re PR middle-end/54893 (unable to access volatile variable within relaxed transaction)

	PR middle-end/54893
        * trans-mem.c (diagnose_tm_1_op): Allow volatiles inside relaxed
        transactions.

From-SVN: r192549

gcc/ChangeLog

 2012-10-17  Aldy Hernandez  <aldyh@redhat.com>
 
+	PR middle-end/54893
+        * trans-mem.c (diagnose_tm_1_op): Allow volatiles inside relaxed
+        transactions.
+
+2012-10-17  Aldy Hernandez  <aldyh@redhat.com>
+
 	PR rtl-optimization/54900
 	* ifcvt.c (noce_can_store_speculate_p): Call
 	memory_must_be_modified_in_insn_p.

gcc/testsuite/c-c++-common/tm/pr54893.c

+/* { dg-do compile } */
+/* { dg-options "-fgnu-tm -fdump-ipa-tmipa" } */
+
+/* Test that volatiles are allowed inside relaxed transactions.  */
+
+volatile int test_var = 0;
+
+int main()
+{
+  __transaction_relaxed {
+    test_var++;
+  }
+}
+
+/* { dg-final { scan-ipa-dump "GTMA_DOES_GO_IRREVOCABLE" "tmipa" } } */
+/* { dg-final { cleanup-ipa-dump "tmipa" } } */

gcc/trans-mem.c

@@ -548,6 +548,15 @@ struct diagnose_tm
   gimple stmt;
 };
 
+/* Return true if T is a volatile variable of some kind.  */
+
+static bool
+volatile_var_p (tree t)
+{
+  return (SSA_VAR_P (t)
+	  && TREE_THIS_VOLATILE (TREE_TYPE (t)));
+}
+
 /* Tree callback function for diagnose_tm pass.  */
 
 static tree
@@ -556,13 +565,9 @@ diagnose_tm_1_op (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
 {
   struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
   struct diagnose_tm *d = (struct diagnose_tm *) wi->info;
-  enum tree_code code = TREE_CODE (*tp);
 
-  if ((code == VAR_DECL
-       || code == RESULT_DECL
-       || code == PARM_DECL)
-      && d->block_flags & (DIAG_TM_SAFE | DIAG_TM_RELAXED)
-      && TREE_THIS_VOLATILE (TREE_TYPE (*tp))
+  if (volatile_var_p (*tp)
+      && d->block_flags & DIAG_TM_SAFE
       && !d->saw_volatile)
     {
       d->saw_volatile = 1;
@@ -3782,7 +3787,22 @@ ipa_tm_scan_irr_block (basic_block bb)
       gimple stmt = gsi_stmt (gsi);
       switch (gimple_code (stmt))
 	{
+	case GIMPLE_ASSIGN:
+	  if (gimple_assign_single_p (stmt))
+	    {
+	      tree lhs = gimple_assign_lhs (stmt);
+	      tree rhs = gimple_assign_rhs1 (stmt);
+	      if (volatile_var_p (lhs) || volatile_var_p (rhs))
+		return true;
+	    }
+	  break;
+
 	case GIMPLE_CALL:
+	  {
+	    tree lhs = gimple_call_lhs (stmt);
+	    if (lhs && volatile_var_p (lhs))
+	      return true;
+
 	    if (is_tm_pure_call (stmt))
 	      break;
 
@@ -3816,6 +3836,7 @@ ipa_tm_scan_irr_block (basic_block bb)
 		  return true;
 	      }
 	    break;
+	  }
 
 	case GIMPLE_ASM:
 	  /* ??? The Approved Method of indicating that an inline