[all-commits] [llvm/llvm-project] a86bbe: [AArch64][GlobalISel] Handle any-extending FPR loa...

[Amara Emerson via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a86bbe1e3191800d42abf073a060eb8601b8be37
      https://github.com/llvm/llvm-project/commit/a86bbe1e3191800d42abf073a060eb8601b8be37
  Author: Amara Emerson <amara at apple.com>
  Date:   2021-09-01 (Wed, 01 Sep 2021)

  Changed paths:
    M llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
    M llvm/test/CodeGen/AArch64/GlobalISel/select-load.mir

  Log Message:
  -----------
  [AArch64][GlobalISel] Handle any-extending FPR loads in manual selection code.

When we have an any-extending FPR bank load, none of the tablegen patterns
match and we fall back to the C++ selector. Like with the truncating stores
that were fixed recently, the C++ wasn't able to handle it and ended up
generating invalid copies between different size regclasses.

This change adds handling for this case, splitting the load into a regular
load and a SUBREG_TO_REG to extend it into the original wide destination reg.