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[PATCH] fix parisc atomic locking builtins for libgomp
- From: Helge Deller <deller at gmx dot de>
- To: gcc-patches at gcc dot gnu dot org
- Cc: John David Anglin <dave at hiauly1 dot hia dot nrc dot ca>, Carlos O'Donell <carlos at systemhalted dot org>
- Date: Sun, 23 Nov 2008 21:57:54 +0100
- Subject: [PATCH] fix parisc atomic locking builtins for libgomp
The attached patch fixes gcc's atomic locking builtins on parisc so that
they can be used for libgomp with HAVE_SYNC_BUILTINS defined.
Successfully tested with the libgomp testsuite.
2008-11-23 Helge Deller <deller@gmx.de>
* pa/linux-atomic.c (EBUSY): Define if not _LP64.
(__kernel_cmpxchg): Return -EBUSY if the kernel LWS call
succeeded and lws_ret is not equal to oldval.
Index: config/pa/linux-atomic.c
===================================================================
--- config/pa/linux-atomic.c (revision 142140)
+++ config/pa/linux-atomic.c (working copy)
@@ -33,8 +33,9 @@
#ifndef _LP64
#include <errno.h>
#else
+#define EFAULT 14
+#define EBUSY 16
#define ENOSYS 251
-#define EFAULT 14
#endif
/* All PA-RISC implementations supported by linux have strongly
@@ -74,6 +75,13 @@
);
if (__builtin_expect (lws_errno == -EFAULT || lws_errno == -ENOSYS, 0))
ABORT_INSTRUCTION;
+
+ /* If the kernel LWS call succeeded (lws_errno == 0), lws_ret contains
+ the old value from memory. If this value is equal to OLDVAL, the
+ new value was written to memory. If not, return -EBUSY. */
+ if (!lws_errno && lws_ret != oldval)
+ lws_errno = -EBUSY;
+
return lws_errno;
}