Botan: src/block/idea_sse2/idea_sse2.cpp Source File

Botan 1.10.12

- Main Page
- Related Pages
- Namespaces
- Classes
- Files

- File List
- File Members

idea_sse2.cpp
Go to the documentation of this file.
1 /*
2 * IDEA in SSE2
3 * (C) 2009 Jack Lloyd
4 *
5 * Distributed under the terms of the Botan license
6 */
7
8 #include <botan/idea_sse2.h>
9 #include <emmintrin.h>
10
11 namespace Botan {
12
13 namespace {
14
15 inline __m128i mul(__m128i X, u16bit K_16)
16 {
17 const __m128i zeros = _mm_set1_epi16(0);
18 const __m128i ones = _mm_set1_epi16(1);
19
20 const __m128i K = _mm_set1_epi16(K_16);
21
22 const __m128i X_is_zero = _mm_cmpeq_epi16(X, zeros);
23 const __m128i K_is_zero = _mm_cmpeq_epi16(K, zeros);
24
25 const __m128i mul_lo = _mm_mullo_epi16(X, K);
26 const __m128i mul_hi = _mm_mulhi_epu16(X, K);
27
28 __m128i T = _mm_sub_epi16(mul_lo, mul_hi);
29
30 // Unsigned compare; cmp = 1 if mul_lo < mul_hi else 0
31 const __m128i subs = _mm_subs_epu16(mul_hi, mul_lo);
32 const __m128i cmp = _mm_min_epu8(
33 _mm_or_si128(subs, _mm_srli_epi16(subs, 8)), ones);
34
35 T = _mm_add_epi16(T, cmp);
36
37 /* Selection: if X[i] is zero then assign 1-K
38 if K is zero then assign 1-X[i]
39
40 Could if() off value of K_16 for the second, but this gives a
41 constant time implementation which is a nice bonus.
42 */
43
44 T = _mm_or_si128(
45 _mm_andnot_si128(X_is_zero, T),
46 _mm_and_si128(_mm_sub_epi16(ones, K), X_is_zero));
47
48 T = _mm_or_si128(
49 _mm_andnot_si128(K_is_zero, T),
50 _mm_and_si128(_mm_sub_epi16(ones, X), K_is_zero));
51
52 return T;
53 }
54
55 /*
56 * 4x8 matrix transpose
57 *
58 * FIXME: why do I need the extra set of unpack_epi32 here? Inverse in
59 * transpose_out doesn't need it. Something with the shuffle? Removing
60 * that extra unpack could easily save 3-4 cycles per block, and would
61 * also help a lot with register pressure on 32-bit x86
62 */
63 void transpose_in(__m128i& B0, __m128i& B1, __m128i& B2, __m128i& B3)
64 {
65 __m128i T0 = _mm_unpackhi_epi32(B0, B1);
66 __m128i T1 = _mm_unpacklo_epi32(B0, B1);
67 __m128i T2 = _mm_unpackhi_epi32(B2, B3);
68 __m128i T3 = _mm_unpacklo_epi32(B2, B3);
69
70 __m128i T4 = _mm_unpacklo_epi32(T0, T1);
71 __m128i T5 = _mm_unpackhi_epi32(T0, T1);
72 __m128i T6 = _mm_unpacklo_epi32(T2, T3);
73 __m128i T7 = _mm_unpackhi_epi32(T2, T3);
74
75 T0 = _mm_shufflehi_epi16(T4, _MM_SHUFFLE(1, 3, 0, 2));
76 T1 = _mm_shufflehi_epi16(T5, _MM_SHUFFLE(1, 3, 0, 2));
77 T2 = _mm_shufflehi_epi16(T6, _MM_SHUFFLE(1, 3, 0, 2));
78 T3 = _mm_shufflehi_epi16(T7, _MM_SHUFFLE(1, 3, 0, 2));
79
80 T0 = _mm_shufflelo_epi16(T0, _MM_SHUFFLE(1, 3, 0, 2));
81 T1 = _mm_shufflelo_epi16(T1, _MM_SHUFFLE(1, 3, 0, 2));
82 T2 = _mm_shufflelo_epi16(T2, _MM_SHUFFLE(1, 3, 0, 2));
83 T3 = _mm_shufflelo_epi16(T3, _MM_SHUFFLE(1, 3, 0, 2));
84
85 T0 = _mm_shuffle_epi32(T0, _MM_SHUFFLE(3, 1, 2, 0));
86 T1 = _mm_shuffle_epi32(T1, _MM_SHUFFLE(3, 1, 2, 0));
87 T2 = _mm_shuffle_epi32(T2, _MM_SHUFFLE(3, 1, 2, 0));
88 T3 = _mm_shuffle_epi32(T3, _MM_SHUFFLE(3, 1, 2, 0));
89
90 B0 = _mm_unpacklo_epi64(T0, T2);
91 B1 = _mm_unpackhi_epi64(T0, T2);
92 B2 = _mm_unpacklo_epi64(T1, T3);
93 B3 = _mm_unpackhi_epi64(T1, T3);
94 }
95
96 /*
97 * 4x8 matrix transpose (reverse)
98 */
99 void transpose_out(__m128i& B0, __m128i& B1, __m128i& B2, __m128i& B3)
100 {
101 __m128i T0 = _mm_unpacklo_epi64(B0, B1);
102 __m128i T1 = _mm_unpacklo_epi64(B2, B3);
103 __m128i T2 = _mm_unpackhi_epi64(B0, B1);
104 __m128i T3 = _mm_unpackhi_epi64(B2, B3);
105
106 T0 = _mm_shuffle_epi32(T0, _MM_SHUFFLE(3, 1, 2, 0));
107 T1 = _mm_shuffle_epi32(T1, _MM_SHUFFLE(3, 1, 2, 0));
108 T2 = _mm_shuffle_epi32(T2, _MM_SHUFFLE(3, 1, 2, 0));
109 T3 = _mm_shuffle_epi32(T3, _MM_SHUFFLE(3, 1, 2, 0));
110
111 T0 = _mm_shufflehi_epi16(T0, _MM_SHUFFLE(3, 1, 2, 0));
112 T1 = _mm_shufflehi_epi16(T1, _MM_SHUFFLE(3, 1, 2, 0));
113 T2 = _mm_shufflehi_epi16(T2, _MM_SHUFFLE(3, 1, 2, 0));
114 T3 = _mm_shufflehi_epi16(T3, _MM_SHUFFLE(3, 1, 2, 0));
115
116 T0 = _mm_shufflelo_epi16(T0, _MM_SHUFFLE(3, 1, 2, 0));
117 T1 = _mm_shufflelo_epi16(T1, _MM_SHUFFLE(3, 1, 2, 0));
118 T2 = _mm_shufflelo_epi16(T2, _MM_SHUFFLE(3, 1, 2, 0));
119 T3 = _mm_shufflelo_epi16(T3, _MM_SHUFFLE(3, 1, 2, 0));
120
121 B0 = _mm_unpacklo_epi32(T0, T1);
122 B1 = _mm_unpackhi_epi32(T0, T1);
123 B2 = _mm_unpacklo_epi32(T2, T3);
124 B3 = _mm_unpackhi_epi32(T2, T3);
125 }
126
127 /*
128 * IDEA encryption/decryption in SSE2
129 */
130 void idea_op_8(const byte in[64], byte out[64], const u16bit EK[52])
131 {
132 const __m128i* in_mm = reinterpret_cast<const __m128i*>(in);
133
134 __m128i B0 = _mm_loadu_si128(in_mm + 0);
135 __m128i B1 = _mm_loadu_si128(in_mm + 1);
136 __m128i B2 = _mm_loadu_si128(in_mm + 2);
137 __m128i B3 = _mm_loadu_si128(in_mm + 3);
138
139 transpose_in(B0, B1, B2, B3);
140
141 // byte swap
142 B0 = _mm_or_si128(_mm_slli_epi16(B0, 8), _mm_srli_epi16(B0, 8));
143 B1 = _mm_or_si128(_mm_slli_epi16(B1, 8), _mm_srli_epi16(B1, 8));
144 B2 = _mm_or_si128(_mm_slli_epi16(B2, 8), _mm_srli_epi16(B2, 8));
145 B3 = _mm_or_si128(_mm_slli_epi16(B3, 8), _mm_srli_epi16(B3, 8));
146
147 for(size_t i = 0; i != 8; ++i)
148 {
149 B0 = mul(B0, EK[6*i+0]);
150 B1 = _mm_add_epi16(B1, _mm_set1_epi16(EK[6*i+1]));
151 B2 = _mm_add_epi16(B2, _mm_set1_epi16(EK[6*i+2]));
152 B3 = mul(B3, EK[6*i+3]);
153
154 __m128i T0 = B2;
155
156 B2 = _mm_xor_si128(B2, B0);
157 B2 = mul(B2, EK[6*i+4]);
158
159 __m128i T1 = B1;
160
161 B1 = _mm_xor_si128(B1, B3);
162 B1 = _mm_add_epi16(B1, B2);
163 B1 = mul(B1, EK[6*i+5]);
164
165 B2 = _mm_add_epi16(B2, B1);
166
167 B0 = _mm_xor_si128(B0, B1);
168 B1 = _mm_xor_si128(B1, T0);
169 B3 = _mm_xor_si128(B3, B2);
170 B2 = _mm_xor_si128(B2, T1);
171 }
172
173 B0 = mul(B0, EK[48]);
174 B1 = _mm_add_epi16(B1, _mm_set1_epi16(EK[50]));
175 B2 = _mm_add_epi16(B2, _mm_set1_epi16(EK[49]));
176 B3 = mul(B3, EK[51]);
177
178 // byte swap
179 B0 = _mm_or_si128(_mm_slli_epi16(B0, 8), _mm_srli_epi16(B0, 8));
180 B1 = _mm_or_si128(_mm_slli_epi16(B1, 8), _mm_srli_epi16(B1, 8));
181 B2 = _mm_or_si128(_mm_slli_epi16(B2, 8), _mm_srli_epi16(B2, 8));
182 B3 = _mm_or_si128(_mm_slli_epi16(B3, 8), _mm_srli_epi16(B3, 8));
183
184 transpose_out(B0, B2, B1, B3);
185
186 __m128i* out_mm = reinterpret_cast<__m128i*>(out);
187
188 _mm_storeu_si128(out_mm + 0, B0);
189 _mm_storeu_si128(out_mm + 1, B2);
190 _mm_storeu_si128(out_mm + 2, B1);
191 _mm_storeu_si128(out_mm + 3, B3);
192 }
193
194 }
195
196 /*
197 * IDEA Encryption
198 */
199 void IDEA_SSE2::encrypt_n(const byte in[], byte out[], size_t blocks) const
200 {
201 const u16bit* KS = &this->get_EK()[0];
202
203 while(blocks >= 8)
204 {
205 idea_op_8(in, out, KS);
206 in += 8 * BLOCK_SIZE;
207 out += 8 * BLOCK_SIZE;
208 blocks -= 8;
209 }
210
211 if(blocks)
212 IDEA::encrypt_n(in, out, blocks);
213 }
214
215 /*
216 * IDEA Decryption
217 */
218 void IDEA_SSE2::decrypt_n(const byte in[], byte out[], size_t blocks) const
219 {
220 const u16bit* KS = &this->get_DK()[0];
221
222 while(blocks >= 8)
223 {
224 idea_op_8(in, out, KS);
225 in += 8 * BLOCK_SIZE;
226 out += 8 * BLOCK_SIZE;
227 blocks -= 8;
228 }
229
230 if(blocks)
231 IDEA::decrypt_n(in, out, blocks);
232 }
233
234 }
Botan::IDEA_SSE2::encrypt_n
void encrypt_n(const byte in[], byte out[], size_t blocks) const
Definition: idea_sse2.cpp:199
Botan::Block_Cipher_Fixed_Params< 8, 16 >::BLOCK_SIZE
Definition: block_cipher.h:107
Botan::IDEA::get_EK
const SecureVector< u16bit > & get_EK() const
Definition: idea.h:33
Botan::IDEA_SSE2::decrypt_n
void decrypt_n(const byte in[], byte out[], size_t blocks) const
Definition: idea_sse2.cpp:218
Botan::byte
unsigned char byte
Definition: types.h:22
Botan::u16bit
unsigned short u16bit
Definition: types.h:27
Botan::IDEA::decrypt_n
void decrypt_n(const byte in[], byte out[], size_t blocks) const
Definition: idea.cpp:117
Botan
Definition: algo_base.h:14
Botan::IDEA::encrypt_n
void encrypt_n(const byte in[], byte out[], size_t blocks) const
Definition: idea.cpp:109
Botan::IDEA::get_DK
const SecureVector< u16bit > & get_DK() const
Definition: idea.h:38