/*
 * Copyright 2003-2008 Sun Microsystems, Inc.  All Rights Reserved.
 * Copyright 2010 Lemote.  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/_vtableStubs_mips.cpp.incl"

// machine-dependent part of VtableStubs: create VtableStub of correct size and
// initialize its code

#define __ masm->

#ifndef PRODUCT
extern "C" void bad_compiled_vtable_index(JavaThread* thread,
                                          oop receiver,
                                          int index);
#endif

// used by compiler only;  reciever in T0.
// used registers :
// T7 : receiver klass & method
// NOTE: If this code is used by the C1, the receiver_location is always 0.
// when reach here, receiver in T0, klass in T8
VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
	const int gs2_code_length = VtableStub::pd_code_size_limit(true);
	//VtableStub* s = new(gs2_code_length) VtableStub(true, vtable_index, receiver_location);
	//FIXME aoqi
	VtableStub* s = new(gs2_code_length) VtableStub(true, vtable_index);
	ResourceMark rm;
        CodeBuffer cb(s->entry_point(), gs2_code_length);
	MacroAssembler* masm = new MacroAssembler(&cb);
	Register t1 = T8, t2 = T7;
#ifndef PRODUCT
//#ifdef COMPILER2
	if (CountCompiledCalls) {
		__ move(AT, (int)SharedRuntime::nof_megamorphic_calls_addr());
	        __ lw(t1, AT , 0);	
		__ addiu(t1, t1, 1);
		__ sw(t1, AT,0);
	}
//#endif
#endif

     // get receiver (need to skip return address on top of stack)
     //assert(receiver_location == T0->as_VMReg(), "receiver expected in T0");
	
     // get receiver klass
	address npe_addr = __ pc();
	__ lw(t1, T0, oopDesc::klass_offset_in_bytes());
	// compute entry offset (in words)
	int entry_offset = instanceKlass::vtable_start_offset() + vtable_index*vtableEntry::size();
#ifndef PRODUCT
	if (DebugVtables) { 
		Label L;
		// check offset vs vtable length
		__ lw(t2, t1, instanceKlass::vtable_length_offset()*wordSize);
		assert(Assembler::is_simm16(vtable_index*vtableEntry::size()), "change this code");
		__ move(AT, vtable_index*vtableEntry::size());
		__ slt(AT, AT, t2);
		__ bne(AT, ZERO, L);
		__ delayed()->nop();
		__ move(A2, vtable_index);
		__ move(A1, A0);
		__ call_VM(noreg, CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), A1, A2);
		__ bind(L);
	}
#endif // PRODUCT
	// load methodOop and target address
	const Register method = T7;
	// __ movl(method, Address(eax, entry_offset*wordSize + vtableEntry::method_offset_in_bytes()));
	__ lw(method, t1,  entry_offset*wordSize + vtableEntry::method_offset_in_bytes()); 
	if (DebugVtables) { 
	      Label L;
	      __ beq(method, ZERO, L); 
	      __ delayed()->nop();
	      // __ cmpl(Address(method, methodOopDesc::from_compiled_offset()), NULL_WORD);
	      __ lw(AT, method,in_bytes(methodOopDesc::from_compiled_offset())); 
	      //__ jcc(Assembler::notZero, L);
	      __ bne(AT, ZERO, L);
              __ delayed()->nop();	
	      __ stop("Vtable entry is NULL");
	      __ bind(L);
      }
	// T8: receiver klass
	// T0: receiver
	// T7: methodOop
	// T9: entry
	address ame_addr = __ pc();
         __ lw(T9, method,in_bytes(methodOopDesc::from_compiled_offset()));	
         __ jr(T9);	
         __ delayed()->nop();	
	masm->flush();
	s->set_exception_points(npe_addr, ame_addr);
	return s;
}


// i am not sure which register to contain Interface, now i just assume A1. FIXME
// used registers : 
//	T1 T7
// when reach here, the receiver in T0, klass in T1
VtableStub* VtableStubs::create_itable_stub(int vtable_index) {
  // Note well: pd_code_size_limit is the absolute minimum we can get
  // away with.  If you add code here, bump the code stub size
  // returned by pd_code_size_limit!
   const int gs2_code_length = VtableStub::pd_code_size_limit(false);
   VtableStub* s = new(gs2_code_length) VtableStub(false, vtable_index);
   ResourceMark rm;
   CodeBuffer cb(s->entry_point(), gs2_code_length);
   MacroAssembler* masm = new MacroAssembler(&cb);
// we T8,T9 as temparary register, they are free from register allocator
     Register t1 = T8, t2 = T7;
	// Entry arguments:
	//  T1: Interface
	//  T0: Receiver
#ifndef PRODUCT
  if (CountCompiledCalls) {
	  //__ incl(Address((int)SharedRuntime::nof_megamorphic_calls_addr(), relocInfo::none));
            __ move(AT, (int)SharedRuntime::nof_megamorphic_calls_addr());
            __ lw(T8, AT, 0);
	    __ addi(T8, T8,1); 
            __ sw(T8, AT, 0);
  }
#endif /* PRODUCT */
	//assert(receiver_location == T0->as_VMReg(), "receiver expected in T0");
	// get receiver klass (also an implicit null-check)
	address npe_addr = __ pc();
	__ lw(t1, T0, oopDesc::klass_offset_in_bytes());
	// compute itable entry offset (in words)  
	const int base = instanceKlass::vtable_start_offset() * wordSize;    
	assert(vtableEntry::size() * wordSize == 4, "adjust the scaling in the code below");
	assert(Assembler::is_simm16(base), "change this code");
	__ addi(t2, t1, base);
	assert(Assembler::is_simm16(instanceKlass::vtable_length_offset() * wordSize), "change this code");
	__ lw(AT, t1, instanceKlass::vtable_length_offset() * wordSize);
	__ shl(AT, 2);
	__ add(t2, t2, AT);
	if (HeapWordsPerLong > 1) {
		__ round_to(t2, BytesPerLong);
	}

	Label hit, entry;
   	assert(Assembler::is_simm16(itableOffsetEntry::size() * wordSize), "change this code");
	__ bind(entry);

#ifdef ASSERT
	// Check that the entry is non-null
	if (DebugVtables) { 
		Label L;
		assert(Assembler::is_simm16(itableOffsetEntry::interface_offset_in_bytes()), "change this code");
		__ lw(AT, t1, itableOffsetEntry::interface_offset_in_bytes());
		__ bne(AT, ZERO, L);
		__ delayed()->nop();
		__ stop("null entry point found in itable's offset table");
		__ bind(L);
	}
#endif
	assert(Assembler::is_simm16(itableOffsetEntry::interface_offset_in_bytes()), "change this code");
	__ lw(AT, t2, itableOffsetEntry::interface_offset_in_bytes());
	__ bne(AT, T1, entry);
	__ delayed()->addi(t2, t2, itableOffsetEntry::size() * wordSize);

	// We found a hit, move offset into T9
	__ lw(t2, t2, itableOffsetEntry::offset_offset_in_bytes() - itableOffsetEntry::size() * wordSize);

	// Compute itableMethodEntry.  
	const int method_offset = (itableMethodEntry::size() * wordSize * vtable_index) + 
		itableMethodEntry::method_offset_in_bytes();

  // Get methodOop and entrypoint for compiler    
//  const Register method = ebx;
      const Register method = T7;
//   __ movl(method, Address(esi, edx, Address::times_1, method_offset));  
      __ sll(AT, t2, Address::times_1); 
      __ add(AT, AT, t1 );  
      __ lw(method, AT,  method_offset);  


	
#ifdef ASSERT
	if (DebugVtables) {
		Label L1;
	//      __ cmpl(method, NULL_WORD);
 //     __ jcc(Assembler::equal, L1);
        __ beq(method, ZERO, L1); 
        __ delayed()->nop();		
//	__ cmpl(Address(method, methodOopDesc::from_compiled_offset()), NULL_WORD);
        __ lw(AT, method,in_bytes(methodOopDesc::from_compiled_offset())); 
//	__ jcc(Assembler::notZero, L1);
        __ bne(AT, ZERO, L1); 
        __ delayed()->nop();
	__ stop("methodOop is null");
	__ bind(L1);
	}
#endif // ASSERT
/*
	// T7: methodOop
	// T0: receiver
	// T9: entry point      
	__ jmp(T9);
#endif // COMPILER2
*/
        address ame_addr = __ pc();
	//__ jmp(Address(method, methodOopDesc::from_compiled_offset()));
        __ lw(T9, method,in_bytes(methodOopDesc::from_compiled_offset()));
        __ jr(T9);
        __ delayed()->nop();	
    masm->flush();
	s->set_exception_points(npe_addr, ame_addr);
	return s;
}

// NOTE : whenever you change the code above, dont forget to change the const here
int VtableStub::pd_code_size_limit(bool is_vtable_stub) {
	if (is_vtable_stub) {
            return ( DebugVtables ? 600 : 28) + (CountCompiledCalls ? 24 : 0);
	} else {
            return  ( DebugVtables ? 636 : 72) + (CountCompiledCalls ? 24 : 0);
	}
}

int VtableStub::pd_code_alignment() {
  return wordSize;
}