/**
* evaluates an instruction and determines if it will result in true or false on TOS.
*
* @param i is an instruction to analyze
* @return whether TOS is true, false, or not known
*/
private static ConstantBoolean isTrueInstructionInfo(InstructionInfo i) {
ConstantBoolean ret = ConstantBoolean.DONT_KNOW;
switch (i.getOpcode()) {
case OP_pushtrue:
ret = ConstantBoolean.TRUE;
break;
case OP_pushfalse:
ret = ConstantBoolean.FALSE;
break;
case OP_pushbyte:
{
int value = i.getImmediate();
assert value >= 0;
ret = ECMASupport.toBoolean(value) ? ConstantBoolean.TRUE : ConstantBoolean.FALSE;
break;
}
case OP_pushint:
{
int value = (Integer) i.getOperand(0);
ret = ECMASupport.toBoolean(value) ? ConstantBoolean.TRUE : ConstantBoolean.FALSE;
break;
}
case OP_pushuint:
{
long value = (Long) i.getOperand(0);
ret = ECMASupport.toBoolean(value) ? ConstantBoolean.TRUE : ConstantBoolean.FALSE;
break;
}
case OP_pushstring:
{
String value = i.getOperand(0).toString();
ret = ECMASupport.toBoolean(value) ? ConstantBoolean.TRUE : ConstantBoolean.FALSE;
break;
}
case OP_pushnull:
ret = ConstantBoolean.FALSE;
break;
}
return ret;
}
/**
* Optimizations for OP_convert_d: convert_d, convert_d -> convert_d pushbyte n, convert_d ->
* pushdouble n pushint n, convert_d -> pushdouble n pushuint n, convert_d -> pushdouble n
* pushdouble n, convert_d -> pushdouble n pushnan, convert_d -> pushnan lf32, convert_d -> lf32
* lf64, convert_d -> lf64
*
* @param i The convert_d instruction
*/
private void op_convert_d(InstructionInfo i) {
InstructionInfo prev = previous(1);
switch (prev.getOpcode()) {
case OP_pushbyte:
{
// replace pushbyte, convert d with pushdouble - should be faster
replace(
1,
InstructionFactory.getInstruction(
OP_pushdouble, new Double(convertByteImmediateToDouble(prev.getImmediate()))));
break;
}
case OP_pushint:
case OP_pushuint:
{
// replace pushint , convert d with pushdouble - should be faster
replace(
1,
InstructionFactory.getInstruction(
OP_pushdouble, new Double(((Number) prev.getOperand(0)).doubleValue())));
break;
}
case OP_pushdouble:
case OP_pushnan:
case OP_lf32:
case OP_lf64:
case OP_convert_d:
{
// result is already a double, just erase the op_convert_d
delete(0);
break;
}
default:
{
// nothing to do - instruction has already been added
}
}
}
