2011-11-24 Andrew MacLeod <amacleod@redhat.com>

	* optab.c (maybe_emit_atomic_exchange): New.  Try to emit an
	atomic_exchange pattern.
	(maybe_emit_sync_lock_test_and_set): New.  Try to emit an exchange
	using __sync_lock_test_and_set.
	(maybe_emit_compare_and_swap_exchange_loop): New. Try to emit an
	exchange using a compare_and_swap loop.
	(expand_sync_lock_test_and_set): New.  Expand sync_lock_test_and_set.
	(expand_atomic_test_and_set): New.  Expand test_and_set operation.
	(expand_atomic_exchange): Use new maybe_emit_* functions.
	(expand_atomic_store): Use new maybe_emit_* functions.
	* builtins.c (expand_builtin_sync_lock_test_and_set): Call
	expand_sync_lock_test_and_set routine.
	(expand_builtin_atomic_exchange): Remove parameter from call.
	(expand_builtin_atomic_clear): Use atomic_clear pattern if present.
	(expand_builtin_atomic_test_and_set): Add target and simply call
	expand_atomic_test_and_set.
	(expand_builtin): Add target to expand_builtin_atomic_test_and_set.
	* expr.h (expand_atomic_exchange): Add parameter.
	(expand_sync_lock_test_and_set): New prototype.
	(expand_atomic_test_and_set, expand_atomic_clear): New prototypes.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@181702 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 17 insertions, 19 deletions

diff --git a/gcc/builtins.c b/gcc/builtins.c
index 0fc5a420c82..c9c02d10550 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -5227,7 +5227,7 @@ expand_builtin_sync_lock_test_and_set (enum machine_mode mode, tree exp,
   mem = get_builtin_sync_mem (CALL_EXPR_ARG (exp, 0), mode);
   val = expand_expr_force_mode (CALL_EXPR_ARG (exp, 1), mode);
 
-  return expand_atomic_exchange (target, mem, val, MEMMODEL_ACQUIRE, true);
+  return expand_sync_lock_test_and_set (target, mem, val);
 }
 
 /* Expand the __sync_lock_release intrinsic.  EXP is the CALL_EXPR.  */
@@ -5291,7 +5291,7 @@ expand_builtin_atomic_exchange (enum machine_mode mode, tree exp, rtx target)
   mem = get_builtin_sync_mem (CALL_EXPR_ARG (exp, 0), mode);
   val = expand_expr_force_mode (CALL_EXPR_ARG (exp, 1), mode);
 
-  return expand_atomic_exchange (target, mem, val, model, false);
+  return expand_atomic_exchange (target, mem, val, model);
 }
 
 /* Expand the __atomic_compare_exchange intrinsic:
@@ -5482,6 +5482,11 @@ expand_builtin_atomic_fetch_op (enum machine_mode mode, tree exp, rtx target,
 }
 
 
+#ifndef HAVE_atomic_clear
+# define HAVE_atomic_clear 0
+# define gen_atomic_clear(x,y) (gcc_unreachable (), NULL_RTX)
+#endif
+
 /* Expand an atomic clear operation.
 	void _atomic_clear (BOOL *obj, enum memmodel)
    EXP is the call expression.  */
@@ -5503,6 +5508,12 @@ expand_builtin_atomic_clear (tree exp)
       return const0_rtx;
     }
 
+  if (HAVE_atomic_clear)
+    {
+      emit_insn (gen_atomic_clear (mem, model));
+      return const0_rtx;
+    }
+
   /* Try issuing an __atomic_store, and allow fallback to __sync_lock_release.
      Failing that, a store is issued by __atomic_store.  The only way this can
      fail is if the bool type is larger than a word size.  Unlikely, but
@@ -5519,9 +5530,9 @@ expand_builtin_atomic_clear (tree exp)
    EXP is the call expression.  */
 
 static rtx
-expand_builtin_atomic_test_and_set (tree exp)
+expand_builtin_atomic_test_and_set (tree exp, rtx target)
 {
-  rtx mem, ret;
+  rtx mem;
   enum memmodel model;
   enum machine_mode mode;
 
@@ -5529,20 +5540,7 @@ expand_builtin_atomic_test_and_set (tree exp)
   mem = get_builtin_sync_mem (CALL_EXPR_ARG (exp, 0), mode);
   model = get_memmodel (CALL_EXPR_ARG (exp, 1));
 
-  /* Try issuing an exchange.  If it is lock free, or if there is a limited
-     functionality __sync_lock_test_and_set, this will utilize it.  */
-  ret = expand_atomic_exchange (NULL_RTX, mem, const1_rtx, model, true);
-  if (ret)
-    return ret;
-
-  /* Otherwise, there is no lock free support for test and set.  Simply
-     perform a load and a store.  Since this presumes a non-atomic architecture,
-     also assume single threadedness and don't issue barriers either. */
-
-  ret = gen_reg_rtx (mode);
-  emit_move_insn (ret, mem);
-  emit_move_insn (mem, const1_rtx);
-  return ret;
+  return expand_atomic_test_and_set (target, mem, model);
 }
 
 
@@ -6711,7 +6709,7 @@ expand_builtin (tree exp, rtx target, rtx subtarget, enum machine_mode mode,
       break;
 
     case BUILT_IN_ATOMIC_TEST_AND_SET:
-      return expand_builtin_atomic_test_and_set (exp);
+      return expand_builtin_atomic_test_and_set (exp, target);
 
     case BUILT_IN_ATOMIC_CLEAR:
       return expand_builtin_atomic_clear (exp);