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

[Luke Lau via llvm-commits]

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@@ -75,6 +75,8 @@ struct RISCVRegisterInfo : public RISCVGenRegisterInfo {
   // used during frame layout, and we may need to ensure that if we
   // split the offset internally that the DestReg is always aligned,
   // assuming that source reg was.
+  // If IsPrologueOrEpilogue is true, the function is called during prologue
+  // or epilogue generation.
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lukel97 wrote:

I think this comment can be removed

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