i386.c (insn_is_function_arg): Add check on CALL instruction.

        * config/i386/i386.c (insn_is_function_arg) : Add check on CALL
        instruction.
        (ix86_dependencies_evaluation_hook): Insert dependencies in all
        predecessors of call block for non-trivial region avoiding creation
        of loop-carried dependency to avoid cross-block motion of HW registers.

From-SVN: r192842

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 96e604565a7d25c0566681569cdeabd23f9ebd76..5f3c8ac13d63a9c5c16baf4662f8f69b171405cf 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2012-10-23  Yuri Rumyantsev  <ysrumyan@gmail.com>
+
+       * config/i386/i386.c (insn_is_function_arg) : Add check on CALL
+       instruction.
+       (ix86_dependencies_evaluation_hook): Insert dependencies in all
+       predecessors of call block for non-trivial region avoiding creation
+       of loop-carried dependency to avoid cross-block motion of HW registers.
+
 2012-10-26  Richard Biener  <rguenther@suse.de>
 
        PR middle-end/54824

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 2a9db18b173ef6d111a65e75248bcf993e5b84f2..b575dc20aae1084f876e8963b364d523620980eb 100644 (file)
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -24454,6 +24454,9 @@ insn_is_function_arg (rtx insn, bool* is_spilled)
 
   if (!NONDEBUG_INSN_P (insn))
     return false;
+  /* Call instructions are not movable, ignore it.  */
+  if (CALL_P (insn))
+    return false;
   insn = PATTERN (insn);
   if (GET_CODE (insn) == PARALLEL)
     insn = XVECEXP (insn, 0, 0);
@@ -24586,18 +24589,26 @@ ix86_dependencies_evaluation_hook (rtx head, rtx tail)
        first_arg = add_parameter_dependencies (insn, head);
        if (first_arg)
          {
-           /* Check if first argument has dependee out of its home block.  */
-           sd_iterator_def sd_it1;
-           dep_t dep1;
-           FOR_EACH_DEP (first_arg, SD_LIST_BACK, sd_it1, dep1)
+           /* Add dependee for first argument to predecessors if only
+              region contains more than one block.  */
+           basic_block bb =  BLOCK_FOR_INSN (insn);
+           int rgn = CONTAINING_RGN (bb->index);
+           int nr_blks = RGN_NR_BLOCKS (rgn);
+           /* Skip trivial regions and region head blocks that can have
+              predecessors outside of region.  */
+           if (nr_blks > 1 && BLOCK_TO_BB (bb->index) != 0)
              {
-               rtx dee;
-               dee = DEP_PRO (dep1);
-               if (!NONDEBUG_INSN_P (dee))
-                 continue;
-               if (BLOCK_FOR_INSN (dee) != BLOCK_FOR_INSN (first_arg))
-                 /* Must add dependee for first argument in dee's block.  */
-                 add_dependee_for_func_arg (first_arg, BLOCK_FOR_INSN (dee));
+               edge e;
+               edge_iterator ei;
+               /* Assume that region is SCC, i.e. all immediate predecessors
+                  of non-head block are in the same region.  */
+               FOR_EACH_EDGE (e, ei, bb->preds)
+                 {
+                   /* Avoid creating of loop-carried dependencies through
+                      using topological odering in region.  */
+                   if (BLOCK_TO_BB (bb->index) > BLOCK_TO_BB (e->src->index))
+                     add_dependee_for_func_arg (first_arg, e->src); 
+                 }
              }
            insn = first_arg;
          }