[all-commits] [llvm/llvm-project] add205: Reland "[llvm-exegesis] Fix preservation of RDI in...

[Aiden Grossman via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: add20537cc764b8afb97df85acba7c21d6537ae3
      https://github.com/llvm/llvm-project/commit/add20537cc764b8afb97df85acba7c21d6537ae3
  Author: Aiden Grossman <agrossman154 at yahoo.com>
  Date:   2023-11-16 (Thu, 16 Nov 2023)

  Changed paths:
    A llvm/test/tools/llvm-exegesis/X86/latency/subprocess-preserved-registers.s
    M llvm/tools/llvm-exegesis/lib/X86/Target.cpp

  Log Message:
  -----------
  Reland "[llvm-exegesis] Fix preservation of RDI in subprocess mode (#72458)"

This reverts commit 186db1bcb0096a6af348d7e17866c68fa2004068.

This relands commit 0718c1a8405ac130d72cd3525befed2911618cc7.

The REQUIRES flag in the test that was added only specified that the
machine needed to have the capability to execute the snippet rather than
actually run it with performance counters. This would work with
--dummy-perf-counters, but that is not currently supported in the
subprocess execution mode. So for now, we require the ability to
actually perform measurements to prevent test failures in configurations
that don't have libpfm or access to performance counters.