[llvm] [RISCV] Split out VSETVLIInfo AVL states to be more explicit (PR #89964)

[Piyou Chen via llvm-commits]

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@@ -935,14 +964,13 @@ static VSETVLIInfo computeInfoForInstr(const MachineInstr &MI, uint64_t TSFlags,
   // AVL operand with the AVL of the defining vsetvli.  We avoid general
   // register AVLs to avoid extending live ranges without being sure we can
   // kill the original source reg entirely.
-  if (InstrInfo.hasAVLReg() && InstrInfo.getAVLReg().isVirtual()) {
-    MachineInstr *DefMI = MRI->getVRegDef(InstrInfo.getAVLReg());
-    if (DefMI && isVectorConfigInstr(*DefMI)) {
+  if (InstrInfo.hasAVLReg()) {
+    MachineInstr *DefMI = MRI->getUniqueVRegDef(InstrInfo.getAVLReg());
+    if (isVectorConfigInstr(*DefMI)) {
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BeMg wrote:

getUniqueVRegDef may return a nullptr if none is found, although a valid program should always have a VRegDef here.

https://github.com/llvm/llvm-project/pull/89964