regression: ICE in rustc_codegen_ssa/src/mir/rvalue.rs:104:55:

[Mark-Simulacrum]

https://crater-reports.s3.amazonaws.com/beta-1.86-3/beta-2025-02-28/gh/rodrimati1992.nlist/log.txt

[INFO] [stdout] thread 'rustc' panicked at /rustc/42212a5c45ab623e38a36a74ea288a2b0277b911/compiler/rustc_codegen_ssa/src/mir/rvalue.rs:104:55:
[INFO] [stdout] range end index 32 out of range for slice of length 16
[INFO] [stdout] stack backtrace:
[INFO] [stdout]    0:     0x77af5c7df1f0 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h109c0a3e31db436f
[INFO] [stdout]    1:     0x77af5d02e37c - core::fmt::write::hd3671829af6364f1
[INFO] [stdout]    2:     0x77af5e2f6c11 - std::io::Write::write_fmt::h09c0b55cb3c03365
[INFO] [stdout]    3:     0x77af5c7df052 - std::sys::backtrace::BacktraceLock::print::h0c74b492af7c203e
[INFO] [stdout]    4:     0x77af5c7e14d2 - std::panicking::default_hook::{{closure}}::ha3187647a2c71f3f
[INFO] [stdout]    5:     0x77af5c7e135a - std::panicking::default_hook::hd30ec41e71bae477
[INFO] [stdout]    6:     0x77af5b93cb49 - std[a34c84fb451aa647]::panicking::update_hook::<alloc[269605b11217779b]::boxed::Box<rustc_driver_impl[156b8d531ed2f52a]::install_ice_hook::{closure#1}>>::{closure#0}
[INFO] [stdout]    7:     0x77af5c7e2053 - std::panicking::rust_panic_with_hook::h27266a0abed10aa3
[INFO] [stdout]    8:     0x77af5c7e1d4a - std::panicking::begin_panic_handler::{{closure}}::h3b855edddb50a621
[INFO] [stdout]    9:     0x77af5c7df6d9 - std::sys::backtrace::__rust_end_short_backtrace::hd74a78f3727f3f2f
[INFO] [stdout]   10:     0x77af5c7e1a0d - rust_begin_unwind
[INFO] [stdout]   11:     0x77af5943e470 - core::panicking::panic_fmt::hfb8006ac977ca2c2
[INFO] [stdout]   12:     0x77af5b366f57 - core::slice::index::slice_end_index_len_fail::do_panic::runtime::hc91baf9025a5b3c7
[INFO] [stdout]   13:     0x77af5aae657a - core::slice::index::slice_end_index_len_fail::h2571e7225db81b15
[INFO] [stdout]   14:     0x77af5eaf377c - <rustc_codegen_ssa[2026626801868929]::mir::FunctionCx<rustc_codegen_llvm[69fa5b5ac59e4c59]::builder::GenericBuilder<rustc_codegen_llvm[69fa5b5ac59e4c59]::context::CodegenCx>>>::codegen_rvalue::{closure#0}.cold
[INFO] [stdout]   15:     0x77af5db34e75 - rustc_codegen_ssa[2026626801868929]::mir::codegen_mir::<rustc_codegen_llvm[69fa5b5ac59e4c59]::builder::GenericBuilder<rustc_codegen_llvm[69fa5b5ac59e4c59]::context::CodegenCx>>
[INFO] [stdout]   16:     0x77af5dadea48 - rustc_codegen_llvm[69fa5b5ac59e4c59]::base::compile_codegen_unit::module_codegen
[INFO] [stdout]   17:     0x77af5dfb4848 - <rustc_codegen_llvm[69fa5b5ac59e4c59]::LlvmCodegenBackend as rustc_codegen_ssa[2026626801868929]::traits::backend::ExtraBackendMethods>::compile_codegen_unit
[INFO] [stdout]   18:     0x77af5dfb0a97 - rustc_codegen_ssa[2026626801868929]::base::codegen_crate::<rustc_codegen_llvm[69fa5b5ac59e4c59]::LlvmCodegenBackend>
[INFO] [stdout]   19:     0x77af5dfafe2f - <rustc_codegen_llvm[69fa5b5ac59e4c59]::LlvmCodegenBackend as rustc_codegen_ssa[2026626801868929]::traits::backend::CodegenBackend>::codegen_crate
[INFO] [stdout]   20:     0x77af5dfb8fb4 - <rustc_interface[7875b19b4320107]::queries::Linker>::codegen_and_build_linker
[INFO] [stdout]   21:     0x77af5df6df9d - rustc_interface[7875b19b4320107]::passes::create_and_enter_global_ctxt::<core[24f9de5ae5e08215]::option::Option<rustc_interface[7875b19b4320107]::queries::Linker>, rustc_driver_impl[156b8d531ed2f52a]::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}
[INFO] [stdout]   22:     0x77af5df7e7e6 - rustc_interface[7875b19b4320107]::interface::run_compiler::<(), rustc_driver_impl[156b8d531ed2f52a]::run_compiler::{closure#0}>::{closure#1}
[INFO] [stdout]   23:     0x77af5de85f84 - std[a34c84fb451aa647]::sys::backtrace::__rust_begin_short_backtrace::<rustc_interface[7875b19b4320107]::util::run_in_thread_with_globals<rustc_interface[7875b19b4320107]::util::run_in_thread_pool_with_globals<rustc_interface[7875b19b4320107]::interface::run_compiler<(), rustc_driver_impl[156b8d531ed2f52a]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>
[INFO] [stdout]   24:     0x77af5de85c59 - <<std[a34c84fb451aa647]::thread::Builder>::spawn_unchecked_<rustc_interface[7875b19b4320107]::util::run_in_thread_with_globals<rustc_interface[7875b19b4320107]::util::run_in_thread_pool_with_globals<rustc_interface[7875b19b4320107]::interface::run_compiler<(), rustc_driver_impl[156b8d531ed2f52a]::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}, ()>::{closure#1} as core[24f9de5ae5e08215]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
[INFO] [stdout]   25:     0x77af5de853ef - std::sys::pal::unix::thread::Thread::new::thread_start::h671b94df33d4fdac
[INFO] [stdout]   26:     0x77af5f621ac3 - <unknown>
[INFO] [stdout]   27:     0x77af5f6b2a04 - clone
[INFO] [stdout]   28:                0x0 - <unknown>
[INFO] [stdout] 
[INFO] [stdout] error: the compiler unexpectedly panicked. this is a bug.
[INFO] [stdout] 
[INFO] [stdout] note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md
[INFO] [stdout] 
[INFO] [stdout] note: rustc 1.86.0-beta.3 (42212a5c4 2025-02-27) running on x86_64-unknown-linux-gnu

[compiler-errors]

Regressed in #135335, cc @oli-obk

[oli-obk]

I'll create a PR simply removing the opt. Then I'll reland on master seprately

[apiraino]

WG-prioritization assigning priority (Zulip discussion).

@rustbot label -I-prioritize +P-high

[wesleywiser]

Fix was backported to beta in #138190