Revert: r343521 and r343541: [globalisel] Add a combiner helpers for extending loads and use them in a pre-legalize combiner for AArch64

There's a strange assertion on two of the Green Dragon bots that goes away when
this is reverted. The assertion is in RegBankAlloc and if it is this commit then
-verify-machine-instrs should have caught it earlier in the pipeline.

llvm-svn: 343546

1 files changed, 1 insertions, 30 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/Combiner.cpp b/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
index f3f075af486..0bc5b87de15 100644
--- a/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
@@ -25,34 +25,6 @@
 
 using namespace llvm;
 
-namespace {
-/// This class acts as the glue the joins the CombinerHelper to the overall
-/// Combine algorithm. The CombinerHelper is intended to report the
-/// modifications it makes to the MIR to the CombinerChangeObserver and the
-/// observer subclass will act on these events. In this case, instruction
-/// erasure will cancel any future visits to the erased instruction and
-/// instruction creation will schedule that instruction for a future visit.
-/// Other Combiner implementations may require more complex behaviour from
-/// their CombinerChangeObserver subclass.
-class WorkListMaintainer : public CombinerChangeObserver {
-  using WorkListTy = GISelWorkList<512>;
-  WorkListTy &WorkList;
-
-public:
-  WorkListMaintainer(WorkListTy &WorkList) : WorkList(WorkList) {}
-  virtual ~WorkListMaintainer() {}
-
-  void erasedInstr(MachineInstr &MI) override {
-    LLVM_DEBUG(dbgs() << "Erased: "; MI.print(dbgs()); dbgs() << "\n");
-    WorkList.remove(&MI);
-  }
-  void createdInstr(MachineInstr &MI) override {
-    LLVM_DEBUG(dbgs() << "Created: "; MI.print(dbgs()); dbgs() << "\n");
-    WorkList.insert(&MI);
-  }
-};
-}
-
 Combiner::Combiner(CombinerInfo &Info, const TargetPassConfig *TPC)
     : CInfo(Info), TPC(TPC) {
   (void)this->TPC; // FIXME: Remove when used.
@@ -81,7 +53,6 @@ bool Combiner::combineMachineInstrs(MachineFunction &MF) {
     // down RPOT.
     Changed = false;
     GISelWorkList<512> WorkList;
-    WorkListMaintainer Observer(WorkList);
     for (MachineBasicBlock *MBB : post_order(&MF)) {
       if (MBB->empty())
         continue;
@@ -101,7 +72,7 @@ bool Combiner::combineMachineInstrs(MachineFunction &MF) {
     while (!WorkList.empty()) {
       MachineInstr *CurrInst = WorkList.pop_back_val();
       LLVM_DEBUG(dbgs() << "Try combining " << *CurrInst << "\n";);
-      Changed |= CInfo.combine(Observer, *CurrInst, Builder);
+      Changed |= CInfo.combine(*CurrInst, Builder);
     }
     MFChanged |= Changed;
   } while (Changed);