Merge pull request #24 from LaurentMazare/more-grads

Support gradients for reshape and where_cond.
This commit is contained in:
Laurent Mazare
2023-06-28 10:04:51 +01:00
committed by GitHub
2 changed files with 17 additions and 6 deletions

View File

@ -106,9 +106,8 @@ impl Tensor {
}
let grad = grads.remove(node).unwrap();
// TODO: We should perform all these operations in place (or at least not track the
// whole graph).
// The only drawback would be if we wanted to support grad of grad but this is out of
// scope.
// whole graph). The only drawback would be if we wanted to support grad of grad but
// this is out of scope.
if let Some(op) = node.op() {
match op {
Op::Add(lhs, rhs) => {
@ -139,8 +138,14 @@ impl Tensor {
let rhs_sum_grad = grads.or_insert(rhs)?;
*rhs_sum_grad = rhs_sum_grad.add(&rhs_grad)?;
}
Op::WhereCond(_pred, _t, _f) => {
return Err(Error::BackwardNotSupported { op: "where_cond" })
Op::WhereCond(pred, t, f) => {
let zeros = grad.zeros_like()?;
let t_sum_grad = grads.or_insert(t)?;
let t_grad = pred.where_cond(&grad, &zeros)?;
*t_sum_grad = t_sum_grad.add(&t_grad)?;
let f_sum_grad = grads.or_insert(f)?;
let f_grad = pred.where_cond(&zeros, &grad)?;
*f_sum_grad = f_sum_grad.add(&f_grad)?;
}
Op::Embedding(_lhs, _rhs) => {
return Err(Error::BackwardNotSupported { op: "embedding" })
@ -209,7 +214,11 @@ impl Tensor {
Op::Softmax(_arg, _) => {
return Err(Error::BackwardNotSupported { op: "softmax" })
}
Op::Reshape(_arg) => return Err(Error::BackwardNotSupported { op: "reshape" }),
Op::Reshape(arg) => {
let arg_grad = grad.reshape(arg.dims())?;
let sum_grad = grads.or_insert(arg)?;
*sum_grad = sum_grad.add(&arg_grad)?
}
Op::Gelu(_) => return Err(Error::BackwardNotSupported { op: "gelu" }),
Op::Relu(_) => return Err(Error::BackwardNotSupported { op: "relu" }),
Op::Sqr(arg) => {

View File

@ -121,6 +121,7 @@ fn from_storage<S: Into<Shape>>(
}
impl Tensor {
// TODO: Maybe this should be a broadcast rather than actually creating the full tensor.
fn ones_impl<S: Into<Shape>>(
shape: S,
dtype: DType,
@ -144,6 +145,7 @@ impl Tensor {
Tensor::ones(self.shape(), self.dtype(), &self.device())
}
// TODO: Maybe this should be a broadcast rather than actually creating the full tensor.
fn zeros_impl<S: Into<Shape>>(
shape: S,
dtype: DType,