1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
|
/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#ifndef _68881_SWITCH_H
#define _68881_SWITCH_H 1
#include <sys/cdefs.h>
/* This is the format of the data at the code label for a function which
wants to switch depending on whether or not a 68881 is present.
Initially, `insn' is a `jsr' instruction, and `target' is __68881_switch.
The first time such a function is called, __68881_switch determines whether
or not a 68881 is present, and modifies the function accordingly.
Then `insn' is a `jmp' instruction, and `target' is the value of `fpu'
if there is 68881, or the value of `soft' if not. */
struct switch_caller
{
unsigned short int insn; /* The `jsr' or `jmp' instruction. */
__ptr_t target; /* The target of the instruction. */
__ptr_t soft; /* The address of the soft function. */
__ptr_t fpu; /* The address of the 68881 function. */
};
/* These are opcodes (values for `insn', above) for `jmp' and `jsr'
instructions, respectively, to 32-bit absolute addresses. */
#define JMP 0x4ef9
#define JSR 0x4eb9
/* Function to determine whether or not a 68881 is available,
and modify its caller (which must be a `struct switch_caller', above,
in data space) to use the appropriate version. */
extern void EXFUN(__68881_switch, (int __dummy));
/* Define FUNCTION as a `struct switch_caller' which will call
`__FUNCTION_68881' if a 68881 is present, and `__FUNCTION_soft' if not.
#define switching_function(FUNCTION) \
struct switch_caller FUNCTION = \
{ \
JSR, (__ptr_t) __68881_switch, \
__CONCAT(__CONCAT(__,FUNCTION),_soft), \
__CONCAT(__CONCAT(__,FUNCTION),_68881) \
}
#endif /* 68881-switch.h */
|
