rustc: Add an unstable `simd_select_bitmask` intrinsic #56789

alexcrichton · 2018-12-13T20:52:13Z

This is going to be required for binding a number of AVX-512 intrinsics
in the stdsimd repository, and this intrinsic is the same as
simd_select except that it takes a bitmask as the first argument
instead of a SIMD vector. This bitmask is then transmuted into a <NN x i8> argument, depending on how many bits it is.

cc rust-lang/stdarch#310

rust-highfive · 2018-12-13T20:52:25Z

r? @michaelwoerister

(rust_highfive has picked a reviewer for you, use r? to override)

hanna-kruppe

Two nits, but otherwise LGTM

src/librustc_codegen_llvm/intrinsic.rs

hanna-kruppe · 2018-12-13T21:19:42Z

src/librustc_codegen_llvm/intrinsic.rs

+        let in_ty = arg_tys[0];
+        let m_len = match in_ty.sty {
+            ty::Int(i) => i.bit_width().unwrap(),
+            ty::Uint(i) => i.bit_width().unwrap(),


I think this will crash with usize/isize? Probably not a big issue but could be avoided by computing the layout.

It will indeed! That was semi-intentional, but I'll leave a comment in case a future reader is curious

Might be better to properly error here?

Hm perhaps yeah, but this is all internal anyway so I don't think we really need to go too far out of our way...

alexcrichton · 2018-12-13T22:06:18Z

@bors: r=rkruppe

bors · 2018-12-13T22:06:19Z

📌 Commit 5087aef has been approved by rkruppe

gnzlbg

LGTM.

gnzlbg · 2018-12-13T22:08:28Z

src/test/ui/simd-intrinsic/simd-intrinsic-generic-select.rs

+        //~^ ERROR `f32` is not an integral type
+
+        simd_select_bitmask("x", x, x);
+        //~^ ERROR `&str` is not an integral type


Might want to add a test for when the vector is not a SIMD type (probably for simd_select as well).

I think #[repr(simd)] is gating that, right?

I think @gnzlbg means the case when the second/third argument is not a repr(simd) type. That would exercise the require_simd! check in the intrinsic implementation.

Ah indeed, tests added now!

gnzlbg · 2018-12-13T22:09:45Z

src/librustc_codegen_llvm/intrinsic.rs

+        let in_ty = arg_tys[0];
+        let m_len = match in_ty.sty {
+            ty::Int(i) => i.bit_width().unwrap(),
+            ty::Uint(i) => i.bit_width().unwrap(),


Might be better to properly error here?

src/librustc_codegen_llvm/intrinsic.rs

…=rkruppe rustc: Add an unstable `simd_select_bitmask` intrinsic This is going to be required for binding a number of AVX-512 intrinsics in the `stdsimd` repository, and this intrinsic is the same as `simd_select` except that it takes a bitmask as the first argument instead of a SIMD vector. This bitmask is then transmuted into a `<NN x i8>` argument, depending on how many bits it is. cc rust-lang/stdarch#310

@ghost

Rollup of 14 pull requests (first batch) Successful merges: - #56562 (Update libc version required by rustc) - #56609 (Unconditionally emit the target-cpu LLVM attribute.) - #56637 (rustdoc: Fix local reexports of proc macros) - #56658 (Add non-panicking `maybe_new_parser_from_file` variant) - #56695 (Fix irrefutable matches on integer ranges) - #56699 (Use a `newtype_index!` within `Symbol`.) - #56702 ([self-profiler] Add column for percent of total time) - #56708 (Remove some unnecessary feature gates) - #56709 (Remove unneeded extra chars to reduce search-index size) - #56744 (specialize: remove Boxes used by Children::insert) - #56748 (Update panic message to be clearer about env-vars) - #56749 (x86: Add the `adx` target feature to whitelist) - #56756 (Disable btree pretty-printers on older gdbs) - #56789 (rustc: Add an unstable `simd_select_bitmask` intrinsic) r? @ghost

alexcrichton · 2018-12-14T16:49:31Z

@bors: r=rkruppe

bors · 2018-12-14T16:49:32Z

📌 Commit c6b645c76d3930461a73b3fd96de514099e19051 has been approved by rkruppe

alexcrichton · 2018-12-14T17:49:38Z

@bors: r=rkruppe

bors · 2018-12-14T17:49:38Z

📌 Commit bb31d607d4154c0f9ff2c2e5877ba567cf962a6c has been approved by rkruppe

bors · 2018-12-14T18:51:42Z

☔ The latest upstream changes (presumably #56818) made this pull request unmergeable. Please resolve the merge conflicts.

This is going to be required for binding a number of AVX-512 intrinsics in the `stdsimd` repository, and this intrinsic is the same as `simd_select` except that it takes a bitmask as the first argument instead of a SIMD vector. This bitmask is then transmuted into a `<NN x i8>` argument, depending on how many bits it is. cc rust-lang/stdarch#310

alexcrichton · 2018-12-14T19:18:06Z

@bors: r=rkruppe

Part of this landed in #56818 but I'd force pushed since this was rolled up, so this now includes just changes since the rollup

bors · 2018-12-14T19:18:07Z

📌 Commit ceee7f3 has been approved by rkruppe

alexcrichton · 2018-12-15T19:19:36Z

@bors: rollup

…=rkruppe rustc: Add an unstable `simd_select_bitmask` intrinsic This is going to be required for binding a number of AVX-512 intrinsics in the `stdsimd` repository, and this intrinsic is the same as `simd_select` except that it takes a bitmask as the first argument instead of a SIMD vector. This bitmask is then transmuted into a `<NN x i8>` argument, depending on how many bits it is. cc rust-lang/stdarch#310

@ghost

Rollup of 20 pull requests Successful merges: - #53506 (Documentation for impl From for AtomicBool and other Atomic types) - #56343 (Remove not used mod) - #56439 (Clearer error message for dead assign) - #56640 (Add FreeBSD unsigned char platforms to std::os::raw) - #56648 (Fix BTreeMap UB) - #56672 (Document time of back operations of a Linked List) - #56706 (Make `const unsafe fn` bodies `unsafe`) - #56742 (infer: remove Box from a returned Iterator) - #56761 (Suggest using `.display()` when trying to print a `Path`) - #56781 (Update LLVM submodule) - #56789 (rustc: Add an unstable `simd_select_bitmask` intrinsic) - #56790 (Make RValue::Discriminant a normal Shallow read) - #56793 (rustdoc: look for comments when scraping attributes/crates from doctests) - #56826 (rustc: Add the `cmpxchg16b` target feature on x86/x86_64) - #56832 (std: Use `rustc_demangle` from crates.io) - #56844 (Improve CSS rule) - #56850 (Fixed issue with using `Self` ctor in typedefs) - #56855 (Remove u8 cttz hack) - #56857 (Fix a small mistake regarding NaNs in a deprecation message) - #56858 (Fix doc of `std::fs::canonicalize`) Failed merges: - #56741 (treat ref-to-raw cast like a reborrow: do a special kind of retag) r? @ghost

rust-highfive assigned michaelwoerister Dec 13, 2018

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Dec 13, 2018

alexcrichton mentioned this pull request Dec 13, 2018

Implement AVX-512 intrinsics rust-lang/stdarch#310

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hanna-kruppe reviewed Dec 13, 2018

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alexcrichton force-pushed the simd_select_bitmask branch from 72aebb1 to 5087aef Compare December 13, 2018 22:05

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 Dec 13, 2018

gnzlbg approved these changes Dec 13, 2018

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kennytm mentioned this pull request Dec 14, 2018

Rollup of 36 pull requests #56803

Closed

This was referenced Dec 14, 2018

Rollup of 14 pull requests #56816

Closed

Rollup of 14 pull requests (first batch) #56818

Merged

alexcrichton force-pushed the simd_select_bitmask branch from 5087aef to c6b645c Compare December 14, 2018 16:48

alexcrichton force-pushed the simd_select_bitmask branch from c6b645c to bb31d60 Compare December 14, 2018 17:49

bors added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Dec 14, 2018

alexcrichton force-pushed the simd_select_bitmask branch from bb31d60 to ceee7f3 Compare December 14, 2018 19:17

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-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Dec 14, 2018

Centril mentioned this pull request Dec 16, 2018

Rollup of 22 pull requests #56873

Closed

Centril mentioned this pull request Dec 16, 2018

Rollup of 20 pull requests #56875

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bors merged commit ceee7f3 into rust-lang:master Dec 16, 2018

alexcrichton deleted the simd_select_bitmask branch December 17, 2018 02:59

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rustc: Add an unstable `simd_select_bitmask` intrinsic #56789

rustc: Add an unstable `simd_select_bitmask` intrinsic #56789

alexcrichton commented Dec 13, 2018

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rustc: Add an unstable simd_select_bitmask intrinsic #56789

rustc: Add an unstable simd_select_bitmask intrinsic #56789

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alexcrichton commented Dec 14, 2018

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alexcrichton commented Dec 15, 2018

rustc: Add an unstable `simd_select_bitmask` intrinsic #56789

rustc: Add an unstable `simd_select_bitmask` intrinsic #56789