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Introduce parser-time optimization that moves function's argument values to registers.

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For functions with the optimization applied:
 - vm puts arguments values immediately to registers without putting them to variables in lexical environment;
 - number of arguments is extracted from corresponding 'reg_var_decl' instruction's argument;
 - for functions that also don't have local variables, lexical environments are not created.

JerryScript-DCO-1.0-Signed-off-by: Ruben Ayrapetyan r.ayrapetyan@samsung.com
This commit is contained in:
Ruben Ayrapetyan
2015-10-26 16:23:06 +03:00
parent 46c65985e5
commit 1fe2817457
16 changed files with 604 additions and 194 deletions
Download Patch File Download Diff File Expand all files Collapse all files
jerry-core/parser/js/parser.cpp
+165 -28
View File
@@ -1852,18 +1852,19 @@ static jsp_operand_t
parse_variable_declaration (void)
{
current_token_must_be (TOK_NAME);
const jsp_operand_t name = literal_operand (token_data_as_lit_cp ());
if (!dumper_variable_declaration_exists (token_data_as_lit_cp ()))
const lit_cpointer_t lit_cp = token_data_as_lit_cp ();
const jsp_operand_t name = literal_operand (lit_cp);
if (!scopes_tree_variable_declaration_exists (STACK_TOP (scopes), lit_cp))
{
jsp_early_error_check_for_eval_and_arguments_in_strict_mode (literal_operand (token_data_as_lit_cp ()),
is_strict_mode (),
tok.loc);
jsp_early_error_check_for_eval_and_arguments_in_strict_mode (name, is_strict_mode (), tok.loc);
dump_variable_declaration (token_data_as_lit_cp ());
dump_variable_declaration (lit_cp);
}
skip_newlines ();
if (token_is (TOK_EQ))
{
skip_newlines ();
@@ -3014,7 +3015,7 @@ parse_source_element_list (bool is_global, /**< flag, indicating that we parsing
check_directive_prologue_for_use_strict ();
dump_reg_var_decl_for_rewrite ();
vm_instr_counter_t reg_var_decl_oc = dump_reg_var_decl_for_rewrite ();
if (inside_eval
&& !inside_function)
@@ -3054,8 +3055,6 @@ parse_source_element_list (bool is_global, /**< flag, indicating that we parsing
scope_flags = (opcode_scope_code_flags_t) (scope_flags | OPCODE_SCOPE_CODE_FLAGS_NOT_REF_EVAL_IDENTIFIER);
}
rewrite_scope_code_flags (scope_code_flags_oc, scope_flags);
#ifdef CONFIG_PARSER_ENABLE_PARSE_TIME_BYTE_CODE_OPTIMIZER
if (is_try_replace_local_vars_with_regs
&& fe_scope_tree->type == SCOPE_TYPE_FUNCTION)
@@ -3083,30 +3082,167 @@ parse_source_element_list (bool is_global, /**< flag, indicating that we parsing
/* no subscopes, as no function declarations / eval etc. in the scope */
JERRY_ASSERT (fe_scope_tree->t.children_num == 0);
bool are_all_vars_replaced = true;
for (vm_instr_counter_t var_decl_pos = 0;
var_decl_pos < linked_list_get_length (fe_scope_tree->var_decls);
var_decl_pos++)
{
op_meta *om_p = (op_meta *) linked_list_element (fe_scope_tree->var_decls, var_decl_pos);
vm_instr_counter_t instr_pos = 0u;
if (!dumper_try_replace_var_with_reg (fe_scope_tree, om_p))
const vm_instr_counter_t header_oc = instr_pos++;
op_meta header_opm = scopes_tree_op_meta (fe_scope_tree, header_oc);
JERRY_ASSERT (header_opm.op.op_idx == VM_OP_FUNC_EXPR_N || header_opm.op.op_idx == VM_OP_FUNC_DECL_N);
vm_instr_counter_t function_end_pos = instr_pos;
while (true)
{
op_meta meta_opm = scopes_tree_op_meta (fe_scope_tree, function_end_pos);
JERRY_ASSERT (meta_opm.op.op_idx == VM_OP_META);
opcode_meta_type meta_type = (opcode_meta_type) meta_opm.op.data.meta.type;
if (meta_type == OPCODE_META_TYPE_FUNCTION_END)
{
are_all_vars_replaced = false;
/* marker of function argument list end reached */
break;
}
else
{
JERRY_ASSERT (meta_type == OPCODE_META_TYPE_VARG);
function_end_pos++;
}
}
if (are_all_vars_replaced)
{
/*
* All local variables were replaced with registers, so variable declarations could be removed.
*
* TODO:
* Support removal of a particular variable declaration, without removing the whole list.
*/
uint32_t args_num = (uint32_t) (function_end_pos - instr_pos);
linked_list_free (fe_scope_tree->var_decls);
fe_scope_tree->var_decls = linked_list_init (sizeof (op_meta));
dumper_start_move_of_vars_to_regs ();
/* remove declarations of variables with names equal to an argument's name */
vm_instr_counter_t var_decl_pos = 0;
while (var_decl_pos < linked_list_get_length (fe_scope_tree->var_decls))
{
op_meta *om_p = (op_meta *) linked_list_element (fe_scope_tree->var_decls, var_decl_pos);
bool is_removed = false;
for (vm_instr_counter_t arg_index = instr_pos;
arg_index < function_end_pos;
arg_index++)
{
op_meta meta_opm = scopes_tree_op_meta (fe_scope_tree, arg_index);
JERRY_ASSERT (meta_opm.op.op_idx == VM_OP_META);
JERRY_ASSERT (meta_opm.op.data.meta.data_1 == VM_IDX_REWRITE_LITERAL_UID);
JERRY_ASSERT (om_p->op.data.var_decl.variable_name == VM_IDX_REWRITE_LITERAL_UID);
if (meta_opm.lit_id[1].packed_value == om_p->lit_id[0].packed_value)
{
linked_list_remove_element (fe_scope_tree->var_decls, var_decl_pos);
is_removed = true;
break;
}
}
if (!is_removed)
{
if (!dumper_try_replace_identifier_name_with_reg (fe_scope_tree, om_p))
{
var_decl_pos++;
}
else
{
linked_list_remove_element (fe_scope_tree->var_decls, var_decl_pos);
}
}
}
if (dumper_start_move_of_args_to_regs (args_num))
{
scope_flags = (opcode_scope_code_flags_t) (scope_flags | OPCODE_SCOPE_CODE_FLAGS_ARGUMENTS_ON_REGISTERS);
JERRY_ASSERT (linked_list_get_length (fe_scope_tree->var_decls) == 0);
scope_flags = (opcode_scope_code_flags_t) (scope_flags | OPCODE_SCOPE_CODE_FLAGS_NO_LEX_ENV);
/* at this point all arguments can be moved to registers */
if (header_opm.op.op_idx == VM_OP_FUNC_EXPR_N)
{
header_opm.op.data.func_expr_n.arg_list = 0;
}
else
{
JERRY_ASSERT (header_opm.op.op_idx == VM_OP_FUNC_DECL_N);
header_opm.op.data.func_decl_n.arg_list = 0;
}
scopes_tree_set_op_meta (fe_scope_tree, header_oc, header_opm);
/*
* Mark duplicated arguments names as empty,
* leaving only last declaration for each duplicated
* argument name
*/
for (vm_instr_counter_t arg1_index = instr_pos;
arg1_index < function_end_pos;
arg1_index++)
{
op_meta meta_opm1 = scopes_tree_op_meta (fe_scope_tree, arg1_index);
JERRY_ASSERT (meta_opm1.op.op_idx == VM_OP_META);
for (vm_instr_counter_t arg2_index = (vm_instr_counter_t) (arg1_index + 1u);
arg2_index < function_end_pos;
arg2_index++)
{
op_meta meta_opm2 = scopes_tree_op_meta (fe_scope_tree, arg2_index);
JERRY_ASSERT (meta_opm2.op.op_idx == VM_OP_META);
if (meta_opm1.lit_id[1].packed_value == meta_opm2.lit_id[1].packed_value)
{
meta_opm1.op.data.meta.data_1 = VM_IDX_EMPTY;
meta_opm1.lit_id[1] = NOT_A_LITERAL;
scopes_tree_set_op_meta (fe_scope_tree, arg1_index, meta_opm1);
break;
}
}
}
while (true)
{
op_meta meta_opm = scopes_tree_op_meta (fe_scope_tree, instr_pos);
JERRY_ASSERT (meta_opm.op.op_idx == VM_OP_META);
opcode_meta_type meta_type = (opcode_meta_type) meta_opm.op.data.meta.type;
if (meta_type == OPCODE_META_TYPE_FUNCTION_END)
{
/* marker of function argument list end reached */
break;
}
else
{
JERRY_ASSERT (meta_type == OPCODE_META_TYPE_VARG);
if (meta_opm.op.data.meta.data_1 == VM_IDX_EMPTY)
{
JERRY_ASSERT (meta_opm.lit_id[1].packed_value == NOT_A_LITERAL.packed_value);
dumper_alloc_reg_for_unused_arg ();
}
else
{
/* the varg specifies argument name, and so should be a string literal */
JERRY_ASSERT (meta_opm.op.data.meta.data_1 == VM_IDX_REWRITE_LITERAL_UID);
JERRY_ASSERT (meta_opm.lit_id[1].packed_value != NOT_A_LITERAL.packed_value);
bool is_replaced = dumper_try_replace_identifier_name_with_reg (fe_scope_tree, &meta_opm);
JERRY_ASSERT (is_replaced);
}
scopes_tree_remove_op_meta (fe_scope_tree, instr_pos);
reg_var_decl_oc--;
scope_code_flags_oc--;
dumper_decrement_function_end_pos ();
}
}
}
}
}
@@ -3114,7 +3250,8 @@ parse_source_element_list (bool is_global, /**< flag, indicating that we parsing
(void) is_try_replace_local_vars_with_regs;
#endif /* !CONFIG_PARSER_ENABLE_PARSE_TIME_BYTE_CODE_OPTIMIZER */
rewrite_reg_var_decl ();
rewrite_scope_code_flags (scope_code_flags_oc, scope_flags);
rewrite_reg_var_decl (reg_var_decl_oc);
dumper_finish_scope ();
} /* parse_source_element_list */