root/Zend/zend_multiply.h

INCLUDED FROM

/*
   +----------------------------------------------------------------------+
   | Zend Engine                                                          |
   +----------------------------------------------------------------------+
   | Copyright (c) 1998-2008 Zend Technologies Ltd. (http://www.zend.com) |
   +----------------------------------------------------------------------+
   | This source file is subject to version 2.00 of the Zend license,     |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.zend.com/license/2_00.txt.                                |
   | If you did not receive a copy of the Zend license and are unable to  |
   | obtain it through the world-wide-web, please send a note to          |
   | license@zend.com so we can mail you a copy immediately.              |
   +----------------------------------------------------------------------+
   | Authors: Sascha Schumann <sascha@schumann.cx>                        |
   |          Ard Biesheuvel <ard@ard.nu>                                 |
   +----------------------------------------------------------------------+
*/

/* $Id: zend_multiply.h,v 1.10.2.1.2.3 2007/12/31 07:20:03 sebastian Exp $ */

#if defined(__i386__) && defined(__GNUC__)

#define ZEND_SIGNED_MULTIPLY_LONG(a, b, lval, dval, usedval) do {       \
        long __tmpvar;                                                                                                  \
        __asm__ ("imul %3,%0\n"                                                                                 \
                "adc $0,%1"                                                                                             \
                        : "=r"(__tmpvar),"=r"(usedval)                                                  \
                        : "0"(a), "r"(b), "1"(0));                                                              \
        if (usedval) (dval) = (double) (a) * (double) (b);                              \
        else (lval) = __tmpvar;                                                                                 \
} while (0)

#else

#define ZEND_SIGNED_MULTIPLY_LONG(a, b, lval, dval, usedval) do {               \
        long   __lres  = (a) * (b);                                                                                     \
        long double __dres  = (long double)(a) * (long double)(b);                                                      \
        long double __delta = (long double) __lres - __dres;                                                    \
        if ( ((usedval) = (( __dres + __delta ) != __dres))) {                          \
                (dval) = __dres;                                                                                                \
        } else {                                                                                                                        \
                (lval) = __lres;                                                                                                \
        }                                                                                                                                       \
} while (0)

#endif