Avoid copying the data on squeeze and unsqueeze. (#1884)

* Avoid copying the data on squeeze and unsqueeze.

* Fix the quantized llama example.

* Unrelated fix for the quantized stable-lm example on cuda.

* Fix for mamba on cuda (unrelated to the PR).
This commit is contained in:
Laurent Mazare
2024-03-20 13:04:36 +01:00
committed by GitHub
parent 2a8679509e
commit 455c42aa72
5 changed files with 47 additions and 8 deletions

View File

@ -2093,8 +2093,19 @@ impl Tensor {
let dim = dim.to_index(self.shape(), "squeeze")?;
if dims[dim] == 1 {
let mut dims = dims.to_vec();
let mut strides = self.stride().to_vec();
dims.remove(dim);
self.reshape(dims)
strides.remove(dim);
let tensor_ = Tensor_ {
id: TensorId::new(),
storage: self.storage.clone(),
layout: Layout::new(dims.into(), strides, self.layout.start_offset()),
op: BackpropOp::new1(self, Op::Reshape),
is_variable: false,
dtype: self.dtype,
device: self.device.clone(),
};
Ok(Tensor(Arc::new(tensor_)))
} else {
Ok(self.clone())
}
@ -2115,10 +2126,24 @@ impl Tensor {
/// ```
pub fn unsqueeze<D: Dim>(&self, dim: D) -> Result<Self> {
let mut dims = self.dims().to_vec();
let mut strides = self.stride().to_vec();
let dim = dim.to_index_plus_one(self.shape(), "unsqueeze")?;
// Cannot panic because to_index_plus_one already checks dimensions
dims.insert(dim, 1);
self.reshape(dims)
// Any stride would work here, but we pick one so as to maximize the probability to remain
// C contiguous.
let stride = if dim < strides.len() { strides[dim] } else { 1 };
strides.insert(dim, stride);
let tensor_ = Tensor_ {
id: TensorId::new(),
storage: self.storage.clone(),
layout: Layout::new(dims.into(), strides, self.layout.start_offset()),
op: BackpropOp::new1(self, Op::Reshape),
is_variable: false,
dtype: self.dtype,
device: self.device.clone(),
};
Ok(Tensor(Arc::new(tensor_)))
}
/// Stacks two or more tensors along a particular dimension.