Minimal reproducible example for my Rust Issue from 2022-01 about Rustc/LLVM

rust-lang/rust#92760

This example shows that the problem that crashes Rustc/LLVM is not in hasbrown but in fact somewhere in fontdue.

See main.rs/entry_rust() for problematic code.

Build with § cargo build. It will output:
LLVM ERROR: Do not know how to split the result of this operator!

Update #1

• after disabling the simd-feature of fontdue the LLVM error message is gone and the error message is now:

-20220112-minimal-example/target/x86_64-none-bare_metal/debug/deps/kernel_bin-b2e3b701572fd441" "--gc-sections"
  = note: rust-lld: error: undefined symbol: fmaxf
          >>> referenced by f32.rs:690 (/home/pschuster/.rustup/toolchains/nightly-2022-01-03-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/num/f32.rs:690)
          >>>               /home/pschuster/dev/other/rust-llvm-bug-20220112-minimal-example/target/x86_64-none-bare_metal/debug/deps/kernel_bin-b2e3b701572fd441.4i8fwqz53syl3m5f.rcgu.o:(core::f32::_$LT$impl$u20$f32$GT$::max::h3b280365286bb855)
          >>> referenced by f32.rs:690 (/home/pschuster/.rustup/toolchains/nightly-2022-01-03-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/num/f32.rs:690)
          >>>               ttf_parser-6b7cd33f39fc07ca.ttf_parser.7b1c2514-cgu.7.rcgu.o:(core::f32::_$LT$impl$u20$f32$GT$::max::h8cf801bec5e7b913) in archive /home/pschuster/dev/other/rust-llvm-bug-20220112-minimal-example/target/x86_64-none-bare_metal/debug/deps/libttf_parser-6b7cd33f39fc07ca.rlib
          
          rust-lld: error: undefined symbol: fminf
          >>> referenced by f32.rs:709 (/home/pschuster/.rustup/toolchains/nightly-2022-01-03-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/num/f32.rs:709)
          >>>               /home/pschuster/dev/other/rust-llvm-bug-20220112-minimal-example/target/x86_64-none-bare_metal/debug/deps/kernel_bin-b2e3b701572fd441.4i8fwqz53syl3m5f.rcgu.o:(core::f32::_$LT$impl$u20$f32$GT$::min::h7f29acd76dc9436e)
          >>> referenced by f32.rs:709 (/home/pschuster/.rustup/toolchains/nightly-2022-01-03-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/num/f32.rs:709)
          >>>               ttf_parser-6b7cd33f39fc07ca.ttf_parser.7b1c2514-cgu.7.rcgu.o:(core::f32::_$LT$impl$u20$f32$GT$::min::h47ed670ba851f6e4) in archive /home/pschuster/dev/other/rust-llvm-bug-20220112-minimal-example/target/x86_64-none-bare_metal/debug/deps/libttf_parser-6b7cd33f39fc07ca.rlib

This is possibly linked to rust-lang/rust#62729

• Working workaround from that issue:

#[no_mangle]
fn fminf(a: f32, b: f32) -> f32 {
    if a < b {
        a
    } else {
        b
    }
}

#[no_mangle]
fn fmaxf(a: f32, b: f32) -> f32 {
    if a > b {
        a
    } else {
        b
    }
}```