12116Sjkh/* s_tanf.c -- float version of s_tan.c. 22116Sjkh * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 3152870Sbde * Optimized by Bruce D. Evans. 42116Sjkh */ 52116Sjkh 62116Sjkh/* 72116Sjkh * ==================================================== 82116Sjkh * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 92116Sjkh * 102116Sjkh * Developed at SunPro, a Sun Microsystems, Inc. business. 112116Sjkh * Permission to use, copy, modify, and distribute this 128870Srgrimes * software is freely granted, provided that this notice 132116Sjkh * is preserved. 142116Sjkh * ==================================================== 152116Sjkh */ 162116Sjkh 17176451Sdas#include <sys/cdefs.h> 18176451Sdas__FBSDID("$FreeBSD$"); 192116Sjkh 20176569Sbde#include <float.h> 21176569Sbde 222116Sjkh#include "math.h" 23152870Sbde#define INLINE_KERNEL_TANDF 24176569Sbde#define INLINE_REM_PIO2F 252116Sjkh#include "math_private.h" 26176569Sbde#include "e_rem_pio2f.c" 27152647Sbde#include "k_tanf.c" 282116Sjkh 29152596Sbde/* Small multiples of pi/2 rounded to double precision. */ 30152596Sbdestatic const double 31152596Sbdet1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */ 32152596Sbdet2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */ 33152596Sbdet3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */ 34152596Sbdet4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */ 35152596Sbde 3697413Salfredfloat 3797413Salfredtanf(float x) 382116Sjkh{ 39176552Sbde double y; 40152596Sbde int32_t n, hx, ix; 412116Sjkh 42152596Sbde GET_FLOAT_WORD(hx,x); 43152596Sbde ix = hx & 0x7fffffff; 442116Sjkh 45152540Sbde if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */ 46152540Sbde if(ix<0x39800000) /* |x| < 2**-12 */ 47152540Sbde if(((int)x)==0) return x; /* x with inexact if x != 0 */ 48152713Sbde return __kernel_tandf(x,1); 49151969Sbde } 50152596Sbde if(ix<=0x407b53d1) { /* |x| ~<= 5*pi/4 */ 51152596Sbde if(ix<=0x4016cbe3) /* |x| ~<= 3pi/4 */ 52152596Sbde return __kernel_tandf(x + (hx>0 ? -t1pio2 : t1pio2), -1); 53152596Sbde else 54152596Sbde return __kernel_tandf(x + (hx>0 ? -t2pio2 : t2pio2), 1); 55152596Sbde } 56152596Sbde if(ix<=0x40e231d5) { /* |x| ~<= 9*pi/4 */ 57152596Sbde if(ix<=0x40afeddf) /* |x| ~<= 7*pi/4 */ 58152596Sbde return __kernel_tandf(x + (hx>0 ? -t3pio2 : t3pio2), -1); 59152596Sbde else 60152596Sbde return __kernel_tandf(x + (hx>0 ? -t4pio2 : t4pio2), 1); 61152596Sbde } 622116Sjkh 632116Sjkh /* tan(Inf or NaN) is NaN */ 64152540Sbde else if (ix>=0x7f800000) return x-x; 652116Sjkh 66152596Sbde /* general argument reduction needed */ 672116Sjkh else { 68176552Sbde n = __ieee754_rem_pio2f(x,&y); 69152540Sbde /* integer parameter: 1 -- n even; -1 -- n odd */ 70176552Sbde return __kernel_tandf(y,1-((n&1)<<1)); 712116Sjkh } 722116Sjkh} 73