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OSACA/osaca/semantics/arch_semantics.py
2020-07-23 15:54:54 +02:00

421 lines
20 KiB
Python
Executable File

#!/usr/bin/env python3
"""Semantics opbject responsible for architecture specific semantic operations"""
import warnings
from functools import reduce
from itertools import chain
from operator import itemgetter
from .hw_model import MachineModel
from .isa_semantics import INSTR_FLAGS, ISASemantics
class ArchSemantics(ISASemantics):
GAS_SUFFIXES = 'bswlqt'
def __init__(self, machine_model: MachineModel, path_to_yaml=None):
super().__init__(machine_model.get_ISA().lower(), path_to_yaml=path_to_yaml)
self._machine_model = machine_model
self._isa = machine_model.get_ISA().lower()
# SUMMARY FUNCTION
def add_semantics(self, kernel):
"""
Applies performance data (throughput, latency, port pressure) and source/destination
distribution to each instruction of a given kernel.
:param list kernel: kernel to apply semantics
"""
for instruction_form in kernel:
self.assign_src_dst(instruction_form)
self.assign_tp_lt(instruction_form)
if self._machine_model.has_hidden_loads():
self.set_hidden_loads(kernel)
def assign_optimal_throughput(self, kernel):
"""
Assign optimal throughput port pressure to a kernel. This is done in steps of ``0.01cy``.
:param list kernel: kernel to apply optimal port utilization
"""
INC = 0.01
kernel.reverse()
port_list = self._machine_model.get_ports()
for instruction_form in kernel:
for uop in instruction_form['port_uops']:
cycles = uop[0]
ports = list(uop[1])
indices = [port_list.index(p) for p in ports]
# check if port sum of used ports for uop are unbalanced
port_sums = self._to_list(itemgetter(*indices)(self.get_throughput_sum(kernel)))
instr_ports = self._to_list(
itemgetter(*indices)(instruction_form['port_pressure'])
)
if len(set(port_sums)) > 1:
# balance ports
# init list for keeping track of the current change
differences = [cycles / len(ports) for p in ports]
for _ in range(int(cycles * (1 / INC))):
max_port_idx = port_sums.index(max(port_sums))
min_port_idx = port_sums.index(min(port_sums))
instr_ports[max_port_idx] -= INC
instr_ports[min_port_idx] += INC
differences[max_port_idx] -= INC
differences[min_port_idx] += INC
# instr_ports = [round(p, 2) for p in instr_ports]
self._itemsetter(*indices)(instruction_form['port_pressure'], *instr_ports)
# check if min port is zero
if round(min(instr_ports), 2) <= 0:
# if port_pressure is not exactly 0.00, add the residual to
# the former port
if min(instr_ports) != 0.0:
min_port_idx = port_sums.index(min(port_sums))
instr_ports[min_port_idx] += min(instr_ports)
differences[min_port_idx] += min(instr_ports)
# we don't need to decrease difference for other port, just
# delete it
del differences[instr_ports.index(min(instr_ports))]
self._itemsetter(*indices)(
instruction_form['port_pressure'], *instr_ports
)
zero_index = [
p
for p in indices
if round(instruction_form['port_pressure'][p], 2) == 0
][0]
instruction_form['port_pressure'][zero_index] = 0.0
# Remove from further balancing
indices = [
p for p in indices if instruction_form['port_pressure'][p] > 0
]
instr_ports = self._to_list(
itemgetter(*indices)(instruction_form['port_pressure'])
)
# never remove more than the fixed utilization per uop and port, i.e.,
# cycles/len(ports)
if round(min(differences), 2) <= 0:
# don't worry if port_pressure isn't exactly 0 and just
# remove from further balancing
indices = [p for p in indices if differences[indices.index(p)] > 0]
instr_ports = self._to_list(
itemgetter(*indices)(instruction_form['port_pressure'])
)
del differences[differences.index(min(differences))]
port_sums = self._to_list(
itemgetter(*indices)(self.get_throughput_sum(kernel))
)
kernel.reverse()
def set_hidden_loads(self, kernel):
"""Hide loads behind stores if architecture supports hidden loads (depricated)"""
loads = [instr for instr in kernel if INSTR_FLAGS.HAS_LD in instr['flags']]
stores = [instr for instr in kernel if INSTR_FLAGS.HAS_ST in instr['flags']]
# Filter instructions including load and store
load_ids = [instr['line_number'] for instr in loads]
store_ids = [instr['line_number'] for instr in stores]
shared_ldst = list(set(load_ids).intersection(set(store_ids)))
loads = [instr for instr in loads if instr['line_number'] not in shared_ldst]
stores = [instr for instr in stores if instr['line_number'] not in shared_ldst]
if len(stores) == 0 or len(loads) == 0:
# nothing to do
return
if len(loads) <= len(stores):
# Hide all loads
for load in loads:
load['flags'] += [INSTR_FLAGS.HIDDEN_LD]
load['port_pressure'] = self._nullify_data_ports(load['port_pressure'])
else:
for store in stores:
# Get 'closest' load instruction
min_distance_load = min(
[
(
abs(load_instr['line_number'] - store['line_number']),
load_instr['line_number'],
)
for load_instr in loads
if INSTR_FLAGS.HIDDEN_LD not in load_instr['flags']
]
)
load = [instr for instr in kernel if instr['line_number'] == min_distance_load[1]][
0
]
# Hide load
load['flags'] += [INSTR_FLAGS.HIDDEN_LD]
load['port_pressure'] = self._nullify_data_ports(load['port_pressure'])
# get parser result and assign throughput and latency value to instruction form
# mark instruction form with semantic flags
def assign_tp_lt(self, instruction_form):
"""Assign throughput and latency to an instruction form."""
flags = []
port_number = len(self._machine_model['ports'])
if instruction_form['instruction'] is None:
# No instruction (label, comment, ...) --> ignore
throughput = 0.0
latency = 0.0
latency_wo_load = latency
instruction_form['port_pressure'] = [0.0 for i in range(port_number)]
instruction_form['port_uops'] = []
else:
instruction_data = self._machine_model.get_instruction(
instruction_form['instruction'], instruction_form['operands']
)
if (
not instruction_data
and self._isa == 'x86'
and instruction_form['instruction'][-1] in self.GAS_SUFFIXES
):
# check for instruction without GAS suffix
instruction_data = self._machine_model.get_instruction(
instruction_form['instruction'][:-1], instruction_form['operands']
)
if instruction_data:
# instruction form in DB
(
throughput,
port_pressure,
latency,
latency_wo_load,
) = self._handle_instruction_found(
instruction_data, port_number, instruction_form, flags
)
else:
# instruction could not be found in DB
assign_unknown = True
# check for equivalent register-operands DB entry if LD
if (
INSTR_FLAGS.HAS_LD in instruction_form['flags']
or INSTR_FLAGS.HAS_ST in instruction_form['flags']
):
# dynamically combine LD/ST and reg form of instruction form
# substitute mem and look for reg-only variant
operands = self.substitute_mem_address(instruction_form['operands'])
instruction_data_reg = self._machine_model.get_instruction(
instruction_form['instruction'], operands
)
if (
not instruction_data_reg
and self._isa == 'x86'
and instruction_form['instruction'][-1] in self.GAS_SUFFIXES
):
# check for instruction without GAS suffix
instruction_data_reg = self._machine_model.get_instruction(
instruction_form['instruction'][:-1], operands
)
if instruction_data_reg:
assign_unknown = False
reg_type = self._parser.get_reg_type(
instruction_data_reg['operands'][
operands.index(self._create_reg_wildcard())
]
)
data_port_pressure = [0.0 for _ in range(port_number)]
data_port_uops = []
if INSTR_FLAGS.HAS_LD in instruction_form['flags']:
# LOAD performance data
data_port_uops = self._machine_model.get_load_throughput(
[
x['memory']
for x in instruction_form['semantic_operands']['source']
+ instruction_form['semantic_operands']['src_dst']
if 'memory' in x
][0]
)
data_port_pressure = self._machine_model.average_port_pressure(
data_port_uops
)
if 'load_throughput_multiplier' in self._machine_model:
multiplier = self._machine_model['load_throughput_multiplier'][
reg_type
]
data_port_pressure = [pp * multiplier for pp in data_port_pressure]
if INSTR_FLAGS.HAS_ST in instruction_form['flags']:
# STORE performance data
destinations = (
instruction_form['semantic_operands']['destination']
+ instruction_form['semantic_operands']['src_dst']
)
st_data_port_uops = self._machine_model.get_store_throughput(
[x['memory'] for x in destinations if 'memory' in x][0]
)
# zero data port pressure and remove HAS_ST flag if
# - no mem operand in dst &&
# - all mem operands in src_dst are pre-/post-indexed
# since it is no mem store
if (
self._isa == 'aarch64'
and 'memory'
not in instruction_form['semantic_operands']['destination']
and all(
[
'post_indexed' in op['memory']
or 'pre_indexed' in op['memory']
for op in instruction_form['semantic_operands']['src_dst']
if 'memory' in op
]
)
):
st_data_port_uops = []
instruction_form['flags'].remove(INSTR_FLAGS.HAS_ST)
# sum up all data ports in case for LOAD and STORE
st_data_port_pressure = self._machine_model.average_port_pressure(
st_data_port_uops
)
data_port_pressure = [
sum(x) for x in zip(data_port_pressure, st_data_port_pressure)
]
data_port_uops += st_data_port_uops
throughput = max(
max(data_port_pressure), instruction_data_reg['throughput']
)
latency = instruction_data_reg['latency']
# Add LD and ST latency
latency += (
self._machine_model.get_load_latency(reg_type)
if INSTR_FLAGS.HAS_LD in instruction_form['flags']
else 0
)
latency += (
self._machine_model.get_store_latency(reg_type)
if INSTR_FLAGS.HAS_ST in instruction_form['flags']
else 0
)
latency_wo_load = instruction_data_reg['latency']
# add latency of ADD if post- or pre-indexed load
# TODO more investigation: check dot-graph, wrong latency distribution!
# if (
# latency_wo_load == 0
# and self._isa == 'aarch64'
# and any(
# [
# 'post_indexed' in op['memory'] or 'pre_indexed' in op['memory']
# for op in instruction_form['operands']
# if 'memory' in op
# ]
# )
# ):
# latency_wo_load = 1.0
instruction_form['port_pressure'] = [
sum(x)
for x in zip(
data_port_pressure,
self._machine_model.average_port_pressure(
instruction_data_reg['port_pressure']
),
)
]
instruction_form['port_uops'] = list(
chain(instruction_data_reg['port_pressure'], data_port_uops)
)
if assign_unknown:
# --> mark as unknown and assume 0 cy for latency/throughput
throughput = 0.0
latency = 0.0
latency_wo_load = latency
instruction_form['port_pressure'] = [0.0 for i in range(port_number)]
instruction_form['port_uops'] = []
flags += [INSTR_FLAGS.TP_UNKWN, INSTR_FLAGS.LT_UNKWN]
# flatten flag list
flags = list(set(flags))
if 'flags' not in instruction_form:
instruction_form['flags'] = flags
else:
instruction_form['flags'] += flags
instruction_form['throughput'] = throughput
instruction_form['latency'] = latency
instruction_form['latency_wo_load'] = latency_wo_load
# for later CP and loop-carried dependency analysis
instruction_form['latency_cp'] = 0
instruction_form['latency_lcd'] = 0
def _handle_instruction_found(self, instruction_data, port_number, instruction_form, flags):
"""Apply performance data to instruction if it was found in the archDB"""
throughput = instruction_data['throughput']
port_pressure = self._machine_model.average_port_pressure(
instruction_data['port_pressure']
)
instruction_form['port_uops'] = instruction_data['port_pressure']
try:
assert isinstance(port_pressure, list)
assert len(port_pressure) == port_number
instruction_form['port_pressure'] = port_pressure
if sum(port_pressure) == 0 and throughput is not None:
# port pressure on all ports 0 --> not bound to a port
flags.append(INSTR_FLAGS.NOT_BOUND)
except AssertionError:
warnings.warn(
'Port pressure could not be imported correctly from database. '
+ 'Please check entry for:\n {}'.format(instruction_form)
)
instruction_form['port_pressure'] = [0.0 for i in range(port_number)]
instruction_form['port_uops'] = []
flags.append(INSTR_FLAGS.TP_UNKWN)
if throughput is None:
# assume 0 cy and mark as unknown
throughput = 0.0
flags.append(INSTR_FLAGS.TP_UNKWN)
latency = instruction_data['latency']
latency_wo_load = latency
if latency is None:
# assume 0 cy and mark as unknown
latency = 0.0
latency_wo_load = latency
flags.append(INSTR_FLAGS.LT_UNKWN)
if INSTR_FLAGS.HAS_LD in instruction_form['flags']:
flags.append(INSTR_FLAGS.LD)
return throughput, port_pressure, latency, latency_wo_load
def convert_op_to_reg(self, reg_type, reg_id='0'):
"""Create register operand for a memory addressing operand"""
if self._isa == 'x86':
if reg_type == 'gpr':
register = {'register': {'name': 'r' + str(int(reg_id) + 9)}}
else:
register = {'register': {'name': reg_type + reg_id}}
elif self._isa == 'aarch64':
register = {'register': {'prefix': reg_type, 'name': reg_id}}
return register
def _nullify_data_ports(self, port_pressure):
"""Set all ports to 0.0 for the ports of a machine model"""
data_ports = self._machine_model.get_data_ports()
for port in data_ports:
index = self._machine_model.get_ports().index(port)
port_pressure[index] = 0.0
return port_pressure
def _itemsetter(self, *items):
if len(items) == 1:
item = items[0]
def g(obj, value):
obj[item] = value
else:
def g(obj, *values):
for item, value in zip(items, values):
obj[item] = value
return g
def _to_list(self, obj):
if isinstance(obj, tuple):
return list(obj)
else:
return [obj]
@staticmethod
def get_throughput_sum(kernel):
"""Get the overall throughput sum separated by port of all instructions of a kernel."""
tp_sum = reduce(
(lambda x, y: [sum(z) for z in zip(x, y)]),
[instr['port_pressure'] for instr in kernel],
)
tp_sum = [round(x, 2) for x in tp_sum]
return tp_sum