{ "name": "loop_106", "op_type": "loop_106", "description": "Partition a vector by bit flag, concentrating set-bit elements to one side", "tags": [ "simd-loop" ], "axes": { "n": { "type": "var", "description": "axis n" } }, "inputs": { "a": { "shape": [ "n" ], "dtype": "uint32" } }, "outputs": { "b": { "shape": [ "n" ], "dtype": "uint32", "description": "Output array" } }, "reference": "import numpy as np\n\n_M = 0xFFFFFFFF\n\ndef _popcount(x):\n return bin(x & _M).count('1')\n\ndef _compress(x, m):\n x &= m\n mk = (~m << 1) & _M\n for i in range(5):\n mp = (mk ^ (mk << 1)) & _M\n mp = (mp ^ (mp << 2)) & _M\n mp = (mp ^ (mp << 4)) & _M\n mp = (mp ^ (mp << 8)) & _M\n mp = (mp ^ (mp << 16)) & _M\n mv = mp & m\n m = (m ^ mv) | (mv >> (1 << i))\n t = x & mv\n x = (x ^ t) | (t >> (1 << i))\n mk &= (~mp) & _M\n return x & _M\n\ndef _sag(x, m):\n return (((_compress(x, m) << _popcount(m)) & _M) | _compress(x, (~m) & _M)) & _M\n\n_PC = [0xaaaaaaaa, 0xcccccccc, 0x0f0f0f0f, 0x0ff00ff0, 0x0ffff000]\n_P = [_PC[0], _sag(_PC[1], _PC[0]), _sag(_PC[2], _PC[0]),\n _sag(_PC[3], _PC[0]), _sag(_PC[4], _PC[0])]\n\ndef _permute(x):\n for pi in _P:\n x = _sag(x, pi)\n return x\n\ndef run(a):\n return np.array([_permute(int(v)) for v in a], dtype=np.uint32)\n", "simd_loop_meta": { "output_inplace": false, "array_pad": 0, "scratch": [], "axes_order": [ "n" ] } }