Aarch64 LLVM internal error "Both operands to a binary operator are not of the same type"

[ogoffart]

Our CI system building artifact for aarch64 started to fail with the release of Rust 1.65

I tried to reduce the bug a bit:

main.rs

fn main() {

    let mut fontdb = fontdb::Database::new();
    fontdb.load_system_fonts();
    fontdb.query(&fontdb::Query { families: &[fontdb::Family::Name("xxx")], ..Default::default() })
        .and_then(|face_id| {
            fontdb.with_face_data(face_id, |_face_data, _face_index| {
                fontdue::Font::from_bytes( b"sfqsqsfqd".as_slice(), fontdue::FontSettings::default())
            })
    });

    let  fonts = Vec::<fontdb::ID>::new();
    let face_id = fonts.into_iter().next().unwrap();
    fontdb .with_face_data(face_id, |_font_data, _face_index| {
        fontdue::Font::from_bytes(b"".as_slice(), fontdue::FontSettings::default())
    });
}

Cargo.toml dependencies

[dependencies]
fontdue = "0.7.2"
fontdb = "0.9.3"

[profile.release]
lto = true

Build with

cargo build --release --target aarch64-unknown-linux-gnu

(same with --target aarch64-apple-darwin)

Since Rust 1.65, we get this error:

Both operands to a binary operator are not of the same type!
  %2414 = xor i64 %2413, i32 4
in function _ZN7fontdue4font4Font10from_bytes17h0d1adf483f24d13bE
LLVM ERROR: Broken function found, compilation aborted!

Can still be reproduced in nightly

[nikic]

I wasn't able to reproduce this (on either stable or nightly).

[ogoffart]

You're right, trying in a fresh project i couldn't reproduce. I realized the original Cargo.toml also contained a lto=true that was also necessary
I edited the original description to add

[profile.release]
lto = true

Thanks for looking into this.

[ogoffart]

Also, contrary to what i wrote initially, the bug appeared first in 1.65 (and not 1.64)

[nikic]

Thanks, I can reproduce the issue now. Reduced test case:

; RUN: llc < %s
target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
target triple = "aarch64-unknown-linux-gnu"

define void @test(i8 %arg) {
  %arg.ext = zext i8 %arg to i64
  %trunc = trunc i64 %arg.ext to i3
  %switch.tableidx = xor i3 %trunc, 1
  %switch.maskindex = zext i3 %trunc to i8
  %switch.lobit = icmp ne i8 %switch.maskindex, 0
  call void @llvm.assume(i1 %switch.lobit)
  %ext = zext i3 %switch.tableidx to i64
  ret void
}

declare void @llvm.assume(i1)

[nikic]

Upstream issue: llvm/llvm-project#58843

[fenhl]

The upstream issue appears to be fixed. What needs to be done now to apply this fix?