trans-mem.c (expand_transaction): Do not set PR_INSTRUMENTEDCODE if GTMA_HAS_NO_INSTRUMENTATION.

	* trans-mem.c (expand_transaction): Do not set PR_INSTRUMENTEDCODE
	if GTMA_HAS_NO_INSTRUMENTATION.
	(generate_tm_state): Keep GTMA_HAS_NO_INSTRUMENTATION bit.
	(ipa_tm_transform_transaction): Set GTMA_HAS_NO_INSTRUMENTATION.
	* gimple.h (GTMA_HAS_NO_INSTRUMENTATION): Define.
	* gimple-pretty-print.c (dump_gimple_transaction): Handle
	GTMA_HAS_NO_INSTRUMENTATION.

From-SVN: r196562

gcc/ChangeLog

+2013-02-27  Aldy Hernandez  <aldyh@redhat.com>
+
+	* trans-mem.c (expand_transaction): Do not set PR_INSTRUMENTEDCODE
+	if GTMA_HAS_NO_INSTRUMENTATION.
+	(generate_tm_state): Keep GTMA_HAS_NO_INSTRUMENTATION bit.
+	(ipa_tm_transform_transaction): Set GTMA_HAS_NO_INSTRUMENTATION.
+	* gimple.h (GTMA_HAS_NO_INSTRUMENTATION): Define.
+	* gimple-pretty-print.c (dump_gimple_transaction): Handle
+	GTMA_HAS_NO_INSTRUMENTATION.
+
+2013-02-25  Aldy Hernandez  <aldyh@redhat.com>
+
 2013-03-08  Jakub Jelinek  <jakub@redhat.com>
 
 	* config/gnu-user.h (LIBTSAN_EARLY_SPEC): Don't link against

gcc/gimple-pretty-print.c

@@ -1399,6 +1399,11 @@ dump_gimple_transaction (pretty_printer *buffer, gimple gs, int spc, int flags)
 		  pp_string (buffer, "GTMA_DOES_GO_IRREVOCABLE ");
 		  subcode &= ~GTMA_DOES_GO_IRREVOCABLE;
 		}
+	      if (subcode & GTMA_HAS_NO_INSTRUMENTATION)
+		{
+		  pp_string (buffer, "GTMA_HAS_NO_INSTRUMENTATION ");
+		  subcode &= ~GTMA_HAS_NO_INSTRUMENTATION;
+		}
 	      if (subcode)
 		pp_printf (buffer, "0x%x ", subcode);
 	      pp_string (buffer, "]");

gcc/gimple.h

@@ -661,6 +661,9 @@ struct GTY(()) gimple_statement_omp_atomic_store {
    tell the runtime that it should begin the transaction in
    serial-irrevocable mode.  */
 #define GTMA_DOES_GO_IRREVOCABLE	(1u << 6)
+/* The transaction contains no instrumentation code whatsover, most
+   likely because it is guaranteed to go irrevocable upon entry.  */
+#define GTMA_HAS_NO_INSTRUMENTATION	(1u << 7)
 
 struct GTY(()) gimple_statement_transaction
 {

gcc/testsuite/gcc.dg/tm/instrumented-mask.c

+/* { dg-do compile } */
+/* { dg-options "-fgnu-tm -fdump-tree-tmmark" } */
+
+/* If we're sure to go irrevocable, as in the case below, do not pass
+   PR_INSTRUMENTEDCODE to the run-time if there is nothing
+   instrumented within the transaction.  */
+
+int
+main()
+{
+  __transaction_relaxed { __asm__(""); }
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times " instrumentedCode" 0 "tmmark" } } */
+/* { dg-final { cleanup-tree-dump "tmmark" } } */

gcc/trans-mem.c

@@ -2602,7 +2602,7 @@ expand_transaction (struct tm_region *region, void *data ATTRIBUTE_UNUSED)
       flags |= PR_HASNOABORT;
     if ((subcode & GTMA_HAVE_STORE) == 0)
       flags |= PR_READONLY;
-    if (inst_edge)
+    if (inst_edge && !(subcode & GTMA_HAS_NO_INSTRUMENTATION))
       flags |= PR_INSTRUMENTEDCODE;
     if (uninst_edge)
       flags |= PR_UNINSTRUMENTEDCODE;
@@ -2806,7 +2806,8 @@ generate_tm_state (struct tm_region *region, void *data ATTRIBUTE_UNUSED)
 
       if (subcode & GTMA_DOES_GO_IRREVOCABLE)
 	subcode &= (GTMA_DECLARATION_MASK | GTMA_DOES_GO_IRREVOCABLE
-		    | GTMA_MAY_ENTER_IRREVOCABLE);
+		    | GTMA_MAY_ENTER_IRREVOCABLE
+		    | GTMA_HAS_NO_INSTRUMENTATION);
       else
 	subcode &= GTMA_DECLARATION_MASK;
       gimple_transaction_set_subcode (region->transaction_stmt, subcode);
@@ -5069,8 +5070,9 @@ ipa_tm_transform_transaction (struct cgraph_node *node)
 	  && bitmap_bit_p (d->irrevocable_blocks_normal,
 			   region->entry_block->index))
 	{
-	  transaction_subcode_ior (region, GTMA_DOES_GO_IRREVOCABLE);
-	  transaction_subcode_ior (region, GTMA_MAY_ENTER_IRREVOCABLE);
+	  transaction_subcode_ior (region, GTMA_DOES_GO_IRREVOCABLE
+				           | GTMA_MAY_ENTER_IRREVOCABLE
+				   	   | GTMA_HAS_NO_INSTRUMENTATION);
 	  continue;
 	}