faiss/benchs/bench_partition.py
Matthijs Douze 6d0bc58db6 Implementation of PQ4 search with SIMD instructions (#1542)
Summary:
IndexPQ and IndexIVFPQ implementations with AVX shuffle instructions.

The training and computing of the codes does not change wrt. the original PQ versions but the code layout is "packed" so that it can be used efficiently by the SIMD computation kernels.

The main changes are:

- new IndexPQFastScan and IndexIVFPQFastScan objects

- simdib.h for an abstraction above the AVX2 intrinsics

- BlockInvertedLists for invlists that are 32-byte aligned and where codes are not sequential

- pq4_fast_scan.h/.cpp:  for packing codes and look-up tables + optmized distance comptuation kernels

- simd_result_hander.h: SIMD version of result collection in heaps / reservoirs

Misc changes:

- added contrib.inspect_tools to access fields in C++ objects

- moved .h and .cpp code for inverted lists to an invlists/ subdirectory, and made a .h/.cpp for InvertedListsIOHook

- added a new inverted lists type with 32-byte aligned codes (for consumption by SIMD)

- moved Windows-specific intrinsics to platfrom_macros.h

Pull Request resolved: https://github.com/facebookresearch/faiss/pull/1542

Test Plan:
```
buck test mode/opt  -j 4  //faiss/tests/:test_fast_scan_ivf //faiss/tests/:test_fast_scan
buck test mode/opt  //faiss/manifold/...
```

Reviewed By: wickedfoo

Differential Revision: D25175439

Pulled By: mdouze

fbshipit-source-id: ad1a40c0df8c10f4b364bdec7172e43d71b56c34
2020-12-03 10:06:38 -08:00

75 lines
2.0 KiB
Python

import time
import faiss
import numpy as np
def do_partition(n, qin, maxval=65536, seed=123, id_type='int64'):
print(
f"n={n} qin={qin} maxval={maxval} id_type={id_type} ",
end="\t", flush=True
)
# print("seed=", seed)
rs = np.random.RandomState(seed)
vals = rs.randint(maxval, size=n).astype('uint16')
ids = (rs.permutation(n) + 12345).astype(id_type)
sp = faiss.swig_ptr
tab_a = faiss.AlignedTableUint16()
faiss.copy_array_to_AlignedTable(vals, tab_a)
nrun = 2000
times = []
nerr = 0
stats = faiss.cvar.partition_stats
stats.reset()
for _run in range(nrun):
faiss.copy_array_to_AlignedTable(vals, tab_a)
t0 = time.time()
# print("tab a type", tab_a.get())
if type(qin) == int:
q = qin
faiss.CMax_uint16_partition_fuzzy(
tab_a.get(), sp(ids), n, q, q, None)
else:
q_min, q_max = qin
q = np.array([-1], dtype='uint64')
thresh2 = faiss.CMax_uint16_partition_fuzzy(
tab_a.get(), sp(ids), n,
q_min, q_max, sp(q)
)
q = q[0]
if not (q_min <= q <= q_max):
nerr += 1
t1 = time.time()
times.append(t1 - t0)
times = np.array(times[100:]) * 1000000
print(
f"times {times.mean():.3f} µs (± {times.std():.4f} µs) nerr={nerr} "
f"bissect {stats.bissect_cycles / 1e6:.3f} Mcy "
f"compress {stats.compress_cycles / 1e6:.3f} Mcy"
)
do_partition(200, (100, 100))
do_partition(200, (100, 150))
do_partition(2000, (1000, 1000))
do_partition(2000, (1000, 1500))
do_partition(20000, (10000, 10000))
do_partition(20000, (10000, 15000))
do_partition(200, (100, 100), id_type='int32')
do_partition(200, (100, 150), id_type='int32')
do_partition(2000, (1000, 1000), id_type='int32')
do_partition(2000, (1000, 1500), id_type='int32')
do_partition(20000, (10000, 10000), id_type='int32')
do_partition(20000, (10000, 15000), id_type='int32')