s_sinf.c revision 152647
1261287Sdes/* s_sinf.c -- float version of s_sin.c. 2261287Sdes * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 3261287Sdes */ 4261287Sdes 5261287Sdes/* 6261287Sdes * ==================================================== 7261287Sdes * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 8261287Sdes * 9261287Sdes * Developed at SunPro, a Sun Microsystems, Inc. business. 10261287Sdes * Permission to use, copy, modify, and distribute this 11261287Sdes * software is freely granted, provided that this notice 12261287Sdes * is preserved. 13261287Sdes * ==================================================== 14261287Sdes */ 15261287Sdes 16261287Sdes#ifndef lint 17261287Sdesstatic char rcsid[] = "$FreeBSD: head/lib/msun/src/s_sinf.c 152647 2005-11-21 04:57:12Z bde $"; 18261287Sdes#endif 19261287Sdes 20261287Sdes#include "math.h" 21261287Sdes#define INLINE_KERNEL_COSF 22261287Sdes#define INLINE_KERNEL_SINF 23261287Sdes#include "math_private.h" 24261287Sdes#include "k_cosf.c" 25261287Sdes#include "k_sinf.c" 26261287Sdes 27261287Sdes/* Small multiples of pi/2 rounded to double precision. */ 28261287Sdesstatic const double 29261287Sdess1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */ 30261287Sdess2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */ 31261287Sdess3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */ 32261287Sdess4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */ 33261287Sdes 34261287Sdesstatic inline float 35261287Sdes__kernel_cosdf(double x) 36261287Sdes{ 37261287Sdes return __kernel_cosf((float)x, x - (float)x); 38261287Sdes} 39261287Sdes 40261287Sdesstatic inline float 41261287Sdes__kernel_sindf(double x) 42261287Sdes{ 43261287Sdes return __kernel_sinf((float)x, x - (float)x, 1); 44261287Sdes} 45261287Sdes 46261287Sdesfloat 47261287Sdessinf(float x) 48261287Sdes{ 49261287Sdes float y[2]; 50261287Sdes int32_t n, hx, ix; 51261287Sdes 52261287Sdes GET_FLOAT_WORD(hx,x); 53261287Sdes ix = hx & 0x7fffffff; 54261287Sdes 55261287Sdes if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */ 56261287Sdes if(ix<0x39800000) /* |x| < 2**-12 */ 57261287Sdes if(((int)x)==0) return x; /* x with inexact if x != 0 */ 58261287Sdes return __kernel_sinf(x,0.0,0); 59261287Sdes } 60261287Sdes if(ix<=0x407b53d1) { /* |x| <= ~5*pi/4 */ 61261287Sdes if(ix<=0x4016cbe3) { /* |x| <= ~3pi/4 */ 62261287Sdes if(hx>0) 63261287Sdes return __kernel_cosdf(x - s1pio2); 64261287Sdes else 65261287Sdes return -__kernel_cosdf(x + s1pio2); 66261287Sdes } else 67261287Sdes return -__kernel_sindf(x + (hx > 0 ? -s2pio2 : s2pio2)); 68261287Sdes } 69261287Sdes if(ix<=0x40e231d5) { /* |x| <= ~9*pi/4 */ 70261287Sdes if(ix<=0x40afeddf) { /* |x| <= ~7*pi/4 */ 71261287Sdes if(hx>0) 72261287Sdes return -__kernel_cosdf(x - s3pio2); 73261287Sdes else 74261287Sdes return __kernel_cosdf(x + s3pio2); 75261287Sdes } else 76261287Sdes return __kernel_sindf(x + (hx > 0 ? -s4pio2 : s4pio2)); 77261287Sdes } 78261287Sdes 79261287Sdes /* sin(Inf or NaN) is NaN */ 80261287Sdes else if (ix>=0x7f800000) return x-x; 81261287Sdes 82261287Sdes /* general argument reduction needed */ 83261287Sdes else { 84261287Sdes n = __ieee754_rem_pio2f(x,y); 85261287Sdes switch(n&3) { 86261287Sdes case 0: return __kernel_sinf(y[0],y[1],1); 87261287Sdes case 1: return __kernel_cosf(y[0],y[1]); 88261287Sdes case 2: return -__kernel_sinf(y[0],y[1],1); 89261287Sdes default: 90261287Sdes return -__kernel_cosf(y[0],y[1]); 91261287Sdes } 92261287Sdes } 93261287Sdes} 94261287Sdes