# # 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) 08/21/85 # 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