76 lines
2.8 KiB
ArmAsm
76 lines
2.8 KiB
ArmAsm
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/* $NetBSD: modf.S,v 1.11 2009/12/14 01:07:42 matt Exp $ */
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/*-
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* Copyright (c) 1991, 1993, 1995
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Ralph Campbell.
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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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#include <mips/asm.h>
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#if defined(LIBC_SCCS) && !defined(lint)
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#if 0
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RCSID("from: @(#)modf.s 8.1 (Berkeley) 6/4/93")
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#else
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RCSID("$NetBSD: modf.S,v 1.11 2009/12/14 01:07:42 matt Exp $")
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#endif
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#endif /* LIBC_SCCS and not lint */
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/*
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* double modf(val, iptr)
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* double val, *iptr;
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* returns: xxx and n (in *iptr) where val == n.xxx
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*/
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LEAF(modf)
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cfc1 t0, $31 # get the control register
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li.d $f2, 4503599627370496e0 # f2 <- 2^52
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or t1, t0, 0x3 # set rounding mode to round to zero
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xor t1, t1, 0x2 # (i.e., 01)
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ctc1 t1, $31
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mov.d $f0, $f12 # f0 <- f12
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abs.d $f4, $f12 # f4 <- |f12|
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c.olt.d $f4, $f2 # f4 ? < f2
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bc1f 1f # leave f0 alone if Nan, infinity
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# or >=2^52
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c.eq.d $f12,$f4 # was f12 positive ?
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add.d $f4,$f2,$f4 # round off to integer
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bc1f 2f # No -> will have to negate result
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sub.d $f0,$f4,$f2 # Remove fudge factor
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j 1f # integer fraction got
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2:
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sub.d $f0,$f2,$f4 # Remove fudge factor and negate
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1:
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ctc1 t0, $31 # restore old rounding mode
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s.d $f0, 0(a2) # save the integer part
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sub.d $f0, $f12, $f0 # subtract val - integer part
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j ra
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END(modf)
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