153437Sbostic /*- 253437Sbostic * Copyright (c) 1992 The Regents of the University of California. 353437Sbostic * All rights reserved. 453437Sbostic * 553794Sbostic * This software was developed by the Computer Systems Engineering group 653794Sbostic * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 753794Sbostic * contributed to Berkeley. 853794Sbostic * 953437Sbostic * %sccs.include.redist.c% 1053437Sbostic */ 1153437Sbostic 1253437Sbostic #if defined(LIBC_SCCS) && !defined(lint) 13*54431Sbostic static char sccsid[] = "@(#)fixunsdfdi.c 5.4 (Berkeley) 06/25/92"; 1453437Sbostic #endif /* LIBC_SCCS and not lint */ 1553437Sbostic 1653794Sbostic #include "quad.h" 1753459Sbostic 1853794Sbostic #define ONE_FOURTH (1 << (LONG_BITS - 2)) 1953794Sbostic #define ONE_HALF (ONE_FOURTH * 2.0) 2053794Sbostic #define ONE (ONE_FOURTH * 4.0) 2153459Sbostic 2253794Sbostic /* 2353794Sbostic * Convert double to (unsigned) quad. 2453794Sbostic * Not sure what to do with negative numbers---for now, anything out 2553794Sbostic * of range becomes UQUAD_MAX. 2653794Sbostic */ 27*54431Sbostic u_quad_t 28*54431Sbostic __fixunsdfdi(x) 29*54431Sbostic double x; 3053437Sbostic { 3153794Sbostic double toppart; 3253794Sbostic union uu t; 3353437Sbostic 3453794Sbostic if (x < 0) 3553794Sbostic return (UQUAD_MAX); /* ??? should be 0? ERANGE??? */ 3653794Sbostic if (x >= UQUAD_MAX) 3753794Sbostic return (UQUAD_MAX); 3853794Sbostic /* 3953794Sbostic * Get the upper part of the result. Note that the divide 4053794Sbostic * may round up; we want to avoid this if possible, so we 4153794Sbostic * subtract `1/2' first. 4253794Sbostic */ 4353794Sbostic toppart = (x - ONE_HALF) / ONE; 4453794Sbostic /* 45*54431Sbostic * Now build a u_quad_t out of the top part. The difference 4653794Sbostic * between x and this is the bottom part (this may introduce 4753794Sbostic * a few fuzzy bits, but what the heck). With any luck this 4853794Sbostic * difference will be nonnegative: x should wind up in the 4953794Sbostic * range [0..ULONG_MAX]. For paranoia, we assume [LONG_MIN.. 5053794Sbostic * 2*ULONG_MAX] instead. 5153794Sbostic */ 5253794Sbostic t.ul[H] = (unsigned long)toppart; 5353794Sbostic t.ul[L] = 0; 5453794Sbostic x -= (double)t.uq; 5553794Sbostic if (x < 0) { 5653794Sbostic t.ul[H]--; 5753794Sbostic x += ULONG_MAX; 5853794Sbostic } 5953794Sbostic if (x > ULONG_MAX) { 6053794Sbostic t.ul[H]++; 6153794Sbostic x -= ULONG_MAX; 6253794Sbostic } 6353794Sbostic t.ul[L] = (u_long)x; 6453794Sbostic return (t.uq); 6553437Sbostic } 66