[all-commits] [llvm/llvm-project] f302e0: [AArch64] Exclude optional features from HasV8_0rOps.

[Simon Tatham via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f302e0b5dd402e629620a58f9115a3441c65d60f
      https://github.com/llvm/llvm-project/commit/f302e0b5dd402e629620a58f9115a3441c65d60f
  Author: Simon Tatham <simon.tatham at arm.com>
  Date:   2022-01-25 (Tue, 25 Jan 2022)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64.td
    M llvm/test/MC/AArch64/armv8.2a-crypto.s
    M llvm/test/MC/Disassembler/AArch64/armv8.3a-complex.txt
    M llvm/test/MC/Disassembler/AArch64/armv8.5a-predres.txt
    M llvm/test/MC/Disassembler/AArch64/armv8.5a-specrestrict.txt
    M llvm/test/MC/Disassembler/AArch64/armv8.5a-ssbs.txt
    M llvm/test/MC/Disassembler/AArch64/armv8a-fpmul.txt

  Log Message:
  -----------
  [AArch64] Exclude optional features from HasV8_0rOps.

The following SubtargetFeatures are removed from the definition of
HasV8_0rOps, on the grounds that they are optional in Armv8.4-A, and
therefore (by the definition of Armv8.0-R) also optional in v8.0-R:

 * performance monitoring: FeaturePerfMon
 * cryptography: FeatureSM4 and FeatureSHA3
 * half-precision FP: FeatureFullFP16, FeatureFP16FML
 * speculation control: FeatureSSBS, FeaturePredRes, FeatureSB,
   FeatureSpecRestrict

This isn't the full set of features that are listed as optional in the
spec. FeatureCCIDX and FeatureTRACEV8_4 are also optional. But LLVM
includes those in HasV8_3aOps and HasV8_4aOps respectively (I think on
the grounds that the system registers they enable are useful to be
able to access after a runtime check), and so for consistency, I've
left those in HasV8_0rOps too.

After this commit, HasV8_0rOps is a strict subset of HasV8_4aOps (but
missing features that are not in Armv8.0-R at all).

The definition of Cortex-R82 is correspondingly updated to add most of
the features that I've removed from base Armv8.0-R (with the exception
of the cryptography ones), since that particular implementation of
v8.0-R does have them.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D118045