| b_log.c (138924) | b_log.c (150318) |
|---|---|
| 1/* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright --- 21 unchanged lines hidden (view full) --- 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34#ifndef lint 35static char sccsid[] = "@(#)log.c 8.2 (Berkeley) 11/30/93"; 36#endif /* not lint */ 37#include <sys/cdefs.h> | 1/* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright --- 21 unchanged lines hidden (view full) --- 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34#ifndef lint 35static char sccsid[] = "@(#)log.c 8.2 (Berkeley) 11/30/93"; 36#endif /* not lint */ 37#include <sys/cdefs.h> |
| 38__FBSDID("$FreeBSD: head/lib/msun/bsdsrc/b_log.c 138924 2004-12-16 20:40:37Z das $"); | 38__FBSDID("$FreeBSD: head/lib/msun/bsdsrc/b_log.c 150318 2005-09-19 11:28:19Z bde $"); |
| 39 40#include <math.h> 41#include <errno.h> 42 43#include "mathimpl.h" 44 45/* Table-driven natural logarithm. 46 * --- 25 unchanged lines hidden (view full) --- 72 * (This is done differently in the original paper) 73 * 74 * Special cases: 75 * 0 return signalling -Inf 76 * neg return signalling NaN 77 * +Inf return +Inf 78*/ 79 | 39 40#include <math.h> 41#include <errno.h> 42 43#include "mathimpl.h" 44 45/* Table-driven natural logarithm. 46 * --- 25 unchanged lines hidden (view full) --- 72 * (This is done differently in the original paper) 73 * 74 * Special cases: 75 * 0 return signalling -Inf 76 * neg return signalling NaN 77 * +Inf return +Inf 78*/ 79 |
| 80#define endian (((*(int *) &one)) ? 1 : 0) 81#define TRUNC(x) *(((int *) &x) + endian) &= 0xf8000000 82 | |
| 83#define N 128 84 85/* Table of log(Fj) = logF_head[j] + logF_tail[j], for Fj = 1+j/128. 86 * Used for generation of extend precision logarithms. 87 * The constant 35184372088832 is 2^45, so the divide is exact. 88 * It ensures correct reading of logF_head, even for inaccurate 89 * decimal-to-binary conversion routines. (Everybody gets the 90 * right answer for integers less than 2^53.) --- 342 unchanged lines hidden (view full) --- 433struct Double 434#ifdef _ANSI_SOURCE 435__log__D(double x) 436#else 437__log__D(x) double x; 438#endif 439{ 440 int m, j; | 80#define N 128 81 82/* Table of log(Fj) = logF_head[j] + logF_tail[j], for Fj = 1+j/128. 83 * Used for generation of extend precision logarithms. 84 * The constant 35184372088832 is 2^45, so the divide is exact. 85 * It ensures correct reading of logF_head, even for inaccurate 86 * decimal-to-binary conversion routines. (Everybody gets the 87 * right answer for integers less than 2^53.) --- 342 unchanged lines hidden (view full) --- 430struct Double 431#ifdef _ANSI_SOURCE 432__log__D(double x) 433#else 434__log__D(x) double x; 435#endif 436{ 437 int m, j; |
| 441 double F, f, g, q, u, v, u2, one = 1.0; | 438 double F, f, g, q, u, v, u2; |
| 442 volatile double u1; 443 struct Double r; 444 445 /* Argument reduction: 1 <= g < 2; x/2^m = g; */ 446 /* y = F*(1 + f/F) for |f| <= 2^-8 */ 447 448 m = logb(x); 449 g = ldexp(x, -m); --- 27 unchanged lines hidden --- | 439 volatile double u1; 440 struct Double r; 441 442 /* Argument reduction: 1 <= g < 2; x/2^m = g; */ 443 /* y = F*(1 + f/F) for |f| <= 2^-8 */ 444 445 m = logb(x); 446 g = ldexp(x, -m); --- 27 unchanged lines hidden --- |