SMS: Support instructions with REG_INC_NOTE

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@179381 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 35 insertions, 5 deletions

diff --git a/gcc/ddg.c b/gcc/ddg.c
index 856fa4e6800..2b1cfe827b9 100644
--- a/gcc/ddg.c
+++ b/gcc/ddg.c
@@ -145,6 +145,27 @@ mem_access_insn_p (rtx insn)
   return rtx_mem_access_p (PATTERN (insn));
 }
 
+/* Return true if DEF_INSN contains address being auto-inc or auto-dec
+   which is used in USE_INSN.  Otherwise return false.  The result is
+   being used to decide whether to remove the edge between def_insn and
+   use_insn when -fmodulo-sched-allow-regmoves is set.  This function
+   doesn't need to consider the specific address register; no reg_moves
+   will be allowed for any life range defined by def_insn and used
+   by use_insn, if use_insn uses an address register auto-inc'ed by
+   def_insn.  */
+bool
+autoinc_var_is_used_p (rtx def_insn, rtx use_insn)
+{
+  rtx note;
+
+  for (note = REG_NOTES (def_insn); note; note = XEXP (note, 1))
+    if (REG_NOTE_KIND (note) == REG_INC
+	&& reg_referenced_p (XEXP (note, 0), PATTERN (use_insn)))
+      return true;
+
+  return false;
+}
+
 /* Computes the dependence parameters (latency, distance etc.), creates
    a ddg_edge and adds it to the given DDG.  */
 static void
@@ -173,10 +194,15 @@ create_ddg_dep_from_intra_loop_link (ddg_ptr g, ddg_node_ptr src_node,
      compensate for that by generating reg-moves based on the life-range
      analysis.  The anti-deps that will be deleted are the ones which
      have true-deps edges in the opposite direction (in other words
-     the kernel has only one def of the relevant register).  TODO:
-     support the removal of all anti-deps edges, i.e. including those
+     the kernel has only one def of the relevant register).
+     If the address that is being auto-inc or auto-dec in DEST_NODE
+     is used in SRC_NODE then do not remove the edge to make sure
+     reg-moves will not be created for this address.  
+     TODO: support the removal of all anti-deps edges, i.e. including those
      whose register has multiple defs in the loop.  */
-  if (flag_modulo_sched_allow_regmoves && (t == ANTI_DEP && dt == REG_DEP))
+  if (flag_modulo_sched_allow_regmoves 
+      && (t == ANTI_DEP && dt == REG_DEP)
+      && !autoinc_var_is_used_p (dest_node->insn, src_node->insn))
     {
       rtx set;
 
@@ -302,10 +328,14 @@ add_cross_iteration_register_deps (ddg_ptr g, df_ref last_def)
 	  gcc_assert (first_def_node);
 
          /* Always create the edge if the use node is a branch in
-            order to prevent the creation of reg-moves.  */
+            order to prevent the creation of reg-moves.  
+            If the address that is being auto-inc or auto-dec in LAST_DEF
+            is used in USE_INSN then do not remove the edge to make sure
+            reg-moves will not be created for that address.  */
           if (DF_REF_ID (last_def) != DF_REF_ID (first_def)
               || !flag_modulo_sched_allow_regmoves
-	      || JUMP_P (use_node->insn))
+	      || JUMP_P (use_node->insn)
+              || autoinc_var_is_used_p (DF_REF_INSN (last_def), use_insn))
             create_ddg_dep_no_link (g, use_node, first_def_node, ANTI_DEP,
                                     REG_DEP, 1);