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, 39 insertions, 2 deletions

diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
index 10c11d4..aec1920 100644
--- a/gcc/ipa-prop.c
+++ b/gcc/ipa-prop.c
@@ -1,5 +1,5 @@
 /* Interprocedural analyses.
-   Copyright (C) 2005, 2007, 2008, 2009, 2010
+   Copyright (C) 2005, 2007, 2008, 2009, 2010, 2011
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -2393,6 +2393,7 @@ ipa_modify_call_arguments (struct cgraph_edge *cs, gimple stmt,
 			   ipa_parm_adjustment_vec adjustments)
 {
   VEC(tree, heap) *vargs;
+  VEC(tree, gc) **debug_args = NULL;
   gimple new_stmt;
   gimple_stmt_iterator gsi;
   tree callee_decl;
@@ -2400,6 +2401,7 @@ ipa_modify_call_arguments (struct cgraph_edge *cs, gimple stmt,
 
   len = VEC_length (ipa_parm_adjustment_t, adjustments);
   vargs = VEC_alloc (tree, heap, len);
+  callee_decl = !cs ? gimple_call_fndecl (stmt) : cs->callee->decl;
 
   gsi = gsi_for_stmt (stmt);
   for (i = 0; i < len; i++)
@@ -2490,6 +2492,42 @@ ipa_modify_call_arguments (struct cgraph_edge *cs, gimple stmt,
 					   NULL, true, GSI_SAME_STMT);
 	  VEC_quick_push (tree, vargs, expr);
 	}
+      if (!adj->copy_param && MAY_HAVE_DEBUG_STMTS)
+	{
+	  unsigned int ix;
+	  tree ddecl = NULL_TREE, origin = DECL_ORIGIN (adj->base), arg;
+	  gimple def_temp;
+
+	  arg = gimple_call_arg (stmt, adj->base_index);
+	  if (!useless_type_conversion_p (TREE_TYPE (origin), TREE_TYPE (arg)))
+	    {
+	      if (!fold_convertible_p (TREE_TYPE (origin), arg))
+		continue;
+	      arg = fold_convert_loc (gimple_location (stmt),
+				      TREE_TYPE (origin), arg);
+	    }
+	  if (debug_args == NULL)
+	    debug_args = decl_debug_args_insert (callee_decl);
+	  for (ix = 0; VEC_iterate (tree, *debug_args, ix, ddecl); ix += 2)
+	    if (ddecl == origin)
+	      {
+		ddecl = VEC_index (tree, *debug_args, ix + 1);
+		break;
+	      }
+	  if (ddecl == NULL)
+	    {
+	      ddecl = make_node (DEBUG_EXPR_DECL);
+	      DECL_ARTIFICIAL (ddecl) = 1;
+	      TREE_TYPE (ddecl) = TREE_TYPE (origin);
+	      DECL_MODE (ddecl) = DECL_MODE (origin);
+
+	      VEC_safe_push (tree, gc, *debug_args, origin);
+	      VEC_safe_push (tree, gc, *debug_args, ddecl);
+	    }
+	  def_temp = gimple_build_debug_bind (ddecl, unshare_expr (arg),
+					      stmt);
+	  gsi_insert_before (&gsi, def_temp, GSI_SAME_STMT);
+	}
     }
 
   if (dump_file && (dump_flags & TDF_DETAILS))
@@ -2498,7 +2536,6 @@ ipa_modify_call_arguments (struct cgraph_edge *cs, gimple stmt,
       print_gimple_stmt (dump_file, gsi_stmt (gsi), 0, 0);
     }
 
-  callee_decl = !cs ? gimple_call_fndecl (stmt) : cs->callee->decl;
   new_stmt = gimple_build_call_vec (callee_decl, vargs);
   VEC_free (tree, heap, vargs);
   if (gimple_call_lhs (stmt))