Index: fusl/src/math/acoshl.c |
diff --git a/fusl/src/math/acoshl.c b/fusl/src/math/acoshl.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..8d4b43f64cdd899877bf39f43c7657f1f3b3f17c |
--- /dev/null |
+++ b/fusl/src/math/acoshl.c |
@@ -0,0 +1,29 @@ |
+#include "libm.h" |
+ |
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 |
+long double acoshl(long double x) |
+{ |
+ return acosh(x); |
+} |
+#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 |
+/* acosh(x) = log(x + sqrt(x*x-1)) */ |
+long double acoshl(long double x) |
+{ |
+ union ldshape u = {x}; |
+ int e = u.i.se & 0x7fff; |
+ |
+ if (e < 0x3fff + 1) |
+ /* |x| < 2, invalid if x < 1 or nan */ |
+ return log1pl(x-1 + sqrtl((x-1)*(x-1)+2*(x-1))); |
+ if (e < 0x3fff + 32) |
+ /* |x| < 0x1p32 */ |
+ return logl(2*x - 1/(x+sqrtl(x*x-1))); |
+ return logl(x) + 0.693147180559945309417232121458176568L; |
+} |
+#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 |
+// TODO: broken implementation to make things compile |
+long double acoshl(long double x) |
+{ |
+ return acosh(x); |
+} |
+#endif |