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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/opcodes-dumper.cpp
+177 -95
View File
@@ -42,10 +42,24 @@ static vm_idx_t jsp_reg_max_for_temps;
* so the value, if not equal to VM_IDX_EMPTY, is always greater than jsp_reg_max_for_temps.
*
* See also:
* dumper_try_replace_var_with_reg
* dumper_try_replace_identifier_name_with_reg
*/
static vm_idx_t jsp_reg_max_for_local_var;
/**
* Maximum identifier of a register, allocated for storage of an argument value.
*
* The value can be VM_IDX_EMPTY, indicating that no registers were allocated for argument values.
*
* Note:
* Registers for argument values are always allocated after registers for variable values,
* so the value, if not equal to VM_IDX_EMPTY, is always greater than jsp_reg_max_for_local_var.
*
* See also:
* dumper_try_replace_identifier_name_with_reg
*/
static vm_idx_t jsp_reg_max_for_args;
enum
{
U8_global_size
@@ -130,12 +144,6 @@ enum
};
STATIC_STACK (jsp_reg_id_stack, vm_idx_t)
enum
{
reg_var_decls_global_size
};
STATIC_STACK (reg_var_decls, vm_instr_counter_t)
/**
* Allocate next register for intermediate value
*
@@ -145,6 +153,7 @@ static vm_idx_t
jsp_alloc_reg_for_temp (void)
{
JERRY_ASSERT (jsp_reg_max_for_local_var == VM_IDX_EMPTY);
JERRY_ASSERT (jsp_reg_max_for_args == VM_IDX_EMPTY);
vm_idx_t next_reg = jsp_reg_next++;
@@ -166,6 +175,51 @@ jsp_alloc_reg_for_temp (void)
} /* jsp_alloc_reg_for_temp */
#ifdef CONFIG_PARSER_ENABLE_PARSE_TIME_BYTE_CODE_OPTIMIZER
/**
* Start move of variable values to registers optimization pass
*/
void
dumper_start_move_of_vars_to_regs ()
{
JERRY_ASSERT (jsp_reg_max_for_local_var == VM_IDX_EMPTY);
JERRY_ASSERT (jsp_reg_max_for_args == VM_IDX_EMPTY);
jsp_reg_max_for_local_var = jsp_reg_max_for_temps;
} /* dumper_start_move_of_vars_to_regs */
/**
* Start move of argument values to registers optimization pass
*
* @return true - if optimization can be performed successfully (i.e. there are enough free registers),
* false - otherwise.
*/
bool
dumper_start_move_of_args_to_regs (uint32_t args_num) /**< number of arguments */
{
JERRY_ASSERT (jsp_reg_max_for_args == VM_IDX_EMPTY);
if (jsp_reg_max_for_local_var == VM_IDX_EMPTY)
{
if (args_num + jsp_reg_max_for_temps >= VM_REG_GENERAL_LAST)
{
return false;
}
jsp_reg_max_for_args = jsp_reg_max_for_temps;
}
else
{
if (args_num + jsp_reg_max_for_local_var >= VM_REG_GENERAL_LAST)
{
return false;
}
jsp_reg_max_for_args = jsp_reg_max_for_local_var;
}
return true;
} /* dumper_start_move_of_args_to_regs */
/**
* Try to move local variable to a register
*
@@ -183,72 +237,63 @@ jsp_alloc_reg_for_temp (void)
* false - otherwise.
*/
bool
dumper_try_replace_var_with_reg (scopes_tree tree, /**< a function scope, created for
* function declaration or function expresssion */
op_meta *var_decl_om_p) /**< operation meta of corresponding variable declaration */
dumper_try_replace_identifier_name_with_reg (scopes_tree tree, /**< a function scope, created for
* function declaration or function expresssion */
op_meta *om_p) /**< operation meta of corresponding
* variable declaration */
{
JERRY_ASSERT (tree->type == SCOPE_TYPE_FUNCTION);
JERRY_ASSERT (var_decl_om_p->op.op_idx == VM_OP_VAR_DECL);
JERRY_ASSERT (var_decl_om_p->lit_id[0].packed_value != NOT_A_LITERAL.packed_value);
JERRY_ASSERT (var_decl_om_p->lit_id[1].packed_value == NOT_A_LITERAL.packed_value);
JERRY_ASSERT (var_decl_om_p->lit_id[2].packed_value == NOT_A_LITERAL.packed_value);
lit_cpointer_t lit_cp;
bool is_arg;
vm_instr_counter_t instr_pos = 0;
op_meta header_opm = scopes_tree_op_meta (tree, instr_pos++);
JERRY_ASSERT (header_opm.op.op_idx == VM_OP_FUNC_EXPR_N || header_opm.op.op_idx == VM_OP_FUNC_DECL_N);
while (true)
if (om_p->op.op_idx == VM_OP_VAR_DECL)
{
op_meta meta_opm = scopes_tree_op_meta (tree, instr_pos++);
JERRY_ASSERT (meta_opm.op.op_idx == VM_OP_META);
JERRY_ASSERT (om_p->lit_id[0].packed_value != NOT_A_LITERAL.packed_value);
JERRY_ASSERT (om_p->lit_id[1].packed_value == NOT_A_LITERAL.packed_value);
JERRY_ASSERT (om_p->lit_id[2].packed_value == NOT_A_LITERAL.packed_value);
opcode_meta_type meta_type = (opcode_meta_type) meta_opm.op.data.meta.type;
lit_cp = om_p->lit_id[0];
if (meta_type == OPCODE_META_TYPE_FUNCTION_END)
is_arg = false;
}
else
{
JERRY_ASSERT (om_p->op.op_idx == VM_OP_META);
JERRY_ASSERT (om_p->op.data.meta.type == OPCODE_META_TYPE_VARG);
JERRY_ASSERT (om_p->lit_id[0].packed_value == NOT_A_LITERAL.packed_value);
JERRY_ASSERT (om_p->lit_id[1].packed_value != NOT_A_LITERAL.packed_value);
JERRY_ASSERT (om_p->lit_id[2].packed_value == NOT_A_LITERAL.packed_value);
lit_cp = om_p->lit_id[1];
is_arg = true;
}
vm_idx_t reg;
if (is_arg)
{
JERRY_ASSERT (jsp_reg_max_for_args != VM_IDX_EMPTY);
JERRY_ASSERT (jsp_reg_max_for_args < VM_REG_GENERAL_LAST);
reg = ++jsp_reg_max_for_args;
}
else
{
JERRY_ASSERT (jsp_reg_max_for_local_var != VM_IDX_EMPTY);
if (jsp_reg_max_for_local_var == VM_REG_GENERAL_LAST)
{
/* marker of function argument list end reached */
break;
/* not enough registers */
return false;
}
else
{
JERRY_ASSERT (meta_type == OPCODE_META_TYPE_VARG);
JERRY_ASSERT (jsp_reg_max_for_local_var < VM_REG_GENERAL_LAST);
/* 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);
if (meta_opm.lit_id[1].packed_value == var_decl_om_p->lit_id[0].packed_value)
{
/*
* Optimization is not performed, because the variable's name is equal to an argument name,
* and the argument's value would be initialized by its name in run-time.
*
* See also:
* parser_parse_program
*/
return false;
}
}
reg = ++jsp_reg_max_for_local_var;
}
if (jsp_reg_max_for_local_var == VM_IDX_EMPTY)
{
jsp_reg_max_for_local_var = jsp_reg_max_for_temps;
}
if (jsp_reg_max_for_local_var == VM_REG_GENERAL_LAST)
{
/* not enough registers */
return false;
}
JERRY_ASSERT (jsp_reg_max_for_local_var < VM_REG_GENERAL_LAST);
vm_idx_t reg = ++jsp_reg_max_for_local_var;
lit_cpointer_t lit_cp = var_decl_om_p->lit_id[0];
for (vm_instr_counter_t instr_pos = 0;
instr_pos < tree->instrs_count;
instr_pos++)
@@ -320,9 +365,21 @@ dumper_try_replace_var_with_reg (scopes_tree tree, /**< a function scope, create
}
return true;
} /* dumper_try_replace_var_with_reg */
} /* dumper_try_replace_identifier_name_with_reg */
#endif /* CONFIG_PARSER_ENABLE_PARSE_TIME_BYTE_CODE_OPTIMIZER */
/**
* Just allocate register for argument that is never used due to duplicated argument names
*/
void
dumper_alloc_reg_for_unused_arg (void)
{
JERRY_ASSERT (jsp_reg_max_for_args != VM_IDX_EMPTY);
JERRY_ASSERT (jsp_reg_max_for_args < VM_REG_GENERAL_LAST);
++jsp_reg_max_for_args;
} /* dumper_alloc_reg_for_unused_arg */
/**
* Generate instruction with specified opcode and operands
*
@@ -650,6 +707,7 @@ void
dumper_new_scope (void)
{
JERRY_ASSERT (jsp_reg_max_for_local_var == VM_IDX_EMPTY);
JERRY_ASSERT (jsp_reg_max_for_args == VM_IDX_EMPTY);
STACK_PUSH (jsp_reg_id_stack, jsp_reg_next);
STACK_PUSH (jsp_reg_id_stack, jsp_reg_max_for_temps);
@@ -662,6 +720,7 @@ void
dumper_finish_scope (void)
{
JERRY_ASSERT (jsp_reg_max_for_local_var == VM_IDX_EMPTY);
JERRY_ASSERT (jsp_reg_max_for_args == VM_IDX_EMPTY);
jsp_reg_max_for_temps = STACK_TOP (jsp_reg_id_stack);
STACK_DROP (jsp_reg_id_stack, 1);
@@ -1182,6 +1241,23 @@ rewrite_function_end ()
STACK_DROP (function_ends, 1);
}
/**
* Decrement position of 'function_end' instruction (the position is stored in "function_ends" stack)
*
* Note:
* The operation is used upon deleting a 'varg' meta, describing element of a function's formal parameters list
*/
void
dumper_decrement_function_end_pos (void)
{
vm_instr_counter_t oc = STACK_TOP (function_ends);
oc--;
STACK_DROP (function_ends, 1);
STACK_PUSH (function_ends, oc);
} /* dumper_decrement_function_end_pos */
jsp_operand_t
dump_this_res (void)
{
@@ -2308,27 +2384,6 @@ dump_throw (jsp_operand_t op)
dump_single_address (VM_OP_THROW_VALUE, op);
}
/**
* Checks if variable is already declared
*
* @return true if variable declaration already exists
* false otherwise
*/
bool
dumper_variable_declaration_exists (lit_cpointer_t lit_id) /**< literal which holds variable's name */
{
vm_instr_counter_t var_decls_count = (vm_instr_counter_t) serializer_get_current_var_decls_counter ();
for (vm_instr_counter_t oc = (vm_instr_counter_t) (0); oc < var_decls_count; oc++)
{
const op_meta var_decl_op_meta = serializer_get_var_decl (oc);
if (var_decl_op_meta.lit_id[0].packed_value == lit_id.packed_value)
{
return true;
}
}
return false;
} /* dumper_variable_declaration_exists */
/**
* Dump instruction designating variable declaration
*/
@@ -2386,20 +2441,30 @@ dump_ret (void)
serializer_dump_op_meta (jsp_dmp_create_op_meta_0 (VM_OP_RET));
}
void
/**
* Dump 'reg_var_decl' instruction template
*
* @return position of the dumped instruction
*/
vm_instr_counter_t
dump_reg_var_decl_for_rewrite (void)
{
STACK_PUSH (reg_var_decls, serializer_get_current_instr_counter ());
dump_double_address (VM_OP_REG_VAR_DECL,
vm_instr_counter_t oc = serializer_get_current_instr_counter ();
dump_triple_address (VM_OP_REG_VAR_DECL,
jsp_operand_t::make_unknown_operand (),
jsp_operand_t::make_unknown_operand (),
jsp_operand_t::make_unknown_operand ());
}
return oc;
} /* dump_reg_var_decl_for_rewrite */
/**
* Rewrite 'reg_var_decl' instruction's template with current scope's register counts
*/
void
rewrite_reg_var_decl (void)
rewrite_reg_var_decl (vm_instr_counter_t reg_var_decl_oc) /**< position of dumped 'reg_var_decl' template */
{
vm_instr_counter_t reg_var_decl_oc = STACK_TOP (reg_var_decls);
op_meta opm = serializer_get_op_meta (reg_var_decl_oc);
JERRY_ASSERT (opm.op.op_idx == VM_OP_REG_VAR_DECL);
@@ -2417,10 +2482,28 @@ rewrite_reg_var_decl (void)
opm.op.data.reg_var_decl.local_var_regs_num = 0;
}
serializer_rewrite_op_meta (reg_var_decl_oc, opm);
if (jsp_reg_max_for_args != VM_IDX_EMPTY)
{
if (jsp_reg_max_for_local_var != VM_IDX_EMPTY)
{
JERRY_ASSERT (jsp_reg_max_for_args >= jsp_reg_max_for_local_var);
opm.op.data.reg_var_decl.arg_regs_num = (vm_idx_t) (jsp_reg_max_for_args - jsp_reg_max_for_local_var);
}
else
{
JERRY_ASSERT (jsp_reg_max_for_args >= jsp_reg_max_for_temps);
opm.op.data.reg_var_decl.arg_regs_num = (vm_idx_t) (jsp_reg_max_for_args - jsp_reg_max_for_temps);
}
STACK_DROP (reg_var_decls, 1);
}
jsp_reg_max_for_args = VM_IDX_EMPTY;
}
else
{
opm.op.data.reg_var_decl.arg_regs_num = 0;
}
serializer_rewrite_op_meta (reg_var_decl_oc, opm);
} /* rewrite_reg_var_decl */
void
dump_retval (jsp_operand_t op)
@@ -2434,6 +2517,7 @@ dumper_init (void)
jsp_reg_next = VM_REG_GENERAL_FIRST;
jsp_reg_max_for_temps = VM_REG_GENERAL_FIRST;
jsp_reg_max_for_local_var = VM_IDX_EMPTY;
jsp_reg_max_for_args = VM_IDX_EMPTY;
STACK_INIT (U8);
STACK_INIT (varg_headers);
@@ -2449,7 +2533,6 @@ dumper_init (void)
STACK_INIT (finallies);
STACK_INIT (tries);
STACK_INIT (jsp_reg_id_stack);
STACK_INIT (reg_var_decls);
}
void
@@ -2469,5 +2552,4 @@ dumper_free (void)
STACK_FREE (finallies);
STACK_FREE (tries);
STACK_FREE (jsp_reg_id_stack);
STACK_FREE (reg_var_decls);
}