1/* $OpenBSD: e_acos.S,v 1.4 2008/09/07 20:36:08 martynas Exp $ */ 2/* 3 * Written by J.T. Conklin <jtc@NetBSD.org>. 4 * Public domain. 5 */ 6 7#include <machine/asm.h> 8 9#include "abi.h" 10 11/* acos = atan (sqrt(1 - x^2) / x) */ 12ENTRY(acos) 13 XMM_ONE_ARG_DOUBLE_PROLOGUE 14 fldl ARG_DOUBLE_ONE /* x */ 15 fld %st(0) 16 fmul %st(0) /* x^2 */ 17 fld1 18 fsubp /* 1 - x^2 */ 19 fsqrt /* sqrt (1 - x^2) */ 20 fxch %st(1) 21 fpatan 22 XMM_DOUBLE_EPILOGUE 23 ret 24