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author | PikalaxALT <pikalaxalt@gmail.com> | 2017-12-15 09:38:53 -0500 |
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committer | PikalaxALT <pikalaxalt@gmail.com> | 2017-12-15 09:39:34 -0500 |
commit | f95a4a932476be2ba99e2fd081e8d2bc6ea12813 (patch) | |
tree | 75f67192cb2d7b7b575c94edda318e475239b63c /newlib/libm/mathfp/s_atan.c | |
parent | f60aca96985e68c7d8a52eb7bc955fb80e132f73 (diff) |
Import newlib and create makefile
Diffstat (limited to 'newlib/libm/mathfp/s_atan.c')
-rw-r--r-- | newlib/libm/mathfp/s_atan.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/newlib/libm/mathfp/s_atan.c b/newlib/libm/mathfp/s_atan.c new file mode 100644 index 0000000..b8e633e --- /dev/null +++ b/newlib/libm/mathfp/s_atan.c @@ -0,0 +1,83 @@ + +/* @(#)z_atan.c 1.0 98/08/13 */ + +/* +FUNCTION + <<atan>>, <<atanf>>---arc tangent + +INDEX + atan +INDEX + atanf + +ANSI_SYNOPSIS + #include <math.h> + double atan(double <[x]>); + float atanf(float <[x]>); + +TRAD_SYNOPSIS + #include <math.h> + double atan(<[x]>); + double <[x]>; + + float atanf(<[x]>); + float <[x]>; + +DESCRIPTION + +<<atan>> computes the inverse tangent (arc tangent) of the input value. + +<<atanf>> is identical to <<atan>>, save that it operates on <<floats>>. + +RETURNS +@ifinfo +<<atan>> returns a value in radians, in the range of -pi/2 to pi/2. +@end ifinfo +@tex +<<atan>> returns a value in radians, in the range of $-\pi/2$ to $\pi/2$. +@end tex + +PORTABILITY +<<atan>> is ANSI C. <<atanf>> is an extension. + +*/ + +/****************************************************************** + * Arctangent + * + * Input: + * x - floating point value + * + * Output: + * arctan of x + * + * Description: + * This routine returns the arctan of x. + * + *****************************************************************/ + +#include "fdlibm.h" +#include "zmath.h" + +#ifndef _DOUBLE_IS_32BITS + +double +_DEFUN (atan, (double), + double x) +{ + switch (numtest (x)) + { + case NAN: + errno = EDOM; + return (x); + case INF: + /* this should check to see if neg NaN or pos NaN... */ + return (__PI_OVER_TWO); + case 0: + return (0.0); + default: + return (atangent (x, 0, 0, 0)); + } +} + +#endif /* _DOUBLE_IS_32BITS */ |