[llvm] [AMDGPU] Add support for GFX12 expert scheduling mode 2 (PR #170319)

[Stephen Thomas via llvm-commits]

================
@@ -2741,7 +2979,14 @@ bool SIInsertWaitcnts::run(MachineFunction &MF) {
   AMDGPU::IsaVersion IV = AMDGPU::getIsaVersion(ST->getCPU());
 
   if (ST->hasExtendedWaitCounts()) {
-    MaxCounter = NUM_EXTENDED_INST_CNTS;
+    if (ST->hasSoftwareHazardMode() &&
+        (MF.getFunction()
+             .getFnAttribute("amdgpu-software-hazard-mode")
----------------
stepthomas wrote:

This definitely feels like something that would end up being needed at some point anyway.

https://github.com/llvm/llvm-project/pull/170319