diff options
Diffstat (limited to 'lib/msun/src')
| -rw-r--r-- | lib/msun/src/k_tanf.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/lib/msun/src/k_tanf.c b/lib/msun/src/k_tanf.c index 35bbe61..41c522c 100644 --- a/lib/msun/src/k_tanf.c +++ b/lib/msun/src/k_tanf.c @@ -4,9 +4,8 @@ /* * ==================================================== - * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * Copyright 2004 Sun Microsystems, Inc. All Rights Reserved. * - * Developed at SunPro, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this * software is freely granted, provided that this notice * is preserved. @@ -46,12 +45,29 @@ __kernel_tanf(float x, float y, int iy) int32_t ix,hx; GET_FLOAT_WORD(hx,x); ix = hx&0x7fffffff; /* high word of |x| */ - if(ix<0x31800000) /* x < 2**-28 */ - {if((int)x==0) { /* generate inexact */ - if((ix|(iy+1))==0) return one/fabsf(x); - else return (iy==1)? x: -one/x; - } - } + if(ix<0x31800000) { /* x < 2**-28 */ + if ((int) x == 0) { /* generate inexact */ + if ((ix | (iy + 1)) == 0) + return one / fabsf(x); + else { + if (iy == 1) + return x; + else { /* compute -1 / (x+y) carefully */ + double a, t; + + z = w = x + y; + GET_FLOAT_WORD(ix, z); + SET_FLOAT_WORD(z, ix & 0xfffff000); + v = y - (z - x); + t = a = -one / w; + GET_FLOAT_WORD(ix, t); + SET_FLOAT_WORD(t, ix & 0xfffff000); + s = one + t * z; + return t + a * (s + t * v); + } + } + } + } if(ix>=0x3f2ca140) { /* |x|>=0.6744 */ if(hx<0) {x = -x; y = -y;} z = pio4-x; |
