[PATCH] D125703: [RISCV] Fix missing vsetvli in transparent block case

[Philip Reames via Phabricator via llvm-commits]

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We've got a lurking problem with our data flow implementation where different phases disagree, resulting in possible miscompiles. D119518 <https://reviews.llvm.org/D119518> introduced a workaround, but failed to consider blocks which only contain load/stores compatible with their incoming state.

When I went to rebase and simplify D125232 <https://reviews.llvm.org/D125232>, it turned out that not all of the correctness issues had been fixed yet after all.  This is the correctness fix accidentally embedded in the original more complicated version.

Note that the test changes here are mostly regressions.  It's worth noting that the simplified version of D125232 <https://reviews.llvm.org/D125232> exactly reverses all the non-functional diffs in the test caused here.  I expect to land them both close in time.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D125703

Files:
  llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
  llvm/test/CodeGen/RISCV/rvv/vsetvli-insert-crossbb.ll
  llvm/test/CodeGen/RISCV/rvv/vsetvli-insert-crossbb.mir

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