dce.c (reset_unmarked_insns_debug_uses): New.

* dce.c (reset_unmarked_insns_debug_uses): New.
(delete_unmarked_insns): Skip debug insns.
(prescan_insns_for_dce): Likewise.
(rest_of_handle_ud_dce): Reset debug uses of removed sets.
* reg-stack.c (subst_stack_regs_in_debug_insn): Signal when no
active reg can be found.
(subst_all_stack_regs_in_debug_insn): New.  Reset debug insn then.
(convert_regs_1): Use it.

From-SVN: r174699

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 59bf1fc2c998e8601b78f8c0fd7ddb06275ea2de..c45fe7211b3a7a28627f3ef172cf544da2575f0b 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2011-06-06  Alexandre Oliva  <aoliva@redhat.com>
+
+       * dce.c (reset_unmarked_insns_debug_uses): New.
+       (delete_unmarked_insns): Skip debug insns.
+       (prescan_insns_for_dce): Likewise.
+       (rest_of_handle_ud_dce): Reset debug uses of removed sets.
+       * reg-stack.c (subst_stack_regs_in_debug_insn): Signal when no
+       active reg can be found.
+       (subst_all_stack_regs_in_debug_insn): New.  Reset debug insn then.
+       (convert_regs_1): Use it.
+
 2011-06-06  Alexandre Oliva  <aoliva@redhat.com>
 
        * tree-pretty-print.c (dump_function_header): Add flags.

diff --git a/gcc/dce.c b/gcc/dce.c
index ec54c6681b8a13b77f4761a936fbcea4f5919d0d..93464fedeede53e1e786db510bc1494415b5f16a 100644 (file)
--- a/gcc/dce.c
+++ b/gcc/dce.c
@@ -493,6 +493,43 @@ remove_reg_equal_equiv_notes_for_defs (rtx insn)
     remove_reg_equal_equiv_notes_for_regno (DF_REF_REGNO (*def_rec));
 }
 
+/* Scan all BBs for debug insns and reset those that reference values
+   defined in unmarked insns.  */
+
+static void
+reset_unmarked_insns_debug_uses (void)
+{
+  basic_block bb;
+  rtx insn, next;
+
+  FOR_EACH_BB_REVERSE (bb)
+    FOR_BB_INSNS_REVERSE_SAFE (bb, insn, next)
+      if (DEBUG_INSN_P (insn))
+       {
+         df_ref *use_rec;
+
+         for (use_rec = DF_INSN_USES (insn); *use_rec; use_rec++)
+           {
+             df_ref use = *use_rec;
+             struct df_link *defs;
+             for (defs = DF_REF_CHAIN (use); defs; defs = defs->next)
+               {
+                 rtx insn;
+                 if (DF_REF_IS_ARTIFICIAL (defs->ref))
+                   continue;
+                 insn = DF_REF_INSN (defs->ref);
+                 if (!marked_insn_p (insn))
+                   break;
+               }
+             if (!defs)
+               continue;
+             /* ??? FIXME could we propagate the values assigned to
+                each of the DEFs?  */
+             INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC ();
+             df_insn_rescan_debug_internal (insn);
+           }
+       }
+}
 
 /* Delete every instruction that hasn't been marked.  */
 
@@ -505,7 +542,7 @@ delete_unmarked_insns (void)
 
   FOR_EACH_BB_REVERSE (bb)
     FOR_BB_INSNS_REVERSE_SAFE (bb, insn, next)
-      if (INSN_P (insn))
+      if (NONDEBUG_INSN_P (insn))
        {
          /* Always delete no-op moves.  */
          if (noop_move_p (insn))
@@ -579,7 +616,7 @@ prescan_insns_for_dce (bool fast)
   FOR_EACH_BB (bb)
     {
       FOR_BB_INSNS_REVERSE_SAFE (bb, insn, prev)
-       if (INSN_P (insn))
+       if (NONDEBUG_INSN_P (insn))
          {
            /* Don't mark argument stores now.  They will be marked
               if needed when the associated CALL is marked.  */
@@ -713,6 +750,9 @@ rest_of_handle_ud_dce (void)
     }
   VEC_free (rtx, heap, worklist);
 
+  if (MAY_HAVE_DEBUG_INSNS)
+    reset_unmarked_insns_debug_uses ();
+
   /* Before any insns are deleted, we must remove the chains since
      they are not bidirectional.  */
   df_remove_problem (df_chain);

diff --git a/gcc/reg-stack.c b/gcc/reg-stack.c
index 60835c75528d0c09a9472bf89fe9d6ad06a715dc..dcde8920d7e037b5576ac0067e6556b8d7453b27 100644 (file)
--- a/gcc/reg-stack.c
+++ b/gcc/reg-stack.c
@@ -1333,6 +1333,11 @@ subst_stack_regs_in_debug_insn (rtx *loc, void *data)
     return 0;
 
   hard_regno = get_hard_regnum (regstack, *loc);
+
+  /* If we can't find an active register, reset this debug insn.  */
+  if (hard_regno == -1)
+    return 1;
+
   gcc_assert (hard_regno >= FIRST_STACK_REG);
 
   replace_reg (loc, hard_regno);
@@ -1340,6 +1345,23 @@ subst_stack_regs_in_debug_insn (rtx *loc, void *data)
   return -1;
 }
 
+/* Substitute hardware stack regs in debug insn INSN, using stack
+   layout REGSTACK.  If we can't find a hardware stack reg for any of
+   the REGs in it, reset the debug insn.  */
+
+static void
+subst_all_stack_regs_in_debug_insn (rtx insn, struct stack_def *regstack)
+{
+  int ret = for_each_rtx (&INSN_VAR_LOCATION_LOC (insn),
+                         subst_stack_regs_in_debug_insn,
+                         regstack);
+
+  if (ret == 1)
+    INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC ();
+  else
+    gcc_checking_assert (ret == 0);
+}
+
 /* Substitute new registers in PAT, which is part of INSN.  REGSTACK
    is the current register layout.  Return whether a control flow insn
    was deleted in the process.  */
@@ -2947,8 +2969,7 @@ convert_regs_1 (basic_block block)
            debug_insns_with_starting_stack++;
          else
            {
-             for_each_rtx (&PATTERN (insn), subst_stack_regs_in_debug_insn,
-                           &regstack);
+             subst_all_stack_regs_in_debug_insn (insn, &regstack);
 
              /* Nothing must ever die at a debug insn.  If something
                 is referenced in it that becomes dead, it should have
@@ -2986,8 +3007,7 @@ convert_regs_1 (basic_block block)
            continue;
 
          debug_insns_with_starting_stack--;
-         for_each_rtx (&PATTERN (insn), subst_stack_regs_in_debug_insn,
-                       &bi->stack_in);
+         subst_all_stack_regs_in_debug_insn (insn, &bi->stack_in);
        }
     }