void main(void)
{
unsigned long int i, result;
clock_t start_time, stop_time;
printf("Processing...\n");
start_time = clock();
for (i = 0; i < 2000000L; i++)
result = add_fast(i, -i);
stop_time = clock();
printf("Processing time for fast call %d ticks\n",
stop_time - start_time);
start_time = clock();
for (i = 0; i < 2000000L; i++)
result = add_slow(i, -i);
stop_time = clock();
printf("Processing time for normal call %d ticks\n",
stop_time - start_time);
}
VtableStub* VtableStubs::create_itable_stub(int itable_index) {
const int code_length = VtableStub::pd_code_size_limit(false);
VtableStub* s = new(code_length) VtableStub(false, itable_index);
// Can be NULL if there is no free space in the code cache.
if (s == NULL) {
return NULL;
}
ResourceMark rm;
CodeBuffer cb(s->entry_point(), code_length);
MacroAssembler* masm = new MacroAssembler(&cb);
assert(VtableStub::receiver_location() == R0->as_VMReg(), "receiver expected in R0");
// R0-R3 / R0-R7 registers hold the arguments and cannot be spoiled
const Register Rclass = AARCH64_ONLY(R9) NOT_AARCH64(R4);
const Register Rlength = AARCH64_ONLY(R10) NOT_AARCH64(R5);
const Register Rscan = AARCH64_ONLY(R11) NOT_AARCH64(R6);
const Register tmp = Rtemp;
assert_different_registers(Ricklass, Rclass, Rlength, Rscan, tmp);
// Calculate the start of itable (itable goes after vtable)
const int scale = exact_log2(vtableEntry::size_in_bytes());
address npe_addr = __ pc();
__ load_klass(Rclass, R0);
__ ldr_s32(Rlength, Address(Rclass, Klass::vtable_length_offset()));
__ add(Rscan, Rclass, in_bytes(Klass::vtable_start_offset()));
__ add(Rscan, Rscan, AsmOperand(Rlength, lsl, scale));
// Search through the itable for an interface equal to incoming Ricklass
// itable looks like [intface][offset][intface][offset][intface][offset]
const int entry_size = itableOffsetEntry::size() * HeapWordSize;
assert(itableOffsetEntry::interface_offset_in_bytes() == 0, "not added for convenience");
Label loop;
__ bind(loop);
__ ldr(tmp, Address(Rscan, entry_size, post_indexed));
#ifdef AARCH64
Label found;
__ cmp(tmp, Ricklass);
__ b(found, eq);
__ cbnz(tmp, loop);
#else
__ cmp(tmp, Ricklass); // set ZF and CF if interface is found
__ cmn(tmp, 0, ne); // check if tmp == 0 and clear CF if it is
__ b(loop, ne);
#endif // AARCH64
assert(StubRoutines::throw_IncompatibleClassChangeError_entry() != NULL, "Check initialization order");
#ifdef AARCH64
__ jump(StubRoutines::throw_IncompatibleClassChangeError_entry(), relocInfo::runtime_call_type, tmp);
__ bind(found);
#else
// CF == 0 means we reached the end of itable without finding icklass
__ jump(StubRoutines::throw_IncompatibleClassChangeError_entry(), relocInfo::runtime_call_type, noreg, cc);
#endif // !AARCH64
// Interface found at previous position of Rscan, now load the method oop
__ ldr_s32(tmp, Address(Rscan, itableOffsetEntry::offset_offset_in_bytes() - entry_size));
{
const int method_offset = itableMethodEntry::size() * HeapWordSize * itable_index +
itableMethodEntry::method_offset_in_bytes();
__ add_slow(Rmethod, Rclass, method_offset);
}
__ ldr(Rmethod, Address(Rmethod, tmp));
address ame_addr = __ pc();
#ifdef AARCH64
__ ldr(tmp, Address(Rmethod, Method::from_compiled_offset()));
__ br(tmp);
#else
__ ldr(PC, Address(Rmethod, Method::from_compiled_offset()));
#endif // AARCH64
masm->flush();
if (PrintMiscellaneous && (WizardMode || Verbose)) {
tty->print_cr("itable #%d at " PTR_FORMAT "[%d] left over: %d",
itable_index, p2i(s->entry_point()),
(int)(s->code_end() - s->entry_point()),
(int)(s->code_end() - __ pc()));
}
guarantee(__ pc() <= s->code_end(), "overflowed buffer");
// FIXME ARM: need correct 'slop' - below is x86 code
// shut the door on sizing bugs
//int slop = 8; // 32-bit offset is this much larger than a 13-bit one
//assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for 32-bit offset");
s->set_exception_points(npe_addr, ame_addr);
return s;
}
