[llvm] remove redundant checks for invalidate instructions (PR #166139)

[Juan Manuel Martinez Caamaño via llvm-commits]

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@@ -527,19 +527,24 @@ class SIInsertWaitcnts {
 #endif // NDEBUG
   }
 
-  // Return the appropriate VMEM_*_ACCESS type for Inst, which must be a VMEM
-  // instruction.
-  WaitEventType getVmemWaitEventType(const MachineInstr &Inst) const {
+  // Return an optional WaitEventType value if Inst is a cache
+  // invalidate or WB instruction.
+  std::optional<WaitEventType>
+  getInvOrWBWaitEventType(const MachineInstr &Inst) const {
     switch (Inst.getOpcode()) {
     case AMDGPU::GLOBAL_INV:
       return VMEM_READ_ACCESS; // tracked using loadcnt
     case AMDGPU::GLOBAL_WB:
     case AMDGPU::GLOBAL_WBINV:
       return VMEM_WRITE_ACCESS; // tracked using storecnt
     default:
-      break;
+      return {};
     }
+  }
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jmmartinez wrote:

You could move this into a static helper outside of the class now. It's not accessing any class members.

https://github.com/llvm/llvm-project/pull/166139