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/* k_cosf.c -- float version of k_cos.c |
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* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
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*/ |
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/* |
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* ==================================================== |
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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* |
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* Developed at SunPro, a Sun Microsystems, Inc. business. |
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* Permission to use, copy, modify, and distribute this |
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* software is freely granted, provided that this notice |
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* is preserved. |
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* ==================================================== |
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*/ |
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#include "math.h" |
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#include "math_private.h" |
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static const float |
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one = 1.0000000000e+00, /* 0x3f800000 */ |
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C1 = 4.1666667908e-02, /* 0x3d2aaaab */ |
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C2 = -1.3888889225e-03, /* 0xbab60b61 */ |
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C3 = 2.4801587642e-05, /* 0x37d00d01 */ |
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C4 = -2.7557314297e-07, /* 0xb493f27c */ |
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C5 = 2.0875723372e-09, /* 0x310f74f6 */ |
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C6 = -1.1359647598e-11; /* 0xad47d74e */ |
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float |
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__kernel_cosf(float x, float y) |
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{ |
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float a,hz,z,r,qx; |
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int32_t ix; |
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GET_FLOAT_WORD(ix,x); |
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ix &= 0x7fffffff; /* ix = |x|'s high word*/ |
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if(ix<0x32000000) { /* if x < 2**27 */ |
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if(((int)x)==0) return one; /* generate inexact */ |
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} |
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z = x*x; |
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r = z*(C1+z*(C2+z*(C3+z*(C4+z*(C5+z*C6))))); |
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if(ix < 0x3e99999a) /* if |x| < 0.3 */ |
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return one - ((float)0.5*z - (z*r - x*y)); |
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else { |
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if(ix > 0x3f480000) { /* x > 0.78125 */ |
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qx = (float)0.28125; |
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} else { |
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SET_FLOAT_WORD(qx,ix-0x01000000); /* x/4 */ |
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} |
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hz = (float)0.5*z-qx; |
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a = one-qx; |
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return a - (hz - (z*r-x*y)); |
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} |
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} |