Import OpenSSL-0.9.8i.
[dragonfly.git] / crypto / openssl-0.9.7e / fips / sha1 / fips_md32_common.h
blob55d65f5821c314125596e8c0965a4429a92172f4
1 /* crypto/md32_common.h */
2 /* ====================================================================
3 * Copyright (c) 1999-2002 The OpenSSL Project. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
15 * distribution.
17 * 3. All advertising materials mentioning features or use of this
18 * software must display the following acknowledgment:
19 * "This product includes software developed by the OpenSSL Project
20 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23 * endorse or promote products derived from this software without
24 * prior written permission. For written permission, please contact
25 * licensing@OpenSSL.org.
27 * 5. Products derived from this software may not be called "OpenSSL"
28 * nor may "OpenSSL" appear in their names without prior written
29 * permission of the OpenSSL Project.
31 * 6. Redistributions of any form whatsoever must retain the following
32 * acknowledgment:
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47 * OF THE POSSIBILITY OF SUCH DAMAGE.
48 * ====================================================================
50 * This product includes cryptographic software written by Eric Young
51 * (eay@cryptsoft.com). This product includes software written by Tim
52 * Hudson (tjh@cryptsoft.com).
57 * This is a generic 32 bit "collector" for message digest algorithms.
58 * Whenever needed it collects input character stream into chunks of
59 * 32 bit values and invokes a block function that performs actual hash
60 * calculations.
62 * Porting guide.
64 * Obligatory macros:
66 * DATA_ORDER_IS_BIG_ENDIAN or DATA_ORDER_IS_LITTLE_ENDIAN
67 * this macro defines byte order of input stream.
68 * HASH_CBLOCK
69 * size of a unit chunk HASH_BLOCK operates on.
70 * HASH_LONG
71 * has to be at lest 32 bit wide, if it's wider, then
72 * HASH_LONG_LOG2 *has to* be defined along
73 * HASH_CTX
74 * context structure that at least contains following
75 * members:
76 * typedef struct {
77 * ...
78 * HASH_LONG Nl,Nh;
79 * HASH_LONG data[HASH_LBLOCK];
80 * int num;
81 * ...
82 * } HASH_CTX;
83 * HASH_UPDATE
84 * name of "Update" function, implemented here.
85 * HASH_TRANSFORM
86 * name of "Transform" function, implemented here.
87 * HASH_FINAL
88 * name of "Final" function, implemented here.
89 * HASH_BLOCK_HOST_ORDER
90 * name of "block" function treating *aligned* input message
91 * in host byte order, implemented externally.
92 * HASH_BLOCK_DATA_ORDER
93 * name of "block" function treating *unaligned* input message
94 * in original (data) byte order, implemented externally (it
95 * actually is optional if data and host are of the same
96 * "endianess").
97 * HASH_MAKE_STRING
98 * macro convering context variables to an ASCII hash string.
100 * Optional macros:
102 * B_ENDIAN or L_ENDIAN
103 * defines host byte-order.
104 * HASH_LONG_LOG2
105 * defaults to 2 if not states otherwise.
106 * HASH_LBLOCK
107 * assumed to be HASH_CBLOCK/4 if not stated otherwise.
108 * HASH_BLOCK_DATA_ORDER_ALIGNED
109 * alternative "block" function capable of treating
110 * aligned input message in original (data) order,
111 * implemented externally.
113 * MD5 example:
115 * #define DATA_ORDER_IS_LITTLE_ENDIAN
117 * #define HASH_LONG MD5_LONG
118 * #define HASH_LONG_LOG2 MD5_LONG_LOG2
119 * #define HASH_CTX MD5_CTX
120 * #define HASH_CBLOCK MD5_CBLOCK
121 * #define HASH_LBLOCK MD5_LBLOCK
122 * #define HASH_UPDATE MD5_Update
123 * #define HASH_TRANSFORM MD5_Transform
124 * #define HASH_FINAL MD5_Final
125 * #define HASH_BLOCK_HOST_ORDER md5_block_host_order
126 * #define HASH_BLOCK_DATA_ORDER md5_block_data_order
128 * <appro@fy.chalmers.se>
131 #if !defined(DATA_ORDER_IS_BIG_ENDIAN) && !defined(DATA_ORDER_IS_LITTLE_ENDIAN)
132 #error "DATA_ORDER must be defined!"
133 #endif
135 #ifndef HASH_CBLOCK
136 #error "HASH_CBLOCK must be defined!"
137 #endif
138 #ifndef HASH_LONG
139 #error "HASH_LONG must be defined!"
140 #endif
141 #ifndef HASH_CTX
142 #error "HASH_CTX must be defined!"
143 #endif
145 #ifndef HASH_UPDATE
146 #error "HASH_UPDATE must be defined!"
147 #endif
148 #ifndef HASH_TRANSFORM
149 #error "HASH_TRANSFORM must be defined!"
150 #endif
151 #ifndef HASH_FINAL
152 #error "HASH_FINAL must be defined!"
153 #endif
155 #ifndef HASH_BLOCK_HOST_ORDER
156 #error "HASH_BLOCK_HOST_ORDER must be defined!"
157 #endif
159 #if 0
161 * Moved below as it's required only if HASH_BLOCK_DATA_ORDER_ALIGNED
162 * isn't defined.
164 #ifndef HASH_BLOCK_DATA_ORDER
165 #error "HASH_BLOCK_DATA_ORDER must be defined!"
166 #endif
167 #endif
169 #ifndef HASH_LBLOCK
170 #define HASH_LBLOCK (HASH_CBLOCK/4)
171 #endif
173 #ifndef HASH_LONG_LOG2
174 #define HASH_LONG_LOG2 2
175 #endif
178 * Engage compiler specific rotate intrinsic function if available.
180 #undef ROTATE
181 #ifndef PEDANTIC
182 # if defined(_MSC_VER) || defined(__ICC)
183 # define ROTATE(a,n) _lrotl(a,n)
184 # elif defined(__MWERKS__)
185 # if defined(__POWERPC__)
186 # define ROTATE(a,n) __rlwinm(a,n,0,31)
187 # elif defined(__MC68K__)
188 /* Motorola specific tweak. <appro@fy.chalmers.se> */
189 # define ROTATE(a,n) ( n<24 ? __rol(a,n) : __ror(a,32-n) )
190 # else
191 # define ROTATE(a,n) __rol(a,n)
192 # endif
193 # elif defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM)
195 * Some GNU C inline assembler templates. Note that these are
196 * rotates by *constant* number of bits! But that's exactly
197 * what we need here...
199 * <appro@fy.chalmers.se>
201 # if defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__)
202 # define ROTATE(a,n) ({ register unsigned int ret; \
203 asm ( \
204 "roll %1,%0" \
205 : "=r"(ret) \
206 : "I"(n), "0"(a) \
207 : "cc"); \
208 ret; \
210 # elif defined(__powerpc) || defined(__ppc)
211 # define ROTATE(a,n) ({ register unsigned int ret; \
212 asm ( \
213 "rlwinm %0,%1,%2,0,31" \
214 : "=r"(ret) \
215 : "r"(a), "I"(n)); \
216 ret; \
218 # endif
219 # endif
222 * Engage compiler specific "fetch in reverse byte order"
223 * intrinsic function if available.
225 # if defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM)
226 /* some GNU C inline assembler templates by <appro@fy.chalmers.se> */
227 # if (defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__)) && !defined(I386_ONLY)
228 # define BE_FETCH32(a) ({ register unsigned int l=(a);\
229 asm ( \
230 "bswapl %0" \
231 : "=r"(l) : "0"(l)); \
232 l; \
234 # elif defined(__powerpc)
235 # define LE_FETCH32(a) ({ register unsigned int l; \
236 asm ( \
237 "lwbrx %0,0,%1" \
238 : "=r"(l) \
239 : "r"(a)); \
240 l; \
243 # elif defined(__sparc) && defined(OPENSSL_SYS_ULTRASPARC)
244 # define LE_FETCH32(a) ({ register unsigned int l; \
245 asm ( \
246 "lda [%1]#ASI_PRIMARY_LITTLE,%0"\
247 : "=r"(l) \
248 : "r"(a)); \
249 l; \
251 # endif
252 # endif
253 #endif /* PEDANTIC */
255 #if HASH_LONG_LOG2==2 /* Engage only if sizeof(HASH_LONG)== 4 */
256 /* A nice byte order reversal from Wei Dai <weidai@eskimo.com> */
257 #ifdef ROTATE
258 /* 5 instructions with rotate instruction, else 9 */
259 #define REVERSE_FETCH32(a,l) ( \
260 l=*(const HASH_LONG *)(a), \
261 ((ROTATE(l,8)&0x00FF00FF)|(ROTATE((l&0x00FF00FF),24))) \
263 #else
264 /* 6 instructions with rotate instruction, else 8 */
265 #define REVERSE_FETCH32(a,l) ( \
266 l=*(const HASH_LONG *)(a), \
267 l=(((l>>8)&0x00FF00FF)|((l&0x00FF00FF)<<8)), \
268 ROTATE(l,16) \
271 * Originally the middle line started with l=(((l&0xFF00FF00)>>8)|...
272 * It's rewritten as above for two reasons:
273 * - RISCs aren't good at long constants and have to explicitely
274 * compose 'em with several (well, usually 2) instructions in a
275 * register before performing the actual operation and (as you
276 * already realized:-) having same constant should inspire the
277 * compiler to permanently allocate the only register for it;
278 * - most modern CPUs have two ALUs, but usually only one has
279 * circuitry for shifts:-( this minor tweak inspires compiler
280 * to schedule shift instructions in a better way...
282 * <appro@fy.chalmers.se>
284 #endif
285 #endif
287 #ifndef ROTATE
288 #define ROTATE(a,n) (((a)<<(n))|(((a)&0xffffffff)>>(32-(n))))
289 #endif
292 * Make some obvious choices. E.g., HASH_BLOCK_DATA_ORDER_ALIGNED
293 * and HASH_BLOCK_HOST_ORDER ought to be the same if input data
294 * and host are of the same "endianess". It's possible to mask
295 * this with blank #define HASH_BLOCK_DATA_ORDER though...
297 * <appro@fy.chalmers.se>
299 #if defined(B_ENDIAN)
300 # if defined(DATA_ORDER_IS_BIG_ENDIAN)
301 # if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2
302 # define HASH_BLOCK_DATA_ORDER_ALIGNED HASH_BLOCK_HOST_ORDER
303 # endif
304 # elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
305 # ifndef HOST_FETCH32
306 # ifdef LE_FETCH32
307 # define HOST_FETCH32(p,l) LE_FETCH32(p)
308 # elif defined(REVERSE_FETCH32)
309 # define HOST_FETCH32(p,l) REVERSE_FETCH32(p,l)
310 # endif
311 # endif
312 # endif
313 #elif defined(L_ENDIAN)
314 # if defined(DATA_ORDER_IS_LITTLE_ENDIAN)
315 # if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2
316 # define HASH_BLOCK_DATA_ORDER_ALIGNED HASH_BLOCK_HOST_ORDER
317 # endif
318 # elif defined(DATA_ORDER_IS_BIG_ENDIAN)
319 # ifndef HOST_FETCH32
320 # ifdef BE_FETCH32
321 # define HOST_FETCH32(p,l) BE_FETCH32(p)
322 # elif defined(REVERSE_FETCH32)
323 # define HOST_FETCH32(p,l) REVERSE_FETCH32(p,l)
324 # endif
325 # endif
326 # endif
327 #endif
329 #if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED)
330 #ifndef HASH_BLOCK_DATA_ORDER
331 #error "HASH_BLOCK_DATA_ORDER must be defined!"
332 #endif
333 #endif
335 #if defined(DATA_ORDER_IS_BIG_ENDIAN)
337 #define HOST_c2l(c,l) (l =(((unsigned long)(*((c)++)))<<24), \
338 l|=(((unsigned long)(*((c)++)))<<16), \
339 l|=(((unsigned long)(*((c)++)))<< 8), \
340 l|=(((unsigned long)(*((c)++))) ), \
342 #define HOST_p_c2l(c,l,n) { \
343 switch (n) { \
344 case 0: l =((unsigned long)(*((c)++)))<<24; \
345 case 1: l|=((unsigned long)(*((c)++)))<<16; \
346 case 2: l|=((unsigned long)(*((c)++)))<< 8; \
347 case 3: l|=((unsigned long)(*((c)++))); \
349 #define HOST_p_c2l_p(c,l,sc,len) { \
350 switch (sc) { \
351 case 0: l =((unsigned long)(*((c)++)))<<24; \
352 if (--len == 0) break; \
353 case 1: l|=((unsigned long)(*((c)++)))<<16; \
354 if (--len == 0) break; \
355 case 2: l|=((unsigned long)(*((c)++)))<< 8; \
357 /* NOTE the pointer is not incremented at the end of this */
358 #define HOST_c2l_p(c,l,n) { \
359 l=0; (c)+=n; \
360 switch (n) { \
361 case 3: l =((unsigned long)(*(--(c))))<< 8; \
362 case 2: l|=((unsigned long)(*(--(c))))<<16; \
363 case 1: l|=((unsigned long)(*(--(c))))<<24; \
365 #define HOST_l2c(l,c) (*((c)++)=(unsigned char)(((l)>>24)&0xff), \
366 *((c)++)=(unsigned char)(((l)>>16)&0xff), \
367 *((c)++)=(unsigned char)(((l)>> 8)&0xff), \
368 *((c)++)=(unsigned char)(((l) )&0xff), \
371 #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
373 #define HOST_c2l(c,l) (l =(((unsigned long)(*((c)++))) ), \
374 l|=(((unsigned long)(*((c)++)))<< 8), \
375 l|=(((unsigned long)(*((c)++)))<<16), \
376 l|=(((unsigned long)(*((c)++)))<<24), \
378 #define HOST_p_c2l(c,l,n) { \
379 switch (n) { \
380 case 0: l =((unsigned long)(*((c)++))); \
381 case 1: l|=((unsigned long)(*((c)++)))<< 8; \
382 case 2: l|=((unsigned long)(*((c)++)))<<16; \
383 case 3: l|=((unsigned long)(*((c)++)))<<24; \
385 #define HOST_p_c2l_p(c,l,sc,len) { \
386 switch (sc) { \
387 case 0: l =((unsigned long)(*((c)++))); \
388 if (--len == 0) break; \
389 case 1: l|=((unsigned long)(*((c)++)))<< 8; \
390 if (--len == 0) break; \
391 case 2: l|=((unsigned long)(*((c)++)))<<16; \
393 /* NOTE the pointer is not incremented at the end of this */
394 #define HOST_c2l_p(c,l,n) { \
395 l=0; (c)+=n; \
396 switch (n) { \
397 case 3: l =((unsigned long)(*(--(c))))<<16; \
398 case 2: l|=((unsigned long)(*(--(c))))<< 8; \
399 case 1: l|=((unsigned long)(*(--(c)))); \
401 #define HOST_l2c(l,c) (*((c)++)=(unsigned char)(((l) )&0xff), \
402 *((c)++)=(unsigned char)(((l)>> 8)&0xff), \
403 *((c)++)=(unsigned char)(((l)>>16)&0xff), \
404 *((c)++)=(unsigned char)(((l)>>24)&0xff), \
407 #endif
410 * Time for some action:-)
413 int HASH_UPDATE (HASH_CTX *c, const void *data_, FIPS_SHA_SIZE_T len)
415 const unsigned char *data=data_;
416 register HASH_LONG * p;
417 register HASH_LONG l;
418 int sw,sc,ew,ec;
420 if(FIPS_selftest_failed())
421 return 0;
423 if (len==0) return 1;
425 l=(c->Nl+(((HASH_LONG)len)<<3))&0xffffffffUL;
426 /* 95-05-24 eay Fixed a bug with the overflow handling, thanks to
427 * Wei Dai <weidai@eskimo.com> for pointing it out. */
428 if (l < c->Nl) /* overflow */
429 c->Nh++;
430 c->Nh+=(len>>29);
431 c->Nl=l;
433 if (c->num != 0)
435 p=c->data;
436 sw=c->num>>2;
437 sc=c->num&0x03;
439 if ((c->num+len) >= HASH_CBLOCK)
441 l=p[sw]; HOST_p_c2l(data,l,sc); p[sw++]=l;
442 for (; sw<HASH_LBLOCK; sw++)
444 HOST_c2l(data,l); p[sw]=l;
446 HASH_BLOCK_HOST_ORDER (c,p,1);
447 len-=(HASH_CBLOCK-c->num);
448 c->num=0;
449 /* drop through and do the rest */
451 else
453 c->num+=len;
454 if ((sc+len) < 4) /* ugly, add char's to a word */
456 l=p[sw]; HOST_p_c2l_p(data,l,sc,len); p[sw]=l;
458 else
460 ew=(c->num>>2);
461 ec=(c->num&0x03);
462 if (sc)
463 l=p[sw];
464 HOST_p_c2l(data,l,sc);
465 p[sw++]=l;
466 for (; sw < ew; sw++)
468 HOST_c2l(data,l); p[sw]=l;
470 if (ec)
472 HOST_c2l_p(data,l,ec); p[sw]=l;
475 return 1;
479 sw=len/HASH_CBLOCK;
480 if (sw > 0)
482 #if defined(HASH_BLOCK_DATA_ORDER_ALIGNED)
484 * Note that HASH_BLOCK_DATA_ORDER_ALIGNED gets defined
485 * only if sizeof(HASH_LONG)==4.
487 if ((((unsigned long)data)%4) == 0)
489 /* data is properly aligned so that we can cast it: */
490 HASH_BLOCK_DATA_ORDER_ALIGNED (c,(const HASH_LONG *)data,sw);
491 sw*=HASH_CBLOCK;
492 data+=sw;
493 len-=sw;
495 else
496 #if !defined(HASH_BLOCK_DATA_ORDER)
497 while (sw--)
499 memcpy (p=c->data,data,HASH_CBLOCK);
500 HASH_BLOCK_DATA_ORDER_ALIGNED(c,p,1);
501 data+=HASH_CBLOCK;
502 len-=HASH_CBLOCK;
504 #endif
505 #endif
506 #if defined(HASH_BLOCK_DATA_ORDER)
508 HASH_BLOCK_DATA_ORDER(c,data,sw);
509 sw*=HASH_CBLOCK;
510 data+=sw;
511 len-=sw;
513 #endif
516 if (len!=0)
518 p = c->data;
519 c->num = len;
520 ew=len>>2; /* words to copy */
521 ec=len&0x03;
522 for (; ew; ew--,p++)
524 HOST_c2l(data,l); *p=l;
526 HOST_c2l_p(data,l,ec);
527 *p=l;
529 return 1;
533 void HASH_TRANSFORM (HASH_CTX *c, const unsigned char *data)
535 #if defined(HASH_BLOCK_DATA_ORDER_ALIGNED)
536 if ((((unsigned long)data)%4) == 0)
537 /* data is properly aligned so that we can cast it: */
538 HASH_BLOCK_DATA_ORDER_ALIGNED (c,(const HASH_LONG *)data,1);
539 else
540 #if !defined(HASH_BLOCK_DATA_ORDER)
542 memcpy (c->data,data,HASH_CBLOCK);
543 HASH_BLOCK_DATA_ORDER_ALIGNED (c,c->data,1);
545 #endif
546 #endif
547 #if defined(HASH_BLOCK_DATA_ORDER)
548 HASH_BLOCK_DATA_ORDER (c,data,1);
549 #endif
553 int HASH_FINAL (unsigned char *md, HASH_CTX *c)
555 register HASH_LONG *p;
556 register unsigned long l;
557 register int i,j;
558 static const unsigned char end[4]={0x80,0x00,0x00,0x00};
559 const unsigned char *cp=end;
561 /* c->num should definitly have room for at least one more byte. */
562 p=c->data;
563 i=c->num>>2;
564 j=c->num&0x03;
566 #if 0
567 /* purify often complains about the following line as an
568 * Uninitialized Memory Read. While this can be true, the
569 * following p_c2l macro will reset l when that case is true.
570 * This is because j&0x03 contains the number of 'valid' bytes
571 * already in p[i]. If and only if j&0x03 == 0, the UMR will
572 * occur but this is also the only time p_c2l will do
573 * l= *(cp++) instead of l|= *(cp++)
574 * Many thanks to Alex Tang <altitude@cic.net> for pickup this
575 * 'potential bug' */
576 #ifdef PURIFY
577 if (j==0) p[i]=0; /* Yeah, but that's not the way to fix it:-) */
578 #endif
579 l=p[i];
580 #else
581 l = (j==0) ? 0 : p[i];
582 #endif
583 HOST_p_c2l(cp,l,j); p[i++]=l; /* i is the next 'undefined word' */
585 if (i>(HASH_LBLOCK-2)) /* save room for Nl and Nh */
587 if (i<HASH_LBLOCK) p[i]=0;
588 HASH_BLOCK_HOST_ORDER (c,p,1);
589 i=0;
591 for (; i<(HASH_LBLOCK-2); i++)
592 p[i]=0;
594 #if defined(DATA_ORDER_IS_BIG_ENDIAN)
595 p[HASH_LBLOCK-2]=c->Nh;
596 p[HASH_LBLOCK-1]=c->Nl;
597 #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
598 p[HASH_LBLOCK-2]=c->Nl;
599 p[HASH_LBLOCK-1]=c->Nh;
600 #endif
601 HASH_BLOCK_HOST_ORDER (c,p,1);
603 #ifndef HASH_MAKE_STRING
604 #error "HASH_MAKE_STRING must be defined!"
605 #else
606 HASH_MAKE_STRING(c,md);
607 #endif
609 c->num=0;
610 /* clear stuff, HASH_BLOCK may be leaving some stuff on the stack
611 * but I'm not worried :-)
612 OPENSSL_cleanse((void *)c,sizeof(HASH_CTX));
614 return 1;
617 #ifndef MD32_REG_T
618 #define MD32_REG_T long
620 * This comment was originaly written for MD5, which is why it
621 * discusses A-D. But it basically applies to all 32-bit digests,
622 * which is why it was moved to common header file.
624 * In case you wonder why A-D are declared as long and not
625 * as MD5_LONG. Doing so results in slight performance
626 * boost on LP64 architectures. The catch is we don't
627 * really care if 32 MSBs of a 64-bit register get polluted
628 * with eventual overflows as we *save* only 32 LSBs in
629 * *either* case. Now declaring 'em long excuses the compiler
630 * from keeping 32 MSBs zeroed resulting in 13% performance
631 * improvement under SPARC Solaris7/64 and 5% under AlphaLinux.
632 * Well, to be honest it should say that this *prevents*
633 * performance degradation.
634 * <appro@fy.chalmers.se>
635 * Apparently there're LP64 compilers that generate better
636 * code if A-D are declared int. Most notably GCC-x86_64
637 * generates better code.
638 * <appro@fy.chalmers.se>
640 #endif