LLD hangs forever on AArch64

[kongy]

LLD hangs forever when building AArch64 libpdfclient.so on Android. Bisection points to commit 8bc9551.

Reproducer is: https://drive.google.com/file/d/13JaN0fdJNWd1ozzmVhySA1vFVKy1T3ut/view?usp=sharing

[llvmbot]

@llvm/issue-subscribers-backend-aarch64

Author: Yi Kong (kongy)

LLD hangs forever when building AArch64 libpdfclient.so on Android. Bisection points to commit 8bc9551.

Reproducer is: https://drive.google.com/file/d/13JaN0fdJNWd1ozzmVhySA1vFVKy1T3ut/view?usp=sharing

[davemgreen]

Do you happen to have a smaller example that doesn't require LTO?

[kongy]

I tried to build AOSP with LTO off. Unfortunately, it did not hit the same issue.

[davemgreen]

OK - This gets stuck, I haven't tried to reduce it further yet.
https://godbolt.org/z/M9cKKMWeb

The same thing happens when running it through -codegenprepare, I think because it is sinking and (load ..), 0x255 and then re-hoisting the and back to the load. We can hopefully add a fix to prevent that from happening.