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-rw-r--r--gcc-4.4.0/libgomp/config/linux/ptrlock.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/gcc-4.4.0/libgomp/config/linux/ptrlock.c b/gcc-4.4.0/libgomp/config/linux/ptrlock.c
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+++ b/gcc-4.4.0/libgomp/config/linux/ptrlock.c
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+/* Copyright (C) 2008, 2009 Free Software Foundation, Inc.
+ Contributed by Jakub Jelinek <jakub@redhat.com>.
+
+ This file is part of the GNU OpenMP Library (libgomp).
+
+ Libgomp is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3, or (at your option)
+ any later version.
+
+ Libgomp 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 General Public License for
+ more details.
+
+ Under Section 7 of GPL version 3, you are granted additional
+ permissions described in the GCC Runtime Library Exception, version
+ 3.1, as published by the Free Software Foundation.
+
+ You should have received a copy of the GNU General Public License and
+ a copy of the GCC Runtime Library Exception along with this program;
+ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+ <http://www.gnu.org/licenses/>. */
+
+/* This is a Linux specific implementation of a mutex synchronization
+ mechanism for libgomp. This type is private to the library. This
+ implementation uses atomic instructions and the futex syscall. */
+
+#include <endian.h>
+#include <limits.h>
+#include "wait.h"
+
+void *
+gomp_ptrlock_get_slow (gomp_ptrlock_t *ptrlock)
+{
+ int *intptr;
+ __sync_bool_compare_and_swap (ptrlock, 1, 2);
+
+ /* futex works on ints, not pointers.
+ But a valid work share pointer will be at least
+ 8 byte aligned, so it is safe to assume the low
+ 32-bits of the pointer won't contain values 1 or 2. */
+ __asm volatile ("" : "=r" (intptr) : "0" (ptrlock));
+#if __BYTE_ORDER == __BIG_ENDIAN
+ if (sizeof (*ptrlock) > sizeof (int))
+ intptr += (sizeof (*ptrlock) / sizeof (int)) - 1;
+#endif
+ do
+ do_wait (intptr, 2);
+ while (*intptr == 2);
+ __asm volatile ("" : : : "memory");
+ return *ptrlock;
+}
+
+void
+gomp_ptrlock_set_slow (gomp_ptrlock_t *ptrlock, void *ptr)
+{
+ int *intptr;
+
+ *ptrlock = ptr;
+ __asm volatile ("" : "=r" (intptr) : "0" (ptrlock));
+#if __BYTE_ORDER == __BIG_ENDIAN
+ if (sizeof (*ptrlock) > sizeof (int))
+ intptr += (sizeof (*ptrlock) / sizeof (int)) - 1;
+#endif
+ futex_wake (intptr, INT_MAX);
+}