Incorrect result in accumulator expression

Something is causing this third case to be unhappy:

julia> using LoopVectorization

julia> let a = 1.0, b = 1.0, h = 1.0, v = rand(10)
           @avx for i in eachindex(v)
               h = a * v[i] + h
           end
       end
5.877242734755752

julia> let a = 1.0, b = 1.0, h = 1.0, v = rand(10)
           @avx for i in eachindex(v)
               h = v[i] + b * h
           end
       end
5.35890841491465

julia> let a = 1.0, b = 1.0, h = 1.0, v = rand(10)
           @avx for i in eachindex(v)
               h = a * v[i] + b * h
           end
       end
ERROR: UndefVarError: ##op#602_0 not defined
Stacktrace:
 [1] macro expansion at /home/mason/.julia/packages/LoopVectorization/OZUlx/src/reconstruct_loopset.jl:503 [inlined]
 [2] _avx_! at /home/mason/.julia/packages/LoopVectorization/OZUlx/src/reconstruct_loopset.jl:503 [inlined]
 [3] top-level scope at ./REPL[16]:2

Furthermore, if I try to fix it by changing around the syntax, it actually runs and gets an incorrect result:

julia> let a = 1.5, b = 2.0, h = 3.0, v = rand(10)
           @avx for i in eachindex(v)
               h_old = h
               h = a * v[i] + b * h_old
           end
           h
       end
3.0

julia> let a = 1.5, b = 2.0, h = 3.0, v = rand(10)
           for i in eachindex(v)
               h_old = h
               h = a * v[i] + b * h_old
           end
           h
       end
3979.1681593580383

(@v1.5) pkg> st LoopVectorization
Status `~/.julia/environments/v1.5/Project.toml`
  [bdcacae8] LoopVectorization v0.8.24

julia> versioninfo()
Julia Version 1.5.0
Commit 96786e22cc* (2020-08-01 23:44 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: AMD Ryzen 5 2600 Six-Core Processor
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-9.0.1 (ORCJIT, znver1)
Environment:
  JULIA_NUM_THREADS = 6

Reproduisez les trois exemples d’accumulateurs avec Julia 1.5 et LoopVectorization v0.8.24. Commencez à src/reconstruct_loopset.jl:503, identifié dans la stack trace, et suivez la manière dont la boucle @avx traite l’expression combinée a * v[i] + b * h. Le travail est terminé lorsque l’expression ne déclenche plus UndefVarError et que la boucle transformée produit le même résultat que la boucle ordinaire.