diff --git a/tests/perf_bench/bm_fft.py b/tests/perf_bench/bm_fft.py new file mode 100644 index 000000000..9ea8b08f4 --- /dev/null +++ b/tests/perf_bench/bm_fft.py @@ -0,0 +1,69 @@ +# Copyright (c) 2019 Project Nayuki. (MIT License) +# https://www.nayuki.io/page/free-small-fft-in-multiple-languages + +import math, cmath + +def transform_radix2(vector, inverse): + # Returns the integer whose value is the reverse of the lowest 'bits' bits of the integer 'x'. + def reverse(x, bits): + y = 0 + for i in range(bits): + y = (y << 1) | (x & 1) + x >>= 1 + return y + + # Initialization + n = len(vector) + levels = int(math.log2(n)) + coef = (2 if inverse else -2) * cmath.pi / n + exptable = [cmath.rect(1, i * coef) for i in range(n // 2)] + vector = [vector[reverse(i, levels)] for i in range(n)] # Copy with bit-reversed permutation + + # Radix-2 decimation-in-time FFT + size = 2 + while size <= n: + halfsize = size // 2 + tablestep = n // size + for i in range(0, n, size): + k = 0 + for j in range(i, i + halfsize): + temp = vector[j + halfsize] * exptable[k] + vector[j + halfsize] = vector[j] - temp + vector[j] += temp + k += tablestep + size *= 2 + return vector + +########################################################################### +# Benchmark interface + +bm_params = { + (50, 25): (2, 128), + (100, 100): (3, 256), + (1000, 1000): (20, 512), + (5000, 1000): (100, 512), +} + +def bm_setup(params): + state = None + signal = [math.cos(2 * math.pi * i / params[1]) + 0j for i in range(params[1])] + fft = None + fft_inv = None + + def run(): + nonlocal fft, fft_inv + for _ in range(params[0]): + fft = transform_radix2(signal, False) + fft_inv = transform_radix2(fft, True) + + def result(): + nonlocal fft, fft_inv + fft[1] -= 0.5 * params[1] + fft[-1] -= 0.5 * params[1] + fft_ok = all(abs(f) < 1e-3 for f in fft) + for i in range(len(fft_inv)): + fft_inv[i] -= params[1] * signal[i] + fft_inv_ok = all(abs(f) < 1e-3 for f in fft_inv) + return params[0] * params[1], (fft_ok, fft_inv_ok) + + return run, result