[llvm] [RISCV] Use vsetvli instead of vlenb in Prologue/Epilogue (PR #113756)

[Philip Reames via llvm-commits]

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@@ -6049,6 +6049,11 @@ let hasSideEffects = 0, mayLoad = 0, mayStore = 0, isCodeGenOnly = 1 in {
                                [(set GPR:$rd, (riscv_read_vlenb))]>,
                         PseudoInstExpansion<(CSRRS GPR:$rd, SysRegVLENB.Encoding, X0)>,
                         Sched<[WriteRdVLENB]>;
+  let Defs = [VL, VTYPE] in {
+  def PseudoReadMulVLENB : Pseudo<(outs GPR:$rd), (ins uimm5:$shamt),
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preames wrote:

Naming wise, this doesn't seem supper clear.  Possible PseudoReadVLENBViaVSETVLIX0?

https://github.com/llvm/llvm-project/pull/113756