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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..c5a0f71fa6 --- /dev/null +++ b/sysdeps/m68k/fpu/switch/68881-sw.h @@ -0,0 +1,64 @@ +/* Copyright (C) 1991, 1992, 1997, 2000 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 Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 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. */ + void *target; /* The target of the instruction. */ + void *soft; /* The address of the soft function. */ + void *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 __68881_switch (int __dummy) __THROW; + + +/* 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 */ |