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wrapping shift: remove first bitmask and table #143355

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@hkBst hkBst commented Jul 3, 2025 •
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        #[inline(always)]
        pub const fn wrapping_shl(self, rhs: u32) -> Self {
            // SAFETY: the masking by the bitsize of the type ensures that we do not shift
            // out of bounds
            unsafe {
                self.unchecked_shl(rhs & (Self::BITS - 1))
            }
        }

already does the bitmask, so it seems unnecessary here.

More context: internals.rust-lang.org/t/wrapping-shift-operator-code-doing-bitmasking-twice/23167

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rustbot commented Jul 3, 2025

r? @Mark-Simulacrum

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@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Jul 3, 2025
@rust-cloud-vms rust-cloud-vms bot force-pushed the cleanup-shift-double-bitmask branch from f2896cf to f1b5a56 Compare July 3, 2025 09:05
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cc #30733 (also linked in internals, but linking here too)

@bors r+

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bors commented Jul 13, 2025

📌 Commit f1b5a56 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 Jul 13, 2025
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this pull request Jul 13, 2025
@matthiaskrgr
Rollup merge of rust-lang#143355 - hkBst:cleanup-shift-double-bitmask…
1add015 
…, r=Mark-Simulacrum

wrapping shift: remove first bitmask and table

```rust
        #[inline(always)]
        pub const fn wrapping_shl(self, rhs: u32) -> Self {
            // SAFETY: the masking by the bitsize of the type ensures that we do not shift
            // out of bounds
            unsafe {
                self.unchecked_shl(rhs & (Self::BITS - 1))
            }
        }
```
already does the bitmask, so it seems unnecessary here.

More context: internals.rust-lang.org/t/wrapping-shift-operator-code-doing-bitmasking-twice/23167
@matthiaskrgr matthiaskrgr mentioned this pull request Jul 13, 2025
Closed
bors added a commit that referenced this pull request Jul 13, 2025
@bors
Auto merge of #143899 - matthiaskrgr:rollup-6y7eeo5, r=matthiaskrgr
fc2e8e6 
Rollup of 8 pull requests

Successful merges:

 - #142885 (core: Add `BorrowedCursor::with_unfilled_buf`)
 - #143217 (Port #[link_ordinal] to the new attribute parsing infrastructure)
 - #143355 (wrapping shift: remove first bitmask and table)
 - #143448 (remote-test-client: Exit code `128 + <signal-number>` instead of `3`)
 - #143724 (Tidy cleanup)
 - #143820 (Fixed a core crate compilation failure when enabling the `optimize_for_size` feature on some targets)
 - #143850 (Compiletest: Simplify {Html,Json}DocCk directive handling)
 - #143880 (tests: Test line debuginfo for linebreaked function parameters)

Failed merges:

 - #143630 (Drop `./x suggest`)
 - #143733 (Change bootstrap's `tool.TOOL_NAME.features` to work on any subcommand)

r? `@ghost`
`@rustbot` modify labels: rollup
fmease added a commit to fmease/rust that referenced this pull request Jul 14, 2025
@fmease
Rollup merge of rust-lang#143355 - hkBst:cleanup-shift-double-bitmask…
0f93385 
…, r=Mark-Simulacrum

wrapping shift: remove first bitmask and table

```rust
        #[inline(always)]
        pub const fn wrapping_shl(self, rhs: u32) -> Self {
            // SAFETY: the masking by the bitsize of the type ensures that we do not shift
            // out of bounds
            unsafe {
                self.unchecked_shl(rhs & (Self::BITS - 1))
            }
        }
```
already does the bitmask, so it seems unnecessary here.

More context: internals.rust-lang.org/t/wrapping-shift-operator-code-doing-bitmasking-twice/23167
@fmease fmease mentioned this pull request Jul 14, 2025
Closed
bors added a commit that referenced this pull request Jul 14, 2025
@bors
Auto merge of #143912 - fmease:rollup-vlt5sn8, r=fmease
4f0c949 
Rollup of 16 pull requests

Successful merges:

 - #142885 (core: Add `BorrowedCursor::with_unfilled_buf`)
 - #143217 (Port #[link_ordinal] to the new attribute parsing infrastructure)
 - #143355 (wrapping shift: remove first bitmask and table)
 - #143448 (remote-test-client: Exit code `128 + <signal-number>` instead of `3`)
 - #143592 (UWP: link ntdll functions using raw-dylib)
 - #143681 (bootstrap/miri: avoid rebuilds for test builds)
 - #143710 (Updates to random number generation APIs)
 - #143724 (Tidy cleanup)
 - #143820 (Fixed a core crate compilation failure when enabling the `optimize_for_size` feature on some targets)
 - #143850 (Compiletest: Simplify {Html,Json}DocCk directive handling)
 - #143855 (Port `#[omit_gdb_pretty_printer_section]` to the new attribute parsing)
 - #143868 (warn on align on fields to avoid breaking changes)
 - #143875 (update issue number for `const_trait_impl`)
 - #143881 (Use zero for initialized Once state)
 - #143887 (Run bootstrap tests sooner in the `x test` pipeline)
 - #143893 (Don't require `eh_personality` lang item on targets that have a personality)

Failed merges:

 - #143878 (Port `#[pointee]` to the new attribute parsing infrastructure)
 - #143891 (Port `#[coverage]` to the new attribute system)

r? `@ghost`
`@rustbot` modify labels: rollup
jhpratt added a commit to jhpratt/rust that referenced this pull request Jul 14, 2025
@jhpratt
Rollup merge of rust-lang#143355 - hkBst:cleanup-shift-double-bitmask…
fffc52e 
…, r=Mark-Simulacrum

wrapping shift: remove first bitmask and table

```rust
        #[inline(always)]
        pub const fn wrapping_shl(self, rhs: u32) -> Self {
            // SAFETY: the masking by the bitsize of the type ensures that we do not shift
            // out of bounds
            unsafe {
                self.unchecked_shl(rhs & (Self::BITS - 1))
            }
        }
```
already does the bitmask, so it seems unnecessary here.

More context: internals.rust-lang.org/t/wrapping-shift-operator-code-doing-bitmasking-twice/23167
@jhpratt jhpratt mentioned this pull request Jul 14, 2025
Closed
bors added a commit that referenced this pull request Jul 14, 2025
@bors
Auto merge of #143916 - jhpratt:rollup-oykjepf, r=jhpratt
c722941 
Rollup of 17 pull requests

Successful merges:

 - #142885 (core: Add `BorrowedCursor::with_unfilled_buf`)
 - #143217 (Port #[link_ordinal] to the new attribute parsing infrastructure)
 - #143355 (wrapping shift: remove first bitmask and table)
 - #143448 (remote-test-client: Exit code `128 + <signal-number>` instead of `3`)
 - #143681 (bootstrap/miri: avoid rebuilds for test builds)
 - #143710 (Updates to random number generation APIs)
 - #143724 (Tidy cleanup)
 - #143738 (Move several float tests to floats/mod.rs)
 - #143820 (Fixed a core crate compilation failure when enabling the `optimize_for_size` feature on some targets)
 - #143850 (Compiletest: Simplify {Html,Json}DocCk directive handling)
 - #143855 (Port `#[omit_gdb_pretty_printer_section]` to the new attribute parsing)
 - #143868 (warn on align on fields to avoid breaking changes)
 - #143875 (update issue number for `const_trait_impl`)
 - #143881 (Use zero for initialized Once state)
 - #143887 (Run bootstrap tests sooner in the `x test` pipeline)
 - #143893 (Don't require `eh_personality` lang item on targets that have a personality)
 - #143901 (Region constraint nits)

Failed merges:

 - #143878 (Port `#[pointee]` to the new attribute parsing infrastructure)
 - #143891 (Port `#[coverage]` to the new attribute system)

r? `@ghost`
`@rustbot` modify labels: rollup
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