Merged eb/gcell-wip2 rev 10130:10152 into trunk.

[debian/gnuradio] / gcell / ibm / sync / ppu_source / atomic_dec_if_positive.h

diff --git a/gcell/ibm/sync/ppu_source/atomic_dec_if_positive.h b/gcell/ibm/sync/ppu_source/atomic_dec_if_positive.h
new file mode 100644 (file)
index 0000000..c4d113b
--- /dev/null
+++ b/gcell/ibm/sync/ppu_source/atomic_dec_if_positive.h
@@ -0,0 +1,76 @@
+/* --------------------------------------------------------------  */
+/* (C)Copyright 2001,2007,                                         */
+/* International Business Machines Corporation,                    */
+/* Sony Computer Entertainment, Incorporated,                      */
+/* Toshiba Corporation,                                            */
+/*                                                                 */
+/* All Rights Reserved.                                            */
+/*                                                                 */
+/* Redistribution and use in source and binary forms, with or      */
+/* without modification, are permitted provided that the           */
+/* following conditions are met:                                   */
+/*                                                                 */
+/* - Redistributions of source code must retain the above copyright*/
+/*   notice, this list of conditions and the following disclaimer. */
+/*                                                                 */
+/* - Redistributions in binary form must reproduce the above       */
+/*   copyright notice, this list of conditions and the following   */
+/*   disclaimer in the documentation and/or other materials        */
+/*   provided with the distribution.                               */
+/*                                                                 */
+/* - Neither the name of IBM Corporation nor the names of its      */
+/*   contributors may be used to endorse or promote products       */
+/*   derived from this software without specific prior written     */
+/*   permission.                                                   */
+/*                                                                 */
+/* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND          */
+/* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,     */
+/* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF        */
+/* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE        */
+/* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR            */
+/* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,    */
+/* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT    */
+/* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;    */
+/* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)        */
+/* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN       */
+/* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR    */
+/* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,  */
+/* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.              */
+/* --------------------------------------------------------------  */
+/* PROLOG END TAG zYx                                              */
+#ifndef _PPU_ATOMIC_DEC_IF_POSITIVE_H_
+#define _PPU_ATOMIC_DEC_IF_POSITIVE_H_
+
+#include <ppu_intrinsics.h>
+#include "sync_utils.h"
+#include "atomic.h"
+
+/*
+ * atomic_dec_if_positive - atomically decrement if counter is positive.
+ *
+ *  v: handle to effective address of counter.
+ * 
+ * Atomically decrement a counter if its value is positive.
+ * The only restriction is that v must be word aligned.
+ *
+ *
+ * Returns the old value of the counter, minus 1.
+ */
+static __inline int _atomic_dec_if_positive(atomic_ea_t v)
+{
+  int ret;
+  int tmp;
+  void *p;
+
+  SYNC_ULL_TO_PTR(v, p);
+
+  do {
+    tmp = (int)__lwarx(p);
+    ret = tmp - 1;
+    tmp = (tmp > 0) ? ret : tmp; 
+  } while (__stwcx(p, (unsigned)tmp) == 0);
+
+  return ret;
+}
+
+#endif /* _PPU_ATOMIC_DEC_IF_POSITIVE_H_ */