[llvm] AMDGPU/GlobalISel: Disable LCSSA pass (PR #124297)

[Matt Arsenault via llvm-commits]

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@@ -312,6 +312,12 @@ bool AMDGPURegBankLegalize::runOnMachineFunction(MachineFunction &MF) {
     }
 
     // Opcodes that also support S1.
+    if (Opc == G_FREEZE &&
+        MRI.getType(MI->getOperand(0).getReg()) != LLT::scalar(1)) {
+      RBLHelper.applyMappingTrivial(*MI);
+      continue;
+    }
+
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arsenm wrote:

Unrelated to LCSSA change 

https://github.com/llvm/llvm-project/pull/124297