// for: _iadd, _imul, _isub, _idiv, _irem
void LIRGenerator::do_ArithmeticOp_Int(ArithmeticOp* x) {
bool is_div_rem = x->op() == Bytecodes::_idiv || x->op() == Bytecodes::_irem;
LIRItem left(x->x(), this);
LIRItem right(x->y(), this);
// missing test if instr is commutative and if we should swap
right.load_nonconstant();
assert(right.is_constant() || right.is_register(), "wrong state of right");
left.load_item();
rlock_result(x);
if (is_div_rem) {
CodeEmitInfo* info = state_for(x);
LIR_Opr tmp = FrameMap::G1_opr;
if (x->op() == Bytecodes::_irem) {
__ irem(left.result(), right.result(), x->operand(), tmp, info);
} else if (x->op() == Bytecodes::_idiv) {
__ idiv(left.result(), right.result(), x->operand(), tmp, info);
}
} else {
arithmetic_op_int(x->op(), x->operand(), left.result(), right.result(), FrameMap::G1_opr);
}
}
// for: _iadd, _imul, _isub, _idiv, _irem
void LIRGenerator::do_ArithmeticOp_Int(ArithmeticOp* x) {
if (x->op() == Bytecodes::_idiv || x->op() == Bytecodes::_irem) {
// The requirements for division and modulo
// input : rax,: dividend min_int
// reg: divisor (may not be rax,/rdx) -1
//
// output: rax,: quotient (= rax, idiv reg) min_int
// rdx: remainder (= rax, irem reg) 0
// rax, and rdx will be destroyed
// Note: does this invalidate the spec ???
LIRItem right(x->y(), this);
LIRItem left(x->x() , this); // visit left second, so that the is_register test is valid
// call state_for before load_item_force because state_for may
// force the evaluation of other instructions that are needed for
// correct debug info. Otherwise the live range of the fix
// register might be too long.
CodeEmitInfo* info = state_for(x);
left.load_item_force(divInOpr());
right.load_item();
LIR_Opr result = rlock_result(x);
LIR_Opr result_reg;
if (x->op() == Bytecodes::_idiv) {
result_reg = divOutOpr();
} else {
result_reg = remOutOpr();
}
if (!ImplicitDiv0Checks) {
__ cmp(lir_cond_equal, right.result(), LIR_OprFact::intConst(0));
__ branch(lir_cond_equal, T_INT, new DivByZeroStub(info));
}
LIR_Opr tmp = FrameMap::rdx_opr; // idiv and irem use rdx in their implementation
if (x->op() == Bytecodes::_irem) {
__ irem(left.result(), right.result(), result_reg, tmp, info);
} else if (x->op() == Bytecodes::_idiv) {
__ idiv(left.result(), right.result(), result_reg, tmp, info);
} else {
ShouldNotReachHere();
}
__ move(result_reg, result);
} else {
// missing test if instr is commutative and if we should swap
LIRItem left(x->x(), this);
LIRItem right(x->y(), this);
LIRItem* left_arg = &left;
LIRItem* right_arg = &right;
if (x->is_commutative() && left.is_stack() && right.is_register()) {
// swap them if left is real stack (or cached) and right is real register(not cached)
left_arg = &right;
right_arg = &left;
}
left_arg->load_item();
// do not need to load right, as we can handle stack and constants
if (x->op() == Bytecodes::_imul ) {
// check if we can use shift instead
bool use_constant = false;
bool use_tmp = false;
if (right_arg->is_constant()) {
int iconst = right_arg->get_jint_constant();
if (iconst > 0) {
if (is_power_of_2(iconst)) {
use_constant = true;
} else if (is_power_of_2(iconst - 1) || is_power_of_2(iconst + 1)) {
use_constant = true;
use_tmp = true;
}
}
}
if (use_constant) {
right_arg->dont_load_item();
} else {
right_arg->load_item();
}
LIR_Opr tmp = LIR_OprFact::illegalOpr;
if (use_tmp) {
tmp = new_register(T_INT);
}
rlock_result(x);
arithmetic_op_int(x->op(), x->operand(), left_arg->result(), right_arg->result(), tmp);
} else {
right_arg->dont_load_item();
rlock_result(x);
LIR_Opr tmp = LIR_OprFact::illegalOpr;
arithmetic_op_int(x->op(), x->operand(), left_arg->result(), right_arg->result(), tmp);
}
}
}
