[all-commits] [llvm/llvm-project] fdef79: [RISCV] Fix assertion failure when zcmp extension ...

[garvit gupta via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: fdef7952cbc26fd31d0d92a4f14dde58bc461fe9
      https://github.com/llvm/llvm-project/commit/fdef7952cbc26fd31d0d92a4f14dde58bc461fe9
  Author: Garvit Gupta <quic_garvgupt at quicinc.com>
  Date:   2023-08-29 (Tue, 29 Aug 2023)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVFrameLowering.cpp
    A llvm/test/CodeGen/RISCV/zcmp-prolog-epilog-crash.mir

  Log Message:
  -----------
  [RISCV] Fix assertion failure when zcmp extension is enabled.

Before accessing "getOpcode" thorugh machine instruction, check if the iterator
has reached the end of Machine basic block otherwise we will crash at the
assertion `!NodePtr->isKnownSentinel()`.

The above assertion is hit in "Prologue/Epilogue Insertion & Frame Finalization
pass".

Reviewed By: craig.topper, wangpc

Differential Revision: https://reviews.llvm.org/D158256