[ICE] "ty_size: unhandled type" when using a SIMD type in FFI

[kennytm]

Example code

#![allow(dead_code)]
use std::simd::u64x2;
extern {
    fn foo(a: u64x2);
}
fn main() {}

This fails with:

error: internal compiler error: unexpected panic
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: http://doc.rust-lang.org/complement-bugreport.html
note: run with `RUST_BACKTRACE=1` for a backtrace
task 'rustc' panicked at 'ty_size: unhandled type', /Users/rustbuild/src/rust-buildbot/slave/nightly-mac/build/src/librustc_trans/trans/cabi_x86_64.rs:146

stack backtrace:
   1:        0x104bd5130 - rt::backtrace::imp::write::h6bfacabc152a107af1x
   2:        0x104bd8721 - failure::on_fail::h004240af5c8bff3bWny
   3:        0x104e3ff55 - unwind::begin_unwind_inner::h2bc1d2ba239d03629Ec
   4:        0x101b6b22c - unwind::begin_unwind::h13950834142134723930
   5:        0x101cbcd0b - trans::cabi_x86_64::classify_ty::ty_size::hbc87c34bce054a64VNA
   6:        0x101cbc8f5 - trans::cabi_x86_64::classify_ty::h08570c25d40b0525vLA
   7:        0x101cba72f - trans::cabi::compute_abi_info::h195a5df35ad95172bwA
   8:        0x101cbe329 - trans::foreign::foreign_types_for_fn_ty::hd2c1e54723b16f79lMC
   9:        0x101c5901f - trans::foreign::register_foreign_item_fn::hb781bfb3ebdf946fsDB
  10:        0x101ba73c5 - trans::base::trans_item::heb324ea32fa423578Eu
  11:        0x101c6abb8 - trans::base::trans_crate::hba3b16755eb22180jBv
  12:        0x101406eae - driver::phase_4_translate_to_llvm::h9c2fab499036a1b9XCa
  13:        0x1013e0c58 - driver::compile_input::h8cefb00def448166rba
  14:        0x1015652c5 - run_compiler::hdf31023103b0c737AYb
  15:        0x10155b0dd - thunk::F.Invoke<A, R>::invoke::h6761157341938668982
  16:        0x104bade59 - thunk::F.Invoke<A, R>::invoke::h16129900982312133975
  17:        0x104e3e5c9 - task::Task::spawn_thunk::closure.5620
  18:        0x104ea72fc - rust_try_inner
  19:        0x104ea72e6 - rust_try
  20:        0x104e3e6b7 - unwind::try::h956380dd3aadd40dquc
  21:        0x104e3e45c - task::Task::run::h0dabcd2eaf1030d1oLb
  22:        0x104e3ddf4 - thunk::F.Invoke<A, R>::invoke::h356599560990785622
  23:        0x104e3f514 - thread::thread_start::h1abd83bbbd15cd00I2b
  24:     0x7fff87a8f2fc - _pthread_body
  25:     0x7fff87a8f279 - _pthread_body

$ rustc -v
rustc 0.13.0-nightly (42deaa5e4 2014-12-16 17:51:23 +0000)

[huonw]

cc me

This is unfortunate since one could probably use e.g. extern {#[link_name = "llvm.sqrt.f32"] fn vsqrt(x: f32x4); } as a hack to be able to use vector operations that aren't provided in any other way.