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De-llvm some integer intrinsics that on the Rust side always use u32 #693

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WaffleLapkin opened this issue Nov 26, 2023 · 3 comments
Closed
1 of 3 tasks

De-llvm some integer intrinsics that on the Rust side always use u32 #693

WaffleLapkin opened this issue Nov 26, 2023 · 3 comments
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major-change A proposal to make a major change to rustc major-change-accepted A major change proposal that was accepted T-compiler Add this label so rfcbot knows to poll the compiler team

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@WaffleLapkin
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WaffleLapkin commented Nov 26, 2023 •
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Proposal

There is a number of integer operations which currently use an intrinsic which has T (type of the integer being operated on) in place where Rust methods use u32. All those methods have as u32s in the implementation.

The only reason why those signatures are the way they are, is because LLVM intrinsics expect them as such.

I propose to change the intrinsics to accept/return u32 and make LLVM backend insert necessary casts.

Here is the list of intrinsics I propose to change:

I would also like to change codegen methods when applicable (for example the shl/ashr, lshr).

Disclosure: at my {job} we are working on a new backend for rustc, those changes would make my work a little bit easier.

(still, I think this makes sense even without the context of my work)

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@scottmcm

Process

The main points of the Major Change Process are as follows:

  • File an issue describing the proposal.
  • A compiler team member or contributor who is knowledgeable in the area can second by writing @rustbot second.
    • Finding a "second" suffices for internal changes. If however, you are proposing a new public-facing feature, such as a -C flag, then full team check-off is required.
    • Compiler team members can initiate a check-off via @rfcbot fcp merge on either the MCP or the PR.
  • Once an MCP is seconded, the Final Comment Period begins. If no objections are raised after 10 days, the MCP is considered approved.

You can read more about Major Change Proposals on forge.

Comments

This issue is not meant to be used for technical discussion. There is a Zulip stream for that. Use this issue to leave procedural comments, such as volunteering to review, indicating that you second the proposal (or third, etc), or raising a concern that you would like to be addressed.
@WaffleLapkin WaffleLapkin added T-compiler Add this label so rfcbot knows to poll the compiler team major-change A proposal to make a major change to rustc labels Nov 26, 2023
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rustbot commented Nov 26, 2023

This issue is not meant to be used for technical discussion. There is a Zulip stream for that. Use this issue to leave procedural comments, such as volunteering to review, indicating that you second the proposal (or third, etc), or raising a concern that you would like to be addressed.

cc @rust-lang/compiler @rust-lang/compiler-contributors

@rustbot rustbot added the to-announce Announce this issue on triage meeting label Nov 26, 2023
@WaffleLapkin WaffleLapkin removed the to-announce Announce this issue on triage meeting label Nov 26, 2023
@davidtwco
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@rustbot second

@rustbot rustbot added the final-comment-period The FCP has started, most (if not all) team members are in agreement label Dec 7, 2023
@apiraino
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@rustbot label -final-comment-period +major-change-accepted

@rustbot rustbot added major-change-accepted A major change proposal that was accepted to-announce Announce this issue on triage meeting and removed final-comment-period The FCP has started, most (if not all) team members are in agreement labels Dec 18, 2023
@apiraino apiraino removed the to-announce Announce this issue on triage meeting label Dec 28, 2023
@scottmcm scottmcm mentioned this issue Mar 30, 2024
Merged
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this issue Apr 2, 2024
@matthiaskrgr
Rollup merge of rust-lang#123226 - scottmcm:u32-shifts, r=WaffleLapkin
e256d0b 
De-LLVM the unchecked shifts [MCP#693]

This is just one part of the MCP (rust-lang/compiler-team#693), but it's the one that IMHO removes the most noise from the standard library code.

Seems net simpler this way, since MIR already supported heterogeneous shifts anyway, and thus it's not more work for backends than before.

r? WaffleLapkin
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this issue Apr 2, 2024
@matthiaskrgr
Rollup merge of rust-lang#123226 - scottmcm:u32-shifts, r=WaffleLapkin
1b0e46f 
De-LLVM the unchecked shifts [MCP#693]

This is just one part of the MCP (rust-lang/compiler-team#693), but it's the one that IMHO removes the most noise from the standard library code.

Seems net simpler this way, since MIR already supported heterogeneous shifts anyway, and thus it's not more work for backends than before.

r? WaffleLapkin
rust-timer added a commit to rust-lang-ci/rust that referenced this issue Apr 2, 2024
@rust-timer
Unrolled build for rust-lang#123226
e50269b 
Rollup merge of rust-lang#123226 - scottmcm:u32-shifts, r=WaffleLapkin

De-LLVM the unchecked shifts [MCP#693]

This is just one part of the MCP (rust-lang/compiler-team#693), but it's the one that IMHO removes the most noise from the standard library code.

Seems net simpler this way, since MIR already supported heterogeneous shifts anyway, and thus it's not more work for backends than before.

r? WaffleLapkin
@WaffleLapkin WaffleLapkin mentioned this issue Apr 16, 2024
Merged
@scottmcm scottmcm mentioned this issue Apr 19, 2024
Merged
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this issue Apr 23, 2024
@matthiaskrgr
Rollup merge of rust-lang#124003 - WaffleLapkin:dellvmization, r=scot…
bbda9b6 
…tmcm,RalfJung,antoyo

Dellvmize some intrinsics (use `u32` instead of `Self` in some integer intrinsics)

This implements rust-lang/compiler-team#693 minus what was implemented in rust-lang#123226.

Note: I decided to _not_ change `shl`/... builder methods, as it just doesn't seem worth it.

r? `@scottmcm`
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this issue Apr 23, 2024
@matthiaskrgr
Rollup merge of rust-lang#124003 - WaffleLapkin:dellvmization, r=scot…
918304b 
…tmcm,RalfJung,antoyo

Dellvmize some intrinsics (use `u32` instead of `Self` in some integer intrinsics)

This implements rust-lang/compiler-team#693 minus what was implemented in rust-lang#123226.

Note: I decided to _not_ change `shl`/... builder methods, as it just doesn't seem worth it.

r? ``@scottmcm``
rust-timer added a commit to rust-lang-ci/rust that referenced this issue Apr 23, 2024
@rust-timer
Unrolled build for rust-lang#124003
d3dd073 
Rollup merge of rust-lang#124003 - WaffleLapkin:dellvmization, r=scottmcm,RalfJung,antoyo

Dellvmize some intrinsics (use `u32` instead of `Self` in some integer intrinsics)

This implements rust-lang/compiler-team#693 minus what was implemented in rust-lang#123226.

Note: I decided to _not_ change `shl`/... builder methods, as it just doesn't seem worth it.

r? ``@scottmcm``
github-actions bot pushed a commit to rust-lang/miri that referenced this issue Apr 24, 2024
@matthiaskrgr
Rollup merge of #124003 - WaffleLapkin:dellvmization, r=scottmcm,Ralf…
8afe33d 
…Jung,antoyo

Dellvmize some intrinsics (use `u32` instead of `Self` in some integer intrinsics)

This implements rust-lang/compiler-team#693 minus what was implemented in #123226.

Note: I decided to _not_ change `shl`/... builder methods, as it just doesn't seem worth it.

r? ``@scottmcm``
bjorn3 pushed a commit to rust-lang/rustc_codegen_cranelift that referenced this issue Apr 28, 2024
@matthiaskrgr
Rollup merge of #124003 - WaffleLapkin:dellvmization, r=scottmcm,Ralf…
6a2ad55 
…Jung,antoyo

Dellvmize some intrinsics (use `u32` instead of `Self` in some integer intrinsics)

This implements rust-lang/compiler-team#693 minus what was implemented in #123226.

Note: I decided to _not_ change `shl`/... builder methods, as it just doesn't seem worth it.

r? ``@scottmcm``
GuillaumeGomez pushed a commit to GuillaumeGomez/rustc_codegen_gcc that referenced this issue May 21, 2024
@matthiaskrgr
Rollup merge of #124003 - WaffleLapkin:dellvmization, r=scottmcm,Ralf…
79d217f 
…Jung,antoyo

Dellvmize some intrinsics (use `u32` instead of `Self` in some integer intrinsics)

This implements rust-lang/compiler-team#693 minus what was implemented in #123226.

Note: I decided to _not_ change `shl`/... builder methods, as it just doesn't seem worth it.

r? ``@scottmcm``
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