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Refactor instruction prefixes #14

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Refactor instruction prefixes #14

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4cd6796
Renamed InstructionPrefix -> LegacyPrefix
May 9, 2026
c19bbde
Added new interface InstructionPrefix
May 9, 2026
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30 changes: 15 additions & 15 deletions id/src/main/java/com/ledmington/cpu/InstructionDecoder.java
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Original file line number Diff line number Diff line change
Expand Up @@ -45,7 +45,7 @@
import com.ledmington.cpu.x86.IndirectOperandBuilder;
import com.ledmington.cpu.x86.Instruction;
import com.ledmington.cpu.x86.InstructionBuilder;
import com.ledmington.cpu.x86.InstructionPrefix;
import com.ledmington.cpu.x86.LegacyPrefix;
import com.ledmington.cpu.x86.MaskRegister;
import com.ledmington.cpu.x86.ModRM;
import com.ledmington.cpu.x86.NullRegister;
Expand Down Expand Up @@ -144,7 +144,7 @@ public static Instruction fromIntelSyntax(final String input) {
String opcodeString = readUntilWhitespace(it);
if ("lock".equals(opcodeString) || "rep".equals(opcodeString) || "repnz".equals(opcodeString)) {
final String finalOpcodeString = opcodeString;
ib.prefix(Arrays.stream(InstructionPrefix.values())
ib.prefix(Arrays.stream(LegacyPrefix.values())
.filter(p -> p.name().toLowerCase(Locale.US).equals(finalOpcodeString))
.findAny()
.orElseThrow());
Expand Down Expand Up @@ -599,7 +599,7 @@ yield isIndirectOperandNeeded(modrm)
!pref.hasAddressSizeOverridePrefix(),
pref.rex().hasModRMRMExtension(),
pref.hasOperandSizeOverridePrefix()));
if (pref.p1().isPresent() && pref.p1().orElseThrow() == InstructionPrefix.REPNZ) {
if (pref.p1().isPresent() && pref.p1().orElseThrow() == LegacyPrefix.REPNZ) {
ib.opcode(Opcode.BND_JMP);
} else {
ib.opcode(Opcode.JMP);
Expand Down Expand Up @@ -1356,7 +1356,7 @@ private static Instruction parse2BytesOpcode(
yield Instruction.builder().opcode(Opcode.ENDBR64).build();
} else if (x == (byte) 0xfb) {
yield Instruction.builder().opcode(Opcode.ENDBR32).build();
} else if (pref.p1().isPresent() && pref.p1().orElseThrow() == InstructionPrefix.REP) {
} else if (pref.p1().isPresent() && pref.p1().orElseThrow() == LegacyPrefix.REP) {
final ModRM modrm = new ModRM(x);
yield Instruction.builder()
.opcode(Opcode.RDSSPQ)
Expand Down Expand Up @@ -1515,7 +1515,7 @@ private static Instruction parse2BytesOpcode(
}
case BSF_OPCODE -> {
final ModRM modrm = modrm(b);
final boolean hasRepPrefix = pref.p1().isPresent() && pref.p1().orElseThrow() == InstructionPrefix.REP;
final boolean hasRepPrefix = pref.p1().isPresent() && pref.p1().orElseThrow() == LegacyPrefix.REP;
yield Instruction.builder()
.opcode(hasRepPrefix ? Opcode.TZCNT : Opcode.BSF)
.op(Registers.fromCode(
Expand Down Expand Up @@ -1642,7 +1642,7 @@ yield new GeneralInstruction(
final byte r1 = getByteFromReg(pref.rex(), modrm);
final byte r2 = getByteFromRM(pref, modrm);
final boolean movdqa = pref.hasOperandSizeOverridePrefix();
final boolean movdqu = pref.p1().isPresent() && pref.p1().orElseThrow() == InstructionPrefix.REP;
final boolean movdqu = pref.p1().isPresent() && pref.p1().orElseThrow() == LegacyPrefix.REP;
yield Instruction.builder()
.opcode(movdqa ? Opcode.MOVDQA : (movdqu ? Opcode.MOVDQU : Opcode.MOVQ))
.op((movdqa || movdqu) ? RegisterXMM.fromByte(r1) : RegisterMMX.fromByte(modrm.reg()))
Expand Down Expand Up @@ -2015,15 +2015,15 @@ yield new GeneralInstruction(
final ModRM modrm = modrm(b);
final InstructionBuilder ib = Instruction.builder();
ib.op(RegisterXMM.fromByte(getByteFromReg(pref.rex(), modrm)));
if (pref.p1().isPresent() && pref.p1().orElseThrow() == InstructionPrefix.REP) {
if (pref.p1().isPresent() && pref.p1().orElseThrow() == LegacyPrefix.REP) {
ib.opcode(Opcode.DIVSS)
.op(
isIndirectOperandNeeded(modrm)
? parseIndirectOperand(b, pref, modrm)
.pointer(PointerSize.DWORD_PTR)
.build()
: RegisterXMM.fromByte(getByteFromRM(pref, modrm)));
} else if (pref.p1().isPresent() && pref.p1().orElseThrow() == InstructionPrefix.REPNZ) {
} else if (pref.p1().isPresent() && pref.p1().orElseThrow() == LegacyPrefix.REPNZ) {
ib.opcode(Opcode.DIVSD)
.op(
isIndirectOperandNeeded(modrm)
Expand Down Expand Up @@ -2196,7 +2196,7 @@ yield new GeneralInstruction(
case MOVSD_OPCODE -> {
final ModRM modrm = modrm(b);
final boolean hasRepnePrefix =
pref.p1().isPresent() && pref.p1().orElseThrow() == InstructionPrefix.REPNZ;
pref.p1().isPresent() && pref.p1().orElseThrow() == LegacyPrefix.REPNZ;
yield Instruction.builder()
.opcode(hasRepnePrefix ? Opcode.MOVSD : Opcode.MOVUPS)
.op(RegisterXMM.fromByte(getByteFromReg(pref.rex(), modrm)))
Expand Down Expand Up @@ -2431,7 +2431,7 @@ private static Instruction parseExtendedOpcodeGroup9(
};
}

if (pref.p1().isPresent() && pref.p1().orElseThrow() == InstructionPrefix.REP) {
if (pref.p1().isPresent() && pref.p1().orElseThrow() == LegacyPrefix.REP) {
notImplemented();
}

Expand Down Expand Up @@ -4415,7 +4415,7 @@ private static void invalidValue() {
}

private static Prefixes parsePrefixes(final ReadOnlyByteBuffer b) {
Optional<InstructionPrefix> p1 = Optional.empty(); // Legacy Prefix Group 1
Optional<LegacyPrefix> p1 = Optional.empty(); // Legacy Prefix Group 1
Optional<Byte> p2 = Optional.empty(); // Legacy Prefix Group 2
boolean hasOperandSizeOverridePrefix = false;
boolean hasAddressSizeOverridePrefix = false;
Expand All @@ -4426,7 +4426,7 @@ private static Prefixes parsePrefixes(final ReadOnlyByteBuffer b) {
final byte x = b.read1();

if (isLegacyPrefixGroup1(x)) {
p1 = Optional.of(InstructionPrefix.fromByte(x));
p1 = Optional.of(LegacyPrefix.fromByte(x));
} else if (isLegacyPrefixGroup2(x)) {
p2 = Optional.of(x);
} else if (isOperandSizeOverridePrefix(x)) {
Expand Down Expand Up @@ -4662,9 +4662,9 @@ private static void notImplemented() {
}

private static boolean isLegacyPrefixGroup1(final byte prefix) {
return prefix == InstructionPrefix.LOCK.getCode()
|| prefix == InstructionPrefix.REPNZ.getCode()
|| prefix == InstructionPrefix.REP.getCode();
return prefix == LegacyPrefix.LOCK.getCode()
|| prefix == LegacyPrefix.REPNZ.getCode()
|| prefix == LegacyPrefix.REP.getCode();
}

private static boolean isLegacyPrefixGroup2(final byte prefix) {
Expand Down
8 changes: 4 additions & 4 deletions id/src/main/java/com/ledmington/cpu/InstructionEncoder.java
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Original file line number Diff line number Diff line change
Expand Up @@ -33,7 +33,7 @@
import com.ledmington.cpu.x86.Immediate;
import com.ledmington.cpu.x86.IndirectOperand;
import com.ledmington.cpu.x86.Instruction;
import com.ledmington.cpu.x86.InstructionPrefix;
import com.ledmington.cpu.x86.LegacyPrefix;
import com.ledmington.cpu.x86.MaskRegister;
import com.ledmington.cpu.x86.Opcode;
import com.ledmington.cpu.x86.Operand;
Expand Down Expand Up @@ -330,7 +330,7 @@ private static void encodePrefixes(final WriteOnlyByteBuffer wb, final Instructi
wb.write(OPERAND_SIZE_OVERRIDE_PREFIX);
}
if (inst.hasLockPrefix()) {
wb.write(InstructionPrefix.LOCK.getCode());
wb.write(LegacyPrefix.LOCK.getCode());
}
if (inst.hasRepPrefix()
|| (inst.opcode() == Opcode.RDSSPQ
Expand All @@ -341,7 +341,7 @@ private static void encodePrefixes(final WriteOnlyByteBuffer wb, final Instructi
|| (((inst.opcode() == Opcode.MOVQ || inst.opcode() == Opcode.MOVDQU)
&& isFirstXMM(inst)
&& isSecondM(inst)))) {
wb.write(InstructionPrefix.REP.getCode());
wb.write(LegacyPrefix.REP.getCode());
}
if (inst.hasRepnzPrefix()
|| ((inst.opcode() == Opcode.MOVSD && isFirstXMM(inst) && isSecondM(inst))
Expand All @@ -350,7 +350,7 @@ && isSecondM(inst)))) {
|| (inst.opcode() == Opcode.ADDSD)
|| (inst.opcode() == Opcode.LDDQU)
|| (inst.opcode() == Opcode.BND_JMP))) {
wb.write(InstructionPrefix.REPNZ.getCode());
wb.write(LegacyPrefix.REPNZ.getCode());
}

// TODO: maybe refactor this into 'checkRequiredPrefix'?
Expand Down
2 changes: 1 addition & 1 deletion id/src/main/java/com/ledmington/cpu/x86/EvexPrefix.java
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Expand Up @@ -22,7 +22,7 @@

/** The extended VEX prefix (EVEX): 0x62 + 3 bytes. */
@SuppressWarnings("PMD.UnusedPrivateField")
public final class EvexPrefix {
public final class EvexPrefix implements InstructionPrefix {

private final boolean r;
private final boolean x;
Expand Down
17 changes: 7 additions & 10 deletions id/src/main/java/com/ledmington/cpu/x86/GeneralInstruction.java
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Expand Up @@ -22,7 +22,7 @@
/** Most general implementation of an x86 instruction. */
public final class GeneralInstruction implements Instruction {

private final InstructionPrefix prefix;
private final LegacyPrefix prefix;
private final Opcode code;
private final MaskRegister destinationMask;
private final boolean destinationMaskZero;
Expand All @@ -32,7 +32,7 @@ public final class GeneralInstruction implements Instruction {
private final Operand op4;

/* default */ GeneralInstruction(
final InstructionPrefix prefix,
final LegacyPrefix prefix,
final Opcode opcode,
final MaskRegister destinationMask,
final boolean destinationMaskZero,
Expand Down Expand Up @@ -73,10 +73,7 @@ public final class GeneralInstruction implements Instruction {
* @param secondOperand The second operand of the Instruction.
*/
public GeneralInstruction(
final InstructionPrefix prefix,
final Opcode opcode,
final Operand firstOperand,
final Operand secondOperand) {
final LegacyPrefix prefix, final Opcode opcode, final Operand firstOperand, final Operand secondOperand) {
this(prefix, opcode, null, false, firstOperand, secondOperand, null, null);
}

Expand All @@ -103,7 +100,7 @@ public GeneralInstruction(
* @param thirdOperand The third operand of the Instruction.
*/
public GeneralInstruction(
final InstructionPrefix prefix,
final LegacyPrefix prefix,
final Opcode opcode,
final Operand firstOperand,
final Operand secondOperand,
Expand Down Expand Up @@ -147,7 +144,7 @@ public GeneralInstruction(final Opcode opcode, final Operand firstOperand, final
* @param opcode The opcode of the Instruction.
* @param firstOperand The first operand of the Instruction.
*/
public GeneralInstruction(final InstructionPrefix prefix, final Opcode opcode, final Operand firstOperand) {
public GeneralInstruction(final LegacyPrefix prefix, final Opcode opcode, final Operand firstOperand) {
this(prefix, opcode, null, false, firstOperand, null, null, null);
}

Expand All @@ -157,7 +154,7 @@ public GeneralInstruction(final InstructionPrefix prefix, final Opcode opcode, f
* @param prefix The prefix of the Instruction.
* @param opcode The opcode of the Instruction.
*/
public GeneralInstruction(final InstructionPrefix prefix, final Opcode opcode) {
public GeneralInstruction(final LegacyPrefix prefix, final Opcode opcode) {
this(prefix, opcode, null, false, null, null, null, null);
}

Expand Down Expand Up @@ -186,7 +183,7 @@ public boolean hasPrefix() {
}

@Override
public InstructionPrefix getPrefix() {
public LegacyPrefix getPrefix() {
if (!hasPrefix()) {
throw new IllegalArgumentException("No prefix.");
}
Expand Down
8 changes: 4 additions & 4 deletions id/src/main/java/com/ledmington/cpu/x86/Instruction.java
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Expand Up @@ -138,15 +138,15 @@ default Operand operand(final int operandIndex) {
*
* @return The prefix of this instruction.
*/
InstructionPrefix getPrefix();
LegacyPrefix getPrefix();

/**
* Checks whether this instruction has a LOCK prefix.
*
* @return True if this instruction has a LOCK prefix, false otherwise.
*/
default boolean hasLockPrefix() {
return hasPrefix() && getPrefix() == InstructionPrefix.LOCK;
return hasPrefix() && getPrefix() == LegacyPrefix.LOCK;
}

/**
Expand All @@ -155,7 +155,7 @@ default boolean hasLockPrefix() {
* @return True if this instruction has a REP prefix, false otherwise.
*/
default boolean hasRepPrefix() {
return hasPrefix() && getPrefix() == InstructionPrefix.REP;
return hasPrefix() && getPrefix() == LegacyPrefix.REP;
}

/**
Expand All @@ -164,7 +164,7 @@ default boolean hasRepPrefix() {
* @return True if this instruction has a REPNZ prefix, false otherwise.
*/
default boolean hasRepnzPrefix() {
return hasPrefix() && getPrefix() == InstructionPrefix.REPNZ;
return hasPrefix() && getPrefix() == LegacyPrefix.REPNZ;
}

/**
Expand Down
4 changes: 2 additions & 2 deletions id/src/main/java/com/ledmington/cpu/x86/InstructionBuilder.java
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Expand Up @@ -24,7 +24,7 @@
/** A builder for constructing {@link Instruction} objects. */
public final class InstructionBuilder {

private InstructionPrefix prefix = null;
private LegacyPrefix prefix = null;
private Opcode opcode = null;
private MaskRegister destinationMask = null;
private boolean destinationMaskZero = false;
Expand All @@ -49,7 +49,7 @@ private void assertNotBuilt() {
* @param prefix The prefix to set.
* @return This builder.
*/
public InstructionBuilder prefix(final InstructionPrefix prefix) {
public InstructionBuilder prefix(final LegacyPrefix prefix) {
assertNotBuilt();
if (this.prefix != null) {
throw new IllegalArgumentException("Cannot set prefix twice.");
Expand Down
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