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Add LLVM15-specific codegen test for try/?s that now optimize away #100693

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merged 1 commit into from
Aug 20, 2022
Merged

Add LLVM15-specific codegen test for try/?s that now optimize away #100693

merged 1 commit into from
Aug 20, 2022

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scottmcm
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These still generated a bunch of code back in Rust 1.63 (https://rust.godbolt.org/z/z31P8h6rz), but with LLVM 15 merged they no longer do 🎉

@scottmcm
Add LLVM15-specific codegen test for try/?s that now optimize away
5145c97 
These still generated a bunch of code back in Rust 1.63 (<https://rust.godbolt.org/z/z31P8h6rz>), but with LLVM 15 merged they no longer do 🎉
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r? @Mark-Simulacrum

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@rust-highfive rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Aug 17, 2022
This was referenced Aug 17, 2022
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@bors rollup=iffy (codegen test that doesn't run in the PR build, because that uses LLVM 13 but the test needs LLVM 15)

Kobzol
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Could you also include a test with Ok(x?)? I think that this pattern is also quite common.

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scottmcm commented Aug 17, 2022 •
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Could you also include a test with Ok(x?)?

Because MIR inlining is on now, that's very much the same as the try { x? } one now -- you can look at the MIR in https://play.rust-lang.org/?version=nightly&mode=release&edition=2021&gist=80afa100459d91316f209cfb2d8100d8 and see the "inlined <Result<i32, u32> as Try>::from_output" and that function is just Ok:

rust/library/core/src/result.rs

Lines 2111 to 2114 in 9c20b2a

#[inline]
fn from_output(output: Self::Output) -> Self {
Ok(output)
}

Basically what I picked here is the direct one -- the obvious match -- and the indirect one -- that to NOP has to see through all the trait calls -- so if the most-indirect one is fine, I'm not sure it's worth also listing the spots in the middle.

@scottmcm scottmcm mentioned this pull request Aug 19, 2022
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@bors r+ rollup=iffy

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bors commented Aug 20, 2022

📌 Commit 5145c97 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Aug 20, 2022
@matthiaskrgr matthiaskrgr mentioned this pull request Aug 20, 2022
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bors added a commit to rust-lang-ci/rust that referenced this pull request Aug 20, 2022
@bors
Auto merge of rust-lang#100809 - matthiaskrgr:rollup-xkpd5ii, r=matth…
48853a3 
…iaskrgr

Rollup of 9 pull requests

Successful merges:

 - rust-lang#99415 (Initial implementation of REUSE)
 - rust-lang#99544 (Expose `Utf8Lossy` as `Utf8Chunks`)
 - rust-lang#100585 (Fix trailing space showing up in example)
 - rust-lang#100596 (Remove unnecessary stderr files)
 - rust-lang#100642 (Update fortanix-sgx-abi and export some useful SGX usercall traits)
 - rust-lang#100691 (Make `same_type_modulo_infer` a proper `TypeRelation`)
 - rust-lang#100693 (Add LLVM15-specific codegen test for `try`/`?`s that now optimize away)
 - rust-lang#100710 (Windows: Load synch functions together)
 - rust-lang#100807 (Add TaKO8Ki to translation-related mention groups)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
@bors bors merged commit 45568bd into rust-lang:master Aug 20, 2022
@rustbot rustbot added this to the 1.65.0 milestone Aug 20, 2022
@scottmcm scottmcm deleted the new-llvm15-nops branch August 20, 2022 20:10
@nikic nikic mentioned this pull request Aug 30, 2022
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bors added a commit to rust-lang-ci/rust that referenced this pull request Sep 6, 2022
@bors
Auto merge of rust-lang#100733 - scottmcm:inline-from-from-identity, …
380addd 
…r=m-ou-se

Inline `<T as From<T>>::from`

I noticed (in rust-lang#100693 (comment)) that the MIR for <https://play.rust-lang.org/?version=nightly&mode=release&edition=2021&gist=67097e0494363ee27421a4e3bdfaf513> has inlined most stuff
```
scope 5 (inlined <Result<i32, u32> as Try>::branch)
```
```
scope 8 (inlined <Result<i32, u32> as Try>::from_output)
```

But yet the do-nothing `from` call was still there:
```
_17 = <u32 as From<u32>>::from(move _18) -> bb9;
```

So let's give this a try and see what perf has to say.
workingjubilee pushed a commit to tcdi/postgrestd that referenced this pull request Sep 15, 2022
@bors
Auto merge of #100733 - scottmcm:inline-from-from-identity, r=m-ou-se
c12dc6b 
Inline `<T as From<T>>::from`

I noticed (in rust-lang/rust#100693 (comment)) that the MIR for <https://play.rust-lang.org/?version=nightly&mode=release&edition=2021&gist=67097e0494363ee27421a4e3bdfaf513> has inlined most stuff
```
scope 5 (inlined <Result<i32, u32> as Try>::branch)
```
```
scope 8 (inlined <Result<i32, u32> as Try>::from_output)
```

But yet the do-nothing `from` call was still there:
```
_17 = <u32 as From<u32>>::from(move _18) -> bb9;
```

So let's give this a try and see what perf has to say.
@Stebalien Stebalien mentioned this pull request Jan 2, 2023
Closed
RalfJung pushed a commit to RalfJung/rust-analyzer that referenced this pull request Apr 20, 2024
@bors
Auto merge of #100733 - scottmcm:inline-from-from-identity, r=m-ou-se
411f3c0 
Inline `<T as From<T>>::from`

I noticed (in rust-lang/rust#100693 (comment)) that the MIR for <https://play.rust-lang.org/?version=nightly&mode=release&edition=2021&gist=67097e0494363ee27421a4e3bdfaf513> has inlined most stuff
```
scope 5 (inlined <Result<i32, u32> as Try>::branch)
```
```
scope 8 (inlined <Result<i32, u32> as Try>::from_output)
```

But yet the do-nothing `from` call was still there:
```
_17 = <u32 as From<u32>>::from(move _18) -> bb9;
```

So let's give this a try and see what perf has to say.
RalfJung pushed a commit to RalfJung/rust-analyzer that referenced this pull request Apr 27, 2024
@bors
Auto merge of #100733 - scottmcm:inline-from-from-identity, r=m-ou-se
d6c0b7b 
Inline `<T as From<T>>::from`

I noticed (in rust-lang/rust#100693 (comment)) that the MIR for <https://play.rust-lang.org/?version=nightly&mode=release&edition=2021&gist=67097e0494363ee27421a4e3bdfaf513> has inlined most stuff
```
scope 5 (inlined <Result<i32, u32> as Try>::branch)
```
```
scope 8 (inlined <Result<i32, u32> as Try>::from_output)
```

But yet the do-nothing `from` call was still there:
```
_17 = <u32 as From<u32>>::from(move _18) -> bb9;
```

So let's give this a try and see what perf has to say.
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