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diff --git a/lib/CodeGen/RegAllocSimple.cpp b/lib/CodeGen/RegAllocSimple.cpp
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-//===-- RegAllocSimple.cpp - A simple generic register allocator ----------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements a simple register allocator. *Very* simple: It immediate
-// spills every value right after it is computed, and it reloads all used
-// operands from the spill area to temporary registers before each instruction.
-// It does not keep values in registers across instructions.
-//
-//===----------------------------------------------------------------------===//
-
-#define DEBUG_TYPE "regalloc"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstr.h"
-#include "llvm/CodeGen/MachineFrameInfo.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/RegAllocRegistry.h"
-#include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/Compiler.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/ADT/STLExtras.h"
-#include <map>
-using namespace llvm;
-
-STATISTIC(NumStores, "Number of stores added");
-STATISTIC(NumLoads , "Number of loads added");
-
-namespace {
- static RegisterRegAlloc
- simpleRegAlloc("simple", "simple register allocator",
- createSimpleRegisterAllocator);
-
- class VISIBILITY_HIDDEN RegAllocSimple : public MachineFunctionPass {
- public:
- static char ID;
- RegAllocSimple() : MachineFunctionPass(&ID) {}
- private:
- MachineFunction *MF;
- const TargetMachine *TM;
- const TargetRegisterInfo *TRI;
- const TargetInstrInfo *TII;
-
- // StackSlotForVirtReg - Maps SSA Regs => frame index on the stack where
- // these values are spilled
- std::map<unsigned, int> StackSlotForVirtReg;
-
- // RegsUsed - Keep track of what registers are currently in use. This is a
- // bitset.
- std::vector<bool> RegsUsed;
-
- // RegClassIdx - Maps RegClass => which index we can take a register
- // from. Since this is a simple register allocator, when we need a register
- // of a certain class, we just take the next available one.
- std::map<const TargetRegisterClass*, unsigned> RegClassIdx;
-
- public:
- virtual const char *getPassName() const {
- return "Simple Register Allocator";
- }
-
- /// runOnMachineFunction - Register allocate the whole function
- bool runOnMachineFunction(MachineFunction &Fn);
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequiredID(PHIEliminationID); // Eliminate PHI nodes
- MachineFunctionPass::getAnalysisUsage(AU);
- }
- private:
- /// AllocateBasicBlock - Register allocate the specified basic block.
- void AllocateBasicBlock(MachineBasicBlock &MBB);
-
- /// getStackSpaceFor - This returns the offset of the specified virtual
- /// register on the stack, allocating space if necessary.
- int getStackSpaceFor(unsigned VirtReg, const TargetRegisterClass *RC);
-
- /// Given a virtual register, return a compatible physical register that is
- /// currently unused.
- ///
- /// Side effect: marks that register as being used until manually cleared
- ///
- unsigned getFreeReg(unsigned virtualReg);
-
- /// Moves value from memory into that register
- unsigned reloadVirtReg(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator I, unsigned VirtReg);
-
- /// Saves reg value on the stack (maps virtual register to stack value)
- void spillVirtReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
- unsigned VirtReg, unsigned PhysReg);
- };
- char RegAllocSimple::ID = 0;
-}
-
-/// getStackSpaceFor - This allocates space for the specified virtual
-/// register to be held on the stack.
-int RegAllocSimple::getStackSpaceFor(unsigned VirtReg,
- const TargetRegisterClass *RC) {
- // Find the location VirtReg would belong...
- std::map<unsigned, int>::iterator I = StackSlotForVirtReg.find(VirtReg);
-
- if (I != StackSlotForVirtReg.end())
- return I->second; // Already has space allocated?
-
- // Allocate a new stack object for this spill location...
- int FrameIdx = MF->getFrameInfo()->CreateStackObject(RC->getSize(),
- RC->getAlignment());
-
- // Assign the slot...
- StackSlotForVirtReg.insert(I, std::make_pair(VirtReg, FrameIdx));
-
- return FrameIdx;
-}
-
-unsigned RegAllocSimple::getFreeReg(unsigned virtualReg) {
- const TargetRegisterClass* RC = MF->getRegInfo().getRegClass(virtualReg);
- TargetRegisterClass::iterator RI = RC->allocation_order_begin(*MF);
-#ifndef NDEBUG
- TargetRegisterClass::iterator RE = RC->allocation_order_end(*MF);
-#endif
-
- while (1) {
- unsigned regIdx = RegClassIdx[RC]++;
- assert(RI+regIdx != RE && "Not enough registers!");
- unsigned PhysReg = *(RI+regIdx);
-
- if (!RegsUsed[PhysReg]) {
- MF->getRegInfo().setPhysRegUsed(PhysReg);
- return PhysReg;
- }
- }
-}
-
-unsigned RegAllocSimple::reloadVirtReg(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator I,
- unsigned VirtReg) {
- const TargetRegisterClass* RC = MF->getRegInfo().getRegClass(VirtReg);
- int FrameIdx = getStackSpaceFor(VirtReg, RC);
- unsigned PhysReg = getFreeReg(VirtReg);
-
- // Add move instruction(s)
- ++NumLoads;
- TII->loadRegFromStackSlot(MBB, I, PhysReg, FrameIdx, RC);
- return PhysReg;
-}
-
-void RegAllocSimple::spillVirtReg(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator I,
- unsigned VirtReg, unsigned PhysReg) {
- const TargetRegisterClass* RC = MF->getRegInfo().getRegClass(VirtReg);
-
- int FrameIdx = getStackSpaceFor(VirtReg, RC);
-
- // Add move instruction(s)
- ++NumStores;
- TII->storeRegToStackSlot(MBB, I, PhysReg, true, FrameIdx, RC);
-}
-
-
-void RegAllocSimple::AllocateBasicBlock(MachineBasicBlock &MBB) {
- // loop over each instruction
- for (MachineBasicBlock::iterator MI = MBB.begin(); MI != MBB.end(); ++MI) {
- // Made to combat the incorrect allocation of r2 = add r1, r1
- std::map<unsigned, unsigned> Virt2PhysRegMap;
-
- RegsUsed.resize(TRI->getNumRegs());
-
- // This is a preliminary pass that will invalidate any registers that are
- // used by the instruction (including implicit uses).
- const TargetInstrDesc &Desc = MI->getDesc();
- const unsigned *Regs;
- if (Desc.ImplicitUses) {
- for (Regs = Desc.ImplicitUses; *Regs; ++Regs)
- RegsUsed[*Regs] = true;
- }
-
- if (Desc.ImplicitDefs) {
- for (Regs = Desc.ImplicitDefs; *Regs; ++Regs) {
- RegsUsed[*Regs] = true;
- MF->getRegInfo().setPhysRegUsed(*Regs);
- }
- }
-
- // Loop over uses, move from memory into registers.
- for (int i = MI->getNumOperands() - 1; i >= 0; --i) {
- MachineOperand &MO = MI->getOperand(i);
-
- if (MO.isReg() && MO.getReg() &&
- TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
- unsigned virtualReg = (unsigned) MO.getReg();
- DOUT << "op: " << MO << "\n";
- DOUT << "\t inst[" << i << "]: ";
- DEBUG(MI->print(*cerr.stream(), TM));
-
- // make sure the same virtual register maps to the same physical
- // register in any given instruction
- unsigned physReg = Virt2PhysRegMap[virtualReg];
- if (physReg == 0) {
- if (MO.isDef()) {
- unsigned TiedOp;
- if (!MI->isRegTiedToUseOperand(i, &TiedOp)) {
- physReg = getFreeReg(virtualReg);
- } else {
- // must be same register number as the source operand that is
- // tied to. This maps a = b + c into b = b + c, and saves b into
- // a's spot.
- assert(MI->getOperand(TiedOp).isReg() &&
- MI->getOperand(TiedOp).getReg() &&
- MI->getOperand(TiedOp).isUse() &&
- "Two address instruction invalid!");
-
- physReg = MI->getOperand(TiedOp).getReg();
- }
- spillVirtReg(MBB, next(MI), virtualReg, physReg);
- } else {
- physReg = reloadVirtReg(MBB, MI, virtualReg);
- Virt2PhysRegMap[virtualReg] = physReg;
- }
- }
- MO.setReg(physReg);
- DOUT << "virt: " << virtualReg << ", phys: " << MO.getReg() << "\n";
- }
- }
- RegClassIdx.clear();
- RegsUsed.clear();
- }
-}
-
-
-/// runOnMachineFunction - Register allocate the whole function
-///
-bool RegAllocSimple::runOnMachineFunction(MachineFunction &Fn) {
- DOUT << "Machine Function\n";
- MF = &Fn;
- TM = &MF->getTarget();
- TRI = TM->getRegisterInfo();
- TII = TM->getInstrInfo();
-
- // Loop over all of the basic blocks, eliminating virtual register references
- for (MachineFunction::iterator MBB = Fn.begin(), MBBe = Fn.end();
- MBB != MBBe; ++MBB)
- AllocateBasicBlock(*MBB);
-
- StackSlotForVirtReg.clear();
- return true;
-}
-
-FunctionPass *llvm::createSimpleRegisterAllocator() {
- return new RegAllocSimple();
-}
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