duke@435: /*
xdono@1014:  * Copyright 1998-2009 Sun Microsystems, Inc.  All Rights Reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
duke@435:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435:  * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435:  * have any questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: 
duke@435: #include "incls/_precompiled.incl"
duke@435: #include "incls/_runtime_x86_32.cpp.incl"
duke@435: 
duke@435: #define __ masm->
duke@435: 
duke@435: ExceptionBlob*     OptoRuntime::_exception_blob;
duke@435: 
duke@435: //------------------------------generate_exception_blob---------------------------
duke@435: // creates exception blob at the end
duke@435: // Using exception blob, this code is jumped from a compiled method.
duke@435: //
duke@435: // Given an exception pc at a call we call into the runtime for the
duke@435: // handler in this method. This handler might merely restore state
duke@435: // (i.e. callee save registers) unwind the frame and jump to the
duke@435: // exception handler for the nmethod if there is no Java level handler
duke@435: // for the nmethod.
duke@435: //
duke@435: // This code is entered with a jmp.
duke@435: //
duke@435: // Arguments:
twisti@1570: //   rax: exception oop
duke@435: //   rdx: exception pc
duke@435: //
duke@435: // Results:
twisti@1570: //   rax: exception oop
duke@435: //   rdx: exception pc in caller or ???
duke@435: //   destination: exception handler of caller
duke@435: //
duke@435: // Note: the exception pc MUST be at a call (precise debug information)
duke@435: //       Only register rax, rdx, rcx are not callee saved.
duke@435: //
duke@435: 
duke@435: void OptoRuntime::generate_exception_blob() {
duke@435: 
duke@435:   // Capture info about frame layout
duke@435:   enum layout {
duke@435:     thread_off,                 // last_java_sp
duke@435:     // The frame sender code expects that rbp will be in the "natural" place and
duke@435:     // will override any oopMap setting for it. We must therefore force the layout
duke@435:     // so that it agrees with the frame sender code.
duke@435:     rbp_off,
duke@435:     return_off,                 // slot for return address
duke@435:     framesize
duke@435:   };
duke@435: 
duke@435:   // allocate space for the code
duke@435:   ResourceMark rm;
duke@435:   // setup code generation tools
duke@435:   CodeBuffer   buffer("exception_blob", 512, 512);
duke@435:   MacroAssembler* masm = new MacroAssembler(&buffer);
duke@435: 
duke@435:   OopMapSet *oop_maps = new OopMapSet();
duke@435: 
duke@435:   address start = __ pc();
duke@435: 
never@739:   __ push(rdx);
never@739:   __ subptr(rsp, return_off * wordSize);   // Prolog!
duke@435: 
duke@435:   // rbp, location is implicitly known
never@739:   __ movptr(Address(rsp,rbp_off  *wordSize), rbp);
duke@435: 
duke@435:   // Store exception in Thread object. We cannot pass any arguments to the
duke@435:   // handle_exception call, since we do not want to make any assumption
duke@435:   // about the size of the frame where the exception happened in.
duke@435:   __ get_thread(rcx);
never@739:   __ movptr(Address(rcx, JavaThread::exception_oop_offset()), rax);
never@739:   __ movptr(Address(rcx, JavaThread::exception_pc_offset()),  rdx);
duke@435: 
duke@435:   // This call does all the hard work.  It checks if an exception handler
duke@435:   // exists in the method.
duke@435:   // If so, it returns the handler address.
duke@435:   // If not, it prepares for stack-unwinding, restoring the callee-save
duke@435:   // registers of the frame being removed.
duke@435:   //
never@739:   __ movptr(Address(rsp, thread_off * wordSize), rcx); // Thread is first argument
duke@435:   __ set_last_Java_frame(rcx, noreg, noreg, NULL);
duke@435: 
duke@435:   __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C)));
duke@435: 
duke@435:   // No registers to map, rbp is known implicitly
duke@435:   oop_maps->add_gc_map( __ pc() - start,  new OopMap( framesize, 0 ));
duke@435:   __ get_thread(rcx);
duke@435:   __ reset_last_Java_frame(rcx, false, false);
duke@435: 
duke@435:   // Restore callee-saved registers
never@739:   __ movptr(rbp, Address(rsp, rbp_off * wordSize));
duke@435: 
never@739:   __ addptr(rsp, return_off * wordSize);   // Epilog!
never@739:   __ pop(rdx); // Exception pc
duke@435: 
twisti@1570:   // rax: exception handler for given <exception oop/exception pc>
duke@435: 
twisti@1570:   // Restore SP from BP if the exception PC is a MethodHandle call.
twisti@1570:   __ cmpl(Address(rcx, JavaThread::is_method_handle_exception_offset()), 0);
twisti@1570:   __ cmovptr(Assembler::notEqual, rsp, rbp);
duke@435: 
duke@435:   // We have a handler in rax, (could be deopt blob)
duke@435:   // rdx - throwing pc, deopt blob will need it.
duke@435: 
never@739:   __ push(rax);
duke@435: 
duke@435:   // Get the exception
never@739:   __ movptr(rax, Address(rcx, JavaThread::exception_oop_offset()));
duke@435:   // Get the exception pc in case we are deoptimized
never@739:   __ movptr(rdx, Address(rcx, JavaThread::exception_pc_offset()));
duke@435: #ifdef ASSERT
xlu@947:   __ movptr(Address(rcx, JavaThread::exception_handler_pc_offset()), NULL_WORD);
xlu@947:   __ movptr(Address(rcx, JavaThread::exception_pc_offset()), NULL_WORD);
duke@435: #endif
duke@435:   // Clear the exception oop so GC no longer processes it as a root.
xlu@947:   __ movptr(Address(rcx, JavaThread::exception_oop_offset()), NULL_WORD);
duke@435: 
never@739:   __ pop(rcx);
duke@435: 
twisti@1570:   // rax: exception oop
duke@435:   // rcx: exception handler
duke@435:   // rdx: exception pc
duke@435:   __ jmp (rcx);
duke@435: 
duke@435:   // -------------
duke@435:   // make sure all code is generated
duke@435:   masm->flush();
duke@435: 
duke@435:   _exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize);
duke@435: }