[PATCH] D102739: [RISCV] Enable cross basic block aware vsetvli insertion

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.
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This patch extends D102737 <https://reviews.llvm.org/D102737> to allow VL/VTYPE changes to be taken
into account before adding an explicit vsetvli.

We do this by using a data flow analysis to propagate VL/VTYPE
information from predecessors until we've determined a value for
every value in the function.

We use this information combined with the requirements with each
block to determine if a vsetvli needs to be inserted before the
first vector instruction in the block.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D102739

Files:
  llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp
  llvm/test/CodeGen/RISCV/rvv/fixed-vectors-ctlz.ll
  llvm/test/CodeGen/RISCV/rvv/fixed-vectors-cttz.ll
  llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int.ll
  llvm/test/CodeGen/RISCV/rvv/fixed-vectors-select-fp.ll

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