amaranth/amaranth/hdl/_ir.py
2024-04-03 18:47:45 +00:00

1697 lines
78 KiB
Python

from typing import Tuple
from collections import defaultdict, OrderedDict
import enum
import warnings
from .._utils import flatten, to_binary
from .. import tracer, _unused
from . import _ast, _cd, _ir, _nir
__all__ = [
"UnusedElaboratable", "Elaboratable", "DuplicateElaboratable", "DriverConflict", "Fragment",
"Instance", "IOBufferInstance", "PortDirection", "Design", "build_netlist",
]
class UnusedElaboratable(_unused.UnusedMustUse):
# The warning is initially silenced. If everything that has been constructed remains unused,
# it means the application likely crashed (with an exception, or in another way that does not
# call `sys.excepthook`), and it's not necessary to show any warnings.
# Once elaboration starts, the warning is enabled.
_MustUse__silence = True
class Elaboratable(_unused.MustUse):
_MustUse__warning = UnusedElaboratable
class DriverConflict(UserWarning):
pass
class DuplicateElaboratable(Exception):
pass
class Fragment:
@staticmethod
def get(obj, platform):
code = None
origins = []
while True:
if isinstance(obj, Fragment):
if hasattr(obj, "origins"):
obj.origins = tuple(origins)
return obj
elif isinstance(obj, Elaboratable):
code = obj.elaborate.__code__
UnusedElaboratable._MustUse__silence = False
obj._MustUse__used = True
new_obj = obj.elaborate(platform)
else:
raise TypeError(f"Object {obj!r} is not an 'Elaboratable' nor 'Fragment'")
if new_obj is obj:
raise RecursionError(f"Object {obj!r} elaborates to itself")
if new_obj is None and code is not None:
warnings.warn_explicit(
message=".elaborate() returned None; missing return statement?",
category=UserWarning,
filename=code.co_filename,
lineno=code.co_firstlineno)
origins.append(obj)
obj = new_obj
def __init__(self, *, src_loc=None):
self.drivers = OrderedDict()
self.statements = {}
self.domains = OrderedDict()
self.subfragments = []
self.attrs = OrderedDict()
self.generated = OrderedDict()
self.src_loc = src_loc
self.origins = None
self.domains_propagated_up = {}
def add_driver(self, signal, domain="comb"):
assert isinstance(domain, str)
if domain not in self.drivers:
self.drivers[domain] = _ast.SignalSet()
self.drivers[domain].add(signal)
def iter_drivers(self):
for domain, signals in self.drivers.items():
for signal in signals:
yield domain, signal
def iter_comb(self):
if "comb" in self.drivers:
yield from self.drivers["comb"]
def iter_sync(self):
for domain, signals in self.drivers.items():
if domain == "comb":
continue
for signal in signals:
yield domain, signal
def add_domains(self, *domains):
for domain in flatten(domains):
assert isinstance(domain, _cd.ClockDomain)
assert domain.name not in self.domains
self.domains[domain.name] = domain
def iter_domains(self):
yield from self.domains
def add_statements(self, domain, *stmts):
assert isinstance(domain, str)
for stmt in _ast.Statement.cast(stmts):
stmt._MustUse__used = True
self.statements.setdefault(domain, _ast._StatementList()).append(stmt)
def add_subfragment(self, subfragment, name=None, *, src_loc=None):
assert isinstance(subfragment, Fragment)
self.subfragments.append((subfragment, name, src_loc))
def find_subfragment(self, name_or_index):
if isinstance(name_or_index, int):
if name_or_index < len(self.subfragments):
subfragment, name, src_loc = self.subfragments[name_or_index]
return subfragment
raise NameError(f"No subfragment at index #{name_or_index}")
else:
for subfragment, name, src_loc in self.subfragments:
if name == name_or_index:
return subfragment
raise NameError(f"No subfragment with name '{name_or_index}'")
def find_generated(self, *path):
if len(path) > 1:
path_component, *path = path
return self.find_subfragment(path_component).find_generated(*path)
else:
item, = path
return self.generated[item]
def elaborate(self, platform):
return self
def _propagate_domains_up(self, hierarchy=("top",)):
from ._xfrm import DomainRenamer
domain_subfrags = defaultdict(set)
# For each domain defined by a subfragment, determine which subfragments define it.
for i, (subfrag, name, src_loc) in enumerate(self.subfragments):
# First, recurse into subfragments and let them propagate domains up as well.
hier_name = name
if hier_name is None:
hier_name = f"<unnamed #{i}>"
subfrag._propagate_domains_up(hierarchy + (hier_name,))
# Second, classify subfragments by domains they define.
for domain_name, domain in subfrag.domains.items():
if domain.local:
continue
domain_subfrags[domain_name].add((subfrag, name, src_loc, i))
# For each domain defined by more than one subfragment, rename the domain in each
# of the subfragments such that they no longer conflict.
for domain_name, subfrags in domain_subfrags.items():
if len(subfrags) == 1:
continue
names = [n for f, n, s, i in subfrags]
if not all(names):
names = sorted(f"<unnamed #{i}>" if n is None else f"'{n}'"
for f, n, s, i in subfrags)
raise _cd.DomainError(
"Domain '{}' is defined by subfragments {} of fragment '{}'; it is necessary "
"to either rename subfragment domains explicitly, or give names to subfragments"
.format(domain_name, ", ".join(names), ".".join(hierarchy)))
if len(names) != len(set(names)):
names = sorted(f"#{i}" for f, n, s, i in subfrags)
raise _cd.DomainError(
"Domain '{}' is defined by subfragments {} of fragment '{}', some of which "
"have identical names; it is necessary to either rename subfragment domains "
"explicitly, or give distinct names to subfragments"
.format(domain_name, ", ".join(names), ".".join(hierarchy)))
for subfrag, name, src_loc, i in subfrags:
domain_name_map = {domain_name: f"{name}_{domain_name}"}
self.subfragments[i] = (DomainRenamer(domain_name_map)(subfrag), name, src_loc)
# Finally, collect the (now unique) subfragment domains, and merge them into our domains.
for i, (subfrag, name, src_loc) in enumerate(self.subfragments):
hier_name = name
if hier_name is None:
hier_name = f"<unnamed #{i}>"
for domain_name, domain in subfrag.domains.items():
if domain.local:
continue
self.add_domains(domain)
if domain_name in subfrag.domains_propagated_up:
_used_in, defined_in = subfrag.domains_propagated_up[domain_name]
else:
defined_in = (*hierarchy, hier_name)
self.domains_propagated_up[domain_name] = (hierarchy, defined_in)
def _propagate_domains_down(self, hierarchy=("top",)):
# For each domain defined in this fragment, ensure it also exists in all subfragments.
for i, (subfrag, name, src_loc) in enumerate(self.subfragments):
hier_name = name
if hier_name is None:
hier_name = f"<unnamed #{i}>"
for domain in self.iter_domains():
if domain in subfrag.domains:
assert self.domains[domain] is subfrag.domains[domain]
else:
subfrag.add_domains(self.domains[domain])
if domain in self.domains_propagated_up:
_used_in, defined_in = self.domains_propagated_up[domain]
subfrag.domains_propagated_up[domain] = (hierarchy + (hier_name,)), defined_in
subfrag._propagate_domains_down(hierarchy + (hier_name,))
def _create_missing_domains(self, missing_domain, *, platform=None):
from ._xfrm import DomainCollector
collector = DomainCollector()
collector(self)
new_domains = []
for domain_name in collector.used_domains - collector.defined_domains:
if domain_name == "comb":
continue
value = missing_domain(domain_name)
if value is None:
raise _cd.DomainError(f"Domain '{domain_name}' is used but not defined")
if type(value) is _cd.ClockDomain:
self.add_domains(value)
# And expose ports on the newly added clock domain, since it is added directly
# and there was no chance to add any logic driving it.
new_domains.append(value)
else:
new_fragment = Fragment.get(value, platform=platform)
if domain_name not in new_fragment.domains:
defined = new_fragment.domains.keys()
raise _cd.DomainError(
"Fragment returned by missing domain callback does not define "
"requested domain '{}' (defines {})."
.format(domain_name, ", ".join(f"'{n}'" for n in defined)))
self.add_subfragment(new_fragment, f"cd_{domain_name}")
self.add_domains(new_fragment.domains.values())
return new_domains
def _propagate_domains(self, missing_domain, *, platform=None):
self._propagate_domains_up()
self._propagate_domains_down()
new_domains = self._create_missing_domains(missing_domain, platform=platform)
self._propagate_domains_down()
return new_domains
def _prepare_ports(self, ports):
# Normalize ports to a list.
new_ports = []
if isinstance(ports, dict):
for port_name, (signal, dir) in ports.items():
new_ports.append((port_name, signal, dir))
elif isinstance(ports, (list, tuple)):
for port in ports:
if isinstance(port, tuple):
port_name, signal, dir = port
new_ports.append((port_name, signal, dir))
else:
new_ports.append((None, port, None))
else:
msg = f"`ports` must be a dict, a list or a tuple, not {ports!r}"
if isinstance(ports, _ast.Value):
msg += " (did you mean `ports=(<signal>,)`, rather than `ports=<signal>`?)"
raise TypeError(msg)
# Validate ports.
prenamed_ports = set()
for (port_name, signal, dir) in new_ports:
if isinstance(port_name, str):
if port_name in prenamed_ports:
raise TypeError(f"Duplicate port name {port_name!r}")
else:
prenamed_ports.add(port_name)
elif port_name is not None:
raise TypeError(f"Port name must be a string, not {port_name!r}")
if dir is not None and not isinstance(dir, PortDirection):
raise TypeError(
f"Port direction must be a `PortDirection` instance or None, not {dir!r}")
if not isinstance(signal, (_ast.Signal, _ast.ClockSignal, _ast.ResetSignal, _ast.IOPort)):
raise TypeError(f"Only signals and IO ports may be added as ports, not {signal!r}")
return new_ports
def prepare(self, ports=(), *, hierarchy=("top",), missing_domain=lambda name: _cd.ClockDomain(name), propagate_domains=True):
from ._xfrm import DomainLowerer
ports = self._prepare_ports(ports)
if propagate_domains:
new_domains = self._propagate_domains(missing_domain)
for domain in new_domains:
ports.append((None, domain.clk, PortDirection.Input))
if domain.rst is not None:
ports.append((None, domain.rst, PortDirection.Input))
def resolve_signal(signal):
if isinstance(signal, _ast.ClockSignal):
domain = self.domains[signal.domain]
return domain.clk
elif isinstance(signal, _ast.ResetSignal):
domain = self.domains[signal.domain]
if domain.rst is None:
raise ValueError(f"Using ResetSignal for a reset-less domain {signal.domain}")
return domain.rst
else:
return signal
ports = [
(name, resolve_signal(signal), dir)
for name, signal, dir in ports
]
fragment = DomainLowerer()(self)
# Create design and let it do the rest.
return Design(fragment, ports, hierarchy=hierarchy)
class Instance(Fragment):
def __init__(self, type, *args, src_loc=None, src_loc_at=0, **kwargs):
super().__init__(src_loc=src_loc or tracer.get_src_loc(src_loc_at))
self.type = type
self.parameters = OrderedDict()
self.ports = OrderedDict()
for (kind, name, value) in args:
if kind == "a":
self.attrs[name] = value
elif kind == "p":
self.parameters[name] = value
elif kind in ("i", "o", "io"):
if kind == "io":
value = _ast.IOValue.cast(value)
else:
if not isinstance(value, _ast.IOValue):
value = _ast.Value.cast(value)
self.ports[name] = (value, kind)
else:
raise NameError("Instance argument {!r} should be a tuple (kind, name, value) "
"where kind is one of \"a\", \"p\", \"i\", \"o\", or \"io\""
.format((kind, name, value)))
for kw, arg in kwargs.items():
if kw.startswith("a_"):
self.attrs[kw[2:]] = arg
elif kw.startswith("p_"):
self.parameters[kw[2:]] = arg
elif kw.startswith("i_"):
if not isinstance(arg, _ast.IOValue):
arg = _ast.Value.cast(arg)
self.ports[kw[2:]] = (arg, "i")
elif kw.startswith("o_"):
if not isinstance(arg, _ast.IOValue):
arg = _ast.Value.cast(arg)
self.ports[kw[2:]] = (arg, "o")
elif kw.startswith("io_"):
self.ports[kw[3:]] = (_ast.IOValue.cast(arg), "io")
else:
raise NameError("Instance keyword argument {}={!r} does not start with one of "
"\"a_\", \"p_\", \"i_\", \"o_\", or \"io_\""
.format(kw, arg))
class IOBufferInstance(Fragment):
def __init__(self, port, *, i=None, o=None, oe=None, src_loc_at=0, src_loc=None):
super().__init__()
self.port = _ast.IOValue.cast(port)
if i is None:
self.i = None
else:
self.i = _ast.Value.cast(i)
if len(self.port) != len(self.i):
raise ValueError(f"'port' length ({len(self.port)}) doesn't match 'i' length ({len(self.i)})")
if o is None:
if oe is not None:
raise ValueError("'oe' must not be used if 'o' is not used")
self.o = None
self.oe = None
else:
self.o = _ast.Value.cast(o)
if len(self.port) != len(self.o):
raise ValueError(f"'port' length ({len(self.port)}) doesn't match 'o' length ({len(self.o)})")
if oe is None:
self.oe = _ast.Const(1)
else:
self.oe = _ast.Value.cast(oe)
if len(self.oe) != 1:
raise ValueError(f"'oe' length ({len(self.oe)}) must be 1")
self.src_loc = src_loc or tracer.get_src_loc(src_loc_at)
def _add_name(assigned_names, name):
if name in assigned_names:
name = f"{name}${len(assigned_names)}"
assert name not in assigned_names
assigned_names.add(name)
return name
class DesignFragmentInfo:
def __init__(self, parent, depth):
self.parent = parent
self.depth = depth
self.signal_names = _ast.SignalDict()
self.io_port_names = {}
# Fixed up later.
self.name: "tuple[str]" = ()
self.assigned_names = set()
# These two are used as sets, but are stored as dicts to ensure deterministic iteration order.
self.used_signals = _ast.SignalDict()
self.used_io_ports = {}
class Design:
"""Represents a design ready for simulation or netlist building.
Returned by ``Fragment.prepare``."""
def __init__(self, fragment: Fragment, ports, *, hierarchy):
self.fragment = fragment
self.ports = list(ports)
self.hierarchy = hierarchy
self.fragments: dict[Fragment, DesignFragmentInfo] = {}
self.signal_lca = _ast.SignalDict()
self.elaboratables: dict[Elaboratable, Fragment] = {}
self._compute_fragment_depth_parent(fragment, None, 0)
self._collect_used_signals(fragment)
self._add_io_ports()
self._assign_port_names()
for name, conn, dir in self.ports:
if isinstance(conn, _ast.IOPort):
self._use_io_port(fragment, conn)
else:
self._use_signal(fragment, conn)
self._assign_names(fragment, hierarchy)
def _compute_fragment_depth_parent(self, fragment: Fragment, parent: "Fragment | None", depth: int):
"""Recursively computes every fragment's depth and parent."""
self.fragments[fragment] = DesignFragmentInfo(parent, depth)
for subfragment, _name, _src_loc in fragment.subfragments:
self._compute_fragment_depth_parent(subfragment, fragment, depth + 1)
def _use_signal(self, fragment: Fragment, signal: _ast.Signal):
"""Marks a signal as used in a given fragment.
Also marks a signal as used if it has to be routed through a given fragment to get from
one part of hierarchy to another. For this purpose, the ``self.signal_lca`` dictionary
is maintained: for every signal, it stores the topmost fragment in which it has been
marked used so far.
"""
if signal in self.fragments[fragment].used_signals:
return
self.fragments[fragment].used_signals[signal] = None
if signal not in self.signal_lca:
# First time we see a signal.
self.signal_lca[signal] = fragment
return
# Signal already seen — go from current fragment to the LCA, marking everything along
# the way as used.
lca = self.signal_lca[signal]
# First, go up from our fragment until it is no deeper than current LCA.
while self.fragments[lca].depth < self.fragments[fragment].depth:
fragment = self.fragments[fragment].parent
# Early return if we reach a part of tree where the signal is already marked.
if signal in self.fragments[fragment].used_signals:
return
self.fragments[fragment].used_signals[signal] = None
# Second, go up from current LCA until it is no deeper than our fragment.
while self.fragments[lca].depth > self.fragments[fragment].depth:
lca = self.fragments[lca].parent
self.fragments[lca].used_signals[signal] = None
# Now, both fragments are at the same depth. Go up from both until the two paths meet.
while fragment is not lca:
lca = self.fragments[lca].parent
self.fragments[lca].used_signals[signal] = None
fragment = self.fragments[fragment].parent
self.fragments[fragment].used_signals[signal] = None
self.signal_lca[signal] = lca
def _use_io_port(self, fragment: Fragment, port: _ast.IOPort):
"""Marks an IO port as used in a given fragment and all its ancestors."""
frag_info = self.fragments[fragment]
if port in frag_info.used_io_ports:
return
frag_info.used_io_ports[port] = None
if frag_info.parent is not None:
self._use_io_port(frag_info.parent, port)
def _collect_used_signals(self, fragment: Fragment):
"""Collects used signals and IO ports for a fragment and all its subfragments."""
from . import _mem
if isinstance(fragment, _ir.Instance):
for conn, kind in fragment.ports.values():
if isinstance(conn, _ast.IOValue):
for port in conn._ioports():
self._use_io_port(fragment, port)
elif isinstance(conn, _ast.Value):
for signal in conn._rhs_signals():
self._use_signal(fragment, signal)
else:
assert False # :nocov:
elif isinstance(fragment, _ir.IOBufferInstance):
for port in fragment.port._ioports():
self._use_io_port(fragment, port)
if fragment.i is not None:
for signal in fragment.i._rhs_signals():
self._use_signal(fragment, signal)
if fragment.o is not None:
for signal in fragment.o._rhs_signals():
self._use_signal(fragment, signal)
for signal in fragment.oe._rhs_signals():
self._use_signal(fragment, signal)
elif isinstance(fragment, _mem.MemoryInstance):
for port in fragment._read_ports:
for signal in port._addr._rhs_signals():
self._use_signal(fragment, signal)
for signal in port._data._rhs_signals():
self._use_signal(fragment, signal)
for signal in port._en._rhs_signals():
self._use_signal(fragment, signal)
if port._domain != "comb":
domain = fragment.domains[port._domain]
self._use_signal(fragment, domain.clk)
if domain.rst is not None:
self._use_signal(fragment, domain.rst)
for port in fragment._write_ports:
for signal in port._addr._rhs_signals():
self._use_signal(fragment, signal)
for signal in port._data._rhs_signals():
self._use_signal(fragment, signal)
for signal in port._en._rhs_signals():
self._use_signal(fragment, signal)
domain = fragment.domains[port._domain]
self._use_signal(fragment, domain.clk)
if domain.rst is not None:
self._use_signal(fragment, domain.rst)
else:
for domain_name, statements in fragment.statements.items():
if domain_name != "comb":
domain = fragment.domains[domain_name]
self._use_signal(fragment, domain.clk)
if domain.rst is not None:
self._use_signal(fragment, domain.rst)
for statement in statements:
for signal in statement._lhs_signals() | statement._rhs_signals():
if not isinstance(signal, (_ast.ClockSignal, _ast.ResetSignal)):
self._use_signal(fragment, signal)
for subfragment, _name, _src_loc in fragment.subfragments:
self._collect_used_signals(subfragment)
def _add_io_ports(self):
"""Adds all used IO ports to our list of top-level ports, if they aren't there already."""
io_ports = {conn for name, conn, dir in self.ports if isinstance(conn, _ast.IOPort)}
for port in self.fragments[self.fragment].used_io_ports:
if port not in io_ports:
self.ports.append((None, port, None))
def _assign_port_names(self):
"""Assigns names to all ports that haven't been explicitly named."""
new_ports = []
assigned_names = {name for name, conn, dir in self.ports if name is not None}
for name, conn, dir in self.ports:
if name is None:
if conn.name == "": # Nothing to name this port!
raise TypeError("Signals with private names cannot be used in unnamed top-level ports")
name = _add_name(assigned_names, conn.name)
assigned_names.add(name)
new_ports.append((name, conn, dir))
self.ports = new_ports
def _assign_names(self, fragment: Fragment, hierarchy: "tuple[str]"):
"""Assign names to signals and IO ports used in a given fragment, as well as its
subfragments.
The signal mapping is set in ``self.signal_names``, and the IO port mapping is set in
``self.io_port_names``. Because names are deduplicated using local information only,
the same signal used in a different fragment may get a different name.
Subfragments may not necessarily have a name. This method assigns every such subfragment
a name, ``U$<number>``, where ``<number>`` is based on its location in the hierarchy.
Subfragment names may collide with signal names safely in Amaranth, but this may confuse
backends. This method assigns every such subfragment a new name.
Arguments
---------
hierarchy : tuple of str
Name of this fragment.
"""
frag_info = self.fragments[fragment]
frag_info.name = hierarchy
if fragment.origins is not None:
for origin in fragment.origins:
if origin in self.elaboratables:
other_hierarchy = self.fragments[self.elaboratables[origin]].name
raise DuplicateElaboratable(f"Elaboratable {origin!r} is included twice "
f"in the hierarchy, as {'.'.join(other_hierarchy)} "
f"and {'.'.join(hierarchy)}")
self.elaboratables[origin] = fragment
if fragment is self.fragment:
# Reserve names for top-level ports. If equal to the signal name, let the signal share it.
for name, conn, _dir in self.ports:
frag_info.assigned_names.add(name)
if isinstance(conn, _ast.Signal) and conn.name == name:
frag_info.signal_names[conn] = name
elif isinstance(conn, _ast.IOPort) and conn.name == name:
frag_info.io_port_names[conn] = name
for signal in frag_info.used_signals:
if signal not in frag_info.signal_names and signal.name != "": # Private name shouldn't be added.
frag_info.signal_names[signal] = _add_name(frag_info.assigned_names, signal.name)
for port in frag_info.used_io_ports:
if port not in frag_info.io_port_names:
frag_info.io_port_names[port] = _add_name(frag_info.assigned_names, port.name)
for subfragment_index, (subfragment, subfragment_name, subfragment_src_loc) in enumerate(fragment.subfragments):
if subfragment_name is None:
subfragment_name = f"U${subfragment_index}"
subfragment_name = _add_name(frag_info.assigned_names, subfragment_name)
self._assign_names(subfragment, hierarchy=(*hierarchy, subfragment_name))
############################################################################################### >:3
class PortDirection(enum.Enum):
Input = "input"
Output = "output"
Inout = "inout"
class NetlistDriver:
def __init__(self, module_idx: int, signal: _ast.Signal,
domain: '_cd.ClockDomain | None', *, src_loc):
self.module_idx = module_idx
self.signal = signal
self.domain = domain
self.src_loc = src_loc
self.assignments = []
def emit_value(self, builder):
if self.domain is None:
init = _ast.Const(self.signal.init, len(self.signal))
default, _signed = builder.emit_rhs(self.module_idx, init)
else:
default = builder.emit_signal(self.signal)
if len(self.assignments) == 1:
assign, = self.assignments
if assign.cond == 1 and assign.start == 0 and len(assign.value) == len(default):
return assign.value
cell = _nir.AssignmentList(self.module_idx, default=default, assignments=self.assignments,
src_loc=self.signal.src_loc)
return builder.netlist.add_value_cell(len(default), cell)
class NetlistEmitter:
def __init__(self, netlist: _nir.Netlist, design, *, all_undef_to_ff=False):
self.netlist = netlist
self.design = design
self.all_undef_to_ff = all_undef_to_ff
self.drivers = _ast.SignalDict()
self.io_ports: dict[_ast.IOPort, int] = {}
self.rhs_cache: dict[int, Tuple[_nir.Value, bool, _ast.Value]] = {}
self.fragment_module_idx: dict[Fragment, int] = {}
# Collected for driver conflict diagnostics only.
self.late_net_to_signal = {}
self.connect_src_loc = {}
self.ionet_src_loc = {}
def emit_signal(self, signal) -> _nir.Value:
if signal in self.netlist.signals:
return self.netlist.signals[signal]
value = self.netlist.alloc_late_value(len(signal))
self.netlist.signals[signal] = value
for bit, net in enumerate(value):
self.late_net_to_signal[net] = (signal, bit)
return value
def emit_io(self, value: _ast.IOValue) -> _nir.IOValue:
if isinstance(value, _ast.IOPort):
if value not in self.io_ports:
port = len(self.netlist.io_ports)
self.netlist.io_ports.append(value)
self.io_ports[value] = _nir.IOValue(
_nir.IONet.from_port(port, bit)
for bit in range(0, len(value))
)
return self.io_ports[value]
elif isinstance(value, _ast.IOConcat):
result = []
for part in value.parts:
result += self.emit_io(part)
return _nir.IOValue(result)
elif isinstance(value, _ast.IOSlice):
return self.emit_io(value.value)[value.start:value.stop]
else:
raise TypeError # :nocov:
def emit_io_use(self, value: _ast.IOValue, *, src_loc) -> _nir.IOValue:
res = self.emit_io(value)
for net in res:
if net not in self.ionet_src_loc:
self.ionet_src_loc[net] = src_loc
else:
prev_src_loc = self.ionet_src_loc[net]
port = self.netlist.io_ports[net.port]
raise DriverConflict(f"Bit {net.bit} of I/O port {port!r} used twice, at "
f"{prev_src_loc[0]}:{prev_src_loc[1]} and {src_loc[0]}:{src_loc[1]}")
return res
# Used for instance outputs and read port data, not used for actual assignments.
def emit_lhs(self, value: _ast.Value):
if isinstance(value, _ast.Signal):
return self.emit_signal(value)
elif isinstance(value, _ast.Concat):
result = []
for part in value.parts:
result += self.emit_lhs(part)
return _nir.Value(result)
elif isinstance(value, _ast.Slice):
return self.emit_lhs(value.value)[value.start:value.stop]
elif isinstance(value, _ast.Operator):
assert value.operator in ('u', 's')
return self.emit_lhs(value.operands[0])
else:
raise TypeError # :nocov:
def extend(self, value: _nir.Value, signed: bool, width: int):
nets = list(value)
while len(nets) < width:
if signed:
nets.append(nets[-1])
else:
nets.append(_nir.Net.from_const(0))
return _nir.Value(nets)
def emit_operator(self, module_idx: int, operator: str, *inputs: _nir.Value, src_loc):
op = _nir.Operator(module_idx, operator=operator, inputs=inputs, src_loc=src_loc)
return self.netlist.add_value_cell(op.width, op)
def unify_shapes_bitwise(self,
operand_a: _nir.Value, signed_a: bool, operand_b: _nir.Value, signed_b: bool):
shape = _ast.Shape._unify((
_ast.Shape(len(operand_a), signed_a),
_ast.Shape(len(operand_b), signed_b),
))
operand_a = self.extend(operand_a, signed_a, shape.width)
operand_b = self.extend(operand_b, signed_b, shape.width)
return (operand_a, operand_b, shape.signed)
def emit_rhs(self, module_idx: int, value: _ast.Value) -> Tuple[_nir.Value, bool]:
"""Emits a RHS value, returns a tuple of (value, is_signed)"""
try:
result, signed, value = self.rhs_cache[id(value)]
return result, signed
except KeyError:
pass
if isinstance(value, _ast.Const):
shape = value.shape()
result = _nir.Value.from_const(value.value, shape.width)
signed = shape.signed
elif isinstance(value, _ast.Signal):
shape = value.shape()
result = self.emit_signal(value)
signed = shape.signed
elif isinstance(value, _ast.Operator):
if len(value.operands) == 1:
operand_a, signed_a = self.emit_rhs(module_idx, value.operands[0])
if value.operator == 's':
result = operand_a
signed = True
elif value.operator == 'u':
result = operand_a
signed = False
elif value.operator == '-':
operand_a = self.extend(operand_a, signed_a, len(operand_a) + 1)
result = self.emit_operator(module_idx, '-', operand_a,
src_loc=value.src_loc)
signed = True
elif value.operator == '~':
result = self.emit_operator(module_idx, '~', operand_a,
src_loc=value.src_loc)
signed = signed_a
elif value.operator in ('b', 'r|', 'r&', 'r^'):
result = self.emit_operator(module_idx, value.operator, operand_a,
src_loc=value.src_loc)
signed = False
else:
assert False # :nocov:
elif len(value.operands) == 2:
operand_a, signed_a = self.emit_rhs(module_idx, value.operands[0])
operand_b, signed_b = self.emit_rhs(module_idx, value.operands[1])
if value.operator in ('|', '&', '^'):
operand_a, operand_b, signed = \
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
result = self.emit_operator(module_idx, value.operator, operand_a, operand_b,
src_loc=value.src_loc)
elif value.operator in ('+', '-'):
operand_a, operand_b, signed = \
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
width = len(operand_a) + 1
operand_a = self.extend(operand_a, signed, width)
operand_b = self.extend(operand_b, signed, width)
result = self.emit_operator(module_idx, value.operator, operand_a, operand_b,
src_loc=value.src_loc)
if value.operator == '-':
signed = True
elif value.operator == '*':
width = len(operand_a) + len(operand_b)
operand_a = self.extend(operand_a, signed_a, width)
operand_b = self.extend(operand_b, signed_b, width)
result = self.emit_operator(module_idx, '*', operand_a, operand_b,
src_loc=value.src_loc)
signed = signed_a or signed_b
elif value.operator == '//':
width = len(operand_a) + signed_b
operand_a, operand_b, signed = \
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
if len(operand_a) < width:
operand_a = self.extend(operand_a, signed, width)
operand_b = self.extend(operand_b, signed, width)
operator = 's//' if signed else 'u//'
result = _nir.Value(
self.emit_operator(module_idx, operator, operand_a, operand_b,
src_loc=value.src_loc)[:width]
)
elif value.operator == '%':
width = len(operand_b)
operand_a, operand_b, signed = \
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
operator = 's%' if signed else 'u%'
result = _nir.Value(
self.emit_operator(module_idx, operator, operand_a, operand_b,
src_loc=value.src_loc)[:width]
)
signed = signed_b
elif value.operator == '<<':
operand_a = self.extend(operand_a, signed_a,
len(operand_a) + 2 ** len(operand_b) - 1)
result = self.emit_operator(module_idx, '<<', operand_a, operand_b,
src_loc=value.src_loc)
signed = signed_a
elif value.operator == '>>':
operator = 's>>' if signed_a else 'u>>'
result = self.emit_operator(module_idx, operator, operand_a, operand_b,
src_loc=value.src_loc)
signed = signed_a
elif value.operator in ('==', '!='):
operand_a, operand_b, signed = \
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
result = self.emit_operator(module_idx, value.operator, operand_a, operand_b,
src_loc=value.src_loc)
signed = False
elif value.operator in ('<', '>', '<=', '>='):
operand_a, operand_b, signed = \
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
operator = ('s' if signed else 'u') + value.operator
result = self.emit_operator(module_idx, operator, operand_a, operand_b,
src_loc=value.src_loc)
signed = False
else:
assert False # :nocov:
else:
assert False # :nocov:
elif isinstance(value, _ast.Slice):
inner, _signed = self.emit_rhs(module_idx, value.value)
result = _nir.Value(inner[value.start:value.stop])
signed = False
elif isinstance(value, _ast.Part):
inner, signed = self.emit_rhs(module_idx, value.value)
offset, _signed = self.emit_rhs(module_idx, value.offset)
cell = _nir.Part(module_idx, value=inner, value_signed=signed, width=value.width,
stride=value.stride, offset=offset, src_loc=value.src_loc)
result = self.netlist.add_value_cell(value.width, cell)
signed = False
elif isinstance(value, _ast.SwitchValue):
test, _signed = self.emit_rhs(module_idx, value.test)
if (len(value.cases) == 2 and
value.cases[0][0] == ("0" * len(test),) and
value.cases[1][0] is None):
operand_a, signed_a = self.emit_rhs(module_idx, value.cases[1][1])
operand_b, signed_b = self.emit_rhs(module_idx, value.cases[0][1])
if len(test) != 1:
test = self.emit_operator(module_idx, 'b', test, src_loc=value.src_loc)
operand_a, operand_b, signed = \
self.unify_shapes_bitwise(operand_a, signed_a, operand_b, signed_b)
result = self.emit_operator(module_idx, 'm', test, operand_a, operand_b,
src_loc=value.src_loc)
else:
conds = []
elems = []
for patterns, elem, in value.cases:
if patterns is not None:
if not patterns:
# Hack: empty pattern set cannot be supported by RTLIL.
continue
for pattern in patterns:
assert len(pattern) == len(test)
cell = _nir.Matches(module_idx, value=test, patterns=patterns,
src_loc=value.src_loc)
net, = self.netlist.add_value_cell(1, cell)
conds.append(net)
else:
conds.append(_nir.Net.from_const(1))
elems.append(self.emit_rhs(module_idx, elem))
cell = _nir.PriorityMatch(module_idx, en=_nir.Net.from_const(1),
inputs=_nir.Value(conds),
src_loc=value.src_loc)
conds = self.netlist.add_value_cell(len(conds), cell)
shape = _ast.Shape._unify(
_ast.Shape(len(value), signed)
for value, signed in elems
)
elems = tuple(self.extend(elem, elem_signed, shape.width) for elem, elem_signed in elems)
assignments = [
_nir.Assignment(cond=subcond, start=0, value=elem, src_loc=value.src_loc)
for subcond, elem in zip(conds, elems)
]
cell = _nir.AssignmentList(module_idx, default=_nir.Value.from_const(0, shape.width),
assignments=assignments, src_loc=value.src_loc)
result = self.netlist.add_value_cell(shape.width, cell)
signed = shape.signed
elif isinstance(value, _ast.Concat):
nets = []
for val in value.parts:
inner, _signed = self.emit_rhs(module_idx, val)
for net in inner:
nets.append(net)
result = _nir.Value(nets)
signed = False
elif isinstance(value, _ast.AnyValue):
result = self.netlist.add_value_cell(value.width,
_nir.AnyValue(module_idx, kind=value.kind.value, width=value.width,
src_loc=value.src_loc))
signed = value.signed
elif isinstance(value, _ast.Initial):
result = self.netlist.add_value_cell(1, _nir.Initial(module_idx, src_loc=value.src_loc))
signed = False
else:
assert False # :nocov:
assert value.shape().width == len(result), \
f"Value {value!r} with shape {value.shape()!r} does not match " \
f"result with width {len(result)}"
# Add the value itself to the cache to make sure `id(value)` remains allocated and pointing
# at `value`. This would be a weakref.WeakKeyDictionary if `value` was hashable.
self.rhs_cache[id(value)] = result, signed, value
return (result, signed)
def connect(self, lhs: _nir.Value, rhs: _nir.Value, *, src_loc):
assert len(lhs) == len(rhs)
for left, right in zip(lhs, rhs):
if left in self.netlist.connections:
signal, bit = self.late_net_to_signal[left]
other_src_loc = self.connect_src_loc[left]
raise _ir.DriverConflict(f"Bit {bit} of signal {signal!r} has multiple drivers: "
f"{other_src_loc[0]}:{other_src_loc[1]} and {src_loc[0]}:{src_loc[1]}")
self.netlist.connections[left] = right
self.connect_src_loc[left] = src_loc
def emit_assign(self, module_idx: int, cd: "_cd.ClockDomain | None", lhs: _ast.Value, lhs_start: int, rhs: _nir.Value, cond: _nir.Net, *, src_loc):
# Assign rhs to lhs[lhs_start:lhs_start+len(rhs)]
if isinstance(lhs, _ast.Signal):
if lhs in self.drivers:
driver = self.drivers[lhs]
if driver.domain is not cd:
domain_name = cd.name if cd is not None else "comb"
other_domain_name = driver.domain.name if driver.domain is not None else "comb"
raise _ir.DriverConflict(
f"Signal {lhs!r} driven from domain {domain_name} at {src_loc[0]}:{src_loc[1]} and domain "
f"{other_domain_name} at {driver.src_loc[0]}:{driver.src_loc[1]}")
if driver.module_idx != module_idx:
mod_name = ".".join(self.netlist.modules[module_idx].name or ("<toplevel>",))
other_mod_name = \
".".join(self.netlist.modules[driver.module_idx].name or ("<toplevel>",))
raise _ir.DriverConflict(
f"Signal {lhs!r} driven from module {mod_name} at {src_loc[0]}:{src_loc[1]} and "
f"module {other_mod_name} at {driver.src_loc[0]}:{driver.src_loc[1]}")
else:
driver = NetlistDriver(module_idx, lhs, domain=cd, src_loc=src_loc)
self.drivers[lhs] = driver
driver.assignments.append(_nir.Assignment(cond=cond, start=lhs_start, value=rhs,
src_loc=src_loc))
elif isinstance(lhs, _ast.Slice):
self.emit_assign(module_idx, cd, lhs.value, lhs_start + lhs.start, rhs, cond, src_loc=src_loc)
elif isinstance(lhs, _ast.Concat):
part_stop = 0
for part in lhs.parts:
part_start = part_stop
part_len = len(part)
part_stop = part_start + part_len
if lhs_start >= part_stop:
continue
if lhs_start + len(rhs) <= part_start:
continue
if lhs_start < part_start:
part_lhs_start = 0
part_rhs_start = part_start - lhs_start
else:
part_lhs_start = lhs_start - part_start
part_rhs_start = 0
if lhs_start + len(rhs) >= part_stop:
part_rhs_stop = part_stop - lhs_start
else:
part_rhs_stop = len(rhs)
self.emit_assign(module_idx, cd, part, part_lhs_start, rhs[part_rhs_start:part_rhs_stop], cond, src_loc=src_loc)
elif isinstance(lhs, _ast.Part):
offset, _signed = self.emit_rhs(module_idx, lhs.offset)
width = len(lhs.value)
num_cases = min((width + lhs.stride - 1) // lhs.stride, 1 << len(offset))
conds = []
for case_index in range(num_cases):
cell = _nir.Matches(module_idx, value=offset,
patterns=(to_binary(case_index, len(offset)),),
src_loc=lhs.src_loc)
subcond, = self.netlist.add_value_cell(1, cell)
conds.append(subcond)
conds = _nir.Value(conds)
cell = _nir.PriorityMatch(module_idx, en=cond, inputs=conds, src_loc=lhs.src_loc)
conds = self.netlist.add_value_cell(len(conds), cell)
for idx, subcond in enumerate(conds):
start = lhs_start + idx * lhs.stride
if start >= width:
continue
if start + len(rhs) >= width:
subrhs = rhs[:width - start]
else:
subrhs = rhs
self.emit_assign(module_idx, cd, lhs.value, start, subrhs, subcond, src_loc=src_loc)
elif isinstance(lhs, _ast.SwitchValue):
test, _signed = self.emit_rhs(module_idx, lhs.test)
conds = []
elems = []
for patterns, elem in lhs.cases:
if patterns is not None:
if not patterns:
# Hack: empty pattern set cannot be supported by RTLIL.
continue
for pattern in patterns:
assert len(pattern) == len(test)
cell = _nir.Matches(module_idx, value=test, patterns=patterns,
src_loc=lhs.src_loc)
net, = self.netlist.add_value_cell(1, cell)
conds.append(net)
else:
conds.append(_nir.Net.from_const(1))
elems.append(elem)
conds = _nir.Value(conds)
cell = _nir.PriorityMatch(module_idx, en=_nir.Net.from_const(1),
inputs=conds, src_loc=lhs.src_loc)
conds = self.netlist.add_value_cell(len(conds), cell)
for subcond, val in zip(conds, elems):
self.emit_assign(module_idx, cd, val, lhs_start, rhs[:len(val)], subcond, src_loc=src_loc)
elif isinstance(lhs, _ast.Operator):
assert lhs.operator in ('u', 's')
self.emit_assign(module_idx, cd, lhs.operands[0], lhs_start, rhs, cond, src_loc=src_loc)
else:
assert False # :nocov:
def emit_format(self, module_idx, format):
chunks = []
for chunk in format._chunks:
if isinstance(chunk, str):
chunks.append(chunk)
else:
value, format_desc = chunk
value, signed = self.emit_rhs(module_idx, value)
chunks.append(_nir.FormatValue(value, format_desc, signed=signed))
return _nir.Format(chunks)
def emit_stmt(self, module_idx: int, fragment: _ir.Fragment, domain: str,
stmt: _ast.Statement, cond: _nir.Net):
if domain == "comb":
cd: _cd.ClockDomain | None = None
else:
cd = fragment.domains[domain]
if isinstance(stmt, _ast.Assign):
rhs, signed = self.emit_rhs(module_idx, stmt.rhs)
width = len(stmt.lhs)
if len(rhs) > width:
rhs = _nir.Value(rhs[:width])
if len(rhs) < width:
rhs = self.extend(rhs, signed, width)
self.emit_assign(module_idx, cd, stmt.lhs, 0, rhs, cond, src_loc=stmt.src_loc)
elif isinstance(stmt, _ast.Print):
en_cell = _nir.AssignmentList(module_idx,
default=_nir.Value.zeros(),
assignments=[
_nir.Assignment(cond=cond, start=0, value=_nir.Value.ones(),
src_loc=stmt.src_loc)
],
src_loc=stmt.src_loc)
cond, = self.netlist.add_value_cell(1, en_cell)
format = self.emit_format(module_idx, stmt.message)
if cd is None:
cell = _nir.AsyncPrint(module_idx, en=cond,
format=format, src_loc=stmt.src_loc)
else:
clk, = self.emit_signal(cd.clk)
cell = _nir.SyncPrint(module_idx, en=cond,
clk=clk, clk_edge=cd.clk_edge,
format=format, src_loc=stmt.src_loc)
self.netlist.add_cell(cell)
elif isinstance(stmt, _ast.Property):
test, _signed = self.emit_rhs(module_idx, stmt.test)
if len(test) != 1:
test = self.emit_operator(module_idx, 'b', test, src_loc=stmt.src_loc)
test, = test
en_cell = _nir.AssignmentList(module_idx,
default=_nir.Value.zeros(),
assignments=[
_nir.Assignment(cond=cond, start=0, value=_nir.Value.ones(),
src_loc=stmt.src_loc)
],
src_loc=stmt.src_loc)
cond, = self.netlist.add_value_cell(1, en_cell)
if stmt.message is None:
format = None
else:
format = self.emit_format(module_idx, stmt.message)
if cd is None:
cell = _nir.AsyncProperty(module_idx, kind=stmt.kind.value, test=test, en=cond,
format=format, src_loc=stmt.src_loc)
else:
clk, = self.emit_signal(cd.clk)
cell = _nir.SyncProperty(module_idx, kind=stmt.kind.value, test=test, en=cond,
clk=clk, clk_edge=cd.clk_edge,
format=format, src_loc=stmt.src_loc)
self.netlist.add_cell(cell)
elif isinstance(stmt, _ast.Switch):
test, _signed = self.emit_rhs(module_idx, stmt.test)
conds = []
case_stmts = []
for patterns, stmts, case_src_loc in stmt.cases:
if patterns is not None:
if not patterns:
# Hack: empty pattern set cannot be supported by RTLIL.
continue
for pattern in patterns:
assert len(pattern) == len(test)
cell = _nir.Matches(module_idx, value=test, patterns=patterns,
src_loc=case_src_loc)
net, = self.netlist.add_value_cell(1, cell)
conds.append(net)
else:
conds.append(_nir.Net.from_const(1))
case_stmts.append(stmts)
cell = _nir.PriorityMatch(module_idx, en=cond, inputs=_nir.Value(conds),
src_loc=stmt.src_loc)
conds = self.netlist.add_value_cell(len(conds), cell)
for subcond, substmts in zip(conds, case_stmts):
for substmt in substmts:
self.emit_stmt(module_idx, fragment, domain, substmt, subcond)
else:
assert False # :nocov:
def emit_iobuffer(self, module_idx: int, instance: _ir.IOBufferInstance):
port = self.emit_io_use(instance.port, src_loc=instance.src_loc)
if instance.o is None:
o = None
oe = None
dir = _nir.IODirection.Input
else:
o, _signed = self.emit_rhs(module_idx, instance.o)
(oe,), _signed = self.emit_rhs(module_idx, instance.oe)
assert len(port) == len(o)
if instance.i is None:
dir = _nir.IODirection.Output
else:
dir = _nir.IODirection.Bidir
cell = _nir.IOBuffer(module_idx, port=port, dir=dir, o=o, oe=oe, src_loc=instance.src_loc)
value = self.netlist.add_value_cell(len(port), cell)
if instance.i is not None:
self.connect(self.emit_lhs(instance.i), value, src_loc=instance.src_loc)
def emit_memory(self, module_idx: int, fragment: '_mem.MemoryInstance', name: str):
cell = _nir.Memory(module_idx,
width=_ast.Shape.cast(fragment._data._shape).width,
depth=fragment._data._depth,
init=fragment._data._init._raw,
name=name,
attributes=fragment._attrs,
src_loc=fragment.src_loc,
)
return self.netlist.add_cell(cell)
def emit_write_port(self, module_idx: int, fragment: '_mem.MemoryInstance',
port: '_mem.MemoryInstance._WritePort', memory: int):
data, _signed = self.emit_rhs(module_idx, port._data)
addr, _signed = self.emit_rhs(module_idx, port._addr)
en, _signed = self.emit_rhs(module_idx, port._en)
en = _nir.Value([en[bit // port._granularity] for bit in range(len(port._data))])
cd = fragment.domains[port._domain]
clk, = self.emit_signal(cd.clk)
cell = _nir.SyncWritePort(module_idx,
memory=memory,
data=data,
addr=addr,
en=en,
clk=clk,
clk_edge=cd.clk_edge,
src_loc=port._data.src_loc,
)
return self.netlist.add_cell(cell)
def emit_read_port(self, module_idx: int, fragment: '_mem.MemoryInstance',
port: '_mem.MemoryInstance._ReadPort', memory: int,
write_ports: 'list[int]'):
addr, _signed = self.emit_rhs(module_idx, port._addr)
if port._domain == "comb":
cell = _nir.AsyncReadPort(module_idx,
memory=memory,
width=len(port._data),
addr=addr,
src_loc=port._data.src_loc,
)
else:
(en,), _signed = self.emit_rhs(module_idx, port._en)
cd = fragment.domains[port._domain]
clk, = self.emit_signal(cd.clk)
cell = _nir.SyncReadPort(module_idx,
memory=memory,
width=len(port._data),
addr=addr,
en=en,
clk=clk,
clk_edge=cd.clk_edge,
transparent_for=tuple(write_ports[idx] for idx in port._transparent_for),
src_loc=port._data.src_loc,
)
data = self.netlist.add_value_cell(len(port._data), cell)
self.connect(self.emit_lhs(port._data), data, src_loc=port._data.src_loc)
def emit_instance(self, module_idx: int, instance: _ir.Instance, name: str):
ports_i = {}
ports_o = {}
ports_io = {}
outputs = []
next_output_bit = 0
for port_name, (port_conn, dir) in instance.ports.items():
if isinstance(port_conn, _ast.IOValue):
if dir == 'i':
xlat_dir = _nir.IODirection.Input
elif dir == 'o':
xlat_dir = _nir.IODirection.Output
elif dir == 'io':
xlat_dir = _nir.IODirection.Bidir
else:
assert False # :nocov:
ports_io[port_name] = (self.emit_io_use(port_conn, src_loc=instance.src_loc), xlat_dir)
elif dir == 'i':
ports_i[port_name], _signed = self.emit_rhs(module_idx, port_conn)
elif dir == 'o':
port_conn = self.emit_lhs(port_conn)
ports_o[port_name] = (next_output_bit, len(port_conn))
outputs.append((next_output_bit, port_conn))
next_output_bit += len(port_conn)
else:
assert False # :nocov:
cell = _nir.Instance(module_idx,
type=instance.type,
name=name,
parameters=instance.parameters,
attributes=instance.attrs,
ports_i=ports_i,
ports_o=ports_o,
ports_io=ports_io,
src_loc=instance.src_loc,
)
output_nets = self.netlist.add_value_cell(width=next_output_bit, cell=cell)
for start_bit, port_conn in outputs:
self.connect(port_conn, _nir.Value(output_nets[start_bit:start_bit + len(port_conn)]),
src_loc=instance.src_loc)
def emit_top_ports(self, fragment: _ir.Fragment):
next_input_bit = 2 # 0 and 1 are reserved for constants
top = self.netlist.top
for name, signal, dir in self.design.ports:
if isinstance(signal, _ast.IOPort):
continue
signal_value = self.emit_signal(signal)
if dir is None:
is_driven = False
for net in signal_value:
if net in self.netlist.connections:
is_driven = True
if is_driven:
dir = PortDirection.Output
else:
dir = PortDirection.Input
if dir == PortDirection.Input:
top.ports_i[name] = (next_input_bit, len(signal))
value = _nir.Value(
_nir.Net.from_cell(0, bit)
for bit in range(next_input_bit, next_input_bit + len(signal))
)
next_input_bit += len(signal)
self.connect(signal_value, value, src_loc=signal.src_loc)
elif dir == PortDirection.Output:
top.ports_o[name] = signal_value
elif dir == PortDirection.Inout:
raise ValueError(f"Port direction 'Inout' can only be used for 'IOPort', not 'Signal'")
else:
raise ValueError(f"Invalid port direction {dir!r}")
def emit_drivers(self):
for driver in self.drivers.values():
if (driver.domain is not None and
driver.domain.rst is not None and
not driver.domain.async_reset and
not driver.signal.reset_less):
cell = _nir.Matches(driver.module_idx,
value=self.emit_signal(driver.domain.rst),
patterns=("1",),
src_loc=driver.domain.rst.src_loc)
cond, = self.netlist.add_value_cell(1, cell)
cell = _nir.PriorityMatch(driver.module_idx, en=_nir.Net.from_const(1),
inputs=_nir.Value(cond),
src_loc=driver.domain.rst.src_loc)
cond, = self.netlist.add_value_cell(1, cell)
init = _nir.Value.from_const(driver.signal.init, len(driver.signal))
driver.assignments.append(_nir.Assignment(cond=cond, start=0,
value=init, src_loc=driver.signal.src_loc))
value = driver.emit_value(self)
if driver.domain is not None:
clk, = self.emit_signal(driver.domain.clk)
if driver.domain.rst is not None and driver.domain.async_reset and not driver.signal.reset_less:
arst, = self.emit_signal(driver.domain.rst)
else:
arst = _nir.Net.from_const(0)
cell = _nir.FlipFlop(driver.module_idx,
data=value,
init=driver.signal.init,
clk=clk,
clk_edge=driver.domain.clk_edge,
arst=arst,
attributes=driver.signal.attrs,
src_loc=driver.signal.src_loc,
)
value = self.netlist.add_value_cell(len(value), cell)
if driver.assignments:
src_loc = driver.assignments[0].src_loc
else:
src_loc = driver.signal.src_loc
self.connect(self.emit_signal(driver.signal), value, src_loc=src_loc)
def emit_undef_ff(self):
# Connect all completely undriven signals to flip-flops with const-0 clock. This is used
# for simulation targets, so that undriven signals have allocated storage that can be
# used by the testbench to drive them, instead of being hardwired to the init value
# constant.
for signal, value in self.netlist.signals.items():
fragment = self.design.signal_lca[signal]
module_idx = self.fragment_module_idx[fragment]
pos = 0
while pos < len(signal):
net = value[pos]
if not net.is_late or net in self.netlist.connections:
pos += 1
else:
end_pos = pos
while (end_pos < len(signal) and
value[end_pos].is_late and
value[end_pos] not in self.netlist.connections):
end_pos += 1
init = (signal.init >> pos) & ((1 << (end_pos - pos)) - 1)
cell = _nir.FlipFlop(module_idx,
data=value[pos:end_pos],
init=init,
clk=_nir.Net.from_const(0),
clk_edge="pos",
arst=_nir.Net.from_const(0),
attributes={},
src_loc=signal.src_loc,
)
ff_value = self.netlist.add_value_cell(end_pos - pos, cell)
self.connect(value[pos:end_pos], ff_value, src_loc=signal.src_loc)
pos = end_pos
def emit_undriven(self):
# Connect all undriven signal bits to their initial values. This can only happen for entirely
# undriven signals, or signals that are partially driven by instances.
for signal, value in self.netlist.signals.items():
for bit, net in enumerate(value):
if net.is_late and net not in self.netlist.connections:
self.netlist.connections[net] = _nir.Net.from_const((signal.init >> bit) & 1)
def emit_fragment(self, fragment: _ir.Fragment, parent_module_idx: 'int | None', *, cell_src_loc=None):
from . import _mem
fragment_name = self.design.fragments[fragment].name
if isinstance(fragment, _ir.Instance):
assert parent_module_idx is not None
self.emit_instance(parent_module_idx, fragment, name=fragment_name[-1])
self.fragment_module_idx[fragment] = parent_module_idx
elif isinstance(fragment, _mem.MemoryInstance):
assert parent_module_idx is not None
memory = self.emit_memory(parent_module_idx, fragment, name=fragment_name[-1])
write_ports = []
for port in fragment._write_ports:
write_ports.append(self.emit_write_port(parent_module_idx, fragment, port, memory))
for port in fragment._read_ports:
self.emit_read_port(parent_module_idx, fragment, port, memory, write_ports)
self.fragment_module_idx[fragment] = parent_module_idx
elif isinstance(fragment, _ir.IOBufferInstance):
assert parent_module_idx is not None
self.emit_iobuffer(parent_module_idx, fragment)
self.fragment_module_idx[fragment] = parent_module_idx
elif type(fragment) is _ir.Fragment:
module_idx = self.netlist.add_module(parent_module_idx, fragment_name, src_loc=fragment.src_loc, cell_src_loc=cell_src_loc)
self.fragment_module_idx[fragment] = module_idx
signal_names = self.design.fragments[fragment].signal_names
self.netlist.modules[module_idx].signal_names = signal_names
io_port_names = self.design.fragments[fragment].io_port_names
self.netlist.modules[module_idx].io_port_names = io_port_names
for signal in signal_names:
self.emit_signal(signal)
for port in io_port_names:
self.emit_io(port)
for domain, stmts in fragment.statements.items():
for stmt in stmts:
self.emit_stmt(module_idx, fragment, domain, stmt, _nir.Net.from_const(1))
for subfragment, _name, sub_src_loc in fragment.subfragments:
self.emit_fragment(subfragment, module_idx, cell_src_loc=sub_src_loc)
if parent_module_idx is None:
self.emit_drivers()
self.emit_top_ports(fragment)
if self.all_undef_to_ff:
self.emit_undef_ff()
self.emit_undriven()
else:
assert False # :nocov:
def _emit_netlist(netlist: _nir.Netlist, design, *, all_undef_to_ff=False):
NetlistEmitter(netlist, design, all_undef_to_ff=all_undef_to_ff).emit_fragment(design.fragment, None)
def _compute_net_flows(netlist: _nir.Netlist):
# Computes the net flows for all modules of the netlist.
#
# The rules for net flows are as follows:
#
# - the modules that have a given net in their net_flow form a subtree of the hierarchy
# - Internal is used in the root of the subtree and nowhere else
# - Output is used for modules that contain the definition of the net, or are on the
# path from the definition to the root
# - remaining modules have a flow of Input (unless the net is a top-level inout port,
# in which case it is Inout)
#
# In other words, the tree looks something like this:
#
# - [no flow] <<< top
# - [no flow]
# - Internal
# - Input << use
# - [no flow]
# - Input
# - Input << use
# - Output
# - Input << use
# - [no flow]
# - Output << def
# - Input
# - Input
# - [no flow]
# - [no flow]
# - [no flow]
lca = {}
# Initialize by marking the definition point of every net.
for cell_idx, cell in enumerate(netlist.cells):
for net in cell.output_nets(cell_idx):
lca[net] = cell.module_idx
netlist.modules[cell.module_idx].net_flow[net] = _nir.ModuleNetFlow.Internal
# Marks a use of a net within a given module, and adjusts its netflows in all modules
# as required.
def use_net(net, use_module):
if net.is_const:
return
# If the net is already present in the current module, we're done.
if net in netlist.modules[use_module].net_flow:
return
modules = netlist.modules
# Otherwise, we need to route the net through the hierarchy from def_module
# to use_module. We do that by treating use_module and def_module as pointers
# and moving them up the hierarchy until they meet at the new LCA.
def_module = lca[net]
# While def_module deeper than use_module, go up with def_module.
while len(modules[def_module].name) > len(modules[use_module].name):
modules[def_module].net_flow[net] = _nir.ModuleNetFlow.Output
def_module = modules[def_module].parent
# While use_module deeper than def_module, go up with use_module.
# If use_module is below def_module in the hierarchy, we may hit
# another module which already uses this net before hitting def_module,
# so check for this case.
while len(modules[def_module].name) < len(modules[use_module].name):
if net in modules[use_module].net_flow:
return
modules[use_module].net_flow[net] = _nir.ModuleNetFlow.Input
use_module = modules[use_module].parent
# Now both pointers should be at the same depth within the hierarchy.
assert len(modules[def_module].name) == len(modules[use_module].name)
# Move both pointers up until they meet.
while def_module != use_module:
modules[def_module].net_flow[net] = _nir.ModuleNetFlow.Output
def_module = modules[def_module].parent
modules[use_module].net_flow[net] = _nir.ModuleNetFlow.Input
use_module = modules[use_module].parent
assert len(modules[def_module].name) == len(modules[use_module].name)
# And mark the new LCA.
modules[def_module].net_flow[net] = _nir.ModuleNetFlow.Internal
lca[net] = def_module
# Now mark all uses and flesh out the structure.
for cell in netlist.cells:
for net in cell.input_nets():
use_net(net, cell.module_idx)
# TODO: ?
for module_idx, module in enumerate(netlist.modules):
for signal in module.signal_names:
for net in netlist.signals[signal]:
use_net(net, module_idx)
def _compute_ports(netlist: _nir.Netlist):
# Compute the indexes at which the outputs of a cell should be split to create a distinct port.
# These indexes are stored here as nets.
port_starts = set()
for start, _ in netlist.top.ports_i.values():
port_starts.add(_nir.Net.from_cell(0, start))
for cell_idx, cell in enumerate(netlist.cells):
if isinstance(cell, _nir.Instance):
for start, _ in cell.ports_o.values():
port_starts.add(_nir.Net.from_cell(cell_idx, start))
for module in netlist.modules:
# Collect preferred names for ports. If a port exactly matches a signal, we reuse
# the signal name for the port. Otherwise, we synthesize a private name.
name_table = {}
for signal, name in module.signal_names.items():
value = netlist.signals[signal]
if value not in name_table and not name.startswith('$'):
name_table[value] = name
# Gather together "adjacent" nets with the same flow into ports.
visited = set()
for net in sorted(module.net_flow):
flow = module.net_flow[net]
if flow == _nir.ModuleNetFlow.Internal:
continue
if net in visited:
continue
# We found a net that needs a port. Keep joining the next nets output by the same
# cell into the same port, if applicable, but stop at instance/top port boundaries.
nets = [net]
while True:
succ = _nir.Net.from_cell(net.cell, net.bit + 1)
if succ in port_starts:
break
if succ not in module.net_flow:
break
if module.net_flow[succ] != module.net_flow[net]:
break
net = succ
nets.append(net)
value = _nir.Value(nets)
# Joined as many nets as we could, now name and add the port.
if value in name_table:
name = name_table[value]
else:
name = f"port${value[0].cell}${value[0].bit}"
module.ports[name] = (value, flow)
visited.update(value)
# The 0th cell and the 0th module correspond to the toplevel. Transfer the net flows from
# the toplevel cell (used for data flow) to the toplevel module (used to split netlist into
# modules in the backends).
top_module = netlist.modules[0]
for name, (start, width) in netlist.top.ports_i.items():
top_module.ports[name] = (
_nir.Value(_nir.Net.from_cell(0, start + bit) for bit in range(width)),
_nir.ModuleNetFlow.Input
)
for name, value in netlist.top.ports_o.items():
top_module.ports[name] = (value, _nir.ModuleNetFlow.Output)
def _compute_ionet_dirs(netlist: _nir.Netlist):
# Collects the direction of every IO net, for every module it needs to be routed through.
for cell in netlist.cells:
for (net, dir) in cell.io_nets():
module_idx = cell.module_idx
while module_idx is not None:
netlist.modules[module_idx].ionet_dir[net] = dir
module_idx = netlist.modules[module_idx].parent
def _compute_io_ports(netlist: _nir.Netlist, ports):
io_ports = {
port: _nir.IOValue(_nir.IONet.from_port(idx, bit) for bit in range(len(port)))
for idx, port in enumerate(netlist.io_ports)
}
for module in netlist.modules:
if module.parent is None:
# Top module gets special treatment: each IOPort is added in its entirety.
for (name, port, dir) in ports:
dir = {
PortDirection.Input: _nir.IODirection.Input,
PortDirection.Output: _nir.IODirection.Output,
PortDirection.Inout: _nir.IODirection.Bidir,
None: None,
}[dir]
if not isinstance(port, _ast.IOPort):
continue
auto_dir = None
for net in io_ports[port]:
if net in module.ionet_dir:
if auto_dir is None:
auto_dir = module.ionet_dir[net]
else:
auto_dir |= module.ionet_dir[net]
if dir is None:
dir = auto_dir
if auto_dir is None:
dir = _nir.IODirection.Bidir
else:
if auto_dir is not None and (auto_dir | dir) != dir:
raise ValueError(f"Port {name} is {dir.value}, but is used as {auto_dir.value}")
module.io_ports[name] = (io_ports[port], dir)
else:
# Collect preferred names for ports. If a port exactly matches a signal, we reuse
# the signal name for the port. Otherwise, we synthesize a private name.
name_table = {}
for port, name in module.io_port_names.items():
value = io_ports[port]
if value not in name_table and not name.startswith('$'):
name_table[value] = name
# Gather together "adjacent" nets with the same flow into ports.
visited = set()
for net in sorted(module.ionet_dir):
dir = module.ionet_dir[net]
if net in visited:
continue
# We found a net that needs a port. Keep joining the next nets output by the same
# cell into the same port, if applicable, but stop at instance/top port boundaries.
nets = [net]
while True:
succ = _nir.IONet.from_port(net.port, net.bit + 1)
if succ not in module.ionet_dir:
break
if module.ionet_dir[succ] != module.ionet_dir[net]:
break
net = succ
nets.append(net)
value = _nir.IOValue(nets)
# Joined as many nets as we could, now name and add the port.
if value in name_table:
name = name_table[value]
else:
name = f"ioport${value[0].port}${value[0].bit}"
module.io_ports[name] = (value, dir)
visited.update(value)
def build_netlist(fragment, ports=(), *, name="top", all_undef_to_ff=False, **kwargs):
if isinstance(fragment, Design):
design = fragment
else:
design = fragment.prepare(ports=ports, hierarchy=(name,), **kwargs)
netlist = _nir.Netlist()
_emit_netlist(netlist, design, all_undef_to_ff=all_undef_to_ff)
netlist.resolve_all_nets()
_compute_net_flows(netlist)
_compute_ports(netlist)
_compute_ionet_dirs(netlist)
_compute_io_ports(netlist, design.ports)
return netlist