"""Generate the main interpreter switch. Reads the instruction definitions from bytecodes.c. Writes the cases to generated_cases.c.h, which is #included in ceval.c. """ import argparse from analyzer import ( Analysis, Instruction, Uop, Part, analyze_files, Skip, Flush, analysis_error, StackItem, ) from generators_common import ( DEFAULT_INPUT, ROOT, write_header, type_and_null, Emitter, ) from cwriter import CWriter from typing import TextIO from stack import Local, Stack, StackError, get_stack_effect DEFAULT_OUTPUT = ROOT / "Python/generated_cases.c.h" FOOTER = "#undef TIER_ONE\n" def declare_variable(var: StackItem, out: CWriter) -> None: type, null = type_and_null(var) space = " " if type[-1].isalnum() else "" if var.condition: out.emit(f"{type}{space}{var.name} = {null};\n") else: out.emit(f"{type}{space}{var.name};\n") def declare_variables(inst: Instruction, out: CWriter) -> None: try: stack = get_stack_effect(inst) except StackError as ex: raise analysis_error(ex.args[0], inst.where) required = set(stack.defined) required.discard("unused") for part in inst.parts: if not isinstance(part, Uop): continue for var in part.stack.inputs: if var.name in required: required.remove(var.name) declare_variable(var, out) for var in part.stack.outputs: if var.name in required: required.remove(var.name) declare_variable(var, out) def write_uop( uop: Part, emitter: Emitter, offset: int, stack: Stack, inst: Instruction, braces: bool, ) -> int: # out.emit(stack.as_comment() + "\n") if isinstance(uop, Skip): entries = "entries" if uop.size > 1 else "entry" emitter.emit(f"/* Skip {uop.size} cache {entries} */\n") return offset + uop.size if isinstance(uop, Flush): emitter.emit(f"// flush\n") stack.flush(emitter.out) return offset try: locals: dict[str, Local] = {} emitter.out.start_line() if braces: emitter.out.emit(f"// {uop.name}\n") peeks: list[Local] = [] for var in reversed(uop.stack.inputs): code, local = stack.pop(var) emitter.emit(code) if var.peek: peeks.append(local) if local.defined: locals[local.name] = local # Push back the peeks, so that they remain on the logical # stack, but their values are cached. while peeks: stack.push(peeks.pop()) if braces: emitter.emit("{\n") emitter.out.emit(stack.define_output_arrays(uop.stack.outputs)) outputs: list[Local] = [] for var in uop.stack.outputs: if not var.peek: if var.name in locals: local = locals[var.name] elif var.name == "unused": local = Local.unused(var) else: local = Local.local(var) outputs.append(local) for cache in uop.caches: if cache.name != "unused": if cache.size == 4: type = "PyObject *" reader = "read_obj" else: type = f"uint{cache.size*16}_t " reader = f"read_u{cache.size*16}" emitter.emit( f"{type}{cache.name} = {reader}(&this_instr[{offset}].cache);\n" ) if inst.family is None: emitter.emit(f"(void){cache.name};\n") offset += cache.size emitter.emit_tokens(uop, stack, inst) for output in outputs: if output.name in uop.deferred_refs.values(): # We've already spilled this when emitting tokens output.cached = False stack.push(output) if braces: emitter.out.start_line() emitter.emit("}\n") # emitter.emit(stack.as_comment() + "\n") return offset except StackError as ex: raise analysis_error(ex.args[0], uop.body[0]) def uses_this(inst: Instruction) -> bool: if inst.properties.needs_this: return True for uop in inst.parts: if not isinstance(uop, Uop): continue for cache in uop.caches: if cache.name != "unused": return True return False def generate_tier1( filenames: list[str], analysis: Analysis, outfile: TextIO, lines: bool ) -> None: write_header(__file__, filenames, outfile) outfile.write( """ #ifdef TIER_TWO #error "This file is for Tier 1 only" #endif #define TIER_ONE 1 """ ) out = CWriter(outfile, 2, lines) emitter = Emitter(out) out.emit("\n") for name, inst in sorted(analysis.instructions.items()): needs_this = uses_this(inst) out.emit("\n") out.emit(f"TARGET({name}) {{\n") unused_guard = "(void)this_instr;\n" if inst.family is None else "" if inst.properties.needs_prev: out.emit(f"_Py_CODEUNIT *prev_instr = frame->instr_ptr;\n") if needs_this and not inst.is_target: out.emit(f"_Py_CODEUNIT *this_instr = frame->instr_ptr = next_instr;\n") out.emit(unused_guard) else: out.emit(f"frame->instr_ptr = next_instr;\n") out.emit(f"next_instr += {inst.size};\n") out.emit(f"INSTRUCTION_STATS({name});\n") if inst.is_target: out.emit(f"PREDICTED({name});\n") if needs_this: out.emit(f"_Py_CODEUNIT *this_instr = next_instr - {inst.size};\n") out.emit(unused_guard) if inst.family is not None: out.emit( f"static_assert({inst.family.size} == {inst.size-1}" ', "incorrect cache size");\n' ) declare_variables(inst, out) offset = 1 # The instruction itself stack = Stack() for part in inst.parts: # Only emit braces if more than one uop insert_braces = len([p for p in inst.parts if isinstance(p, Uop)]) > 1 offset = write_uop(part, emitter, offset, stack, inst, insert_braces) out.start_line() if not inst.parts[-1].properties.always_exits: stack.flush(out) out.emit("DISPATCH();\n") out.start_line() out.emit("}") out.emit("\n") outfile.write(FOOTER) arg_parser = argparse.ArgumentParser( description="Generate the code for the interpreter switch.", formatter_class=argparse.ArgumentDefaultsHelpFormatter, ) arg_parser.add_argument( "-o", "--output", type=str, help="Generated code", default=DEFAULT_OUTPUT ) arg_parser.add_argument( "-l", "--emit-line-directives", help="Emit #line directives", action="store_true" ) arg_parser.add_argument( "input", nargs=argparse.REMAINDER, help="Instruction definition file(s)" ) def generate_tier1_from_files( filenames: list[str], outfilename: str, lines: bool ) -> None: data = analyze_files(filenames) with open(outfilename, "w") as outfile: generate_tier1(filenames, data, outfile, lines) if __name__ == "__main__": args = arg_parser.parse_args() if len(args.input) == 0: args.input.append(DEFAULT_INPUT) data = analyze_files(args.input) with open(args.output, "w") as outfile: generate_tier1(args.input, data, outfile, args.emit_line_directives)