[all-commits] [llvm/llvm-project] feff66: [RISCV] Further optimize BUILD_VECTORs with repeat...

[Fraser Cormack via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: feff66a0823144dd2c4a26e6008645786531356c
      https://github.com/llvm/llvm-project/commit/feff66a0823144dd2c4a26e6008645786531356c
  Author: Fraser Cormack <fraser at codeplay.com>
  Date:   2021-03-23 (Tue, 23 Mar 2021)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVISelLowering.cpp
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-bitreverse.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-ctpop.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-fp-buildvec.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int-splat.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-int.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-masked-gather.ll
    M llvm/test/CodeGen/RISCV/rvv/fixed-vectors-masked-scatter.ll
    M llvm/test/CodeGen/RISCV/srem-seteq-illegal-types.ll

  Log Message:
  -----------
  [RISCV] Further optimize BUILD_VECTORs with repeated elements

This patch builds upon the initial BUILD_VECTOR work introduced in
D98700. It further optimizes the lowering of BUILD_VECTOR by using
VSELECT operations to effectively insert repeated elements into the
vector with relatively few instructions. This allows us to optimize more
BUILD_VECTORs without significantly increasing the size of the generated
code.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D98969