[all-commits] [llvm/llvm-project] 340054: [AArch64][SME] Remove combination of private-ZA an...

[Sander de Smalen via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 340054e561bc7fa407de5c591d503ad52fbffaff
      https://github.com/llvm/llvm-project/commit/340054e561bc7fa407de5c591d503ad52fbffaff
  Author: Sander de Smalen <sander.desmalen at arm.com>
  Date:   2024-01-19 (Fri, 19 Jan 2024)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    M llvm/test/CodeGen/AArch64/sme-lazy-save-call-remarks.ll
    M llvm/test/CodeGen/AArch64/sme-lazy-save-call.ll

  Log Message:
  -----------
  [AArch64][SME] Remove combination of private-ZA and preserves_za. (#78563)

The new Clang attributes no longer support the combination of having a
private-ZA function that preserves ZA. The use of __arm_preserves("za")
means that ZA is shared and preserved.

There wasn't that much benefit to the special handling of this, because
in practice it only meant that we'd avoid restoring the lazy-save
afterwards, but it still needed setting up a lazy-save (with the
possibility of using a 0-sized buffer).

Perhaps a new attribute will be added in the future to support this
case, at which point we can revert back some of the changes removed in
this patch. But for now removing this code simplifies things.