precompiling gave `AssertionError: fieldoffset(CheckPadAfter64, 3) == CACHELINE_SIZE`

[anandijain]

(ConcurrentCollections) pkg> st
     Project ConcurrentCollections v0.1.0
      Status `~/.julia/dev/ConcurrentCollections.jl/Project.toml` (empty project)

julia> versioninfo()
Julia Version 1.7.0-rc1
Commit 9eade6195e (2021-09-12 06:45 UTC)
Platform Info:
  OS: macOS (arm64-apple-darwin20.5.0)
  CPU: Apple M1
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, cyclone)
Environment:
  JULIA_NUM_THREADS = 4
  JULIA_EDITOR = code

maybe you're already aware of this. thanks for the package btw

[tkf]

Thanks for the report! I don't have a macOS and so I didn't know this :)

[tkf]

Hmm... it worked on github action: https://github.com/tkf/ConcurrentCollections.jl/pull/36/checks?check_run_id=3659030733#step:3:31

Julia Version 1.8.0-DEV.563
Commit 4f3a89e3ab (2021-09-20 19:34 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin19.6.0)
  CPU: Intel(R) Xeon(R) CPU E5-1650 v2 @ 3.50GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, ivybridge)

Do you mind checking this in your REPL?

julia> primitive type PadAfter64 448 end

julia> mutable struct CheckPadAfter64
           a::UInt64
           pad::PadAfter64
           b::UInt64
       end

julia> fieldoffset(CheckPadAfter64, 3)
0x0000000000000040

[anandijain]

yeah notice that the action is using x86 darwin not arm.

julia> primitive type PadAfter64 448 end

julia> mutable struct CheckPadAfter64
           a::UInt64
           pad::PadAfter64
           b::UInt64
       end

julia> fieldoffset(CheckPadAfter64, 3)
0x0000000000000050

[tkf]

Ah, I see. Does ARM use a different alignment rule?

[anandijain]

not sure, but ive run into a bunch of other issues using m1 so i figured it was related

[tkf]

OK, thanks. Need more digging...

Edit: clang seems to use 64 for both x84_64 and armv8 https://godbolt.org/z/PorhGc1sf