BSD 3 development

Work on file usr/src/lib/libm/asin.c

Synthesized-from: 3bsd

diff --git a/usr/src/lib/libm/asin.c b/usr/src/lib/libm/asin.c
new file mode 100644 (file)
index 0000000..cacb6b4
--- /dev/null
+++ b/usr/src/lib/libm/asin.c
@@ -0,0 +1,48 @@
+/*
+       asin(arg) and acos(arg) return the arcsin, arccos,
+       respectively of their arguments.
+
+       Arctan is called after appropriate range reduction.
+*/
+
+#include       <errno.h>
+int errno;
+double atan();
+double sqrt();
+static double pio2     = 1.570796326794896619;
+
+double
+asin(arg) double arg; {
+
+       double sign, temp;
+
+       sign = 1.;
+       if(arg <0){
+               arg = -arg;
+               sign = -1.;
+       }
+
+       if(arg > 1.){
+               errno = EDOM;
+               return(0.);
+       }
+
+       temp = sqrt(1. - arg*arg);
+       if(arg > 0.7)
+               temp = pio2 - atan(temp/arg);
+       else
+               temp = atan(arg/temp);
+
+       return(sign*temp);
+}
+
+double
+acos(arg) double arg; {
+
+       if((arg > 1.) || (arg < -1.)){
+               errno = EDOM;
+               return(0.);
+       }
+
+       return(pio2 - asin(arg));
+}