1/* ix87 specific frexp implementation for float.
2   Copyright (C) 1997, 2000 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(two25,@object)
33two25:	.byte 0, 0, 0, 0x4c
34	ASM_SIZE_DIRECTIVE(two25)
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 VAL	PARMS
44#define EXPP	VAL+4
45
46	.text
47ENTRY (BP_SYM (__frexpf))
48	ENTER
49
50	movl	VAL(%esp), %eax
51	xorl	%ecx, %ecx
52	movl	%eax, %edx
53	andl	$0x7fffffff, %eax
54	jz	1f
55	cmpl	$0x7f800000, %eax
56	jae	1f
57
58	cmpl	$0x00800000, %eax
59	jae	2f
60
61	flds	VAL(%esp)
62#ifdef	PIC
63	call	3f
643:	popl	%edx
65	addl	$_GLOBAL_OFFSET_TABLE_+[.-3b], %edx
66#endif
67	fmuls	MO(two25)
68	movl	$-25, %ecx
69	fstps	VAL(%esp)
70	fwait
71	movl	VAL(%esp), %eax
72	movl	%eax, %edx
73	andl	$0x7fffffff, %eax
74
752:	shrl	$23, %eax
76	andl	$0x807fffff, %edx
77	subl	$126, %eax
78	orl	$0x3f000000, %edx
79	addl	%eax, %ecx
80	movl	%edx, VAL(%esp)
81
82	/* Store %ecx in the variable pointed to by the second argument,
83	   get the factor from the stack and return.  */
841:	movl	EXPP(%esp), %eax
85	CHECK_BOUNDS_BOTH_WIDE (%eax, EXPP(%esp), $4)
86	flds	VAL(%esp)
87	movl	%ecx, (%eax)
88
89	LEAVE
90	ret
91END (BP_SYM (__frexpf))
92weak_alias (BP_SYM (__frexpf), BP_SYM (frexpf))
93