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authorGrazvydas Ignotas <notasas@gmail.com>2017-03-31 01:26:25 +0300
committerMatt Turner <mattst88@gmail.com>2017-04-03 10:52:41 -0700
commita6a38a038bd62e6d9558905f00bef81b5e7e6fcc (patch)
tree31b279352fe710282572467d6900d1041551952f /src/util
parent70c272004f727457e852ba5f2498754b07a7d995 (diff)
util/u_atomic: provide 64bit atomics where they're missing
There are still some distributions trying to support unfortunate people with old or exotic CPUs that don't have 64bit atomic operations. When compiling for such a machine, gcc conveniently inserts a library call to a helper, but it's implementation is missing and we get a linker error. This allows us to provide our own implementation, which is marked weak to prefer a better implementation, should one exist. v2: changed copyright, some style adjustments v3: [mattst88] Print results with AC_MSG_CHECKING/AC_MSG_RESULT Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93089 Signed-off-by: Grazvydas Ignotas <notasas@gmail.com> Reviewed-by: Matt Turner <mattst88@gmail.com>
Diffstat (limited to 'src/util')
-rw-r--r--src/util/Makefile.sources1
-rw-r--r--src/util/u_atomic.c75
2 files changed, 76 insertions, 0 deletions
diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources
index 8ee45d56170..e9057343dc2 100644
--- a/src/util/Makefile.sources
+++ b/src/util/Makefile.sources
@@ -43,6 +43,7 @@ MESA_UTIL_FILES := \
strtod.c \
strtod.h \
texcompress_rgtc_tmp.h \
+ u_atomic.c \
u_atomic.h \
u_endian.h \
u_queue.c \
diff --git a/src/util/u_atomic.c b/src/util/u_atomic.c
new file mode 100644
index 00000000000..44b75fb0c00
--- /dev/null
+++ b/src/util/u_atomic.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright © 2017 Gražvydas Ignotas
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#if defined(MISSING_64BIT_ATOMICS) && defined(HAVE_PTHREAD)
+
+#include <stdint.h>
+#include <pthread.h>
+
+#if defined(HAVE_FUNC_ATTRIBUTE_WEAK) && !defined(__CYGWIN__)
+#define WEAK __attribute__((weak))
+#else
+#define WEAK
+#endif
+
+static pthread_mutex_t sync_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+WEAK uint64_t
+__sync_add_and_fetch_8(uint64_t *ptr, uint64_t val)
+{
+ uint64_t r;
+
+ pthread_mutex_lock(&sync_mutex);
+ *ptr += val;
+ r = *ptr;
+ pthread_mutex_unlock(&sync_mutex);
+
+ return r;
+}
+
+WEAK uint64_t
+__sync_sub_and_fetch_8(uint64_t *ptr, uint64_t val)
+{
+ uint64_t r;
+
+ pthread_mutex_lock(&sync_mutex);
+ *ptr -= val;
+ r = *ptr;
+ pthread_mutex_unlock(&sync_mutex);
+
+ return r;
+}
+
+WEAK uint64_t
+__atomic_fetch_add_8(uint64_t *ptr, uint64_t val, int memorder)
+{
+ return __sync_add_and_fetch(ptr, val);
+}
+
+WEAK uint64_t
+__atomic_fetch_sub_8(uint64_t *ptr, uint64_t val, int memorder)
+{
+ return __sync_sub_and_fetch(ptr, val);
+}
+
+#endif