1 files changed, 164 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/contrib/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
new file mode 100644
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+++ b/contrib/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -0,0 +1,164 @@
+//===-- llvm/CodeGen/GlobalISel/IRTranslator.cpp - IRTranslator --*- 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 IRTranslator class.
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/GlobalISel/IRTranslator.h"
+
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/CodeGen/GlobalISel/CallLowering.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/IR/Constant.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Type.h"
+#include "llvm/IR/Value.h"
+#include "llvm/Target/TargetLowering.h"
+
+#define DEBUG_TYPE "irtranslator"
+
+using namespace llvm;
+
+char IRTranslator::ID = 0;
+INITIALIZE_PASS(IRTranslator, "irtranslator", "IRTranslator LLVM IR -> MI",
+                false, false);
+
+IRTranslator::IRTranslator() : MachineFunctionPass(ID), MRI(nullptr) {
+  initializeIRTranslatorPass(*PassRegistry::getPassRegistry());
+}
+
+unsigned IRTranslator::getOrCreateVReg(const Value &Val) {
+  unsigned &ValReg = ValToVReg[&Val];
+  // Check if this is the first time we see Val.
+  if (!ValReg) {
+    // Fill ValRegsSequence with the sequence of registers
+    // we need to concat together to produce the value.
+    assert(Val.getType()->isSized() &&
+           "Don't know how to create an empty vreg");
+    assert(!Val.getType()->isAggregateType() && "Not yet implemented");
+    unsigned Size = Val.getType()->getPrimitiveSizeInBits();
+    unsigned VReg = MRI->createGenericVirtualRegister(Size);
+    ValReg = VReg;
+    assert(!isa<Constant>(Val) && "Not yet implemented");
+  }
+  return ValReg;
+}
+
+MachineBasicBlock &IRTranslator::getOrCreateBB(const BasicBlock &BB) {
+  MachineBasicBlock *&MBB = BBToMBB[&BB];
+  if (!MBB) {
+    MachineFunction &MF = MIRBuilder.getMF();
+    MBB = MF.CreateMachineBasicBlock();
+    MF.push_back(MBB);
+  }
+  return *MBB;
+}
+
+bool IRTranslator::translateBinaryOp(unsigned Opcode, const Instruction &Inst) {
+  // Get or create a virtual register for each value.
+  // Unless the value is a Constant => loadimm cst?
+  // or inline constant each time?
+  // Creation of a virtual register needs to have a size.
+  unsigned Op0 = getOrCreateVReg(*Inst.getOperand(0));
+  unsigned Op1 = getOrCreateVReg(*Inst.getOperand(1));
+  unsigned Res = getOrCreateVReg(Inst);
+  MIRBuilder.buildInstr(Opcode, Inst.getType(), Res, Op0, Op1);
+  return true;
+}
+
+bool IRTranslator::translateReturn(const Instruction &Inst) {
+  assert(isa<ReturnInst>(Inst) && "Return expected");
+  const Value *Ret = cast<ReturnInst>(Inst).getReturnValue();
+  // The target may mess up with the insertion point, but
+  // this is not important as a return is the last instruction
+  // of the block anyway.
+  return CLI->lowerReturn(MIRBuilder, Ret, !Ret ? 0 : getOrCreateVReg(*Ret));
+}
+
+bool IRTranslator::translateBr(const Instruction &Inst) {
+  assert(isa<BranchInst>(Inst) && "Branch expected");
+  const BranchInst &BrInst = *cast<BranchInst>(&Inst);
+  if (BrInst.isUnconditional()) {
+    const BasicBlock &BrTgt = *cast<BasicBlock>(BrInst.getOperand(0));
+    MachineBasicBlock &TgtBB = getOrCreateBB(BrTgt);
+    MIRBuilder.buildInstr(TargetOpcode::G_BR, BrTgt.getType(), TgtBB);
+  } else {
+    assert(0 && "Not yet implemented");
+  }
+  // Link successors.
+  MachineBasicBlock &CurBB = MIRBuilder.getMBB();
+  for (const BasicBlock *Succ : BrInst.successors())
+    CurBB.addSuccessor(&getOrCreateBB(*Succ));
+  return true;
+}
+
+bool IRTranslator::translate(const Instruction &Inst) {
+  MIRBuilder.setDebugLoc(Inst.getDebugLoc());
+  switch(Inst.getOpcode()) {
+  case Instruction::Add:
+    return translateBinaryOp(TargetOpcode::G_ADD, Inst);
+  case Instruction::Or:
+    return translateBinaryOp(TargetOpcode::G_OR, Inst);
+  case Instruction::Br:
+    return translateBr(Inst);
+  case Instruction::Ret:
+    return translateReturn(Inst);
+
+  default:
+    llvm_unreachable("Opcode not supported");
+  }
+}
+
+
+void IRTranslator::finalize() {
+  // Release the memory used by the different maps we
+  // needed during the translation.
+  ValToVReg.clear();
+  Constants.clear();
+}
+
+bool IRTranslator::runOnMachineFunction(MachineFunction &MF) {
+  const Function &F = *MF.getFunction();
+  if (F.empty())
+    return false;
+  CLI = MF.getSubtarget().getCallLowering();
+  MIRBuilder.setMF(MF);
+  MRI = &MF.getRegInfo();
+  // Setup the arguments.
+  MachineBasicBlock &MBB = getOrCreateBB(F.front());
+  MIRBuilder.setMBB(MBB);
+  SmallVector<unsigned, 8> VRegArgs;
+  for (const Argument &Arg: F.args())
+    VRegArgs.push_back(getOrCreateVReg(Arg));
+  bool Succeeded =
+      CLI->lowerFormalArguments(MIRBuilder, F.getArgumentList(), VRegArgs);
+  if (!Succeeded)
+    report_fatal_error("Unable to lower arguments");
+
+  for (const BasicBlock &BB: F) {
+    MachineBasicBlock &MBB = getOrCreateBB(BB);
+    // Set the insertion point of all the following translations to
+    // the end of this basic block.
+    MIRBuilder.setMBB(MBB);
+    for (const Instruction &Inst: BB) {
+      bool Succeeded = translate(Inst);
+      if (!Succeeded) {
+        DEBUG(dbgs() << "Cannot translate: " << Inst << '\n');
+        report_fatal_error("Unable to translate instruction");
+      }
+    }
+  }
+
+  // Now that the MachineFrameInfo has been configured, no further changes to
+  // the reserved registers are possible.
+  MRI->freezeReservedRegs(MF);
+
+  return false;
+}