1 | /* |
2 | * Copyright (c) 2015, Intel Corporation |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without |
5 | * modification, are permitted provided that the following conditions are met: |
6 | * |
7 | * * Redistributions of source code must retain the above copyright notice, |
8 | * this list of conditions and the following disclaimer. |
9 | * * Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * * Neither the name of Intel Corporation nor the names of its contributors |
13 | * may be used to endorse or promote products derived from this software |
14 | * without specific prior written permission. |
15 | * |
16 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
17 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
20 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
26 | * POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
28 | |
29 | /** \file |
30 | * \brief Functions for packing/unpacking arrays. |
31 | */ |
32 | |
33 | #ifndef UTIL_PACK_BITS_H |
34 | #define UTIL_PACK_BITS_H |
35 | |
36 | #include "ue2common.h" |
37 | #include "unaligned.h" |
38 | #include "partial_store.h" |
39 | |
40 | /** |
41 | * \brief Pack bits from an array of 32-bit words into \a out. |
42 | * |
43 | * \param out Output array. Must be large enough to store sum(bits). |
44 | * \param v Input array. |
45 | * \param bits Number of low bits in the corresponding element of \a v to pack. |
46 | * \param elements Size of the \a v and \a bits arrays. |
47 | */ |
48 | static really_inline |
49 | void pack_bits_32(char *out, const u32 *v, const u32 *bits, |
50 | const unsigned int elements); |
51 | |
52 | /** |
53 | * \brief Pack bits from an array of 64-bit words into \a out. |
54 | * |
55 | * \param out Output array. Must be large enough to store sum(bits). |
56 | * \param v Input array. |
57 | * \param bits Number of low bits in the corresponding element of \a v to pack. |
58 | * \param elements Size of the \a v and \a bits arrays. |
59 | */ |
60 | static really_inline |
61 | void pack_bits_64(char *out, const u64a *v, const u32 *bits, |
62 | const unsigned int elements); |
63 | |
64 | /** |
65 | * \brief Unpack bits into an array of 32-bit words according to the counts |
66 | * given. |
67 | * |
68 | * \param v Output array. |
69 | * \param in Packed input array. |
70 | * \param bits Number of bits to unpack into the corresponding element of \a v. |
71 | * \param elements Size of the \a v and \a bits arrays. |
72 | */ |
73 | static really_inline |
74 | void unpack_bits_32(u32 *v, const u8 *in, const u32 *bits, |
75 | const unsigned int elements); |
76 | |
77 | /** |
78 | * \brief Unpack bits into an array of 64-bit words according to the counts |
79 | * given. |
80 | * |
81 | * \param v Output array. |
82 | * \param in Packed input array. |
83 | * \param bits Number of bits to unpack into the corresponding element of \a v. |
84 | * \param elements Size of the \a v and \a bits arrays. |
85 | */ |
86 | static really_inline |
87 | void unpack_bits_64(u64a *v, const u8 *in, const u32 *bits, |
88 | const unsigned int elements); |
89 | |
90 | /* |
91 | * Inline implementations follow. |
92 | */ |
93 | |
94 | static really_inline |
95 | void pack_bits_32(char *out, const u32 *v, const u32 *bits, |
96 | const unsigned int elements) { |
97 | u32 write = 0; // accumulator |
98 | u32 idx = 0; // acc holds this many bits |
99 | |
100 | for (unsigned int i = 0; i < elements; i++) { |
101 | assert(bits[i] <= 32); |
102 | write |= (v[i] << idx); |
103 | idx += bits[i]; |
104 | if (idx >= 32) { |
105 | unaligned_store_u32(out, write); |
106 | out += 4; |
107 | idx -= 32; |
108 | u32 leftover = bits[i] - idx; |
109 | if (leftover == 32) { |
110 | write = 0; |
111 | } else { |
112 | assert(leftover < 32); |
113 | write = v[i] >> leftover; |
114 | } |
115 | } |
116 | } |
117 | |
118 | // There might be a write left over. |
119 | partial_store_u32(out, write, (idx + 7) / 8); |
120 | } |
121 | |
122 | static really_inline |
123 | void pack_bits_64(char *out, const u64a *v, const u32 *bits, |
124 | const unsigned int elements) { |
125 | u64a write = 0; // accumulator |
126 | u32 idx = 0; // acc holds this many bits |
127 | |
128 | for (unsigned int i = 0; i < elements; i++) { |
129 | assert(bits[i] <= 64); |
130 | write |= (v[i] << idx); |
131 | idx += bits[i]; |
132 | if (idx >= 64) { |
133 | unaligned_store_u64a(out, write); |
134 | out += 8; |
135 | idx -= 64; |
136 | u32 leftover = bits[i] - idx; |
137 | if (leftover == 64) { |
138 | write = 0; |
139 | } else { |
140 | assert(leftover < 64); |
141 | write = v[i] >> leftover; |
142 | } |
143 | } |
144 | } |
145 | |
146 | // There might be a write left over. |
147 | DEBUG_PRINTF("partial store of idx=%u\n" , idx); |
148 | partial_store_u64a(out, write, (idx + 7) / 8); |
149 | } |
150 | |
151 | static really_inline |
152 | void unpack_bits_32(u32 *v, const u8 *in, const u32 *bits, |
153 | const unsigned int elements) { |
154 | u32 used = 0; // bits used from *in |
155 | |
156 | for (unsigned int i = 0; i < elements; i++) { |
157 | assert(bits[i] <= 32); |
158 | u32 v_out = 0; // accumulator for v[i] |
159 | u32 b = bits[i]; // bits left to read for v[i] |
160 | u32 vidx = 0; // bits written to v[i] |
161 | |
162 | while (b) { |
163 | u32 read = *in >> used; |
164 | u32 bits_read = 8 - used; |
165 | |
166 | if (b <= bits_read) { |
167 | u32 mask = read & ((1U << b) - 1); |
168 | v_out |= mask << vidx; |
169 | vidx += b; |
170 | used += b; |
171 | b = 0; |
172 | if (used < 8) { |
173 | continue; // more from this *in |
174 | } |
175 | } else { |
176 | v_out |= read << vidx; |
177 | vidx += bits_read; |
178 | b -= bits_read; |
179 | } |
180 | |
181 | used = 0; |
182 | in++; |
183 | } |
184 | |
185 | v[i] = v_out; |
186 | } |
187 | } |
188 | |
189 | static really_inline |
190 | void unpack_bits_64(u64a *v, const u8 *in, const u32 *bits, |
191 | const unsigned int elements) { |
192 | u32 used = 0; // bits used from *in |
193 | |
194 | for (unsigned int i = 0; i < elements; i++) { |
195 | assert(bits[i] <= 64); |
196 | u64a v_out = 0; // accumulator for v[i] |
197 | u32 b = bits[i]; // bits left to read for v[i] |
198 | u32 vidx = 0; // bits written to v[i] |
199 | |
200 | while (b) { |
201 | u64a read = *in >> used; |
202 | u32 bits_read = 8 - used; |
203 | |
204 | if (b <= bits_read) { |
205 | u64a mask = read & ((1U << b) - 1); |
206 | v_out |= mask << vidx; |
207 | vidx += b; |
208 | used += b; |
209 | b = 0; |
210 | if (used < 8) { |
211 | continue; // more from this *in |
212 | } |
213 | } else { |
214 | v_out |= read << vidx; |
215 | vidx += bits_read; |
216 | b -= bits_read; |
217 | } |
218 | |
219 | used = 0; |
220 | in++; |
221 | } |
222 | |
223 | v[i] = v_out; |
224 | } |
225 | } |
226 | |
227 | #endif // UTIL_PACK_BITS_H |
228 | |