1 files changed, 120 insertions, 0 deletions
diff --git a/llvm/lib/Target/SystemZ/SystemZCopyPhysRegs.cpp b/llvm/lib/Target/SystemZ/SystemZCopyPhysRegs.cpp
new file mode 100644
index 0000000000000..7d21d29d270e3
--- /dev/null
+++ b/llvm/lib/Target/SystemZ/SystemZCopyPhysRegs.cpp
@@ -0,0 +1,120 @@
+//===---------- SystemZPhysRegCopy.cpp - Handle phys reg copies -----------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass makes sure that a COPY of a physical register will be
+// implementable after register allocation in copyPhysReg() (this could be
+// done in EmitInstrWithCustomInserter() instead if COPY instructions would
+// be passed to it).
+//
+//===----------------------------------------------------------------------===//
+
+#include "SystemZMachineFunctionInfo.h"
+#include "SystemZTargetMachine.h"
+#include "llvm/CodeGen/MachineDominators.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/TargetInstrInfo.h"
+#include "llvm/CodeGen/TargetRegisterInfo.h"
+#include "llvm/Target/TargetMachine.h"
+
+using namespace llvm;
+
+#define SYSTEMZ_COPYPHYSREGS_NAME "SystemZ Copy Physregs"
+
+namespace llvm {
+  void initializeSystemZCopyPhysRegsPass(PassRegistry&);
+}
+
+namespace {
+
+class SystemZCopyPhysRegs : public MachineFunctionPass {
+public:
+  static char ID;
+  SystemZCopyPhysRegs()
+    : MachineFunctionPass(ID), TII(nullptr), MRI(nullptr) {
+    initializeSystemZCopyPhysRegsPass(*PassRegistry::getPassRegistry());
+  }
+
+  StringRef getPassName() const override { return SYSTEMZ_COPYPHYSREGS_NAME; }
+
+  bool runOnMachineFunction(MachineFunction &MF) override;
+  void getAnalysisUsage(AnalysisUsage &AU) const override;
+
+private:
+
+  bool visitMBB(MachineBasicBlock &MBB);
+
+  const SystemZInstrInfo *TII;
+  MachineRegisterInfo *MRI;
+};
+
+char SystemZCopyPhysRegs::ID = 0;
+
+} // end anonymous namespace
+
+INITIALIZE_PASS(SystemZCopyPhysRegs, "systemz-copy-physregs",
+                SYSTEMZ_COPYPHYSREGS_NAME, false, false)
+
+FunctionPass *llvm::createSystemZCopyPhysRegsPass(SystemZTargetMachine &TM) {
+  return new SystemZCopyPhysRegs();
+}
+
+void SystemZCopyPhysRegs::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.setPreservesCFG();
+  MachineFunctionPass::getAnalysisUsage(AU);
+}
+
+bool SystemZCopyPhysRegs::visitMBB(MachineBasicBlock &MBB) {
+  bool Modified = false;
+
+  // Certain special registers can only be copied from a subset of the
+  // default register class of the type. It is therefore necessary to create
+  // the target copy instructions before regalloc instead of in copyPhysReg().
+  for (MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end();
+       MBBI != E; ) {
+    MachineInstr *MI = &*MBBI++;
+    if (!MI->isCopy())
+      continue;
+
+    DebugLoc DL = MI->getDebugLoc();
+    Register SrcReg = MI->getOperand(1).getReg();
+    Register DstReg = MI->getOperand(0).getReg();
+    if (DstReg.isVirtual() &&
+        (SrcReg == SystemZ::CC || SystemZ::AR32BitRegClass.contains(SrcReg))) {
+      Register Tmp = MRI->createVirtualRegister(&SystemZ::GR32BitRegClass);
+      if (SrcReg == SystemZ::CC)
+        BuildMI(MBB, MI, DL, TII->get(SystemZ::IPM), Tmp);
+      else
+        BuildMI(MBB, MI, DL, TII->get(SystemZ::EAR), Tmp).addReg(SrcReg);
+      MI->getOperand(1).setReg(Tmp);
+      Modified = true;
+    }
+    else if (SrcReg.isVirtual() &&
+             SystemZ::AR32BitRegClass.contains(DstReg)) {
+      Register Tmp = MRI->createVirtualRegister(&SystemZ::GR32BitRegClass);
+      MI->getOperand(0).setReg(Tmp);
+      BuildMI(MBB, MBBI, DL, TII->get(SystemZ::SAR), DstReg).addReg(Tmp);
+      Modified = true;
+    }
+  }
+
+  return Modified;
+}
+
+bool SystemZCopyPhysRegs::runOnMachineFunction(MachineFunction &F) {
+  TII = static_cast<const SystemZInstrInfo *>(F.getSubtarget().getInstrInfo());
+  MRI = &F.getRegInfo();
+
+  bool Modified = false;
+  for (auto &MBB : F)
+    Modified |= visitMBB(MBB);
+
+  return Modified;
+}
+