Vector Optimized Library of Kernels  3.1.2
Architecture-tuned implementations of math kernels
volk_32u_reverse_32u.h
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1 /* -*- c++ -*- */
2 /*
3  * Copyright 2018 Free Software Foundation, Inc.
4  *
5  * This file is part of VOLK
6  *
7  * SPDX-License-Identifier: LGPL-3.0-or-later
8  */
9 
30 #ifndef INCLUDED_VOLK_32u_REVERSE_32u_U_H
31 
32 // Idea from "Bit Twiddling Hacks", which dedicates this method to public domain
33 // http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable
34 static const unsigned char BitReverseTable256[] = {
35  0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0,
36  0x70, 0xF0, 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, 0x18, 0x98, 0x58, 0xD8,
37  0x38, 0xB8, 0x78, 0xF8, 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, 0x14, 0x94,
38  0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4, 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC,
39  0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC, 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2,
40  0x62, 0xE2, 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2, 0x0A, 0x8A, 0x4A, 0xCA,
41  0x2A, 0xAA, 0x6A, 0xEA, 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA, 0x06, 0x86,
42  0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
43  0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE,
44  0x7E, 0xFE, 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, 0x11, 0x91, 0x51, 0xD1,
45  0x31, 0xB1, 0x71, 0xF1, 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, 0x19, 0x99,
46  0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9, 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5,
47  0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5, 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD,
48  0x6D, 0xED, 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD, 0x03, 0x83, 0x43, 0xC3,
49  0x23, 0xA3, 0x63, 0xE3, 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3, 0x0B, 0x8B,
50  0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
51  0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7,
52  0x77, 0xF7, 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, 0x1F, 0x9F, 0x5F, 0xDF,
53  0x3F, 0xBF, 0x7F, 0xFF
54 };
55 #ifdef LV_HAVE_GENERIC
56 static inline void
57 volk_32u_reverse_32u_generic(uint32_t* out, const uint32_t* in, unsigned int num_points)
58 {
59  const uint32_t* in_ptr = in;
60  uint32_t* out_ptr = out;
61  unsigned int number = 0;
62  for (; number < num_points; ++number) {
63  *out_ptr = (((*in_ptr >> 31) & 1) << 0) | (((*in_ptr >> 30) & 1) << 1) |
64  (((*in_ptr >> 29) & 1) << 2) | (((*in_ptr >> 28) & 1) << 3) |
65  (((*in_ptr >> 27) & 1) << 4) | (((*in_ptr >> 26) & 1) << 5) |
66  (((*in_ptr >> 25) & 1) << 6) | (((*in_ptr >> 24) & 1) << 7) |
67  (((*in_ptr >> 23) & 1) << 8) | (((*in_ptr >> 22) & 1) << 9) |
68  (((*in_ptr >> 21) & 1) << 10) | (((*in_ptr >> 20) & 1) << 11) |
69  (((*in_ptr >> 19) & 1) << 12) | (((*in_ptr >> 18) & 1) << 13) |
70  (((*in_ptr >> 17) & 1) << 14) | (((*in_ptr >> 16) & 1) << 15) |
71  (((*in_ptr >> 15) & 1) << 16) | (((*in_ptr >> 14) & 1) << 17) |
72  (((*in_ptr >> 13) & 1) << 18) | (((*in_ptr >> 12) & 1) << 19) |
73  (((*in_ptr >> 11) & 1) << 20) | (((*in_ptr >> 10) & 1) << 21) |
74  (((*in_ptr >> 9) & 1) << 22) | (((*in_ptr >> 8) & 1) << 23) |
75  (((*in_ptr >> 7) & 1) << 24) | (((*in_ptr >> 6) & 1) << 25) |
76  (((*in_ptr >> 5) & 1) << 26) | (((*in_ptr >> 4) & 1) << 27) |
77  (((*in_ptr >> 3) & 1) << 28) | (((*in_ptr >> 2) & 1) << 29) |
78  (((*in_ptr >> 1) & 1) << 30) | (((*in_ptr >> 0) & 1) << 31);
79  ++in_ptr;
80  ++out_ptr;
81  }
82 }
83 #endif /* LV_HAVE_GENERIC */
84 
85 #ifdef LV_HAVE_GENERIC
86 static inline void volk_32u_reverse_32u_byte_shuffle(uint32_t* out,
87  const uint32_t* in,
88  unsigned int num_points)
89 {
90  const uint32_t* in_ptr = in;
91  uint32_t* out_ptr = out;
92  unsigned int number = 0;
93  for (; number < num_points; ++number) {
94  const uint8_t* in8 = (const uint8_t*)in_ptr;
95  uint8_t* out8 = (uint8_t*)out_ptr;
96 
97  out8[3] = (((in8[0] >> 7) & 1) << 0) | (((in8[0] >> 6) & 1) << 1) |
98  (((in8[0] >> 5) & 1) << 2) | (((in8[0] >> 4) & 1) << 3) |
99  (((in8[0] >> 3) & 1) << 4) | (((in8[0] >> 2) & 1) << 5) |
100  (((in8[0] >> 1) & 1) << 6) | (((in8[0] >> 0) & 1) << 7);
101 
102  out8[2] = (((in8[1] >> 7) & 1) << 0) | (((in8[1] >> 6) & 1) << 1) |
103  (((in8[1] >> 5) & 1) << 2) | (((in8[1] >> 4) & 1) << 3) |
104  (((in8[1] >> 3) & 1) << 4) | (((in8[1] >> 2) & 1) << 5) |
105  (((in8[1] >> 1) & 1) << 6) | (((in8[1] >> 0) & 1) << 7);
106 
107  out8[1] = (((in8[2] >> 7) & 1) << 0) | (((in8[2] >> 6) & 1) << 1) |
108  (((in8[2] >> 5) & 1) << 2) | (((in8[2] >> 4) & 1) << 3) |
109  (((in8[2] >> 3) & 1) << 4) | (((in8[2] >> 2) & 1) << 5) |
110  (((in8[2] >> 1) & 1) << 6) | (((in8[2] >> 0) & 1) << 7);
111 
112  out8[0] = (((in8[3] >> 7) & 1) << 0) | (((in8[3] >> 6) & 1) << 1) |
113  (((in8[3] >> 5) & 1) << 2) | (((in8[3] >> 4) & 1) << 3) |
114  (((in8[3] >> 3) & 1) << 4) | (((in8[3] >> 2) & 1) << 5) |
115  (((in8[3] >> 1) & 1) << 6) | (((in8[3] >> 0) & 1) << 7);
116  ++in_ptr;
117  ++out_ptr;
118  }
119 }
120 #endif /* LV_HAVE_GENERIC */
121 
122 // Idea from "Bit Twiddling Hacks", which dedicates this method to public domain
123 // http://graphics.stanford.edu/~seander/bithacks.html#BitReverseTable
124 #ifdef LV_HAVE_GENERIC
125 static inline void
126 volk_32u_reverse_32u_lut(uint32_t* out, const uint32_t* in, unsigned int num_points)
127 {
128  const uint32_t* in_ptr = in;
129  uint32_t* out_ptr = out;
130  unsigned int number = 0;
131  for (; number < num_points; ++number) {
132  *out_ptr = ((uint32_t)BitReverseTable256[*in_ptr & 0xff] << 24) |
133  (BitReverseTable256[(*in_ptr >> 8) & 0xff] << 16) |
134  (BitReverseTable256[(*in_ptr >> 16) & 0xff] << 8) |
135  (BitReverseTable256[(*in_ptr >> 24) & 0xff]);
136  ++in_ptr;
137  ++out_ptr;
138  }
139 }
140 #endif /* LV_HAVE_GENERIC */
141 
142 // Single-Byte code from "Bit Twiddling Hacks", which dedicates this method to public
143 // domain http://graphics.stanford.edu/~seander/bithacks.html#ReverseByteWith64Bits
144 #ifdef LV_HAVE_GENERIC
145 static inline void
146 volk_32u_reverse_32u_2001magic(uint32_t* out, const uint32_t* in, unsigned int num_points)
147 {
148  const uint32_t* in_ptr = in;
149  uint32_t* out_ptr = out;
150  const uint8_t* in8;
151  uint8_t* out8;
152  unsigned int number = 0;
153  for (; number < num_points; ++number) {
154  in8 = (const uint8_t*)in_ptr;
155  out8 = (uint8_t*)out_ptr;
156  out8[3] = ((in8[0] * 0x80200802ULL) & 0x0884422110ULL) * 0x0101010101ULL >> 32;
157  out8[2] = ((in8[1] * 0x80200802ULL) & 0x0884422110ULL) * 0x0101010101ULL >> 32;
158  out8[1] = ((in8[2] * 0x80200802ULL) & 0x0884422110ULL) * 0x0101010101ULL >> 32;
159  out8[0] = ((in8[3] * 0x80200802ULL) & 0x0884422110ULL) * 0x0101010101ULL >> 32;
160  ++in_ptr;
161  ++out_ptr;
162  }
163 }
164 #endif /* LV_HAVE_GENERIC */
165 
166 #ifdef LV_HAVE_GENERIC
167 // Current gr-pager implementation
168 static inline void
169 volk_32u_reverse_32u_1972magic(uint32_t* out, const uint32_t* in, unsigned int num_points)
170 {
171  const uint32_t* in_ptr = in;
172  uint32_t* out_ptr = out;
173  const uint8_t* in8;
174  uint8_t* out8;
175  unsigned int number = 0;
176  for (; number < num_points; ++number) {
177  in8 = (const uint8_t*)in_ptr;
178  out8 = (uint8_t*)out_ptr;
179  out8[3] = (in8[0] * 0x0202020202ULL & 0x010884422010ULL) % 1023;
180  out8[2] = (in8[1] * 0x0202020202ULL & 0x010884422010ULL) % 1023;
181  out8[1] = (in8[2] * 0x0202020202ULL & 0x010884422010ULL) % 1023;
182  out8[0] = (in8[3] * 0x0202020202ULL & 0x010884422010ULL) % 1023;
183  ++in_ptr;
184  ++out_ptr;
185  }
186 }
187 #endif /* LV_HAVE_GENERIC */
188 
189 // After lengthy thought and quite a bit of whiteboarding:
190 #ifdef LV_HAVE_GENERIC
191 static inline void volk_32u_reverse_32u_bintree_permute_top_down(uint32_t* out,
192  const uint32_t* in,
193  unsigned int num_points)
194 {
195  const uint32_t* in_ptr = in;
196  uint32_t* out_ptr = out;
197  unsigned int number = 0;
198  for (; number < num_points; ++number) {
199  uint32_t tmp = *in_ptr;
200  /* permute uint16:
201  The idea is to simply shift the lower 16 bit up, and the upper 16 bit down.
202  */
203  tmp = (tmp << 16) | (tmp >> 16);
204  /* permute bytes:
205  shift up by 1 B first, then only consider even bytes, and OR with the unshifted
206  even bytes
207  */
208  tmp = ((tmp & (0xFF | 0xFF << 16)) << 8) | ((tmp >> 8) & (0xFF | 0xFF << 16));
209  /* permute 4bit tuples:
210  Same idea, but the "consideration" mask expression becomes unwieldy
211  */
212  tmp = ((tmp & (0xF | 0xF << 8 | 0xF << 16 | 0xF << 24)) << 4) |
213  ((tmp >> 4) & (0xF | 0xF << 8 | 0xF << 16 | 0xF << 24));
214  /* permute 2bit tuples:
215  Here, we collapsed the "consideration" mask to a simple hexmask: 0b0011 =
216  3; we need those every 4b, which coincides with a hex digit!
217  */
218  tmp = ((tmp & (0x33333333)) << 2) | ((tmp >> 2) & (0x33333333));
219  /* permute odd/even:
220  0x01 = 0x1; we need these every 2b, which works out: 0x01 | (0x01 << 2) =
221  0x05!
222  */
223  tmp = ((tmp & (0x55555555)) << 1) | ((tmp >> 1) & (0x55555555));
224 
225  *out_ptr = tmp;
226  ++in_ptr;
227  ++out_ptr;
228  }
229 }
230 #endif /* LV_HAVE_GENERIC */
231 #ifdef LV_HAVE_GENERIC
232 static inline void volk_32u_reverse_32u_bintree_permute_bottom_up(uint32_t* out,
233  const uint32_t* in,
234  unsigned int num_points)
235 {
236  // same stuff as top_down, inverted order (permutation matrices don't care, you know!)
237  const uint32_t* in_ptr = in;
238  uint32_t* out_ptr = out;
239  unsigned int number = 0;
240  for (; number < num_points; ++number) {
241  uint32_t tmp = *in_ptr;
242  tmp = ((tmp & (0x55555555)) << 1) | ((tmp >> 1) & (0x55555555));
243  tmp = ((tmp & (0x33333333)) << 2) | ((tmp >> 2) & (0x33333333));
244  tmp = ((tmp & (0xF | 0xF << 8 | 0xF << 16 | 0xF << 24)) << 4) |
245  ((tmp >> 4) & (0xF | 0xF << 8 | 0xF << 16 | 0xF << 24));
246  tmp = ((tmp & (0xFF | 0xFF << 16)) << 8) | ((tmp >> 8) & (0xFF | 0xFF << 16));
247  tmp = (tmp << 16) | (tmp >> 16);
248 
249  *out_ptr = tmp;
250  ++in_ptr;
251  ++out_ptr;
252  }
253 }
254 #endif /* LV_HAVE_GENERIC */
255 
256 #ifdef LV_HAVE_NEONV8
257 #include <arm_neon.h>
258 
259 static inline void
260 volk_32u_reverse_32u_neonv8(uint32_t* out, const uint32_t* in, unsigned int num_points)
261 {
262  const uint32_t* in_ptr = in;
263  uint32_t* out_ptr = out;
264 
265  const uint8x16_t idx = { 3, 2, 1, 0, 7, 6, 5, 4, 11, 10, 9, 8, 15, 14, 13, 12 };
266 
267  const unsigned int quarterPoints = num_points / 4;
268  unsigned int number = 0;
269  for (; number < quarterPoints; ++number) {
270  __VOLK_PREFETCH(in_ptr + 4);
271  uint32x4_t x = vld1q_u32(in_ptr);
272  uint32x4_t z =
273  vreinterpretq_u32_u8(vqtbl1q_u8(vrbitq_u8(vreinterpretq_u8_u32(x)), idx));
274  vst1q_u32(out_ptr, z);
275  in_ptr += 4;
276  out_ptr += 4;
277  }
278  number = quarterPoints * 4;
279  for (; number < num_points; ++number) {
280  *out_ptr = ((uint32_t)BitReverseTable256[*in_ptr & 0xff] << 24) |
281  (BitReverseTable256[(*in_ptr >> 8) & 0xff] << 16) |
282  (BitReverseTable256[(*in_ptr >> 16) & 0xff] << 8) |
283  (BitReverseTable256[(*in_ptr >> 24) & 0xff]);
284  ++in_ptr;
285  ++out_ptr;
286  }
287 }
288 
289 #endif /* LV_HAVE_NEONV8 */
290 
291 #ifdef LV_HAVE_NEON
292 #include <arm_neon.h>
293 
294 #if defined(__aarch64__)
295 #define DO_RBIT \
296  __VOLK_ASM("rbit %w[result], %w[value]" \
297  : [result] "=r"(*out_ptr) \
298  : [value] "r"(*in_ptr) \
299  :); \
300  in_ptr++; \
301  out_ptr++;
302 #else
303 #define DO_RBIT \
304  __VOLK_ASM("rbit %[result], %[value]" \
305  : [result] "=r"(*out_ptr) \
306  : [value] "r"(*in_ptr) \
307  :); \
308  in_ptr++; \
309  out_ptr++;
310 #endif
311 
312 static inline void
313 volk_32u_reverse_32u_arm(uint32_t* out, const uint32_t* in, unsigned int num_points)
314 {
315 
316  const uint32_t* in_ptr = in;
317  uint32_t* out_ptr = out;
318  const unsigned int eighthPoints = num_points / 8;
319  unsigned int number = 0;
320  for (; number < eighthPoints; ++number) {
321  __VOLK_PREFETCH(in_ptr + 8);
322  DO_RBIT;
323  DO_RBIT;
324  DO_RBIT;
325  DO_RBIT;
326  DO_RBIT;
327  DO_RBIT;
328  DO_RBIT;
329  DO_RBIT;
330  }
331  number = eighthPoints * 8;
332  for (; number < num_points; ++number) {
333  DO_RBIT;
334  }
335 }
336 #undef DO_RBIT
337 #endif /* LV_HAVE_NEON */
338 
339 
340 #endif /* INCLUDED_volk_32u_reverse_32u_u_H */
static void volk_32u_reverse_32u_generic(uint32_t *out, const uint32_t *in, unsigned int num_points)
Definition: volk_32u_reverse_32u.h:57
static void volk_32u_reverse_32u_byte_shuffle(uint32_t *out, const uint32_t *in, unsigned int num_points)
Definition: volk_32u_reverse_32u.h:86
static void volk_32u_reverse_32u_arm(uint32_t *out, const uint32_t *in, unsigned int num_points)
Definition: volk_32u_reverse_32u.h:313
static const unsigned char BitReverseTable256[]
Definition: volk_32u_reverse_32u.h:34
#define DO_RBIT
Definition: volk_32u_reverse_32u.h:303
#define __VOLK_PREFETCH(addr)
Definition: volk_common.h:68
static void volk_32u_reverse_32u_bintree_permute_bottom_up(uint32_t *out, const uint32_t *in, unsigned int num_points)
Definition: volk_32u_reverse_32u.h:232
static void volk_32u_reverse_32u_bintree_permute_top_down(uint32_t *out, const uint32_t *in, unsigned int num_points)
Definition: volk_32u_reverse_32u.h:191
static void volk_32u_reverse_32u_lut(uint32_t *out, const uint32_t *in, unsigned int num_points)
Definition: volk_32u_reverse_32u.h:126
static void volk_32u_reverse_32u_1972magic(uint32_t *out, const uint32_t *in, unsigned int num_points)
Definition: volk_32u_reverse_32u.h:169
static void volk_32u_reverse_32u_2001magic(uint32_t *out, const uint32_t *in, unsigned int num_points)
Definition: volk_32u_reverse_32u.h:146