runtime_sparc.cpp revision 1472:c18cbe5936b8 
1/*
2 * Copyright (c) 1998, 2009, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25#include "incls/_precompiled.incl"
26#include "incls/_runtime_sparc.cpp.incl"
27
28
29#define __ masm->
30
31ExceptionBlob      *OptoRuntime::_exception_blob;
32
33//------------------------------ generate_exception_blob ---------------------------
34// creates exception blob at the end
35// Using exception blob, this code is jumped from a compiled method.
36// (see emit_exception_handler in sparc.ad file)
37//
38// Given an exception pc at a call we call into the runtime for the
39// handler in this method. This handler might merely restore state
40// (i.e. callee save registers) unwind the frame and jump to the
41// exception handler for the nmethod if there is no Java level handler
42// for the nmethod.
43//
44// This code is entered with a jmp.
45//
46// Arguments:
47//   O0: exception oop
48//   O1: exception pc
49//
50// Results:
51//   O0: exception oop
52//   O1: exception pc in caller or ???
53//   destination: exception handler of caller
54//
55// Note: the exception pc MUST be at a call (precise debug information)
56//
57void OptoRuntime::generate_exception_blob() {
58  // allocate space for code
59  ResourceMark rm;
60  int pad = VerifyThread ? 256 : 0;// Extra slop space for more verify code
61
62  // setup code generation tools
63  // Measured 8/7/03 at 256 in 32bit debug build (no VerifyThread)
64  // Measured 8/7/03 at 528 in 32bit debug build (VerifyThread)
65  CodeBuffer buffer("exception_blob", 600+pad, 512);
66  MacroAssembler* masm     = new MacroAssembler(&buffer);
67
68  int framesize_in_bytes = __ total_frame_size_in_bytes(0);
69  int framesize_in_words = framesize_in_bytes / wordSize;
70  int framesize_in_slots = framesize_in_bytes / sizeof(jint);
71
72  Label L;
73
74  int start = __ offset();
75
76  __ verify_thread();
77  __ st_ptr(Oexception,  G2_thread, JavaThread::exception_oop_offset());
78  __ st_ptr(Oissuing_pc, G2_thread, JavaThread::exception_pc_offset());
79
80  // This call does all the hard work. It checks if an exception catch
81  // exists in the method.
82  // If so, it returns the handler address.
83  // If the nmethod has been deoptimized and it had a handler the handler
84  // address is the deopt blob unpack_with_exception entry.
85  //
86  // If no handler exists it prepares for stack-unwinding, restoring the callee-save
87  // registers of the frame being removed.
88  //
89  __ save_frame(0);
90
91  __ mov(G2_thread, O0);
92  __ set_last_Java_frame(SP, noreg);
93  __ save_thread(L7_thread_cache);
94
95  // This call can block at exit and nmethod can be deoptimized at that
96  // point. If the nmethod had a catch point we would jump to the
97  // now deoptimized catch point and fall thru the vanilla deopt
98  // path and lose the exception
99  // Sure would be simpler if this call didn't block!
100  __ call(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C), relocInfo::runtime_call_type);
101  __ delayed()->mov(L7_thread_cache, O0);
102
103  // Set an oopmap for the call site.  This oopmap will only be used if we
104  // are unwinding the stack.  Hence, all locations will be dead.
105  // Callee-saved registers will be the same as the frame above (i.e.,
106  // handle_exception_stub), since they were restored when we got the
107  // exception.
108
109  OopMapSet *oop_maps = new OopMapSet();
110  oop_maps->add_gc_map( __ offset()-start, new OopMap(framesize_in_slots, 0));
111
112  __ bind(L);
113  __ restore_thread(L7_thread_cache);
114  __ reset_last_Java_frame();
115
116  __ mov(O0, G3_scratch);             // Move handler address to temp
117  __ restore();
118
119  // G3_scratch contains handler address
120  // Since this may be the deopt blob we must set O7 to look like we returned
121  // from the original pc that threw the exception
122
123  __ ld_ptr(G2_thread, JavaThread::exception_pc_offset(), O7);
124  __ sub(O7, frame::pc_return_offset, O7);
125
126
127  assert(Assembler::is_simm13(in_bytes(JavaThread::exception_oop_offset())), "exception offset overflows simm13, following ld instruction cannot be in delay slot");
128  __ ld_ptr(G2_thread, JavaThread::exception_oop_offset(), Oexception); // O0
129#ifdef ASSERT
130  __ st_ptr(G0, G2_thread, JavaThread::exception_handler_pc_offset());
131  __ st_ptr(G0, G2_thread, JavaThread::exception_pc_offset());
132#endif
133  __ JMP(G3_scratch, 0);
134  // Clear the exception oop so GC no longer processes it as a root.
135  __ delayed()->st_ptr(G0, G2_thread, JavaThread::exception_oop_offset());
136
137  // -------------
138  // make sure all code is generated
139  masm->flush();
140
141  _exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize_in_words);
142}
143