glibc/sysdeps/m68k/fpu/switch/switch.c
Ulrich Drepper 0c5ecdc449 update from main arhive 970119
Mon Jan 20 03:02:50 1997  Ulrich Drepper  <drepper@cygnus.com>

	* Make-dist: Update and reformat copyright.
	* Makeconfig: Likewise.
	* assert/Makefile: Likewise.
	* bare/Makefile: Likewise.
	* ctype/Makefile: Likewise.
	* dirent/Makefile: Likewise.
	* gmon/Makefile: Likewise.
	* gnulib/Makefile: Likewise.
	* grp/Makefile: Likewise.
	* hurd/Makefile: Likewise.
	* intl/Makefile: Likewise.
	* mach/Makefile: Likewise.
	* malloc/Makefile: Likewise.
	* manual/Makefile: Likewise.
	* math/Makefile: Likewise.
	* po/Makefile: Likewise.
	* pwd/Makefile: Likewise.
	* resource/Makefile: Likewise.
	* setjmp/Makefile: Likewise.
	* socket/Makefile: Likewise.
	* string/Makefile: Likewise.
	* sunrpc/Makefile: Likewise.
	* sysdeps/alpha/Makefile: Likewise.
	* sysdeps/gnu/Makefile: Likewise.
	* sysdeps/m68k/fpu/switch/Makefile: Likewise.
	* sysdeps/m68k/fpu/switch/68881-sw.h: Likewise.
	* sysdeps/m68k/fpu/switch/switch.c: Likewise.
	* sysdeps/mach/Makefile: Likewise.
	* sysdeps/hurd/Makefile: Likewise.
	* sysdeps/sparc/Makefile: Likewise.
	* sysdeps/standalone/i960/nindy960/Makefile: Likewise.
	* sysdeps/standalone/m68k/m68020/mvme136/Makefile: Likewise.
	* sysdeps/unix/common/Makefile: Likewise.
	* sysdeps/unix/sysv/Makefile: Likewise.
	* sysdeps/unix/sysv/irix4/Makefile: Likewise.
	* sysdeps/unix/sysv/sco3.2/Makefile: Likewise.
	* sysdeps/unix/sysv/sysv4/Makefile: Likewise.
	* sysdeps/vax/Makefile: Likewise.
	* sysvipc/Makefile: Likewise.
	* wcsmbs/Makefile: Likewise.
	* wctype/Makefile: Likewise.
	* elf/rtld.c (dl_main): Objects in LD_PRELOAD environment variable
	are separated according to Sun docs by white space not colon.
	* locale/C-time.c (_nl_C_LC_TIME): Use empty string to initialize
	fields which are not defined for the C locale.
	* sysdeps/m68k/fpu/switch/Makefile: Don't use ansidecl.h in constructed
	files.
	* sysdeps/m68k/fpu/switch/68881-sw.h: Likewise.
	* sysdeps/m68k/fpu/switch/switch.c: Likewise.
Sun Jan 19 19:43:31 1997  Andreas Jaeger  <aj@arthur.pfalz.de>
	* time/strptime.c: Provide prototype for strptime_internal.
Sun Jan 19 23:46:27 1997  Ulrich Drepper  <drepper@cygnus.com>
	* glibcbug.in: We don't guarantee confidential handling.  Set
	field to always contain `no'.
Sun Jan 19 21:28:01 1997  Philippe De Muyter  <phdm@info.ucl.ac.be>

	* intl/explodename.c: Include sys/types.h.
	* intl/l10nflist.c: Likewise.

Sat Jan 18 22:15:26 1997  Richard Henderson  <rth@tamu.edu>

	* config.make.in (install_root): New variable to make it easy to
	install glibc somewhere other than /.

	* shlib-versions: alpha-*-linux-* libc=6.1.

	Since sigset_t no longer fits in a register, we can't pass in the
	thread's initial mask so easily.  Take this opportunity to simplify
	the clone implementation by only accepting a single void* argument.

	* sysdeps/unix/sysv/linux/alpha/clone.S: Only take one argument.
	* sysdeps/unix/sysv/linux/i386/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/m68k/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/sparc/clone.S: Likewise.
	* sysdeps/unix/sysv/linux/schedbits.h: Update clone prototypes.

	* sysdeps/unix/sysv/linux/alpha/ioctl-types.h: Remove.
	Default Linux version should be sufficient.

	* sysdeps/unix/sysv/linux/alpha/sigprocmask.c: The osf_sigprocmask
	system call wants the sigset dereferenced.

	* sysdeps/unix/sysv/linux/alpha/syscalls.list: Add entries for
	__syscall_ustat and __syscall_xmknod.
	* sysdeps/unix/sysv/linux/alpha/xmknod.c: Include sys/sysmacros.h.

	* sysdeps/unix/sysv/linux/sigset.h: Use longs instead of ints.

	* sysdeps/unix/sysv/linux/tcsetattr.c: Fix pointer dereferences.

	* sysdeps/unix/sysv/linux/alpha/sigsuspend.c: Add comment about
	dependency to kernel type.

	* sysdeps/unix/sysv/linux/alpha/termbits.h: Correct comment.
1997-01-20 02:49:49 +00:00

88 lines
3.0 KiB
C

/* 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 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., 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;
}