# megengine.functional.left_shift¶

left_shift(x, y)[源代码]

Element-wise left shift.

Shifts the bits of each element $$x_i$$ of the input tensor $$x$$ to the left by appending $$y_i$$ (i.e., the respective element in the input tesnor $$y$$) zeros to the right of $$x_i$$.

The << operator can be used as a shorthand for left_shift on Tensors.

• x – first input tensor. Should have an integer data type.

• y – second input tensor. Must be compatible with $$x$$ (see 广播机制与规则 ). Should have an integer data type. Each element must be greater than or equal to 0.

a tensor containing the result of the element-wise left shift operation. The returned tensor must have the a data type determined by 类型提升规则.

>>> F.left_shift([1, 2, 3], 1)
Tensor([2 4 6], dtype=int32, device=xpux:0)


Element-wise left shift:

>>> x = Tensor([1, 2, 3])
>>> y = Tensor([1, 2, 3])
>>> F.left_shift(x, y)
Tensor([ 2  8 24], dtype=int32, device=xpux:0)


>>> F.left_shift(5, [1, 2, 3])