[Bug]: error: ran out of registers during register allocation with -fsanitize=address and -target armv7-unknown-linux

[appujee]

The code is pretty big as I haven't spent enough time reducing it. But the repro test case can be found here:

https://godbolt.org/z/WafcG8G95

$ clang++ -std=c++20 -target armv7-unknown-linux -fsanitize=address -mllvm -asan-use-stack-safety=0

[appujee]

Related discussion in android/ndk#2030

[llvmbot]

@llvm/issue-subscribers-backend-arm

Author: None (appujee)

The code is pretty big as I haven't spent enough time reducing it. But the repro test case can be found here:

https://godbolt.org/z/WafcG8G95

$ clang++ -std=c++20 -target armv7-unknown-linux -fsanitize=address -mllvm -asan-use-stack-safety=0

[ostannard]

Reduced down to this, which gives the same error with -asan-use-stack-safety=0 and -asan-use-stack-safety=1:

template <class b> b *addressof(b &);

void bc() {
  _Atomic(long long) bd;
  __c11_atomic_store(addressof(bd), 0, 0);
}

void m_fn2(long long p1) { bc(); }

$ /work/llvm/build/bin/clang  -std=c++20 -target armv7-unknown-linux -fsanitize=address -c out-of-regs.cpp
clang: warning: unknown platform, assuming -mfloat-abi=soft
clang: warning: unknown platform, assuming -mfloat-abi=soft
clang: warning: unknown platform, assuming -mfloat-abi=soft
error: ran out of registers during register allocation
1 error generated.