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diff --git a/contrib/llvm/lib/Target/X86/X86FixupLEAs.cpp b/contrib/llvm/lib/Target/X86/X86FixupLEAs.cpp
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+//===-- X86FixupLEAs.cpp - use or replace LEA instructions -----------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the pass which will find instructions which
+// can be re-written as LEA instructions in order to reduce pipeline
+// delays for some models of the Intel Atom family.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "x86-fixup-LEAs"
+#include "X86.h"
+#include "X86InstrInfo.h"
+#include "X86Subtarget.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/CodeGen/LiveVariables.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetInstrInfo.h"
+using namespace llvm;
+
+STATISTIC(NumLEAs, "Number of LEA instructions created");
+
+namespace {
+ class FixupLEAPass : public MachineFunctionPass {
+ enum RegUsageState { RU_NotUsed, RU_Write, RU_Read };
+ static char ID;
+ /// \brief Loop over all of the instructions in the basic block
+ /// replacing applicable instructions with LEA instructions,
+ /// where appropriate.
+ bool processBasicBlock(MachineFunction &MF, MachineFunction::iterator MFI);
+
+ virtual const char *getPassName() const { return "X86 Atom LEA Fixup";}
+
+ /// \brief Given a machine register, look for the instruction
+ /// which writes it in the current basic block. If found,
+ /// try to replace it with an equivalent LEA instruction.
+ /// If replacement succeeds, then also process the the newly created
+ /// instruction.
+ void seekLEAFixup(MachineOperand& p, MachineBasicBlock::iterator& I,
+ MachineFunction::iterator MFI);
+
+ /// \brief Given a memory access or LEA instruction
+ /// whose address mode uses a base and/or index register, look for
+ /// an opportunity to replace the instruction which sets the base or index
+ /// register with an equivalent LEA instruction.
+ void processInstruction(MachineBasicBlock::iterator& I,
+ MachineFunction::iterator MFI);
+
+ /// \brief Determine if an instruction references a machine register
+ /// and, if so, whether it reads or writes the register.
+ RegUsageState usesRegister(MachineOperand& p,
+ MachineBasicBlock::iterator I);
+
+ /// \brief Step backwards through a basic block, looking
+ /// for an instruction which writes a register within
+ /// a maximum of INSTR_DISTANCE_THRESHOLD instruction latency cycles.
+ MachineBasicBlock::iterator searchBackwards(MachineOperand& p,
+ MachineBasicBlock::iterator& I,
+ MachineFunction::iterator MFI);
+
+ /// \brief if an instruction can be converted to an
+ /// equivalent LEA, insert the new instruction into the basic block
+ /// and return a pointer to it. Otherwise, return zero.
+ MachineInstr* postRAConvertToLEA(MachineFunction::iterator &MFI,
+ MachineBasicBlock::iterator &MBBI) const;
+
+ public:
+ FixupLEAPass() : MachineFunctionPass(ID) {}
+
+ /// \brief Loop over all of the basic blocks,
+ /// replacing instructions by equivalent LEA instructions
+ /// if needed and when possible.
+ virtual bool runOnMachineFunction(MachineFunction &MF);
+
+ private:
+ MachineFunction *MF;
+ const TargetMachine *TM;
+ const TargetInstrInfo *TII; // Machine instruction info.
+
+ };
+ char FixupLEAPass::ID = 0;
+}
+
+MachineInstr *
+FixupLEAPass::postRAConvertToLEA(MachineFunction::iterator &MFI,
+ MachineBasicBlock::iterator &MBBI) const {
+ MachineInstr* MI = MBBI;
+ MachineInstr* NewMI;
+ switch (MI->getOpcode()) {
+ case X86::MOV32rr:
+ case X86::MOV64rr: {
+ const MachineOperand& Src = MI->getOperand(1);
+ const MachineOperand& Dest = MI->getOperand(0);
+ NewMI = BuildMI(*MF, MI->getDebugLoc(),
+ TII->get( MI->getOpcode() == X86::MOV32rr ? X86::LEA32r : X86::LEA64r))
+ .addOperand(Dest)
+ .addOperand(Src).addImm(1).addReg(0).addImm(0).addReg(0);
+ MFI->insert(MBBI, NewMI); // Insert the new inst
+ return NewMI;
+ }
+ case X86::ADD64ri32:
+ case X86::ADD64ri8:
+ case X86::ADD64ri32_DB:
+ case X86::ADD64ri8_DB:
+ case X86::ADD32ri:
+ case X86::ADD32ri8:
+ case X86::ADD32ri_DB:
+ case X86::ADD32ri8_DB:
+ case X86::ADD16ri:
+ case X86::ADD16ri8:
+ case X86::ADD16ri_DB:
+ case X86::ADD16ri8_DB:
+ if (!MI->getOperand(2).isImm()) {
+ // convertToThreeAddress will call getImm()
+ // which requires isImm() to be true
+ return 0;
+ }
+ }
+ return TII->convertToThreeAddress(MFI, MBBI, 0);
+}
+
+FunctionPass *llvm::createX86FixupLEAs() {
+ return new FixupLEAPass();
+}
+
+bool FixupLEAPass::runOnMachineFunction(MachineFunction &Func) {
+ MF = &Func;
+ TII = Func.getTarget().getInstrInfo();
+ TM = &MF->getTarget();
+
+ DEBUG(dbgs() << "Start X86FixupLEAs\n";);
+ // Process all basic blocks.
+ for (MachineFunction::iterator I = Func.begin(), E = Func.end(); I != E; ++I)
+ processBasicBlock(Func, I);
+ DEBUG(dbgs() << "End X86FixupLEAs\n";);
+
+ return true;
+}
+
+FixupLEAPass::RegUsageState FixupLEAPass::usesRegister(MachineOperand& p,
+ MachineBasicBlock::iterator I) {
+ RegUsageState RegUsage = RU_NotUsed;
+ MachineInstr* MI = I;
+
+ for (unsigned int i = 0; i < MI->getNumOperands(); ++i) {
+ MachineOperand& opnd = MI->getOperand(i);
+ if (opnd.isReg() && opnd.getReg() == p.getReg()){
+ if (opnd.isDef())
+ return RU_Write;
+ RegUsage = RU_Read;
+ }
+ }
+ return RegUsage;
+}
+
+/// getPreviousInstr - Given a reference to an instruction in a basic
+/// block, return a reference to the previous instruction in the block,
+/// wrapping around to the last instruction of the block if the block
+/// branches to itself.
+static inline bool getPreviousInstr(MachineBasicBlock::iterator& I,
+ MachineFunction::iterator MFI) {
+ if (I == MFI->begin()) {
+ if (MFI->isPredecessor(MFI)) {
+ I = --MFI->end();
+ return true;
+ }
+ else
+ return false;
+ }
+ --I;
+ return true;
+}
+
+MachineBasicBlock::iterator FixupLEAPass::searchBackwards(MachineOperand& p,
+ MachineBasicBlock::iterator& I,
+ MachineFunction::iterator MFI) {
+ int InstrDistance = 1;
+ MachineBasicBlock::iterator CurInst;
+ static const int INSTR_DISTANCE_THRESHOLD = 5;
+
+ CurInst = I;
+ bool Found;
+ Found = getPreviousInstr(CurInst, MFI);
+ while( Found && I != CurInst) {
+ if (CurInst->isCall() || CurInst->isInlineAsm())
+ break;
+ if (InstrDistance > INSTR_DISTANCE_THRESHOLD)
+ break; // too far back to make a difference
+ if (usesRegister(p, CurInst) == RU_Write){
+ return CurInst;
+ }
+ InstrDistance += TII->getInstrLatency(TM->getInstrItineraryData(), CurInst);
+ Found = getPreviousInstr(CurInst, MFI);
+ }
+ return 0;
+}
+
+void FixupLEAPass::processInstruction(MachineBasicBlock::iterator& I,
+ MachineFunction::iterator MFI) {
+ // Process a load, store, or LEA instruction.
+ MachineInstr *MI = I;
+ int opcode = MI->getOpcode();
+ const MCInstrDesc& Desc = MI->getDesc();
+ int AddrOffset = X86II::getMemoryOperandNo(Desc.TSFlags, opcode);
+ if (AddrOffset >= 0) {
+ AddrOffset += X86II::getOperandBias(Desc);
+ MachineOperand& p = MI->getOperand(AddrOffset + X86::AddrBaseReg);
+ if (p.isReg() && p.getReg() != X86::ESP) {
+ seekLEAFixup(p, I, MFI);
+ }
+ MachineOperand& q = MI->getOperand(AddrOffset + X86::AddrIndexReg);
+ if (q.isReg() && q.getReg() != X86::ESP) {
+ seekLEAFixup(q, I, MFI);
+ }
+ }
+}
+
+void FixupLEAPass::seekLEAFixup(MachineOperand& p,
+ MachineBasicBlock::iterator& I,
+ MachineFunction::iterator MFI) {
+ MachineBasicBlock::iterator MBI = searchBackwards(p, I, MFI);
+ if (MBI) {
+ MachineInstr* NewMI = postRAConvertToLEA(MFI, MBI);
+ if (NewMI) {
+ ++NumLEAs;
+ DEBUG(dbgs() << "Candidate to replace:"; MBI->dump(););
+ // now to replace with an equivalent LEA...
+ DEBUG(dbgs() << "Replaced by: "; NewMI->dump(););
+ MFI->erase(MBI);
+ MachineBasicBlock::iterator J =
+ static_cast<MachineBasicBlock::iterator> (NewMI);
+ processInstruction(J, MFI);
+ }
+ }
+}
+
+bool FixupLEAPass::processBasicBlock(MachineFunction &MF,
+ MachineFunction::iterator MFI) {
+
+ for (MachineBasicBlock::iterator I = MFI->begin(); I != MFI->end(); ++I)
+ processInstruction(I, MFI);
+ return false;
+}
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