ICE: codegenprepare pass segfaults

Code

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

Compiling the above with rustc -C no-prepopulate-passes -C passes=codegenprepare main.rs segfaults.

A similar issue also happens with ´codegenprepare´.

Meta

rustc --version --verbose:

rustc 1.87.0-nightly (f5a1ef712 2025-03-07)
binary: rustc
commit-hash: f5a1ef7121ad661b5a21a1d02941c8064d54ee0b
commit-date: 2025-03-07
host: x86_64-unknown-linux-gnu
release: 1.87.0-nightly
LLVM version: 20.1.0

Error output

error: rustc interrupted by SIGSEGV, printing backtrace

/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-e3b06f91230294e6.so(+0x374941f) [0x751f65d4941f]
/usr/lib/libc.so.6(+0x3dcd0) [0x751f6244bcd0]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/libLLVM.so.20.1-rust-1.87.0-nightly(+0x82a6c05) [0x751f60aa6c05]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/libLLVM.so.20.1-rust-1.87.0-nightly(_ZN4llvm18CodeGenPreparePass3runERNS_8FunctionERNS_15AnalysisManagerIS1_JEEE+0x190) [0x751f5e00cec0]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/libLLVM.so.20.1-rust-1.87.0-nightly(+0x6a6226d) [0x751f5f26226d]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/libLLVM.so.20.1-rust-1.87.0-nightly(_ZN4llvm11PassManagerINS_8FunctionENS_15AnalysisManagerIS1_JEEEJEE3runERS1_RS3_+0x70d) [0x751f60619b69]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/libLLVM.so.20.1-rust-1.87.0-nightly(_ZN4llvm27ModuleToFunctionPassAdaptor3runERNS_6ModuleERNS_15AnalysisManagerIS1_JEEE+0x296) [0x751f6068b728]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/libLLVM.so.20.1-rust-1.87.0-nightly(+0x7e8b48d) [0x751f6068b48d]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/libLLVM.so.20.1-rust-1.87.0-nightly(_ZN4llvm11PassManagerINS_6ModuleENS_15AnalysisManagerIS1_JEEEJEE3runERS1_RS3_+0x21f) [0x751f60d2fe5f]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-e3b06f91230294e6.so(+0x5e323c1) [0x751f684323c1]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-e3b06f91230294e6.so(+0x5e2b818) [0x751f6842b818]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-e3b06f91230294e6.so(_RNvXs1_Cs4GJg65wqyXp_18rustc_codegen_llvmNtB5_18LlvmCodegenBackendNtNtNtCs2qsHfWh5y4Q_17rustc_codegen_ssa6traits5write19WriteBackendMethods8optimize+0x186) [0x751f6839fce4]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-e3b06f91230294e6.so(_RINvNtNtCsaJNBDtcVlXq_3std3sys9backtrace28___rust_begin_short_backtraceNCINvXs0_Cs4GJg65wqyXp_18rustc_codegen_llvmNtB1g_18LlvmCodegenBackendNtNtNtCs2qsHfWh5y4Q_17rustc_codegen_ssa6traits7backend19ExtraBackendMethods18spawn_named_threadNCINvNtNtB2k_4back5write10spawn_workB1O_E0uE0uEB1g_+0x187) [0x751f6839c5c7]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-e3b06f91230294e6.so(+0x5d95edc) [0x751f68395edc]
/home/thomas/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-e3b06f91230294e6.so(+0x5d96277) [0x751f68396277]
/usr/lib/libc.so.6(+0x9570a) [0x751f624a370a]
/usr/lib/libc.so.6(+0x119aac) [0x751f62527aac]

note: we would appreciate a report at https://github.com/rust-lang/rust
help: you can increase rustc's stack size by setting RUST_MIN_STACK=16777216
[1]    445041 segmentation fault (core dumped)  rustc -C no-prepopulate-passes -C passes=codegenprepare a.rs

Reproduce the crash with the reported rustc command and nightly toolchain, then follow the backtrace into LLVM's CodeGenPreparePass. The issue is resolved when compiling the minimal Rust program with these flags no longer segfaults.