don't copyright the sed script
[unix-history] / usr / src / lib / libm / vax / sincos.s
# Copyright (c) 1985 Regents of the University of California.
# All rights reserved.
#
# %sccs.include.redist.sh%
#
# @(#)sincos.s 5.4 (Berkeley) %G%
#
.data
.align 2
_sccsid:
.asciz "@(#)sincos.s 1.1 (Berkeley) 8/21/85; 5.4 (ucb.elefunt) %G%"
# 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