[Power] Segmentation fault in vecelement test

[vchuravy]

Test failure in vecelement tests, reduced to:

using Test

struct Herd{N,T}
    elts::NTuple{N,Base.VecElement{T}}
    Herd{N,T}(elts::NTuple{N,T}) where {N,T} = new(ntuple(i->Base.VecElement{T}(elts[i]), N))
end

function check(x::Herd{N,T}) where {N,T}
    for i=1:N
        @test x.elts[i].value === N*N+i-1
    end
end
check(Herd{4,Int}((16,17,18,19)))

Which in turn has wonderful heisenbug behaviour. The closer you are to observing it the rarer it gets.

[vchuravy]

Reduced to:

struct Herd{N,T}
    elts::NTuple{N,Base.VecElement{T}}
    Herd{N,T}(elts::NTuple{N,T}) where {N,T} = new(ntuple(i->Base.VecElement{T}(elts[i]), N))
end

@noinline function check(x::Herd{N,T}) where {N,T}
    cond = true
    for i=1:N
      try
        cond |= x.elts[i].value === N*N+i-1
      catch
      end
    end
    cond
end

f() = check(Herd{4, Int}((16,17,18,19)))

[vchuravy]

Reduced to a standalone reproducer https://gist.github.com/vchuravy/b95aca54a4bdb6a1d386e5c5d5c27bc0

[vchuravy@service0001 julia]$ usr/tools/lli check.ll                                                                                                                                                                                 
[vchuravy@service0001 julia]$ usr/tools/lli check.ll
[vchuravy@service0001 julia]$ usr/tools/lli check.ll
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace.
Stack dump:
0.      Program arguments: usr/tools/lli check.ll 

[vchuravy]

Ok seems to be caused by https://reviews.llvm.org/D92906