static Address mapLimit(final int units, final int heads) {
// final int WORD_SIZE = ArchitecturalWord.getModel().bytesInWord();
final int WORD_SIZE = 4;
return baseAddress.plus(
Math.floorDiv(((units + heads + 1) * WORD_SIZE * 2) + (PAGE_SIZE - 1), PAGE_SIZE)
* PAGE_SIZE);
}
/**
* Low level copy of <code>len</code> elements from <code>src[srcPos]</code> to <code>dst[dstPos]
* </code>.
*
* <p>Assumption <code>src != dst || (srcPos >= dstPos)</code> and element size is 8 bytes.
*
* @param src the source array
* @param srcIdx index in the source array to begin copy
* @param dst the destination array
* @param dstIdx index in the destination array to being copy
* @param len number of array elements to copy
*/
@Inline
public static void arraycopy64Bit(Object src, int srcIdx, Object dst, int dstIdx, int len) {
Address srcPtr = VM_Magic.objectAsAddress(src).plus(srcIdx << LOG_BYTES_IN_DOUBLE);
Address dstPtr = VM_Magic.objectAsAddress(dst).plus(dstIdx << LOG_BYTES_IN_DOUBLE);
int copyBytes = len << LOG_BYTES_IN_DOUBLE;
if (USE_NATIVE && len > (NATIVE_THRESHOLD >> LOG_BYTES_IN_DOUBLE)) {
memcopy(dstPtr, srcPtr, copyBytes);
} else {
// The elements of long[] and double[] are always doubleword aligned
// therefore we can do 64 bit load/stores without worrying about alignment.
Address endPtr = srcPtr.plus(copyBytes);
while (srcPtr.LT(endPtr)) {
// We generate abysmal code on IA32 if we try to use the FP registers,
// so use the gprs instead even though it results in more instructions.
if (VM.BuildForIA32) {
dstPtr.store(srcPtr.loadInt());
dstPtr.store(srcPtr.loadInt(Offset.fromIntSignExtend(4)), Offset.fromIntSignExtend(4));
} else {
dstPtr.store(srcPtr.loadDouble());
}
srcPtr = srcPtr.plus(8);
dstPtr = dstPtr.plus(8);
}
}
}
private boolean acquireRecyclableLines(int bytes, int align, int offset) {
while (line < LINES_IN_BLOCK || acquireRecyclableBlock()) {
line = space.getNextAvailableLine(markTable, line);
if (line < LINES_IN_BLOCK) {
int endLine = space.getNextUnavailableLine(markTable, line);
cursor = recyclableBlock.plus(Extent.fromIntSignExtend(line << LOG_BYTES_IN_LINE));
limit = recyclableBlock.plus(Extent.fromIntSignExtend(endLine << LOG_BYTES_IN_LINE));
if (SANITY_CHECK_LINE_MARKS) {
Address tmp = cursor;
while (tmp.LT(limit)) {
if (tmp.loadByte() != (byte) 0) {
Log.write("cursor: ");
Log.writeln(cursor);
Log.write(" limit: ");
Log.writeln(limit);
Log.write("current: ");
Log.write(tmp);
Log.write(" value: ");
Log.write(tmp.loadByte());
Log.write(" line: ");
Log.write(line);
Log.write("endline: ");
Log.write(endLine);
Log.write(" chunk: ");
Log.write(Chunk.align(cursor));
Log.write(" hw: ");
Log.write(Chunk.getHighWater(Chunk.align(cursor)));
Log.writeln(" values: ");
Address tmp2 = cursor;
while (tmp2.LT(limit)) {
Log.write(tmp2.loadByte());
Log.write(" ");
}
Log.writeln();
}
VM.assertions._assert(tmp.loadByte() == (byte) 0);
tmp = tmp.plus(1);
}
}
if (VM.VERIFY_ASSERTIONS && bytes <= BYTES_IN_LINE) {
Address start = alignAllocationNoFill(cursor, align, offset);
Address end = start.plus(bytes);
VM.assertions._assert(end.LE(limit));
}
VM.memory.zero(cursor, limit.diff(cursor).toWord().toExtent());
if (VM.VERIFY_ASSERTIONS && Options.verbose.getValue() >= 9) {
Log.write("Z[");
Log.write(cursor);
Log.write("->");
Log.write(limit);
Log.writeln("]");
}
line = endLine;
if (VM.VERIFY_ASSERTIONS && copy) VM.assertions._assert(!Block.isDefragSource(cursor));
return true;
}
}
return false;
}
/**
* Copy <code>numbytes</code> from <code>src</code> to <code>dst</code>. Assumption either the
* ranges are non overlapping, or <code>src >= dst + BYTES_IN_ADDRESS</code>.
*
* @param dst The destination addr
* @param src The source addr
* @param numBytes The number of bytes to copy
*/
private static void internalAlignedWordCopy(Address dst, Address src, int numBytes) {
Address end = src.plus(numBytes);
while (src.LT(end)) {
dst.store(src.loadWord());
src = src.plus(BYTES_IN_ADDRESS);
dst = dst.plus(BYTES_IN_ADDRESS);
}
}
/**
* Copies a region of memory.
*
* @param dst Destination address
* @param src Source address
* @param cnt Number of bytes to copy
*/
public static void memcopy(Address dst, Address src, Extent cnt) {
Address srcEnd = src.plus(cnt);
Address dstEnd = dst.plus(cnt);
boolean overlap = !srcEnd.LE(dst) && !dstEnd.LE(src);
if (overlap) {
SysCall.sysCall.sysMemmove(dst, src, cnt);
} else {
SysCall.sysCall.sysCopy(dst, src, cnt);
}
}
@Inline
private static void copy8Bytes(Address dstPtr, Address srcPtr) {
if (BYTES_IN_COPY == 8) {
if (VM.BuildForIA32) {
dstPtr.store(srcPtr.loadLong());
} else {
dstPtr.store(srcPtr.loadDouble());
}
} else {
copy4Bytes(dstPtr, srcPtr);
copy4Bytes(dstPtr.plus(4), srcPtr.plus(4));
}
}
/**
* Low level copy of <code>copyBytes</code> bytes from <code>src[srcPos]</code> to <code>
* dst[dstPos]</code>.
*
* <p>Assumption <code>src != dst || (srcPos >= dstPos)</code> and element size is 8 bytes.
*
* @param dstPtr The destination start address
* @param srcPtr The source start address
* @param copyBytes The number of bytes to be copied
*/
public static void aligned64Copy(Address dstPtr, Address srcPtr, int copyBytes) {
if (USE_NATIVE && copyBytes > NATIVE_THRESHOLD) {
memcopy(dstPtr, srcPtr, copyBytes);
} else {
// The elements of long[] and double[] are always doubleword aligned
// therefore we can do 64 bit load/stores without worrying about alignment.
Address endPtr = srcPtr.plus(copyBytes);
while (srcPtr.LT(endPtr)) {
copy8Bytes(dstPtr, srcPtr);
srcPtr = srcPtr.plus(8);
dstPtr = dstPtr.plus(8);
}
}
}
/** Reference Arrays */
public static void referenceArray(Object object, TransitiveClosure trace) {
Address base = Magic.objectAsAddress(object);
int length = ObjectModel.getArrayLength(object);
for (int i = 0; i < length; i++) {
trace.processEdge(ObjectReference.fromObject(object), base.plus(i << LOG_BYTES_IN_ADDRESS));
}
}
/** All Scalars */
public static void scalar(Object object, TransitiveClosure trace) {
Address base = Magic.objectAsAddress(object);
int[] offsets = ObjectModel.getObjectType(object).asClass().getReferenceOffsets();
for (int i = 0; i < offsets.length; i++) {
trace.processEdge(ObjectReference.fromObject(object), base.plus(offsets[i]));
}
}
public static void dumpMemory(Address start, int beforeBytes, int afterBytes) {
beforeBytes = alignDown(beforeBytes, BYTES_IN_ADDRESS);
afterBytes = alignUp(afterBytes, BYTES_IN_ADDRESS);
VM.sysWrite("---- Dumping memory from ");
VM.sysWrite(start.minus(beforeBytes));
VM.sysWrite(" to ");
VM.sysWrite(start.plus(afterBytes));
VM.sysWrite(" ----\n");
for (int i = -beforeBytes; i < afterBytes; i += BYTES_IN_ADDRESS) {
VM.sysWrite(i, ": ");
VM.sysWrite(start.plus(i));
Word value = start.plus(i).loadWord();
VM.sysWriteln(" ", value);
}
}
@Inline
private boolean acquireRecyclableBlockAddressOrder() {
if (recyclableExhausted) {
if (VM.VERIFY_ASSERTIONS && Options.verbose.getValue() >= 9) {
Log.writeln("[no recyclable available]");
}
return false;
}
int markState = 0;
boolean usable = false;
while (!usable) {
Address next = recyclableBlock.plus(BYTES_IN_BLOCK);
if (recyclableBlock.isZero() || ImmixSpace.isRecycleAllocChunkAligned(next)) {
recyclableBlock = space.acquireReusableBlocks();
if (recyclableBlock.isZero()) {
recyclableExhausted = true;
if (VM.VERIFY_ASSERTIONS && Options.verbose.getValue() >= 9) {
Log.writeln("[recyclable exhausted]");
}
line = LINES_IN_BLOCK;
return false;
}
} else {
recyclableBlock = next;
}
markState = Block.getBlockMarkState(recyclableBlock);
usable = (markState > 0 && markState <= ImmixSpace.getReusuableMarkStateThreshold(copy));
if (copy && Block.isDefragSource(recyclableBlock)) usable = false;
}
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(!Block.isUnused(recyclableBlock));
Block.setBlockAsReused(recyclableBlock);
lineUseCount += (LINES_IN_BLOCK - markState);
return true; // found something good
}
@Inline
public static Address alignUp(Address address, int alignment) {
return address
.plus(alignment - 1)
.toWord()
.and(Word.fromIntSignExtend(~(alignment - 1)))
.toAddress();
}
/**
* Copy copyBytes from src to dst. Assumption: either the ranges are non overlapping, or {@code
* src >= dst + 4}. Also, src and dst are 4 byte aligned and numBytes is a multiple of 4.
*
* @param dst the destination addr
* @param src the source addr
* @param copyBytes the number of bytes top copy
*/
public static void aligned32Copy(Address dst, Address src, int copyBytes) {
if (VM.VerifyAssertions) {
VM._assert(copyBytes >= 0);
VM._assert((copyBytes & (BYTES_IN_INT - 1)) == 0);
VM._assert(src.toWord().and(Word.fromIntZeroExtend(BYTES_IN_INT - 1)).isZero());
VM._assert(dst.toWord().and(Word.fromIntZeroExtend(BYTES_IN_INT - 1)).isZero());
VM._assert(src.plus(copyBytes).LE(dst) || src.GE(dst.plus(BYTES_IN_INT)));
}
if (USE_NATIVE && copyBytes > NATIVE_THRESHOLD) {
memcopy(dst, src, copyBytes);
} else {
Offset numBytes = Offset.fromIntSignExtend(copyBytes);
if (BYTES_IN_COPY == 8 && copyBytes != 0) {
Word wordMask = Word.fromIntZeroExtend(BYTES_IN_COPY - 1);
Word srcAlignment = src.toWord().and(wordMask);
if (srcAlignment.EQ(dst.toWord().and(wordMask))) {
Offset i = Offset.zero();
if (srcAlignment.EQ(Word.fromIntZeroExtend(BYTES_IN_INT))) {
copy4Bytes(dst.plus(i), src.plus(i));
i = i.plus(BYTES_IN_INT);
}
Word endAlignment = srcAlignment.plus(numBytes).and(wordMask);
numBytes = numBytes.minus(endAlignment.toOffset());
for (; i.sLT(numBytes); i = i.plus(BYTES_IN_COPY)) {
copy8Bytes(dst.plus(i), src.plus(i));
}
if (!endAlignment.isZero()) {
copy4Bytes(dst.plus(i), src.plus(i));
}
return;
}
}
// normal case: 32 bit or (64 bit not aligned)
for (Offset i = Offset.zero(); i.sLT(numBytes); i = i.plus(BYTES_IN_INT)) {
copy4Bytes(dst.plus(i), src.plus(i));
}
}
}
/**
* Low level copy of <code>len</code> elements from <code>src[srcPos]</code> to <code>dst[dstPos]
* </code>.
*
* <p>Assumption: <code>src != dst || (srcPos >= dstPos)</code> and element size is 4 bytes.
*
* @param src the source array
* @param srcIdx index in the source array to begin copy
* @param dst the destination array
* @param dstIdx index in the destination array to being copy
* @param len number of array elements to copy
*/
@Inline
public static void arraycopy32Bit(Object src, int srcIdx, Object dst, int dstIdx, int len) {
Address srcPtr = VM_Magic.objectAsAddress(src).plus(srcIdx << LOG_BYTES_IN_INT);
Address dstPtr = VM_Magic.objectAsAddress(dst).plus(dstIdx << LOG_BYTES_IN_INT);
int copyBytes = len << LOG_BYTES_IN_INT;
if (USE_NATIVE && len > (NATIVE_THRESHOLD >> LOG_BYTES_IN_INT)) {
memcopy(dstPtr, srcPtr, copyBytes);
} else {
// The elements of int[] and float[] are always 32 bit aligned
// therefore we can do 32 bit load/stores without worrying about alignment.
// TODO: do measurements to determine if on PPC it is a good idea to check
// for compatible doubleword alignment and handle that case via the FPRs in 64 bit
// chunks.
// Unclear if this will be a big enough win to justify checking because for big copies
// we are going into memcopy anyways and that will be faster than anything we do here.
Address endPtr = srcPtr.plus(copyBytes);
while (srcPtr.LT(endPtr)) {
dstPtr.store(srcPtr.loadInt());
srcPtr = srcPtr.plus(4);
dstPtr = dstPtr.plus(4);
}
}
}
/**
* External allocation slow path (called by superclass when slow path is actually taken. This is
* necessary (rather than a direct call from the fast path) because of the possibility of a thread
* switch and corresponding re-association of bump pointers to kernel threads.
*
* @param bytes The number of bytes allocated
* @param align The requested alignment
* @param offset The offset from the alignment
* @return The address of the first byte of the allocated region or zero on failure
*/
protected final Address allocSlowOnce(int bytes, int align, int offset) {
Address ptr = space.getSpace(hot, copy, lineUseCount);
if (ptr.isZero()) {
lineUseCount = 0;
return ptr; // failed allocation --- we will need to GC
}
/* we have been given a clean block */
if (VM.VERIFY_ASSERTIONS) VM.assertions._assert(Block.isAligned(ptr));
lineUseCount = LINES_IN_BLOCK;
zeroBlock(ptr);
if (requestForLarge) {
largeCursor = ptr;
largeLimit = ptr.plus(BYTES_IN_BLOCK);
} else {
cursor = ptr;
limit = ptr.plus(BYTES_IN_BLOCK);
}
return alloc(bytes, align, offset);
}
/**
* Allocate space for a new object. This is frequently executed code and the coding is
* deliberaetly sensitive to the optimizing compiler. After changing this, always check the IR/MC
* that is generated.
*
* @param bytes The number of bytes allocated
* @param align The requested alignment
* @param offset The offset from the alignment
* @return The address of the first byte of the allocated region
*/
@Inline
public final Address alloc(int bytes, int align, int offset) {
/* establish how much we need */
Address start = alignAllocationNoFill(cursor, align, offset);
Address end = start.plus(bytes);
/* check whether we've exceeded the limit */
if (end.GT(limit)) {
if (bytes > BYTES_IN_LINE) return overflowAlloc(bytes, align, offset);
else return allocSlowHot(bytes, align, offset);
}
/* sufficient memory is available, so we can finish performing the allocation */
fillAlignmentGap(cursor, start);
cursor = end;
return start;
}
/**
* Allocate space for a new object. This is frequently executed code and the coding is
* deliberaetly sensitive to the optimizing compiler. After changing this, always check the IR/MC
* that is generated.
*
* @param bytes The number of bytes allocated
* @param align The requested alignment
* @param offset The offset from the alignment
* @return The address of the first byte of the allocated region
*/
public final Address overflowAlloc(int bytes, int align, int offset) {
/* establish how much we need */
Address start = alignAllocationNoFill(largeCursor, align, offset);
Address end = start.plus(bytes);
/* check whether we've exceeded the limit */
if (end.GT(largeLimit)) {
requestForLarge = true;
Address rtn = allocSlowInline(bytes, align, offset);
requestForLarge = false;
return rtn;
}
/* sufficient memory is available, so we can finish performing the allocation */
fillAlignmentGap(largeCursor, start);
largeCursor = end;
return start;
}
/** All patterns bottom out here */
@Inline
public static void pattern(int pattern, Object object, TransitiveClosure trace) {
Address base = Magic.objectAsAddress(object).plus(FIELD_ZERO_OFFSET);
if ((pattern & 1) != 0) {
trace.processEdge(ObjectReference.fromObject(object), base.plus(0));
}
if ((pattern & 2) != 0) {
trace.processEdge(ObjectReference.fromObject(object), base.plus(1 << LOG_BYTES_IN_ADDRESS));
}
if ((pattern & 4) != 0) {
trace.processEdge(ObjectReference.fromObject(object), base.plus(2 << LOG_BYTES_IN_ADDRESS));
}
if ((pattern & 8) != 0) {
trace.processEdge(ObjectReference.fromObject(object), base.plus(3 << LOG_BYTES_IN_ADDRESS));
}
if ((pattern & 16) != 0) {
trace.processEdge(ObjectReference.fromObject(object), base.plus(4 << LOG_BYTES_IN_ADDRESS));
}
if ((pattern & 32) != 0) {
trace.processEdge(ObjectReference.fromObject(object), base.plus(5 << LOG_BYTES_IN_ADDRESS));
}
}
/**
* Low level copy of len elements from src[srcPos] to dst[dstPos].
*
* <p>Assumptions: <code> src != dst || (scrPos >= dstPos + 4) </code> and src and dst are 8Bit
* arrays.
*
* @param src the source array
* @param srcPos index in the source array to begin copy
* @param dst the destination array
* @param dstPos index in the destination array to being copy
* @param len number of array elements to copy
*/
@Inline
public static void arraycopy8Bit(Object src, int srcPos, Object dst, int dstPos, int len) {
if (USE_NATIVE && len > NATIVE_THRESHOLD) {
memcopy(
VM_Magic.objectAsAddress(dst).plus(dstPos),
VM_Magic.objectAsAddress(src).plus(srcPos),
len);
} else {
if (len >= BYTES_IN_ADDRESS
&& (srcPos & (BYTES_IN_ADDRESS - 1)) == (dstPos & (BYTES_IN_ADDRESS - 1))) {
// relative alignment is the same
int byteStart = srcPos;
int wordStart = alignUp(srcPos, BYTES_IN_ADDRESS);
int wordEnd = alignDown(srcPos + len, BYTES_IN_ADDRESS);
int byteEnd = srcPos + len;
int startDiff = wordStart - byteStart;
int endDiff = byteEnd - wordEnd;
int wordLen = wordEnd - wordStart;
Address srcPtr = VM_Magic.objectAsAddress(src).plus(srcPos + startDiff);
Address dstPtr = VM_Magic.objectAsAddress(dst).plus(dstPos + startDiff);
if (VM.BuildFor64Addr) {
switch (startDiff) {
case 7:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(-7)), Offset.fromIntSignExtend(-7));
case 6:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(-6)), Offset.fromIntSignExtend(-6));
case 5:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(-5)), Offset.fromIntSignExtend(-5));
case 4:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(-4)), Offset.fromIntSignExtend(-4));
case 3:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(-3)), Offset.fromIntSignExtend(-3));
case 2:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(-2)), Offset.fromIntSignExtend(-2));
case 1:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(-1)), Offset.fromIntSignExtend(-1));
}
} else {
switch (startDiff) {
case 3:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(-3)), Offset.fromIntSignExtend(-3));
case 2:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(-2)), Offset.fromIntSignExtend(-2));
case 1:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(-1)), Offset.fromIntSignExtend(-1));
}
}
Address endPtr = srcPtr.plus(wordLen);
while (srcPtr.LT(endPtr)) {
dstPtr.store(srcPtr.loadWord());
srcPtr = srcPtr.plus(BYTES_IN_ADDRESS);
dstPtr = dstPtr.plus(BYTES_IN_ADDRESS);
}
if (VM.BuildFor64Addr) {
switch (endDiff) {
case 7:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(6)), Offset.fromIntSignExtend(6));
case 6:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(5)), Offset.fromIntSignExtend(5));
case 5:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(4)), Offset.fromIntSignExtend(4));
case 4:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(3)), Offset.fromIntSignExtend(3));
case 3:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(2)), Offset.fromIntSignExtend(2));
case 2:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(1)), Offset.fromIntSignExtend(1));
case 1:
dstPtr.store(srcPtr.loadByte());
}
} else {
switch (endDiff) {
case 3:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(2)), Offset.fromIntSignExtend(2));
case 2:
dstPtr.store(
srcPtr.loadByte(Offset.fromIntSignExtend(1)), Offset.fromIntSignExtend(1));
case 1:
dstPtr.store(srcPtr.loadByte());
}
}
} else {
Address srcPtr = VM_Magic.objectAsAddress(src).plus(srcPos);
Address dstPtr = VM_Magic.objectAsAddress(dst).plus(dstPos);
Address endPtr = srcPtr.plus(len);
while (srcPtr.LT(endPtr)) {
dstPtr.store(srcPtr.loadByte());
srcPtr = srcPtr.plus(1);
dstPtr = dstPtr.plus(1);
}
}
}
}
/**
* Low level copy of len elements from src[srcPos] to dst[dstPos].
*
* <p>Assumption src != dst || (srcPos >= dstPos + 2).
*
* @param src the source array
* @param srcPos index in the source array to begin copy
* @param dst the destination array
* @param dstPos index in the destination array to being copy
* @param len number of array elements to copy
*/
@Inline
public static void arraycopy16Bit(Object src, int srcPos, Object dst, int dstPos, int len) {
if (USE_NATIVE && len > (NATIVE_THRESHOLD >> LOG_BYTES_IN_SHORT)) {
memcopy(
VM_Magic.objectAsAddress(dst).plus(dstPos << LOG_BYTES_IN_SHORT),
VM_Magic.objectAsAddress(src).plus(srcPos << LOG_BYTES_IN_SHORT),
len << LOG_BYTES_IN_SHORT);
} else {
if (len >= (BYTES_IN_ADDRESS >>> LOG_BYTES_IN_SHORT)
&& (srcPos & ((BYTES_IN_ADDRESS - 1) >>> LOG_BYTES_IN_SHORT))
== (dstPos & ((BYTES_IN_ADDRESS - 1) >>> LOG_BYTES_IN_SHORT))) {
// relative alignment is the same
int byteStart = srcPos << LOG_BYTES_IN_SHORT;
int wordStart = alignUp(byteStart, BYTES_IN_ADDRESS);
int wordEnd = alignDown(byteStart + (len << LOG_BYTES_IN_SHORT), BYTES_IN_ADDRESS);
int byteEnd = byteStart + (len << LOG_BYTES_IN_SHORT);
int startDiff = wordStart - byteStart;
int endDiff = byteEnd - wordEnd;
int wordLen = wordEnd - wordStart;
Address srcPtr =
VM_Magic.objectAsAddress(src).plus((srcPos << LOG_BYTES_IN_SHORT) + startDiff);
Address dstPtr =
VM_Magic.objectAsAddress(dst).plus((dstPos << LOG_BYTES_IN_SHORT) + startDiff);
if (VM.BuildFor64Addr) {
switch (startDiff) {
case 6:
dstPtr.store(
srcPtr.loadChar(Offset.fromIntSignExtend(-6)), Offset.fromIntSignExtend(-6));
case 4:
dstPtr.store(
srcPtr.loadChar(Offset.fromIntSignExtend(-4)), Offset.fromIntSignExtend(-4));
case 2:
dstPtr.store(
srcPtr.loadChar(Offset.fromIntSignExtend(-2)), Offset.fromIntSignExtend(-2));
}
} else {
if (startDiff == 2) {
dstPtr.store(
srcPtr.loadChar(Offset.fromIntSignExtend(-2)), Offset.fromIntSignExtend(-2));
}
}
Address endPtr = srcPtr.plus(wordLen);
while (srcPtr.LT(endPtr)) {
dstPtr.store(srcPtr.loadWord());
srcPtr = srcPtr.plus(BYTES_IN_ADDRESS);
dstPtr = dstPtr.plus(BYTES_IN_ADDRESS);
}
if (VM.BuildFor64Addr) {
switch (endDiff) {
case 6:
dstPtr.store(
srcPtr.loadChar(Offset.fromIntSignExtend(4)), Offset.fromIntSignExtend(4));
case 4:
dstPtr.store(
srcPtr.loadChar(Offset.fromIntSignExtend(2)), Offset.fromIntSignExtend(2));
case 2:
dstPtr.store(srcPtr.loadChar());
}
} else {
if (endDiff == 2) {
dstPtr.store(srcPtr.loadChar());
}
}
} else {
Address srcPtr = VM_Magic.objectAsAddress(src).plus(srcPos << LOG_BYTES_IN_CHAR);
Address dstPtr = VM_Magic.objectAsAddress(dst).plus(dstPos << LOG_BYTES_IN_CHAR);
Address endPtr = srcPtr.plus(len << LOG_BYTES_IN_CHAR);
while (srcPtr.LT(endPtr)) {
dstPtr.store(srcPtr.loadChar());
srcPtr = srcPtr.plus(2);
dstPtr = dstPtr.plus(2);
}
}
}
}
/**
* Low level copy of <code>copyBytes</code> bytes from <code>src[srcPos]</code> to <code>
* dst[dstPos]</code>.
*
* <p>Assumption: <code>src != dst || (srcPos >= dstPos)</code> and element size is 2 bytes.
*
* @param dstPtr The destination start address
* @param srcPtr The source start address
* @param copyBytes The number of bytes to be copied
*/
public static void aligned16Copy(Address dstPtr, Address srcPtr, int copyBytes) {
if (USE_NATIVE && copyBytes > NATIVE_THRESHOLD) {
memcopy(dstPtr, srcPtr, copyBytes);
} else {
if (copyBytes >= BYTES_IN_COPY
&& (srcPtr.toWord().and(Word.fromIntZeroExtend(BYTES_IN_COPY - 1))
== (dstPtr.toWord().and(Word.fromIntZeroExtend(BYTES_IN_COPY - 1))))) {
// relative alignment is the same
Address endPtr = srcPtr.plus(copyBytes);
Address wordEndPtr =
endPtr.toWord().and(Word.fromIntZeroExtend(BYTES_IN_COPY - 1).not()).toAddress();
if (BYTES_IN_COPY == 8) {
if (srcPtr.toWord().and(Word.fromIntZeroExtend(2)).NE(Word.zero())) {
copy2Bytes(dstPtr, srcPtr);
srcPtr = srcPtr.plus(2);
dstPtr = dstPtr.plus(2);
}
if (srcPtr.toWord().and(Word.fromIntZeroExtend(4)).NE(Word.zero())) {
copy4Bytes(dstPtr, srcPtr);
srcPtr = srcPtr.plus(4);
dstPtr = dstPtr.plus(4);
}
} else {
if (srcPtr.toWord().and(Word.fromIntZeroExtend(2)).NE(Word.zero())) {
copy2Bytes(dstPtr, srcPtr);
srcPtr = srcPtr.plus(2);
dstPtr = dstPtr.plus(2);
}
}
while (srcPtr.LT(wordEndPtr)) {
if (BYTES_IN_COPY == 8) {
copy8Bytes(dstPtr, srcPtr);
} else {
copy4Bytes(dstPtr, srcPtr);
}
srcPtr = srcPtr.plus(BYTES_IN_COPY);
dstPtr = dstPtr.plus(BYTES_IN_COPY);
}
// if(VM.VerifyAssertions) VM._assert(wordEndPtr.EQ(srcPtr));
if (BYTES_IN_COPY == 8) {
if (endPtr.toWord().and(Word.fromIntZeroExtend(4)).NE(Word.zero())) {
copy4Bytes(dstPtr, srcPtr);
srcPtr = srcPtr.plus(4);
dstPtr = dstPtr.plus(4);
}
if (endPtr.toWord().and(Word.fromIntZeroExtend(2)).NE(Word.zero())) {
copy2Bytes(dstPtr, srcPtr);
}
} else {
if (endPtr.toWord().and(Word.fromIntZeroExtend(2)).NE(Word.zero())) {
copy2Bytes(dstPtr, srcPtr);
}
}
} else {
Address endPtr = srcPtr.plus(copyBytes);
while (srcPtr.LT(endPtr)) {
copy2Bytes(dstPtr, srcPtr);
srcPtr = srcPtr.plus(2);
dstPtr = dstPtr.plus(2);
}
}
}
}