view src/cpu/x86/vm/c1_CodeStubs_x86.cpp @ 453:c96030fff130

6684579: SoftReference processing can be made more efficient Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not. Reviewed-by: jmasa
author ysr
date Thu, 20 Nov 2008 16:56:09 -0800
parents eb28cf662f56
children 3cf667df43ef
line wrap: on
line source

/*
 * Copyright 1999-2008 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

#include "incls/_precompiled.incl"
#include "incls/_c1_CodeStubs_x86.cpp.incl"


#define __ ce->masm()->

float ConversionStub::float_zero = 0.0;
double ConversionStub::double_zero = 0.0;

void ConversionStub::emit_code(LIR_Assembler* ce) {
  __ bind(_entry);
  assert(bytecode() == Bytecodes::_f2i || bytecode() == Bytecodes::_d2i, "other conversions do not require stub");


  if (input()->is_single_xmm()) {
    __ comiss(input()->as_xmm_float_reg(),
              ExternalAddress((address)&float_zero));
  } else if (input()->is_double_xmm()) {
    __ comisd(input()->as_xmm_double_reg(),
              ExternalAddress((address)&double_zero));
  } else {
    LP64_ONLY(ShouldNotReachHere());
    __ push(rax);
    __ ftst();
    __ fnstsw_ax();
    __ sahf();
    __ pop(rax);
  }

  Label NaN, do_return;
  __ jccb(Assembler::parity, NaN);
  __ jccb(Assembler::below, do_return);

  // input is > 0 -> return maxInt
  // result register already contains 0x80000000, so subtracting 1 gives 0x7fffffff
  __ decrement(result()->as_register());
  __ jmpb(do_return);

  // input is NaN -> return 0
  __ bind(NaN);
  __ xorptr(result()->as_register(), result()->as_register());

  __ bind(do_return);
  __ jmp(_continuation);
}

#ifdef TIERED
void CounterOverflowStub::emit_code(LIR_Assembler* ce) {
  __ bind(_entry);
  ce->store_parameter(_bci, 0);
  __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::counter_overflow_id)));
  ce->add_call_info_here(_info);
  ce->verify_oop_map(_info);

  __ jmp(_continuation);
}
#endif // TIERED



RangeCheckStub::RangeCheckStub(CodeEmitInfo* info, LIR_Opr index,
                               bool throw_index_out_of_bounds_exception)
  : _throw_index_out_of_bounds_exception(throw_index_out_of_bounds_exception)
  , _index(index)
{
  _info = info == NULL ? NULL : new CodeEmitInfo(info);
}


void RangeCheckStub::emit_code(LIR_Assembler* ce) {
  __ bind(_entry);
  // pass the array index on stack because all registers must be preserved
  if (_index->is_cpu_register()) {
    ce->store_parameter(_index->as_register(), 0);
  } else {
    ce->store_parameter(_index->as_jint(), 0);
  }
  Runtime1::StubID stub_id;
  if (_throw_index_out_of_bounds_exception) {
    stub_id = Runtime1::throw_index_exception_id;
  } else {
    stub_id = Runtime1::throw_range_check_failed_id;
  }
  __ call(RuntimeAddress(Runtime1::entry_for(stub_id)));
  ce->add_call_info_here(_info);
  debug_only(__ should_not_reach_here());
}


void DivByZeroStub::emit_code(LIR_Assembler* ce) {
  if (_offset != -1) {
    ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
  }
  __ bind(_entry);
  __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::throw_div0_exception_id)));
  ce->add_call_info_here(_info);
  debug_only(__ should_not_reach_here());
}


// Implementation of NewInstanceStub

NewInstanceStub::NewInstanceStub(LIR_Opr klass_reg, LIR_Opr result, ciInstanceKlass* klass, CodeEmitInfo* info, Runtime1::StubID stub_id) {
  _result = result;
  _klass = klass;
  _klass_reg = klass_reg;
  _info = new CodeEmitInfo(info);
  assert(stub_id == Runtime1::new_instance_id                 ||
         stub_id == Runtime1::fast_new_instance_id            ||
         stub_id == Runtime1::fast_new_instance_init_check_id,
         "need new_instance id");
  _stub_id   = stub_id;
}


void NewInstanceStub::emit_code(LIR_Assembler* ce) {
  assert(__ rsp_offset() == 0, "frame size should be fixed");
  __ bind(_entry);
  __ movptr(rdx, _klass_reg->as_register());
  __ call(RuntimeAddress(Runtime1::entry_for(_stub_id)));
  ce->add_call_info_here(_info);
  ce->verify_oop_map(_info);
  assert(_result->as_register() == rax, "result must in rax,");
  __ jmp(_continuation);
}


// Implementation of NewTypeArrayStub

NewTypeArrayStub::NewTypeArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
  _klass_reg = klass_reg;
  _length = length;
  _result = result;
  _info = new CodeEmitInfo(info);
}


void NewTypeArrayStub::emit_code(LIR_Assembler* ce) {
  assert(__ rsp_offset() == 0, "frame size should be fixed");
  __ bind(_entry);
  assert(_length->as_register() == rbx, "length must in rbx,");
  assert(_klass_reg->as_register() == rdx, "klass_reg must in rdx");
  __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::new_type_array_id)));
  ce->add_call_info_here(_info);
  ce->verify_oop_map(_info);
  assert(_result->as_register() == rax, "result must in rax,");
  __ jmp(_continuation);
}


// Implementation of NewObjectArrayStub

NewObjectArrayStub::NewObjectArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
  _klass_reg = klass_reg;
  _result = result;
  _length = length;
  _info = new CodeEmitInfo(info);
}


void NewObjectArrayStub::emit_code(LIR_Assembler* ce) {
  assert(__ rsp_offset() == 0, "frame size should be fixed");
  __ bind(_entry);
  assert(_length->as_register() == rbx, "length must in rbx,");
  assert(_klass_reg->as_register() == rdx, "klass_reg must in rdx");
  __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::new_object_array_id)));
  ce->add_call_info_here(_info);
  ce->verify_oop_map(_info);
  assert(_result->as_register() == rax, "result must in rax,");
  __ jmp(_continuation);
}


// Implementation of MonitorAccessStubs

MonitorEnterStub::MonitorEnterStub(LIR_Opr obj_reg, LIR_Opr lock_reg, CodeEmitInfo* info)
: MonitorAccessStub(obj_reg, lock_reg)
{
  _info = new CodeEmitInfo(info);
}


void MonitorEnterStub::emit_code(LIR_Assembler* ce) {
  assert(__ rsp_offset() == 0, "frame size should be fixed");
  __ bind(_entry);
  ce->store_parameter(_obj_reg->as_register(),  1);
  ce->store_parameter(_lock_reg->as_register(), 0);
  Runtime1::StubID enter_id;
  if (ce->compilation()->has_fpu_code()) {
    enter_id = Runtime1::monitorenter_id;
  } else {
    enter_id = Runtime1::monitorenter_nofpu_id;
  }
  __ call(RuntimeAddress(Runtime1::entry_for(enter_id)));
  ce->add_call_info_here(_info);
  ce->verify_oop_map(_info);
  __ jmp(_continuation);
}


void MonitorExitStub::emit_code(LIR_Assembler* ce) {
  __ bind(_entry);
  if (_compute_lock) {
    // lock_reg was destroyed by fast unlocking attempt => recompute it
    ce->monitor_address(_monitor_ix, _lock_reg);
  }
  ce->store_parameter(_lock_reg->as_register(), 0);
  // note: non-blocking leaf routine => no call info needed
  Runtime1::StubID exit_id;
  if (ce->compilation()->has_fpu_code()) {
    exit_id = Runtime1::monitorexit_id;
  } else {
    exit_id = Runtime1::monitorexit_nofpu_id;
  }
  __ call(RuntimeAddress(Runtime1::entry_for(exit_id)));
  __ jmp(_continuation);
}


// Implementation of patching:
// - Copy the code at given offset to an inlined buffer (first the bytes, then the number of bytes)
// - Replace original code with a call to the stub
// At Runtime:
// - call to stub, jump to runtime
// - in runtime: preserve all registers (rspecially objects, i.e., source and destination object)
// - in runtime: after initializing class, restore original code, reexecute instruction

int PatchingStub::_patch_info_offset = -NativeGeneralJump::instruction_size;

void PatchingStub::align_patch_site(MacroAssembler* masm) {
  // We're patching a 5-7 byte instruction on intel and we need to
  // make sure that we don't see a piece of the instruction.  It
  // appears mostly impossible on Intel to simply invalidate other
  // processors caches and since they may do aggressive prefetch it's
  // very hard to make a guess about what code might be in the icache.
  // Force the instruction to be double word aligned so that it
  // doesn't span a cache line.
  masm->align(round_to(NativeGeneralJump::instruction_size, wordSize));
}

void PatchingStub::emit_code(LIR_Assembler* ce) {
  assert(NativeCall::instruction_size <= _bytes_to_copy && _bytes_to_copy <= 0xFF, "not enough room for call");

  Label call_patch;

  // static field accesses have special semantics while the class
  // initializer is being run so we emit a test which can be used to
  // check that this code is being executed by the initializing
  // thread.
  address being_initialized_entry = __ pc();
  if (CommentedAssembly) {
    __ block_comment(" patch template");
  }
  if (_id == load_klass_id) {
    // produce a copy of the load klass instruction for use by the being initialized case
    address start = __ pc();
    jobject o = NULL;
    __ movoop(_obj, o);
#ifdef ASSERT
    for (int i = 0; i < _bytes_to_copy; i++) {
      address ptr = (address)(_pc_start + i);
      int a_byte = (*ptr) & 0xFF;
      assert(a_byte == *start++, "should be the same code");
    }
#endif
  } else {
    // make a copy the code which is going to be patched.
    for ( int i = 0; i < _bytes_to_copy; i++) {
      address ptr = (address)(_pc_start + i);
      int a_byte = (*ptr) & 0xFF;
      __ a_byte (a_byte);
      *ptr = 0x90; // make the site look like a nop
    }
  }

  address end_of_patch = __ pc();
  int bytes_to_skip = 0;
  if (_id == load_klass_id) {
    int offset = __ offset();
    if (CommentedAssembly) {
      __ block_comment(" being_initialized check");
    }
    assert(_obj != noreg, "must be a valid register");
    Register tmp = rax;
    if (_obj == tmp) tmp = rbx;
    __ push(tmp);
    __ get_thread(tmp);
    __ cmpptr(tmp, Address(_obj, instanceKlass::init_thread_offset_in_bytes() + sizeof(klassOopDesc)));
    __ pop(tmp);
    __ jcc(Assembler::notEqual, call_patch);

    // access_field patches may execute the patched code before it's
    // copied back into place so we need to jump back into the main
    // code of the nmethod to continue execution.
    __ jmp(_patch_site_continuation);

    // make sure this extra code gets skipped
    bytes_to_skip += __ offset() - offset;
  }
  if (CommentedAssembly) {
    __ block_comment("patch data encoded as movl");
  }
  // Now emit the patch record telling the runtime how to find the
  // pieces of the patch.  We only need 3 bytes but for readability of
  // the disassembly we make the data look like a movl reg, imm32,
  // which requires 5 bytes
  int sizeof_patch_record = 5;
  bytes_to_skip += sizeof_patch_record;

  // emit the offsets needed to find the code to patch
  int being_initialized_entry_offset = __ pc() - being_initialized_entry + sizeof_patch_record;

  __ a_byte(0xB8);
  __ a_byte(0);
  __ a_byte(being_initialized_entry_offset);
  __ a_byte(bytes_to_skip);
  __ a_byte(_bytes_to_copy);
  address patch_info_pc = __ pc();
  assert(patch_info_pc - end_of_patch == bytes_to_skip, "incorrect patch info");

  address entry = __ pc();
  NativeGeneralJump::insert_unconditional((address)_pc_start, entry);
  address target = NULL;
  switch (_id) {
    case access_field_id:  target = Runtime1::entry_for(Runtime1::access_field_patching_id); break;
    case load_klass_id:    target = Runtime1::entry_for(Runtime1::load_klass_patching_id); break;
    default: ShouldNotReachHere();
  }
  __ bind(call_patch);

  if (CommentedAssembly) {
    __ block_comment("patch entry point");
  }
  __ call(RuntimeAddress(target));
  assert(_patch_info_offset == (patch_info_pc - __ pc()), "must not change");
  ce->add_call_info_here(_info);
  int jmp_off = __ offset();
  __ jmp(_patch_site_entry);
  // Add enough nops so deoptimization can overwrite the jmp above with a call
  // and not destroy the world.
  for (int j = __ offset() ; j < jmp_off + 5 ; j++ ) {
    __ nop();
  }
  if (_id == load_klass_id) {
    CodeSection* cs = __ code_section();
    RelocIterator iter(cs, (address)_pc_start, (address)(_pc_start + 1));
    relocInfo::change_reloc_info_for_address(&iter, (address) _pc_start, relocInfo::oop_type, relocInfo::none);
  }
}


void ImplicitNullCheckStub::emit_code(LIR_Assembler* ce) {
  ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
  __ bind(_entry);
  __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::throw_null_pointer_exception_id)));
  ce->add_call_info_here(_info);
  debug_only(__ should_not_reach_here());
}


void SimpleExceptionStub::emit_code(LIR_Assembler* ce) {
  assert(__ rsp_offset() == 0, "frame size should be fixed");

  __ bind(_entry);
  // pass the object on stack because all registers must be preserved
  if (_obj->is_cpu_register()) {
    ce->store_parameter(_obj->as_register(), 0);
  }
  __ call(RuntimeAddress(Runtime1::entry_for(_stub)));
  ce->add_call_info_here(_info);
  debug_only(__ should_not_reach_here());
}


ArrayStoreExceptionStub::ArrayStoreExceptionStub(CodeEmitInfo* info):
  _info(info) {
}


void ArrayStoreExceptionStub::emit_code(LIR_Assembler* ce) {
  assert(__ rsp_offset() == 0, "frame size should be fixed");
  __ bind(_entry);
  __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::throw_array_store_exception_id)));
  ce->add_call_info_here(_info);
  debug_only(__ should_not_reach_here());
}


void ArrayCopyStub::emit_code(LIR_Assembler* ce) {
  //---------------slow case: call to native-----------------
  __ bind(_entry);
  // Figure out where the args should go
  // This should really convert the IntrinsicID to the methodOop and signature
  // but I don't know how to do that.
  //
  VMRegPair args[5];
  BasicType signature[5] = { T_OBJECT, T_INT, T_OBJECT, T_INT, T_INT};
  SharedRuntime::java_calling_convention(signature, args, 5, true);

  // push parameters
  // (src, src_pos, dest, destPos, length)
  Register r[5];
  r[0] = src()->as_register();
  r[1] = src_pos()->as_register();
  r[2] = dst()->as_register();
  r[3] = dst_pos()->as_register();
  r[4] = length()->as_register();

  // next registers will get stored on the stack
  for (int i = 0; i < 5 ; i++ ) {
    VMReg r_1 = args[i].first();
    if (r_1->is_stack()) {
      int st_off = r_1->reg2stack() * wordSize;
      __ movptr (Address(rsp, st_off), r[i]);
    } else {
      assert(r[i] == args[i].first()->as_Register(), "Wrong register for arg ");
    }
  }

  ce->align_call(lir_static_call);

  ce->emit_static_call_stub();
  AddressLiteral resolve(SharedRuntime::get_resolve_static_call_stub(),
                         relocInfo::static_call_type);
  __ call(resolve);
  ce->add_call_info_here(info());

#ifndef PRODUCT
  __ incrementl(ExternalAddress((address)&Runtime1::_arraycopy_slowcase_cnt));
#endif

  __ jmp(_continuation);
}

/////////////////////////////////////////////////////////////////////////////
#ifndef SERIALGC

void G1PreBarrierStub::emit_code(LIR_Assembler* ce) {

  // At this point we know that marking is in progress

  __ bind(_entry);
  assert(pre_val()->is_register(), "Precondition.");

  Register pre_val_reg = pre_val()->as_register();

  ce->mem2reg(addr(), pre_val(), T_OBJECT, patch_code(), info(), false);

  __ cmpptr(pre_val_reg, (int32_t) NULL_WORD);
  __ jcc(Assembler::equal, _continuation);
  ce->store_parameter(pre_val()->as_register(), 0);
  __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::g1_pre_barrier_slow_id)));
  __ jmp(_continuation);

}

jbyte* G1PostBarrierStub::_byte_map_base = NULL;

jbyte* G1PostBarrierStub::byte_map_base_slow() {
  BarrierSet* bs = Universe::heap()->barrier_set();
  assert(bs->is_a(BarrierSet::G1SATBCTLogging),
         "Must be if we're using this.");
  return ((G1SATBCardTableModRefBS*)bs)->byte_map_base;
}

void G1PostBarrierStub::emit_code(LIR_Assembler* ce) {
  __ bind(_entry);
  assert(addr()->is_register(), "Precondition.");
  assert(new_val()->is_register(), "Precondition.");
  Register new_val_reg = new_val()->as_register();
  __ cmpptr(new_val_reg, (int32_t) NULL_WORD);
  __ jcc(Assembler::equal, _continuation);
  ce->store_parameter(addr()->as_register(), 0);
  __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::g1_post_barrier_slow_id)));
  __ jmp(_continuation);
}

#endif // SERIALGC
/////////////////////////////////////////////////////////////////////////////

#undef __