1 files changed, 81 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/GlobalISel/Combiner.cpp b/contrib/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
new file mode 100644
index 000000000000..0bc5b87de150
--- /dev/null
+++ b/contrib/llvm/lib/CodeGen/GlobalISel/Combiner.cpp
@@ -0,0 +1,81 @@
+//===-- lib/CodeGen/GlobalISel/GICombiner.cpp -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file constains common code to combine machine functions at generic
+// level.
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/GlobalISel/Combiner.h"
+#include "llvm/CodeGen/GlobalISel/CombinerInfo.h"
+#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
+#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
+#include "llvm/CodeGen/GlobalISel/GISelWorkList.h"
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/CodeGen/GlobalISel/Utils.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Support/Debug.h"
+
+#define DEBUG_TYPE "gi-combiner"
+
+using namespace llvm;
+
+Combiner::Combiner(CombinerInfo &Info, const TargetPassConfig *TPC)
+    : CInfo(Info), TPC(TPC) {
+  (void)this->TPC; // FIXME: Remove when used.
+}
+
+bool Combiner::combineMachineInstrs(MachineFunction &MF) {
+  // If the ISel pipeline failed, do not bother running this pass.
+  // FIXME: Should this be here or in individual combiner passes.
+  if (MF.getProperties().hasProperty(
+          MachineFunctionProperties::Property::FailedISel))
+    return false;
+
+  MRI = &MF.getRegInfo();
+  Builder.setMF(MF);
+
+  LLVM_DEBUG(dbgs() << "Generic MI Combiner for: " << MF.getName() << '\n');
+
+  MachineOptimizationRemarkEmitter MORE(MF, /*MBFI=*/nullptr);
+
+  bool MFChanged = false;
+  bool Changed;
+
+  do {
+    // Collect all instructions. Do a post order traversal for basic blocks and
+    // insert with list bottom up, so while we pop_back_val, we'll traverse top
+    // down RPOT.
+    Changed = false;
+    GISelWorkList<512> WorkList;
+    for (MachineBasicBlock *MBB : post_order(&MF)) {
+      if (MBB->empty())
+        continue;
+      for (auto MII = MBB->rbegin(), MIE = MBB->rend(); MII != MIE;) {
+        MachineInstr *CurMI = &*MII;
+        ++MII;
+        // Erase dead insts before even adding to the list.
+        if (isTriviallyDead(*CurMI, *MRI)) {
+          LLVM_DEBUG(dbgs() << *CurMI << "Is dead; erasing.\n");
+          CurMI->eraseFromParentAndMarkDBGValuesForRemoval();
+          continue;
+        }
+        WorkList.insert(CurMI);
+      }
+    }
+    // Main Loop. Process the instructions here.
+    while (!WorkList.empty()) {
+      MachineInstr *CurrInst = WorkList.pop_back_val();
+      LLVM_DEBUG(dbgs() << "Try combining " << *CurrInst << "\n";);
+      Changed |= CInfo.combine(*CurrInst, Builder);
+    }
+    MFChanged |= Changed;
+  } while (Changed);
+
+  return MFChanged;
+}