Jenkins asan+ubsan build failure / X86TargetLowering::LowerBUILD_VECTOR

[Matthias Braun via llvm-commits]

Hi,

the greendragon asan+ubsan build started failing:

http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_check/782/

I believe this was triggered by r253952 "[X86][SSE] Detect AVG pattern during instruction combine for SSE2/AVX2/AVX512BW."

Looking at the failure this seems to be an cause by an existing bug in X86TargetLowering::LowerBUILD_VECTOR() which uses an unsigned variable as a bitset with a bit for each vector element. The test added contains some "64 x XXX" vector types and overflows this.

- Matthias