1 files changed, 93 insertions, 0 deletions
diff --git a/linuxthreads/sysdeps/i386/pt-machine.h b/linuxthreads/sysdeps/i386/pt-machine.h
new file mode 100644
index 0000000000..ef4df2a1a3
--- /dev/null
+++ b/linuxthreads/sysdeps/i386/pt-machine.h
@@ -0,0 +1,93 @@
+/* Machine-dependent pthreads configuration and inline functions.
+   i386 version.
+   Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Richard Henderson <rth@tamu.edu>.
+
+   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.  */
+
+
+/* Spinlock implementation; required.  */
+extern inline int
+testandset (int *spinlock)
+{
+  int ret;
+
+  __asm__ __volatile__("xchgl %0, %1"
+	: "=r"(ret), "=m"(*spinlock)
+	: "0"(1), "m"(*spinlock));
+
+  return ret;
+}
+
+
+/* Get some notion of the current stack.  Need not be exactly the top
+   of the stack, just something somewhere in the current frame.  */
+#define CURRENT_STACK_FRAME  stack_pointer
+register char * stack_pointer __asm__ ("%esp");
+
+
+/* Compare-and-swap for semaphores.
+   Available on the 486 and above, but not on the 386.
+   We test dynamically whether it's available or not. */
+
+#define HAS_COMPARE_AND_SWAP
+#define TEST_FOR_COMPARE_AND_SWAP
+
+extern inline int
+__compare_and_swap (long int *p, long int oldval, long int newval)
+{
+  char ret;
+  long int readval;
+
+  __asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0"
+			: "=q" (ret), "=m" (*p), "=a" (readval)
+			: "r" (newval), "m" (*p), "a" (oldval));
+  return ret;
+}
+
+
+extern inline int
+get_eflags (void)
+{
+  int res;
+  __asm__ __volatile__ ("pushfl; popl %0" : "=r" (res) : );
+  return res;
+}
+
+
+extern inline void
+set_eflags (int newflags)
+{
+  __asm__ __volatile__ ("pushl %0; popfl" : : "r" (newflags) : "cc");
+}
+
+
+extern inline int
+compare_and_swap_is_available (void)
+{
+  int oldflags = get_eflags ();
+  int changed;
+  /* Flip AC bit in EFLAGS.  */
+  set_eflags (oldflags ^ 0x40000);
+  /* See if bit changed.  */
+  changed = (get_eflags () ^ oldflags) & 0x40000;
+  /* Restore EFLAGS.  */
+  set_eflags (oldflags);
+  /* If the AC flag did not change, it's a 386 and it lacks cmpxchg.
+     Otherwise, it's a 486 or above and it has cmpxchg.  */
+  return changed != 0;
+}