#!/usr/bin/env python3 import copy import networkx as nx from itertools import chain, product from osaca.parser import AttrDict from osaca.semantics import MachineModel class KernelDG(nx.DiGraph): def __init__(self, parsed_kernel, parser, hw_model: MachineModel): self.kernel = parsed_kernel self.parser = parser self.model = hw_model self.dg = self.create_DG(self.kernel) self.loopcarried_deps = self.check_for_loopcarried_dep(self.kernel) def check_for_loopcarried_dep(self, kernel): multiplier = len(kernel) + 1 # increase line number for second kernel loop kernel_length = len(kernel) first_line_no = kernel[0].line_number kernel_copy = [AttrDict.convert_dict(d) for d in copy.deepcopy(kernel)] tmp_kernel = kernel + kernel_copy for i, instruction_form in enumerate(tmp_kernel[kernel_length:]): tmp_kernel[i + kernel_length].line_number = instruction_form.line_number * multiplier # get dependency graph dg = self.create_DG(tmp_kernel) # build cyclic loop-carried dependencies loopcarried_deps = [ (node, list(nx.algorithms.simple_paths.all_simple_paths(dg, node, node * multiplier))) for node in dg.nodes if node < first_line_no * multiplier ] # filter others and create graph loopcarried_deps = list( chain.from_iterable( [list(product([dep_chain[0]], dep_chain[1])) for dep_chain in loopcarried_deps] ) ) # adjust line numbers # and add reference to kernel again for i, dep in enumerate(loopcarried_deps): nodes = [int(n / multiplier) for n in dep[1] if n >= first_line_no * multiplier] nodes = [self._get_node_by_lineno(x) for x in nodes] loopcarried_deps[i] = (self._get_node_by_lineno(dep[0]), nodes) return loopcarried_deps def _get_node_by_lineno(self, lineno): return [instr for instr in self.kernel if instr.line_number == lineno][0] def create_DG(self, kernel): # 1. go through kernel instruction forms (as vertices) # 2. find edges (to dependend further instruction) # 3. get LT value and set as edge weight # 4. add instr forms as node attribute dg = nx.DiGraph() for i, instruction_form in enumerate(kernel): dg.add_node(instruction_form['line_number']) for dep in self.find_depending(instruction_form, kernel[i + 1:]): dg.add_edge( instruction_form['line_number'], dep['line_number'], latency=instruction_form['latency'], ) dg.nodes[instruction_form['line_number']]['instruction_form'] = instruction_form dg.nodes[dep['line_number']]['instruction_form'] = dep return dg def get_critical_path(self): if nx.algorithms.dag.is_directed_acyclic_graph(self.dg): longest_path = nx.algorithms.dag.dag_longest_path(self.dg, weight='latency') return [x for x in self.kernel if x['line_number'] in longest_path] else: # split to DAG raise NotImplementedError('Kernel is cyclic.') def get_loopcarried_dependencies(self): if nx.algorithms.dag.is_directed_acyclic_graph(self.dg): return self.loopcarried_deps else: # split to DAG raise NotImplementedError('Kernel is cyclic.') def find_depending(self, instruction_form, kernel, include_write=False): if instruction_form.operands is None: return for dst in instruction_form.operands.destination + instruction_form.operands.src_dst: if 'register' in dst: # Check for read of register until overwrite for instr_form in kernel: if self.is_read(dst.register, instr_form): yield instr_form if self.is_written(dst.register, instr_form): # operand in src_dst list if include_write: yield instr_form break elif self.is_written(dst.register, instr_form): if include_write: yield instr_form break elif 'memory' in dst: # Check if base register is altered during memory access if 'pre_indexed' in dst.memory or 'post_indexed' in dst.memory: # Check for read of base register until overwrite for instr_form in kernel: if self.is_read(dst.memory.base, instr_form): yield instr_form if self.is_written(dst.memory.base, instr_form): # operand in src_dst list if include_write: yield instr_form break elif self.is_written(dst.memory.base, instr_form): if include_write: yield instr_form break def get_dependent_instruction_forms(self, instr_form=None, line_number=None): """ Returns iterator """ if not instr_form and not line_number: raise ValueError('Either instruction form or line_number required.') line_number = line_number if line_number else instr_form['line_number'] if self.dg.has_node(line_number): return self.dg.successors(line_number) return iter([]) def is_read(self, register, instruction_form): is_read = False if instruction_form.operands is None: return is_read for src in instruction_form.operands.source + instruction_form.operands.src_dst: if 'register' in src: is_read = self.parser.is_reg_dependend_of(register, src.register) or is_read if 'memory' in src: if src.memory.base is not None: is_read = self.parser.is_reg_dependend_of(register, src.memory.base) or is_read if src.memory.index is not None: is_read = ( self.parser.is_reg_dependend_of(register, src.memory.index) or is_read ) # Check also if read in destination memory address for dst in instruction_form.operands.destination + instruction_form.operands.src_dst: if 'memory' in dst: if dst.memory.base is not None: is_read = self.parser.is_reg_dependend_of(register, dst.memory.base) or is_read if dst.memory.index is not None: is_read = ( self.parser.is_reg_dependend_of(register, dst.memory.index) or is_read ) return is_read def is_written(self, register, instruction_form): is_written = False if instruction_form.operands is None: return is_written for dst in instruction_form.operands.destination + instruction_form.operands.src_dst: if 'register' in dst: is_written = self.parser.is_reg_dependend_of(register, dst.register) or is_written if 'memory' in dst: if 'pre_indexed' in dst.memory or 'post_indexed' in dst.memory: is_written = ( self.parser.is_reg_dependend_of(register, dst.memory.base) or is_written ) # Check also for possible pre- or post-indexing in memory addresses for src in instruction_form.operands.source + instruction_form.operands.src_dst: if 'memory' in src: if 'pre_indexed' in src.memory or 'post_indexed' in src.memory: is_written = ( self.parser.is_reg_dependend_of(register, src.memory.base) or is_written ) return is_written