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/*
 * Written by J.T. Conklin <jtc@netbsd.org>.
 * Public domain.
 */

#include <machine/asm.h>
#include <libm-alias-finite.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)
libm_alias_finite (__ieee754_acos, __acos)