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Rollup of 15 pull requests #52958

Merged
merged 32 commits into from
Aug 1, 2018
Merged

Rollup of 15 pull requests #52958

merged 32 commits into from
Aug 1, 2018

Commits on Jul 28, 2018

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Commits on Jul 30, 2018

  1. fix memrchr in miri

    RalfJung committed Jul 30, 2018
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Commits on Jul 31, 2018

  1. tests/ui: Add missing mips{64} ignores

    dragan.mladjenovic committed Jul 31, 2018
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  2. Use SetLenOnDrop in Vec::truncate()

    This avoids a redundant length check in some cases when calling
    `Vec::truncate` or `Vec::clear`.
    
    Fixes rust-lang#51802
    lnicola committed Jul 31, 2018
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  5. Don't count MIR locals as borrowed after StorageDead when finding loc…

    …als live across a yield terminator
    Zoxc committed Jul 31, 2018
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Commits on Aug 1, 2018

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  2. Another SmallVec.extend optimization

    This improves SmallVec.extend even more over rust-lang#52859
    
    Before (as of rust-lang#52859):
    
    ```
    test small_vec::tests::fill_small_vec_1_10_with_cap  ... bench:          31 ns/iter (+/- 5)
    test small_vec::tests::fill_small_vec_1_10_wo_cap    ... bench:          70 ns/iter (+/- 4)
    test small_vec::tests::fill_small_vec_1_50_with_cap  ... bench:          36 ns/iter (+/- 3)
    test small_vec::tests::fill_small_vec_1_50_wo_cap    ... bench:         256 ns/iter (+/- 17)
    test small_vec::tests::fill_small_vec_32_10_with_cap ... bench:          31 ns/iter (+/- 5)
    test small_vec::tests::fill_small_vec_32_10_wo_cap   ... bench:          26 ns/iter (+/- 1)
    test small_vec::tests::fill_small_vec_32_50_with_cap ... bench:          49 ns/iter (+/- 4)
    test small_vec::tests::fill_small_vec_32_50_wo_cap   ... bench:         219 ns/iter (+/- 11)
    test small_vec::tests::fill_small_vec_8_10_with_cap  ... bench:          32 ns/iter (+/- 2)
    test small_vec::tests::fill_small_vec_8_10_wo_cap    ... bench:          61 ns/iter (+/- 12)
    test small_vec::tests::fill_small_vec_8_50_with_cap  ... bench:          37 ns/iter (+/- 3)
    test small_vec::tests::fill_small_vec_8_50_wo_cap    ... bench:         210 ns/iter (+/- 10)
    ```
    
    After:
    
    ```
    test small_vec::tests::fill_small_vec_1_10_wo_cap    ... bench:          31 ns/iter (+/- 3)
    test small_vec::tests::fill_small_vec_1_50_with_cap  ... bench:          39 ns/iter (+/- 4)
    test small_vec::tests::fill_small_vec_1_50_wo_cap    ... bench:          35 ns/iter (+/- 4)
    test small_vec::tests::fill_small_vec_32_10_with_cap ... bench:          37 ns/iter (+/- 3)
    test small_vec::tests::fill_small_vec_32_10_wo_cap   ... bench:          32 ns/iter (+/- 2)
    test small_vec::tests::fill_small_vec_32_50_with_cap ... bench:          52 ns/iter (+/- 4)
    test small_vec::tests::fill_small_vec_32_50_wo_cap   ... bench:          46 ns/iter (+/- 0)
    test small_vec::tests::fill_small_vec_8_10_with_cap  ... bench:          35 ns/iter (+/- 4)
    test small_vec::tests::fill_small_vec_8_10_wo_cap    ... bench:          31 ns/iter (+/- 0)
    test small_vec::tests::fill_small_vec_8_50_with_cap  ... bench:          40 ns/iter (+/- 15)
    test small_vec::tests::fill_small_vec_8_50_wo_cap    ... bench:          36 ns/iter (+/- 2)
    ```
    llogiq committed Aug 1, 2018
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  6. rustc: Trim down the rust_2018_idioms lint group

    These migration lints aren't all up to par in terms of a good migration
    experience. Some, like `unreachable_pub`, hit bugs like rust-lang#52665 and unprepared
    macros to be handled enough of the time. Others like linting against
    `#[macro_use]` are swimming upstream in an ecosystem that's not quite ready (and
    slightly buggy pending a few current PRs).
    
    The general idea is that we will continue to recommend the `rust_2018_idioms`
    lint group as part of the transition guide (as an optional step) but we'll be
    much more selective about which lints make it into this group. Only those with a
    strong track record of not causing too much churn will make the cut.
    
    cc rust-lang#52679
    alexcrichton committed Aug 1, 2018
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  7. 1.27 actually added the armv5te-unknown-linux-musleabi target

    The PR title says `armv5te-unknown-linux-musl`, but it looks like the final code merge renamed the target to `armv5te-unknown-linux-musleabi`. `rustup` reports this as correct as well.
    
    The [Rust Platform Support](https://forge.rust-lang.org/platform-support.html) page needs this added as well, but I'm not certain what codebase that is generated from.
    Susurrus committed Aug 1, 2018
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  9. async can begin expressions

    cramertj committed Aug 1, 2018
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  10. Rollup merge of rust-lang#52793 - davidtwco:issue-49824, r=pnkfelix

    Add test for NLL: unexpected "free region `` does not outlive" error
    
    Fixes rust-lang#49824.
    
    r? @pnkfelix @nikomatsakis
    pietroalbini committed Aug 1, 2018
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  11. Rollup merge of rust-lang#52799 - Mark-Simulacrum:attr-id-bitvecs, r=…

    …michaelwoerister
    
    Use BitVector for global sets of AttrId
    pietroalbini committed Aug 1, 2018
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  12. Rollup merge of rust-lang#52809 - davidtwco:issue-49579, r=pnkfelix

    Add test for unexpected region for local data ReStatic
    
    Fixes rust-lang#49579.
    
    r? @pnkfelix @nikomatsakis
    pietroalbini committed Aug 1, 2018
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  13. Rollup merge of rust-lang#52834 - matthewjasper:allow-zst-conflicts, …

    …r=pnkfelix
    
    [NLL] Allow conflicting borrows of promoted length zero arrays
    
    This is currently overkill as there's no way to create two conflicting borrows of any promoted.
    It is possible that the following code might not fail due to const eval in the future (@oli-obk?). In which case either the array marked needs to not be promoted, or to be checked for conflicts
    
    ```rust
    static mut A: () = {
        let mut y = None;
        let z;
        let mut done_y = false;
        loop {
            let x = &mut [1];  // < this array
            if done_y {
                z = x;
                break;
            }
            y = Some(x);
            done_y = true;
        }
        some_const_fn(y, z); // some_const_fn expects that y to not alias z.
    };
    ```
    
    r? @pnkfelix  @nikomatsakis
    
    closes rust-lang#52671
    cc rust-lang#51823
    pietroalbini committed Aug 1, 2018
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  15. Rollup merge of rust-lang#52854 - RalfJung:memrchr, r=Kimundi

    fix memrchr in miri
    
    The previous PR rust-lang#52744 was not enough because it assumed that the split between the `mid` and `end` parts returned by `align_to` was aligned. But really the only guarantee we have is that the `mid` part is aligned, so make use of that.
    pietroalbini committed Aug 1, 2018
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  16. Rollup merge of rust-lang#52899 - draganmladjenovic:ui_tests64, r=ale…

    …xcrichton
    
    tests/ui: Add missing mips{64} ignores
    pietroalbini committed Aug 1, 2018
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  17. Rollup merge of rust-lang#52908 - lnicola:vec-truncate-opt, r=alexcri…

    …chton
    
    Use SetLenOnDrop in Vec::truncate()
    
    This avoids a redundant length check in some cases when calling
    `Vec::truncate` or `Vec::clear`.
    
    Fixes rust-lang#51802
    
    Note that the generated code still seems suboptimal. I tested with the following functions:
    
    ```rust
    #[no_mangle]
    pub extern fn foo(x: &mut Vec<u8>) {
        x.clear();
    }
    
    #[no_mangle]
    pub extern fn bar(x: &mut Vec<u8>) {
        x.truncate(5);
    }
    
    #[no_mangle]
    pub extern fn baz(x: &mut Vec<u8>, n: usize) {
        x.truncate(n);
    }
    
    #[no_mangle]
    pub extern fn foo_string(x: &mut Vec<String>) {
        x.clear();
    }
    
    #[no_mangle]
    pub extern fn bar_string(x: &mut Vec<String>) {
        x.truncate(5);
    }
    
    #[no_mangle]
    pub extern fn baz_string(x: &mut Vec<String>, n: usize) {
        x.truncate(n);
    }
    ```
    
    <details>
      <summary>Old output</summary>
    
    ```asm
    00000000000460a0 <foo>:
       460a0:       48 83 7f 10 00          cmpq   $0x0,0x10(%rdi)
       460a5:       74 08                   je     460af <foo+0xf>
       460a7:       48 c7 47 10 00 00 00    movq   $0x0,0x10(%rdi)
       460ae:       00
       460af:       c3                      retq
    
    00000000000460b0 <bar>:
       460b0:       48 83 7f 10 06          cmpq   $0x6,0x10(%rdi)
       460b5:       72 08                   jb     460bf <bar+0xf>
       460b7:       48 c7 47 10 05 00 00    movq   $0x5,0x10(%rdi)
       460be:       00
       460bf:       c3                      retq
    
    00000000000460c0 <baz>:
       460c0:       48 39 77 10             cmp    %rsi,0x10(%rdi)
       460c4:       76 04                   jbe    460ca <baz+0xa>
       460c6:       48 89 77 10             mov    %rsi,0x10(%rdi)
       460ca:       c3                      retq
       460cb:       0f 1f 44 00 00          nopl   0x0(%rax,%rax,1)
    
    00000000000460d0 <foo_string>:
       460d0:       41 57                   push   %r15
       460d2:       41 56                   push   %r14
       460d4:       53                      push   %rbx
       460d5:       48 8b 47 10             mov    0x10(%rdi),%rax
       460d9:       48 85 c0                test   %rax,%rax
       460dc:       74 4a                   je     46128 <foo_string+0x58>
       460de:       49 89 fe                mov    %rdi,%r14
       460e1:       48 8b 0f                mov    (%rdi),%rcx
       460e4:       48 8d 14 40             lea    (%rax,%rax,2),%rdx
       460e8:       48 8d 58 ff             lea    -0x1(%rax),%rbx
       460ec:       4c 8d 3c d1             lea    (%rcx,%rdx,8),%r15
       460f0:       49 83 c7 f0             add    $0xfffffffffffffff0,%r15
       460f4:       66 2e 0f 1f 84 00 00    nopw   %cs:0x0(%rax,%rax,1)
       460fb:       00 00 00
       460fe:       66 90                   xchg   %ax,%ax
       46100:       49 89 5e 10             mov    %rbx,0x10(%r14)
       46104:       49 8b 37                mov    (%r15),%rsi
       46107:       48 85 f6                test   %rsi,%rsi
       4610a:       74 0e                   je     4611a <foo_string+0x4a>
       4610c:       49 8b 7f f8             mov    -0x8(%r15),%rdi
       46110:       ba 01 00 00 00          mov    $0x1,%edx
       46115:       e8 a6 e9 ff ff          callq  44ac0 <__rust_dealloc@plt>
       4611a:       48 83 c3 ff             add    $0xffffffffffffffff,%rbx
       4611e:       49 83 c7 e8             add    $0xffffffffffffffe8,%r15
       46122:       48 83 fb ff             cmp    $0xffffffffffffffff,%rbx
       46126:       75 d8                   jne    46100 <foo_string+0x30>
       46128:       5b                      pop    %rbx
       46129:       41 5e                   pop    %r14
       4612b:       41 5f                   pop    %r15
       4612d:       c3                      retq
       4612e:       66 90                   xchg   %ax,%ax
    
    0000000000046130 <bar_string>:
       46130:       41 57                   push   %r15
       46132:       41 56                   push   %r14
       46134:       53                      push   %rbx
       46135:       4c 8b 7f 10             mov    0x10(%rdi),%r15
       46139:       49 83 ff 06             cmp    $0x6,%r15
       4613d:       72 49                   jb     46188 <bar_string+0x58>
       4613f:       49 89 fe                mov    %rdi,%r14
       46142:       48 8b 07                mov    (%rdi),%rax
       46145:       4b 8d 0c 7f             lea    (%r15,%r15,2),%rcx
       46149:       48 8d 1c c8             lea    (%rax,%rcx,8),%rbx
       4614d:       48 83 c3 f0             add    $0xfffffffffffffff0,%rbx
       46151:       66 2e 0f 1f 84 00 00    nopw   %cs:0x0(%rax,%rax,1)
       46158:       00 00 00
       4615b:       0f 1f 44 00 00          nopl   0x0(%rax,%rax,1)
       46160:       49 83 c7 ff             add    $0xffffffffffffffff,%r15
       46164:       4d 89 7e 10             mov    %r15,0x10(%r14)
       46168:       48 8b 33                mov    (%rbx),%rsi
       4616b:       48 85 f6                test   %rsi,%rsi
       4616e:       74 0e                   je     4617e <bar_string+0x4e>
       46170:       48 8b 7b f8             mov    -0x8(%rbx),%rdi
       46174:       ba 01 00 00 00          mov    $0x1,%edx
       46179:       e8 42 e9 ff ff          callq  44ac0 <__rust_dealloc@plt>
       4617e:       48 83 c3 e8             add    $0xffffffffffffffe8,%rbx
       46182:       49 83 ff 05             cmp    $0x5,%r15
       46186:       77 d8                   ja     46160 <bar_string+0x30>
       46188:       5b                      pop    %rbx
       46189:       41 5e                   pop    %r14
       4618b:       41 5f                   pop    %r15
       4618d:       c3                      retq
       4618e:       66 90                   xchg   %ax,%ax
    
    0000000000046190 <baz_string>:
       46190:       41 57                   push   %r15
       46192:       41 56                   push   %r14
       46194:       41 54                   push   %r12
       46196:       53                      push   %rbx
       46197:       50                      push   %rax
       46198:       4c 8b 67 10             mov    0x10(%rdi),%r12
       4619c:       49 39 f4                cmp    %rsi,%r12
       4619f:       76 46                   jbe    461e7 <baz_string+0x57>
       461a1:       49 89 f6                mov    %rsi,%r14
       461a4:       49 89 ff                mov    %rdi,%r15
       461a7:       48 8b 07                mov    (%rdi),%rax
       461aa:       4b 8d 0c 64             lea    (%r12,%r12,2),%rcx
       461ae:       48 8d 1c c8             lea    (%rax,%rcx,8),%rbx
       461b2:       48 83 c3 f0             add    $0xfffffffffffffff0,%rbx
       461b6:       66 2e 0f 1f 84 00 00    nopw   %cs:0x0(%rax,%rax,1)
       461bd:       00 00 00
       461c0:       49 83 c4 ff             add    $0xffffffffffffffff,%r12
       461c4:       4d 89 67 10             mov    %r12,0x10(%r15)
       461c8:       48 8b 33                mov    (%rbx),%rsi
       461cb:       48 85 f6                test   %rsi,%rsi
       461ce:       74 0e                   je     461de <baz_string+0x4e>
       461d0:       48 8b 7b f8             mov    -0x8(%rbx),%rdi
       461d4:       ba 01 00 00 00          mov    $0x1,%edx
       461d9:       e8 e2 e8 ff ff          callq  44ac0 <__rust_dealloc@plt>
       461de:       48 83 c3 e8             add    $0xffffffffffffffe8,%rbx
       461e2:       4d 39 f4                cmp    %r14,%r12
       461e5:       77 d9                   ja     461c0 <baz_string+0x30>
       461e7:       48 83 c4 08             add    $0x8,%rsp
       461eb:       5b                      pop    %rbx
       461ec:       41 5c                   pop    %r12
       461ee:       41 5e                   pop    %r14
       461f0:       41 5f                   pop    %r15
       461f2:       c3                      retq
       461f3:       90                      nop
       461f4:       66 2e 0f 1f 84 00 00    nopw   %cs:0x0(%rax,%rax,1)
       461fb:       00 00 00
       461fe:       66 90                   xchg   %ax,%ax
    ```
    </details>
    
    <details>
      <summary>New output</summary>
    
    ```asm
    0000000000084d10 <foo>:
       84d10:       48 c7 47 10 00 00 00    movq   $0x0,0x10(%rdi)
       84d17:       00
       84d18:       c3                      retq
       84d19:       0f 1f 80 00 00 00 00    nopl   0x0(%rax)
    
    0000000000084d20 <bar>:
       84d20:       48 8b 47 10             mov    0x10(%rdi),%rax
       84d24:       48 83 f8 05             cmp    $0x5,%rax
       84d28:       b9 05 00 00 00          mov    $0x5,%ecx
       84d2d:       48 0f 42 c8             cmovb  %rax,%rcx
       84d31:       48 89 4f 10             mov    %rcx,0x10(%rdi)
       84d35:       c3                      retq
       84d36:       66 2e 0f 1f 84 00 00    nopw   %cs:0x0(%rax,%rax,1)
       84d3d:       00 00 00
    
    0000000000084d40 <baz>:
       84d40:       48 8b 47 10             mov    0x10(%rdi),%rax
       84d44:       48 39 f0                cmp    %rsi,%rax
       84d47:       48 0f 47 c6             cmova  %rsi,%rax
       84d4b:       48 89 47 10             mov    %rax,0x10(%rdi)
       84d4f:       c3                      retq
    
    0000000000084d50 <foo_string>:
       84d50:       41 57                   push   %r15
       84d52:       41 56                   push   %r14
       84d54:       53                      push   %rbx
       84d55:       49 89 fe                mov    %rdi,%r14
       84d58:       4c 8b 7f 10             mov    0x10(%rdi),%r15
       84d5c:       4d 85 ff                test   %r15,%r15
       84d5f:       74 2f                   je     84d90 <foo_string+0x40>
       84d61:       49 8b 06                mov    (%r14),%rax
       84d64:       4b 8d 0c 7f             lea    (%r15,%r15,2),%rcx
       84d68:       48 8d 1c c8             lea    (%rax,%rcx,8),%rbx
       84d6c:       48 83 c3 f0             add    $0xfffffffffffffff0,%rbx
       84d70:       48 8b 33                mov    (%rbx),%rsi
       84d73:       48 85 f6                test   %rsi,%rsi
       84d76:       74 0e                   je     84d86 <foo_string+0x36>
       84d78:       48 8b 7b f8             mov    -0x8(%rbx),%rdi
       84d7c:       ba 01 00 00 00          mov    $0x1,%edx
       84d81:       e8 1a b1 ff ff          callq  7fea0 <__rust_dealloc@plt>
       84d86:       48 83 c3 e8             add    $0xffffffffffffffe8,%rbx
       84d8a:       49 83 c7 ff             add    $0xffffffffffffffff,%r15
       84d8e:       75 e0                   jne    84d70 <foo_string+0x20>
       84d90:       49 c7 46 10 00 00 00    movq   $0x0,0x10(%r14)
       84d97:       00
       84d98:       5b                      pop    %rbx
       84d99:       41 5e                   pop    %r14
       84d9b:       41 5f                   pop    %r15
       84d9d:       c3                      retq
       84d9e:       66 90                   xchg   %ax,%ax
    
    0000000000084da0 <bar_string>:
       84da0:       41 57                   push   %r15
       84da2:       41 56                   push   %r14
       84da4:       53                      push   %rbx
       84da5:       49 89 fe                mov    %rdi,%r14
       84da8:       4c 8b 7f 10             mov    0x10(%rdi),%r15
       84dac:       49 83 ff 06             cmp    $0x6,%r15
       84db0:       72 44                   jb     84df6 <bar_string+0x56>
       84db2:       49 8b 06                mov    (%r14),%rax
       84db5:       4b 8d 0c 7f             lea    (%r15,%r15,2),%rcx
       84db9:       48 8d 1c c8             lea    (%rax,%rcx,8),%rbx
       84dbd:       48 83 c3 f0             add    $0xfffffffffffffff0,%rbx
       84dc1:       49 83 c7 fb             add    $0xfffffffffffffffb,%r15
       84dc5:       66 2e 0f 1f 84 00 00    nopw   %cs:0x0(%rax,%rax,1)
       84dcc:       00 00 00
       84dcf:       90                      nop
       84dd0:       48 8b 33                mov    (%rbx),%rsi
       84dd3:       48 85 f6                test   %rsi,%rsi
       84dd6:       74 0e                   je     84de6 <bar_string+0x46>
       84dd8:       48 8b 7b f8             mov    -0x8(%rbx),%rdi
       84ddc:       ba 01 00 00 00          mov    $0x1,%edx
       84de1:       e8 ba b0 ff ff          callq  7fea0 <__rust_dealloc@plt>
       84de6:       48 83 c3 e8             add    $0xffffffffffffffe8,%rbx
       84dea:       49 83 c7 ff             add    $0xffffffffffffffff,%r15
       84dee:       75 e0                   jne    84dd0 <bar_string+0x30>
       84df0:       41 bf 05 00 00 00       mov    $0x5,%r15d
       84df6:       4d 89 7e 10             mov    %r15,0x10(%r14)
       84dfa:       5b                      pop    %rbx
       84dfb:       41 5e                   pop    %r14
       84dfd:       41 5f                   pop    %r15
       84dff:       c3                      retq
    
    0000000000084e00 <baz_string>:
       84e00:       41 57                   push   %r15
       84e02:       41 56                   push   %r14
       84e04:       41 54                   push   %r12
       84e06:       53                      push   %rbx
       84e07:       50                      push   %rax
       84e08:       49 89 ff                mov    %rdi,%r15
       84e0b:       48 8b 47 10             mov    0x10(%rdi),%rax
       84e0f:       49 89 c4                mov    %rax,%r12
       84e12:       49 29 f4                sub    %rsi,%r12
       84e15:       76 3c                   jbe    84e53 <baz_string+0x53>
       84e17:       49 89 f6                mov    %rsi,%r14
       84e1a:       49 8b 0f                mov    (%r15),%rcx
       84e1d:       48 8d 04 40             lea    (%rax,%rax,2),%rax
       84e21:       48 8d 1c c1             lea    (%rcx,%rax,8),%rbx
       84e25:       48 83 c3 f0             add    $0xfffffffffffffff0,%rbx
       84e29:       0f 1f 80 00 00 00 00    nopl   0x0(%rax)
       84e30:       48 8b 33                mov    (%rbx),%rsi
       84e33:       48 85 f6                test   %rsi,%rsi
       84e36:       74 0e                   je     84e46 <baz_string+0x46>
       84e38:       48 8b 7b f8             mov    -0x8(%rbx),%rdi
       84e3c:       ba 01 00 00 00          mov    $0x1,%edx
       84e41:       e8 5a b0 ff ff          callq  7fea0 <__rust_dealloc@plt>
       84e46:       48 83 c3 e8             add    $0xffffffffffffffe8,%rbx
       84e4a:       49 83 c4 ff             add    $0xffffffffffffffff,%r12
       84e4e:       75 e0                   jne    84e30 <baz_string+0x30>
       84e50:       4c 89 f0                mov    %r14,%rax
       84e53:       49 89 47 10             mov    %rax,0x10(%r15)
       84e57:       48 83 c4 08             add    $0x8,%rsp
       84e5b:       5b                      pop    %rbx
       84e5c:       41 5c                   pop    %r12
       84e5e:       41 5e                   pop    %r14
       84e60:       41 5f                   pop    %r15
       84e62:       c3                      retq
       84e63:       90                      nop
       84e64:       66 2e 0f 1f 84 00 00    nopw   %cs:0x0(%rax,%rax,1)
       84e6b:       00 00 00
       84e6e:       66 90                   xchg   %ax,%ax
    ```
    </details>
    
    For calling `truncate` with non-zero lengths on non-`Drop` types, it seems that a redundant load and comparison gets replaced with an awkward sequence with a conditional move. In the unknown length case, the new code is no longer awkward.
    
    Maybe someone moderately proficient at assembly could tell if this looks like a win or not.
    
    ---
    
    This came up when discussing replacing `unsafe { vec.set_len(0) }` with `vec.clear()` in a project where the author was worried about potential performance degradation. It might be worth replacing some unsafe code, even it it's trivial to see that it's actually safe.
    pietroalbini committed Aug 1, 2018
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  18. Rollup merge of rust-lang#52915 - Zoxc:refine-gen-borrow-analysis, r=…

    …eddyb
    
    Don't count MIR locals as borrowed after StorageDead when finding locals live across a yield terminator
    
    This should fix rust-lang#52792.
    
    r? @eddyb
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  19. Rollup merge of rust-lang#52926 - alexcrichton:trim-idioms-lints, r=o…

    …li-obk
    
    rustc: Trim down the `rust_2018_idioms` lint group
    
    These migration lints aren't all up to par in terms of a good migration
    experience. Some, like `unreachable_pub`, hit bugs like rust-lang#52665 and unprepared
    macros to be handled enough of the time. Others like linting against
    `#[macro_use]` are swimming upstream in an ecosystem that's not quite ready (and
    slightly buggy pending a few current PRs).
    
    The general idea is that we will continue to recommend the `rust_2018_idioms`
    lint group as part of the transition guide (as an optional step) but we'll be
    much more selective about which lints make it into this group. Only those with a
    strong track record of not causing too much churn will make the cut.
    
    cc rust-lang#52679
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  20. Rollup merge of rust-lang#52930 - eddyb:issue-52489, r=cramertj

    rustc_resolve: record single-segment extern crate import resolutions.
    
    Fixes rust-lang#52489 by recording special-cased single-segment imports for later (e.g. stability) checks.
    
    cc @alexcrichton @Mark-Simulacrum @petrochenkov
    
    Does this need to be backported?
    pietroalbini committed Aug 1, 2018
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  21. Rollup merge of rust-lang#52939 - ljedrz:fix_51746, r=kennytm

    Make io::Read::read_to_end consider io::Take::limit
    
    Add a custom implementation of `io::Read::read_to_end` for `io::Take` that doesn't reserve the default 32 bytes but rather `Take::limit` if `Take::limit < 32`.
    
    It's a conservative adjustment that preserves the default behavior for `Take::limit >= 32`.
    
    Fixes rust-lang#51746.
    pietroalbini committed Aug 1, 2018
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  22. Rollup merge of rust-lang#52942 - llogiq:smallvec-opt, r=Mark-Simulacrum

    Another SmallVec.extend optimization
    
    This improves SmallVec.extend even more over rust-lang#52859 while making the code easier to read.
    
    Before
    
    ```
    test small_vec::tests::fill_small_vec_1_10_with_cap  ... bench:          31 ns/iter (+/- 5)
    test small_vec::tests::fill_small_vec_1_10_wo_cap    ... bench:          70 ns/iter (+/- 4)
    test small_vec::tests::fill_small_vec_1_50_with_cap  ... bench:          36 ns/iter (+/- 3)
    test small_vec::tests::fill_small_vec_1_50_wo_cap    ... bench:         256 ns/iter (+/- 17)
    test small_vec::tests::fill_small_vec_32_10_with_cap ... bench:          31 ns/iter (+/- 5)
    test small_vec::tests::fill_small_vec_32_10_wo_cap   ... bench:          26 ns/iter (+/- 1)
    test small_vec::tests::fill_small_vec_32_50_with_cap ... bench:          49 ns/iter (+/- 4)
    test small_vec::tests::fill_small_vec_32_50_wo_cap   ... bench:         219 ns/iter (+/- 11)
    test small_vec::tests::fill_small_vec_8_10_with_cap  ... bench:          32 ns/iter (+/- 2)
    test small_vec::tests::fill_small_vec_8_10_wo_cap    ... bench:          61 ns/iter (+/- 12)
    test small_vec::tests::fill_small_vec_8_50_with_cap  ... bench:          37 ns/iter (+/- 3)
    test small_vec::tests::fill_small_vec_8_50_wo_cap    ... bench:         210 ns/iter (+/- 10)
    ```
    
    After:
    
    ```
    test small_vec::tests::fill_small_vec_1_10_wo_cap    ... bench:          31 ns/iter (+/- 3)
    test small_vec::tests::fill_small_vec_1_50_with_cap  ... bench:          39 ns/iter (+/- 4)
    test small_vec::tests::fill_small_vec_1_50_wo_cap    ... bench:          35 ns/iter (+/- 4)
    test small_vec::tests::fill_small_vec_32_10_with_cap ... bench:          37 ns/iter (+/- 3)
    test small_vec::tests::fill_small_vec_32_10_wo_cap   ... bench:          32 ns/iter (+/- 2)
    test small_vec::tests::fill_small_vec_32_50_with_cap ... bench:          52 ns/iter (+/- 4)
    test small_vec::tests::fill_small_vec_32_50_wo_cap   ... bench:          46 ns/iter (+/- 0)
    test small_vec::tests::fill_small_vec_8_10_with_cap  ... bench:          35 ns/iter (+/- 4)
    test small_vec::tests::fill_small_vec_8_10_wo_cap    ... bench:          31 ns/iter (+/- 0)
    test small_vec::tests::fill_small_vec_8_50_with_cap  ... bench:          40 ns/iter (+/- 15)
    test small_vec::tests::fill_small_vec_8_50_wo_cap    ... bench:          36 ns/iter (+/- 2)
    ```
    pietroalbini committed Aug 1, 2018
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  23. Rollup merge of rust-lang#52947 - Susurrus:patch-1, r=alexcrichton

    1.27 actually added the `armv5te-unknown-linux-musleabi` target
    
    The PR title says `armv5te-unknown-linux-musl`, but it looks like the final code merge renamed the target to `armv5te-unknown-linux-musleabi`. `rustup` reports this as correct as well.
    
    The [Rust Platform Support](https://forge.rust-lang.org/platform-support.html) page needs this added as well, but I'm not certain what codebase that is generated from.
    pietroalbini committed Aug 1, 2018
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  24. Configuration menu
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