freebsd-nq/lib/libc/mips/gen/modf.S
Warner Losh d7ee48f115 Bring in initial libc support for mips. These files were taken from
the OpenBSD tree and should be considered preliminary.  They are here
to facilitate building of the tree.
1999-03-03 07:06:17 +00:00

76 lines
2.9 KiB
ArmAsm

/*-
* Copyright (c) 1991, 1993, 1995
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Ralph Campbell.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <machine/asm.h>
#if defined(LIBC_SCCS)
.text
.asciz "$OpenBSD$"
#endif /* LIBC_SCCS */
/*
* double modf(val, iptr)
* double val, *iptr;
* returns: xxx and n (in *iptr) where val == n.xxx
*/
LEAF(modf)
.set reorder
cfc1 t0, $31 # get the control register
li.d $f2, 4503599627370496e0 # f2 <- 2^52
or t1, t0, 0x3 # set rounding mode to round to zero
xor t1, t1, 0x2 # (i.e., 01)
ctc1 t1, $31
mov.d $f0, $f12 # f0 <- f12
abs.d $f4, $f12 # f4 <- |f12|
c.olt.d $f4, $f2 # f4 ? < f2
bc1f 1f # leave f0 alone if Nan, infinity
# or >=2^52
c.eq.d $f12,$f4 # was f12 positive ?
add.d $f4,$f2,$f4 # round off to integer
bc1f 2f # No -> will have to negate result
sub.d $f0,$f4,$f2 # Remove fudge factor
j 1f # integer fraction got
2:
sub.d $f0,$f2,$f4 # Remove fudge factor and negate
1:
ctc1 t0, $31 # restore old rounding mode
s.d $f0, 0(a2) # save the integer part
sub.d $f0, $f12, $f0 # subtract val - integer part
j ra
END(modf)