summaryrefslogtreecommitdiff
path: root/src/math/s_atanf.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/math/s_atanf.c')
-rw-r--r--src/math/s_atanf.c95
1 files changed, 0 insertions, 95 deletions
diff --git a/src/math/s_atanf.c b/src/math/s_atanf.c
deleted file mode 100644
index 03067e18..00000000
--- a/src/math/s_atanf.c
+++ /dev/null
@@ -1,95 +0,0 @@
-/* s_atanf.c -- float version of s_atan.c.
- * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
- */
-
-/*
- * ====================================================
- * Copyright (C) 1993 by 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.
- * ====================================================
- */
-
-#include <math.h>
-#include "math_private.h"
-
-static const float atanhi[] = {
- 4.6364760399e-01, /* atan(0.5)hi 0x3eed6338 */
- 7.8539812565e-01, /* atan(1.0)hi 0x3f490fda */
- 9.8279368877e-01, /* atan(1.5)hi 0x3f7b985e */
- 1.5707962513e+00, /* atan(inf)hi 0x3fc90fda */
-};
-
-static const float atanlo[] = {
- 5.0121582440e-09, /* atan(0.5)lo 0x31ac3769 */
- 3.7748947079e-08, /* atan(1.0)lo 0x33222168 */
- 3.4473217170e-08, /* atan(1.5)lo 0x33140fb4 */
- 7.5497894159e-08, /* atan(inf)lo 0x33a22168 */
-};
-
-static const float aT[] = {
- 3.3333334327e-01, /* 0x3eaaaaaa */
- -2.0000000298e-01, /* 0xbe4ccccd */
- 1.4285714924e-01, /* 0x3e124925 */
- -1.1111110449e-01, /* 0xbde38e38 */
- 9.0908870101e-02, /* 0x3dba2e6e */
- -7.6918758452e-02, /* 0xbd9d8795 */
- 6.6610731184e-02, /* 0x3d886b35 */
- -5.8335702866e-02, /* 0xbd6ef16b */
- 4.9768779427e-02, /* 0x3d4bda59 */
- -3.6531571299e-02, /* 0xbd15a221 */
- 1.6285819933e-02, /* 0x3c8569d7 */
-};
-
- static const float
-one = 1.0,
-huge = 1.0e30;
-
-float
-atanf(float x)
-{
- float w,s1,s2,z;
- int32_t ix,hx,id;
-
- GET_FLOAT_WORD(hx,x);
- ix = hx&0x7fffffff;
- if(ix>=0x50800000) { /* if |x| >= 2^34 */
- if(ix>0x7f800000)
- return x+x; /* NaN */
- if(hx>0) return atanhi[3]+atanlo[3];
- else return -atanhi[3]-atanlo[3];
- } if (ix < 0x3ee00000) { /* |x| < 0.4375 */
- if (ix < 0x31000000) { /* |x| < 2^-29 */
- if(huge+x>one) return x; /* raise inexact */
- }
- id = -1;
- } else {
- x = fabsf(x);
- if (ix < 0x3f980000) { /* |x| < 1.1875 */
- if (ix < 0x3f300000) { /* 7/16 <=|x|<11/16 */
- id = 0; x = ((float)2.0*x-one)/((float)2.0+x);
- } else { /* 11/16<=|x|< 19/16 */
- id = 1; x = (x-one)/(x+one);
- }
- } else {
- if (ix < 0x401c0000) { /* |x| < 2.4375 */
- id = 2; x = (x-(float)1.5)/(one+(float)1.5*x);
- } else { /* 2.4375 <= |x| < 2^66 */
- id = 3; x = -(float)1.0/x;
- }
- }}
- /* end of argument reduction */
- z = x*x;
- w = z*z;
- /* break sum from i=0 to 10 aT[i]z**(i+1) into odd and even poly */
- s1 = z*(aT[0]+w*(aT[2]+w*(aT[4]+w*(aT[6]+w*(aT[8]+w*aT[10])))));
- s2 = w*(aT[1]+w*(aT[3]+w*(aT[5]+w*(aT[7]+w*aT[9]))));
- if (id<0) return x - x*(s1+s2);
- else {
- z = atanhi[id] - ((x*(s1+s2) - atanlo[id]) - x);
- return (hx<0)? -z:z;
- }
-}