Mercurial > mxe-octave
view src/build-msvctools/math/acoshf.c @ 3061:f8299bb6c872
Initial support for native MSVC compilation.
* add MSVC support files: compiler wrappers and support libraries
* adapt libiconv to work with MSVC
* adapt gettext to work with MSVC
author | Michael Goffioul <michael.goffioul@gmail.com> |
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date | Mon, 17 Jun 2013 22:43:11 -0400 |
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#include <math.h> #include <errno.h> #include "fastmath.h" /* acosh(x) = log (x + sqrt(x * x - 1)) */ float acoshf (float x) { if (isnan (x)) return x; if (x < 1.0f) { errno = EDOM; return nan(""); } if (x > 0x1p32f) /* Avoid overflow (and unnecessary calculation when sqrt (x * x - 1) == x). GCC optimizes by replacing the long double M_LN2 const with a fldln2 insn. */ return __fast_log (x) + 6.9314718055994530941723E-1L; /* Since x >= 1, the arg to log will always be greater than the fyl2xp1 limit (approx 0.29) so just use logl. */ return __fast_log (x + __fast_sqrt((x + 1.0) * (x - 1.0))); }