org.jikesrvm.compilers.opt.inlining

Class DefaultInlineOracle

java.lang.Object

org.jikesrvm.compilers.opt.inlining.InlineTools

org.jikesrvm.compilers.opt.inlining.DefaultInlineOracle

All Implemented Interfaces:

InlineOracle

public final class DefaultInlineOracle
extends InlineTools
implements InlineOracle

The default inlining oracle used by the optimizing compiler. The basic strategy is as follows:

1. Always inline trivial methods that can be inlined without a guard
2. At O1 and greater use a mix of profile information and static heuristics to inline larger methods and methods that require guards.

Constructor Summary

Constructors

Constructor and Description
DefaultInlineOracle()

Method Summary

Modifier and Type	Method and Description
private byte	chooseGuard(RVMMethod caller, RVMMethod singleImpl, RVMMethod callee, CompilationState state, boolean codePatchSupported) Logic to select the appropriate guarding mechanism for the edge from caller to callee according to the controlling OptOptions.
private int	inliningActionCost(int inlinedBodyEstimate, boolean needsGuard, boolean preEx, OptOptions opts) Estimate the expected cost of the inlining action (includes both the inline body and the guard/off-branch code).
InlineDecision	shouldInline(CompilationState state) Should we inline a particular call site?

Methods inherited from class org.jikesrvm.compilers.opt.inlining.InlineTools

hasBody, hasInlinePragma, hasNoInlinePragma, implementsInterface, inlinedSizeEstimate, isCurrentlyFinal, isForbiddenSpeculation, needsGuard

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DefaultInlineOracle

public DefaultInlineOracle()

Method Detail

shouldInline

public InlineDecision shouldInline(CompilationState state)

Description copied from interface: InlineOracle

Should we inline a particular call site?

Specified by:

shouldInline in interface InlineOracle

Parameters:

state - information needed to make the inlining decision

Returns:

an InlineDecision with the result

chooseGuard

private byte chooseGuard(RVMMethod caller,
                         RVMMethod singleImpl,
                         RVMMethod callee,
                         CompilationState state,
                         boolean codePatchSupported)

Logic to select the appropriate guarding mechanism for the edge from caller to callee according to the controlling OptOptions. If we are using IG_CODE_PATCH, then this method also records the required dependency. Precondition: lock on RVMClass.classLoadListener is held.

Parameters:

caller - The caller method

singleImpl - the method implementation that will be protected by the guard

callee - The callee method

state - compilation state at this point

codePatchSupported - Can we use code patching at this call site?

Returns:

the chosen guard

inliningActionCost

private int inliningActionCost(int inlinedBodyEstimate,
                               boolean needsGuard,
                               boolean preEx,
                               OptOptions opts)

Estimate the expected cost of the inlining action (includes both the inline body and the guard/off-branch code).

Parameters:

inlinedBodyEstimate - size estimate for inlined body

needsGuard - is it going to be a guarded inline?

preEx - can preEx inlining be used to avoid the guard?

opts - controlling options object

Returns:

the estimated cost of the inlining action