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Changing -O to opt-level=3 #828
Description
Proposal
The -O flag has existed for over 14 years, predating opt-levels entirely. It is somewhat surprising that it means opt-level=2, especially as Cargo's release profile uses level 3.
In C compilers, (Not sure this part is true)-O usually means a non-maximum opt level as some optimizations can cause unsoundness; Rust doesn't have this limitation.
I'd like to propose changing this shorthand flag to a more useful default.
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 mergeon either the MCP or the PR.
- Finding a "second" suffices for internal changes. If however, you are proposing a new public-facing feature, such as a
- 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.
Activity
rustbot commentedon Jan 14, 2025
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.
Concerns or objections to the proposal should be discussed on Zulip and formally registered here by adding a comment with the following syntax:
Concerns can be lifted with:
See documentation at https://forge.rust-lang.org
cc @rust-lang/compiler
Noratrieb commentedon Jan 14, 2025
@rustbot second
apiraino commentedon Jan 27, 2025
@rustbot label -final-comment-period +major-change-accepted
Rollup merge of rust-lang#135439 - clubby789:O3, r=Noratrieb
Rollup merge of rust-lang#135439 - clubby789:O3, r=Noratrieb
Rollup merge of rust-lang#135439 - clubby789:O3, r=Noratrieb
Rollup merge of rust-lang#135439 - clubby789:O3, r=Noratrieb
Unrolled build for rust-lang#135439
Rollup merge of #135439 - clubby789:O3, r=Noratrieb
Rollup merge of #135439 - clubby789:O3, r=Noratrieb