1/* ix87 specific frexp implementation for long double.
2   Copyright (C) 1997, 2000, 2001 Free Software Foundation, Inc.
3   This file is part of the GNU C Library.
4   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
5
6   The GNU C Library is free software; you can redistribute it and/or
7   modify it under the terms of the GNU Lesser General Public
8   License as published by the Free Software Foundation; either
9   version 2.1 of the License, or (at your option) any later version.
10
11   The GNU C Library is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14   Lesser General Public License for more details.
15
16   You should have received a copy of the GNU Lesser General Public
17   License along with the GNU C Library; if not, write to the Free
18   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19   02111-1307 USA.  */
20
21#include <machine/asm.h>
22#include "bp-sym.h"
23#include "bp-asm.h"
24
25#ifdef __ELF__
26	.section .rodata
27#else
28	.text
29#endif
30
31	.align ALIGNARG(4)
32	ASM_TYPE_DIRECTIVE(two64,@object)
33two64:	.byte 0, 0, 0, 0, 0, 0, 0xf0, 0x43
34	ASM_SIZE_DIRECTIVE(two64)
35
36#ifdef PIC
37#define MO(op) op##@GOTOFF(%edx)
38#else
39#define MO(op) op
40#endif
41
42#define PARMS	LINKAGE		/* no space for saved regs */
43#define VAL0	PARMS
44#define VAL1	VAL0+4
45#define VAL2	VAL1+4
46#define EXPP	VAL2+4
47
48	.text
49ENTRY (BP_SYM (__frexpl))
50	ENTER
51
52	movl	VAL0(%esp), %ecx
53	movl	VAL2(%esp), %eax
54	orl	VAL1(%esp), %ecx
55	movl	%eax, %edx
56	andl	$0x7fff, %eax
57	orl	%eax, %ecx
58	jz	1f
59	xorl	%ecx, %ecx
60	cmpl	$0x7fff, %eax
61	je	1f
62
63	cmpl	$0, %eax
64	jne	2f
65
66	fldt	VAL0(%esp)
67#ifdef	PIC
68	call	3f
693:	popl	%edx
70	addl	$_GLOBAL_OFFSET_TABLE_+[.-3b], %edx
71#endif
72
73	fmull	MO(two64)	/* It's not necessary to use a 80bit factor */
74	movl	$-64, %ecx
75	fstpt	VAL0(%esp)
76	fwait
77	movl	VAL2(%esp), %eax
78	movl	%eax, %edx
79	andl	$0x7fff, %eax
80
812:	andl	$0x8000, %edx
82	subl	$16382, %eax
83	orl	$0x3ffe, %edx
84	addl	%eax, %ecx
85	movl	%edx, VAL2(%esp)
86
87	/* Store %ecx in the variable pointed to by the second argument,
88	   get the factor from the stack and return.  */
891:	movl	EXPP(%esp), %eax
90	CHECK_BOUNDS_BOTH_WIDE (%eax, EXPP(%esp), $4)
91	fldt	VAL0(%esp)
92	movl	%ecx, (%eax)
93
94	LEAVE
95	ret
96END (BP_SYM (__frexpl))
97weak_alias (BP_SYM (__frexpl), BP_SYM (frexpl))
98