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

Example 11 with InstructionHandle

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

the class InlineHelper method checkCode.

/**
     * check the code of the invoked method if it contains instructions which prevent inlining.
     *
     * @param invoker the method into which the invokee will be inlined.
     * @param invokee the invoked method.
     * @return true if the code can be inlined and {@link #prepareInlining(MethodInfo, MethodInfo)} will succeed.
     */
private boolean checkCode(MethodInfo invoker, MethodInfo invokee) {
    MethodCode code = invokee.getCode();
    // Go through code, check for access to fields and invocations
    for (InstructionHandle ih : code.getInstructionList(true, false).getInstructionHandles()) {
        Instruction instr = ih.getInstruction();
        if (instr instanceof InvokeInstruction) {
            InvokeSite invokeSite = code.getInvokeSite(ih);
            MethodRef ref = invokeSite.getInvokeeRef();
            MethodInfo method = ref.getMethodInfo();
            if (method == null) {
                // TODO perform basic check on classnames if invoked method must already be public?
                return false;
            }
            // invokespecial is somewhat, well, special..
            if (invokeSite.isInvokeSpecial()) {
                if (checkInvokeSpecial(invoker, invokee, invokeSite, ref.getClassInfo(), method) == CheckResult.SKIP) {
                    return false;
                }
            } else {
                // check if fields need to be set to public
                if (checkNeedsPublic(invoker, invokee, ref.getClassInfo(), method) == CheckResult.SKIP) {
                    return false;
                }
            }
        } else if (instr instanceof FieldInstruction) {
            FieldRef ref = code.getFieldRef(ih);
            FieldInfo field = ref.getFieldInfo();
            if (field == null) {
                // TODO perform basic check on classnames if field is already public?
                return false;
            }
            // check if fields need to be set to public
            if (checkNeedsPublic(invoker, invokee, ref.getClassInfo(), field) == CheckResult.SKIP) {
                return false;
            }
        }
    }
    return true;
}

Example 12 with InstructionHandle

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

the class InlineHelper method prepareInlining.

/**
     * Prepare the invokee for inlining into the invokesite, by widening access restrictions or renaming
     * methods to prevent incorrect method resolving.
     * <p>
     * This may change the code of the invokee, so this needs to be done before inlining the code.
     * The CFG of the invokee will be removed.
     * </p><p>
     * This code assumes that {@link #canInline(CallString, InvokeSite, MethodInfo)} returned true for this invoke.
     * </p>
     *
     * @param invoker the method where the code will be inlined to.
     * @param invokee the method to inline.
     */
public void prepareInlining(MethodInfo invoker, MethodInfo invokee) {
    MethodCode code = invokee.getCode();
    InstructionList il = code.getInstructionList();
    for (InstructionHandle ih : il.getInstructionHandles()) {
        Instruction instr = ih.getInstruction();
        if (instr instanceof InvokeInstruction) {
            InvokeSite invokeSite = code.getInvokeSite(ih);
            MethodRef ref = invokeSite.getInvokeeRef();
            MethodInfo method = ref.getMethodInfo();
            // we already checked that everything can be resolved
            // nothing special to do for invokespecial here (checkInvokeSpecial only skips, no special return codes)
            // check what we need to do
            CheckResult rs = checkNeedsPublic(invoker, invokee, ref.getClassInfo(), method);
            if (rs == CheckResult.NEEDS_PUBLIC) {
                makePublic(method);
            }
            if (rs == CheckResult.NEEDS_PUBLIC_RENAME) {
                if (method.isPrivate()) {
                // TODO check the class for invokers, change to invokevirtual
                } else {
                // if the method is package visible, we need to rename all overriding methods
                // too (but not methods from subclasses in different packages which do not override this)
                // TODO update overriding methods
                // TODO need to update all possible call sites
                }
                makePublic(method);
                throw new AppInfoError("Implement me!");
            }
        } else if (instr instanceof FieldInstruction) {
            FieldRef ref = code.getFieldRef(ih);
            FieldInfo field = ref.getFieldInfo();
            // we already checked that everything can be resolved
            // check if fields need to be set to public
            CheckResult rs = checkNeedsPublic(invoker, invokee, ref.getClassInfo(), field);
            if (rs == CheckResult.NEEDS_PUBLIC) {
                makePublic(field);
            }
            if (rs == CheckResult.NEEDS_PUBLIC_RENAME) {
                throw new AppInfoError("Invalid returncode: renaming of fields not required");
            }
        }
    }
}

Example 13 with InstructionHandle

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

the class InlineHelper method needsNullpointerCheck.

/**
     * Check if an exception must be generated if the 'this' reference is null.
     * This test can return false if
     * <ul><li>There is no 'this' reference</li>
     * <li>The DFA analysis showed that the reference is never null</li>
     * <li>The inlined code will always generate an exception anyway</li>
     * <li>Generating checks has been disabled by configuration</li>
     * </ul>
     * <p>
     * The callstring does not need to start or to end at the method to optimize. However since the callstring is
     * used to check the DFA results if available, the callstring must match what the DFA expects, i.e. if
     * the DFA-results and -callstrings are updated during inlining, this callstring must not include inlined
     * invokes. Contrariwise if the DFA results are not updated during inline, the callstring must contain already
     * inlined invokes.
     * </p>
     *
     * @param callString The callstring including the invokesite of the invokee. The top invokesite does not need to
     *                   refer to an invoke instruction, and the referenced invoker method does not need to
     *                   be the method containing the invoke to inline (e.g. if the invoke to inline has
     *                   been inlined itself). However the callstring needs to match what the DFA expects.
     * @param invokee the devirtualized invokee.
     * @param analyzeCode if false, skip checking the code of the invokee.
     * @return true if a nullpointer check code should be generated.
     */
public boolean needsNullpointerCheck(CallString callString, MethodInfo invokee, boolean analyzeCode) {
    if (inlineConfig.skipNullpointerChecks())
        return false;
    InvokeSite invokeSite = callString.top();
    // check if we have a 'this' reference anyway
    if (invokeSite.isInvokeStatic() || invokeSite.isJVMCall()) {
        return false;
    }
    // TODO check the DFA results if available
    if (jcopter.useDFA()) {
    } else if ("<init>".equals(invokee.getShortName())) {
        // the NP check in this case (and hope that compilers for languages other than Java do the same..)
        return false;
    }
    if (!analyzeCode) {
        return true;
    }
    // check if the code will always throw an exception anyway (without producing any side effects before throwing)
    ValueMapAnalysis analysis = new ValueMapAnalysis(invokee);
    analysis.loadParameters();
    InstructionList list = invokee.getCode().getInstructionList(true, false);
    for (InstructionHandle ih : list.getInstructionHandles()) {
        Instruction instr = ih.getInstruction();
        if (instr instanceof ConstantPushInstruction || instr instanceof LocalVariableInstruction) {
            analysis.transfer(instr);
        } else if (instr instanceof GETFIELD || instr instanceof PUTFIELD || instr instanceof INVOKEVIRTUAL || instr instanceof INVOKEINTERFACE || instr instanceof INVOKESPECIAL) {
            int down = instr.consumeStack(invokee.getConstantPoolGen());
            ValueInfo value = analysis.getValueTable().top(down);
            // the same way as the inlined invoke
            if (value.isThisReference()) {
                return false;
            }
            break;
        } else {
            // we ignore all other instructions (for now..)
            break;
        }
    }
    return true;
}

Example 14 with InstructionHandle

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

the class WCAInvoker method updateWCEP.

private void updateWCEP() {
    if (!provideWCAExecCount)
        return;
    execCounts.clear();
    for (MethodInfo root : getWcaTargets()) {
        execCounts.put(root, 1L);
    }
    NodeVisitor<ExecutionContext> visitor = new NodeVisitor<ExecutionContext>() {

        @Override
        public boolean visitNode(ExecutionContext context) {
            MethodInfo method = context.getMethodInfo();
            MethodCode code = method.getCode();
            long ec = getExecCount(method);
            // skip methods which are not on the WCET path.. we can ship iterating over the childs too..
            if (ec == 0)
                return false;
            // iterate over all blocks in the CFG, find all invokes and add block execution counts to invokees
            ControlFlowGraph cfg = method.getCode().getControlFlowGraph(false);
            for (CFGNode node : cfg.getGraph().vertexSet()) {
                if (node instanceof InvokeNode) {
                    InvokeNode inv = (InvokeNode) node;
                    long ef = getExecFrequency(method, node);
                    for (MethodInfo invokee : inv.getImplementingMethods()) {
                        addExecCount(invokee, ec * ef);
                    }
                } else if (node instanceof BasicBlockNode) {
                    // check if we have a JVM invoke here (or an invoke not in a dedicated node..)
                    for (InstructionHandle ih : node.getBasicBlock().getInstructions()) {
                        if (!code.isInvokeSite(ih))
                            continue;
                        long ef = getExecFrequency(method, node);
                        for (MethodInfo invokee : method.getAppInfo().findImplementations(code.getInvokeSite(ih))) {
                            addExecCount(invokee, ec * ef);
                        }
                    }
                }
            }
            return true;
        }
    };
    TopologicalTraverser<ExecutionContext, ContextEdge> topOrder = new TopologicalTraverser<ExecutionContext, ContextEdge>(wcetTool.getCallGraph().getGraph(), visitor);
    topOrder.traverse();
}

Example 15 with InstructionHandle

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

the class SimpleInliner method analyzeCodeSize.

/**
     * Check if the resulting code will not be larger than the older code.
     * @param invokeSite the invokesite to inline.
     * @param invokee the invoked method.
     * @param inlineData the map to store the analyzer results
     * @return true if the new code will not violate any size constrains
     */
private boolean analyzeCodeSize(InvokeSite invokeSite, MethodInfo invokee, InlineData inlineData) {
    ProcessorModel pm = AppInfo.getSingleton().getProcessorModel();
    MethodInfo invoker = invokeSite.getInvoker();
    // delta = new prologue + inlined code + epilogue - old prologue - invokesite
    int delta = 0;
    InstructionHandle[] il = invokee.getCode().getInstructionList().getInstructionHandles();
    InstructionHandle ih = il[inlineData.getInlineStart()];
    while (ih != null) {
        Instruction instr = ih.getInstruction();
        if (instr instanceof ReturnInstruction) {
            break;
        }
        delta += pm.getNumberOfBytes(invokee, instr);
        ih = ih.getNext();
    }
    for (InstructionHandle instr : inlineData.getPrologue().getInstructionHandles()) {
        delta += pm.getNumberOfBytes(invoker, instr.getInstruction());
    }
    for (InstructionHandle instr : inlineData.getEpilogue().getInstructionHandles()) {
        delta += pm.getNumberOfBytes(invoker, instr.getInstruction());
    }
    ih = invokeSite.getInstructionHandle();
    for (int i = 0; i <= inlineData.getOldPrologueLength(); i++) {
        Instruction instr = ih.getInstruction();
        delta -= pm.getNumberOfBytes(invoker, instr);
        ih = ih.getPrev();
    }
    // TODO we could allow for some slack, especially if we decreased the codesize before..
    return delta <= 0;
}