[all-commits] [llvm/llvm-project] d7b77f: [ARM] Add qadd lowering from a sadd_sat

[David Green via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: d7b77f2203dd09e8d6ab30128cc8b8ae7313c0ee
      https://github.com/llvm/llvm-project/commit/d7b77f2203dd09e8d6ab30128cc8b8ae7313c0ee
  Author: David Green <david.green at arm.com>
  Date:   2019-10-21 (Mon, 21 Oct 2019)

  Changed paths:
    M llvm/lib/Target/ARM/ARMISelLowering.cpp
    M llvm/lib/Target/ARM/ARMInstrInfo.td
    M llvm/lib/Target/ARM/ARMInstrThumb2.td
    M llvm/lib/Target/ARM/ARMSubtarget.h
    M llvm/test/CodeGen/ARM/qdadd.ll
    M llvm/test/CodeGen/ARM/sadd_sat.ll
    M llvm/test/CodeGen/ARM/sadd_sat_plus.ll
    M llvm/test/CodeGen/ARM/ssub_sat.ll
    M llvm/test/CodeGen/ARM/ssub_sat_plus.ll

  Log Message:
  -----------
  [ARM] Add qadd lowering from a sadd_sat

This lowers a sadd_sat to a qadd by treating it as legal. Also adds qsub at the
same time.

The qadd instruction sets the q flag, but we already have many cases where we
do not model this in llvm.

Differential Revision: https://reviews.llvm.org/D68976

llvm-svn: 375411