re PR debug/47858 (IPA-SRA decreases quality of debug info)

	PR debug/47858
	* gimple.h (enum gimple_debug_subcode): Add GIMPLE_DEBUG_SOURCE_BIND.
	(gimple_build_debug_source_bind_stat): New prototype.
	(gimple_build_debug_source_bind): Define.
	(gimple_debug_source_bind_p, gimple_debug_source_bind_get_var,
	gimple_debug_source_bind_get_value,
	gimple_debug_source_bind_get_value_ptr,
	gimple_debug_source_bind_set_var,
	gimple_debug_source_bind_set_value): New inlines.
	* gimple.c (gimple_build_debug_source_bind_stat): New function.
	* gimple-pretty-print.c (dump_gimple_debug): Handle
	GIMPLE_DEBUG_SOURCE_BIND.
	* sese.c (rename_uses): Handle gimple_debug_source_bind_p.
	* tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Likewise.
	* tree-parloops.c (eliminate_local_variables,
	separate_decls_in_region): Likewise.
	(separate_decls_in_region_debug): Renamed from
	separate_decls_in_region_debug_bind.  Handle
	gimple_debug_source_bind_p.
	* tree.h (decl_debug_args_lookup, decl_debug_args_insert): New
	prototypes.
	(DECL_HAS_DEBUG_ARGS_P): Define.
	(struct tree_function_decl): Add has_debug_args_flag field.
	* tree.c (debug_args_for_decl): New variable.
	(decl_debug_args_lookup, decl_debug_args_insert): New functions.
	* tree-into-ssa.c (mark_def_sites): Handle uses in debug stmts.
	(rewrite_debug_stmt_uses): New function.
	(rewrite_stmt): Use it to rewrite debug stmt uses.
	* rtl.def (DEBUG_PARAMETER_REF): New.
	* rtl.h (DEBUG_PARAMETER_REF_DECL): Define.
	* cselib.c (rtx_equal_for_cselib_1, cselib_hash_rtx): Handle
	DEBUG_PARAMETER_REF.
	* rtl.c (rtx_equal_p_cb, rtx_equal_p, iterative_hash_rtx): Likewise.
	* print-rtl.c (print_rtx): Likewise.
	* tree-sra.c (sra_ipa_reset_debug_stmts): Prefer replacing of
	SSA_NAMEs with DEBUG_EXPR_DECLs initialized in source bind
	debug stmts in the first bb.
	* tree-inline.c (remap_ssa_name): If remapping default def
	of a PARM_DECL fails, map to a DEBUG_EXPR_DECL set in
	a source bind debug stmt.
	(remap_gimple_stmt): Handle gimple_debug_source_bind_p.
	(maybe_move_debug_stmts_to_successors): Likewise.
	(copy_debug_stmt): Likewise.  Avoid shadowing a variable.
	(tree_function_versioning): If DECL_HAS_DEBUG_ARGS_P, copy
	debug args vector from old_decl to new_decl.
	* ipa-prop.c (ipa_modify_call_arguments): For optimized away
	or modified parameters, add debug bind stmts before call
	setting DEBUG_EXPR_DECL which is remembered in debug args
	vector.
	* cfgexpand.c (expand_call_stmt): Call expand_debug_expr
	on DECL_DEBUG_EXPRs from debug args vector.
	(expand_debug_source_expr): New function.
	(expand_debug_locations): Use it for source bind insns.
	(expand_gimple_basic_block): Handle gimple_debug_source_bind_p.
	* var-tracking.c (prepare_call_arguments): Add debug args
	to call_arguments if any.
	* dwarf2out.c (dwarf_stack_op_name, size_of_loc_descr,
	output_loc_operands, output_loc_operands_raw,
	resolve_addr_in_expr, compare_loc_operands): Handle
	DW_OP_GNU_parameter_ref.
	(get_ref_die_offset, parameter_ref_descriptor): New functions.
	(mem_loc_descriptor): Handle DEBUG_PARAMETER_REF.
	(gen_subprogram_die): Handle parameters identified by
	DEBUG_PARAMETER_REF.

	* dwarf2.h (enum dwarf_location_atom): Add DW_OP_GNU_parameter_ref.

From-SVN: r175288

1 files changed, 70 insertions, 11 deletions

diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
index 322abb5..b9bb23d 100644
--- a/gcc/tree-sra.c
+++ b/gcc/tree-sra.c
@@ -1,7 +1,7 @@
 /* Scalar Replacement of Aggregates (SRA) converts some structure
    references into scalar references, exposing them to the scalar
    optimizers.
-   Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
+   Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
    Contributed by Martin Jambor <mjambor@suse.cz>
 
 This file is part of GCC.
@@ -4282,28 +4282,87 @@ static void
 sra_ipa_reset_debug_stmts (ipa_parm_adjustment_vec adjustments)
 {
   int i, len;
+  gimple_stmt_iterator *gsip = NULL, gsi;
 
+  if (MAY_HAVE_DEBUG_STMTS && single_succ_p (ENTRY_BLOCK_PTR))
+    {
+      gsi = gsi_after_labels (single_succ (ENTRY_BLOCK_PTR));
+      gsip = &gsi;
+    }
   len = VEC_length (ipa_parm_adjustment_t, adjustments);
   for (i = 0; i < len; i++)
     {
       struct ipa_parm_adjustment *adj;
       imm_use_iterator ui;
-      gimple stmt;
-      tree name;
+      gimple stmt, def_temp;
+      tree name, vexpr, copy = NULL_TREE;
+      use_operand_p use_p;
 
       adj = VEC_index (ipa_parm_adjustment_t, adjustments, i);
       if (adj->copy_param || !is_gimple_reg (adj->base))
 	continue;
       name = gimple_default_def (cfun, adj->base);
-      if (!name)
-	continue;
-      FOR_EACH_IMM_USE_STMT (stmt, ui, name)
+      vexpr = NULL;
+      if (name)
+	FOR_EACH_IMM_USE_STMT (stmt, ui, name)
+	  {
+	    /* All other users must have been removed by
+	       ipa_sra_modify_function_body.  */
+	    gcc_assert (is_gimple_debug (stmt));
+	    if (vexpr == NULL && gsip != NULL)
+	      {
+		gcc_assert (TREE_CODE (adj->base) == PARM_DECL);
+		vexpr = make_node (DEBUG_EXPR_DECL);
+		def_temp = gimple_build_debug_source_bind (vexpr, adj->base,
+							   NULL);
+		DECL_ARTIFICIAL (vexpr) = 1;
+		TREE_TYPE (vexpr) = TREE_TYPE (name);
+		DECL_MODE (vexpr) = DECL_MODE (adj->base);
+		gsi_insert_before (gsip, def_temp, GSI_SAME_STMT);
+	      }
+	    if (vexpr)
+	      {
+		FOR_EACH_IMM_USE_ON_STMT (use_p, ui)
+		  SET_USE (use_p, vexpr);
+	      }
+	    else
+	      gimple_debug_bind_reset_value (stmt);
+	    update_stmt (stmt);
+	  }
+      /* Create a VAR_DECL for debug info purposes.  */
+      if (!DECL_IGNORED_P (adj->base))
 	{
-	  /* All other users must have been removed by
-	     ipa_sra_modify_function_body.  */
-	  gcc_assert (is_gimple_debug (stmt));
-	  gimple_debug_bind_reset_value (stmt);
-	  update_stmt (stmt);
+	  copy = build_decl (DECL_SOURCE_LOCATION (current_function_decl),
+			     VAR_DECL, DECL_NAME (adj->base),
+			     TREE_TYPE (adj->base));
+	  if (DECL_PT_UID_SET_P (adj->base))
+	    SET_DECL_PT_UID (copy, DECL_PT_UID (adj->base));
+	  TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (adj->base);
+	  TREE_READONLY (copy) = TREE_READONLY (adj->base);
+	  TREE_THIS_VOLATILE (copy) = TREE_THIS_VOLATILE (adj->base);
+	  DECL_GIMPLE_REG_P (copy) = DECL_GIMPLE_REG_P (adj->base);
+	  DECL_ARTIFICIAL (copy) = DECL_ARTIFICIAL (adj->base);
+	  DECL_IGNORED_P (copy) = DECL_IGNORED_P (adj->base);
+	  DECL_ABSTRACT_ORIGIN (copy) = DECL_ORIGIN (adj->base);
+	  DECL_SEEN_IN_BIND_EXPR_P (copy) = 1;
+	  SET_DECL_RTL (copy, 0);
+	  TREE_USED (copy) = 1;
+	  DECL_CONTEXT (copy) = current_function_decl;
+	  add_referenced_var (copy);
+	  add_local_decl (cfun, copy);
+	  DECL_CHAIN (copy) =
+	    BLOCK_VARS (DECL_INITIAL (current_function_decl));
+	  BLOCK_VARS (DECL_INITIAL (current_function_decl)) = copy;
+	}
+      if (gsip != NULL && copy && target_for_debug_bind (adj->base))
+	{
+	  gcc_assert (TREE_CODE (adj->base) == PARM_DECL);
+	  if (vexpr)
+	    def_temp = gimple_build_debug_bind (copy, vexpr, NULL);
+	  else
+	    def_temp = gimple_build_debug_source_bind (copy, adj->base,
+						       NULL);
+	  gsi_insert_before (gsip, def_temp, GSI_SAME_STMT);
 	}
     }
 }