1 /** 2 * This file has no copyright assigned and is placed in the Public Domain. 3 * This file is part of the mingw-w64 runtime package. 4 * No warranty is given; refer to the file DISCLAIMER.PD within this package. 5 */ 6 7 #include <math.h> 8 acoshf(float x)9float acoshf(float x) 10 { 11 if (x < 1.0) 12 return NAN; 13 if (isinf(x*x)) 14 return logf(2) + logf(x); 15 return logf(x + sqrtf(x*x - 1)); 16 } 17