1 files changed, 109 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/ARM/ARMInstructionSelector.cpp b/contrib/llvm/lib/Target/ARM/ARMInstructionSelector.cpp
new file mode 100644
index 0000000..2bdbe4f
--- /dev/null
+++ b/contrib/llvm/lib/Target/ARM/ARMInstructionSelector.cpp
@@ -0,0 +1,109 @@
+//===- ARMInstructionSelector.cpp ----------------------------*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file implements the targeting of the InstructionSelector class for ARM.
+/// \todo This should be generated by TableGen.
+//===----------------------------------------------------------------------===//
+
+#include "ARMInstructionSelector.h"
+#include "ARMRegisterBankInfo.h"
+#include "ARMSubtarget.h"
+#include "ARMTargetMachine.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Support/Debug.h"
+
+#define DEBUG_TYPE "arm-isel"
+
+using namespace llvm;
+
+#ifndef LLVM_BUILD_GLOBAL_ISEL
+#error "You shouldn't build this"
+#endif
+
+ARMInstructionSelector::ARMInstructionSelector(const ARMSubtarget &STI,
+                                               const ARMRegisterBankInfo &RBI)
+    : InstructionSelector(), TII(*STI.getInstrInfo()),
+      TRI(*STI.getRegisterInfo()), RBI(RBI) {}
+
+static bool selectCopy(MachineInstr &I, const TargetInstrInfo &TII,
+                       MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI,
+                       const RegisterBankInfo &RBI) {
+  unsigned DstReg = I.getOperand(0).getReg();
+  if (TargetRegisterInfo::isPhysicalRegister(DstReg))
+    return true;
+
+  const RegisterBank *RegBank = RBI.getRegBank(DstReg, MRI, TRI);
+  (void)RegBank;
+  assert(RegBank && "Can't get reg bank for virtual register");
+
+  const unsigned DstSize = MRI.getType(DstReg).getSizeInBits();
+  (void)DstSize;
+  unsigned SrcReg = I.getOperand(1).getReg();
+  const unsigned SrcSize = RBI.getSizeInBits(SrcReg, MRI, TRI);
+  (void)SrcSize;
+  assert((DstSize == SrcSize ||
+          // Copies are a means to setup initial types, the number of
+          // bits may not exactly match.
+          (TargetRegisterInfo::isPhysicalRegister(SrcReg) &&
+           DstSize <= SrcSize)) &&
+         "Copy with different width?!");
+
+  assert(RegBank->getID() == ARM::GPRRegBankID && "Unsupported reg bank");
+  const TargetRegisterClass *RC = &ARM::GPRRegClass;
+
+  // No need to constrain SrcReg. It will get constrained when
+  // we hit another of its uses or its defs.
+  // Copies do not have constraints.
+  if (!RBI.constrainGenericRegister(DstReg, *RC, MRI)) {
+    DEBUG(dbgs() << "Failed to constrain " << TII.getName(I.getOpcode())
+                 << " operand\n");
+    return false;
+  }
+  return true;
+}
+
+bool ARMInstructionSelector::select(MachineInstr &I) const {
+  assert(I.getParent() && "Instruction should be in a basic block!");
+  assert(I.getParent()->getParent() && "Instruction should be in a function!");
+
+  auto &MBB = *I.getParent();
+  auto &MF = *MBB.getParent();
+  auto &MRI = MF.getRegInfo();
+
+  if (!isPreISelGenericOpcode(I.getOpcode())) {
+    if (I.isCopy())
+      return selectCopy(I, TII, MRI, TRI, RBI);
+
+    return true;
+  }
+
+  MachineInstrBuilder MIB{MF, I};
+
+  using namespace TargetOpcode;
+  switch (I.getOpcode()) {
+  case G_ADD:
+    I.setDesc(TII.get(ARM::ADDrr));
+    AddDefaultCC(AddDefaultPred(MIB));
+    break;
+  case G_FRAME_INDEX:
+    // Add 0 to the given frame index and hope it will eventually be folded into
+    // the user(s).
+    I.setDesc(TII.get(ARM::ADDri));
+    AddDefaultCC(AddDefaultPred(MIB.addImm(0)));
+    break;
+  case G_LOAD:
+    I.setDesc(TII.get(ARM::LDRi12));
+    AddDefaultPred(MIB.addImm(0));
+    break;
+  default:
+    return false;
+  }
+
+  return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
+}