#!/usr/bin/env python3 """Generate cycle-accurate golden vectors for the streaming 5-point stencil benchmark.""" from __future__ import annotations from dataclasses import dataclass import random TILE_ROWS = 8 TILE_COLS = 8 @dataclass(frozen=True) class Cycle: tag: str rst: int in_valid: int tile_start: int sample: int | None def to_twos(value: int, width: int) -> int: return value & ((1 << width) - 1) def constant_tile(value: int) -> list[list[int]]: return [[value for _ in range(TILE_COLS)] for _ in range(TILE_ROWS)] def affine_tile(a_r: int, a_c: int, bias: int) -> list[list[int]]: return [[a_r * r + a_c * c + bias for c in range(TILE_COLS)] for r in range(TILE_ROWS)] def impulse_tile(row: int, col: int, value: int) -> list[list[int]]: tile = constant_tile(0) tile[row][col] = value return tile def border_activity_tile() -> list[list[int]]: tile = constant_tile(0) for c in range(TILE_COLS): tile[0][c] = 40 - 3 * c for r in range(TILE_ROWS): tile[r][7] = -20 + 5 * r tile[7][1] = 27 tile[6][0] = -31 return tile def extreme_tile() -> list[list[int]]: return [[127 if ((r + c) % 2 == 0) else -128 for c in range(TILE_COLS)] for r in range(TILE_ROWS)] def random_tile(seed: int) -> list[list[int]]: rng = random.Random(seed) return [[rng.randint(-128, 127) for _ in range(TILE_COLS)] for _ in range(TILE_ROWS)] def append_idle(seq: list[Cycle], tag: str, count: int = 1) -> None: for idx in range(count): seq.append(Cycle(f"{tag}_idle{idx}", 0, 0, 0, None)) def append_reset(seq: list[Cycle], tag: str, count: int = 1, ignored_sample: int | None = None) -> None: for idx in range(count): in_valid = 1 if (ignored_sample is not None and idx == 0) else 0 tile_start = 1 if in_valid else 0 sample = ignored_sample if in_valid else None seq.append(Cycle(f"{tag}_rst{idx}", 1, in_valid, tile_start, sample)) def append_tile( seq: list[Cycle], tile: list[list[int]], tag: str, bubble_before: set[int] | None = None, accepted_limit: int | None = None, ) -> None: accepted = 0 bubble_before = bubble_before or set() for r in range(TILE_ROWS): for c in range(TILE_COLS): if accepted_limit is not None and accepted >= accepted_limit: return while accepted in bubble_before: seq.append(Cycle(f"{tag}_gap{accepted}", 0, 0, 0, None)) bubble_before.remove(accepted) seq.append( Cycle( tag=f"{tag}_{accepted:02d}", rst=0, in_valid=1, tile_start=1 if accepted == 0 else 0, sample=tile[r][c], ) ) accepted += 1 def stencil_value(tile: list[list[int]], center_r: int, center_c: int) -> int: return ( tile[center_r - 1][center_c] + tile[center_r + 1][center_c] + tile[center_r][center_c - 1] + tile[center_r][center_c + 1] - 4 * tile[center_r][center_c] ) def expected_outputs_for_tile(tile: list[list[int]]) -> list[int]: outputs: list[int] = [] for center_r in range(1, 7): for center_c in range(1, 7): outputs.append(stencil_value(tile, center_r, center_c)) return outputs def build_sequence() -> list[Cycle]: seq: list[Cycle] = [] append_reset(seq, "startup", count=1) append_reset(seq, "reset_ignore", count=1, ignored_sample=91) append_idle(seq, "post_reset", count=1) append_tile(seq, constant_tile(23), "const23") append_tile(seq, affine_tile(3, -2, 5), "affine") append_tile(seq, impulse_tile(3, 4, 7), "posimp", bubble_before={5, 17, 34, 51}) append_tile(seq, impulse_tile(2, 2, -9), "negimp") append_tile(seq, border_activity_tile(), "border") append_tile(seq, extreme_tile(), "flush_partial", accepted_limit=22) seq.append(Cycle("flush_reset", 1, 0, 0, None)) append_idle(seq, "post_flush", count=1) append_tile(seq, random_tile(52052), "random0") append_idle(seq, "drain", count=3) return seq def simulate(sequence: list[Cycle]) -> list[tuple[int, int]]: tile = [[0 for _ in range(TILE_COLS)] for _ in range(TILE_ROWS)] sample_idx = 0 pending: dict[int, int] = {} outputs: list[tuple[int, int]] = [] for cycle_idx, cycle in enumerate(sequence): if cycle.rst: sample_idx = 0 pending.clear() tile = [[0 for _ in range(TILE_COLS)] for _ in range(TILE_ROWS)] outputs.append((0, 0)) continue outputs.append((1, pending.pop(cycle_idx))) if cycle_idx in pending else outputs.append((0, 0)) if not cycle.in_valid: continue if cycle.tile_start: sample_idx = 0 tile = [[0 for _ in range(TILE_COLS)] for _ in range(TILE_ROWS)] assert cycle.sample is not None row = sample_idx // TILE_COLS col = sample_idx % TILE_COLS tile[row][col] = cycle.sample if row >= 2 and col >= 2: center_r = row - 1 center_c = col - 1 pending[cycle_idx + 1] = stencil_value(tile, center_r, center_c) sample_idx = 0 if sample_idx == (TILE_ROWS * TILE_COLS - 1) else sample_idx + 1 return outputs def emit_verilog(sequence: list[Cycle], outputs: list[tuple[int, int]]) -> str: lines: list[str] = [] lines.append("// Generated by generate_golden.py. Do not edit by hand.") lines.append(f"localparam integer NUM_TESTS = {len(sequence)};") lines.append("reg test_rst [0:NUM_TESTS-1];") lines.append("reg test_in_valid [0:NUM_TESTS-1];") lines.append("reg test_tile_start [0:NUM_TESTS-1];") lines.append("reg signed [7:0] test_sample_in [0:NUM_TESTS-1];") lines.append("reg expected_out_valid [0:NUM_TESTS-1];") lines.append("reg signed [10:0] expected_stencil_out [0:NUM_TESTS-1];") lines.append("reg [255:0] test_tag [0:NUM_TESTS-1];") lines.append("") lines.append("initial begin") for idx, (cycle, (exp_valid, exp_value)) in enumerate(zip(sequence, outputs)): sample = 0 if cycle.sample is None else cycle.sample lines.append(f" test_rst[{idx}] = 1'b{cycle.rst};") lines.append(f" test_in_valid[{idx}] = 1'b{cycle.in_valid};") lines.append(f" test_tile_start[{idx}] = 1'b{cycle.tile_start};") lines.append(f" test_sample_in[{idx}] = 8'sh{to_twos(sample, 8):02x};") lines.append(f" expected_out_valid[{idx}] = 1'b{exp_valid};") lines.append(f" expected_stencil_out[{idx}] = 11'sh{to_twos(exp_value, 11):03x};") lines.append(f' test_tag[{idx}] = "{cycle.tag}";') lines.append("end") return "\n".join(lines) def self_check() -> None: const_outputs = expected_outputs_for_tile(constant_tile(23)) assert len(const_outputs) == 36 assert all(value == 0 for value in const_outputs) plane_outputs = expected_outputs_for_tile(affine_tile(3, -2, 5)) assert all(value == 0 for value in plane_outputs) impulse_outputs = expected_outputs_for_tile(impulse_tile(3, 4, 7)) nonzero = {idx: value for idx, value in enumerate(impulse_outputs) if value != 0} expected_nonzero = { (2 * 6 + 3): -28, (1 * 6 + 3): 7, (3 * 6 + 3): 7, (2 * 6 + 2): 7, (2 * 6 + 4): 7, } assert nonzero == expected_nonzero def main() -> None: self_check() sequence = build_sequence() outputs = simulate(sequence) print(emit_verilog(sequence, outputs)) if __name__ == "__main__": main()