diff options
Diffstat (limited to 'sysdeps/m68k/fpu/switch/switch.c')
| -rw-r--r-- | sysdeps/m68k/fpu/switch/switch.c | 87 |
1 files changed, 0 insertions, 87 deletions
diff --git a/sysdeps/m68k/fpu/switch/switch.c b/sysdeps/m68k/fpu/switch/switch.c deleted file mode 100644 index e0558176dc..0000000000 --- a/sysdeps/m68k/fpu/switch/switch.c +++ /dev/null @@ -1,87 +0,0 @@ -/* 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; -} |