90 lines
3.0 KiB
ArmAsm
90 lines
3.0 KiB
ArmAsm
/* $NetBSD: n_tan.S,v 1.6 2003/08/07 16:44:45 agc Exp $ */
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/*
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* Copyright (c) 1985, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)tan.s 8.1 (Berkeley) 6/4/93
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*/
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#include <machine/asm.h>
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/* This is the implementation of Peter Tang's double precision
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* tangent for the VAX using Bob Corbett's argument reduction.
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*
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* Notes:
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* under 1,024,000 random arguments testing on [0,2*pi]
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* tan() observed maximum error = 2.15 ulps
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*
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* double tan(arg)
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* double arg;
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* method: true range reduction to [-pi/4,pi/4], P. Tang & B. Corbett
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* S. McDonald, April 4, 1985
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*/
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ENTRY(tan, 0x0fc0) # save %r6-%r11
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movq 4(%ap),%r0
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bicw3 $0x807f,%r0,%r2
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beql 1f # if x is zero or reserved operand then return x
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/*
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* Save the PSL's IV & FU bits on the stack.
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*/
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movpsl %r2
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bicw3 $0xff9f,%r2,-(%sp)
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/*
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* Clear the IV & FU bits.
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*/
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bicpsw $0x0060
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jsb _C_LABEL(__libm_argred)+2
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/*
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* At this point,
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* %r0 contains the quadrant number, 0, 1, 2, or 3;
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* %r2/%r1 contains the reduced argument as a D-format number;
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* %r3 contains a F-format extension to the reduced argument;
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*
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* Save %r3/%r0 so that we can call cosine after calling sine.
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*/
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movq %r2,-(%sp)
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movq %r0,-(%sp)
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/*
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* Call sine. %r4 = 0 implies sine.
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*/
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movl $0,%r4
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jsb _C_LABEL(__libm_sincos)+2
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/*
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* Save sin(x) in %r11/%r10 .
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*/
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movd %r0,%r10
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/*
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* Call cosine. %r4 = 1 implies cosine.
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*/
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movq (%sp)+,%r0
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movq (%sp)+,%r2
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movl $1,%r4
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jsb _C_LABEL(__libm_sincos)+2
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divd3 %r0,%r10,%r0
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bispsw (%sp)+
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1: ret
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