xref: /csrg-svn/lib/libm/vax/sincos.s (revision 34125)
124570Szliu# Copyright (c) 1985 Regents of the University of California.
2*34125Sbostic# All rights reserved.
324570Szliu#
4*34125Sbostic# Redistribution and use in source and binary forms are permitted
5*34125Sbostic# provided that this notice is preserved and that due credit is given
6*34125Sbostic# to the University of California at Berkeley. The name of the University
7*34125Sbostic# may not be used to endorse or promote products derived from this
8*34125Sbostic# software without specific prior written permission. This software
9*34125Sbostic# is provided ``as is'' without express or implied warranty.
10*34125Sbostic#
11*34125Sbostic# All recipients should regard themselves as participants in an ongoing
12*34125Sbostic# research project and hence should feel obligated to report their
13*34125Sbostic# experiences (good or bad) with these elementary function codes, using
14*34125Sbostic# the sendbug(8) program, to the authors.
15*34125Sbostic#
16*34125Sbostic#	@(#)sincos.s	5.2 (Berkeley) 04/29/88
17*34125Sbostic#
1824729Selefunt	.data
1924729Selefunt	.align	2
2024729Selefunt_sccsid:
21*34125Sbostic.asciz	"@(#)sincos.s	1.1 (Berkeley) 8/21/85; 5.2 (ucb.elefunt) 04/29/88"
2224570Szliu
2324570Szliu#  This is the implementation of Peter Tang's double precision
2424570Szliu#  sine and cosine for the VAX using Bob Corbett's argument reduction.
2524570Szliu#
2624570Szliu#  Notes:
2724570Szliu#       under 1,024,000 random arguments testing on [0,2*pi]
2824570Szliu#       sin() observed maximum error = 0.814 ulps
2924570Szliu#       cos() observed maximum error = 0.792 ulps
3024570Szliu#
3124570Szliu# double sin(arg)
3224570Szliu# double arg;
3324570Szliu# method: true range reduction to [-pi/4,pi/4], P. Tang  &  B. Corbett
3424570Szliu# S. McDonald, April 4,  1985
3524570Szliu#
3624570Szliu	.globl	_sin
3724570Szliu	.text
3824570Szliu	.align	1
3924570Szliu
4024570Szliu_sin:	.word	0xffc		# save r2-r11
4124570Szliu	movq	4(ap),r0
4224570Szliu	bicw3	$0x807f,r0,r2
4324570Szliu	beql	1f		# if x is zero or reserved operand then return x
4424570Szliu#
4524570Szliu# Save the PSL's IV & FU bits on the stack.
4624570Szliu#
4724570Szliu	movpsl	r2
4824570Szliu	bicw3	$0xff9f,r2,-(sp)
4924570Szliu#
5024570Szliu# Clear the IV & FU bits.
5124570Szliu#
5224570Szliu	bicpsw	$0x0060
5324570Szliu#
5424570Szliu#  Entered by  sine    ; save  0  in  r4 .
5524570Szliu#
5624570Szliu	jsb	libm$argred
5724570Szliu	movl	$0,r4
5824570Szliu	jsb	libm$sincos
5924570Szliu	bispsw	(sp)+
6024570Szliu1:	ret
6124570Szliu
6224570Szliu#
6324570Szliu# double cos(arg)
6424570Szliu# double arg;
6524570Szliu# method: true range reduction to [-pi/4,pi/4], P. Tang  &  B. Corbett
6624570Szliu# S. McDonald, April 4,  1985
6724570Szliu#
6824570Szliu	.globl	_cos
6924570Szliu	.text
7024570Szliu	.align	1
7124570Szliu
7224570Szliu_cos:	.word	0xffc		# save r2-r11
7324570Szliu	movq	4(ap),r0
7424570Szliu	bicw3	$0x7f,r0,r2
7524570Szliu	cmpw	$0x8000,r2
7624570Szliu	beql	1f		# if x is reserved operand then return x
7724570Szliu#
7824570Szliu# Save the PSL's IV & FU bits on the stack.
7924570Szliu#
8024570Szliu	movpsl	r2
8124570Szliu	bicw3	$0xff9f,r2,-(sp)
8224570Szliu#
8324570Szliu# Clear the IV & FU bits.
8424570Szliu#
8524570Szliu	bicpsw	$0x0060
8624570Szliu#
8724570Szliu#  Entered by  cosine  ; save  1  in  r4 .
8824570Szliu#
8924570Szliu	jsb	libm$argred
9024570Szliu	movl	$1,r4
9124570Szliu	jsb	libm$sincos
9224570Szliu	bispsw	(sp)+
9324570Szliu1:	ret
94