Files
OSACA/osaca/semantics/kernel_dg.py

189 lines
8.3 KiB
Python
Executable File

#!/usr/bin/env python3
import copy
import networkx as nx
from osaca.parser import AttrDict
from .hw_model 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):
# 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 * 10
# get dependency graph
dg = self.create_DG(tmp_kernel)
descendants = [
(x, sorted([x for x in nx.algorithms.dag.descendants(dg, x)]))
for x in range(first_line_no, first_line_no + kernel_length)
if x in dg
]
loopcarried_deps = [
x for x in descendants if len(x[1]) > 0 and x[1][-1] >= first_line_no * 10
]
# adjust line numbers
# and add reference to kernel again
for i, dep in enumerate(loopcarried_deps):
nodes = [int(n / 10) for n in dep[1] if n >= first_line_no * 10]
nodes = [self._get_node_by_lineno(x) for x in nodes]
loopcarried_deps[i] = (self._get_node_by_lineno(dep[0]), nodes)
# check if dependency is cyclic
cyclic_lc_deps = []
for dep in loopcarried_deps:
write_back = list(
self.find_depending(
dep[0],
tmp_kernel[dep[0].line_number - first_line_no + 1:],
include_write=True,
)
)
if (
write_back is not None
and len(write_back) > 0
and int(write_back[-1].line_number / 10) == dep[0].line_number
):
cyclic_lc_deps.append(dep)
return cyclic_lc_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):
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