Android/ARM: opt-level = 3 produces "LLVM ERROR: Constant Island pass failed to converge" on GNU/Linux

[alopatindev]

Building servo (7bd2381) for Android (./mach build --verbose --release --android) fails when compiling servo/.cargo/registry/src/github.com-88ac128001ac3a9a/cssparser-0.5.5/src/lib.rs

Environment: GNU/Linux, android-ndk-11c

$ ./mach rustc --version --verbose
rustc 1.9.0-nightly (241a9d0dd 2016-04-05)
binary: rustc
commit-hash: 241a9d0ddf99fd40d273c615e9b1e8ce6052d94a
commit-date: 2016-04-05
host: x86_64-unknown-linux-gnu
release: 1.9.0-nightly

Building output:

...
LLVM ERROR: Constant Island pass failed to converge!
Build failed, waiting for other jobs to finish...
error: Could not compile `cssparser`.
Caused by:
  Process didn't exit successfully: `rustc /home/sbar/git/servo/.cargo/registry/src/github.com-88ac128001ac3a9a/cssparser-0.5.5/src/lib.rs --crate-name cssparser --crate-type lib -C opt-level=3 -C codegen-units=4 --cfg feature="serde" --cfg feature="heap_size" --cfg feature="heapsize" --cfg feature="heapsize_plugin" --cfg feature="serde_macros" --cfg feature="serde-serialization" -C metadata=a00db9153a066bec -C extra-filename=-a00db9153a066bec --out-dir /home/sbar/git/servo/target/arm-linux-androideabi/release/deps --emit=dep-info,link --target arm-linux-androideabi -C ar=arm-linux-androideabi-ar -C linker=/home/sbar/git/servo/components/servo/./fake-ld.sh -L dependency=/home/sbar/git/servo/target/arm-linux-androideabi/release/deps -L dependency=/home/sbar/git/servo/target/arm-linux-androideabi/release/deps --extern heapsize_plugin=/home/sbar/git/servo/target/release/deps/libheapsize_plugin-00846447151e4ac3.so --extern serde_macros=/home/sbar/git/servo/target/release/deps/libserde_macros-c550fbd19e352e36.so --extern serde=/home/sbar/git/servo/target/arm-linux-androideabi/release/deps/libserde-3a777b14c091f0d1.rlib --extern heapsize=/home/sbar/git/servo/target/arm-linux-androideabi/release/deps/libheapsize-6b0058e51ea0ec07.rlib --extern matches=/home/sbar/git/servo/target/arm-linux-androideabi/release/deps/libmatches-030a774745cc4f96.rlib --extern encoding=/home/sbar/git/servo/target/arm-linux-androideabi/release/deps/libencoding-8b01435d6d00d080.rlib --cap-lints allow -C link-args=-fuse-ld=gold -C target-feature=+neon` (exit code: 1)

This issue doesn't reproduce with opt-level = 2

Also this issue doesn't reproduce when building for x86_64 (./mach build --verbose --release) with opt-level = 3

[alexcrichton]

I believe this was initially reported as servo/servo#10517 and @eddyb started diagnosis to conclude that the fix is upstream.

We should be able to just backport this to our current LLVM branch, although it'd be best if we could throw a test case along with it.

[sanxiyn]

LLVM backport merged in #33226.

[alexcrichton]

It seems the backport was merged and I believe this was fixed, so closing.