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-rw-r--r--sysdeps/m68k/m680x0/fpu/switch/68881-sw.h64
-rw-r--r--sysdeps/m68k/m680x0/fpu/switch/Makefile51
-rw-r--r--sysdeps/m68k/m680x0/fpu/switch/bits/mathinline.h1
-rw-r--r--sysdeps/m68k/m680x0/fpu/switch/switch.c87
4 files changed, 203 insertions, 0 deletions
diff --git a/sysdeps/m68k/m680x0/fpu/switch/68881-sw.h b/sysdeps/m68k/m680x0/fpu/switch/68881-sw.h
new file mode 100644
index 0000000000..c5a0f71fa6
--- /dev/null
+++ b/sysdeps/m68k/m680x0/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 */
diff --git a/sysdeps/m68k/m680x0/fpu/switch/Makefile b/sysdeps/m68k/m680x0/fpu/switch/Makefile
new file mode 100644
index 0000000000..c04107163c
--- /dev/null
+++ b/sysdeps/m68k/m680x0/fpu/switch/Makefile
@@ -0,0 +1,51 @@
+# Copyright (C) 1991, 1992, 1997 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.
+
+ifeq ($(subdir),math)
+
+sysdep_routines := $(sysdep_routines) switch
+
+# Find all the sources that have 68881 versions.
++68881-sources := \
+ $(notdir $(wildcard $(addprefix $(filter %/fpu,$(sysdirs)),$(sources))))
+
+# Sysdep directories other than fpu and fpu/switch (this one).
++non68881-dirs := $(filter-out %/fpu %/fpu/switch,$(+sysdep_dirs))
+
+# Get a non-68881 version of the target.
++non68881-version = $(firstword $(wildcard $(addsuffix /$@,$(+non68881-dirs))))
+
+# Directory containing 68881 sources.
++68881-dir := $(filter %/fpu,$(+sysdep_dirs))
+
+# For all the files that have 68881 versions and don't exist already in
+# the source directory (math), automatically make ones that switch between
+# 68881 and soft versions.
+$(addprefix $(objpfx), \
+ $(filter-out $(wildcard $(+68881-sources)),$(+68881-sources))):
+ (echo '#include <68881-sw.h>' ;\
+ echo '#define $* __$*_68881' ;\
+ echo '#include <$(+68881-dir)/$@>' ;\
+ echo '#undef $*' ;\
+ echo '#define $* __$*_soft' ;\
+ echo '#include <$(non68881-version)>' ;\
+ echo '#undef $*' ;\
+ echo 'switching_function($*);') > $@-tmp
+ mv $@-tmp $@
+
+endif
diff --git a/sysdeps/m68k/m680x0/fpu/switch/bits/mathinline.h b/sysdeps/m68k/m680x0/fpu/switch/bits/mathinline.h
new file mode 100644
index 0000000000..c0f6966981
--- /dev/null
+++ b/sysdeps/m68k/m680x0/fpu/switch/bits/mathinline.h
@@ -0,0 +1 @@
+/* We don't want any inlines when we might not have a 68881. */
diff --git a/sysdeps/m68k/m680x0/fpu/switch/switch.c b/sysdeps/m68k/m680x0/fpu/switch/switch.c
new file mode 100644
index 0000000000..e0558176dc
--- /dev/null
+++ b/sysdeps/m68k/m680x0/fpu/switch/switch.c
@@ -0,0 +1,87 @@
+/* Copyright (C) 1991, 1992, 1997 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. */
+
+#include <signal.h>
+#include <68881-sw.h>
+
+
+/* The signal that is sent when a 68881 instruction
+ is executed and there is no 68881. */
+#ifndef TRAPSIG
+#define TRAPSIG SIGILL
+#endif
+
+/* Zero if no 68881, one if we have a 68881, or -1 if we don't know yet. */
+static int have_fpu = -1;
+
+
+/* Signal handler for the trap that happens if we don't have a 68881. */
+static void
+trap (sig)
+ int sig;
+{
+ have_fpu = 0;
+}
+
+/* This function is called by functions that want to switch.
+ The calling function must be a `struct switch_caller' in data space.
+ It determines whether a 68881 is present, and modifies its caller
+ to be a static jump to either the 68881 version or the soft version.
+ It then returns into the function it has chosen to do the work. */
+void
+__68881_switch (dummy)
+ int dummy;
+{
+ void **return_address_location = &((void **) &dummy)[-1];
+ struct switch_caller *const caller
+ = (struct switch_caller *) (((short int *) *return_address_location) - 1);
+
+ if (have_fpu < 0)
+ {
+ /* Figure out whether or not we have a 68881. */
+ __sighandler_t handler = signal (TRAPSIG, trap);
+ if (handler == SIG_ERR)
+ /* We can't figure it out, so assume we don't have a 68881.
+ This assumption will never cause us any problems other than
+ lost performance, while the reverse assumption could cause
+ the program to crash. */
+ have_fpu = 0;
+ else
+ {
+ /* We set `have_fpu' to nonzero, and then execute a 68881
+ no-op instruction. If we have a 68881, this will do nothing.
+ If we don't have one, this will trap and the signal handler
+ will clear `have_fpu'. */
+ have_fpu = 1;
+ asm ("fnop");
+
+ /* Restore the old signal handler. */
+ (void) signal (TRAPSIG, handler);
+ }
+ }
+
+ /* Modify the caller to be a jump to the appropriate address. */
+ caller->insn = JMP;
+ caller->target = have_fpu ? caller->fpu : caller->soft;
+
+ /* Make the address we will return to be the target we have chosen.
+ Our return will match the `jsr' done by the caller we have
+ just modified, and it will be just as if that had instead
+ been a `jmp' to the new target. */
+ *return_address_location = caller->target;
+}