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/*
* Copyright (c) 1992 Helsinki University of Technology
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* HELSINKI UNIVERSITY OF TECHNOLOGY ALLOWS FREE USE OF THIS SOFTWARE IN
* ITS "AS IS" CONDITION. HELSINKI UNIVERSITY OF TECHNOLOGY DISCLAIMS ANY
* LIABILITY OF ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE
* USE OF THIS SOFTWARE.
*/
#include <machine/asm.h>
#if defined(LIBC_SCCS)
.text
.asciz "$OpenBSD: modf.S,v 1.2 1996/08/19 08:16:50 tholo Exp $"
#endif /* LIBC_SCCS */
ENTRY(modf)
FRAME
movl 8(fp),f0 /* value */
movd 12(fp),r0 /* higher 32 bit of value */
lshd -20,r0 /* extract exponent */
andd 0x7ff,r0 /* 11 lower bits */
cmpd r0,1023+30 /* compare if it's int part can fit in int */
bgt modf_overflow /* nope else it's ok to truncld it to int*/
truncld f0,r0 /* get integer part */
movdl r0,f2 /* convert back to float */
movl f2,0(16(fp)) /* move integer part to *iptr */
subl f2,f0 /* return fract. part = value - *iptr */
EMARF
ret 0
modf_overflow:
subd 1023+20,r0 /* bias 1023, and upper part of
floating point mantissa part */
movqd -1,r2 /* generate mask to get fract. part */
cmpd r0,32 /* if value > 2^52 (20+32) then all int part */
bhi modf_all_ip
negd r0,r0 /* shift right */
lshd r0,r2 /* here */
comd r2,r2 /* get fractional part complement mask */
movd 8(fp),r1 /* get lower 32 bit of value */
andd r2,r1 /* mask fractional part off leave ip part */
movd r1,0(16(fp)) /* store ip part to *iptr */
movd 12(fp),4(16(fp)) /* store other half to *iptr */
subl 0(16(fp)),f0 /* return fract. part = value - *iptr */
EMARF
ret 0
modf_all_ip:
movl 8(fp),0(16(fp)) /* copy value to *iptr */
movdl 0,f0 /* return 0 for fract. part */
EMARF
ret 0
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