1 /*
2 * Copyright (c) 2008, 2016, 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 "precompiled.hpp"
26 #ifdef COMPILER2
27 #include "asm/assembler.hpp"
28 #include "assembler_arm.inline.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "code/vmreg.hpp"
31 #include "interpreter/interpreter.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "nativeInst_arm.hpp"
34 #include "opto/runtime.hpp"
35 #include "runtime/interfaceSupport.inline.hpp"
36 #include "runtime/sharedRuntime.hpp"
37 #include "runtime/stubRoutines.hpp"
38 #include "runtime/vframeArray.hpp"
39 #include "utilities/globalDefinitions.hpp"
40 #include "vmreg_arm.inline.hpp"
41 #endif
42
43 #define __ masm->
44
45 //------------------------------ generate_exception_blob ---------------------------
46 // creates exception blob at the end
47 // Using exception blob, this code is jumped from a compiled method.
48 // (see emit_exception_handler in sparc.ad file)
49 //
50 // Given an exception pc at a call we call into the runtime for the
51 // handler in this method. This handler might merely restore state
52 // (i.e. callee save registers) unwind the frame and jump to the
53 // exception handler for the nmethod if there is no Java level handler
54 // for the nmethod.
55 //
56 // This code is entered with a jmp.
57 //
58 // Arguments:
59 // Rexception_obj (R4/R19): exception oop
60 // Rexception_pc (R5/R20): exception pc
61 //
62 // Results:
63 // Rexception_obj (R4/R19): exception oop
64 // O1: exception pc in caller or ???
65 // destination: exception handler of caller
66 //
67 // Note: the exception pc MUST be at a call (precise debug information)
68 //
generate_exception_blob()69 void OptoRuntime::generate_exception_blob() {
70 // allocate space for code
71 ResourceMark rm;
72 int pad = VerifyThread ? 256 : 0;// Extra slop space for more verify code
73
74 // setup code generation tools
75 // Measured 8/7/03 at 256 in 32bit debug build (no VerifyThread)
76 // Measured 8/7/03 at 528 in 32bit debug build (VerifyThread)
77 CodeBuffer buffer("exception_blob", 600+pad, 512);
78 MacroAssembler* masm = new MacroAssembler(&buffer);
79
80 int framesize_in_words = 2; // FP + LR
81 int framesize_in_bytes = framesize_in_words * wordSize;
82 int framesize_in_slots = framesize_in_bytes / sizeof(jint);
83
84 int start = __ offset();
85
86 __ str(Rexception_obj, Address(Rthread, JavaThread::exception_oop_offset()));
87 __ str(Rexception_pc, Address(Rthread, JavaThread::exception_pc_offset()));
88
89 // This call does all the hard work. It checks if an exception catch
90 // exists in the method.
91 // If so, it returns the handler address.
92 // If the nmethod has been deoptimized and it had a handler the handler
93 // address is the deopt blob unpack_with_exception entry.
94 //
95 // If no handler exists it prepares for stack-unwinding, restoring the callee-save
96 // registers of the frame being removed.
97 //
98 __ mov(LR, Rexception_pc);
99 __ raw_push(FP, LR);
100 int pc_offset = __ set_last_Java_frame(SP, FP, false, Rtemp);
101
102 __ mov(R0, Rthread);
103
104 // This call can block at exit and nmethod can be deoptimized at that
105 // point. If the nmethod had a catch point we would jump to the
106 // now deoptimized catch point and fall thru the vanilla deopt
107 // path and lose the exception
108 // Sure would be simpler if this call didn't block!
109 __ call(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C));
110 if (pc_offset == -1) {
111 pc_offset = __ offset();
112 }
113
114 // Set an oopmap for the call site. This oopmap will only be used if we
115 // are unwinding the stack. Hence, all locations will be dead.
116 // Callee-saved registers will be the same as the frame above (i.e.,
117 // handle_exception_stub), since they were restored when we got the
118 // exception.
119
120 OopMapSet *oop_maps = new OopMapSet();
121 oop_maps->add_gc_map(pc_offset - start, new OopMap(framesize_in_slots, 0));
122
123 __ reset_last_Java_frame(Rtemp);
124
125 __ raw_pop(FP, LR);
126
127 // Restore SP from its saved reg (FP) if the exception PC is a MethodHandle call site.
128 __ ldr(Rtemp, Address(Rthread, JavaThread::is_method_handle_return_offset()));
129 __ cmp(Rtemp, 0);
130 __ mov(SP, Rmh_SP_save, ne);
131
132 // R0 contains handler address
133 // Since this may be the deopt blob we must set R5 to look like we returned
134 // from the original pc that threw the exception
135
136 __ ldr(Rexception_pc, Address(Rthread, JavaThread::exception_pc_offset())); // R5/R20
137
138 __ ldr(Rexception_obj, Address(Rthread, JavaThread::exception_oop_offset())); // R4/R19
139 __ mov(Rtemp, 0);
140 #ifdef ASSERT
141 __ str(Rtemp, Address(Rthread, JavaThread::exception_handler_pc_offset()));
142 __ str(Rtemp, Address(Rthread, JavaThread::exception_pc_offset()));
143 #endif
144 // Clear the exception oop so GC no longer processes it as a root.
145 __ str(Rtemp, Address(Rthread, JavaThread::exception_oop_offset()));
146 __ jump(R0);
147
148 // -------------
149 // make sure all code is generated
150 masm->flush();
151
152 _exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize_in_words);
153 }
154