/* crypto/md32_common.h */

/* ====================================================================

 * Copyright (c) 1999-2002 The OpenSSL Project.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer. 

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    licensing@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

 * OF THE POSSIBILITY OF SUCH DAMAGE.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

/*

 * This is a generic 32 bit "collector" for message digest algorithms.

 * Whenever needed it collects input character stream into chunks of

 * 32 bit values and invokes a block function that performs actual hash

 * calculations.

 *

 * Porting guide.

 *

 * Obligatory macros:

 *

 * DATA_ORDER_IS_BIG_ENDIAN or DATA_ORDER_IS_LITTLE_ENDIAN

 *	this macro defines byte order of input stream.

 * HASH_CBLOCK

 *	size of a unit chunk HASH_BLOCK operates on.

 * HASH_LONG

 *	has to be at lest 32 bit wide, if it's wider, then

 *	HASH_LONG_LOG2 *has to* be defined along

 * HASH_CTX

 *	context structure that at least contains following

 *	members:

 *		typedef struct {

 *			...

 *			HASH_LONG	Nl,Nh;

 *			HASH_LONG	data[HASH_LBLOCK];

 *			unsigned int	num;

 *			...

 *			} HASH_CTX;

 * HASH_UPDATE

 *	name of "Update" function, implemented here.

 * HASH_TRANSFORM

 *	name of "Transform" function, implemented here.

 * HASH_FINAL

 *	name of "Final" function, implemented here.

 * HASH_BLOCK_HOST_ORDER

 *	name of "block" function treating *aligned* input message

 *	in host byte order, implemented externally.

 * HASH_BLOCK_DATA_ORDER

 *	name of "block" function treating *unaligned* input message

 *	in original (data) byte order, implemented externally (it

 *	actually is optional if data and host are of the same

 *	"endianess").

 * HASH_MAKE_STRING

 *	macro convering context variables to an ASCII hash string.

 *

 * Optional macros:

 *

 * B_ENDIAN or L_ENDIAN

 *	defines host byte-order.

 * HASH_LONG_LOG2

 *	defaults to 2 if not states otherwise.

 * HASH_LBLOCK

 *	assumed to be HASH_CBLOCK/4 if not stated otherwise.

 * HASH_BLOCK_DATA_ORDER_ALIGNED

 *	alternative "block" function capable of treating

 *	aligned input message in original (data) order,

 *	implemented externally.

 *

 * MD5 example:

 *

 *	#define DATA_ORDER_IS_LITTLE_ENDIAN

 *

 *	#define HASH_LONG		MD5_LONG

 *	#define HASH_LONG_LOG2		MD5_LONG_LOG2

 *	#define HASH_CTX		MD5_CTX

 *	#define HASH_CBLOCK		MD5_CBLOCK

 *	#define HASH_LBLOCK		MD5_LBLOCK

 *	#define HASH_UPDATE		MD5_Update

 *	#define HASH_TRANSFORM		MD5_Transform

 *	#define HASH_FINAL		MD5_Final

 *	#define HASH_BLOCK_HOST_ORDER	md5_block_host_order

 *	#define HASH_BLOCK_DATA_ORDER	md5_block_data_order

 *

 *					<appro@fy.chalmers.se>

 */

#if !defined(DATA_ORDER_IS_BIG_ENDIAN) && !defined(DATA_ORDER_IS_LITTLE_ENDIAN)

#error "DATA_ORDER must be defined!"

#endif

#ifndef HASH_CBLOCK

#error "HASH_CBLOCK must be defined!"

#endif

#ifndef HASH_LONG

#error "HASH_LONG must be defined!"

#endif

#ifndef HASH_CTX

#error "HASH_CTX must be defined!"

#endif

#ifndef HASH_UPDATE

#error "HASH_UPDATE must be defined!"

#endif

#ifndef HASH_TRANSFORM

#error "HASH_TRANSFORM must be defined!"

#endif

#ifndef HASH_FINAL

#error "HASH_FINAL must be defined!"

#endif

#ifndef HASH_BLOCK_HOST_ORDER

#error "HASH_BLOCK_HOST_ORDER must be defined!"

#endif

#if 0

/*

 * Moved below as it's required only if HASH_BLOCK_DATA_ORDER_ALIGNED

 * isn't defined.

 */

#ifndef HASH_BLOCK_DATA_ORDER

#error "HASH_BLOCK_DATA_ORDER must be defined!"

#endif

#endif

#ifndef HASH_LBLOCK

#define HASH_LBLOCK	(HASH_CBLOCK/4)

#endif

#ifndef HASH_LONG_LOG2

#define HASH_LONG_LOG2	2

#endif

/*

 * Engage compiler specific rotate intrinsic function if available.

 */

#undef ROTATE

#ifndef PEDANTIC

# if defined(_MSC_VER) || defined(__ICC)

#  define ROTATE(a,n)	_lrotl(a,n)

# elif defined(__MWERKS__)

#  if defined(__POWERPC__)

#   define ROTATE(a,n)	__rlwinm(a,n,0,31)

#  elif defined(__MC68K__)

    /* Motorola specific tweak. <appro@fy.chalmers.se> */

#   define ROTATE(a,n)	( n<24 ? __rol(a,n) : __ror(a,32-n) )

#  else

#   define ROTATE(a,n)	__rol(a,n)

#  endif

# elif defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM)

  /*

   * Some GNU C inline assembler templates. Note that these are

   * rotates by *constant* number of bits! But that's exactly

   * what we need here...

   * 					<appro@fy.chalmers.se>

   */

#  if defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__)

#   define ROTATE(a,n)	({ register unsigned int ret;	\

				asm (			\

				"roll %1,%0"		\

				: "=r"(ret)		\

				: "I"(n), "0"(a)	\

				: "cc");		\

			   ret;				\

			})

#  elif defined(__powerpc) || defined(__ppc__) || defined(__powerpc64__)

#   define ROTATE(a,n)	({ register unsigned int ret;	\

				asm (			\

				"rlwinm %0,%1,%2,0,31"	\

				: "=r"(ret)		\

				: "r"(a), "I"(n));	\

			   ret;				\

			})

#  endif

# endif

#endif /* PEDANTIC */

#if HASH_LONG_LOG2==2	/* Engage only if sizeof(HASH_LONG)== 4 */

/* A nice byte order reversal from Wei Dai <weidai@eskimo.com> */

#ifdef ROTATE

/* 5 instructions with rotate instruction, else 9 */

#define REVERSE_FETCH32(a,l)	(					\

		l=*(const HASH_LONG *)(a),				\

		((ROTATE(l,8)&0x00FF00FF)|(ROTATE((l&0x00FF00FF),24)))	\

				)

#else

/* 6 instructions with rotate instruction, else 8 */

#define REVERSE_FETCH32(a,l)	(				\

		l=*(const HASH_LONG *)(a),			\

		l=(((l>>8)&0x00FF00FF)|((l&0x00FF00FF)<<8)),	\

		ROTATE(l,16)					\

				)

/*

 * Originally the middle line started with l=(((l&0xFF00FF00)>>8)|...

 * It's rewritten as above for two reasons:

 *	- RISCs aren't good at long constants and have to explicitely

 *	  compose 'em with several (well, usually 2) instructions in a

 *	  register before performing the actual operation and (as you

 *	  already realized:-) having same constant should inspire the

 *	  compiler to permanently allocate the only register for it;

 *	- most modern CPUs have two ALUs, but usually only one has

 *	  circuitry for shifts:-( this minor tweak inspires compiler

 *	  to schedule shift instructions in a better way...

 *

 *				<appro@fy.chalmers.se>

 */

#endif

#endif

#ifndef ROTATE

#define ROTATE(a,n)     (((a)<<(n))|(((a)&0xffffffff)>>(32-(n))))

#endif

/*

 * Make some obvious choices. E.g., HASH_BLOCK_DATA_ORDER_ALIGNED

 * and HASH_BLOCK_HOST_ORDER ought to be the same if input data

 * and host are of the same "endianess". It's possible to mask

 * this with blank #define HASH_BLOCK_DATA_ORDER though...

 *

 *				<appro@fy.chalmers.se>

 */

#if defined(B_ENDIAN)

#  if defined(DATA_ORDER_IS_BIG_ENDIAN)

#    if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2

#      define HASH_BLOCK_DATA_ORDER_ALIGNED	HASH_BLOCK_HOST_ORDER

#    endif

#  endif

#elif defined(L_ENDIAN)

#  if defined(DATA_ORDER_IS_LITTLE_ENDIAN)

#    if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2

#      define HASH_BLOCK_DATA_ORDER_ALIGNED	HASH_BLOCK_HOST_ORDER

#    endif

#  endif

#endif

#if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED)

#ifndef HASH_BLOCK_DATA_ORDER

#error "HASH_BLOCK_DATA_ORDER must be defined!"

#endif

#endif

#if defined(DATA_ORDER_IS_BIG_ENDIAN)

#ifndef PEDANTIC

# if defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM)

#  if ((defined(__i386) || defined(__i386__)) && !defined(I386_ONLY)) || \

      (defined(__x86_64) || defined(__x86_64__))

    /*

     * This gives ~30-40% performance improvement in SHA-256 compiled

     * with gcc [on P4]. Well, first macro to be frank. We can pull

     * this trick on x86* platforms only, because these CPUs can fetch

     * unaligned data without raising an exception.

     */

#   define HOST_c2l(c,l)	({ unsigned int r=*((const unsigned int *)(c));	\

				   asm ("bswapl %0":"=r"(r):"0"(r));	\

				   (c)+=4; (l)=r;			})

#   define HOST_l2c(l,c)	({ unsigned int r=(l);			\

				   asm ("bswapl %0":"=r"(r):"0"(r));	\

				   *((unsigned int *)(c))=r; (c)+=4; r;	})

#  endif

# endif

#endif

#ifndef HOST_c2l

#define HOST_c2l(c,l)	(l =(((unsigned long)(*((c)++)))<<24),		\

			 l|=(((unsigned long)(*((c)++)))<<16),		\

			 l|=(((unsigned long)(*((c)++)))<< 8),		\

			 l|=(((unsigned long)(*((c)++)))    ),		\

			 l)

#endif

#define HOST_p_c2l(c,l,n)	{					\

			switch (n) {					\

			case 0: l =((unsigned long)(*((c)++)))<<24;	\

			case 1: l|=((unsigned long)(*((c)++)))<<16;	\

			case 2: l|=((unsigned long)(*((c)++)))<< 8;	\

			case 3: l|=((unsigned long)(*((c)++)));		\

				} }

#define HOST_p_c2l_p(c,l,sc,len) {					\

			switch (sc) {					\

			case 0: l =((unsigned long)(*((c)++)))<<24;	\

				if (--len == 0) break;			\

			case 1: l|=((unsigned long)(*((c)++)))<<16;	\

				if (--len == 0) break;			\

			case 2: l|=((unsigned long)(*((c)++)))<< 8;	\

				} }

/* NOTE the pointer is not incremented at the end of this */

#define HOST_c2l_p(c,l,n)	{					\

			l=0; (c)+=n;					\

			switch (n) {					\

			case 3: l =((unsigned long)(*(--(c))))<< 8;	\

			case 2: l|=((unsigned long)(*(--(c))))<<16;	\

			case 1: l|=((unsigned long)(*(--(c))))<<24;	\

				} }

#ifndef HOST_l2c

#define HOST_l2c(l,c)	(*((c)++)=(unsigned char)(((l)>>24)&0xff),	\

			 *((c)++)=(unsigned char)(((l)>>16)&0xff),	\

			 *((c)++)=(unsigned char)(((l)>> 8)&0xff),	\

			 *((c)++)=(unsigned char)(((l)    )&0xff),	\

			 l)

#endif

#elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)

#if defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__)

# ifndef B_ENDIAN

   /* See comment in DATA_ORDER_IS_BIG_ENDIAN section. */

#  define HOST_c2l(c,l)	((l)=*((const unsigned int *)(c)), (c)+=4, l)

#  define HOST_l2c(l,c)	(*((unsigned int *)(c))=(l), (c)+=4, l)

# endif

#endif

#ifndef HOST_c2l

#define HOST_c2l(c,l)	(l =(((unsigned long)(*((c)++)))    ),		\

			 l|=(((unsigned long)(*((c)++)))<< 8),		\

			 l|=(((unsigned long)(*((c)++)))<<16),		\

			 l|=(((unsigned long)(*((c)++)))<<24),		\

			 l)

#endif

#define HOST_p_c2l(c,l,n)	{					\

			switch (n) {					\

			case 0: l =((unsigned long)(*((c)++)));		\

			case 1: l|=((unsigned long)(*((c)++)))<< 8;	\

			case 2: l|=((unsigned long)(*((c)++)))<<16;	\

			case 3: l|=((unsigned long)(*((c)++)))<<24;	\

				} }

#define HOST_p_c2l_p(c,l,sc,len) {					\

			switch (sc) {					\

			case 0: l =((unsigned long)(*((c)++)));		\

				if (--len == 0) break;			\

			case 1: l|=((unsigned long)(*((c)++)))<< 8;	\

				if (--len == 0) break;			\

			case 2: l|=((unsigned long)(*((c)++)))<<16;	\

				} }

/* NOTE the pointer is not incremented at the end of this */

#define HOST_c2l_p(c,l,n)	{					\

			l=0; (c)+=n;					\

			switch (n) {					\

			case 3: l =((unsigned long)(*(--(c))))<<16;	\

			case 2: l|=((unsigned long)(*(--(c))))<< 8;	\

			case 1: l|=((unsigned long)(*(--(c))));		\

				} }

#ifndef HOST_l2c

#define HOST_l2c(l,c)	(*((c)++)=(unsigned char)(((l)    )&0xff),	\

			 *((c)++)=(unsigned char)(((l)>> 8)&0xff),	\

			 *((c)++)=(unsigned char)(((l)>>16)&0xff),	\

			 *((c)++)=(unsigned char)(((l)>>24)&0xff),	\

			 l)

#endif

#endif

/*

 * Time for some action:-)

 */

EXPORT_C int HASH_UPDATE (HASH_CTX *c, const void *data_, size_t len)

	{

	const unsigned char *data=data_;

	register HASH_LONG * p;

	register HASH_LONG l;

	size_t sw,sc,ew,ec;

	if (len==0) return 1;

	l=(c->Nl+(((HASH_LONG)len)<<3))&0xffffffffUL;

	/* 95-05-24 eay Fixed a bug with the overflow handling, thanks to

	 * Wei Dai <weidai@eskimo.com> for pointing it out. */

	if (l < c->Nl) /* overflow */

		c->Nh++;

	c->Nh+=(len>>29);	/* might cause compiler warning on 16-bit */

	c->Nl=l;

	if (c->num != 0)

		{

		p=c->data;

		sw=c->num>>2;

		sc=c->num&0x03;

		if ((c->num+len) >= HASH_CBLOCK)

			{

			l=p[sw]; HOST_p_c2l(data,l,sc); p[sw++]=l;

			for (; sw<HASH_LBLOCK; sw++)

				{

				HOST_c2l(data,l); p[sw]=l;

				}

			HASH_BLOCK_HOST_ORDER (c,p,1);

			len-=(HASH_CBLOCK-c->num);

			c->num=0;

			/* drop through and do the rest */

			}

		else

			{

			c->num+=(unsigned int)len;

			if ((sc+len) < 4) /* ugly, add char's to a word */

				{

				l=p[sw]; HOST_p_c2l_p(data,l,sc,len); p[sw]=l;

				}

			else

				{

				ew=(c->num>>2);

				ec=(c->num&0x03);

				if (sc)

					l=p[sw];

				HOST_p_c2l(data,l,sc);

				p[sw++]=l;

				for (; sw < ew; sw++)

					{

					HOST_c2l(data,l); p[sw]=l;

					}

				if (ec)

					{

					HOST_c2l_p(data,l,ec); p[sw]=l;

					}

				}

			return 1;

			}

		}

	sw=len/HASH_CBLOCK;

	if (sw > 0)

		{

#if defined(HASH_BLOCK_DATA_ORDER_ALIGNED)

		/*

		 * Note that HASH_BLOCK_DATA_ORDER_ALIGNED gets defined

		 * only if sizeof(HASH_LONG)==4.

		 */

		if ((((size_t)data)%4) == 0)

			{

			/* data is properly aligned so that we can cast it: */

			HASH_BLOCK_DATA_ORDER_ALIGNED (c,(const HASH_LONG *)data,sw);

			sw*=HASH_CBLOCK;

			data+=sw;

			len-=sw;

			}

		else

#if !defined(HASH_BLOCK_DATA_ORDER)

			while (sw--)

				{

				memcpy (p=c->data,data,HASH_CBLOCK);

				HASH_BLOCK_DATA_ORDER_ALIGNED(c,p,1);

				data+=HASH_CBLOCK;

				len-=HASH_CBLOCK;

				}

#endif

#endif

#if defined(HASH_BLOCK_DATA_ORDER)

			{

			HASH_BLOCK_DATA_ORDER(c,data,sw);

			sw*=HASH_CBLOCK;

			data+=sw;

			len-=sw;

			}

#endif

		}

	if (len!=0)

		{

		p = c->data;

		c->num = len;

		ew=len>>2;	/* words to copy */

		ec=len&0x03;

		for (; ew; ew--,p++)

			{

			HOST_c2l(data,l); *p=l;

			}

		HOST_c2l_p(data,l,ec);

		*p=l;

		}

	return 1;

	}

EXPORT_C void HASH_TRANSFORM (HASH_CTX *c, const unsigned char *data)

	{

#if defined(HASH_BLOCK_DATA_ORDER_ALIGNED)

	if ((((size_t)data)%4) == 0)

		/* data is properly aligned so that we can cast it: */

		HASH_BLOCK_DATA_ORDER_ALIGNED (c,(const HASH_LONG *)data,1);

	else

#if !defined(HASH_BLOCK_DATA_ORDER)

		{

		memcpy (c->data,data,HASH_CBLOCK);

		HASH_BLOCK_DATA_ORDER_ALIGNED (c,c->data,1);

		}

#endif

#endif

#if defined(HASH_BLOCK_DATA_ORDER)

	HASH_BLOCK_DATA_ORDER (c,data,1);

#endif

	}

EXPORT_C int HASH_FINAL (unsigned char *md, HASH_CTX *c)

	{

	register HASH_LONG *p;

	register unsigned long l;

	register int i,j;

	static const unsigned char end[4]={0x80,0x00,0x00,0x00};

	const unsigned char *cp=end;

	/* c->num should definitly have room for at least one more byte. */

	p=c->data;

	i=c->num>>2;

	j=c->num&0x03;

#if 0

	/* purify often complains about the following line as an

	 * Uninitialized Memory Read.  While this can be true, the

	 * following p_c2l macro will reset l when that case is true.

	 * This is because j&0x03 contains the number of 'valid' bytes

	 * already in p[i].  If and only if j&0x03 == 0, the UMR will

	 * occur but this is also the only time p_c2l will do

	 * l= *(cp++) instead of l|= *(cp++)

	 * Many thanks to Alex Tang <altitude@cic.net> for pickup this

	 * 'potential bug' */

#ifdef PURIFY

	if (j==0) p[i]=0; /* Yeah, but that's not the way to fix it:-) */

#endif

	l=p[i];

#else

	l = (j==0) ? 0 : p[i];

#endif

	HOST_p_c2l(cp,l,j); p[i++]=l; /* i is the next 'undefined word' */

	if (i>(HASH_LBLOCK-2)) /* save room for Nl and Nh */

		{

		if (i<HASH_LBLOCK) p[i]=0;

		HASH_BLOCK_HOST_ORDER (c,p,1);

		i=0;

		}

	for (; i<(HASH_LBLOCK-2); i++)

		p[i]=0;

#if   defined(DATA_ORDER_IS_BIG_ENDIAN)

	p[HASH_LBLOCK-2]=c->Nh;

	p[HASH_LBLOCK-1]=c->Nl;

#elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)

	p[HASH_LBLOCK-2]=c->Nl;

	p[HASH_LBLOCK-1]=c->Nh;

#endif

	HASH_BLOCK_HOST_ORDER (c,p,1);

#ifndef HASH_MAKE_STRING

#error "HASH_MAKE_STRING must be defined!"

#else

	HASH_MAKE_STRING(c,md);

#endif

	c->num=0;

	/* clear stuff, HASH_BLOCK may be leaving some stuff on the stack

	 * but I'm not worried :-)

	OPENSSL_cleanse((void *)c,sizeof(HASH_CTX));

	 */

	return 1;

	}

#ifndef MD32_REG_T

#define MD32_REG_T long

/*

 * This comment was originaly written for MD5, which is why it

 * discusses A-D. But it basically applies to all 32-bit digests,

 * which is why it was moved to common header file.

 *

 * In case you wonder why A-D are declared as long and not

 * as MD5_LONG. Doing so results in slight performance

 * boost on LP64 architectures. The catch is we don't

 * really care if 32 MSBs of a 64-bit register get polluted

 * with eventual overflows as we *save* only 32 LSBs in

 * *either* case. Now declaring 'em long excuses the compiler

 * from keeping 32 MSBs zeroed resulting in 13% performance

 * improvement under SPARC Solaris7/64 and 5% under AlphaLinux.

 * Well, to be honest it should say that this *prevents* 

 * performance degradation.

 *				<appro@fy.chalmers.se>

 * Apparently there're LP64 compilers that generate better

 * code if A-D are declared int. Most notably GCC-x86_64

 * generates better code.

 *				<appro@fy.chalmers.se>

 */

#endif