Coverage Report

Created: 2023-06-08 06:41

/src/openssl/include/crypto/md32_common.h
Line
Count
Source (jump to first uncovered line)
1
/*
2
 * Copyright 1999-2022 The OpenSSL Project Authors. All Rights Reserved.
3
 *
4
 * Licensed under the Apache License 2.0 (the "License").  You may not use
5
 * this file except in compliance with the License.  You can obtain a copy
6
 * in the file LICENSE in the source distribution or at
7
 * https://www.openssl.org/source/license.html
8
 */
9
10
/*-
11
 * This is a generic 32 bit "collector" for message digest algorithms.
12
 * Whenever needed it collects input character stream into chunks of
13
 * 32 bit values and invokes a block function that performs actual hash
14
 * calculations.
15
 *
16
 * Porting guide.
17
 *
18
 * Obligatory macros:
19
 *
20
 * DATA_ORDER_IS_BIG_ENDIAN or DATA_ORDER_IS_LITTLE_ENDIAN
21
 *      this macro defines byte order of input stream.
22
 * HASH_CBLOCK
23
 *      size of a unit chunk HASH_BLOCK operates on.
24
 * HASH_LONG
25
 *      has to be at least 32 bit wide.
26
 * HASH_CTX
27
 *      context structure that at least contains following
28
 *      members:
29
 *              typedef struct {
30
 *                      ...
31
 *                      HASH_LONG       Nl,Nh;
32
 *                      either {
33
 *                      HASH_LONG       data[HASH_LBLOCK];
34
 *                      unsigned char   data[HASH_CBLOCK];
35
 *                      };
36
 *                      unsigned int    num;
37
 *                      ...
38
 *                      } HASH_CTX;
39
 *      data[] vector is expected to be zeroed upon first call to
40
 *      HASH_UPDATE.
41
 * HASH_UPDATE
42
 *      name of "Update" function, implemented here.
43
 * HASH_TRANSFORM
44
 *      name of "Transform" function, implemented here.
45
 * HASH_FINAL
46
 *      name of "Final" function, implemented here.
47
 * HASH_BLOCK_DATA_ORDER
48
 *      name of "block" function capable of treating *unaligned* input
49
 *      message in original (data) byte order, implemented externally.
50
 * HASH_MAKE_STRING
51
 *      macro converting context variables to an ASCII hash string.
52
 *
53
 * MD5 example:
54
 *
55
 *      #define DATA_ORDER_IS_LITTLE_ENDIAN
56
 *
57
 *      #define HASH_LONG               MD5_LONG
58
 *      #define HASH_CTX                MD5_CTX
59
 *      #define HASH_CBLOCK             MD5_CBLOCK
60
 *      #define HASH_UPDATE             MD5_Update
61
 *      #define HASH_TRANSFORM          MD5_Transform
62
 *      #define HASH_FINAL              MD5_Final
63
 *      #define HASH_BLOCK_DATA_ORDER   md5_block_data_order
64
 */
65
66
#ifndef OSSL_CRYPTO_MD32_COMMON_H
67
# define OSSL_CRYPTO_MD32_COMMON_H
68
# pragma once
69
70
# include <openssl/crypto.h>
71
72
# if !defined(DATA_ORDER_IS_BIG_ENDIAN) && !defined(DATA_ORDER_IS_LITTLE_ENDIAN)
73
#  error "DATA_ORDER must be defined!"
74
# endif
75
76
# ifndef HASH_CBLOCK
77
#  error "HASH_CBLOCK must be defined!"
78
# endif
79
# ifndef HASH_LONG
80
#  error "HASH_LONG must be defined!"
81
# endif
82
# ifndef HASH_CTX
83
#  error "HASH_CTX must be defined!"
84
# endif
85
86
# ifndef HASH_UPDATE
87
#  error "HASH_UPDATE must be defined!"
88
# endif
89
# ifndef HASH_TRANSFORM
90
#  error "HASH_TRANSFORM must be defined!"
91
# endif
92
# ifndef HASH_FINAL
93
#  error "HASH_FINAL must be defined!"
94
# endif
95
96
# ifndef HASH_BLOCK_DATA_ORDER
97
#  error "HASH_BLOCK_DATA_ORDER must be defined!"
98
# endif
99
100
0
# define ROTATE(a,n)     (((a)<<(n))|(((a)&0xffffffff)>>(32-(n))))
101
102
#ifndef PEDANTIC
103
# if defined(__GNUC__) && __GNUC__>=2 && \
104
     !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM)
105
#  if defined(__riscv_zbb) || defined(__riscv_zbkb)
106
#   if __riscv_xlen == 64
107
#   undef ROTATE
108
#   define ROTATE(x, n) ({ MD32_REG_T ret;            \
109
                       asm ("roriw %0, %1, %2"        \
110
                       : "=r"(ret)                    \
111
                       : "r"(x), "i"(32 - (n))); ret;})
112
#   endif
113
#   if __riscv_xlen == 32
114
#   undef ROTATE
115
#   define ROTATE(x, n) ({ MD32_REG_T ret;            \
116
                       asm ("rori %0, %1, %2"         \
117
                       : "=r"(ret)                    \
118
                       : "r"(x), "i"(32 - (n))); ret;})
119
#   endif
120
#  endif
121
# endif
122
#endif
123
124
# if defined(DATA_ORDER_IS_BIG_ENDIAN)
125
126
0
#  define HOST_c2l(c,l)  (l =(((unsigned long)(*((c)++)))<<24),          \
127
0
                         l|=(((unsigned long)(*((c)++)))<<16),          \
128
0
                         l|=(((unsigned long)(*((c)++)))<< 8),          \
129
0
                         l|=(((unsigned long)(*((c)++)))    )           )
130
728k
#  define HOST_l2c(l,c)  (*((c)++)=(unsigned char)(((l)>>24)&0xff),      \
131
728k
                         *((c)++)=(unsigned char)(((l)>>16)&0xff),      \
132
728k
                         *((c)++)=(unsigned char)(((l)>> 8)&0xff),      \
133
728k
                         *((c)++)=(unsigned char)(((l)    )&0xff),      \
134
728k
                         l)
135
136
# elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
137
138
0
#  define HOST_c2l(c,l)  (l =(((unsigned long)(*((c)++)))    ),          \
139
0
                         l|=(((unsigned long)(*((c)++)))<< 8),          \
140
0
                         l|=(((unsigned long)(*((c)++)))<<16),          \
141
0
                         l|=(((unsigned long)(*((c)++)))<<24)           )
142
123k
#  define HOST_l2c(l,c)  (*((c)++)=(unsigned char)(((l)    )&0xff),      \
143
123k
                         *((c)++)=(unsigned char)(((l)>> 8)&0xff),      \
144
123k
                         *((c)++)=(unsigned char)(((l)>>16)&0xff),      \
145
123k
                         *((c)++)=(unsigned char)(((l)>>24)&0xff),      \
146
123k
                         l)
147
148
# endif
149
150
/*
151
 * Time for some action :-)
152
 */
153
154
int HASH_UPDATE(HASH_CTX *c, const void *data_, size_t len)
155
150k
{
156
150k
    const unsigned char *data = data_;
157
150k
    unsigned char *p;
158
150k
    HASH_LONG l;
159
150k
    size_t n;
160
161
150k
    if (len == 0)
162
0
        return 1;
163
164
150k
    l = (c->Nl + (((HASH_LONG) len) << 3)) & 0xffffffffUL;
165
150k
    if (l < c->Nl)              /* overflow */
166
0
        c->Nh++;
167
150k
    c->Nh += (HASH_LONG) (len >> 29); /* might cause compiler warning on
168
                                       * 16-bit */
169
150k
    c->Nl = l;
170
171
150k
    n = c->num;
172
150k
    if (n != 0) {
173
45.6k
        p = (unsigned char *)c->data;
174
175
45.6k
        if (len >= HASH_CBLOCK || len + n >= HASH_CBLOCK) {
176
20.9k
            memcpy(p + n, data, HASH_CBLOCK - n);
177
20.9k
            HASH_BLOCK_DATA_ORDER(c, p, 1);
178
20.9k
            n = HASH_CBLOCK - n;
179
20.9k
            data += n;
180
20.9k
            len -= n;
181
20.9k
            c->num = 0;
182
            /*
183
             * We use memset rather than OPENSSL_cleanse() here deliberately.
184
             * Using OPENSSL_cleanse() here could be a performance issue. It
185
             * will get properly cleansed on finalisation so this isn't a
186
             * security problem.
187
             */
188
20.9k
            memset(p, 0, HASH_CBLOCK); /* keep it zeroed */
189
24.7k
        } else {
190
24.7k
            memcpy(p + n, data, len);
191
24.7k
            c->num += (unsigned int)len;
192
24.7k
            return 1;
193
24.7k
        }
194
45.6k
    }
195
196
126k
    n = len / HASH_CBLOCK;
197
126k
    if (n > 0) {
198
24.2k
        HASH_BLOCK_DATA_ORDER(c, data, n);
199
24.2k
        n *= HASH_CBLOCK;
200
24.2k
        data += n;
201
24.2k
        len -= n;
202
24.2k
    }
203
204
126k
    if (len != 0) {
205
111k
        p = (unsigned char *)c->data;
206
111k
        c->num = (unsigned int)len;
207
111k
        memcpy(p, data, len);
208
111k
    }
209
126k
    return 1;
210
150k
}
SHA1_Update
Line
Count
Source
155
39.9k
{
156
39.9k
    const unsigned char *data = data_;
157
39.9k
    unsigned char *p;
158
39.9k
    HASH_LONG l;
159
39.9k
    size_t n;
160
161
39.9k
    if (len == 0)
162
0
        return 1;
163
164
39.9k
    l = (c->Nl + (((HASH_LONG) len) << 3)) & 0xffffffffUL;
165
39.9k
    if (l < c->Nl)              /* overflow */
166
0
        c->Nh++;
167
39.9k
    c->Nh += (HASH_LONG) (len >> 29); /* might cause compiler warning on
168
                                       * 16-bit */
169
39.9k
    c->Nl = l;
170
171
39.9k
    n = c->num;
172
39.9k
    if (n != 0) {
173
15.8k
        p = (unsigned char *)c->data;
174
175
15.8k
        if (len >= HASH_CBLOCK || len + n >= HASH_CBLOCK) {
176
7.70k
            memcpy(p + n, data, HASH_CBLOCK - n);
177
7.70k
            HASH_BLOCK_DATA_ORDER(c, p, 1);
178
7.70k
            n = HASH_CBLOCK - n;
179
7.70k
            data += n;
180
7.70k
            len -= n;
181
7.70k
            c->num = 0;
182
            /*
183
             * We use memset rather than OPENSSL_cleanse() here deliberately.
184
             * Using OPENSSL_cleanse() here could be a performance issue. It
185
             * will get properly cleansed on finalisation so this isn't a
186
             * security problem.
187
             */
188
7.70k
            memset(p, 0, HASH_CBLOCK); /* keep it zeroed */
189
8.09k
        } else {
190
8.09k
            memcpy(p + n, data, len);
191
8.09k
            c->num += (unsigned int)len;
192
8.09k
            return 1;
193
8.09k
        }
194
15.8k
    }
195
196
31.8k
    n = len / HASH_CBLOCK;
197
31.8k
    if (n > 0) {
198
7.35k
        HASH_BLOCK_DATA_ORDER(c, data, n);
199
7.35k
        n *= HASH_CBLOCK;
200
7.35k
        data += n;
201
7.35k
        len -= n;
202
7.35k
    }
203
204
31.8k
    if (len != 0) {
205
28.7k
        p = (unsigned char *)c->data;
206
28.7k
        c->num = (unsigned int)len;
207
28.7k
        memcpy(p, data, len);
208
28.7k
    }
209
31.8k
    return 1;
210
39.9k
}
SHA256_Update
Line
Count
Source
155
83.0k
{
156
83.0k
    const unsigned char *data = data_;
157
83.0k
    unsigned char *p;
158
83.0k
    HASH_LONG l;
159
83.0k
    size_t n;
160
161
83.0k
    if (len == 0)
162
0
        return 1;
163
164
83.0k
    l = (c->Nl + (((HASH_LONG) len) << 3)) & 0xffffffffUL;
165
83.0k
    if (l < c->Nl)              /* overflow */
166
0
        c->Nh++;
167
83.0k
    c->Nh += (HASH_LONG) (len >> 29); /* might cause compiler warning on
168
                                       * 16-bit */
169
83.0k
    c->Nl = l;
170
171
83.0k
    n = c->num;
172
83.0k
    if (n != 0) {
173
21.8k
        p = (unsigned char *)c->data;
174
175
21.8k
        if (len >= HASH_CBLOCK || len + n >= HASH_CBLOCK) {
176
6.88k
            memcpy(p + n, data, HASH_CBLOCK - n);
177
6.88k
            HASH_BLOCK_DATA_ORDER(c, p, 1);
178
6.88k
            n = HASH_CBLOCK - n;
179
6.88k
            data += n;
180
6.88k
            len -= n;
181
6.88k
            c->num = 0;
182
            /*
183
             * We use memset rather than OPENSSL_cleanse() here deliberately.
184
             * Using OPENSSL_cleanse() here could be a performance issue. It
185
             * will get properly cleansed on finalisation so this isn't a
186
             * security problem.
187
             */
188
6.88k
            memset(p, 0, HASH_CBLOCK); /* keep it zeroed */
189
14.9k
        } else {
190
14.9k
            memcpy(p + n, data, len);
191
14.9k
            c->num += (unsigned int)len;
192
14.9k
            return 1;
193
14.9k
        }
194
21.8k
    }
195
196
68.0k
    n = len / HASH_CBLOCK;
197
68.0k
    if (n > 0) {
198
12.7k
        HASH_BLOCK_DATA_ORDER(c, data, n);
199
12.7k
        n *= HASH_CBLOCK;
200
12.7k
        data += n;
201
12.7k
        len -= n;
202
12.7k
    }
203
204
68.0k
    if (len != 0) {
205
59.5k
        p = (unsigned char *)c->data;
206
59.5k
        c->num = (unsigned int)len;
207
59.5k
        memcpy(p, data, len);
208
59.5k
    }
209
68.0k
    return 1;
210
83.0k
}
Unexecuted instantiation: MD4_Update
MD5_Update
Line
Count
Source
155
27.8k
{
156
27.8k
    const unsigned char *data = data_;
157
27.8k
    unsigned char *p;
158
27.8k
    HASH_LONG l;
159
27.8k
    size_t n;
160
161
27.8k
    if (len == 0)
162
0
        return 1;
163
164
27.8k
    l = (c->Nl + (((HASH_LONG) len) << 3)) & 0xffffffffUL;
165
27.8k
    if (l < c->Nl)              /* overflow */
166
0
        c->Nh++;
167
27.8k
    c->Nh += (HASH_LONG) (len >> 29); /* might cause compiler warning on
168
                                       * 16-bit */
169
27.8k
    c->Nl = l;
170
171
27.8k
    n = c->num;
172
27.8k
    if (n != 0) {
173
8.02k
        p = (unsigned char *)c->data;
174
175
8.02k
        if (len >= HASH_CBLOCK || len + n >= HASH_CBLOCK) {
176
6.33k
            memcpy(p + n, data, HASH_CBLOCK - n);
177
6.33k
            HASH_BLOCK_DATA_ORDER(c, p, 1);
178
6.33k
            n = HASH_CBLOCK - n;
179
6.33k
            data += n;
180
6.33k
            len -= n;
181
6.33k
            c->num = 0;
182
            /*
183
             * We use memset rather than OPENSSL_cleanse() here deliberately.
184
             * Using OPENSSL_cleanse() here could be a performance issue. It
185
             * will get properly cleansed on finalisation so this isn't a
186
             * security problem.
187
             */
188
6.33k
            memset(p, 0, HASH_CBLOCK); /* keep it zeroed */
189
6.33k
        } else {
190
1.68k
            memcpy(p + n, data, len);
191
1.68k
            c->num += (unsigned int)len;
192
1.68k
            return 1;
193
1.68k
        }
194
8.02k
    }
195
196
26.1k
    n = len / HASH_CBLOCK;
197
26.1k
    if (n > 0) {
198
4.14k
        HASH_BLOCK_DATA_ORDER(c, data, n);
199
4.14k
        n *= HASH_CBLOCK;
200
4.14k
        data += n;
201
4.14k
        len -= n;
202
4.14k
    }
203
204
26.1k
    if (len != 0) {
205
23.4k
        p = (unsigned char *)c->data;
206
23.4k
        c->num = (unsigned int)len;
207
23.4k
        memcpy(p, data, len);
208
23.4k
    }
209
26.1k
    return 1;
210
27.8k
}
Unexecuted instantiation: RIPEMD160_Update
Unexecuted instantiation: ossl_sm3_update
211
212
void HASH_TRANSFORM(HASH_CTX *c, const unsigned char *data)
213
3.40k
{
214
3.40k
    HASH_BLOCK_DATA_ORDER(c, data, 1);
215
3.40k
}
SHA1_Transform
Line
Count
Source
213
2.42k
{
214
2.42k
    HASH_BLOCK_DATA_ORDER(c, data, 1);
215
2.42k
}
SHA256_Transform
Line
Count
Source
213
980
{
214
980
    HASH_BLOCK_DATA_ORDER(c, data, 1);
215
980
}
Unexecuted instantiation: MD4_Transform
Unexecuted instantiation: MD5_Transform
Unexecuted instantiation: RIPEMD160_Transform
Unexecuted instantiation: ossl_sm3_transform
216
217
int HASH_FINAL(unsigned char *md, HASH_CTX *c)
218
100k
{
219
100k
    unsigned char *p = (unsigned char *)c->data;
220
100k
    size_t n = c->num;
221
222
100k
    p[n] = 0x80;                /* there is always room for one */
223
100k
    n++;
224
225
100k
    if (n > (HASH_CBLOCK - 8)) {
226
1.27k
        memset(p + n, 0, HASH_CBLOCK - n);
227
1.27k
        n = 0;
228
1.27k
        HASH_BLOCK_DATA_ORDER(c, p, 1);
229
1.27k
    }
230
100k
    memset(p + n, 0, HASH_CBLOCK - 8 - n);
231
232
100k
    p += HASH_CBLOCK - 8;
233
# if   defined(DATA_ORDER_IS_BIG_ENDIAN)
234
79.9k
    (void)HOST_l2c(c->Nh, p);
235
79.9k
    (void)HOST_l2c(c->Nl, p);
236
# elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
237
20.5k
    (void)HOST_l2c(c->Nl, p);
238
20.5k
    (void)HOST_l2c(c->Nh, p);
239
# endif
240
100k
    p -= HASH_CBLOCK;
241
100k
    HASH_BLOCK_DATA_ORDER(c, p, 1);
242
100k
    c->num = 0;
243
100k
    OPENSSL_cleanse(p, HASH_CBLOCK);
244
245
# ifndef HASH_MAKE_STRING
246
#  error "HASH_MAKE_STRING must be defined!"
247
# else
248
100k
    HASH_MAKE_STRING(c, md);
249
56.1k
# endif
250
251
56.1k
    return 1;
252
100k
}
SHA1_Final
Line
Count
Source
218
23.7k
{
219
23.7k
    unsigned char *p = (unsigned char *)c->data;
220
23.7k
    size_t n = c->num;
221
222
23.7k
    p[n] = 0x80;                /* there is always room for one */
223
23.7k
    n++;
224
225
23.7k
    if (n > (HASH_CBLOCK - 8)) {
226
666
        memset(p + n, 0, HASH_CBLOCK - n);
227
666
        n = 0;
228
666
        HASH_BLOCK_DATA_ORDER(c, p, 1);
229
666
    }
230
23.7k
    memset(p + n, 0, HASH_CBLOCK - 8 - n);
231
232
23.7k
    p += HASH_CBLOCK - 8;
233
23.7k
# if   defined(DATA_ORDER_IS_BIG_ENDIAN)
234
23.7k
    (void)HOST_l2c(c->Nh, p);
235
23.7k
    (void)HOST_l2c(c->Nl, p);
236
# elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
237
    (void)HOST_l2c(c->Nl, p);
238
    (void)HOST_l2c(c->Nh, p);
239
# endif
240
23.7k
    p -= HASH_CBLOCK;
241
23.7k
    HASH_BLOCK_DATA_ORDER(c, p, 1);
242
23.7k
    c->num = 0;
243
23.7k
    OPENSSL_cleanse(p, HASH_CBLOCK);
244
245
# ifndef HASH_MAKE_STRING
246
#  error "HASH_MAKE_STRING must be defined!"
247
# else
248
23.7k
    HASH_MAKE_STRING(c, md);
249
23.7k
# endif
250
251
23.7k
    return 1;
252
23.7k
}
SHA256_Final
Line
Count
Source
218
56.1k
{
219
56.1k
    unsigned char *p = (unsigned char *)c->data;
220
56.1k
    size_t n = c->num;
221
222
56.1k
    p[n] = 0x80;                /* there is always room for one */
223
56.1k
    n++;
224
225
56.1k
    if (n > (HASH_CBLOCK - 8)) {
226
485
        memset(p + n, 0, HASH_CBLOCK - n);
227
485
        n = 0;
228
485
        HASH_BLOCK_DATA_ORDER(c, p, 1);
229
485
    }
230
56.1k
    memset(p + n, 0, HASH_CBLOCK - 8 - n);
231
232
56.1k
    p += HASH_CBLOCK - 8;
233
56.1k
# if   defined(DATA_ORDER_IS_BIG_ENDIAN)
234
56.1k
    (void)HOST_l2c(c->Nh, p);
235
56.1k
    (void)HOST_l2c(c->Nl, p);
236
# elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
237
    (void)HOST_l2c(c->Nl, p);
238
    (void)HOST_l2c(c->Nh, p);
239
# endif
240
56.1k
    p -= HASH_CBLOCK;
241
56.1k
    HASH_BLOCK_DATA_ORDER(c, p, 1);
242
56.1k
    c->num = 0;
243
56.1k
    OPENSSL_cleanse(p, HASH_CBLOCK);
244
245
# ifndef HASH_MAKE_STRING
246
#  error "HASH_MAKE_STRING must be defined!"
247
# else
248
56.1k
    HASH_MAKE_STRING(c, md);
249
56.1k
# endif
250
251
56.1k
    return 1;
252
56.1k
}
Unexecuted instantiation: MD4_Final
MD5_Final
Line
Count
Source
218
20.5k
{
219
20.5k
    unsigned char *p = (unsigned char *)c->data;
220
20.5k
    size_t n = c->num;
221
222
20.5k
    p[n] = 0x80;                /* there is always room for one */
223
20.5k
    n++;
224
225
20.5k
    if (n > (HASH_CBLOCK - 8)) {
226
127
        memset(p + n, 0, HASH_CBLOCK - n);
227
127
        n = 0;
228
127
        HASH_BLOCK_DATA_ORDER(c, p, 1);
229
127
    }
230
20.5k
    memset(p + n, 0, HASH_CBLOCK - 8 - n);
231
232
20.5k
    p += HASH_CBLOCK - 8;
233
# if   defined(DATA_ORDER_IS_BIG_ENDIAN)
234
    (void)HOST_l2c(c->Nh, p);
235
    (void)HOST_l2c(c->Nl, p);
236
# elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
237
20.5k
    (void)HOST_l2c(c->Nl, p);
238
20.5k
    (void)HOST_l2c(c->Nh, p);
239
20.5k
# endif
240
20.5k
    p -= HASH_CBLOCK;
241
20.5k
    HASH_BLOCK_DATA_ORDER(c, p, 1);
242
20.5k
    c->num = 0;
243
20.5k
    OPENSSL_cleanse(p, HASH_CBLOCK);
244
245
# ifndef HASH_MAKE_STRING
246
#  error "HASH_MAKE_STRING must be defined!"
247
# else
248
20.5k
    HASH_MAKE_STRING(c, md);
249
20.5k
# endif
250
251
20.5k
    return 1;
252
20.5k
}
Unexecuted instantiation: RIPEMD160_Final
Unexecuted instantiation: ossl_sm3_final
253
254
# ifndef MD32_REG_T
255
#  if defined(__alpha) || defined(__sparcv9) || defined(__mips)
256
#   define MD32_REG_T long
257
/*
258
 * This comment was originally written for MD5, which is why it
259
 * discusses A-D. But it basically applies to all 32-bit digests,
260
 * which is why it was moved to common header file.
261
 *
262
 * In case you wonder why A-D are declared as long and not
263
 * as MD5_LONG. Doing so results in slight performance
264
 * boost on LP64 architectures. The catch is we don't
265
 * really care if 32 MSBs of a 64-bit register get polluted
266
 * with eventual overflows as we *save* only 32 LSBs in
267
 * *either* case. Now declaring 'em long excuses the compiler
268
 * from keeping 32 MSBs zeroed resulting in 13% performance
269
 * improvement under SPARC Solaris7/64 and 5% under AlphaLinux.
270
 * Well, to be honest it should say that this *prevents*
271
 * performance degradation.
272
 */
273
#  else
274
/*
275
 * Above is not absolute and there are LP64 compilers that
276
 * generate better code if MD32_REG_T is defined int. The above
277
 * pre-processor condition reflects the circumstances under which
278
 * the conclusion was made and is subject to further extension.
279
 */
280
#   define MD32_REG_T int
281
#  endif
282
# endif
283
284
#endif