Home | History | Annotate | Download | only in NEON
      1 // This file is part of Eigen, a lightweight C++ template library
      2 // for linear algebra.
      3 //
      4 // Copyright (C) 2008-2009 Gael Guennebaud <gael.guennebaud (at) inria.fr>
      5 // Copyright (C) 2010 Konstantinos Margaritis <markos (at) codex.gr>
      6 // Heavily based on Gael's SSE version.
      7 //
      8 // This Source Code Form is subject to the terms of the Mozilla
      9 // Public License v. 2.0. If a copy of the MPL was not distributed
     10 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
     11 
     12 #ifndef EIGEN_PACKET_MATH_NEON_H
     13 #define EIGEN_PACKET_MATH_NEON_H
     14 
     15 namespace Eigen {
     16 
     17 namespace internal {
     18 
     19 #ifndef EIGEN_CACHEFRIENDLY_PRODUCT_THRESHOLD
     20 #define EIGEN_CACHEFRIENDLY_PRODUCT_THRESHOLD 8
     21 #endif
     22 
     23 // FIXME NEON has 16 quad registers, but since the current register allocator
     24 // is so bad, it is much better to reduce it to 8
     25 #ifndef EIGEN_ARCH_DEFAULT_NUMBER_OF_REGISTERS
     26 #define EIGEN_ARCH_DEFAULT_NUMBER_OF_REGISTERS 8
     27 #endif
     28 
     29 typedef float32x4_t Packet4f;
     30 typedef int32x4_t   Packet4i;
     31 typedef uint32x4_t  Packet4ui;
     32 
     33 #define _EIGEN_DECLARE_CONST_Packet4f(NAME,X) \
     34   const Packet4f p4f_##NAME = pset1<Packet4f>(X)
     35 
     36 #define _EIGEN_DECLARE_CONST_Packet4f_FROM_INT(NAME,X) \
     37   const Packet4f p4f_##NAME = vreinterpretq_f32_u32(pset1<int>(X))
     38 
     39 #define _EIGEN_DECLARE_CONST_Packet4i(NAME,X) \
     40   const Packet4i p4i_##NAME = pset1<Packet4i>(X)
     41 
     42 #if defined(__llvm__) && !defined(__clang__)
     43   //Special treatment for Apple's llvm-gcc, its NEON packet types are unions
     44   #define EIGEN_INIT_NEON_PACKET2(X, Y)       {{X, Y}}
     45   #define EIGEN_INIT_NEON_PACKET4(X, Y, Z, W) {{X, Y, Z, W}}
     46 #else
     47   //Default initializer for packets
     48   #define EIGEN_INIT_NEON_PACKET2(X, Y)       {X, Y}
     49   #define EIGEN_INIT_NEON_PACKET4(X, Y, Z, W) {X, Y, Z, W}
     50 #endif
     51 
     52 #ifndef __pld
     53 #define __pld(x) asm volatile ( "   pld [%[addr]]\n" :: [addr] "r" (x) : "cc" );
     54 #endif
     55 
     56 template<> struct packet_traits<float>  : default_packet_traits
     57 {
     58   typedef Packet4f type;
     59   enum {
     60     Vectorizable = 1,
     61     AlignedOnScalar = 1,
     62     size = 4,
     63 
     64     HasDiv  = 1,
     65     // FIXME check the Has*
     66     HasSin  = 0,
     67     HasCos  = 0,
     68     HasLog  = 0,
     69     HasExp  = 0,
     70     HasSqrt = 0
     71   };
     72 };
     73 template<> struct packet_traits<int>    : default_packet_traits
     74 {
     75   typedef Packet4i type;
     76   enum {
     77     Vectorizable = 1,
     78     AlignedOnScalar = 1,
     79     size=4
     80     // FIXME check the Has*
     81   };
     82 };
     83 
     84 #if EIGEN_GNUC_AT_MOST(4,4) && !defined(__llvm__)
     85 // workaround gcc 4.2, 4.3 and 4.4 compilatin issue
     86 EIGEN_STRONG_INLINE float32x4_t vld1q_f32(const float* x) { return ::vld1q_f32((const float32_t*)x); }
     87 EIGEN_STRONG_INLINE float32x2_t vld1_f32 (const float* x) { return ::vld1_f32 ((const float32_t*)x); }
     88 EIGEN_STRONG_INLINE void        vst1q_f32(float* to, float32x4_t from) { ::vst1q_f32((float32_t*)to,from); }
     89 EIGEN_STRONG_INLINE void        vst1_f32 (float* to, float32x2_t from) { ::vst1_f32 ((float32_t*)to,from); }
     90 #endif
     91 
     92 template<> struct unpacket_traits<Packet4f> { typedef float  type; enum {size=4}; };
     93 template<> struct unpacket_traits<Packet4i> { typedef int    type; enum {size=4}; };
     94 
     95 template<> EIGEN_STRONG_INLINE Packet4f pset1<Packet4f>(const float&  from) { return vdupq_n_f32(from); }
     96 template<> EIGEN_STRONG_INLINE Packet4i pset1<Packet4i>(const int&    from)   { return vdupq_n_s32(from); }
     97 
     98 template<> EIGEN_STRONG_INLINE Packet4f plset<float>(const float& a)
     99 {
    100   Packet4f countdown = EIGEN_INIT_NEON_PACKET4(0, 1, 2, 3);
    101   return vaddq_f32(pset1<Packet4f>(a), countdown);
    102 }
    103 template<> EIGEN_STRONG_INLINE Packet4i plset<int>(const int& a)
    104 {
    105   Packet4i countdown = EIGEN_INIT_NEON_PACKET4(0, 1, 2, 3);
    106   return vaddq_s32(pset1<Packet4i>(a), countdown);
    107 }
    108 
    109 template<> EIGEN_STRONG_INLINE Packet4f padd<Packet4f>(const Packet4f& a, const Packet4f& b) { return vaddq_f32(a,b); }
    110 template<> EIGEN_STRONG_INLINE Packet4i padd<Packet4i>(const Packet4i& a, const Packet4i& b) { return vaddq_s32(a,b); }
    111 
    112 template<> EIGEN_STRONG_INLINE Packet4f psub<Packet4f>(const Packet4f& a, const Packet4f& b) { return vsubq_f32(a,b); }
    113 template<> EIGEN_STRONG_INLINE Packet4i psub<Packet4i>(const Packet4i& a, const Packet4i& b) { return vsubq_s32(a,b); }
    114 
    115 template<> EIGEN_STRONG_INLINE Packet4f pnegate(const Packet4f& a) { return vnegq_f32(a); }
    116 template<> EIGEN_STRONG_INLINE Packet4i pnegate(const Packet4i& a) { return vnegq_s32(a); }
    117 
    118 template<> EIGEN_STRONG_INLINE Packet4f pmul<Packet4f>(const Packet4f& a, const Packet4f& b) { return vmulq_f32(a,b); }
    119 template<> EIGEN_STRONG_INLINE Packet4i pmul<Packet4i>(const Packet4i& a, const Packet4i& b) { return vmulq_s32(a,b); }
    120 
    121 template<> EIGEN_STRONG_INLINE Packet4f pdiv<Packet4f>(const Packet4f& a, const Packet4f& b)
    122 {
    123   Packet4f inv, restep, div;
    124 
    125   // NEON does not offer a divide instruction, we have to do a reciprocal approximation
    126   // However NEON in contrast to other SIMD engines (AltiVec/SSE), offers
    127   // a reciprocal estimate AND a reciprocal step -which saves a few instructions
    128   // vrecpeq_f32() returns an estimate to 1/b, which we will finetune with
    129   // Newton-Raphson and vrecpsq_f32()
    130   inv = vrecpeq_f32(b);
    131 
    132   // This returns a differential, by which we will have to multiply inv to get a better
    133   // approximation of 1/b.
    134   restep = vrecpsq_f32(b, inv);
    135   inv = vmulq_f32(restep, inv);
    136 
    137   // Finally, multiply a by 1/b and get the wanted result of the division.
    138   div = vmulq_f32(a, inv);
    139 
    140   return div;
    141 }
    142 template<> EIGEN_STRONG_INLINE Packet4i pdiv<Packet4i>(const Packet4i& /*a*/, const Packet4i& /*b*/)
    143 { eigen_assert(false && "packet integer division are not supported by NEON");
    144   return pset1<Packet4i>(0);
    145 }
    146 
    147 // for some weird raisons, it has to be overloaded for packet of integers
    148 template<> EIGEN_STRONG_INLINE Packet4f pmadd(const Packet4f& a, const Packet4f& b, const Packet4f& c) { return vmlaq_f32(c,a,b); }
    149 template<> EIGEN_STRONG_INLINE Packet4i pmadd(const Packet4i& a, const Packet4i& b, const Packet4i& c) { return vmlaq_s32(c,a,b); }
    150 
    151 template<> EIGEN_STRONG_INLINE Packet4f pmin<Packet4f>(const Packet4f& a, const Packet4f& b) { return vminq_f32(a,b); }
    152 template<> EIGEN_STRONG_INLINE Packet4i pmin<Packet4i>(const Packet4i& a, const Packet4i& b) { return vminq_s32(a,b); }
    153 
    154 template<> EIGEN_STRONG_INLINE Packet4f pmax<Packet4f>(const Packet4f& a, const Packet4f& b) { return vmaxq_f32(a,b); }
    155 template<> EIGEN_STRONG_INLINE Packet4i pmax<Packet4i>(const Packet4i& a, const Packet4i& b) { return vmaxq_s32(a,b); }
    156 
    157 // Logical Operations are not supported for float, so we have to reinterpret casts using NEON intrinsics
    158 template<> EIGEN_STRONG_INLINE Packet4f pand<Packet4f>(const Packet4f& a, const Packet4f& b)
    159 {
    160   return vreinterpretq_f32_u32(vandq_u32(vreinterpretq_u32_f32(a),vreinterpretq_u32_f32(b)));
    161 }
    162 template<> EIGEN_STRONG_INLINE Packet4i pand<Packet4i>(const Packet4i& a, const Packet4i& b) { return vandq_s32(a,b); }
    163 
    164 template<> EIGEN_STRONG_INLINE Packet4f por<Packet4f>(const Packet4f& a, const Packet4f& b)
    165 {
    166   return vreinterpretq_f32_u32(vorrq_u32(vreinterpretq_u32_f32(a),vreinterpretq_u32_f32(b)));
    167 }
    168 template<> EIGEN_STRONG_INLINE Packet4i por<Packet4i>(const Packet4i& a, const Packet4i& b) { return vorrq_s32(a,b); }
    169 
    170 template<> EIGEN_STRONG_INLINE Packet4f pxor<Packet4f>(const Packet4f& a, const Packet4f& b)
    171 {
    172   return vreinterpretq_f32_u32(veorq_u32(vreinterpretq_u32_f32(a),vreinterpretq_u32_f32(b)));
    173 }
    174 template<> EIGEN_STRONG_INLINE Packet4i pxor<Packet4i>(const Packet4i& a, const Packet4i& b) { return veorq_s32(a,b); }
    175 
    176 template<> EIGEN_STRONG_INLINE Packet4f pandnot<Packet4f>(const Packet4f& a, const Packet4f& b)
    177 {
    178   return vreinterpretq_f32_u32(vbicq_u32(vreinterpretq_u32_f32(a),vreinterpretq_u32_f32(b)));
    179 }
    180 template<> EIGEN_STRONG_INLINE Packet4i pandnot<Packet4i>(const Packet4i& a, const Packet4i& b) { return vbicq_s32(a,b); }
    181 
    182 template<> EIGEN_STRONG_INLINE Packet4f pload<Packet4f>(const float* from) { EIGEN_DEBUG_ALIGNED_LOAD return vld1q_f32(from); }
    183 template<> EIGEN_STRONG_INLINE Packet4i pload<Packet4i>(const int*   from) { EIGEN_DEBUG_ALIGNED_LOAD return vld1q_s32(from); }
    184 
    185 template<> EIGEN_STRONG_INLINE Packet4f ploadu<Packet4f>(const float* from) { EIGEN_DEBUG_UNALIGNED_LOAD return vld1q_f32(from); }
    186 template<> EIGEN_STRONG_INLINE Packet4i ploadu<Packet4i>(const int* from)   { EIGEN_DEBUG_UNALIGNED_LOAD return vld1q_s32(from); }
    187 
    188 template<> EIGEN_STRONG_INLINE Packet4f ploaddup<Packet4f>(const float*   from)
    189 {
    190   float32x2_t lo, hi;
    191   lo = vdup_n_f32(*from);
    192   hi = vdup_n_f32(*(from+1));
    193   return vcombine_f32(lo, hi);
    194 }
    195 template<> EIGEN_STRONG_INLINE Packet4i ploaddup<Packet4i>(const int*     from)
    196 {
    197   int32x2_t lo, hi;
    198   lo = vdup_n_s32(*from);
    199   hi = vdup_n_s32(*(from+1));
    200   return vcombine_s32(lo, hi);
    201 }
    202 
    203 template<> EIGEN_STRONG_INLINE void pstore<float>(float*   to, const Packet4f& from) { EIGEN_DEBUG_ALIGNED_STORE vst1q_f32(to, from); }
    204 template<> EIGEN_STRONG_INLINE void pstore<int>(int*       to, const Packet4i& from) { EIGEN_DEBUG_ALIGNED_STORE vst1q_s32(to, from); }
    205 
    206 template<> EIGEN_STRONG_INLINE void pstoreu<float>(float*  to, const Packet4f& from) { EIGEN_DEBUG_UNALIGNED_STORE vst1q_f32(to, from); }
    207 template<> EIGEN_STRONG_INLINE void pstoreu<int>(int*      to, const Packet4i& from) { EIGEN_DEBUG_UNALIGNED_STORE vst1q_s32(to, from); }
    208 
    209 template<> EIGEN_STRONG_INLINE void prefetch<float>(const float* addr) { __pld(addr); }
    210 template<> EIGEN_STRONG_INLINE void prefetch<int>(const int*     addr) { __pld(addr); }
    211 
    212 // FIXME only store the 2 first elements ?
    213 template<> EIGEN_STRONG_INLINE float  pfirst<Packet4f>(const Packet4f& a) { float EIGEN_ALIGN16 x[4]; vst1q_f32(x, a); return x[0]; }
    214 template<> EIGEN_STRONG_INLINE int    pfirst<Packet4i>(const Packet4i& a) { int   EIGEN_ALIGN16 x[4]; vst1q_s32(x, a); return x[0]; }
    215 
    216 template<> EIGEN_STRONG_INLINE Packet4f preverse(const Packet4f& a) {
    217   float32x2_t a_lo, a_hi;
    218   Packet4f a_r64;
    219 
    220   a_r64 = vrev64q_f32(a);
    221   a_lo = vget_low_f32(a_r64);
    222   a_hi = vget_high_f32(a_r64);
    223   return vcombine_f32(a_hi, a_lo);
    224 }
    225 template<> EIGEN_STRONG_INLINE Packet4i preverse(const Packet4i& a) {
    226   int32x2_t a_lo, a_hi;
    227   Packet4i a_r64;
    228 
    229   a_r64 = vrev64q_s32(a);
    230   a_lo = vget_low_s32(a_r64);
    231   a_hi = vget_high_s32(a_r64);
    232   return vcombine_s32(a_hi, a_lo);
    233 }
    234 template<> EIGEN_STRONG_INLINE Packet4f pabs(const Packet4f& a) { return vabsq_f32(a); }
    235 template<> EIGEN_STRONG_INLINE Packet4i pabs(const Packet4i& a) { return vabsq_s32(a); }
    236 
    237 template<> EIGEN_STRONG_INLINE float predux<Packet4f>(const Packet4f& a)
    238 {
    239   float32x2_t a_lo, a_hi, sum;
    240   float s[2];
    241 
    242   a_lo = vget_low_f32(a);
    243   a_hi = vget_high_f32(a);
    244   sum = vpadd_f32(a_lo, a_hi);
    245   sum = vpadd_f32(sum, sum);
    246   vst1_f32(s, sum);
    247 
    248   return s[0];
    249 }
    250 
    251 template<> EIGEN_STRONG_INLINE Packet4f preduxp<Packet4f>(const Packet4f* vecs)
    252 {
    253   float32x4x2_t vtrn1, vtrn2, res1, res2;
    254   Packet4f sum1, sum2, sum;
    255 
    256   // NEON zip performs interleaving of the supplied vectors.
    257   // We perform two interleaves in a row to acquire the transposed vector
    258   vtrn1 = vzipq_f32(vecs[0], vecs[2]);
    259   vtrn2 = vzipq_f32(vecs[1], vecs[3]);
    260   res1 = vzipq_f32(vtrn1.val[0], vtrn2.val[0]);
    261   res2 = vzipq_f32(vtrn1.val[1], vtrn2.val[1]);
    262 
    263   // Do the addition of the resulting vectors
    264   sum1 = vaddq_f32(res1.val[0], res1.val[1]);
    265   sum2 = vaddq_f32(res2.val[0], res2.val[1]);
    266   sum = vaddq_f32(sum1, sum2);
    267 
    268   return sum;
    269 }
    270 
    271 template<> EIGEN_STRONG_INLINE int predux<Packet4i>(const Packet4i& a)
    272 {
    273   int32x2_t a_lo, a_hi, sum;
    274   int32_t s[2];
    275 
    276   a_lo = vget_low_s32(a);
    277   a_hi = vget_high_s32(a);
    278   sum = vpadd_s32(a_lo, a_hi);
    279   sum = vpadd_s32(sum, sum);
    280   vst1_s32(s, sum);
    281 
    282   return s[0];
    283 }
    284 
    285 template<> EIGEN_STRONG_INLINE Packet4i preduxp<Packet4i>(const Packet4i* vecs)
    286 {
    287   int32x4x2_t vtrn1, vtrn2, res1, res2;
    288   Packet4i sum1, sum2, sum;
    289 
    290   // NEON zip performs interleaving of the supplied vectors.
    291   // We perform two interleaves in a row to acquire the transposed vector
    292   vtrn1 = vzipq_s32(vecs[0], vecs[2]);
    293   vtrn2 = vzipq_s32(vecs[1], vecs[3]);
    294   res1 = vzipq_s32(vtrn1.val[0], vtrn2.val[0]);
    295   res2 = vzipq_s32(vtrn1.val[1], vtrn2.val[1]);
    296 
    297   // Do the addition of the resulting vectors
    298   sum1 = vaddq_s32(res1.val[0], res1.val[1]);
    299   sum2 = vaddq_s32(res2.val[0], res2.val[1]);
    300   sum = vaddq_s32(sum1, sum2);
    301 
    302   return sum;
    303 }
    304 
    305 // Other reduction functions:
    306 // mul
    307 template<> EIGEN_STRONG_INLINE float predux_mul<Packet4f>(const Packet4f& a)
    308 {
    309   float32x2_t a_lo, a_hi, prod;
    310   float s[2];
    311 
    312   // Get a_lo = |a1|a2| and a_hi = |a3|a4|
    313   a_lo = vget_low_f32(a);
    314   a_hi = vget_high_f32(a);
    315   // Get the product of a_lo * a_hi -> |a1*a3|a2*a4|
    316   prod = vmul_f32(a_lo, a_hi);
    317   // Multiply prod with its swapped value |a2*a4|a1*a3|
    318   prod = vmul_f32(prod, vrev64_f32(prod));
    319   vst1_f32(s, prod);
    320 
    321   return s[0];
    322 }
    323 template<> EIGEN_STRONG_INLINE int predux_mul<Packet4i>(const Packet4i& a)
    324 {
    325   int32x2_t a_lo, a_hi, prod;
    326   int32_t s[2];
    327 
    328   // Get a_lo = |a1|a2| and a_hi = |a3|a4|
    329   a_lo = vget_low_s32(a);
    330   a_hi = vget_high_s32(a);
    331   // Get the product of a_lo * a_hi -> |a1*a3|a2*a4|
    332   prod = vmul_s32(a_lo, a_hi);
    333   // Multiply prod with its swapped value |a2*a4|a1*a3|
    334   prod = vmul_s32(prod, vrev64_s32(prod));
    335   vst1_s32(s, prod);
    336 
    337   return s[0];
    338 }
    339 
    340 // min
    341 template<> EIGEN_STRONG_INLINE float predux_min<Packet4f>(const Packet4f& a)
    342 {
    343   float32x2_t a_lo, a_hi, min;
    344   float s[2];
    345 
    346   a_lo = vget_low_f32(a);
    347   a_hi = vget_high_f32(a);
    348   min = vpmin_f32(a_lo, a_hi);
    349   min = vpmin_f32(min, min);
    350   vst1_f32(s, min);
    351 
    352   return s[0];
    353 }
    354 template<> EIGEN_STRONG_INLINE int predux_min<Packet4i>(const Packet4i& a)
    355 {
    356   int32x2_t a_lo, a_hi, min;
    357   int32_t s[2];
    358 
    359   a_lo = vget_low_s32(a);
    360   a_hi = vget_high_s32(a);
    361   min = vpmin_s32(a_lo, a_hi);
    362   min = vpmin_s32(min, min);
    363   vst1_s32(s, min);
    364 
    365   return s[0];
    366 }
    367 
    368 // max
    369 template<> EIGEN_STRONG_INLINE float predux_max<Packet4f>(const Packet4f& a)
    370 {
    371   float32x2_t a_lo, a_hi, max;
    372   float s[2];
    373 
    374   a_lo = vget_low_f32(a);
    375   a_hi = vget_high_f32(a);
    376   max = vpmax_f32(a_lo, a_hi);
    377   max = vpmax_f32(max, max);
    378   vst1_f32(s, max);
    379 
    380   return s[0];
    381 }
    382 template<> EIGEN_STRONG_INLINE int predux_max<Packet4i>(const Packet4i& a)
    383 {
    384   int32x2_t a_lo, a_hi, max;
    385   int32_t s[2];
    386 
    387   a_lo = vget_low_s32(a);
    388   a_hi = vget_high_s32(a);
    389   max = vpmax_s32(a_lo, a_hi);
    390   max = vpmax_s32(max, max);
    391   vst1_s32(s, max);
    392 
    393   return s[0];
    394 }
    395 
    396 // this PALIGN_NEON business is to work around a bug in LLVM Clang 3.0 causing incorrect compilation errors,
    397 // see bug 347 and this LLVM bug: http://llvm.org/bugs/show_bug.cgi?id=11074
    398 #define PALIGN_NEON(Offset,Type,Command) \
    399 template<>\
    400 struct palign_impl<Offset,Type>\
    401 {\
    402     EIGEN_STRONG_INLINE static void run(Type& first, const Type& second)\
    403     {\
    404         if (Offset!=0)\
    405             first = Command(first, second, Offset);\
    406     }\
    407 };\
    408 
    409 PALIGN_NEON(0,Packet4f,vextq_f32)
    410 PALIGN_NEON(1,Packet4f,vextq_f32)
    411 PALIGN_NEON(2,Packet4f,vextq_f32)
    412 PALIGN_NEON(3,Packet4f,vextq_f32)
    413 PALIGN_NEON(0,Packet4i,vextq_s32)
    414 PALIGN_NEON(1,Packet4i,vextq_s32)
    415 PALIGN_NEON(2,Packet4i,vextq_s32)
    416 PALIGN_NEON(3,Packet4i,vextq_s32)
    417 
    418 #undef PALIGN_NEON
    419 
    420 } // end namespace internal
    421 
    422 } // end namespace Eigen
    423 
    424 #endif // EIGEN_PACKET_MATH_NEON_H
    425