rust/src/test/mir-opt/simplify_try_if_let/rustc.{{impl}}-append.SimplifyArmIdentity.diff, branch 1.45.0https://github.com/rust-lang/rust
http://git.dreamy.place/mirrors/rust/atom?h=1.45.02020-06-26T13:34:18+00:00Disable the `SimplifyArmIdentity` pass on beta2020-06-26T13:34:18+00:00Wesley Wiserwwiser@gmail.com2020-06-12T00:46:55+00:00urn:sha1:483608a4d2de8a828e7292f4d3686acbd030e0e7
This pass is buggy so I'm disabling it to fix a stable-to-beta
regression.
Related to #73223
Modify SimplifyArmIdentity so it can trigger on mir-opt-level=12020-05-12T00:31:02+00:00Wesley Wiserwwiser@gmail.com2020-05-12T00:13:15+00:00urn:sha1:6de6d70ae0a21b779d63d885438c7214e17e7a6d
I also added test cases to make sure the optimization can fire on all of
these cases:
```rust
fn case_1(o: Option<u8>) -> Option<u8> {
match o {
Some(u) => Some(u),
None => None,
}
}
fn case2(r: Result<u8, i32>) -> Result<u8, i32> {
match r {
Ok(u) => Ok(u),
Err(i) => Err(i),
}
}
fn case3(r: Result<u8, i32>) -> Result<u8, i32> {
let u = r?;
Ok(u)
}
```
Without MIR inlining, this still does not completely optimize away the
`?` operator because the `Try::into_result()`, `From::from()` and
`Try::from_error()` calls still exist. This does move us a bit closer to
that goal though because:
- We can now run the pass on mir-opt-level=1
- We no longer depend on the copy propagation pass running which is
unlikely to stabilize anytime soon.