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| author | Julian Taylor <juliantaylor108@gmail.com> | 2019-05-12 20:47:52 +0200 |
|---|---|---|
| committer | Julian Taylor <juliantaylor108@gmail.com> | 2019-05-12 22:40:51 +0200 |
| commit | fdfd8b512d49f9f627d5aa7c0813543f19d8faf4 (patch) | |
| tree | 546085a86563b56ad9978362983d1f7f79c4106e | |
| parent | 886da7998d0cdc115cd010671a904390a7275810 (diff) | |
| download | numpy-fdfd8b512d49f9f627d5aa7c0813543f19d8faf4.tar.gz | |
MAINT: convert lookup table generation to byte wise loop
That way we do not need to take care of endianess when creating the
table via integers.
| -rw-r--r-- | numpy/core/src/multiarray/compiled_base.c | 43 |
1 files changed, 13 insertions, 30 deletions
diff --git a/numpy/core/src/multiarray/compiled_base.c b/numpy/core/src/multiarray/compiled_base.c index b1c457cb4..3519c7e7e 100644 --- a/numpy/core/src/multiarray/compiled_base.c +++ b/numpy/core/src/multiarray/compiled_base.c @@ -1704,8 +1704,8 @@ static PyObject * unpack_bits(PyObject *input, int axis, PyObject *count_obj, char order) { static int unpack_init = 0; - static npy_uint64 unpack_lookup_l[256]; - static npy_uint64 unpack_lookup_b[256]; + static npy_uint8 unpack_lookup_l[256][8]; + static npy_uint8 unpack_lookup_b[256][8]; PyArrayObject *inp; PyArrayObject *new = NULL; PyArrayObject *out = NULL; @@ -1792,36 +1792,19 @@ unpack_bits(PyObject *input, int axis, PyObject *count_obj, char order) } /* - * setup lookup table under GIL, 256 64 bit integers - * one integer represents 8 bits expanded to 0/1 bytes + * setup lookup table under GIL, 256 8 byte blocks representing 8 bits + * expanded to 1/0 bytes */ if (unpack_init == 0) { - npy_uint64 j; + npy_intp j; for (j=0; j < 256; j++) { - npy_uint64 v_b = 0; - npy_uint64 v_l; - v_b |= (npy_uint64)((j & 1) == 1) << 56; - v_b |= (npy_uint64)((j & 2) == 2) << 48; - v_b |= (npy_uint64)((j & 4) == 4) << 40; - v_b |= (npy_uint64)((j & 8) == 8) << 32; - v_b |= (npy_uint64)((j & 16) == 16) << 24; - v_b |= (npy_uint64)((j & 32) == 32) << 16; - v_b |= (npy_uint64)((j & 64) == 64) << 8; - v_b |= (npy_uint64)((j & 128) == 128); - - /* for bitorder little the lookup table is just byte swapped */ - v_l = npy_bswap8(v_b); - -#if NPY_BYTE_ORDER == NPY_BIG_ENDIAN - /* - * the byte pattern must be fixed on all platforms so bigendian has - * to be swapped - */ - v_l = npy_bswap8(v_l); - v_b = npy_bswap8(v_b); -#endif - unpack_lookup_b[j] = v_b; - unpack_lookup_l[j] = v_l; + npy_intp k; + for (k=0; k < 8; k++) { + npy_uint8 v = (j & (1 << k)) == (1 << k); + unpack_lookup_b[j][7 - k] = v; + /* for bitorder little the lookup table is byte swapped */ + unpack_lookup_l[j][k] = v; + } } unpack_init = 1; } @@ -1849,7 +1832,7 @@ unpack_bits(PyObject *input, int axis, PyObject *count_obj, char order) char *outptr = PyArray_ITER_DATA(ot); if (out_stride == 1) { - const npy_uint64 * const unpack_lookup = (order == 'b') ? + const npy_uint8 (*unpack_lookup)[8] = (order == 'b') ? unpack_lookup_b : unpack_lookup_l; /* for unity stride we can just copy out of the lookup table */ for (index = 0; index < in_n; index++) { |