/**
* Provides fine-tuned implementation for IDIV/IREM operations on IA32-compatible platforms,
* in replacement of common arithmetic helper (see arith_rt.h).
*/
bool CodeGen::gen_a_platf(JavaByteCodes op, jtype jt)
{
if (jt != i32) return false;
if (op != OPCODE_IDIV && op != OPCODE_IREM) {
return false;
}
//
// The method is supposed to be platform-depended, and may not have
// Encoder support - leaving as-is, without implementing general
// support in Encoder
//
vpark(eax.reg());
vpark(edx.reg());
rlock(eax);
rlock(edx);
Val& v1 = vstack(1, vis_imm(1));
Val& v2 = vstack(0, true);
alu(alu_cmp, v2.as_opnd(), Opnd(-1));
unsigned br_normal = br(ne, 0, 0);
alu(alu_cmp, v1.as_opnd(), Opnd(INT_MIN));
unsigned br_exit = NOTHING;
if (op == OPCODE_IREM) {
do_mov(edx, Opnd(0)); // prepare exit value for the corner case
br_exit = br(eq, 0, 0);
}
else {
do_mov(eax, v1);
br_exit = br(eq, 0, 0);
}
patch(br_normal, ip());
do_mov(eax, v1);
//
// The method is supposed to be platform-depended, and may not have
// Encoder support - leaving as-is, without implementing general
// support in Encoder
//
//CDQ
EncoderBase::Operands args0(RegName_EDX, RegName_EAX);
ip(EncoderBase::encode(ip(), Mnemonic_CDQ, args0));
//IDIV
EncoderBase::Operands args(RegName_EDX, RegName_EAX,
devirt(v2.reg(), i32));
ip(EncoderBase::encode(ip(), Mnemonic_IDIV, args));
patch(br_exit, ip());
vpop();
vpop();
vpush(op == OPCODE_IREM ? edx : eax);
runlock(eax);
runlock(edx);
return true;
}
void Compiler::handle_inst(void)
{
// is it last instruction in basic block ?
//const bool last = m_bbinfo->last_pc == jinst.pc;
const JInst& jinst = m_insts[m_pc];
unsigned bc_size = m_infoBlock.get_bc_size();
bool lastInBB = jinst.next>=bc_size || (m_insts[jinst.next].flags & OPF_STARTS_BB);
if (is_set(DBG_CHECK_STACK)) {
gen_dbg_check_stack(true);
}
// First test if this is a magic. If not, then proceed with regular
// code gen.
if (!gen_magic()) {
const InstrDesc& idesc = instrs[jinst.opcode];
switch (idesc.ik) {
case ik_a:
handle_ik_a(jinst);
break;
case ik_cf:
handle_ik_cf(jinst);
break;
case ik_cnv:
handle_ik_cnv(jinst);
break;
case ik_ls:
handle_ik_ls(jinst);
break;
case ik_meth:
handle_ik_meth(jinst);
break;
case ik_obj:
handle_ik_obj(jinst);
break;
case ik_stack:
handle_ik_stack(jinst);
break;
case ik_throw:
gen_athrow();
break;
default:
assert(jinst.opcode == OPCODE_NOP);
break;
} // ~switch(opcodegroup)
} else { // if (!gen_magic()) {
// no op. Just check stack (if applicable) and do mem manipulations
}
if (is_set(DBG_CHECK_STACK)) {
gen_dbg_check_stack(false);
}
if (g_jvmtiMode) {
// Do not allow values to cross instruction boundaries
// on a temporary registers
vpark();
// We must have GC info at every bytecode instruction
// to support possible enumeration at a breakpoint
gen_gc_stack(-1, false);
}
const bool has_fall_through = !jinst.is_set(OPF_DEAD_END);
if (lastInBB && has_fall_through && jinst.get_num_targets() == 0) {
gen_bb_leave(jinst.next);
}
}