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

[Matt Arsenault via llvm-commits]

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@@ -653,7 +678,8 @@ void RegBankLegalizeHelper::applyMappingPHI(MachineInstr &MI) {
   // We accept all types that can fit in some register class.
   // Uniform G_PHIs have all sgpr registers.
   // Divergent G_PHIs have vgpr dst but inputs can be sgpr or vgpr.
-  if (Ty == LLT::scalar(32) || Ty == LLT::pointer(4, 64)) {
+  if (Ty == LLT::scalar(32) || Ty == LLT::pointer(1, 64) ||
+      Ty == LLT::pointer(4, 64)) {
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arsenm wrote:

Why does this need to maintain a list of types 

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