cpython/Tools/jit/_writer.py

80 lines
3.0 KiB
Python

"""Utilities for writing StencilGroups out to a C header file."""
import itertools
import typing
import math
import _stencils
def _dump_footer(
groups: dict[str, _stencils.StencilGroup], symbols: dict[str, int]
) -> typing.Iterator[str]:
symbol_mask_size = max(math.ceil(len(symbols) / 32), 1)
yield f'static_assert(SYMBOL_MASK_WORDS >= {symbol_mask_size}, "SYMBOL_MASK_WORDS too small");'
yield ""
yield "typedef struct {"
yield " void (*emit)("
yield " unsigned char *code, unsigned char *data, _PyExecutorObject *executor,"
yield " const _PyUOpInstruction *instruction, jit_state *state);"
yield " size_t code_size;"
yield " size_t data_size;"
yield " symbol_mask trampoline_mask;"
yield "} StencilGroup;"
yield ""
yield f"static const StencilGroup trampoline = {groups['trampoline'].as_c('trampoline')};"
yield ""
yield "static const StencilGroup stencil_groups[MAX_UOP_ID + 1] = {"
for opname, group in sorted(groups.items()):
if opname == "trampoline":
continue
yield f" [{opname}] = {group.as_c(opname)},"
yield "};"
yield ""
yield f"static const void * const symbols_map[{max(len(symbols), 1)}] = {{"
for symbol, ordinal in symbols.items():
yield f" [{ordinal}] = &{symbol},"
yield "};"
def _dump_stencil(opname: str, group: _stencils.StencilGroup) -> typing.Iterator[str]:
yield "void"
yield f"emit_{opname}("
yield " unsigned char *code, unsigned char *data, _PyExecutorObject *executor,"
yield " const _PyUOpInstruction *instruction, jit_state *state)"
yield "{"
for part, stencil in [("code", group.code), ("data", group.data)]:
for line in stencil.disassembly:
yield f" // {line}"
if stencil.body:
yield f" const unsigned char {part}_body[{len(stencil.body)}] = {{"
for i in range(0, len(stencil.body), 8):
row = " ".join(f"{byte:#04x}," for byte in stencil.body[i : i + 8])
yield f" {row}"
yield " };"
# Data is written first (so relaxations in the code work properly):
for part, stencil in [("data", group.data), ("code", group.code)]:
if stencil.body:
yield f" memcpy({part}, {part}_body, sizeof({part}_body));"
skip = False
stencil.holes.sort(key=lambda hole: hole.offset)
for hole, pair in itertools.zip_longest(stencil.holes, stencil.holes[1:]):
if skip:
skip = False
continue
if pair and (folded := hole.fold(pair)):
skip = True
hole = folded
yield f" {hole.as_c(part)}"
yield "}"
yield ""
def dump(
groups: dict[str, _stencils.StencilGroup], symbols: dict[str, int]
) -> typing.Iterator[str]:
"""Yield a JIT compiler line-by-line as a C header file."""
for opname, group in sorted(groups.items()):
yield from _dump_stencil(opname, group)
yield from _dump_footer(groups, symbols)