compiler: Don't mark SingleUseConsts MIR pass as "required for soundness"#152729
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Enselic wants to merge 1 commit intorust-lang:mainfrom
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compiler: Don't mark SingleUseConsts MIR pass as "required for soundness"#152729Enselic wants to merge 1 commit intorust-lang:mainfrom
SingleUseConsts MIR pass as "required for soundness"#152729Enselic wants to merge 1 commit intorust-lang:mainfrom
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Some changes occurred to MIR optimizations cc @rust-lang/wg-mir-opt |
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rustbot has assigned @dingxiangfei2009. Use Why was this reviewer chosen?The reviewer was selected based on:
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…dness" Because: * Something like it did not exist before PR 107404 * That it is not run our mir-opt-level 0 indicates that it is not required for soundness * Its `MirPass::can_be_overridden()` is unchanged and thus returns true, indicating that it is not a required MIR pass. * No test fails in PR 151426 that stops enabling by default in non-optimized builds As can be seen from the updated test `tests/mir-opt/optimize_none.rs`, this means that `#[optimize(none)]` functions become even less optimized. As expected and as desired.
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@bors r+ |
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I don't think this MIR pass is required for soundness. The reasons are:
SingleUseConsts(see AddSingleUseConstsmir-opt pass #125910 for the switch).#[optimize(none)]#128657 (comment) we can conclude it is not required for soundness since it has only ever run on MIR opt level > 0.MirPass::can_be_overridden()is unchanged and thus returnstrue, indicating that it is not a required MIR pass.mir_opt_level > 1forSingleUseConstsMIR pass #151426 which stops enabling it by default in non-optimized builds.As shown in the updated test
tests/mir-opt/optimize_none.rs,#[optimize(none)]functions become even less optimized, as expected and desired.Unblocks #151426.