Repository: rust
Issue: LLVM produces SIGILL when enabling avx2 target feature on `x86_64-unknown-none`
Labels: T-compiler,C-bug,A-target-feature

### Steps to reproduce

``` console
$ cargo new --lib repro
$ cd repro

$ echo '#![no_std]' > src/lib.rs
$ cargo add poly1305@0.8.0

$ rustup default 1.73.0
$ rustup target add x86_64-unknown-none
$ cargo b --target x86_64-unknown-none
error: could not compile `poly1305` (lib)

Caused by:
  process didn't exit successfully: `$RUSTUP_TOOLCHAIN/bin/rustc (..)` (signal: 4, SIGILL: illegal instruction)
```

Running `gdb --args $RUSTC_INVOCATION_PRINTED_BY_CARGO` produces this backtrace:


<details><summary>Stable Backtrace</summary>
<p>

```
Thread 7 "opt cgu.1" received signal SIGILL, Illegal instruction.
[Switching to Thread 0x7fffe11ff6c0 (LWP 102419)]
0x00007ffff13c939f in llvm::X86TargetLowering::ReplaceNodeResults(llvm::SDNode*, llvm::SmallVectorImpl<llvm::SDValue>&, llvm::SelectionDAG&) const [clone .cold.0] ()
   from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.73.0-stable.so
(gdb) backtrace
#0  0x00007ffff13c939f in llvm::X86TargetLowering::ReplaceNodeResults(llvm::SDNode*, llvm::SmallVectorImpl<llvm::SDValue>&, llvm::SelectionDAG&) const [clone .cold.0] ()
   from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.73.0-stable.so
#1  0x00007ffff1130ef5 in llvm::DAGTypeLegalizer::SplitVectorResult(llvm::SDNode*, unsigned int) [clone .cold.0] () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.73.0-stable.so
#2  0x00007ffff000d41a in llvm::DAGTypeLegalizer::run() () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.73.0-stable.so
#3  0x00007ffff01ff81a in llvm::SelectionDAGISel::SelectBasicBlock(llvm::ilist_iterator<llvm::ilist_detail::node_options<llvm::Instruction, false, false, void>, false, true>, llvm::ilist_iterator<llvm::ilist_detail::node_options<llvm::Instruction, false, false, void>, false, true>, bool&) () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.73.0-stable.so
#4  0x00007ffff04ff282 in llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.73.0-stable.so
#5  0x00007ffff034fc0a in llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.73.0-stable.so
#6  0x00007ffff034f4ee in (anonymous namespace)::X86DAGToDAGISel::runOnMachineFunction(llvm::MachineFunction&) [clone .llvm.6232165262612102610] () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.73.0-stable.so
#7  0x00007ffff016d66a in llvm::FPPassManager::runOnModule(llvm::Module&) () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.73.0-stable.so
#8  0x00007ffff05dcaac in llvm::legacy::PassManagerImpl::run(llvm::Module&) () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.73.0-stable.so
#9  0x00007ffff64d36a6 in LLVMRustWriteOutputFile () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-453cf35e1dd187fa.so
#10 0x00007ffff64d2558 in rustc_codegen_llvm[13e834ec38ef84a5]::back::write::write_output_file () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-453cf35e1dd187fa.so
#11 0x00007ffff64cfcd4 in rustc_codegen_llvm[13e834ec38ef84a5]::back::write::codegen () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-453cf35e1dd187fa.so
#12 0x00007ffff64cd074 in rustc_codegen_ssa[1239057ba2d16fcb]::back::write::finish_intra_module_work::<rustc_codegen_llvm[13e834ec38ef84a5]::LlvmCodegenBackend> () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-453cf35e1dd187fa.so
#13 0x00007ffff64cc75d in rustc_codegen_ssa[1239057ba2d16fcb]::back::write::execute_optimize_work_item::<rustc_codegen_llvm[13e834ec38ef84a5]::LlvmCodegenBackend> () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-453cf35e1dd187fa.so
#14 0x00007ffff64ca627 in std[3759e478f3a6c4f2]::sys_common::backtrace::__rust_begin_short_backtrace::<<rustc_codegen_llvm[13e834ec38ef84a5]::LlvmCodegenBackend as rustc_codegen_ssa[1239057ba2d16fcb]::traits::backend::ExtraBackendMethods>::spawn_named_thread<rustc_codegen_ssa[1239057ba2d16fcb]::back::write::spawn_work<rustc_codegen_llvm[13e834ec38ef84a5]::LlvmCodegenBackend>::{closure#0}, ()>::{closure#0}, ()> () from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-453cf35e1dd187fa.so
#15 0x00007ffff6459256 in <<std[3759e478f3a6c4f2]::thread::Builder>::spawn_unchecked_<<rustc_codegen_llvm[13e834ec38ef84a5]::LlvmCodegenBackend as rustc_codegen_ssa[1239057ba2d16fcb]::traits::backend::ExtraBackendMethods>::spawn_named_thread<rustc_codegen_ssa[1239057ba2d16fcb]::back::write::spawn_work<rustc_codegen_llvm[13e834ec38ef84a5]::LlvmCodegenBackend>::{closure#0}, ()>::{closure#0}, ()>::{closure#1} as core[d28c4e8d9c4eebaa]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0} ()
   from /home/japaric/.rustup/toolchains/1.73.0-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-453cf35e1dd187fa.so
#16 0x00007ffff3d71295 in alloc::boxed::{impl#47}::call_once<(), dyn core::ops::function::FnOnce<(), Output=()>, alloc::alloc::Global> () at library/alloc/src/boxed.rs:2007
#17 alloc::boxed::{impl#47}::call_once<(), alloc::boxed::Box<dyn core::ops::function::FnOnce<(), Output=()>, alloc::alloc::Global>, alloc::alloc::Global> () at library/alloc/src/boxed.rs:2007
#18 std::sys::unix::thread::{impl#2}::new::thread_start () at library/std/src/sys/unix/thread.rs:108
#19 0x00007ffff3ae59eb in ?? () from /usr/lib/libc.so.6
#20 0x00007ffff3b697cc in ?? () from /usr/lib/libc.so.6
```

</p>
</details>

---

Using `nightly-2023-11-15` toolchain produces a "LLVM ERROR" instead:

``` console
$ cargo +nightly-2023-11-15 b --target x86_64-unknown-none
LLVM ERROR: Do not know how to split the result of this operator!

error: could not compile `poly1305` (lib)
```

Unless the `--release` flag is used, then you get the SIGILL with the nightly toolchain. The backtrace appears to be similar to the stable toolchain one:


<details><summary>Nightly Backtrace</summary>
<p>

```
(gdb) backtrace
#0  0x00007ffff12744ca in llvm::X86TargetLowering::ReplaceNodeResults(llvm::SDNode*, llvm::SmallVectorImpl<llvm::SDValue>&, llvm::SelectionDAG&) const [clone .cold.0] ()
   from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.76.0-nightly.so
#1  0x00007ffff133a1ce in llvm::DAGTypeLegalizer::SplitVectorResult(llvm::SDNode*, unsigned int) [clone .cold.0] () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.76.0-nightly.so
#2  0x00007ffff020e085 in llvm::DAGTypeLegalizer::run() () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.76.0-nightly.so
#3  0x00007ffff03a8ada in llvm::SelectionDAGISel::CodeGenAndEmitDAG() () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.76.0-nightly.so
#4  0x00007ffff09c09b8 in llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.76.0-nightly.so
#5  0x00007ffff05f27fa in llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.76.0-nightly.so
#6  0x00007ffff05f2016 in (anonymous namespace)::X86DAGToDAGISel::runOnMachineFunction(llvm::MachineFunction&) [clone .llvm.4022770523405222600] () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.76.0-nightly.so
#7  0x00007ffff034e3c1 in llvm::FPPassManager::runOnFunction(llvm::Function&) () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.76.0-nightly.so
#8  0x00007ffff034d947 in llvm::FPPassManager::runOnModule(llvm::Module&) () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.76.0-nightly.so
#9  0x00007ffff04e317a in llvm::legacy::PassManagerImpl::run(llvm::Module&) () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/../lib/libLLVM-17-rust-1.76.0-nightly.so
#10 0x00007ffff6b745d0 in LLVMRustWriteOutputFile () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-a2929300a34289e9.so
#11 0x00007ffff6b7420c in rustc_codegen_llvm[e0f834ca461547f0]::back::write::write_output_file () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-a2929300a34289e9.so
#12 0x00007ffff6b71bdf in rustc_codegen_llvm[e0f834ca461547f0]::back::write::codegen () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-a2929300a34289e9.so
#13 0x00007ffff6b7187f in rustc_codegen_ssa[130828829af41105]::back::write::finish_intra_module_work::<rustc_codegen_llvm[e0f834ca461547f0]::LlvmCodegenBackend> ()
   from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-a2929300a34289e9.so
#14 0x00007ffff6ccb32b in std[14019a58b7d275f1]::sys_common::backtrace::__rust_begin_short_backtrace::<<rustc_codegen_llvm[e0f834ca461547f0]::LlvmCodegenBackend as rustc_codegen_ssa[130828829af41105]::traits::backend::ExtraBackendMethods>::spawn_named_thread<rustc_codegen_ssa[130828829af41105]::back::write::spawn_work<rustc_codegen_llvm[e0f834ca461547f0]::LlvmCodegenBackend>::{closure#0}, ()>::{closure#0}, ()> () from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-a2929300a34289e9.so
#15 0x00007ffff6cca7e4 in <<std[14019a58b7d275f1]::thread::Builder>::spawn_unchecked_<<rustc_codegen_llvm[e0f834ca461547f0]::LlvmCodegenBackend as rustc_codegen_ssa[130828829af41105]::traits::backend::ExtraBackendMethods>::spawn_named_thread<rustc_codegen_ssa[130828829af41105]::back::write::spawn_work<rustc_codegen_llvm[e0f834ca461547f0]::LlvmCodegenBackend>::{closure#0}, ()>::{closure#0}, ()>::{closure#1} as core[a62a0f03b43184e2]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0} ()
   from /home/japaric/.rustup/toolchains/nightly-2023-11-15-x86_64-unknown-linux-gnu/bin/../lib/librustc_driver-a2929300a34289e9.so
#16 0x00007ffff1f98915 in alloc::boxed::{impl#47}::call_once<(), dyn core::ops::function::FnOnce<(), Output=()>, alloc::alloc::Global> () at library/alloc/src/boxed.rs:2007
#17 alloc::boxed::{impl#47}::call_once<(), alloc::boxed::Box<dyn core::ops::function::FnOnce<(), Output=()>, alloc::alloc::Global>, alloc::alloc::Global> () at library/alloc/src/boxed.rs:2007
#18 std::sys::unix::thread::{impl#2}::new::thread_start () at library/std/src/sys/unix/thread.rs:108
#19 0x00007ffff1d899eb in ?? () from /usr/lib/libc.so.6
#20 0x00007ffff1e0d7cc in ?? () from /usr/lib/libc.so.6
```

</p>
</details>


### Meta

Downstream discussion: https://github.com/RustCrypto/universal-hashes/issues/189

`rustc +1.73.0 --version --verbose`
```
rustc 1.73.0 (cc66ad468 2023-10-03)
binary: rustc
commit-hash: cc66ad468955717ab92600c770da8c1601a4ff33
commit-date: 2023-10-03
host: x86_64-unknown-linux-gnu
release: 1.73.0
LLVM version: 17.0.2
```

`rustc +nightly-2023-11-15 --version --verbose`

```
rustc 1.76.0-nightly (dd430bc8c 2023-11-14)
binary: rustc
commit-hash: dd430bc8c22f57992ec1457a87437d14283fdd65
commit-date: 2023-11-14
host: x86_64-unknown-linux-gnu
release: 1.76.0-nightly
LLVM version: 17.0.5
```