ttnn.logical_left_shift

ttnn.logical_left_shift(input_tensor_a: ttnn.Tensor, input_tensor_b: ttnn.Tensor or Integer, *, memory_config: ttnn.MemoryConfig = None, output_tensor: ttnn.Tensor = None, sub_core_grids: ttnn.CoreRangeSet = None, sub_device_id: ttnn.SubDeviceId = None) → ttnn.Tensor

Perform logical_left_shift operation on input_tensor_a by input_tensor_b and returns the tensor with the same layout as input_tensor_a. input_tensor_b has shift_bits which are integers within range (0, 31). Equivalent to multiplying by 2^shift_amt.

\[\mathrm{{output\_tensor}}_i = \verb|logical_left_shift|(\mathrm{{input\_tensor\_a, input\_tensor\_b}})\]
Parameters:

  • input_tensor_a (ttnn.Tensor)the input tensor.

  • input_tensor_b (ttnn.Tensor or Integer)the input tensor.

Keyword Arguments:

  • memory_config (ttnn.MemoryConfig, optional)memory configuration for the operation. Defaults to None.

  • output_tensor (ttnn.Tensor, optional)preallocated output tensor. Defaults to None.

  • sub_core_grids (ttnn.CoreRangeSet, optional)restrict execution to a subset of cores (e.g. for subdevice use). Defaults to None.

  • sub_device_id (ttnn.SubDeviceId, optional)sub device ID — the op resolves cores internally. Mutually exclusive with sub_core_grids. Defaults to None.

Returns:

ttnn.Tensorthe output tensor.

Binary elementwise operations, C=op(A,B), support input tensors A and B in tile and row major layouts (unless dtype requires specific layout, e.g. BFLOAT8_B or BFLOAT4_B), in interleaved or sharded format (height, width or block sharded), in DRAM or L1. A and B are independent, and can have different tensor specs, with restrictions as in notes below.

Broadcast of A and B operands is supported up to dimension 5 (DNCHW). Any dimensions of size 1 in either A or B will be expanded to match the other input, and data will be duplicated along that dimension. For example, if the shape of A is [2,1,1,32] and B is [1,16,8,1], the output shape will be [2,16,8,32]. The size of dimensions higher than 5 must match between A and B.

The output C supports the same layouts and formats as A and B, under the same dtype restriction. For operations that return a new tensor, the layout and memory configuration of C are independent of A and B. The memory configuration can be set with memory_config, and the full tensor spec with output_tensor where the operation takes one; if neither is given, the operation will attempt a best decision at an appropriate tensor spec. The dimensions of C, or of output_tensor if given, must match the broadcast-matched size of A and B. By default, C takes the dtype of A unless an operation-specific rule applies: comparison ops return a boolean mask, and a mixed float pair follows A rather than the wider dtype. There is no boolean dtype, so the mask is carried as 1 for true and 0 for false in the output dtype. Where supported, the output dtype can be overridden by the dtype argument or output_tensor. In-place operations write into A, so C is A and keeps its layout, memory configuration and dtype.

Performance considerations: Elementwise operations operate natively in tile format, tiled tensors are preferred as an input, and row-major tensors are tilized and untilized during the operation. L1 sharded layout is preferred, with no broadcast and matching tensor specs for A, B and C.

Note

Supported dtypes and layouts:

Dtypes

Layouts

INT32, UINT16 (range: [0, 65535]), UINT32 (range: [0, 4294967295])

TILE, ROW_MAJOR

If the input tensor is ROW_MAJOR layout, it will be internally converted to TILE layout.

Operands must have the same dtype.

Example

# Create a tensor with specific integer values
tensor = ttnn.from_torch(torch.tensor([[1, 2], [4, 8]], dtype=torch.int32), layout=ttnn.TILE_LAYOUT, device=device)

# Perform logical left shift by 2 bits
output = ttnn.logical_left_shift(tensor, 2)
logger.info(f"Logical left shift: {output}")