[all-commits] [llvm/llvm-project] 020746: [XCore] Set MaxAtomicSizeInBitsSupported to 0 (#74...

[James Y Knight via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 020746d1b1d0686498b7faa8b63920f61817d93a
      https://github.com/llvm/llvm-project/commit/020746d1b1d0686498b7faa8b63920f61817d93a
  Author: James Y Knight <jyknight at google.com>
  Date:   2023-12-05 (Tue, 05 Dec 2023)

  Changed paths:
    M llvm/lib/Target/XCore/XCoreISelLowering.cpp
    M llvm/lib/Target/XCore/XCoreISelLowering.h
    M llvm/test/CodeGen/XCore/atomic.ll

  Log Message:
  -----------
  [XCore] Set MaxAtomicSizeInBitsSupported to 0 (#74389)

XCore does not appear to have any support for atomicrmw or cmpxchg.

This will result in all atomic operations getting expanded to __atomic_*
libcalls via AtomicExpandPass, which matches what Clang already does in
the frontend.

Additionally, remove the code which handles atomic load/store, as it
will no longer be used.