Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright 1998-2009 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/_runtime_x86_32.cpp.incl"

 #define __ masm->

 ExceptionBlob*     OptoRuntime::_exception_blob;

 //------------------------------generate_exception_blob---------------------------

 // creates exception blob at the end

 // Using exception blob, this code is jumped from a compiled method.

 //

 // Given an exception pc at a call we call into the runtime for the

 // handler in this method. This handler might merely restore state

 // (i.e. callee save registers) unwind the frame and jump to the

 // exception handler for the nmethod if there is no Java level handler

 // for the nmethod.

 //

 // This code is entered with a jmp.

 //

 // Arguments:

 //   rax,: exception oop

 //   rdx: exception pc

 //

 // Results:

 //   rax,: exception oop

 //   rdx: exception pc in caller or ???

 //   destination: exception handler of caller

 //

 // Note: the exception pc MUST be at a call (precise debug information)

 //       Only register rax, rdx, rcx are not callee saved.

 //

 void OptoRuntime::generate_exception_blob() {

   // Capture info about frame layout

   enum layout {

     thread_off,                 // last_java_sp

     // The frame sender code expects that rbp will be in the "natural" place and

     // will override any oopMap setting for it. We must therefore force the layout

     // so that it agrees with the frame sender code.

     rbp_off,

     return_off,                 // slot for return address

     framesize

   };

   // allocate space for the code

   ResourceMark rm;

   // setup code generation tools

   CodeBuffer   buffer("exception_blob", 512, 512);

   MacroAssembler* masm = new MacroAssembler(&buffer);

   OopMapSet *oop_maps = new OopMapSet();

   address start = __ pc();

   __ push(rdx);

   __ subptr(rsp, return_off * wordSize);   // Prolog!

   // rbp, location is implicitly known

   __ movptr(Address(rsp,rbp_off  *wordSize), rbp);

   // Store exception in Thread object. We cannot pass any arguments to the

   // handle_exception call, since we do not want to make any assumption

   // about the size of the frame where the exception happened in.

   __ get_thread(rcx);

   __ movptr(Address(rcx, JavaThread::exception_oop_offset()), rax);

   __ movptr(Address(rcx, JavaThread::exception_pc_offset()),  rdx);

   // This call does all the hard work.  It checks if an exception handler

   // exists in the method.

   // If so, it returns the handler address.

   // If not, it prepares for stack-unwinding, restoring the callee-save

   // registers of the frame being removed.

   //

   __ movptr(Address(rsp, thread_off * wordSize), rcx); // Thread is first argument

   __ set_last_Java_frame(rcx, noreg, noreg, NULL);

   __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C)));

   // No registers to map, rbp is known implicitly

   oop_maps->add_gc_map( __ pc() - start,  new OopMap( framesize, 0 ));

   __ get_thread(rcx);

   __ reset_last_Java_frame(rcx, false, false);

   // Restore callee-saved registers

   __ movptr(rbp, Address(rsp, rbp_off * wordSize));

   __ addptr(rsp, return_off * wordSize);   // Epilog!

   __ pop(rdx); // Exception pc

   // rax,: exception handler for given <exception oop/exception pc>

   // We have a handler in rax, (could be deopt blob)

   // rdx - throwing pc, deopt blob will need it.

   __ push(rax);

   // rcx contains handler address

   __ get_thread(rcx);           // TLS

   // Get the exception

   __ movptr(rax, Address(rcx, JavaThread::exception_oop_offset()));

   // Get the exception pc in case we are deoptimized

   __ movptr(rdx, Address(rcx, JavaThread::exception_pc_offset()));

 #ifdef ASSERT

   __ movptr(Address(rcx, JavaThread::exception_handler_pc_offset()), NULL_WORD);

   __ movptr(Address(rcx, JavaThread::exception_pc_offset()), NULL_WORD);

 #endif

   // Clear the exception oop so GC no longer processes it as a root.

   __ movptr(Address(rcx, JavaThread::exception_oop_offset()), NULL_WORD);

   __ pop(rcx);

   // rax,: exception oop

   // rcx: exception handler

   // rdx: exception pc

   __ jmp (rcx);

   // -------------

   // make sure all code is generated

   masm->flush();

   _exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize);

 }