1 /* $NetBSD: fixunsdfdi.c,v 1.6 2002/10/20 10:15:47 scw Exp $ */ 2 3 /*- 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 */ 39 40 #include <sys/cdefs.h> 41 #if defined(LIBC_SCCS) && !defined(lint) 42 #if 0 43 static char sccsid[] = "@(#)fixunsdfdi.c 8.1 (Berkeley) 6/4/93"; 44 #else 45 __RCSID("$NetBSD: fixunsdfdi.c,v 1.6 2002/10/20 10:15:47 scw Exp $"); 46 #endif 47 #endif /* LIBC_SCCS and not lint */ 48 49 #include "quad.h" 50 51 #define ONE_FOURTH ((int)1 << (INT_BITS - 2)) 52 #define ONE_HALF (ONE_FOURTH * 2.0) 53 #define ONE (ONE_FOURTH * 4.0) 54 55 /* 56 * Convert double to (unsigned) quad. 57 * Not sure what to do with negative numbers---for now, anything out 58 * of range becomes UQUAD_MAX. 59 */ 60 u_quad_t 61 __fixunsdfdi(x) 62 double x; 63 { 64 union uu t; 65 unsigned int tmp; 66 67 if (x < 0) 68 return (UQUAD_MAX); /* ??? should be 0? ERANGE??? */ 69 #ifdef notdef /* this falls afoul of a GCC bug */ 70 if (x >= UQUAD_MAX) 71 return (UQUAD_MAX); 72 #else /* so we wire in 2^64-1 instead */ 73 if (x >= 18446744073709551615.0) /* XXX */ 74 return (UQUAD_MAX); 75 #endif 76 /* 77 * Now we know that 0 <= x <= 18446744073709549568. The upper 78 * limit is one ulp less than 18446744073709551615 tested for above. 79 * Dividing this by 2^32 will *not* round irrespective of any 80 * rounding modes (except if the result is an IEEE denorm). 81 * Furthermore, the quotient will fit into a 32-bit integer. 82 */ 83 tmp = x / ONE; 84 t.ul[L] = (unsigned int) (x - tmp * ONE); 85 t.ul[H] = tmp; 86 return (t.uq); 87 } 88