From bd5969fc876a10b18613302db7087ef3c40f18e1 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Thu, 7 Mar 2024 17:28:00 -0500 Subject: lib: Add mlibc Signed-off-by: Ian Moffett --- lib/mlibc/options/ansi/musl-generic-math/asinhf.c | 28 +++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 lib/mlibc/options/ansi/musl-generic-math/asinhf.c (limited to 'lib/mlibc/options/ansi/musl-generic-math/asinhf.c') diff --git a/lib/mlibc/options/ansi/musl-generic-math/asinhf.c b/lib/mlibc/options/ansi/musl-generic-math/asinhf.c new file mode 100644 index 0000000..fc9f091 --- /dev/null +++ b/lib/mlibc/options/ansi/musl-generic-math/asinhf.c @@ -0,0 +1,28 @@ +#include "libm.h" + +/* asinh(x) = sign(x)*log(|x|+sqrt(x*x+1)) ~= x - x^3/6 + o(x^5) */ +float asinhf(float x) +{ + union {float f; uint32_t i;} u = {.f = x}; + uint32_t i = u.i & 0x7fffffff; + unsigned s = u.i >> 31; + + /* |x| */ + u.i = i; + x = u.f; + + if (i >= 0x3f800000 + (12<<23)) { + /* |x| >= 0x1p12 or inf or nan */ + x = logf(x) + 0.693147180559945309417232121458176568f; + } else if (i >= 0x3f800000 + (1<<23)) { + /* |x| >= 2 */ + x = logf(2*x + 1/(sqrtf(x*x+1)+x)); + } else if (i >= 0x3f800000 - (12<<23)) { + /* |x| >= 0x1p-12, up to 1.6ulp error in [0.125,0.5] */ + x = log1pf(x + x*x/(sqrtf(x*x+1)+1)); + } else { + /* |x| < 0x1p-12, raise inexact if x!=0 */ + FORCE_EVAL(x + 0x1p120f); + } + return s ? -x : x; +} -- cgit v1.2.3