glibc/sysdeps/libm-i387/s_frexp.S

83 lines
2.0 KiB
ArmAsm

/* ix87 specific frexp implementation for double.
Copyright (C) 1997 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <machine/asm.h>
#ifdef __ELF__
.section .rodata
#else
.text
#endif
.align ALIGNARG(4)
ASM_TYPE_DIRECTIVE(two54,@object)
two54: .byte 0, 0, 0, 0, 0, 0, 0x50, 0x43
ASM_SIZE_DIRECTIVE(two54)
#ifdef PIC
#define MO(op) op##@GOTOFF(%edx)
#else
#define MO(op) op
#endif
.text
ENTRY(__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
fldl 4(%esp)
#ifdef PIC
call 3f
3: popl %edx
addl $_GLOBAL_OFFSET_TABLE_+[.-3b], %edx
#endif
fmull MO(two54)
movl $-54, %ecx
fstpl 4(%esp)
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
END(__frexp)
weak_alias (__frexp, frexp)