1 /*
2 * Copyright (c) 1998, 2010, 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
31 ExceptionBlob *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 //
57 void 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 // Restore SP from L7 if the exception PC is a MethodHandle call site.
120 __ lduw(Address(G2_thread, JavaThread::is_method_handle_return_offset()), O7);
121 __ tst(O7);
122 __ movcc(Assembler::notZero, false, Assembler::icc, L7_mh_SP_save, SP);
123
124 // G3_scratch contains handler address
125 // Since this may be the deopt blob we must set O7 to look like we returned
126 // from the original pc that threw the exception
127
128 __ ld_ptr(G2_thread, JavaThread::exception_pc_offset(), O7);
129 __ sub(O7, frame::pc_return_offset, O7);
130
131
132 assert(Assembler::is_simm13(in_bytes(JavaThread::exception_oop_offset())), "exception offset overflows simm13, following ld instruction cannot be in delay slot");
133 __ ld_ptr(G2_thread, JavaThread::exception_oop_offset(), Oexception); // O0
134 #ifdef ASSERT
135 __ st_ptr(G0, G2_thread, JavaThread::exception_handler_pc_offset());
136 __ st_ptr(G0, G2_thread, JavaThread::exception_pc_offset());
137 #endif
138 __ JMP(G3_scratch, 0);
139 // Clear the exception oop so GC no longer processes it as a root.
140 __ delayed()->st_ptr(G0, G2_thread, JavaThread::exception_oop_offset());
141
142 // -------------
143 // make sure all code is generated
144 masm->flush();
145
146 _exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize_in_words);
147 }