"""Optimizes and analyzes CFG-IR."""

import modelverse_jit.cfg_ir as cfg_ir

def get_directly_reachable_blocks(block):
    """Gets the set of all blocks that can be reached by taking a single branch from the
       given block."""
    return [branch.block for branch in block.flow.branches()]

def get_reachable_blocks(entry_point):
    """Constructs the set of all reachable vertices from the given block."""
    # This is a simple O(n^2) algorithm. Maybe a faster algorithm is more appropriate here.
    def __add_block_children(block, results):
        for child in get_directly_reachable_blocks(block):
            if child not in results:
                results.add(child)
                __add_block_children(child, results)

        return results

    return __add_block_children(entry_point, set())

def get_all_reachable_blocks(entry_point):
    """Constructs the set of all reachable vertices, for every block that is
       reachable from the given entry point."""
    # This is a simple O(n^3) algorithm. Maybe a faster algorithm is more appropriate here.
    results = {}
    all_blocks = get_reachable_blocks(entry_point)
    results[entry_point] = all_blocks
    for block in all_blocks:
        if block not in results:
            results[block] = get_reachable_blocks(block)
    return results