re PR target/65697 (__atomic memory barriers not strong enough for __sync builtins)

2015-05-12  Andrew MacLeod  <amacleod@redhat.com>

	PR target/65697
	* coretypes.h (MEMMODEL_SYNC, MEMMODEL_BASE_MASK): New macros.
	(enum memmodel): Add SYNC_{ACQUIRE,RELEASE,SEQ_CST}.
	* tree.h (memmodel_from_int, memmodel_base, is_mm_relaxed,
	is_mm_consume,is_mm_acquire, is_mm_release, is_mm_acq_rel,
	is_mm_seq_cst, is_mm_sync): New accessor functions.
	* builtins.c (expand_builtin_sync_operation,
	expand_builtin_compare_and_swap): Use MEMMODEL_SYNC_SEQ_CST.
	(expand_builtin_sync_lock_release): Use MEMMODEL_SYNC_RELEASE.
	(get_memmodel,  expand_builtin_atomic_compare_exchange,
	expand_builtin_atomic_load, expand_builtin_atomic_store,
	expand_builtin_atomic_clear): Use new accessor routines.
	(expand_builtin_sync_synchronize): Use MEMMODEL_SYNC_SEQ_CST.
	* optabs.c (expand_compare_and_swap_loop): Use MEMMODEL_SYNC_SEQ_CST.
	(maybe_emit_sync_lock_test_and_set): Use new accessors and
	MEMMODEL_SYNC_ACQUIRE.
	(expand_sync_lock_test_and_set): Use MEMMODEL_SYNC_ACQUIRE.
	(expand_mem_thread_fence, expand_mem_signal_fence, expand_atomic_load,
	expand_atomic_store): Use new accessors.
	* emit-rtl.c (need_atomic_barrier_p): Add additional enum cases.
	* tsan.c (instrument_builtin_call): Update check for memory model beyond
	final enum to use MEMMODEL_LAST.
	* c-family/c-common.c: Use new accessor for memmodel_base.
	* config/aarch64/aarch64.c (aarch64_expand_compare_and_swap): Use new
	accessors.
	* config/aarch64/atomics.md (atomic_load<mode>,atomic_store<mode>,
	arch64_load_exclusive<mode>, aarch64_store_exclusive<mode>,
	mem_thread_fence, *dmb): Likewise.
	* config/alpha/alpha.c (alpha_split_compare_and_swap,
	alpha_split_compare_and_swap_12): Likewise.
	* config/arm/arm.c (arm_expand_compare_and_swap,
	arm_split_compare_and_swap, arm_split_atomic_op): Likewise.
	* config/arm/sync.md (atomic_load<mode>, atomic_store<mode>,
	atomic_loaddi): Likewise.
	* config/i386/i386.c (ix86_destroy_cost_data, ix86_memmodel_check):
	Likewise.
	* config/i386/sync.md (mem_thread_fence, atomic_store<mode>): Likewise.
	* config/ia64/ia64.c (ia64_expand_atomic_op): Add new memmodel cases and
	use new accessors.
	* config/ia64/sync.md (mem_thread_fence, atomic_load<mode>,
	atomic_store<mode>, atomic_compare_and_swap<mode>,
	atomic_exchange<mode>): Use new accessors.
	* config/mips/mips.c (mips_process_sync_loop): Likewise.
	* config/pa/pa.md (atomic_loaddi, atomic_storedi): Likewise.
	* config/rs6000/rs6000.c (rs6000_pre_atomic_barrier,
	rs6000_post_atomic_barrier): Add new cases.
	(rs6000_expand_atomic_compare_and_swap): Use new accessors.
	* config/rs6000/sync.md (mem_thread_fence): Add new cases.
	(atomic_load<mode>): Add new cases and use new accessors.
	(store_quadpti): Add new cases.
	* config/s390/s390.md (mem_thread_fence, atomic_store<mode>): Use new
	accessors.
	* config/sparc/sparc.c (sparc_emit_membar_for_model): Use new accessors.
	* doc/extend.texi: Update docs to indicate 16 bits are used for memory
	model, not 8.

From-SVN: r223096

1 files changed, 16 insertions, 4 deletions

diff --git a/gcc/coretypes.h b/gcc/coretypes.h
index 90fa13faf3b..0ee8633c727 100644
--- a/gcc/coretypes.h
+++ b/gcc/coretypes.h
@@ -263,6 +263,18 @@ enum function_class {
   function_c11_misc
 };
 
+/* Suppose that higher bits are target dependent. */
+#define MEMMODEL_MASK ((1<<16)-1)
+
+/* Legacy sync operations set this upper flag in the memory model.  This allows
+   targets that need to do something stronger for sync operations to
+   differentiate with their target patterns and issue a more appropriate insn
+   sequence.  See bugzilla 65697 for background.  */
+#define MEMMODEL_SYNC (1<<15)
+
+/* Memory model without SYNC bit for targets/operations that do not care.  */
+#define MEMMODEL_BASE_MASK (MEMMODEL_SYNC-1)
+
 /* Memory model types for the __atomic* builtins. 
    This must match the order in libstdc++-v3/include/bits/atomic_base.h.  */
 enum memmodel
@@ -273,12 +285,12 @@ enum memmodel
   MEMMODEL_RELEASE = 3,
   MEMMODEL_ACQ_REL = 4,
   MEMMODEL_SEQ_CST = 5,
-  MEMMODEL_LAST = 6
+  MEMMODEL_LAST = 6,
+  MEMMODEL_SYNC_ACQUIRE = MEMMODEL_ACQUIRE | MEMMODEL_SYNC,
+  MEMMODEL_SYNC_RELEASE = MEMMODEL_RELEASE | MEMMODEL_SYNC,
+  MEMMODEL_SYNC_SEQ_CST = MEMMODEL_SEQ_CST | MEMMODEL_SYNC
 };
 
-/* Suppose that higher bits are target dependent. */
-#define MEMMODEL_MASK ((1<<16)-1)
-
 /* Support for user-provided GGC and PCH markers.  The first parameter
    is a pointer to a pointer, the second a cookie.  */
 typedef void (*gt_pointer_operator) (void *, void *);