Examples with FieldInstruction org.apache.bcel.generic.FieldInstruction used on opensource projects

Example 6 with FieldInstruction

use of org.apache.bcel.generic.FieldInstruction in project jop by jop-devel.

the class SimpleInliner method analyzeInvokee.

/**
     * @param cs the callstring from the invoker to the invoke to inline (if recursive). Used to check DFA results.
     * @param invokee the invoked method to analyze
     * @param inlineData the map to populate with the parameters and the instructions to inline.
     * @return true if inlining is possible
     */
private boolean analyzeInvokee(CallString cs, MethodInfo invokee, InlineData inlineData) {
    // we allow loading of parameters, loading of constants, some instruction, and a return
    ValueMapAnalysis values = new ValueMapAnalysis(invokee);
    values.loadParameters();
    InstructionList il = invokee.getCode().getInstructionList(true, false);
    InstructionHandle ih = il.getStart();
    // we should at least have a return instruction, so even for empty methods we should fall through
    // generate the parameter mapping
    int count = 0;
    while (true) {
        Instruction instruction = ih.getInstruction();
        if (instruction instanceof PushInstruction || instruction instanceof NOP) {
            values.transfer(instruction);
            ih = ih.getNext();
            count++;
        } else {
            break;
        }
    }
    // store the mapping
    for (ValueInfo value : values.getValueTable().getStack()) {
        inlineData.addParam(value);
    }
    inlineData.setInlineStart(count);
    // if we do not need an NP check, we can also inline code which does not throw an exception in the same way
    boolean needsNPCheck = helper.needsNullpointerCheck(cs, invokee, false);
    boolean hasNPCheck = false;
    // we allow up to 5 instructions and one return before assuming that the resulting code will be too large
    for (int i = 0; i < 6; i++) {
        // now lets see what we have here as non-push instructions
        Instruction instruction = ih.getInstruction();
        if (instruction instanceof InvokeInstruction) {
            if (inlineData.getInvokeSite() != null) {
                // only inline at most one invoke
                return false;
            }
            InvokeSite is = invokee.getCode().getInvokeSite(ih);
            inlineData.setInvokeSite(is);
            hasNPCheck |= !is.isInvokeStatic();
        } else if (instruction instanceof FieldInstruction) {
            if (instruction instanceof GETFIELD) {
                hasNPCheck |= values.getValueTable().top().isThisReference();
            }
            if (instruction instanceof PUTFIELD) {
                int down = values.getValueTable().top().isContinued() ? 2 : 1;
                hasNPCheck |= values.getValueTable().top(down).isThisReference();
            }
        } else if (instruction instanceof ArithmeticInstruction || instruction instanceof ConversionInstruction || instruction instanceof StackInstruction || instruction instanceof LDC || instruction instanceof LDC2_W || instruction instanceof ARRAYLENGTH || instruction instanceof CHECKCAST || instruction instanceof NOP) {
        // nothing to do, just copy them
        } else if (instruction instanceof ReturnInstruction) {
            if (needsNPCheck && !hasNPCheck) {
                // We were nearly finished.. but NP check test failed
                this.requiresNPCheck++;
                if (logger.isTraceEnabled()) {
                    logger.trace("Not inlining " + invokee + " because it requires a NP check.");
                }
                return false;
            }
            // else we need to add pop instructions
            if (instruction instanceof RETURN) {
                // we do not return anything, so we must empty the stack
                while (values.getValueTable().getStackSize() > 0) {
                    Instruction pop;
                    if (values.getValueTable().top().isContinued()) {
                        pop = new POP2();
                    } else {
                        pop = new POP();
                    }
                    inlineData.addEpilogue(pop);
                    values.transfer(pop);
                }
                return true;
            } else {
                Type type = ((ReturnInstruction) instruction).getType();
                // javac anyway)
                return values.getValueTable().getStackSize() == type.getSize();
            }
        } else {
            // if we encounter an instruction which we do not handle, we do not inline
            unhandledInstructions++;
            if (logger.isTraceEnabled()) {
                logger.trace("Not inlining " + invokee + " because of unhandled instruction " + instruction.toString(invokee.getClassInfo().getConstantPoolGen().getConstantPool()));
            }
            return false;
        }
        // update the stack map since we need it to handle RETURN
        values.transfer(instruction);
        ih = ih.getNext();
    }
    // too many instructions, do not inline
    return false;
}

Example 7 with FieldInstruction

use of org.apache.bcel.generic.FieldInstruction in project jop by jop-devel.

the class ObjectCacheAnalysis method extractAccessesAndCosts.

/** Traverse vertex set.
	 * <p>Add vertex to access set of referenced addresses
	 * For references whose type cannot be fully resolved, add a
	 * cost of 1.</p>
	 * <p>FIXME: We should deal with subtyping (or better use storage based alias-analysis)</p>
	 *
	 * @param nodes
	 * @param usedRefs the results of the local points-to analysis, or {@code null} for always miss costs
	 * @param costModel
	 */
private AccessCostInfo extractAccessesAndCosts(Iterable<SuperGraphNode> nodes, LocalPointsToResult usedRefs, ObjectCacheCostModel costModel) {
    AccessCostInfo aci = new AccessCostInfo();
    for (SuperGraphNode node : nodes) {
        /* Compute cost for basic block */
        BasicBlock bb = node.getCFGNode().getBasicBlock();
        if (bb == null)
            continue;
        long bypassCost = 0;
        long alwaysMissCost = 0;
        CallString cs = node.getContextCFG().getCallString();
        for (InstructionHandle ih : bb.getInstructions()) {
            String handleType = getHandleType(project, node.getCfg(), ih);
            if (handleType == null)
                continue;
            /* No getfield/handle access */
            int fieldIndex = getFieldIndex(project, node.getCfg(), ih);
            int blockIndex = getBlockIndex(fieldIndex);
            if (fieldIndex > this.maxCachedFieldIndex) {
                bypassCost += costModel.getFieldAccessCostBypass();
                continue;
            }
            BoundedSet<SymbolicAddress> refs = null;
            if (usedRefs != null) {
                if (!usedRefs.containsKey(ih)) {
                    usedRefs = null;
                    WCETTool.logger.error("No DFA results for: " + ih.getInstruction() + " with field " + ((FieldInstruction) ih.getInstruction()).getFieldName(bb.cpg()));
                } else {
                    refs = usedRefs.get(ih, cs);
                    if (refs.isSaturated())
                        refs = null;
                }
            }
            if (refs == null) {
                alwaysMissCost += costModel.getReplaceLineCost() + costModel.getLoadCacheBlockCost();
            } else {
                for (SymbolicAddress ref : refs.getSet()) {
                    aci.addRefAccess(ref, node);
                    aci.addBlockAccess(ref.accessArray(blockIndex), node);
                    // Handle getfield_long / getfield_double
                    if (getCachedType(project, node.getCfg(), ih) == Type.LONG || getCachedType(project, node.getCfg(), ih) == Type.DOUBLE) {
                        if (blockIndex + 1 > this.maxCachedFieldIndex) {
                            bypassCost += costModel.getFieldAccessCostBypass();
                        } else {
                            aci.addBlockAccess(ref.accessArray(blockIndex + 1), node);
                        }
                    }
                }
            }
        }
        aci.putBypassCost(node, bypassCost);
        aci.putStaticCost(node, bypassCost + alwaysMissCost);
    }
    return aci;
}

Example 8 with FieldInstruction

use of org.apache.bcel.generic.FieldInstruction in project jop by jop-devel.

the class ObjectCacheAnalysis method getFieldIndex.

/**
	 * @return the index of the field accessed by the instruction, or 0 if the instruction
	 * does not access a field
	 */
private static int getFieldIndex(WCETTool p, ControlFlowGraph cfg, InstructionHandle ih) {
    ConstantPoolGen constPool = cfg.getMethodInfo().getConstantPoolGen();
    Instruction instr = ih.getInstruction();
    if (instr instanceof FieldInstruction) {
        FieldInstruction fieldInstr = (FieldInstruction) instr;
        ReferenceType refType = fieldInstr.getReferenceType(constPool);
        if (!(refType instanceof ObjectType)) {
            throw new RuntimeException("getFieldIndex(): Unsupported object kind: " + refType.getClass());
        }
        ObjectType objType = (ObjectType) refType;
        String klassName = objType.getClassName();
        String fieldName = fieldInstr.getFieldName(constPool);
        String fieldSig = fieldInstr.getSignature(constPool);
        return p.getLinkerInfo().getFieldIndex(klassName, fieldName + fieldSig);
    } else {
        return 0;
    }
}