1// This file is part of Eigen, a lightweight C++ template library
2// for linear algebra.
3//
4// Copyright (C) 2008 Konstantinos Margaritis <markos@codex.gr>
5//
6// This Source Code Form is subject to the terms of the Mozilla
7// Public License v. 2.0. If a copy of the MPL was not distributed
8// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
9
10#ifndef EIGEN_PACKET_MATH_ALTIVEC_H
11#define EIGEN_PACKET_MATH_ALTIVEC_H
12
13namespace Eigen {
14
15namespace internal {
16
17#ifndef EIGEN_CACHEFRIENDLY_PRODUCT_THRESHOLD
18#define EIGEN_CACHEFRIENDLY_PRODUCT_THRESHOLD 4
19#endif
20
21#ifndef EIGEN_HAS_FUSE_CJMADD
22#define EIGEN_HAS_FUSE_CJMADD 1
23#endif
24
25// NOTE Altivec has 32 registers, but Eigen only accepts a value of 8 or 16
26#ifndef EIGEN_ARCH_DEFAULT_NUMBER_OF_REGISTERS
27#define EIGEN_ARCH_DEFAULT_NUMBER_OF_REGISTERS 16
28#endif
29
30typedef __vector float          Packet4f;
31typedef __vector int            Packet4i;
32typedef __vector unsigned int   Packet4ui;
33typedef __vector __bool int     Packet4bi;
34typedef __vector short int      Packet8i;
35typedef __vector unsigned char  Packet16uc;
36
37// We don't want to write the same code all the time, but we need to reuse the constants
38// and it doesn't really work to declare them global, so we define macros instead
39
40#define _EIGEN_DECLARE_CONST_FAST_Packet4f(NAME,X) \
41  Packet4f p4f_##NAME = (Packet4f) vec_splat_s32(X)
42
43#define _EIGEN_DECLARE_CONST_FAST_Packet4i(NAME,X) \
44  Packet4i p4i_##NAME = vec_splat_s32(X)
45
46#define _EIGEN_DECLARE_CONST_Packet4f(NAME,X) \
47  Packet4f p4f_##NAME = pset1<Packet4f>(X)
48
49#define _EIGEN_DECLARE_CONST_Packet4f_FROM_INT(NAME,X) \
50  Packet4f p4f_##NAME = vreinterpretq_f32_u32(pset1<int>(X))
51
52#define _EIGEN_DECLARE_CONST_Packet4i(NAME,X) \
53  Packet4i p4i_##NAME = pset1<Packet4i>(X)
54
55#define DST_CHAN 1
56#define DST_CTRL(size, count, stride) (((size) << 24) | ((count) << 16) | (stride))
57
58// Define global static constants:
59static Packet4f p4f_COUNTDOWN = { 3.0, 2.0, 1.0, 0.0 };
60static Packet4i p4i_COUNTDOWN = { 3, 2, 1, 0 };
61static Packet16uc p16uc_REVERSE = {12,13,14,15, 8,9,10,11, 4,5,6,7, 0,1,2,3};
62static Packet16uc p16uc_FORWARD = vec_lvsl(0, (float*)0);
63static Packet16uc p16uc_DUPLICATE = {0,1,2,3, 0,1,2,3, 4,5,6,7, 4,5,6,7};
64
65static _EIGEN_DECLARE_CONST_FAST_Packet4f(ZERO, 0);
66static _EIGEN_DECLARE_CONST_FAST_Packet4i(ZERO, 0);
67static _EIGEN_DECLARE_CONST_FAST_Packet4i(ONE,1);
68static _EIGEN_DECLARE_CONST_FAST_Packet4i(MINUS16,-16);
69static _EIGEN_DECLARE_CONST_FAST_Packet4i(MINUS1,-1);
70static Packet4f p4f_ONE = vec_ctf(p4i_ONE, 0);
71static Packet4f p4f_ZERO_ = (Packet4f) vec_sl((Packet4ui)p4i_MINUS1, (Packet4ui)p4i_MINUS1);
72
73template<> struct packet_traits<float>  : default_packet_traits
74{
75  typedef Packet4f type;
76  enum {
77    Vectorizable = 1,
78    AlignedOnScalar = 1,
79    size=4,
80
81    // FIXME check the Has*
82    HasSin  = 0,
83    HasCos  = 0,
84    HasLog  = 0,
85    HasExp  = 0,
86    HasSqrt = 0
87  };
88};
89template<> struct packet_traits<int>    : default_packet_traits
90{
91  typedef Packet4i type;
92  enum {
93    // FIXME check the Has*
94    Vectorizable = 1,
95    AlignedOnScalar = 1,
96    size=4
97  };
98};
99
100template<> struct unpacket_traits<Packet4f> { typedef float  type; enum {size=4}; };
101template<> struct unpacket_traits<Packet4i> { typedef int    type; enum {size=4}; };
102/*
103inline std::ostream & operator <<(std::ostream & s, const Packet4f & v)
104{
105  union {
106    Packet4f   v;
107    float n[4];
108  } vt;
109  vt.v = v;
110  s << vt.n[0] << ", " << vt.n[1] << ", " << vt.n[2] << ", " << vt.n[3];
111  return s;
112}
113
114inline std::ostream & operator <<(std::ostream & s, const Packet4i & v)
115{
116  union {
117    Packet4i   v;
118    int n[4];
119  } vt;
120  vt.v = v;
121  s << vt.n[0] << ", " << vt.n[1] << ", " << vt.n[2] << ", " << vt.n[3];
122  return s;
123}
124
125inline std::ostream & operator <<(std::ostream & s, const Packet4ui & v)
126{
127  union {
128    Packet4ui   v;
129    unsigned int n[4];
130  } vt;
131  vt.v = v;
132  s << vt.n[0] << ", " << vt.n[1] << ", " << vt.n[2] << ", " << vt.n[3];
133  return s;
134}
135
136inline std::ostream & operator <<(std::ostream & s, const Packetbi & v)
137{
138  union {
139    Packet4bi v;
140    unsigned int n[4];
141  } vt;
142  vt.v = v;
143  s << vt.n[0] << ", " << vt.n[1] << ", " << vt.n[2] << ", " << vt.n[3];
144  return s;
145}
146*/
147template<> EIGEN_STRONG_INLINE Packet4f pset1<Packet4f>(const float&  from) {
148  // Taken from http://developer.apple.com/hardwaredrivers/ve/alignment.html
149  float EIGEN_ALIGN16 af[4];
150  af[0] = from;
151  Packet4f vc = vec_ld(0, af);
152  vc = vec_splat(vc, 0);
153  return vc;
154}
155
156template<> EIGEN_STRONG_INLINE Packet4i pset1<Packet4i>(const int&    from)   {
157  int EIGEN_ALIGN16 ai[4];
158  ai[0] = from;
159  Packet4i vc = vec_ld(0, ai);
160  vc = vec_splat(vc, 0);
161  return vc;
162}
163
164template<> EIGEN_STRONG_INLINE Packet4f plset<float>(const float& a) { return vec_add(pset1<Packet4f>(a), p4f_COUNTDOWN); }
165template<> EIGEN_STRONG_INLINE Packet4i plset<int>(const int& a)     { return vec_add(pset1<Packet4i>(a), p4i_COUNTDOWN); }
166
167template<> EIGEN_STRONG_INLINE Packet4f padd<Packet4f>(const Packet4f& a, const Packet4f& b) { return vec_add(a,b); }
168template<> EIGEN_STRONG_INLINE Packet4i padd<Packet4i>(const Packet4i& a, const Packet4i& b) { return vec_add(a,b); }
169
170template<> EIGEN_STRONG_INLINE Packet4f psub<Packet4f>(const Packet4f& a, const Packet4f& b) { return vec_sub(a,b); }
171template<> EIGEN_STRONG_INLINE Packet4i psub<Packet4i>(const Packet4i& a, const Packet4i& b) { return vec_sub(a,b); }
172
173template<> EIGEN_STRONG_INLINE Packet4f pnegate(const Packet4f& a) { return psub<Packet4f>(p4f_ZERO, a); }
174template<> EIGEN_STRONG_INLINE Packet4i pnegate(const Packet4i& a) { return psub<Packet4i>(p4i_ZERO, a); }
175
176template<> EIGEN_STRONG_INLINE Packet4f pconj(const Packet4f& a) { return a; }
177template<> EIGEN_STRONG_INLINE Packet4i pconj(const Packet4i& a) { return a; }
178
179template<> EIGEN_STRONG_INLINE Packet4f pmul<Packet4f>(const Packet4f& a, const Packet4f& b) { return vec_madd(a,b,p4f_ZERO); }
180/* Commented out: it's actually slower than processing it scalar
181 *
182template<> EIGEN_STRONG_INLINE Packet4i pmul<Packet4i>(const Packet4i& a, const Packet4i& b)
183{
184  // Detailed in: http://freevec.org/content/32bit_signed_integer_multiplication_altivec
185  //Set up constants, variables
186  Packet4i a1, b1, bswap, low_prod, high_prod, prod, prod_, v1sel;
187
188  // Get the absolute values
189  a1  = vec_abs(a);
190  b1  = vec_abs(b);
191
192  // Get the signs using xor
193  Packet4bi sgn = (Packet4bi) vec_cmplt(vec_xor(a, b), p4i_ZERO);
194
195  // Do the multiplication for the asbolute values.
196  bswap = (Packet4i) vec_rl((Packet4ui) b1, (Packet4ui) p4i_MINUS16 );
197  low_prod = vec_mulo((Packet8i) a1, (Packet8i)b1);
198  high_prod = vec_msum((Packet8i) a1, (Packet8i) bswap, p4i_ZERO);
199  high_prod = (Packet4i) vec_sl((Packet4ui) high_prod, (Packet4ui) p4i_MINUS16);
200  prod = vec_add( low_prod, high_prod );
201
202  // NOR the product and select only the negative elements according to the sign mask
203  prod_ = vec_nor(prod, prod);
204  prod_ = vec_sel(p4i_ZERO, prod_, sgn);
205
206  // Add 1 to the result to get the negative numbers
207  v1sel = vec_sel(p4i_ZERO, p4i_ONE, sgn);
208  prod_ = vec_add(prod_, v1sel);
209
210  // Merge the results back to the final vector.
211  prod = vec_sel(prod, prod_, sgn);
212
213  return prod;
214}
215*/
216template<> EIGEN_STRONG_INLINE Packet4f pdiv<Packet4f>(const Packet4f& a, const Packet4f& b)
217{
218  Packet4f t, y_0, y_1, res;
219
220  // Altivec does not offer a divide instruction, we have to do a reciprocal approximation
221  y_0 = vec_re(b);
222
223  // Do one Newton-Raphson iteration to get the needed accuracy
224  t   = vec_nmsub(y_0, b, p4f_ONE);
225  y_1 = vec_madd(y_0, t, y_0);
226
227  res = vec_madd(a, y_1, p4f_ZERO);
228  return res;
229}
230
231template<> EIGEN_STRONG_INLINE Packet4i pdiv<Packet4i>(const Packet4i& /*a*/, const Packet4i& /*b*/)
232{ eigen_assert(false && "packet integer division are not supported by AltiVec");
233  return pset1<Packet4i>(0);
234}
235
236// for some weird raisons, it has to be overloaded for packet of integers
237template<> EIGEN_STRONG_INLINE Packet4f pmadd(const Packet4f& a, const Packet4f& b, const Packet4f& c) { return vec_madd(a, b, c); }
238template<> EIGEN_STRONG_INLINE Packet4i pmadd(const Packet4i& a, const Packet4i& b, const Packet4i& c) { return padd(pmul(a,b), c); }
239
240template<> EIGEN_STRONG_INLINE Packet4f pmin<Packet4f>(const Packet4f& a, const Packet4f& b) { return vec_min(a, b); }
241template<> EIGEN_STRONG_INLINE Packet4i pmin<Packet4i>(const Packet4i& a, const Packet4i& b) { return vec_min(a, b); }
242
243template<> EIGEN_STRONG_INLINE Packet4f pmax<Packet4f>(const Packet4f& a, const Packet4f& b) { return vec_max(a, b); }
244template<> EIGEN_STRONG_INLINE Packet4i pmax<Packet4i>(const Packet4i& a, const Packet4i& b) { return vec_max(a, b); }
245
246// Logical Operations are not supported for float, so we have to reinterpret casts using NEON intrinsics
247template<> EIGEN_STRONG_INLINE Packet4f pand<Packet4f>(const Packet4f& a, const Packet4f& b) { return vec_and(a, b); }
248template<> EIGEN_STRONG_INLINE Packet4i pand<Packet4i>(const Packet4i& a, const Packet4i& b) { return vec_and(a, b); }
249
250template<> EIGEN_STRONG_INLINE Packet4f por<Packet4f>(const Packet4f& a, const Packet4f& b) { return vec_or(a, b); }
251template<> EIGEN_STRONG_INLINE Packet4i por<Packet4i>(const Packet4i& a, const Packet4i& b) { return vec_or(a, b); }
252
253template<> EIGEN_STRONG_INLINE Packet4f pxor<Packet4f>(const Packet4f& a, const Packet4f& b) { return vec_xor(a, b); }
254template<> EIGEN_STRONG_INLINE Packet4i pxor<Packet4i>(const Packet4i& a, const Packet4i& b) { return vec_xor(a, b); }
255
256template<> EIGEN_STRONG_INLINE Packet4f pandnot<Packet4f>(const Packet4f& a, const Packet4f& b) { return vec_and(a, vec_nor(b, b)); }
257template<> EIGEN_STRONG_INLINE Packet4i pandnot<Packet4i>(const Packet4i& a, const Packet4i& b) { return vec_and(a, vec_nor(b, b)); }
258
259template<> EIGEN_STRONG_INLINE Packet4f pload<Packet4f>(const float* from) { EIGEN_DEBUG_ALIGNED_LOAD return vec_ld(0, from); }
260template<> EIGEN_STRONG_INLINE Packet4i pload<Packet4i>(const int*     from) { EIGEN_DEBUG_ALIGNED_LOAD return vec_ld(0, from); }
261
262template<> EIGEN_STRONG_INLINE Packet4f ploadu<Packet4f>(const float* from)
263{
264  EIGEN_DEBUG_ALIGNED_LOAD
265  // Taken from http://developer.apple.com/hardwaredrivers/ve/alignment.html
266  Packet16uc MSQ, LSQ;
267  Packet16uc mask;
268  MSQ = vec_ld(0, (unsigned char *)from);          // most significant quadword
269  LSQ = vec_ld(15, (unsigned char *)from);         // least significant quadword
270  mask = vec_lvsl(0, from);                        // create the permute mask
271  return (Packet4f) vec_perm(MSQ, LSQ, mask);           // align the data
272
273}
274template<> EIGEN_STRONG_INLINE Packet4i ploadu<Packet4i>(const int* from)
275{
276  EIGEN_DEBUG_ALIGNED_LOAD
277  // Taken from http://developer.apple.com/hardwaredrivers/ve/alignment.html
278  Packet16uc MSQ, LSQ;
279  Packet16uc mask;
280  MSQ = vec_ld(0, (unsigned char *)from);          // most significant quadword
281  LSQ = vec_ld(15, (unsigned char *)from);         // least significant quadword
282  mask = vec_lvsl(0, from);                        // create the permute mask
283  return (Packet4i) vec_perm(MSQ, LSQ, mask);    // align the data
284}
285
286template<> EIGEN_STRONG_INLINE Packet4f ploaddup<Packet4f>(const float*   from)
287{
288  Packet4f p;
289  if((ptrdiff_t(&from) % 16) == 0)  p = pload<Packet4f>(from);
290  else                              p = ploadu<Packet4f>(from);
291  return vec_perm(p, p, p16uc_DUPLICATE);
292}
293template<> EIGEN_STRONG_INLINE Packet4i ploaddup<Packet4i>(const int*     from)
294{
295  Packet4i p;
296  if((ptrdiff_t(&from) % 16) == 0)  p = pload<Packet4i>(from);
297  else                              p = ploadu<Packet4i>(from);
298  return vec_perm(p, p, p16uc_DUPLICATE);
299}
300
301template<> EIGEN_STRONG_INLINE void pstore<float>(float*   to, const Packet4f& from) { EIGEN_DEBUG_ALIGNED_STORE vec_st(from, 0, to); }
302template<> EIGEN_STRONG_INLINE void pstore<int>(int*       to, const Packet4i& from) { EIGEN_DEBUG_ALIGNED_STORE vec_st(from, 0, to); }
303
304template<> EIGEN_STRONG_INLINE void pstoreu<float>(float*  to, const Packet4f& from)
305{
306  EIGEN_DEBUG_UNALIGNED_STORE
307  // Taken from http://developer.apple.com/hardwaredrivers/ve/alignment.html
308  // Warning: not thread safe!
309  Packet16uc MSQ, LSQ, edges;
310  Packet16uc edgeAlign, align;
311
312  MSQ = vec_ld(0, (unsigned char *)to);                     // most significant quadword
313  LSQ = vec_ld(15, (unsigned char *)to);                    // least significant quadword
314  edgeAlign = vec_lvsl(0, to);                              // permute map to extract edges
315  edges=vec_perm(LSQ,MSQ,edgeAlign);                        // extract the edges
316  align = vec_lvsr( 0, to );                                // permute map to misalign data
317  MSQ = vec_perm(edges,(Packet16uc)from,align);             // misalign the data (MSQ)
318  LSQ = vec_perm((Packet16uc)from,edges,align);             // misalign the data (LSQ)
319  vec_st( LSQ, 15, (unsigned char *)to );                   // Store the LSQ part first
320  vec_st( MSQ, 0, (unsigned char *)to );                    // Store the MSQ part
321}
322template<> EIGEN_STRONG_INLINE void pstoreu<int>(int*      to, const Packet4i& from)
323{
324  EIGEN_DEBUG_UNALIGNED_STORE
325  // Taken from http://developer.apple.com/hardwaredrivers/ve/alignment.html
326  // Warning: not thread safe!
327  Packet16uc MSQ, LSQ, edges;
328  Packet16uc edgeAlign, align;
329
330  MSQ = vec_ld(0, (unsigned char *)to);                     // most significant quadword
331  LSQ = vec_ld(15, (unsigned char *)to);                    // least significant quadword
332  edgeAlign = vec_lvsl(0, to);                              // permute map to extract edges
333  edges=vec_perm(LSQ, MSQ, edgeAlign);                      // extract the edges
334  align = vec_lvsr( 0, to );                                // permute map to misalign data
335  MSQ = vec_perm(edges, (Packet16uc) from, align);          // misalign the data (MSQ)
336  LSQ = vec_perm((Packet16uc) from, edges, align);          // misalign the data (LSQ)
337  vec_st( LSQ, 15, (unsigned char *)to );                   // Store the LSQ part first
338  vec_st( MSQ, 0, (unsigned char *)to );                    // Store the MSQ part
339}
340
341template<> EIGEN_STRONG_INLINE void prefetch<float>(const float* addr) { vec_dstt(addr, DST_CTRL(2,2,32), DST_CHAN); }
342template<> EIGEN_STRONG_INLINE void prefetch<int>(const int*     addr) { vec_dstt(addr, DST_CTRL(2,2,32), DST_CHAN); }
343
344template<> EIGEN_STRONG_INLINE float  pfirst<Packet4f>(const Packet4f& a) { float EIGEN_ALIGN16 x[4]; vec_st(a, 0, x); return x[0]; }
345template<> EIGEN_STRONG_INLINE int    pfirst<Packet4i>(const Packet4i& a) { int   EIGEN_ALIGN16 x[4]; vec_st(a, 0, x); return x[0]; }
346
347template<> EIGEN_STRONG_INLINE Packet4f preverse(const Packet4f& a) { return (Packet4f)vec_perm((Packet16uc)a,(Packet16uc)a, p16uc_REVERSE); }
348template<> EIGEN_STRONG_INLINE Packet4i preverse(const Packet4i& a) { return (Packet4i)vec_perm((Packet16uc)a,(Packet16uc)a, p16uc_REVERSE); }
349
350template<> EIGEN_STRONG_INLINE Packet4f pabs(const Packet4f& a) { return vec_abs(a); }
351template<> EIGEN_STRONG_INLINE Packet4i pabs(const Packet4i& a) { return vec_abs(a); }
352
353template<> EIGEN_STRONG_INLINE float predux<Packet4f>(const Packet4f& a)
354{
355  Packet4f b, sum;
356  b   = (Packet4f) vec_sld(a, a, 8);
357  sum = vec_add(a, b);
358  b   = (Packet4f) vec_sld(sum, sum, 4);
359  sum = vec_add(sum, b);
360  return pfirst(sum);
361}
362
363template<> EIGEN_STRONG_INLINE Packet4f preduxp<Packet4f>(const Packet4f* vecs)
364{
365  Packet4f v[4], sum[4];
366
367  // It's easier and faster to transpose then add as columns
368  // Check: http://www.freevec.org/function/matrix_4x4_transpose_floats for explanation
369  // Do the transpose, first set of moves
370  v[0] = vec_mergeh(vecs[0], vecs[2]);
371  v[1] = vec_mergel(vecs[0], vecs[2]);
372  v[2] = vec_mergeh(vecs[1], vecs[3]);
373  v[3] = vec_mergel(vecs[1], vecs[3]);
374  // Get the resulting vectors
375  sum[0] = vec_mergeh(v[0], v[2]);
376  sum[1] = vec_mergel(v[0], v[2]);
377  sum[2] = vec_mergeh(v[1], v[3]);
378  sum[3] = vec_mergel(v[1], v[3]);
379
380  // Now do the summation:
381  // Lines 0+1
382  sum[0] = vec_add(sum[0], sum[1]);
383  // Lines 2+3
384  sum[1] = vec_add(sum[2], sum[3]);
385  // Add the results
386  sum[0] = vec_add(sum[0], sum[1]);
387
388  return sum[0];
389}
390
391template<> EIGEN_STRONG_INLINE int predux<Packet4i>(const Packet4i& a)
392{
393  Packet4i sum;
394  sum = vec_sums(a, p4i_ZERO);
395  sum = vec_sld(sum, p4i_ZERO, 12);
396  return pfirst(sum);
397}
398
399template<> EIGEN_STRONG_INLINE Packet4i preduxp<Packet4i>(const Packet4i* vecs)
400{
401  Packet4i v[4], sum[4];
402
403  // It's easier and faster to transpose then add as columns
404  // Check: http://www.freevec.org/function/matrix_4x4_transpose_floats for explanation
405  // Do the transpose, first set of moves
406  v[0] = vec_mergeh(vecs[0], vecs[2]);
407  v[1] = vec_mergel(vecs[0], vecs[2]);
408  v[2] = vec_mergeh(vecs[1], vecs[3]);
409  v[3] = vec_mergel(vecs[1], vecs[3]);
410  // Get the resulting vectors
411  sum[0] = vec_mergeh(v[0], v[2]);
412  sum[1] = vec_mergel(v[0], v[2]);
413  sum[2] = vec_mergeh(v[1], v[3]);
414  sum[3] = vec_mergel(v[1], v[3]);
415
416  // Now do the summation:
417  // Lines 0+1
418  sum[0] = vec_add(sum[0], sum[1]);
419  // Lines 2+3
420  sum[1] = vec_add(sum[2], sum[3]);
421  // Add the results
422  sum[0] = vec_add(sum[0], sum[1]);
423
424  return sum[0];
425}
426
427// Other reduction functions:
428// mul
429template<> EIGEN_STRONG_INLINE float predux_mul<Packet4f>(const Packet4f& a)
430{
431  Packet4f prod;
432  prod = pmul(a, (Packet4f)vec_sld(a, a, 8));
433  return pfirst(pmul(prod, (Packet4f)vec_sld(prod, prod, 4)));
434}
435
436template<> EIGEN_STRONG_INLINE int predux_mul<Packet4i>(const Packet4i& a)
437{
438  EIGEN_ALIGN16 int aux[4];
439  pstore(aux, a);
440  return aux[0] * aux[1] * aux[2] * aux[3];
441}
442
443// min
444template<> EIGEN_STRONG_INLINE float predux_min<Packet4f>(const Packet4f& a)
445{
446  Packet4f b, res;
447  b = vec_min(a, vec_sld(a, a, 8));
448  res = vec_min(b, vec_sld(b, b, 4));
449  return pfirst(res);
450}
451
452template<> EIGEN_STRONG_INLINE int predux_min<Packet4i>(const Packet4i& a)
453{
454  Packet4i b, res;
455  b = vec_min(a, vec_sld(a, a, 8));
456  res = vec_min(b, vec_sld(b, b, 4));
457  return pfirst(res);
458}
459
460// max
461template<> EIGEN_STRONG_INLINE float predux_max<Packet4f>(const Packet4f& a)
462{
463  Packet4f b, res;
464  b = vec_max(a, vec_sld(a, a, 8));
465  res = vec_max(b, vec_sld(b, b, 4));
466  return pfirst(res);
467}
468
469template<> EIGEN_STRONG_INLINE int predux_max<Packet4i>(const Packet4i& a)
470{
471  Packet4i b, res;
472  b = vec_max(a, vec_sld(a, a, 8));
473  res = vec_max(b, vec_sld(b, b, 4));
474  return pfirst(res);
475}
476
477template<int Offset>
478struct palign_impl<Offset,Packet4f>
479{
480  static EIGEN_STRONG_INLINE void run(Packet4f& first, const Packet4f& second)
481  {
482    if (Offset!=0)
483      first = vec_sld(first, second, Offset*4);
484  }
485};
486
487template<int Offset>
488struct palign_impl<Offset,Packet4i>
489{
490  static EIGEN_STRONG_INLINE void run(Packet4i& first, const Packet4i& second)
491  {
492    if (Offset!=0)
493      first = vec_sld(first, second, Offset*4);
494  }
495};
496
497} // end namespace internal
498
499} // end namespace Eigen
500
501#endif // EIGEN_PACKET_MATH_ALTIVEC_H
502