Add incomplet long double math support to libmingwex.a

winsup/mingw/mingwex/math/acosl.c

@@ -0,0 +1,25 @@
+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>.
+ * Public domain.
+ *
+ * Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.
+ */
+
+#include <math.h>
+
+long double
+acosl (long double x)
+{
+  long double res;
+
+  /* acosl = atanl (sqrtl(1 - x^2) / x) */
+  asm (	"fld	%%st\n\t"
+	"fmul	%%st(0)\n\t"		/* x^2 */
+	"fld1\n\t"
+	"fsubp\n\t"			/* 1 - x^2 */
+	"fsqrt\n\t"			/* sqrtl (1 - x^2) */
+	"fxch	%%st(1)\n\t"
+	"fpatan"
+	: "=t" (res) : "0" (x) : "st(1)");
+  return res;
+}