[all-commits] [llvm/llvm-project] 568678: [BPF] Fix BitCast Assertion with NonZero AddrSpace...

[yonghong-song via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5686786c550c6da6d1169b9bffc31cece1161902
      https://github.com/llvm/llvm-project/commit/5686786c550c6da6d1169b9bffc31cece1161902
  Author: yonghong-song <yhs at fb.com>
  Date:   2025-03-11 (Tue, 11 Mar 2025)

  Changed paths:
    M llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp
    A llvm/test/CodeGen/BPF/CORE/arena_bitcast.ll

  Log Message:
  -----------
  [BPF] Fix BitCast Assertion with NonZero AddrSpace (#130722)

Alexei reported a bpf selftest failure with recent llvm for bpf prog
file progs/arena_spin_lock.c. The failure only happens when clang is
built with cmake option LLVM_ENABLE_ASSERTIONS=ON.

The error message looks like:
```
 clang: /home/yhs/work/yhs/llvm-project/llvm/lib/IR/Instructions.cpp:3460:
   llvm::BitCastInst::BitCastInst(Value *, Type *, const Twine &, InsertPosition):
   Assertion `castIsValid(getOpcode(), S, Ty) && "Illegal BitCast"' failed.
```
Further investigation shows that the problem is triggered in
  BPF/BPFAbstractMemberAccess.cpp
for code
```
  auto *BCInst =
      new BitCastInst(Base, PointerType::getUnqual(BB->getContext()));
```
For the above BitCastInst, Since 'Base' has non-zero AddrSapce, the
compiler expects the type also has the same AddrSpace. But the above
PointerType::getUnqual(...) does not have AddrSpace and hence causes the
assertion failure.

Providing the proper AddrSpace for the BitCast type fixed the issue.

Co-authored-by: Yonghong Song <yonghong.song at linux.dev>



To unsubscribe from these emails, change your notification settings at https://github.com/llvm/llvm-project/settings/notifications