[all-commits] [llvm/llvm-project] 384383: [ARM] Common inverse constant predicates to VPNOT

[David Green via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 384383e15c177cd0dddae6b0999e527663fb3e22
      https://github.com/llvm/llvm-project/commit/384383e15c177cd0dddae6b0999e527663fb3e22
  Author: David Green <david.green at arm.com>
  Date:   2020-12-09 (Wed, 09 Dec 2020)

  Changed paths:
    M llvm/lib/Target/ARM/MVEVPTOptimisationsPass.cpp
    M llvm/test/CodeGen/Thumb2/mve-pred-constfold.ll
    M llvm/test/CodeGen/Thumb2/mve-vpt-optimisations.mir

  Log Message:
  -----------
  [ARM] Common inverse constant predicates to VPNOT

This scans through blocks looking for constants used as predicates in
MVE instructions. When two constants are found which are the inverse of
one another, the second can be replaced by a VPNOT of the first,
potentially allowing that not to be folded away into an else predicate
of a vpt block.

Differential Revision: https://reviews.llvm.org/D92470