94 lines
3.2 KiB
ArmAsm
94 lines
3.2 KiB
ArmAsm
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/*
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* Copyright (c) 1983, 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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#if defined(LIBC_SCCS) && !defined(lint)
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/*.asciz "@(#)ldexp.s 8.1 (Berkeley) 6/4/93" */
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.asciz "$NetBSD: ldexp.S,v 1.6 2003/08/07 16:42:31 agc Exp $"
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#endif /* LIBC_SCCS and not lint */
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/*
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* double ldexp (value, exp)
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* double value;
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* int exp;
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*
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* Ldexp returns value*2**exp, if that result is in range.
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* If underflow occurs, it returns zero. If overflow occurs,
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* it returns a value of appropriate sign and largest
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* possible magnitude. In case of either overflow or underflow,
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* errno is set to ERANGE. Note that errno is not modified if
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* no error occurs.
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*/
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#include "DEFS.h"
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/*
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* don't include errno.h, ANSI C says it defines errno.
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*
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* #include <errno.h>
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*/
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#define ERANGE 34
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.globl _C_LABEL(errno)
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ENTRY(ldexp, 0)
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movd 4(%ap),%r0 /* fetch "value" */
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extzv $7,$8,%r0,%r2 /* %r2 := biased exponent */
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jeql 1f /* if zero, done */
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addl2 12(%ap),%r2 /* %r2 := new biased exponent */
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jleq 2f /* if <= 0, underflow */
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cmpl %r2,$256 /* otherwise check if too big */
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jgeq 3f /* jump if overflow */
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insv %r2,$7,$8,%r0 /* put exponent back in result */
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1:
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ret
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2:
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clrd %r0
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jbr 1f
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3:
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movd huge,%r0 /* largest possible floating magnitude */
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jbc $15,4(%ap),1f /* jump if argument was positive */
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mnegd %r0,%r0 /* if arg < 0, make result negative */
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1:
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#ifdef _REENTRANT
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pushl %r0
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calls $0,_C_LABEL(__errno)
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movl $ ERANGE,(%r0)
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movl (%sp)+,%r0
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#else
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movl $ ERANGE,_C_LABEL(errno)
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#endif
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ret
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.data
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huge: .word 0x7fff /* the largest number that can */
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.word 0xffff /* be represented in a long floating */
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.word 0xffff /* number. This is given in hex in order */
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.word 0xffff /* to avoid floating conversions */
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