Suggestions for getting crc32c library working with CMAKE_OSX_ARCHITECTURES

Usage
1

Google’s crc32c library is pretty small and gives good performing crc32c implementations for arm and intel https://github.com/google/crc32c

It currently builds for Intel (everywhere) and arm on linux. My PR here gets it working for ARM on macOS https://github.com/google/crc32c/pull/43.

However it doesn’t work when using CMAKE_OSX_ARCHITECTURES=“arm64;x86_64” for a few reasons:

  • try_compile of the intel or arm intrinsics fails when compiling the other platform so they return false
  • if forced to true the arm compiler complains at being sent -msse4.2 for the intel file and the intel compile complains about the equivalent arm thing.

Does anyone have any good ideas of how to make a library like this work well?

2

Hmm. I’m not sure how to send arch-specific flags to a macOS fat binary compilation.

Cc: @brad.king @gjasny

3

You could use -Xarch_xyz like: -Xarch_i386 -fomit-frame-pointer. The best documentation I could find is here: DriverInternals.

Hope this helps!

1 Like
4

Ah. Note that in actual usage, you’ll likely need to let CMake know that these are compound options like "SHELL:-Xarch_i386 -fomit-frame-pointer".