Jan Philipp Hafer 0550198c98 compiler_rt: simplify popcount "magic constants"
- magic constants are nicer to construct ie with
  (~@as(unsigned type, 0) / 3) == 0x55...55
- thanks to Stefan Kanthak for the idea
2021-12-14 14:19:51 -08:00
..
2019-09-25 23:35:41 -04:00

This compiler-rt library is ported from LLVM.

It's needed because LLVM emits library calls to compiler-rt when hardware lacks functionality, for example, 64-bit integer multiplication on 32-bit x86.

This library is automatically built as-needed for the compilation target and then statically linked and therefore is a transparent dependency for the programmer.

Any bugs should be solved by trying to duplicate the bug upstream.

  • If the bug exists upstream, get it fixed with the LLVM team and then port the fix downstream to Zig.
  • If the bug only exists in Zig, something went wrong porting the code, and you can run the C code and Zig code side by side in a debugger to figure out what's happening differently.