glibc/sysdeps/i386/fpu/e_acos.S
2012-04-30 18:56:39 +00:00

26 lines
613 B
ArmAsm

/*
* 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)