mirror of https://github.com/m-labs/artiq.git
325 lines
13 KiB
Python
325 lines
13 KiB
Python
"""
|
|
:class:`IODelayEstimator` calculates the amount of time
|
|
elapsed from the point of view of the RTIO core for
|
|
every function.
|
|
"""
|
|
|
|
from pythonparser import ast, algorithm, diagnostic
|
|
from .. import types, iodelay, builtins, asttyped
|
|
|
|
class _UnknownDelay(Exception):
|
|
pass
|
|
|
|
class _IndeterminateDelay(Exception):
|
|
def __init__(self, cause):
|
|
self.cause = cause
|
|
|
|
class IODelayEstimator(algorithm.Visitor):
|
|
def __init__(self, engine, ref_period):
|
|
self.engine = engine
|
|
self.ref_period = ref_period
|
|
self.changed = False
|
|
self.current_delay = iodelay.Const(0)
|
|
self.current_args = None
|
|
self.current_goto = None
|
|
self.current_return = None
|
|
|
|
def evaluate(self, node, abort, context):
|
|
if isinstance(node, asttyped.NumT):
|
|
return iodelay.Const(node.n)
|
|
elif isinstance(node, asttyped.CoerceT):
|
|
return self.evaluate(node.value, abort, context)
|
|
elif isinstance(node, asttyped.NameT):
|
|
if self.current_args is None:
|
|
note = diagnostic.Diagnostic("note",
|
|
"this variable is not an argument", {},
|
|
node.loc)
|
|
abort([note])
|
|
elif node.id in [arg.arg for arg in self.current_args.args]:
|
|
return iodelay.Var(node.id)
|
|
else:
|
|
notes = [
|
|
diagnostic.Diagnostic("note",
|
|
"this variable is not an argument of the innermost function", {},
|
|
node.loc),
|
|
diagnostic.Diagnostic("note",
|
|
"only these arguments are in scope of analysis", {},
|
|
self.current_args.loc)
|
|
]
|
|
abort(notes)
|
|
elif isinstance(node, asttyped.BinOpT):
|
|
lhs = self.evaluate(node.left, abort, context)
|
|
rhs = self.evaluate(node.right, abort, context)
|
|
if isinstance(node.op, ast.Add):
|
|
return lhs + rhs
|
|
elif isinstance(node.op, ast.Sub):
|
|
return lhs - rhs
|
|
elif isinstance(node.op, ast.Mult):
|
|
return lhs * rhs
|
|
elif isinstance(node.op, ast.Div):
|
|
return lhs / rhs
|
|
elif isinstance(node.op, ast.FloorDiv):
|
|
return lhs // rhs
|
|
else:
|
|
note = diagnostic.Diagnostic("note",
|
|
"this operator is not supported {context}",
|
|
{"context": context},
|
|
node.op.loc)
|
|
abort([note])
|
|
else:
|
|
note = diagnostic.Diagnostic("note",
|
|
"this expression is not supported {context}",
|
|
{"context": context},
|
|
node.loc)
|
|
abort([note])
|
|
|
|
def abort(self, message, loc, notes=[]):
|
|
diag = diagnostic.Diagnostic("error", message, {}, loc, notes=notes)
|
|
raise _IndeterminateDelay(diag)
|
|
|
|
def visit_fixpoint(self, node):
|
|
while True:
|
|
self.changed = False
|
|
self.visit(node)
|
|
if not self.changed:
|
|
return
|
|
|
|
def visit_ModuleT(self, node):
|
|
try:
|
|
for stmt in node.body:
|
|
try:
|
|
self.visit(stmt)
|
|
except _UnknownDelay:
|
|
pass # more luck next time?
|
|
except _IndeterminateDelay:
|
|
pass # we don't care; module-level code is never interleaved
|
|
|
|
def visit_function(self, args, body, typ, loc):
|
|
old_args, self.current_args = self.current_args, args
|
|
old_return, self.current_return = self.current_return, None
|
|
old_delay, self.current_delay = self.current_delay, iodelay.Const(0)
|
|
try:
|
|
self.visit(body)
|
|
if not iodelay.is_zero(self.current_delay) and self.current_return is not None:
|
|
self.abort("only return statement at the end of the function "
|
|
"can be interleaved", self.current_return.loc)
|
|
|
|
delay = types.TFixedDelay(self.current_delay.fold())
|
|
except _IndeterminateDelay as error:
|
|
delay = types.TIndeterminateDelay(error.cause)
|
|
self.current_delay = old_delay
|
|
self.current_return = old_return
|
|
self.current_args = old_args
|
|
|
|
if types.is_indeterminate_delay(delay) and types.is_indeterminate_delay(typ.delay):
|
|
# Both delays indeterminate; no point in unifying since that will
|
|
# replace the lazy and more specific error with an eager and more generic
|
|
# error (unification error of delay(?) with delay(?), which is useless).
|
|
return
|
|
|
|
try:
|
|
old_delay = typ.delay.find()
|
|
typ.delay.unify(delay)
|
|
if typ.delay.find() != old_delay:
|
|
self.changed = True
|
|
except types.UnificationError as e:
|
|
printer = types.TypePrinter()
|
|
diag = diagnostic.Diagnostic("fatal",
|
|
"delay {delaya} was inferred for this function, but its delay is already "
|
|
"constrained externally to {delayb}",
|
|
{"delaya": printer.name(delay), "delayb": printer.name(typ.delay)},
|
|
loc)
|
|
self.engine.process(diag)
|
|
|
|
def visit_FunctionDefT(self, node):
|
|
self.visit(node.args.defaults)
|
|
self.visit(node.args.kw_defaults)
|
|
|
|
# We can only handle return in tail position.
|
|
if isinstance(node.body[-1], ast.Return):
|
|
body = node.body[:-1]
|
|
else:
|
|
body = node.body
|
|
self.visit_function(node.args, body, node.signature_type.find(), node.loc)
|
|
|
|
visit_QuotedFunctionDefT = visit_FunctionDefT
|
|
|
|
def visit_LambdaT(self, node):
|
|
self.visit_function(node.args, node.body, node.type.find(), node.loc)
|
|
|
|
def get_iterable_length(self, node, context):
|
|
def abort(notes):
|
|
self.abort("for statement cannot be interleaved because "
|
|
"iteration count is indeterminate",
|
|
node.loc, notes)
|
|
|
|
def evaluate(node):
|
|
return self.evaluate(node, abort, context)
|
|
|
|
if isinstance(node, asttyped.CallT) and types.is_builtin(node.func.type, "range"):
|
|
range_min, range_max, range_step = iodelay.Const(0), None, iodelay.Const(1)
|
|
if len(node.args) == 3:
|
|
range_min, range_max, range_step = map(evaluate, node.args)
|
|
elif len(node.args) == 2:
|
|
range_min, range_max = map(evaluate, node.args)
|
|
elif len(node.args) == 1:
|
|
range_max, = map(evaluate, node.args)
|
|
return (range_max - range_min) // range_step
|
|
else:
|
|
note = diagnostic.Diagnostic("note",
|
|
"this value is not a constant range literal", {},
|
|
node.loc)
|
|
abort([note])
|
|
|
|
def visit_ForT(self, node):
|
|
self.visit(node.iter)
|
|
|
|
old_goto, self.current_goto = self.current_goto, None
|
|
old_delay, self.current_delay = self.current_delay, iodelay.Const(0)
|
|
self.visit(node.body)
|
|
if iodelay.is_zero(self.current_delay):
|
|
self.current_delay = old_delay
|
|
else:
|
|
if self.current_goto is not None:
|
|
self.abort("loop iteration count is indeterminate because of control flow",
|
|
self.current_goto.loc)
|
|
|
|
context = "in an iterable used in a for loop that is being interleaved"
|
|
node.trip_count = self.get_iterable_length(node.iter, context).fold()
|
|
node.trip_interval = self.current_delay.fold()
|
|
self.current_delay = old_delay + node.trip_interval * node.trip_count
|
|
self.current_goto = old_goto
|
|
|
|
self.visit(node.orelse)
|
|
|
|
def visit_goto(self, node):
|
|
self.current_goto = node
|
|
|
|
visit_Break = visit_goto
|
|
visit_Continue = visit_goto
|
|
|
|
def visit_control_flow(self, kind, node):
|
|
old_delay, self.current_delay = self.current_delay, iodelay.Const(0)
|
|
self.generic_visit(node)
|
|
if not iodelay.is_zero(self.current_delay):
|
|
self.abort("{} cannot be interleaved".format(kind), node.loc)
|
|
self.current_delay = old_delay
|
|
|
|
visit_If = lambda self, node: self.visit_control_flow("if statement", node)
|
|
visit_IfExpT = lambda self, node: self.visit_control_flow("if expression", node)
|
|
visit_Try = lambda self, node: self.visit_control_flow("try statement", node)
|
|
|
|
def visit_While(self, node):
|
|
old_goto, self.current_goto = self.current_goto, None
|
|
self.visit_control_flow("while statement", node)
|
|
self.current_goto = old_goto
|
|
|
|
def visit_Return(self, node):
|
|
self.current_return = node
|
|
|
|
def visit_With(self, node):
|
|
self.visit(node.items)
|
|
|
|
context_expr = node.items[0].context_expr
|
|
if len(node.items) == 1 and types.is_builtin(context_expr.type, "interleave"):
|
|
try:
|
|
delays = []
|
|
for stmt in node.body:
|
|
old_delay, self.current_delay = self.current_delay, iodelay.Const(0)
|
|
self.visit(stmt)
|
|
delays.append(self.current_delay)
|
|
self.current_delay = old_delay
|
|
|
|
if any(delays):
|
|
self.current_delay += iodelay.Max(delays)
|
|
except _IndeterminateDelay as error:
|
|
# Interleave failures inside `with` statements are hard failures,
|
|
# since there's no chance that the code will never actually execute
|
|
# inside a `with` statement after all.
|
|
note = diagnostic.Diagnostic("note",
|
|
"while interleaving this 'with interleave:' statement", {},
|
|
node.loc)
|
|
error.cause.notes += [note]
|
|
self.engine.process(error.cause)
|
|
|
|
flow_stmt = None
|
|
if self.current_goto is not None:
|
|
flow_stmt = self.current_goto
|
|
elif self.current_return is not None:
|
|
flow_stmt = self.current_return
|
|
|
|
if flow_stmt is not None:
|
|
note = diagnostic.Diagnostic("note",
|
|
"this '{kind}' statement transfers control out of "
|
|
"the 'with interleave:' statement",
|
|
{"kind": flow_stmt.keyword_loc.source()},
|
|
flow_stmt.loc)
|
|
diag = diagnostic.Diagnostic("error",
|
|
"cannot interleave this 'with interleave:' statement", {},
|
|
node.keyword_loc.join(node.colon_loc), notes=[note])
|
|
self.engine.process(diag)
|
|
|
|
elif len(node.items) == 1 and types.is_builtin(context_expr.type, "sequential"):
|
|
self.visit(node.body)
|
|
else:
|
|
self.abort("with statement cannot be interleaved", node.loc)
|
|
|
|
def visit_CallT(self, node):
|
|
typ = node.func.type.find()
|
|
def abort(notes):
|
|
self.abort("call cannot be interleaved because "
|
|
"an argument cannot be statically evaluated",
|
|
node.loc, notes)
|
|
|
|
if types.is_builtin(typ, "delay"):
|
|
value = self.evaluate(node.args[0], abort=abort,
|
|
context="as an argument for delay()")
|
|
call_delay = iodelay.SToMU(value, ref_period=self.ref_period)
|
|
elif types.is_builtin(typ, "delay_mu"):
|
|
value = self.evaluate(node.args[0], abort=abort,
|
|
context="as an argument for delay_mu()")
|
|
call_delay = value
|
|
elif not types.is_builtin(typ):
|
|
if types.is_function(typ):
|
|
offset = 0
|
|
elif types.is_method(typ):
|
|
offset = 1
|
|
typ = types.get_method_function(typ)
|
|
else:
|
|
assert False
|
|
|
|
delay = typ.find().delay.find()
|
|
if types.is_var(delay):
|
|
raise _UnknownDelay()
|
|
elif delay.is_indeterminate():
|
|
note = diagnostic.Diagnostic("note",
|
|
"function called here", {},
|
|
node.loc)
|
|
cause = delay.cause
|
|
cause = diagnostic.Diagnostic(cause.level, cause.reason, cause.arguments,
|
|
cause.location, cause.highlights,
|
|
cause.notes + [note])
|
|
raise _IndeterminateDelay(cause)
|
|
elif delay.is_fixed():
|
|
args = {}
|
|
for kw_node in node.keywords:
|
|
args[kw_node.arg] = kw_node.value
|
|
for arg_name, arg_node in zip(list(typ.args)[offset:], node.args):
|
|
args[arg_name] = arg_node
|
|
|
|
free_vars = delay.duration.free_vars()
|
|
node.arg_exprs = {
|
|
arg: self.evaluate(args[arg], abort=abort,
|
|
context="in the expression for argument '{}' "
|
|
"that affects I/O delay".format(arg))
|
|
for arg in free_vars
|
|
}
|
|
call_delay = delay.duration.fold(node.arg_exprs)
|
|
else:
|
|
assert False
|
|
else:
|
|
call_delay = iodelay.Const(0)
|
|
|
|
self.current_delay += call_delay
|
|
node.iodelay = call_delay
|