cpython/Tools/cases_generator/analysis.py

416 lines
16 KiB
Python

import re
import sys
import typing
from _typing_backports import assert_never
from flags import InstructionFlags, variable_used
from formatting import prettify_filename, UNUSED
from instructions import (
ActiveCacheEffect,
Component,
Instruction,
InstructionOrCacheEffect,
MacroInstruction,
MacroParts,
OverriddenInstructionPlaceHolder,
PseudoInstruction,
)
import parsing
from parsing import StackEffect
BEGIN_MARKER = "// BEGIN BYTECODES //"
END_MARKER = "// END BYTECODES //"
RESERVED_WORDS = {
"co_consts": "Use FRAME_CO_CONSTS.",
"co_names": "Use FRAME_CO_NAMES.",
}
RE_PREDICTED = r"^\s*(?:GO_TO_INSTRUCTION\(|DEOPT_IF\(.*?,\s*)(\w+)\);\s*(?://.*)?$"
class Analyzer:
"""Parse input, analyze it, and write to output."""
input_filenames: list[str]
errors: int = 0
warnings: int = 0
def __init__(self, input_filenames: list[str]):
self.input_filenames = input_filenames
def message(self, msg: str, node: parsing.Node) -> None:
lineno = 0
filename = "<unknown file>"
if context := node.context:
filename = context.owner.filename
# Use line number of first non-comment in the node
for token in context.owner.tokens[context.begin : context.end]:
lineno = token.line
if token.kind != "COMMENT":
break
print(f"{filename}:{lineno}: {msg}", file=sys.stderr)
def error(self, msg: str, node: parsing.Node) -> None:
self.message("error: " + msg, node)
self.errors += 1
def warning(self, msg: str, node: parsing.Node) -> None:
self.message("warning: " + msg, node)
self.warnings += 1
def note(self, msg: str, node: parsing.Node) -> None:
self.message("note: " + msg, node)
everything: list[
parsing.InstDef
| parsing.Macro
| parsing.Pseudo
| OverriddenInstructionPlaceHolder
]
instrs: dict[str, Instruction] # Includes ops
macros: dict[str, parsing.Macro]
macro_instrs: dict[str, MacroInstruction]
families: dict[str, parsing.Family]
pseudos: dict[str, parsing.Pseudo]
pseudo_instrs: dict[str, PseudoInstruction]
def parse(self) -> None:
"""Parse the source text.
We only want the parser to see the stuff between the
begin and end markers.
"""
self.everything = []
self.instrs = {}
self.macros = {}
self.families = {}
self.pseudos = {}
instrs_idx: dict[str, int] = dict()
for filename in self.input_filenames:
self.parse_file(filename, instrs_idx)
files = " + ".join(self.input_filenames)
n_instrs = 0
n_ops = 0
for instr in self.instrs.values():
if instr.kind == "op":
n_ops += 1
else:
n_instrs += 1
print(
f"Read {n_instrs} instructions, {n_ops} ops, "
f"{len(self.macros)} macros, {len(self.pseudos)} pseudos, "
f"and {len(self.families)} families from {files}",
file=sys.stderr,
)
def parse_file(self, filename: str, instrs_idx: dict[str, int]) -> None:
with open(filename) as file:
src = file.read()
psr = parsing.Parser(src, filename=prettify_filename(filename))
# Skip until begin marker
while tkn := psr.next(raw=True):
if tkn.text == BEGIN_MARKER:
break
else:
raise psr.make_syntax_error(
f"Couldn't find {BEGIN_MARKER!r} in {psr.filename}"
)
start = psr.getpos()
# Find end marker, then delete everything after it
while tkn := psr.next(raw=True):
if tkn.text == END_MARKER:
break
del psr.tokens[psr.getpos() - 1 :]
# Parse from start
psr.setpos(start)
thing: parsing.Node | None
thing_first_token = psr.peek()
while thing := psr.definition():
thing = typing.cast(
parsing.InstDef | parsing.Macro | parsing.Pseudo | parsing.Family, thing
)
if ws := [w for w in RESERVED_WORDS if variable_used(thing, w)]:
self.error(
f"'{ws[0]}' is a reserved word. {RESERVED_WORDS[ws[0]]}", thing
)
match thing:
case parsing.InstDef(name=name):
if name in self.instrs:
if not thing.override:
raise psr.make_syntax_error(
f"Duplicate definition of '{name}' @ {thing.context} "
f"previous definition @ {self.instrs[name].inst.context}",
thing_first_token,
)
self.everything[
instrs_idx[name]
] = OverriddenInstructionPlaceHolder(name=name)
if name not in self.instrs and thing.override:
raise psr.make_syntax_error(
f"Definition of '{name}' @ {thing.context} is supposed to be "
"an override but no previous definition exists.",
thing_first_token,
)
self.instrs[name] = Instruction(thing)
instrs_idx[name] = len(self.everything)
self.everything.append(thing)
case parsing.Macro(name):
self.macros[name] = thing
self.everything.append(thing)
case parsing.Family(name):
self.families[name] = thing
case parsing.Pseudo(name):
self.pseudos[name] = thing
self.everything.append(thing)
case _:
assert_never(thing)
if not psr.eof():
raise psr.make_syntax_error(f"Extra stuff at the end of {filename}")
def analyze(self) -> None:
"""Analyze the inputs.
Raises SystemExit if there is an error.
"""
self.analyze_macros_and_pseudos()
self.find_predictions()
self.map_families()
self.check_families()
def find_predictions(self) -> None:
"""Find the instructions that need PREDICTED() labels."""
for instr in self.instrs.values():
targets: set[str] = set()
for line in instr.block_text:
if m := re.match(RE_PREDICTED, line):
targets.add(m.group(1))
for target in targets:
if target_instr := self.instrs.get(target):
target_instr.predicted = True
elif target_macro := self.macro_instrs.get(target):
target_macro.predicted = True
else:
self.error(
f"Unknown instruction {target!r} predicted in {instr.name!r}",
instr.inst, # TODO: Use better location
)
def map_families(self) -> None:
"""Link instruction names back to their family, if they have one."""
for family in self.families.values():
for member in [family.name] + family.members:
if member_instr := self.instrs.get(member):
if (
member_instr.family is not family
and member_instr.family is not None
):
self.error(
f"Instruction {member} is a member of multiple families "
f"({member_instr.family.name}, {family.name}).",
family,
)
else:
member_instr.family = family
elif not self.macro_instrs.get(member):
self.error(
f"Unknown instruction {member!r} referenced in family {family.name!r}",
family,
)
def check_families(self) -> None:
"""Check each family:
- Must have at least 2 members (including head)
- Head and all members must be known instructions
- Head and all members must have the same cache, input and output effects
"""
for family in self.families.values():
if family.name not in self.macro_instrs and family.name not in self.instrs:
self.error(
f"Family {family.name!r} has unknown instruction {family.name!r}",
family,
)
members = [
member
for member in family.members
if member in self.instrs or member in self.macro_instrs
]
if members != family.members:
unknown = set(family.members) - set(members)
self.error(
f"Family {family.name!r} has unknown members: {unknown}", family
)
expected_effects = self.effect_counts(family.name)
for member in members:
member_effects = self.effect_counts(member)
if member_effects != expected_effects:
self.error(
f"Family {family.name!r} has inconsistent "
f"(cache, input, output) effects:\n"
f" {family.name} = {expected_effects}; "
f"{member} = {member_effects}",
family,
)
def effect_counts(self, name: str) -> tuple[int, int, int]:
if instr := self.instrs.get(name):
cache = instr.cache_offset
input = len(instr.input_effects)
output = len(instr.output_effects)
elif mac := self.macro_instrs.get(name):
cache = mac.cache_offset
input, output = 0, 0
for part in mac.parts:
if isinstance(part, Component):
# A component may pop what the previous component pushed,
# so we offset the input/output counts by that.
delta_i = len(part.instr.input_effects)
delta_o = len(part.instr.output_effects)
offset = min(delta_i, output)
input += delta_i - offset
output += delta_o - offset
else:
assert False, f"Unknown instruction {name!r}"
return cache, input, output
def analyze_macros_and_pseudos(self) -> None:
"""Analyze each macro and pseudo instruction."""
self.macro_instrs = {}
self.pseudo_instrs = {}
for name, macro in self.macros.items():
self.macro_instrs[name] = mac = self.analyze_macro(macro)
self.check_macro_consistency(mac)
for name, pseudo in self.pseudos.items():
self.pseudo_instrs[name] = self.analyze_pseudo(pseudo)
# TODO: Merge with similar code in stacking.py, write_components()
def check_macro_consistency(self, mac: MacroInstruction) -> None:
def get_var_names(instr: Instruction) -> dict[str, StackEffect]:
vars: dict[str, StackEffect] = {}
for eff in instr.input_effects + instr.output_effects:
if eff.name == UNUSED:
continue
if eff.name in vars:
if vars[eff.name] != eff:
self.error(
f"Instruction {instr.name!r} has "
f"inconsistent type/cond/size for variable "
f"{eff.name!r}: {vars[eff.name]} vs {eff}",
instr.inst,
)
else:
vars[eff.name] = eff
return vars
all_vars: dict[str, StackEffect] = {}
# print("Checking", mac.name)
prevop: Instruction | None = None
for part in mac.parts:
if not isinstance(part, Component):
continue
vars = get_var_names(part.instr)
# print(" //", part.instr.name, "//", vars)
for name, eff in vars.items():
if name in all_vars:
if all_vars[name] != eff:
self.error(
f"Macro {mac.name!r} has "
f"inconsistent type/cond/size for variable "
f"{name!r}: "
f"{all_vars[name]} vs {eff} in {part.instr.name!r}",
mac.macro,
)
else:
all_vars[name] = eff
if prevop is not None:
pushes = list(prevop.output_effects)
pops = list(reversed(part.instr.input_effects))
copies: list[tuple[StackEffect, StackEffect]] = []
while pushes and pops and pushes[-1] == pops[0]:
src, dst = pushes.pop(), pops.pop(0)
if src.name == dst.name or dst.name == UNUSED:
continue
copies.append((src, dst))
reads = set(copy[0].name for copy in copies)
writes = set(copy[1].name for copy in copies)
if reads & writes:
self.error(
f"Macro {mac.name!r} has conflicting copies "
f"(source of one copy is destination of another): "
f"{reads & writes}",
mac.macro,
)
prevop = part.instr
def analyze_macro(self, macro: parsing.Macro) -> MacroInstruction:
components = self.check_macro_components(macro)
parts: MacroParts = []
flags = InstructionFlags.newEmpty()
offset = 0
for component in components:
match component:
case parsing.CacheEffect() as ceffect:
parts.append(ceffect)
offset += ceffect.size
case Instruction() as instr:
part, offset = self.analyze_instruction(instr, offset)
parts.append(part)
if instr.name != "SAVE_IP":
# SAVE_IP in a macro is a no-op in Tier 1
flags.add(instr.instr_flags)
case _:
assert_never(component)
format = "IB" if flags.HAS_ARG_FLAG else "IX"
if offset:
format += "C" + "0" * (offset - 1)
return MacroInstruction(macro.name, format, flags, macro, parts, offset)
def analyze_pseudo(self, pseudo: parsing.Pseudo) -> PseudoInstruction:
targets = [self.instrs[target] for target in pseudo.targets]
assert targets
# Make sure the targets have the same fmt
fmts = list(set([t.instr_fmt for t in targets]))
assert len(fmts) == 1
ignored_flags = {'HAS_EVAL_BREAK_FLAG'}
assert len({t.instr_flags.bitmap(ignore=ignored_flags) for t in targets}) == 1
return PseudoInstruction(pseudo.name, targets, fmts[0], targets[0].instr_flags)
def analyze_instruction(
self, instr: Instruction, offset: int
) -> tuple[Component, int]:
active_effects: list[ActiveCacheEffect] = []
for ceffect in instr.cache_effects:
if ceffect.name != UNUSED:
active_effects.append(ActiveCacheEffect(ceffect, offset))
offset += ceffect.size
return (
Component(instr, active_effects),
offset,
)
def check_macro_components(
self, macro: parsing.Macro
) -> list[InstructionOrCacheEffect]:
components: list[InstructionOrCacheEffect] = []
for uop in macro.uops:
match uop:
case parsing.OpName(name):
if name not in self.instrs:
self.error(f"Unknown instruction {name!r}", macro)
components.append(self.instrs[name])
case parsing.CacheEffect():
components.append(uop)
case _:
assert_never(uop)
return components