MOS6502Snapshot.java

package com.rox.cpu.mos6502;

/**
 * Everything needed to put a {@link MOS6502} back exactly where it was at an instruction boundary (see
 * {@link MOS6502#snapshot()}) - plain values only, so a save format never needs the mutable, partly
 * package-private {@link MOS6502Environment} itself. {@code ir}/{@code adl}/{@code adh} are just the
 * last instruction's leftovers at a boundary, but are kept so a restore is exact rather than "close enough".
 */
public record MOS6502Snapshot(int pc, int a, int x, int y, int stackPointer, int ir, int adl, int adh,
                              boolean negative, boolean signedOverflow, boolean breakFlag, boolean decimal,
                              boolean interruptDisable, boolean zero, boolean carry,
                              boolean irqLineAsserted, boolean nmiPending) {
    private static final int BYTE = 0xFF;
    private static final int X_SHIFT = 8;
    private static final int Y_SHIFT = 16;
    private static final int SP_SHIFT = 24;
    private static final int N = 0x80;
    private static final int V = 0x40;
    private static final int B = 0x10;
    private static final int D = 0x08;
    private static final int I = 0x04;
    private static final int Z = 0x02;
    private static final int C = 0x01;
    private static final int IRQ_LINE = 0x100;
    private static final int NMI_PENDING = 0x200;

    /** A, X, Y and SP in one int - for recording every instruction without allocating. */
    public static int packRegisters(final int a, final int x, final int y, final int stackPointer){
        return (a & BYTE) | (x & BYTE) << X_SHIFT | (y & BYTE) << Y_SHIFT | (stackPointer & BYTE) << SP_SHIFT;
    }

    /** The status flags (as NV-BDIZC bits) plus the IRQ line and NMI latch, in one int. */
    public static int packFlags(final boolean negative, final boolean signedOverflow, final boolean breakFlag,
                                final boolean decimal, final boolean interruptDisable, final boolean zero,
                                final boolean carry, final boolean irqLineAsserted, final boolean nmiPending){
        return (negative ? N : 0) | (signedOverflow ? V : 0) | (breakFlag ? B : 0) | (decimal ? D : 0)
                | (interruptDisable ? I : 0) | (zero ? Z : 0) | (carry ? C : 0)
                | (irqLineAsserted ? IRQ_LINE : 0) | (nmiPending ? NMI_PENDING : 0);
    }

    /** Rebuilds a snapshot from {@link #packRegisters}/{@link #packFlags} - with no {@code ir}/{@code adl}/{@code adh}, which aren't recorded. */
    public static MOS6502Snapshot unpack(final int pc, final int registers, final int flags){
        return new MOS6502Snapshot(pc, registers & BYTE, registers >>> X_SHIFT & BYTE, registers >>> Y_SHIFT & BYTE,
                registers >>> SP_SHIFT & BYTE, 0, 0, 0,
                (flags & N) != 0, (flags & V) != 0, (flags & B) != 0, (flags & D) != 0, (flags & I) != 0,
                (flags & Z) != 0, (flags & C) != 0, (flags & IRQ_LINE) != 0, (flags & NMI_PENDING) != 0);
    }
}







Active mutators

CONDITIONALS_BOUNDARY
EMPTY_RETURNS
FALSE_RETURNS
INCREMENTS
INVERT_NEGS
MATH
NEGATE_CONDITIONALS
NULL_RETURNS
PRIMITIVE_RETURNS
TRUE_RETURNS
VOID_METHOD_CALLS

Tests examined

com.rox.cpu.mos6502.MOS6502SnapshotTest.[engine:jqwik]/[class:com.rox.cpu.mos6502.MOS6502SnapshotTest]/[property:packedRegistersAndFlagsUnpackToTheSameState(int, int, int, int, int, boolean, boolean, boolean, boolean, boolean, boolean, boolean, boolean, boolean)] (123 ms)
com.rox.debug.cpu.CpuStateTextTest.[engine:junit-jupiter]/[class:com.rox.debug.cpu.CpuStateTextTest]/[method:panelShowsWhenPaused()] (0 ms)
com.rox.debug.cpu.CpuStateTextTest.[engine:junit-jupiter]/[class:com.rox.debug.cpu.CpuStateTextTest]/[method:panelRunsTimeBottomToTopWithTheCurrentInstructionBetweenNextAndRecent()] (0 ms)
com.rox.debug.cpu.CpuStateTextTest.[engine:junit-jupiter]/[class:com.rox.debug.cpu.CpuStateTextTest]/[method:panelCanUseAStateTheCallerAlreadyRead()] (1 ms)
com.rox.debug.cpu.CpuTextHighlighterTest.[engine:junit-jupiter]/[class:com.rox.debug.cpu.CpuTextHighlighterTest]/[method:spansLineUpWithRealStateLines()] (0 ms)
com.rox.debug.cpu.InstructionTraceTest.[engine:junit-jupiter]/[class:com.rox.debug.cpu.InstructionTraceTest]/[method:historyRecordsTheStateEachInstructionStartedWith()] (1 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:stepInstructionFromMidInstructionJustFinishesIt()] (0 ms)
com.rox.NesCpuDebugSourceTest.[engine:junit-jupiter]/[class:com.rox.NesCpuDebugSourceTest]/[method:stepInstructionStepsTheNes()] (0 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:stepInstructionCompletesAStepTakingExactlyTheCap()] (7 ms)
com.rox.NesCpuDebugSourceTest.[engine:junit-jupiter]/[class:com.rox.NesCpuDebugSourceTest]/[method:stepCyclesStepsTheNes()] (0 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:vblankNmiDoesNotFireBeforeTheRealVblankEdge()] (1 ms)
com.rox.NesMemoryDebugSourceTest.[engine:junit-jupiter]/[class:com.rox.NesMemoryDebugSourceTest]/[method:peekReadsRamAsTheProgramLeftIt()] (0 ms)
com.rox.NesMemoryDebugSourceTest.[engine:junit-jupiter]/[class:com.rox.NesMemoryDebugSourceTest]/[method:peekReadsRamMirrorsCartridgeAndRegisterPlaceholder()] (0 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:pauseFinishesTheInstructionTheCpuWasPartWayThroughBeforeSilencingAudio()] (0 ms)
com.rox.NesMemoryDebugSourceTest.[engine:junit-jupiter]/[class:com.rox.NesMemoryDebugSourceTest]/[method:eachPeekIsAConsistentCopyTakenWhenAskedFor()] (0 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:stepInstructionRunsExactlyOneInstruction()] (0 ms)
com.rox.NesCpuDebugSourceTest.[engine:junit-jupiter]/[class:com.rox.NesCpuDebugSourceTest]/[method:instructionCountGoesUpByOnePerInstructionStep()] (0 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:stepInstructionIncludesAnOamDmaStallThatFollows()] (1 ms)
com.rox.NesCpuDebugSourceTest.[engine:junit-jupiter]/[class:com.rox.NesCpuDebugSourceTest]/[method:stateIsTheCpusLiveState()] (1 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:instructionTraceRecordsEachInstructionOnceEvenAcrossAnOamDmaStall()] (4 ms)
com.rox.NesCpuDebugSourceTest.[engine:junit-jupiter]/[class:com.rox.NesCpuDebugSourceTest]/[method:upcomingInstructionsStartAtThePc()] (0 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:captureWithTheClockStoppedMidInstructionFinishesThatInstructionFirst()] (0 ms)
com.rox.NesCpuDebugSourceTest.[engine:junit-jupiter]/[class:com.rox.NesCpuDebugSourceTest]/[method:recentInstructionsAreHistoryOldestFirstWithoutTheOneAtThePc()] (2 ms)
com.rox.NesCpuDebugSourceTest.[engine:junit-jupiter]/[class:com.rox.NesCpuDebugSourceTest]/[method:historyCarriesEachInstructionsStartingStateAndTheCurrentOnesToo()] (0 ms)
com.rox.NesCpuDebugSourceTest.[engine:junit-jupiter]/[class:com.rox.NesCpuDebugSourceTest]/[method:midInstructionBothListsAreAnchoredOnTheInstructionInProgressNotThePc()] (1 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:stepFrameGivesUpRatherThanHangingIfNoFrameFinishes()] (16 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:tickRateMonitorSeesEveryClockTick()] (2 ms)
com.rox.NesLabelWatchTargetTest.[engine:junit-jupiter]/[class:com.rox.NesLabelWatchTargetTest]/[method:aWatchModelOverARealNesHoldsALockedLabelAgainstTheProgram()] (3 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:aLockHoldsAgainstTheGamesOwnWritesUntilUnlocked()] (4 ms)
com.rox.NesCpuDebugSourceTest.[engine:junit-jupiter]/[class:com.rox.NesCpuDebugSourceTest]/[method:stepFrameStepsTheNes()] (22 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:ramIsTheCpuRamTheProgramWrites()] (1 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:powerOnGracefullyHandlesInterruptionDuringTheWarmUpSleepItself()] (19 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:vblankNmiReachesTheCpusRealNmiLine()] (23 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:stepCyclesRunsExactlyThatManyCycles()] (21 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:dmcExhaustionIrqReachesTheCpusRealIrqLine()] (33 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:frameReadyPresentsTheFramebufferToVideoOutput()] (55 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:restoreRejectingAMalformedPartChangesNothing()] (48 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:frameReadyPollsAllFourConfiguredControllers()] (111 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:stepFrameRunsToTheNextPresentedFrameThenFinishesTheInstruction()] (181 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:restoredNesRunsInLockstepWithTheOriginal()] (140 ms)
com.rox.DebugCaptureTest.[engine:junit-jupiter]/[class:com.rox.DebugCaptureTest]/[method:flaggedIssueFolderRestoresIntoAFreshNes(java.nio.file.Path)] (153 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:powerOffDuringWarmUpPreventsAudioFromStartingAfterShutdown()] (302 ms)
com.rox.ApuTestRomIntegrationTest.[engine:junit-jupiter]/[class:com.rox.ApuTestRomIntegrationTest]/[test-template:reportsExpectedStatus(java.lang.String, int)]/[test-template-invocation:#8] (232 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:powerOnGracefullyHandlesInterruptionAfterAudioHasAlreadyStarted()] (318 ms)
com.rox.ApuTestRomIntegrationTest.[engine:junit-jupiter]/[class:com.rox.ApuTestRomIntegrationTest]/[test-template:reportsExpectedStatus(java.lang.String, int)]/[test-template-invocation:#6] (244 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:powerOffWhilePausedStillShutsDown()] (320 ms)
com.rox.ApuTestRomIntegrationTest.[engine:junit-jupiter]/[class:com.rox.ApuTestRomIntegrationTest]/[test-template:reportsExpectedStatus(java.lang.String, int)]/[test-template-invocation:#4] (251 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:powerOnLetsTheClockWarmUpBeforeStartingAudioOutput()] (336 ms)
com.rox.ApuTestRomIntegrationTest.[engine:junit-jupiter]/[class:com.rox.ApuTestRomIntegrationTest]/[test-template:reportsExpectedStatus(java.lang.String, int)]/[test-template-invocation:#7] (262 ms)
com.rox.ApuTestRomIntegrationTest.[engine:junit-jupiter]/[class:com.rox.ApuTestRomIntegrationTest]/[test-template:reportsExpectedStatus(java.lang.String, int)]/[test-template-invocation:#5] (267 ms)
com.rox.ApuTestRomIntegrationTest.[engine:junit-jupiter]/[class:com.rox.ApuTestRomIntegrationTest]/[test-template:reportsExpectedStatus(java.lang.String, int)]/[test-template-invocation:#3] (310 ms)
com.rox.ApuTestRomIntegrationTest.[engine:junit-jupiter]/[class:com.rox.ApuTestRomIntegrationTest]/[test-template:reportsExpectedStatus(java.lang.String, int)]/[test-template-invocation:#2] (324 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:captureAndRestoreAreRefusedWhileRunningButAllowedOncePaused()] (338 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:powerOffReturnsOnlyOnceTheClockHasStoppedTicking()] (418 ms)
com.rox.ApuTestRomIntegrationTest.[engine:junit-jupiter]/[class:com.rox.ApuTestRomIntegrationTest]/[test-template:reportsExpectedStatus(java.lang.String, int)]/[test-template-invocation:#1] (411 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:powerOnStartsAudioOutputRunsAndFeedsItSamplesUntilPoweredOff()] (530 ms)
com.rox.NESTest.[engine:junit-jupiter]/[class:com.rox.NESTest]/[method:pauseFreezesARunningNesAndResumeCarriesOn()] (563 ms)
com.rox.ApuTestRomIntegrationTest.[engine:junit-jupiter]/[class:com.rox.ApuTestRomIntegrationTest]/[method:combinedRomReportsExpectedStatus()] (2622 ms)
com.rox.debug.cpu.InstructionTraceTest.[engine:junit-jupiter]/[class:com.rox.debug.cpu.InstructionTraceTest]/[method:withoutStateSuppliersHistoryHasZeroedState()] (0 ms)
com.rox.debug.cpu.InstructionTraceTest.[engine:junit-jupiter]/[class:com.rox.debug.cpu.InstructionTraceTest]/[method:recordedBytesWrapAtTheTopOfTheAddressSpace()] (0 ms)
com.rox.debug.cpu.InstructionTraceTest.[engine:junit-jupiter]/[class:com.rox.debug.cpu.InstructionTraceTest]/[method:historyKeepsTheBytesThatRanEvenAfterTheAddressHoldsDifferentCode()] (0 ms)
com.rox.debug.cpu.InstructionTraceTest.[engine:junit-jupiter]/[class:com.rox.debug.cpu.InstructionTraceTest]/[method:recordsAllThreeBytesOfTheLongestInstructions()] (0 ms)
com.rox.debug.cpu.InstructionTraceTest.[engine:junit-jupiter]/[class:com.rox.debug.cpu.InstructionTraceTest]/[method:recentInstructionsAreOldestFirstAndMatchRecentAddresses()] (1 ms)
com.rox.debug.cpu.InstructionTraceTest.[engine:junit-jupiter]/[class:com.rox.debug.cpu.InstructionTraceTest]/[method:historyMatchesRecentInstructionsWhenTheBufferHasWrapped()] (1 ms)

Report generated by PIT 1.22.1

MOS6502Snapshot.java

Mutations

Active mutators

Tests examined