1 /* $NetBSD: fixunsdfdi.c,v 1.7 2003/08/07 16:43:16 agc 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. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)fixunsdfdi.c 8.1 (Berkeley) 6/4/93"; 40 #else 41 __RCSID("$NetBSD: fixunsdfdi.c,v 1.7 2003/08/07 16:43:16 agc Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include "quad.h" 46 47 #define ONE_FOURTH ((int)1 << (INT_BITS - 2)) 48 #define ONE_HALF (ONE_FOURTH * 2.0) 49 #define ONE (ONE_FOURTH * 4.0) 50 51 /* 52 * Convert double to (unsigned) quad. 53 * Not sure what to do with negative numbers---for now, anything out 54 * of range becomes UQUAD_MAX. 55 */ 56 u_quad_t 57 __fixunsdfdi(x) 58 double x; 59 { 60 union uu t; 61 unsigned int tmp; 62 63 if (x < 0) 64 return (UQUAD_MAX); /* ??? should be 0? ERANGE??? */ 65 #ifdef notdef /* this falls afoul of a GCC bug */ 66 if (x >= UQUAD_MAX) 67 return (UQUAD_MAX); 68 #else /* so we wire in 2^64-1 instead */ 69 if (x >= 18446744073709551615.0) /* XXX */ 70 return (UQUAD_MAX); 71 #endif 72 /* 73 * Now we know that 0 <= x <= 18446744073709549568. The upper 74 * limit is one ulp less than 18446744073709551615 tested for above. 75 * Dividing this by 2^32 will *not* round irrespective of any 76 * rounding modes (except if the result is an IEEE denorm). 77 * Furthermore, the quotient will fit into a 32-bit integer. 78 */ 79 tmp = x / ONE; 80 t.ul[L] = (unsigned int) (x - tmp * ONE); 81 t.ul[H] = tmp; 82 return (t.uq); 83 } 84