kolibrios-fun/programs/develop/libraries/newlib/math/frexp.S
Sergey Semyonov (Serge) 2336060a0c newlib: update
git-svn-id: svn://kolibrios.org@1906 a494cfbc-eb01-0410-851d-a64ba20cac60
2011-03-11 18:52:24 +00:00

75 lines
1.9 KiB
ArmAsm

/* ix87 specific frexp implementation for double.
Copyright (C) 1997, 2000, 2005 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
.file "frexp.s"
.text
.align 4
two54: .byte 0, 0, 0, 0, 0, 0, 0x50, 0x43
.p2align 4,,15
.globl _frexp
.def _frexp; .scl 2; .type 32; .endef
_frexp:
movl 4(%esp), %ecx
movl 8(%esp), %eax
movl %eax, %edx
andl $0x7fffffff, %eax
orl %eax, %ecx
jz 1f
xorl %ecx, %ecx
cmpl $0x7ff00000, %eax
jae 1f
cmpl $0x00100000, %eax
jae 2f
fld 4(%esp)
fmull two54
movl $-54, %ecx
fstpl 4(%esp)
fwait
movl 8(%esp), %eax
movl %eax, %edx
andl $0x7fffffff, %eax
2:
shrl $20, %eax
andl $0x800fffff, %edx
subl $1022, %eax
orl $0x3fe00000, %edx
addl %eax, %ecx
movl %edx, 8(%esp)
/* Store %ecx in the variable pointed to by the second argument,
get the factor from the stack and return. */
1:
movl 12(%esp), %eax
fldl 4(%esp)
movl %ecx, (%eax)
ret