tqchen commented on a change in pull request #9533:
URL: https://github.com/apache/tvm/pull/9533#discussion_r752626980
##########
File path: src/relay/ir/expr.cc
##########
@@ -71,6 +71,29 @@ Tuple::Tuple(tvm::Array<relay::Expr> fields, Span span) {
data_ = std::move(n);
}
+Tuple Tuple::WithFields(Optional<Array<Expr>> opt_fields, Optional<Span>
opt_span) {
+ Array<Expr> fields = opt_fields.value_or(get()->fields);
Review comment:
I see, thanks for the explaination, if it is a mution semantics, then we
might want to rename it as SetXYZ(or COWSet?), like `Array.Set`.
It might be worth thinking a bit about the tradeoff since the original
semantics on the python and c++ side is WithAttrs do not mutate the original
value that is passed in(unless it is moved in and ensures that there is no
followup), the api name With is also deliberately chosen over SetXYZ to show
that intention(that we do not modify the original value). So it would be good
to make it align with the WithAttrs semantics.
Since a common usage pattern may ends up look like this:
```python
x = PrimFunc(args, body)
# y is a new copy that comes with a new attr
# x remains as the original case
y = x.with_attr("new_attr", value)
record([x, y])
```
So in the c++ API
```c++
// y do not reuse x' sapce
y = WithAttrs(x, attr)
record({y, x})
```
Instead if you do
```c++
// compiler could decide that y can reuse x, because x is no longer used,
the call becomes a move
y = WithAttrs(x, attr)
// x is not used as a followup work
```
And with a deliberate move where x is the only copy, we ensures that x's
space get reused
```c++
y = WithAttrs(std::move(x), attr)
// x is not used as a followup work
```
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
