1 /*
2 * Copyright (c) 2010, 2011, 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 // Platform-specific definitions for method handles.
26 // These definitions are inlined into class MethodHandles.
27
28 // Adapters
29 enum /* platform_dependent_constants */ {
30 adapter_code_size = NOT_LP64(30000 DEBUG_ONLY(+ 10000)) LP64_ONLY(80000 DEBUG_ONLY(+ 120000))
31 };
32
33 public:
34
35 // The stack just after the recursive call from a ricochet frame
36 // looks something like this. Offsets are marked in words, not bytes.
37 // rsi (r13 on LP64) is part of the interpreter calling sequence
38 // which tells the callee where is my real rsp (for frame walking).
39 // (...lower memory addresses)
40 // rsp: [ return pc ] always the global RicochetBlob::bounce_addr
41 // rsp+1: [ recursive arg N ]
42 // rsp+2: [ recursive arg N-1 ]
43 // ...
44 // rsp+N: [ recursive arg 1 ]
45 // rsp+N+1: [ recursive method handle ]
46 // ...
47 // rbp-6: [ cleanup continuation pc ] <-- (struct RicochetFrame)
48 // rbp-5: [ saved target MH ] the MH we will call on the saved args
49 // rbp-4: [ saved args layout oop ] an int[] array which describes argument layout
50 // rbp-3: [ saved args pointer ] address of transformed adapter arg M (slot 0)
51 // rbp-2: [ conversion ] information about how the return value is used
52 // rbp-1: [ exact sender sp ] exact TOS (rsi/r13) of original sender frame
53 // rbp+0: [ saved sender fp ] (for original sender of AMH)
54 // rbp+1: [ saved sender pc ] (back to original sender of AMH)
55 // rbp+2: [ transformed adapter arg M ] <-- (extended TOS of original sender)
56 // rbp+3: [ transformed adapter arg M-1]
57 // ...
58 // rbp+M+1: [ transformed adapter arg 1 ]
59 // rbp+M+2: [ padding ] <-- (rbp + saved args base offset)
60 // ... [ optional padding]
61 // (higher memory addresses...)
62 //
63 // The arguments originally passed by the original sender
64 // are lost, and arbitrary amounts of stack motion might have
65 // happened due to argument transformation.
66 // (This is done by C2I/I2C adapters and non-direct method handles.)
67 // This is why there is an unpredictable amount of memory between
68 // the extended and exact TOS of the sender.
69 // The ricochet adapter itself will also (in general) perform
70 // transformations before the recursive call.
71 //
72 // The transformed and saved arguments, immediately above the saved
73 // return PC, are a well-formed method handle invocation ready to execute.
74 // When the GC needs to walk the stack, these arguments are described
75 // via the saved arg types oop, an int[] array with a private format.
76 // This array is derived from the type of the transformed adapter
77 // method handle, which also sits at the base of the saved argument
78 // bundle. Since the GC may not be able to fish out the int[]
79 // array, so it is pushed explicitly on the stack. This may be
80 // an unnecessary expense.
81 //
82 // The following register conventions are significant at this point:
83 // rsp the thread stack, as always; preserved by caller
84 // rsi/r13 exact TOS of recursive frame (contents of [rbp-2])
85 // rcx recursive method handle (contents of [rsp+N+1])
86 // rbp preserved by caller (not used by caller)
87 // Unless otherwise specified, all registers can be blown by the call.
88 //
89 // If this frame must be walked, the transformed adapter arguments
90 // will be found with the help of the saved arguments descriptor.
91 //
92 // Therefore, the descriptor must match the referenced arguments.
93 // The arguments must be followed by at least one word of padding,
94 // which will be necessary to complete the final method handle call.
95 // That word is not treated as holding an oop. Neither is the word
96 //
97 // The word pointed to by the return argument pointer is not
98 // treated as an oop, even if points to a saved argument.
99 // This allows the saved argument list to have a "hole" in it
100 // to receive an oop from the recursive call.
101 // (The hole might temporarily contain RETURN_VALUE_PLACEHOLDER.)
102 //
103 // When the recursive callee returns, RicochetBlob::bounce_addr will
104 // immediately jump to the continuation stored in the RF.
105 // This continuation will merge the recursive return value
106 // into the saved argument list. At that point, the original
107 // rsi, rbp, and rsp will be reloaded, the ricochet frame will
108 // disappear, and the final target of the adapter method handle
109 // will be invoked on the transformed argument list.
110
111 class RicochetFrame {
112 friend class MethodHandles;
113 friend class VMStructs;
114
115 private:
116 intptr_t* _continuation; // what to do when control gets back here
117 oopDesc* _saved_target; // target method handle to invoke on saved_args
118 oopDesc* _saved_args_layout; // caching point for MethodTypeForm.vmlayout cookie
119 intptr_t* _saved_args_base; // base of pushed arguments (slot 0, arg N) (-3)
120 intptr_t _conversion; // misc. information from original AdapterMethodHandle (-2)
121 intptr_t* _exact_sender_sp; // parallel to interpreter_frame_sender_sp (-1)
122 intptr_t* _sender_link; // *must* coincide with frame::link_offset (0)
123 address _sender_pc; // *must* coincide with frame::return_addr_offset (1)
124
125 public:
126 intptr_t* continuation() const { return _continuation; }
127 oop saved_target() const { return _saved_target; }
128 oop saved_args_layout() const { return _saved_args_layout; }
129 intptr_t* saved_args_base() const { return _saved_args_base; }
130 intptr_t conversion() const { return _conversion; }
131 intptr_t* exact_sender_sp() const { return _exact_sender_sp; }
132 intptr_t* sender_link() const { return _sender_link; }
133 address sender_pc() const { return _sender_pc; }
134
135 intptr_t* extended_sender_sp() const { return saved_args_base(); }
136
137 intptr_t return_value_slot_number() const {
138 return adapter_conversion_vminfo(conversion());
139 }
140 BasicType return_value_type() const {
141 return adapter_conversion_dest_type(conversion());
142 }
143 bool has_return_value_slot() const {
144 return return_value_type() != T_VOID;
145 }
146 intptr_t* return_value_slot_addr() const {
147 assert(has_return_value_slot(), "");
148 return saved_arg_slot_addr(return_value_slot_number());
149 }
150 intptr_t* saved_target_slot_addr() const {
151 return saved_arg_slot_addr(saved_args_length());
152 }
153 intptr_t* saved_arg_slot_addr(int slot) const {
154 assert(slot >= 0, "");
155 return (intptr_t*)( (address)saved_args_base() + (slot * Interpreter::stackElementSize) );
156 }
157
158 jint saved_args_length() const;
159 jint saved_arg_offset(int arg) const;
160
161 // GC interface
162 oop* saved_target_addr() { return (oop*)&_saved_target; }
163 oop* saved_args_layout_addr() { return (oop*)&_saved_args_layout; }
164
165 oop compute_saved_args_layout(bool read_cache, bool write_cache);
166
167 // Compiler/assembler interface.
168 static int continuation_offset_in_bytes() { return offset_of(RicochetFrame, _continuation); }
169 static int saved_target_offset_in_bytes() { return offset_of(RicochetFrame, _saved_target); }
170 static int saved_args_layout_offset_in_bytes(){ return offset_of(RicochetFrame, _saved_args_layout); }
171 static int saved_args_base_offset_in_bytes() { return offset_of(RicochetFrame, _saved_args_base); }
172 static int conversion_offset_in_bytes() { return offset_of(RicochetFrame, _conversion); }
173 static int exact_sender_sp_offset_in_bytes() { return offset_of(RicochetFrame, _exact_sender_sp); }
174 static int sender_link_offset_in_bytes() { return offset_of(RicochetFrame, _sender_link); }
175 static int sender_pc_offset_in_bytes() { return offset_of(RicochetFrame, _sender_pc); }
176
177 // This value is not used for much, but it apparently must be nonzero.
178 static int frame_size_in_bytes() { return sender_link_offset_in_bytes(); }
179
180 #ifdef ASSERT
181 // The magic number is supposed to help find ricochet frames within the bytes of stack dumps.
182 enum { MAGIC_NUMBER_1 = 0xFEED03E, MAGIC_NUMBER_2 = 0xBEEF03E };
183 static int magic_number_1_offset_in_bytes() { return -wordSize; }
184 static int magic_number_2_offset_in_bytes() { return sizeof(RicochetFrame); }
185 intptr_t magic_number_1() const { return *(intptr_t*)((address)this + magic_number_1_offset_in_bytes()); };
186 intptr_t magic_number_2() const { return *(intptr_t*)((address)this + magic_number_2_offset_in_bytes()); };
187 #endif //ASSERT
188
189 enum { RETURN_VALUE_PLACEHOLDER = (NOT_DEBUG(0) DEBUG_ONLY(42)) };
190
191 static void verify_offsets() NOT_DEBUG_RETURN;
192 void verify() const NOT_DEBUG_RETURN; // check for MAGIC_NUMBER, etc.
193 void zap_arguments() NOT_DEBUG_RETURN;
194
195 static void generate_ricochet_blob(MacroAssembler* _masm,
196 // output params:
197 int* bounce_offset,
198 int* exception_offset,
199 int* frame_size_in_words);
200
201 static void enter_ricochet_frame(MacroAssembler* _masm,
202 Register rcx_recv,
203 Register rax_argv,
204 address return_handler,
205 Register rbx_temp);
206 static void leave_ricochet_frame(MacroAssembler* _masm,
207 Register rcx_recv,
208 Register new_sp_reg,
209 Register sender_pc_reg);
210
211 static Address frame_address(int offset = 0) {
212 // The RicochetFrame is found by subtracting a constant offset from rbp.
213 return Address(rbp, - sender_link_offset_in_bytes() + offset);
214 }
215
216 static RicochetFrame* from_frame(const frame& fr) {
217 address bp = (address) fr.fp();
218 RicochetFrame* rf = (RicochetFrame*)(bp - sender_link_offset_in_bytes());
219 rf->verify();
220 return rf;
221 }
222
223 static void verify_clean(MacroAssembler* _masm) NOT_DEBUG_RETURN;
224 };
225
226 // Additional helper methods for MethodHandles code generation:
227 public:
228 static void load_klass_from_Class(MacroAssembler* _masm, Register klass_reg);
229 static void load_conversion_vminfo(MacroAssembler* _masm, Register reg, Address conversion_field_addr);
230 static void load_conversion_dest_type(MacroAssembler* _masm, Register reg, Address conversion_field_addr);
231
232 static void load_stack_move(MacroAssembler* _masm,
233 Register rdi_stack_move,
234 Register rcx_amh,
235 bool might_be_negative);
236
237 static void insert_arg_slots(MacroAssembler* _masm,
238 RegisterOrConstant arg_slots,
239 Register rax_argslot,
240 Register rbx_temp, Register rdx_temp);
241
242 static void remove_arg_slots(MacroAssembler* _masm,
243 RegisterOrConstant arg_slots,
244 Register rax_argslot,
245 Register rbx_temp, Register rdx_temp);
246
247 static void push_arg_slots(MacroAssembler* _masm,
248 Register rax_argslot,
249 RegisterOrConstant slot_count,
250 int skip_words_count,
251 Register rbx_temp, Register rdx_temp);
252
253 static void move_arg_slots_up(MacroAssembler* _masm,
254 Register rbx_bottom, // invariant
255 Address top_addr, // can use rax_temp
256 RegisterOrConstant positive_distance_in_slots,
257 Register rax_temp, Register rdx_temp);
258
259 static void move_arg_slots_down(MacroAssembler* _masm,
260 Address bottom_addr, // can use rax_temp
261 Register rbx_top, // invariant
262 RegisterOrConstant negative_distance_in_slots,
263 Register rax_temp, Register rdx_temp);
264
265 static void move_typed_arg(MacroAssembler* _masm,
266 BasicType type, bool is_element,
267 Address slot_dest, Address value_src,
268 Register rbx_temp, Register rdx_temp);
269
270 static void move_return_value(MacroAssembler* _masm, BasicType type,
271 Address return_slot);
272
273 static void verify_argslot(MacroAssembler* _masm, Register argslot_reg,
274 const char* error_message) NOT_DEBUG_RETURN;
275
276 static void verify_argslots(MacroAssembler* _masm,
277 RegisterOrConstant argslot_count,
278 Register argslot_reg,
279 bool negate_argslot,
280 const char* error_message) NOT_DEBUG_RETURN;
281
282 static void verify_stack_move(MacroAssembler* _masm,
283 RegisterOrConstant arg_slots,
284 int direction) NOT_DEBUG_RETURN;
285
286 static void verify_klass(MacroAssembler* _masm,
287 Register obj, KlassHandle klass,
288 const char* error_message = "wrong klass") NOT_DEBUG_RETURN;
289
290 static void verify_method_handle(MacroAssembler* _masm, Register mh_reg) {
291 verify_klass(_masm, mh_reg, SystemDictionaryHandles::MethodHandle_klass(),
292 "reference is a MH");
293 }
294
295 // Similar to InterpreterMacroAssembler::jump_from_interpreted.
296 // Takes care of special dispatch from single stepping too.
297 static void jump_from_method_handle(MacroAssembler* _masm, Register method, Register temp);
298
299 static void trace_method_handle(MacroAssembler* _masm, const char* adaptername) PRODUCT_RETURN;
300
301 static Register saved_last_sp_register() {
302 // Should be in sharedRuntime, not here.
303 return LP64_ONLY(r13) NOT_LP64(rsi);
304 }