private static void shiftIndex0(
CodeIterator ci, int index, int opcode, int lessThan, int delta, int opcode_i_0, int opcode_i)
throws BadBytecode {
int var = (opcode - opcode_i_0) % 4;
if (var < lessThan) return;
var += delta;
if (var < 4) ci.writeByte(opcode + delta, index);
else {
opcode = (opcode - opcode_i_0) / 4 + opcode_i;
if (var < 0x100) {
int pos = ci.insertExGap(1);
ci.writeByte(opcode, pos - 1);
ci.writeByte(var, pos);
} else {
int pos = ci.insertExGap(3);
ci.writeByte(WIDE, pos - 1);
ci.writeByte(opcode, pos);
ci.write16bit(var, pos + 1);
}
}
}
private static void shiftIndex8(CodeIterator ci, int index, int opcode, int lessThan, int delta)
throws BadBytecode {
int var = ci.byteAt(index + 1);
if (var < lessThan) return;
var += delta;
if (var < 0x100) ci.writeByte(var, index + 1);
else {
int pos = ci.insertExGap(2);
ci.writeByte(WIDE, pos - 2);
ci.writeByte(opcode, pos - 1);
ci.write16bit(var, pos);
}
}
/**
* @param lessThan If the index of the local variable is less than this value, it does not change.
* Otherwise, the index is increased.
* @param delta the indexes of the local variables are increased by this value.
*/
private static void shiftIndex(CodeIterator ci, int lessThan, int delta) throws BadBytecode {
int index = ci.next();
int opcode = ci.byteAt(index);
if (opcode < ILOAD) return;
else if (opcode < IASTORE) {
if (opcode < ILOAD_0) {
// iload, lload, fload, dload, aload
shiftIndex8(ci, index, opcode, lessThan, delta);
} else if (opcode < IALOAD) {
// iload_0, ..., aload_3
shiftIndex0(ci, index, opcode, lessThan, delta, ILOAD_0, ILOAD);
} else if (opcode < ISTORE) return;
else if (opcode < ISTORE_0) {
// istore, lstore, ...
shiftIndex8(ci, index, opcode, lessThan, delta);
} else {
// istore_0, ..., astore_3
shiftIndex0(ci, index, opcode, lessThan, delta, ISTORE_0, ISTORE);
}
} else if (opcode == IINC) {
int var = ci.byteAt(index + 1);
if (var < lessThan) return;
var += delta;
if (var < 0x100) ci.writeByte(var, index + 1);
else {
int plus = (byte) ci.byteAt(index + 2);
int pos = ci.insertExGap(3);
ci.writeByte(WIDE, pos - 3);
ci.writeByte(IINC, pos - 2);
ci.write16bit(var, pos - 1);
ci.write16bit(plus, pos + 1);
}
} else if (opcode == RET) shiftIndex8(ci, index, opcode, lessThan, delta);
else if (opcode == WIDE) {
int var = ci.u16bitAt(index + 2);
if (var < lessThan) return;
var += delta;
ci.write16bit(var, index + 2);
}
}
