Examples with Operand org.jikesrvm.compilers.opt.ir.operand.Operand used on opensource projects

Example 26 with Operand

use of org.jikesrvm.compilers.opt.ir.operand.Operand in project JikesRVM by JikesRVM.

the class LoopVersioning method generateNullCheckBranchBlocks.

/**
 * Generate null check branch blocks
 *
 * @param loop the current loop where checks are being eliminated
 * @param checksToEliminate all of the checks that are being eliminated in the pass
 * @param optimalRegMap a map from original register to the register used in the optimal loop
 * @param block the block to generate code into
 * @param unoptimizedLoopEntry entry to the unoptimized loop for if the check fails
 * @return the new block to generate code into
 */
private BasicBlock generateNullCheckBranchBlocks(AnnotatedLSTNode loop, ArrayList<Instruction> checksToEliminate, HashMap<Register, Register> optimalRegMap, BasicBlock block, BasicBlock unoptimizedLoopEntry) {
    // Map of already generated null check references to their
    // corresponding guard result
    HashMap<Register, Operand> refToGuardMap = new HashMap<Register, Operand>();
    // Iterate over checks
    for (Instruction instr : checksToEliminate) {
        // Is this a null check
        if (NullCheck.conforms(instr)) {
            // the generated branch instruction
            Instruction branch;
            // the reference to compare
            Operand ref = AnnotatedLSTNode.follow(NullCheck.getRef(instr));
            // the guard result to define
            RegisterOperand guardResult = NullCheck.getGuardResult(instr).copyRO();
            guardResult.setRegister(optimalRegMap.get(guardResult.getRegister()));
            // check if we've generated this test already
            if (ref.isRegister() && refToGuardMap.containsKey(ref.asRegister().getRegister())) {
                // yes - generate just a guard move
                branch = Move.create(GUARD_MOVE, guardResult, refToGuardMap.get(ref.asRegister().getRegister()).copy());
                branch.setBytecodeIndex(SYNTH_LOOP_VERSIONING_BCI);
                block.appendInstruction(branch);
            } else {
                // check if we can just move a guard from the loop predecessors
                RegisterOperand guard = nullCheckPerformedInLoopPredecessors(loop.header, instr);
                if (guard != null) {
                    // yes - generate just a guard move
                    branch = Move.create(GUARD_MOVE, guardResult, guard.copyRO());
                    branch.setBytecodeIndex(SYNTH_LOOP_VERSIONING_BCI);
                    block.appendInstruction(branch);
                } else {
                    // generate explicit null test
                    branch = IfCmp.create(REF_IFCMP, guardResult, ref.copy(), new NullConstantOperand(), ConditionOperand.EQUAL(), unoptimizedLoopEntry.makeJumpTarget(), BranchProfileOperand.unlikely());
                    if (ref.isRegister()) {
                        refToGuardMap.put(ref.asRegister().getRegister(), guardResult);
                    }
                    branch.setBytecodeIndex(SYNTH_LOOP_VERSIONING_BCI);
                    block.appendInstruction(branch);
                    // Adjust block
                    block.insertOut(unoptimizedLoopEntry);
                    BasicBlock new_block = block.createSubBlock(SYNTH_LOOP_VERSIONING_BCI, ir);
                    BasicBlock temp = (BasicBlock) block.next;
                    ir.cfg.breakCodeOrder(block, temp);
                    ir.cfg.linkInCodeOrder(block, new_block);
                    ir.cfg.linkInCodeOrder(new_block, temp);
                    block.insertOut(new_block);
                    block = new_block;
                }
            }
        }
    }
    return block;
}

Example 27 with Operand

use of org.jikesrvm.compilers.opt.ir.operand.Operand in project JikesRVM by JikesRVM.

the class LoopVersioning method getListOfChecksToEliminate.

/**
 * Create a list of instructions to be eliminated
 * @param loop the loop to examine
 * @param instrToEliminate the instructions to remove
 */
private void getListOfChecksToEliminate(AnnotatedLSTNode loop, ArrayList<Instruction> instrToEliminate) {
    ArrayList<Instruction> nullChecks = new ArrayList<Instruction>();
    ArrayList<Instruction> oddBoundChecks = new ArrayList<Instruction>();
    Enumeration<BasicBlock> blocks = loop.getBasicBlocks();
    while (blocks.hasMoreElements()) {
        BasicBlock block = blocks.nextElement();
        IREnumeration.AllInstructionsEnum instructions = new IREnumeration.AllInstructionsEnum(ir, block);
        while (instructions.hasMoreElements()) {
            Instruction instruction = instructions.nextElement();
            if (NullCheck.conforms(instruction)) {
                if (loop.isInvariant(NullCheck.getRef(instruction))) {
                    instrToEliminate.add(instruction);
                    nullChecks.add(instruction);
                }
            } else if (loop.isMonotonic() && BoundsCheck.conforms(instruction)) {
                if (loop.isInvariant(BoundsCheck.getRef(instruction))) {
                    if (loop.isRelatedToIterator(BoundsCheck.getIndex(instruction))) {
                        if (loop.isInvariant(BoundsCheck.getGuard(instruction))) {
                            instrToEliminate.add(instruction);
                        } else {
                            // Null check isn't invariant but reference was, check
                            // null check will be eliminated at end of loop
                            oddBoundChecks.add(instruction);
                        }
                    }
                }
            }
        }
    }
    // it will be in the optimized loop as we'll have eliminated it
    for (Instruction oddBoundCheck : oddBoundChecks) {
        Operand guard = BoundsCheck.getGuard(oddBoundCheck);
        for (Instruction nullCheck : nullChecks) {
            if (guard.similar(NullCheck.getGuardResult(nullCheck))) {
                instrToEliminate.add(oddBoundCheck);
                break;
            }
        }
    }
}

Example 28 with Operand

use of org.jikesrvm.compilers.opt.ir.operand.Operand in project JikesRVM by JikesRVM.

the class LoopVersioning method modifyOriginalLoop.

/*
   * TODO Convert to JavaDoc and add missing tags.
   * <p>
   * Remove loop and replace register definitions in the original loop
   * with phi instructions
   */
private void modifyOriginalLoop(AnnotatedLSTNode loop, ArrayList<Instruction> phiInstructions, ArrayList<Instruction> definingInstrInOriginalLoop, HashMap<Register, Register> subOptimalRegMap, HashMap<Register, Register> optimalRegMap) {
    // Remove instructions from loop header and exit, remove other
    // loop body blocks
    Enumeration<BasicBlock> blocks = loop.getBasicBlocks();
    while (blocks.hasMoreElements()) {
        BasicBlock block = blocks.nextElement();
        if ((block == loop.header) || (block == loop.exit)) {
            IREnumeration.AllInstructionsEnum instructions = new IREnumeration.AllInstructionsEnum(ir, block);
            while (instructions.hasMoreElements()) {
                Instruction instruction = instructions.nextElement();
                if (!BBend.conforms(instruction) && !Label.conforms(instruction)) {
                    instruction.remove();
                }
            }
        } else {
            ir.cfg.removeFromCFGAndCodeOrder(block);
        }
    }
    // Place phi instructions in loop header
    for (int i = 0; i < phiInstructions.size(); i++) {
        Instruction origInstr = definingInstrInOriginalLoop.get(i);
        // Did the original instructions value escape the loop?
        if (origInstr != null) {
            // Was this a phi of a phi?
            if (Phi.conforms(origInstr)) {
                Instruction phi = phiInstructions.get(i);
                boolean phiHasUnoptimizedArg = Phi.getNumberOfValues(phi) == 2;
                // Phi of a phi - so make sure that we get the value to escape the loop, not the value at the loop header
                boolean fixed = false;
                for (int index = 0; index < Phi.getNumberOfPreds(origInstr); index++) {
                    BasicBlockOperand predOp = Phi.getPred(origInstr, index);
                    // Only worry about values who are on the backward branch
                    if (predOp.block == loop.exit) {
                        if (fixed) {
                            // We've tried to do 2 replaces => something wrong
                            SSA.printInstructions(ir);
                            OptimizingCompilerException.UNREACHABLE("LoopVersioning", "Phi node in loop header with multiple in loop predecessors");
                        }
                        Operand rval = Phi.getValue(origInstr, index);
                        if (rval.isRegister()) {
                            // Sort out registers
                            Register origRegPhiRval = rval.asRegister().getRegister();
                            Register subOptRegPhiRval;
                            Register optRegPhiRval;
                            if (!subOptimalRegMap.containsKey(origRegPhiRval)) {
                                // Register comes from loop exit but it wasn't defined in the loop
                                subOptRegPhiRval = origRegPhiRval;
                                optRegPhiRval = origRegPhiRval;
                            } else {
                                subOptRegPhiRval = subOptimalRegMap.get(origRegPhiRval);
                                optRegPhiRval = optimalRegMap.get(origRegPhiRval);
                            }
                            if (phiHasUnoptimizedArg) {
                                Phi.getValue(phi, UNOPTIMIZED_LOOP_OPERAND).asRegister().setRegister(subOptRegPhiRval);
                            }
                            Phi.getValue(phi, OPTIMIZED_LOOP_OPERAND).asRegister().setRegister(optRegPhiRval);
                        } else if (rval.isConstant()) {
                            // Sort out constants
                            if (phiHasUnoptimizedArg) {
                                Phi.setValue(phi, UNOPTIMIZED_LOOP_OPERAND, rval.copy());
                            }
                            Phi.setValue(phi, OPTIMIZED_LOOP_OPERAND, rval.copy());
                        } else if (rval instanceof HeapOperand) {
                            // Sort out heap variables
                            // Cast to generic type
                            @SuppressWarnings("unchecked") HeapVariable<Object> origPhiRval = ((HeapOperand) rval).value;
                            HeapVariable<Object> subOptPhiRval;
                            HeapVariable<Object> optPhiRval;
                            if (true) /*subOptimalRegMap.containsKey(origPhiRval) == false*/
                            {
                                // currently we only expect to optimise scalar SSA
                                // form
                                subOptPhiRval = origPhiRval;
                                optPhiRval = origPhiRval;
                            } else {
                            /*
                  subOptPhiRval   = (HeapVariable)subOptimalRegMap.get(origPhiRval);
                  optPhiRval      = (HeapVariable)optimalRegMap.get(origPhiRval);
                  */
                            }
                            if (phiHasUnoptimizedArg) {
                                Phi.setValue(phi, UNOPTIMIZED_LOOP_OPERAND, new HeapOperand<Object>(subOptPhiRval));
                            }
                            Phi.setValue(phi, OPTIMIZED_LOOP_OPERAND, new HeapOperand<Object>(optPhiRval));
                        } else {
                            OptimizingCompilerException.UNREACHABLE("LoopVersioning", "Unknown operand type", rval.toString());
                        }
                        fixed = true;
                    }
                }
            }
            // Add back to loop
            loop.header.appendInstruction(phiInstructions.get(i));
        }
    }
    // Remove original loop and branch to loop successor
    Instruction tempInstr;
    if (loop.header != loop.exit) {
        tempInstr = Goto.create(GOTO, loop.exit.makeJumpTarget());
        tempInstr.setBytecodeIndex(SYNTH_LOOP_VERSIONING_BCI);
        loop.header.appendInstruction(tempInstr);
        loop.header.deleteNormalOut();
        loop.header.insertOut(loop.exit);
    }
    tempInstr = Goto.create(GOTO, loop.successor.makeJumpTarget());
    tempInstr.setBytecodeIndex(SYNTH_LOOP_VERSIONING_BCI);
    loop.exit.appendInstruction(tempInstr);
    loop.exit.deleteNormalOut();
    loop.exit.insertOut(loop.successor);
}

Example 29 with Operand

use of org.jikesrvm.compilers.opt.ir.operand.Operand in project JikesRVM by JikesRVM.

the class LoopVersioning method createCloneLoop.

/**
 * Create a clone of the loop replacing definitions in the cloned
 * loop with those found in the register map
 * @param loop - loop to clone
 * @param regMap - mapping of original definition to new
 * definition
 * @param regToBlockMap mapping of registers to new, unoptimized blocks. This starts
 *  empty and will be filled during execution of the method.
 * @return a mapping from original BBs to created BBs
 */
private HashMap<BasicBlock, BasicBlock> createCloneLoop(AnnotatedLSTNode loop, HashMap<Register, Register> regMap, HashMap<Register, BasicBlock> regToBlockMap) {
    HashMap<BasicBlock, BasicBlock> originalToCloneBBMap = new HashMap<BasicBlock, BasicBlock>();
    // After the newly created loop goto the old loop header
    originalToCloneBBMap.put(loop.successor, loop.header);
    // Create an empty block to be the loop predecessor
    BasicBlock new_pred = loop.header.createSubBlock(SYNTH_LOOP_VERSIONING_BCI, ir);
    ir.cfg.linkInCodeOrder(ir.cfg.lastInCodeOrder(), new_pred);
    originalToCloneBBMap.put(loop.predecessor, new_pred);
    // Create copy blocks
    Enumeration<BasicBlock> blocks = loop.getBasicBlocks();
    while (blocks.hasMoreElements()) {
        BasicBlock block = blocks.nextElement();
        // get rid of fall through edges to aid recomputeNormalOuts
        block.killFallThrough();
        // Create copy and register mapping
        BasicBlock copy = block.copyWithoutLinks(ir);
        originalToCloneBBMap.put(block, copy);
        // Link into code order
        ir.cfg.linkInCodeOrder(ir.cfg.lastInCodeOrder(), copy);
        // Alter register definitions and uses in copy
        IREnumeration.AllInstructionsEnum instructions = new IREnumeration.AllInstructionsEnum(ir, copy);
        while (instructions.hasMoreElements()) {
            Instruction instruction = instructions.nextElement();
            Enumeration<Operand> operands = instruction.getDefs();
            while (operands.hasMoreElements()) {
                Operand operand = operands.nextElement();
                if (operand.isRegister()) {
                    Register register = operand.asRegister().getRegister();
                    if (regMap.containsKey(register)) {
                        instruction.replaceRegister(register, regMap.get(register));
                        regToBlockMap.put(regMap.get(register), copy);
                    }
                }
            }
            operands = instruction.getUses();
            while (operands.hasMoreElements()) {
                Operand operand = operands.nextElement();
                if (operand instanceof RegisterOperand) {
                    Register register = operand.asRegister().getRegister();
                    if (regMap.containsKey(register)) {
                        instruction.replaceRegister(register, regMap.get(register));
                    }
                }
            }
        }
    }
    // Fix up outs
    // loop predecessor
    new_pred.redirectOuts(loop.header, originalToCloneBBMap.get(loop.header), ir);
    // loop blocks
    blocks = loop.getBasicBlocks();
    while (blocks.hasMoreElements()) {
        BasicBlock block = blocks.nextElement();
        BasicBlock copy = originalToCloneBBMap.get(block);
        Enumeration<BasicBlock> outs = block.getOutNodes();
        while (outs.hasMoreElements()) {
            BasicBlock out = outs.nextElement();
            if (originalToCloneBBMap.containsKey(out)) {
                copy.redirectOuts(out, originalToCloneBBMap.get(out), ir);
            }
        }
    }
    // Fix up phis
    blocks = loop.getBasicBlocks();
    while (blocks.hasMoreElements()) {
        BasicBlock block = blocks.nextElement();
        BasicBlock copy = originalToCloneBBMap.get(block);
        IREnumeration.AllInstructionsEnum instructions = new IREnumeration.AllInstructionsEnum(ir, copy);
        while (instructions.hasMoreElements()) {
            Instruction instruction = instructions.nextElement();
            if (Phi.conforms(instruction)) {
                for (int i = 0; i < Phi.getNumberOfValues(instruction); i++) {
                    BasicBlock phi_predecessor = Phi.getPred(instruction, i).block;
                    if (originalToCloneBBMap.containsKey(phi_predecessor)) {
                        Phi.setPred(instruction, i, new BasicBlockOperand(originalToCloneBBMap.get(phi_predecessor)));
                    } else {
                        dumpIR(ir, "Error when optimising" + ir.getMethod());
                        throw new Error("There's > 1 route to this phi node " + instruction + " from outside the loop: " + phi_predecessor);
                    }
                }
            }
        }
    }
    return originalToCloneBBMap;
}

Example 30 with Operand

use of org.jikesrvm.compilers.opt.ir.operand.Operand in project JikesRVM by JikesRVM.

the class LoopVersioning method fixUpPhiPredecessors.

/**
 * When phi nodes were generated the basic blocks weren't known for
 * the predecessors, fix this up now. (It may also not be possible
 * to reach the unoptimized loop any more)
 *
 * @param phiInstructions a list of phi nodes
 * @param unoptimizedLoopExit the exit block of the unoptimized loop.
 *  This may be {@code null} if the unoptimized loop is no longer reachable.
 * @param optimizedLoopExit the exit block of the optimized loop
 */
private void fixUpPhiPredecessors(ArrayList<Instruction> phiInstructions, BasicBlock unoptimizedLoopExit, BasicBlock optimizedLoopExit) {
    if (unoptimizedLoopExit != null) {
        for (Instruction instruction : phiInstructions) {
            Phi.setPred(instruction, OPTIMIZED_LOOP_OPERAND, new BasicBlockOperand(optimizedLoopExit));
            Phi.setPred(instruction, UNOPTIMIZED_LOOP_OPERAND, new BasicBlockOperand(unoptimizedLoopExit));
        }
    } else {
        for (Instruction instruction : phiInstructions) {
            Operand operand = Phi.getValue(instruction, OPTIMIZED_LOOP_OPERAND);
            Phi.resizeNumberOfPreds(instruction, 1);
            Phi.resizeNumberOfValues(instruction, 1);
            Phi.setValue(instruction, OPTIMIZED_LOOP_OPERAND, operand);
            Phi.setPred(instruction, OPTIMIZED_LOOP_OPERAND, new BasicBlockOperand(optimizedLoopExit));
        }
    }
}