summary refs log tree commit diff
path: root/sysdeps/m68k/fpu/switch/68881-sw.h
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/m68k/fpu/switch/68881-sw.h')
-rw-r--r--sysdeps/m68k/fpu/switch/68881-sw.h64
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  */