[all-commits] [llvm/llvm-project] de2b70: [RISCV] Lower CONCAT_VECTORS to INSERT_SUBVECTOR n...

[Fraser Cormack via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: de2b70010aed514acfb919f0ad997ae785fedfe0
      https://github.com/llvm/llvm-project/commit/de2b70010aed514acfb919f0ad997ae785fedfe0
  Author: Fraser Cormack <fraser at codeplay.com>
  Date:   2021-03-02 (Tue, 02 Mar 2021)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVISelLowering.cpp
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-fp2i.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-exttrunc.ll

  Log Message:
  -----------
  [RISCV] Lower CONCAT_VECTORS to INSERT_SUBVECTOR nodes

The default expansion of CONCAT_VECTORS goes through the stack. This
patch avoids that penalty by custom-lowering CONCAT_VECTORS to a series
of INSERT_SUBVECTOR nodes. Futher optimizations are possible, but this
is a good start.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D97692