ICE in crate matrixmultiply with newest nightly

[DarkDrek]

Can't compile the crate matrixmultiply (https://crates.io/crates/matrixmultiply)
It seems to not compile anymore since this commit.
And the line assert!(mr * nr * size_of::<K::Elem>() <= 256 && K::align_to() <= 32); is the cause.

Minimal code to reproduce (playground)

use std::mem::size_of;

pub trait GemmKernel {
    type Elem;
}

pub type T = f32;

pub enum Gemm { }

impl GemmKernel for Gemm {
    type Elem = T;
}

fn gemm_packed<K>()
where
    K: GemmKernel,
{
    assert!(size_of::<K::Elem>() <= 256);
}

fn main() {
    println!("Hello, world!");
}

My system:
rustc 1.20.0-nightly (582af6e 2017-07-19) running on x86_64-unknown-linux-gnu
binary: rustc
commit-hash: 582af6e
commit-date: 2017-07-19
LLVM version: 4.0

Backtrace:
error: internal compiler error: /checkout/src/librustc/infer/mod.rs:573: Encountered errors [FulfillmentError(Obligation(predicate=Binder(TraitPredicate(<K as kernel::GemmKernel>)),depth=0),Unimplemented)] resolving bounds after type-checking

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.20.0-nightly (582af6e 2017-07-19) running on x86_64-unknown-linux-gnu

note: run with RUST_BACKTRACE=1 for a backtrace

thread 'rustc' panicked at 'Box', /checkout/src/librustc_errors/lib.rs:437:8
stack backtrace:
0: 0x7f9e7e1c5a03 - std::sys::imp::backtrace::tracing::imp::unwind_backtrace::h0155dbb6ca59ce6e
at /checkout/src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:49
1: 0x7f9e7e1c00e4 - std::sys_common::backtrace::_print::h5f4f2ec19ff00311
at /checkout/src/libstd/sys_common/backtrace.rs:71
2: 0x7f9e7e1d3883 - std::panicking::default_hook::{{closure}}::hafc0eefa360df4ab
at /checkout/src/libstd/sys_common/backtrace.rs:60
at /checkout/src/libstd/panicking.rs:380
3: 0x7f9e7e1d3578 - std::panicking::default_hook::h83538a8b6a433831
at /checkout/src/libstd/panicking.rs:390
4: 0x7f9e7e1d3d87 - std::panicking::rust_panic_with_hook::hae3224b5f6b814fd
at /checkout/src/libstd/panicking.rs:611
5: 0x7f9e7aeafeb8 - std::panicking::begin_panic_new::h6672f948a100c2a1
6: 0x7f9e7ae9a2a1 - rustc_errors::Handler::span_bug::hc43628812f7bb545
7: 0x7f9e7b0d84e3 - rustc::session::opt_span_bug_fmt::{{closure}}::h36f1c23dee0ab88c
8: 0x7f9e7b0d8202 - rustc::session::opt_span_bug_fmt::hb3234649816b9313
9: 0x7f9e7b0d80d3 - rustc::session::span_bug_fmt::h7088a0e5e41c572a
10: 0x7f9e7b19045f - <&'gcx rustc::ty::TyS<'gcx> as rustc::infer::TransNormalize<'gcx>>::trans_normalize::hf754271ad7f5ecb6
11: 0x7f9e7b05207d - rustc::infer::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'tcx>>::normalize_associated_type_in_env::h302f650510c2da58
12: 0x7f9e7b1325e1 - rustc::ty::layout::Layout::compute_uncached::h7f115120b7e746d8
13: 0x7f9e7b1565ca - rustc::ty::util::layout_raw::h8e132d2c99ca2da6
14: 0x7f9e7b1fd819 - rustc::ty::maps::<impl rustc::ty::maps::queries::layout_raw<'tcx>>::try_get::h00900307c9b08a50
15: 0x7f9e7b20a5ff - rustc::ty::maps::TyCtxtAt::layout_raw::hc104cf8d0b71516c
16: 0x7f9e7b20570d - rustc::ty::maps::<impl rustc::ty::context::TyCtxt<'a, 'tcx, 'lcx>>::layout_raw::had53de086a1553d2
17: 0x7f9e7ba73784 - rustc_const_eval::eval::eval_const_expr_partial::{{closure}}::hdf1b1c1933b44d19
18: 0x7f9e7ba6d933 - rustc_const_eval::eval::eval_const_expr_partial::h5a0fa592a92b3a61
19: 0x7f9e7ba6d5fb - rustc_const_eval::eval::eval_const_expr_partial::h5a0fa592a92b3a61
20: 0x7f9e7ba6d5fb - rustc_const_eval::eval::eval_const_expr_partial::h5a0fa592a92b3a61
21: 0x7f9e7ba70f72 - rustc_const_eval::eval::eval_const_expr_partial::h5a0fa592a92b3a61
22: 0x7f9e7ba6cca0 - rustc_const_eval::eval::ConstContext::eval::h383a143d122477ef
23: 0x7f9e7d93e740 - <rustc_passes::consts::CheckCrateVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr::hf35ee466267e49b2
24: 0x7f9e7d93e5d5 - <rustc_passes::consts::CheckCrateVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr::hf35ee466267e49b2
25: 0x7f9e7d93e228 - <rustc_passes::consts::CheckCrateVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr::hf35ee466267e49b2
26: 0x7f9e7d93e5d5 - <rustc_passes::consts::CheckCrateVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr::hf35ee466267e49b2
27: 0x7f9e7d93e2b7 - <rustc_passes::consts::CheckCrateVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr::hf35ee466267e49b2
28: 0x7f9e7d93e3c7 - <rustc_passes::consts::CheckCrateVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_expr::hf35ee466267e49b2
29: 0x7f9e7d93d0b9 - <rustc_passes::consts::CheckCrateVisitor<'a, 'tcx> as rustc::hir::intravisit::Visitor<'tcx>>::visit_nested_body::hefec5d46b6b699fa
30: 0x7f9e7d93eddc - rustc_passes::consts::check_crate::h923f5bb61e5540fc
31: 0x7f9e7e5754a5 - rustc_driver::driver::phase_3_run_analysis_passes::{{closure}}::h60b971f27694dab9
32: 0x7f9e7e56dbc3 - rustc_driver::driver::phase_3_run_analysis_passes::hd1ef7181394c7568
33: 0x7f9e7e54eecd - rustc_driver::driver::compile_input::h0c538d591196658d
34: 0x7f9e7e594195 - rustc_driver::run_compiler::h00b9147f2ffd288b
35: 0x7f9e7e4ad247 - std::sys_common::backtrace::__rust_begin_short_backtrace::hefa140dc360bd2e2
36: 0x7f9e7e2032cc - __rust_maybe_catch_panic
at /checkout/src/libpanic_unwind/lib.rs:98
37: 0x7f9e7e4e49b0 - <F as alloc::boxed::FnBox>::call_box::haaadeb4d67112a83
38: 0x7f9e7e1d277b - std::sys::imp::thread::Thread::new::thread_start::heb3ab1fa2e79a8b9
at /checkout/src/liballoc/boxed.rs:661
at /checkout/src/libstd/sys_common/thread.rs:21
at /checkout/src/libstd/sys/unix/thread.rs:84
39: 0x7f9e79382493 - start_thread
40: 0x7f9e7de85a8e - __clone
41: 0x0 -

error: Could not compile matrixmultiply.

[SpaceManiac]

Same as #43394

[alexcrichton]

Looks to be so!