[llvm] [LLVM] Add HasFakeUses to MachineFunction (PR #110097)

[Matt Arsenault via llvm-commits]

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@@ -477,7 +477,7 @@ bool MachineScheduler::runOnMachineFunction(MachineFunction &mf) {
 }
 
 bool PostMachineScheduler::runOnMachineFunction(MachineFunction &mf) {
-  if (skipFunction(mf.getFunction()))
+  if (mf.hasFakeUses() || skipFunction(mf.getFunction()))
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arsenm wrote:

Although actually this looks like another existing bug with optnone. in AMDGPU we add a dedicated pass to recognize hazards at -O0 to replace the postRA scheduler hazard handling. That won't happen for higher opt levels for an optnone function 

https://github.com/llvm/llvm-project/pull/110097