GCC Middle and Back End API Reference
ccp_propagate Class Reference
Inheritance diagram for ccp_propagate:
Collaboration diagram for ccp_propagate:

Public Member Functions

enum ssa_prop_result visit_stmt (gimple *, edge *, tree *) final override
 
enum ssa_prop_result visit_phi (gphi *) final override
 
void ssa_propagate (void)
 

Private Member Functions

void simulate_stmt (gimple *stmt)
 
void simulate_block (basic_block)
 

Member Function Documentation

◆ simulate_block()

void ssa_propagation_engine::simulate_block ( basic_block block)
privateinherited
Simulate the execution of BLOCK.  Evaluate the statement associated
with each variable reference inside the block.   

References add_control_edge(), BB_VISITED, cfun, dump_file, dump_flags, EXIT_BLOCK_PTR_FOR_FN, basic_block_def::flags, FOR_EACH_EDGE, gsi_end_p(), gsi_next(), gsi_start_bb(), gsi_start_phis(), gsi_stmt(), basic_block_def::index, NULL, simulate_stmt(), basic_block_def::succs, and TDF_DETAILS.

Referenced by ssa_propagate().

◆ simulate_stmt()

◆ ssa_propagate()

void ssa_propagation_engine::ssa_propagate ( void )
inherited
Entry point to the propagation engine.

The VISIT_STMT virtual function is called for every statement
visited and the VISIT_PHI virtual function is called for every PHI
node visited.   

References add_control_edge(), BASIC_BLOCK_FOR_FN, bb_to_cfg_order, bitmap_clear_bit(), bitmap_empty_p(), bitmap_first_set_bit(), cfg_blocks, cfg_order_to_bb, cfun, curr_order, dump_file, dump_flags, ENTRY_BLOCK_PTR_FOR_FN, FOR_EACH_EDGE, gimple_bb(), basic_block_def::index, NULL, print_gimple_stmt(), simulate_block(), simulate_stmt(), ssa_edge_worklist, ssa_prop_fini(), ssa_prop_init(), TDF_DETAILS, and uid_to_stmt.

Referenced by do_ssa_ccp(), execute_copy_prop(), and tree_lower_complex().

◆ visit_phi()

enum ssa_prop_result ccp_propagate::visit_phi ( gphi * phi)
finaloverridevirtual
Loop through the PHI_NODE's parameters for BLOCK and compare their
lattice values to determine PHI_NODE's lattice value.  The value of a
PHI node is determined calling ccp_lattice_meet with all the arguments
of the PHI node that are incoming via executable edges.   

Implements ssa_propagation_engine.

References ccp_lattice_meet(), CDI_DOMINATORS, CONSTANT, dominated_by_p(), dump_file, dump_flags, dump_lattice_value(), get_value_for_expr(), gimple_bb(), gimple_phi_arg(), gimple_phi_arg_edge(), gimple_phi_num_args(), gimple_phi_result(), i, ccp_prop_value_t::lattice_val, ccp_prop_value_t::mask, NULL_TREE, print_generic_expr(), print_gimple_stmt(), set_lattice_value(), SSA_NAME_DEF_STMT, SSA_NAME_IS_DEFAULT_DEF, SSA_PROP_INTERESTING, SSA_PROP_NOT_INTERESTING, SSA_PROP_VARYING, TDF_DETAILS, TREE_CODE, UNDEFINED, ccp_prop_value_t::value, and VARYING.

◆ visit_stmt()

enum ssa_prop_result ccp_propagate::visit_stmt ( gimple * stmt,
edge * taken_edge_p,
tree * output_p )
finaloverridevirtual
Evaluate statement STMT.  If the statement produces an output value and
its evaluation changes the lattice value of its output, return
SSA_PROP_INTERESTING and set *OUTPUT_P to the SSA_NAME holding the
output value.

If STMT is a conditional branch and we can determine its truth
value, set *TAKEN_EDGE_P accordingly.  If STMT produces a varying
value, return SSA_PROP_VARYING.   

Implements ssa_propagation_engine.

References dump_file, dump_flags, FOR_EACH_SSA_TREE_OPERAND, gimple_call_lhs(), NULL_TREE, print_gimple_stmt(), set_value_varying(), SSA_OP_ALL_DEFS, SSA_PROP_VARYING, TDF_DETAILS, visit_assignment(), and visit_cond_stmt().


The documentation for this class was generated from the following file: