[ARM][MVE] VPT Blocks: findVCMPToFoldIntoVPS

This is a recommit of D71330, but with a few things fixed and changed:

1) ReachingDefAnalysis: this was not running with optnone as it was checking
skipFunction(), which other analysis passes don't do. I guess this is a
copy-paste from a codegen pass.
2) VPTBlockPass: here I've added skipFunction(), because like most/all
optimisations, we don't want to run this with optnone.

This fixes the issues with the initial/previous commit: the VPTBlockPass was
running with optnone, but ReachingDefAnalysis wasn't, and so VPTBlockPass was
crashing querying ReachingDefAnalysis.

I've added test case mve-vpt-block-optnone.mir to check that we don't run
VPTBlock with optnone.

Differential Revision: https://reviews.llvm.org/D71470

1 files changed, 0 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/ReachingDefAnalysis.cpp b/llvm/lib/CodeGen/ReachingDefAnalysis.cpp
index 61ae3b75ab5..3c1f9905afd 100644
--- a/llvm/lib/CodeGen/ReachingDefAnalysis.cpp
+++ b/llvm/lib/CodeGen/ReachingDefAnalysis.cpp
@@ -133,8 +133,6 @@ void ReachingDefAnalysis::processBasicBlock(
 }
 
 bool ReachingDefAnalysis::runOnMachineFunction(MachineFunction &mf) {
-  if (skipFunction(mf.getFunction()))
-    return false;
   MF = &mf;
   TRI = MF->getSubtarget().getRegisterInfo();