[all-commits] [llvm/llvm-project] 42eba9: [AArch64][BFloat] basic AArch64 bfloat support

[Ties Stuij via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 42eba9b40b25cceeb3e6d432047c5ef99d4a7b50
      https://github.com/llvm/llvm-project/commit/42eba9b40b25cceeb3e6d432047c5ef99d4a7b50
  Author: Ties Stuij <ties.stuij at arm.com>
  Date:   2020-05-27 (Wed, 27 May 2020)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64CallingConvention.td
    M llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
    M llvm/lib/Target/AArch64/AArch64InstrFormats.td
    M llvm/lib/Target/AArch64/AArch64InstrInfo.td
    M llvm/lib/Target/AArch64/AArch64RegisterInfo.td

  Log Message:
  -----------
  [AArch64][BFloat] basic AArch64 bfloat support

Summary:
This patch adds the bfloat type to the AArch64 backend:
- adds it as part of the FPR16 register class
- adds bfloat calling conventions
- as f16 is now not the only FPR16 type anymore, we need to constrain a number
  of instruction patterns using FPR16Op to help out the TableGen type inferrer

This patch is part of a series implementing the Bfloat16 extension of the
Armv8.6-a architecture, as detailed here:

https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/arm-architecture-developments-armv8-6-a

The bfloat type, and its properties are specified in the Arm Architecture
Reference Manual:

https://developer.arm.com/docs/ddi0487/latest/arm-architecture-reference-manual-armv8-for-armv8-a-architecture-profile

Reviewers: t.p.northover, c-rhodes, fpetrogalli, sdesmalen, ostannard, LukeGeeson, ab

Reviewed By: fpetrogalli

Subscribers: pbarrio, LukeGeeson, kristof.beyls, hiraditya, danielkiss, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79709