summaryrefslogtreecommitdiff
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..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 */