4.4BSD/usr/src/old/libm/libm/VAX/sincos.s

# 
# Copyright (c) 1985 Regents of the University of California.
# 
# Use and reproduction of this software are granted  in  accordance  with
# the terms and conditions specified in  the  Berkeley  Software  License
# Agreement (in particular, this entails acknowledgement of the programs'
# source, and inclusion of this notice) with the additional understanding
# that  all  recipients  should regard themselves as participants  in  an
# ongoing  research  project and hence should  feel  obligated  to report
# their  experiences (good or bad) with these elementary function  codes,
# using "sendbug 4bsd-bugs@BERKELEY", to the authors.
#

# @(#)sincos.s	1.1 (Berkeley) 8/21/85

#  This is the implementation of Peter Tang's double precision  
#  sine and cosine for the VAX using Bob Corbett's argument reduction.
#  
#  Notes:
#       under 1,024,000 random arguments testing on [0,2*pi] 
#       sin() observed maximum error = 0.814 ulps
#       cos() observed maximum error = 0.792 ulps
#
# double sin(arg)
# double arg;
# method: true range reduction to [-pi/4,pi/4], P. Tang  &  B. Corbett
# S. McDonald, April 4,  1985
#
	.globl	_sin
	.text
	.align	1

_sin:	.word	0xffc		# save r2-r11
	movq	4(ap),r0
	bicw3	$0x807f,r0,r2
	beql	1f		# if x is zero or reserved operand then return x
#
# Save the PSL's IV & FU bits on the stack.
#
	movpsl	r2
	bicw3	$0xff9f,r2,-(sp)
#
# Clear the IV & FU bits.
#
	bicpsw	$0x0060
#
#  Entered by  sine    ; save  0  in  r4 .
#
	jsb	libm$argred
	movl	$0,r4
	jsb	libm$sincos
	bispsw	(sp)+
1:	ret

#
# double cos(arg)
# double arg;
# method: true range reduction to [-pi/4,pi/4], P. Tang  &  B. Corbett
# S. McDonald, April 4,  1985
#
	.globl	_cos
	.text
	.align	1

_cos:	.word	0xffc		# save r2-r11
	movq	4(ap),r0
	bicw3	$0x7f,r0,r2
	cmpw	$0x8000,r2
	beql	1f		# if x is reserved operand then return x
#
# Save the PSL's IV & FU bits on the stack.
#
	movpsl	r2
	bicw3	$0xff9f,r2,-(sp)
#
# Clear the IV & FU bits.
#
	bicpsw	$0x0060
#
#  Entered by  cosine  ; save  1  in  r4 .
#
	jsb	libm$argred
	movl	$1,r4
	jsb	libm$sincos
	bispsw	(sp)+
1:	ret