xref: /openbsd/lib/libm/arch/amd64/s_tan.S (revision 3cab2bb3)
1/*	$OpenBSD: s_tan.S,v 1.4 2018/07/03 22:43:34 mortimer 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
11ENTRY(tan)
12	RETGUARD_SETUP(tan, r11)
13	XMM_ONE_ARG_DOUBLE_PROLOGUE
14	fldl	ARG_DOUBLE_ONE
15	fptan
16	fnstsw	%ax
17	andw	$0x400,%ax
18	jnz	1f
19	fstp	%st(0)
20	XMM_DOUBLE_EPILOGUE
21	RETGUARD_CHECK(tan, r11)
22	ret
231:	fldpi
24	fadd	%st(0)
25	fxch	%st(1)
262:	fprem1
27	fstsw	%ax
28	andw	$0x400,%ax
29	jnz	2b
30	fstp	%st(1)
31	fptan
32	fstp	%st(0)
33	XMM_DOUBLE_EPILOGUE
34	RETGUARD_CHECK(tan, r11)
35	ret
36END(tan)
37