1 files changed, 74 insertions, 8 deletions

diff --git a/lib/CodeGen/GlobalISel/Combiner.cpp b/lib/CodeGen/GlobalISel/Combiner.cpp
index 0bc5b87de150..45b0e36fd7d9 100644
--- a/lib/CodeGen/GlobalISel/Combiner.cpp
+++ b/lib/CodeGen/GlobalISel/Combiner.cpp
@@ -1,4 +1,4 @@
-//===-- lib/CodeGen/GlobalISel/GICombiner.cpp -----------------------===//
+//===-- lib/CodeGen/GlobalISel/Combiner.cpp -------------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -12,12 +12,15 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/GlobalISel/Combiner.h"
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/CodeGen/GlobalISel/CSEInfo.h"
 #include "llvm/CodeGen/GlobalISel/CombinerInfo.h"
-#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
-#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
+#include "llvm/CodeGen/GlobalISel/CSEMIRBuilder.h"
+#include "llvm/CodeGen/GlobalISel/GISelChangeObserver.h"
 #include "llvm/CodeGen/GlobalISel/GISelWorkList.h"
-#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
 #include "llvm/CodeGen/GlobalISel/Utils.h"
+#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/Support/Debug.h"
 
@@ -25,20 +28,76 @@
 
 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 GISelChangeObserver 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 GISelChangeObserver subclass.
+class WorkListMaintainer : public GISelChangeObserver {
+  using WorkListTy = GISelWorkList<512>;
+  WorkListTy &WorkList;
+  /// The instructions that have been created but we want to report once they
+  /// have their operands. This is only maintained if debug output is requested.
+  SmallPtrSet<const MachineInstr *, 4> CreatedInstrs;
+
+public:
+  WorkListMaintainer(WorkListTy &WorkList)
+      : GISelChangeObserver(), WorkList(WorkList) {}
+  virtual ~WorkListMaintainer() {
+  }
+
+  void erasingInstr(MachineInstr &MI) override {
+    LLVM_DEBUG(dbgs() << "Erased: " << MI << "\n");
+    WorkList.remove(&MI);
+  }
+  void createdInstr(MachineInstr &MI) override {
+    LLVM_DEBUG(dbgs() << "Creating: " << MI << "\n");
+    WorkList.insert(&MI);
+    LLVM_DEBUG(CreatedInstrs.insert(&MI));
+  }
+  void changingInstr(MachineInstr &MI) override {
+    LLVM_DEBUG(dbgs() << "Changing: " << MI << "\n");
+    WorkList.insert(&MI);
+  }
+  void changedInstr(MachineInstr &MI) override {
+    LLVM_DEBUG(dbgs() << "Changed: " << MI << "\n");
+    WorkList.insert(&MI);
+  }
+
+  void reportFullyCreatedInstrs() {
+    LLVM_DEBUG(for (const auto *MI
+                    : CreatedInstrs) {
+      dbgs() << "Created: ";
+      MI->print(dbgs());
+    });
+    LLVM_DEBUG(CreatedInstrs.clear());
+  }
+};
+}
+
 Combiner::Combiner(CombinerInfo &Info, const TargetPassConfig *TPC)
     : CInfo(Info), TPC(TPC) {
   (void)this->TPC; // FIXME: Remove when used.
 }
 
-bool Combiner::combineMachineInstrs(MachineFunction &MF) {
+bool Combiner::combineMachineInstrs(MachineFunction &MF,
+                                    GISelCSEInfo *CSEInfo) {
   // 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;
 
+  Builder =
+      CSEInfo ? make_unique<CSEMIRBuilder>() : make_unique<MachineIRBuilder>();
   MRI = &MF.getRegInfo();
-  Builder.setMF(MF);
+  Builder->setMF(MF);
+  if (CSEInfo)
+    Builder->setCSEInfo(CSEInfo);
 
   LLVM_DEBUG(dbgs() << "Generic MI Combiner for: " << MF.getName() << '\n');
 
@@ -46,6 +105,7 @@ bool Combiner::combineMachineInstrs(MachineFunction &MF) {
 
   bool MFChanged = false;
   bool Changed;
+  MachineIRBuilder &B = *Builder.get();
 
   do {
     // Collect all instructions. Do a post order traversal for basic blocks and
@@ -53,6 +113,11 @@ bool Combiner::combineMachineInstrs(MachineFunction &MF) {
     // down RPOT.
     Changed = false;
     GISelWorkList<512> WorkList;
+    WorkListMaintainer Observer(WorkList);
+    GISelObserverWrapper WrapperObserver(&Observer);
+    if (CSEInfo)
+      WrapperObserver.addObserver(CSEInfo);
+    RAIIDelegateInstaller DelInstall(MF, &WrapperObserver);
     for (MachineBasicBlock *MBB : post_order(&MF)) {
       if (MBB->empty())
         continue;
@@ -71,8 +136,9 @@ bool Combiner::combineMachineInstrs(MachineFunction &MF) {
     // 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);
+      LLVM_DEBUG(dbgs() << "\nTry combining " << *CurrInst;);
+      Changed |= CInfo.combine(WrapperObserver, *CurrInst, B);
+      Observer.reportFullyCreatedInstrs();
     }
     MFChanged |= Changed;
   } while (Changed);