[all-commits] [llvm/llvm-project] 52b5f1: [RISCV] Extend dataflow workaround from D119518 to...

[Philip Reames via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 52b5f1f7d41097e8059fac97f3c91dd4012d3df3
      https://github.com/llvm/llvm-project/commit/52b5f1f7d41097e8059fac97f3c91dd4012d3df3
  Author: Philip Reames <preames at rivosinc.com>
  Date:   2022-05-12 (Thu, 12 May 2022)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
    M llvm/test/CodeGen/RISCV/rvv/vsetvli-insert-crossbb.mir

  Log Message:
  -----------
  [RISCV] Extend dataflow workaround from D119518 to fallthrough blocks

We've got a lurking problem with our data flow implementation where different phases disagree, resulting in possible miscompiles. D119518 introduced a workaround, but failed to consider blocks without terminators (e.g. fallthroughs).

I have a deeper rework of the algorithm in flight over in D125232, but this patch is specifically a minimal fix for an active miscompile. That change can be reworked over this once landed.

Differential Revision: https://reviews.llvm.org/D125408