first, const PacketType& second) 515{ 516 palign_impl<Offset,PacketType>::run(first,second); 517} 518 519/*************************************************************************** 520* Fast complex products (GCC generates a function call which is very slow) 521***************************************************************************/ 522 523// Eigen+CUDA does not support complexes. 524#ifndef __CUDACC__ 525 526template<> inline std::complex<float> pmul(const std::complex<float>& a, const std::complex<float>& b) 527{ return std::complex<float>(real(a)*real(b) - imag(a)*imag(b), imag(a)*real(b) + real(a)*imag(b)); } 528 529template<> inline std::complex<double> pmul(const std::complex<double>& a, const std::complex<double>& b) 530{ return std::complex<double>(real(a)*real(b) - imag(a)*imag(b), imag(a)*real(b) + real(a)*imag(b)); } 531 532#endif 533 534 535/*************************************************************************** 536 * PacketBlock, that is a collection of N packets where the number of words 537 * in the packet is a multiple of N. 538***************************************************************************/ 539template <typename Packet,int N=unpacket_traits<Packet>::size> struct PacketBlock { 540 Packet packet[N]; 541}; 542 543template<typename Packet> EIGEN_DEVICE_FUNC inline void 544ptranspose(PacketBlock<Packet,1>& /*kernel*/) { 545 // Nothing to do in the scalar case, i.e. a 1x1 matrix. 546} 547 548/*************************************************************************** 549 * Selector, i.e. vector of N boolean values used to select (i.e. blend) 550 * words from 2 packets. 551***************************************************************************/ 552template <size_t N> struct Selector { 553 bool select[N]; 554}; 555 556template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 557pblend(const Selector<unpacket_traits<Packet>::size>& ifPacket, const Packet& thenPacket, const Packet& elsePacket) { 558 return ifPacket.select[0] ? thenPacket : elsePacket; 559} 560 561/** \internal \returns \a a with the first coefficient replaced by the scalar b */ 562template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 563pinsertfirst(const Packet& a, typename unpacket_traits<Packet>::type b) 564{ 565 // Default implementation based on pblend. 566 // It must be specialized for higher performance. 567 Selector<unpacket_traits<Packet>::size> mask; 568 mask.select[0] = true; 569 // This for loop should be optimized away by the compiler. 570 for(Index i=1; i<unpacket_traits<Packet>::size; ++i) 571 mask.select[i] = false; 572 return pblend(mask, pset1<Packet>(b), a); 573} 574 575/** \internal \returns \a a with the last coefficient replaced by the scalar b */ 576template<typename Packet> EIGEN_DEVICE_FUNC inline Packet 577pinsertlast(const Packet& a, typename unpacket_traits<Packet>::type b) 578{ 579 // Default implementation based on pblend. 580 // It must be specialized for higher performance. 581 Selector<unpacket_traits<Packet>::size> mask; 582 // This for loop should be optimized away by the compiler. 583 for(Index i=0; i<unpacket_traits<Packet>::size-1; ++i) 584 mask.select[i] = false; 585 mask.select[unpacket_traits<Packet>::size-1] = true; 586 return pblend(mask, pset1<Packet>(b), a); 587} 588 589} // end namespace internal 590 591} // end namespace Eigen 592 593#endif // EIGEN_GENERIC_PACKET_MATH_H 594