NRVO: Allow occurrences of the return place in var debug info #76306
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The non-use occurrence of the return place in var debug info does not
currently inhibit NRVO optimization, but it will fail assertion in
`visit_place` when optimization is performed.
Relax assertion check to allow the return place in var debug info.
This case might be impossible to hit in optimization pipelines as of
now, but can be encountered in customized mir-opt-level=2 pipeline with
copy propagation disabled. For example in:
```
pub fn b(s: String) -> String {
a(s)
}
#[inline]
pub fn a(s: String) -> String {
let x = s;
let y = x;
y
}
```
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Sorry. I seem to have missed this one. This will cause any |
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Mapping different user variables to the same place is perfectly fine and makes user variables accessible from a debugger, so that option is definitely preferable. |
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@bors r+ |
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📌 Commit 0151061 has been approved by |
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Sep 12, 2020
…morse
NRVO: Allow occurrences of the return place in var debug info
The non-use occurrence of the return place in var debug info does not
currently inhibit NRVO optimization, but it will fail assertion in
`visit_place` when optimization is performed.
Relax assertion check to allow the return place in var debug info.
This case might be impossible to hit in optimization pipelines as of
now, but can be encountered in customized mir-opt-level=2 pipeline with
copy propagation disabled. For example in:
```rust
pub fn b(s: String) -> String {
a(s)
}
#[inline]
pub fn a(s: String) -> String {
let x = s;
let y = x;
y
}
```
|
☀️ Test successful - checks-actions, checks-azure |
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The non-use occurrence of the return place in var debug info does not
currently inhibit NRVO optimization, but it will fail assertion in
visit_placewhen optimization is performed.Relax assertion check to allow the return place in var debug info.
This case might be impossible to hit in optimization pipelines as of
now, but can be encountered in customized mir-opt-level=2 pipeline with
copy propagation disabled. For example in: