about summary refs log tree commit diff
path: root/REORG.TODO/sysdeps/i386/fpu/e_acos.S
diff options
context:
space:
mode:
Diffstat (limited to 'REORG.TODO/sysdeps/i386/fpu/e_acos.S')
-rw-r--r--REORG.TODO/sysdeps/i386/fpu/e_acos.S25
1 files changed, 25 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/i386/fpu/e_acos.S b/REORG.TODO/sysdeps/i386/fpu/e_acos.S
new file mode 100644
index 0000000000..586c7fc406
--- /dev/null
+++ b/REORG.TODO/sysdeps/i386/fpu/e_acos.S
@@ -0,0 +1,25 @@
+/*
+ * Written by J.T. Conklin <jtc@netbsd.org>.
+ * Public domain.
+ */
+
+#include <machine/asm.h>
+
+RCSID("$NetBSD: e_acos.S,v 1.4 1995/05/08 23:44:37 jtc Exp $")
+
+/* acos = atan (sqrt((1-x) (1+x)) / x) */
+ENTRY(__ieee754_acos)
+	fldl	4(%esp)			/* x */
+	fld	%st			/* x : x */
+	fld1				/* 1 : x : x */
+	fsubp				/* 1 - x : x */
+	fld1				/* 1 : 1 - x : x */
+	fadd	%st(2)			/* 1 + x : 1 - x : x */
+	fmulp				/* 1 - x^2 : x */
+	fsqrt				/* sqrt (1 - x^2) : x */
+	fabs
+	fxch	%st(1)			/* x : sqrt (1 - x^2) */
+	fpatan				/* atan (sqrt(1 - x^2) / x) */
+	ret
+END (__ieee754_acos)
+strong_alias (__ieee754_acos, __acos_finite)