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Diffstat (limited to 'sysdeps/m68k/fpu/switch/68881-sw.h')
| -rw-r--r-- | sysdeps/m68k/fpu/switch/68881-sw.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/sysdeps/m68k/fpu/switch/68881-sw.h b/sysdeps/m68k/fpu/switch/68881-sw.h new file mode 100644 index 0000000000..3d7a3927f5 --- /dev/null +++ b/sysdeps/m68k/fpu/switch/68881-sw.h @@ -0,0 +1,64 @@ +/* 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 */ |