re PR debug/43479 (Missing DW_TAG_lexical_block+DW_TAG_variable)

	PR debug/43479
	* ira.c (adjust_cleared_regs): New function.
	(update_equiv_regs): Adjust cleared_regs in DEBUG_INSNs.

From-SVN: r157702

gcc/ChangeLog

 2010-03-24  Jakub Jelinek  <jakub@redhat.com>
 
+	PR debug/43479
+	* ira.c (adjust_cleared_regs): New function.
+	(update_equiv_regs): Adjust cleared_regs in DEBUG_INSNs.
+
 	PR debug/19192
 	PR debug/43479
 	* cfgexpand.c (gimple_assign_rhs_to_tree): Also set TREE_BLOCK

gcc/ira.c

 /* Integrated Register Allocator (IRA) entry point.
-   Copyright (C) 2006, 2007, 2008, 2009
+   Copyright (C) 2006, 2007, 2008, 2009, 2010
    Free Software Foundation, Inc.
    Contributed by Vladimir Makarov <vmakarov@redhat.com>.
 
@@ -2282,6 +2282,22 @@ no_equiv (rtx reg, const_rtx store ATTRIBUTE_UNUSED, void *data ATTRIBUTE_UNUSED
     }
 }
 
+/* In DEBUG_INSN location adjust REGs from CLEARED_REGS bitmap to the
+   equivalent replacement.  */
+
+static rtx
+adjust_cleared_regs (rtx loc, const_rtx old_rtx ATTRIBUTE_UNUSED, void *data)
+{
+  if (REG_P (loc))
+    {
+      bitmap cleared_regs = (bitmap) data;
+      if (bitmap_bit_p (cleared_regs, REGNO (loc)))
+	return simplify_replace_fn_rtx (*reg_equiv[REGNO (loc)].src_p,
+					NULL_RTX, adjust_cleared_regs, data);
+    }
+  return NULL_RTX;
+}
+
 /* Nonzero if we recorded an equivalence for a LABEL_REF.  */
 static int recorded_label_ref;
 
@@ -2717,13 +2733,29 @@ update_equiv_regs (void)
     }
 
   if (!bitmap_empty_p (cleared_regs))
-    FOR_EACH_BB (bb)
-      {
-	bitmap_and_compl_into (DF_LIVE_IN (bb), cleared_regs);
-	bitmap_and_compl_into (DF_LIVE_OUT (bb), cleared_regs);
-	bitmap_and_compl_into (DF_LR_IN (bb), cleared_regs);
-	bitmap_and_compl_into (DF_LR_OUT (bb), cleared_regs);
-      }
+    {
+      FOR_EACH_BB (bb)
+	{
+	  bitmap_and_compl_into (DF_LIVE_IN (bb), cleared_regs);
+	  bitmap_and_compl_into (DF_LIVE_OUT (bb), cleared_regs);
+	  bitmap_and_compl_into (DF_LR_IN (bb), cleared_regs);
+	  bitmap_and_compl_into (DF_LR_OUT (bb), cleared_regs);
+	}
+
+      /* Last pass - adjust debug insns referencing cleared regs.  */
+      if (MAY_HAVE_DEBUG_INSNS)
+	for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
+	  if (DEBUG_INSN_P (insn))
+	    {
+	      rtx old_loc = INSN_VAR_LOCATION_LOC (insn);
+	      INSN_VAR_LOCATION_LOC (insn)
+		= simplify_replace_fn_rtx (old_loc, NULL_RTX,
+					   adjust_cleared_regs,
+					   (void *) cleared_regs);
+	      if (old_loc != INSN_VAR_LOCATION_LOC (insn))
+		df_insn_rescan (insn);
+	    }
+    }
 
   BITMAP_FREE (cleared_regs);