1 /*
2 * Copyright (c) 1999, 2018, 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 #include "asm/macroAssembler.inline.hpp"
27 #include "c1/c1_MacroAssembler.hpp"
28 #include "c1/c1_Runtime1.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "gc/shared/collectedHeap.hpp"
31 #include "interpreter/interpreter.hpp"
32 #include "oops/arrayOop.hpp"
33 #include "oops/markWord.hpp"
34 #include "runtime/basicLock.hpp"
35 #include "runtime/biasedLocking.hpp"
36 #include "runtime/os.hpp"
37 #include "runtime/sharedRuntime.hpp"
38 #include "runtime/stubRoutines.hpp"
39
40 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
41 Label L;
42 const Register temp_reg = G3_scratch;
43 // Note: needs more testing of out-of-line vs. inline slow case
44 verify_oop(receiver);
45 load_klass(receiver, temp_reg);
46 cmp_and_brx_short(temp_reg, iCache, Assembler::equal, Assembler::pt, L);
47 AddressLiteral ic_miss(SharedRuntime::get_ic_miss_stub());
48 jump_to(ic_miss, temp_reg);
49 delayed()->nop();
50 align(CodeEntryAlignment);
51 bind(L);
52 }
53
54
55 void C1_MacroAssembler::explicit_null_check(Register base) {
56 Unimplemented();
57 }
58
59
60 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) {
61 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
62 generate_stack_overflow_check(bang_size_in_bytes);
63 // Create the frame.
64 save_frame_c1(frame_size_in_bytes);
65 }
66
67
68 void C1_MacroAssembler::verified_entry() {
69 if (C1Breakpoint) {
70 breakpoint_trap();
71 }
72 }
73
74
75 void C1_MacroAssembler::lock_object(Register Rmark, Register Roop, Register Rbox, Register Rscratch, Label& slow_case) {
76 assert_different_registers(Rmark, Roop, Rbox, Rscratch);
77
78 Label done;
79
80 Address mark_addr(Roop, oopDesc::mark_offset_in_bytes());
81
82 // The following move must be the first instruction of emitted since debug
83 // information may be generated for it.
84 // Load object header
85 ld_ptr(mark_addr, Rmark);
86
87 verify_oop(Roop);
88
89 // save object being locked into the BasicObjectLock
90 st_ptr(Roop, Rbox, BasicObjectLock::obj_offset_in_bytes());
91
92 if (UseBiasedLocking) {
93 biased_locking_enter(Roop, Rmark, Rscratch, done, &slow_case);
94 }
95
96 // Save Rbox in Rscratch to be used for the cas operation
97 mov(Rbox, Rscratch);
98
99 // and mark it unlocked
100 or3(Rmark, markWord::unlocked_value, Rmark);
101
102 // save unlocked object header into the displaced header location on the stack
103 st_ptr(Rmark, Rbox, BasicLock::displaced_header_offset_in_bytes());
104
105 // compare object markWord with Rmark and if equal exchange Rscratch with object markWord
106 assert(mark_addr.disp() == 0, "cas must take a zero displacement");
107 cas_ptr(mark_addr.base(), Rmark, Rscratch);
108 // if compare/exchange succeeded we found an unlocked object and we now have locked it
109 // hence we are done
110 cmp(Rmark, Rscratch);
111 brx(Assembler::equal, false, Assembler::pt, done);
112 delayed()->sub(Rscratch, SP, Rscratch); //pull next instruction into delay slot
113 // we did not find an unlocked object so see if this is a recursive case
114 // sub(Rscratch, SP, Rscratch);
115 assert(os::vm_page_size() > 0xfff, "page size too small - change the constant");
116 andcc(Rscratch, 0xfffff003, Rscratch);
117 brx(Assembler::notZero, false, Assembler::pn, slow_case);
118 delayed()->st_ptr(Rscratch, Rbox, BasicLock::displaced_header_offset_in_bytes());
119 bind(done);
120 }
121
122
123 void C1_MacroAssembler::unlock_object(Register Rmark, Register Roop, Register Rbox, Label& slow_case) {
124 assert_different_registers(Rmark, Roop, Rbox);
125
126 Label done;
127
128 Address mark_addr(Roop, oopDesc::mark_offset_in_bytes());
129 assert(mark_addr.disp() == 0, "cas must take a zero displacement");
130
131 if (UseBiasedLocking) {
132 // load the object out of the BasicObjectLock
133 ld_ptr(Rbox, BasicObjectLock::obj_offset_in_bytes(), Roop);
134 verify_oop(Roop);
135 biased_locking_exit(mark_addr, Rmark, done);
136 }
137 // Test first it it is a fast recursive unlock
138 ld_ptr(Rbox, BasicLock::displaced_header_offset_in_bytes(), Rmark);
139 br_null_short(Rmark, Assembler::pt, done);
140 if (!UseBiasedLocking) {
141 // load object
142 ld_ptr(Rbox, BasicObjectLock::obj_offset_in_bytes(), Roop);
143 verify_oop(Roop);
144 }
145
146 // Check if it is still a light weight lock, this is is true if we see
147 // the stack address of the basicLock in the markWord of the object
148 cas_ptr(mark_addr.base(), Rbox, Rmark);
149 cmp(Rbox, Rmark);
150
151 brx(Assembler::notEqual, false, Assembler::pn, slow_case);
152 delayed()->nop();
153 // Done
154 bind(done);
155 }
156
157
158 void C1_MacroAssembler::try_allocate(
159 Register obj, // result: pointer to object after successful allocation
160 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise
161 int con_size_in_bytes, // object size in bytes if known at compile time
162 Register t1, // temp register, must be global register for incr_allocated_bytes
163 Register t2, // temp register
164 Label& slow_case // continuation point if fast allocation fails
165 ) {
166 RegisterOrConstant size_in_bytes = var_size_in_bytes->is_valid()
167 ? RegisterOrConstant(var_size_in_bytes) : RegisterOrConstant(con_size_in_bytes);
168 if (UseTLAB) {
169 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
170 } else {
171 eden_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
172 incr_allocated_bytes(size_in_bytes, t1, t2);
173 }
174 }
175
176
177 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
178 assert_different_registers(obj, klass, len, t1, t2);
179 if (UseBiasedLocking && !len->is_valid()) {
180 ld_ptr(klass, in_bytes(Klass::prototype_header_offset()), t1);
181 } else {
182 set((intx)markWord::prototype().value(), t1);
183 }
184 st_ptr(t1, obj, oopDesc::mark_offset_in_bytes());
185 if (UseCompressedClassPointers) {
186 // Save klass
187 mov(klass, t1);
188 encode_klass_not_null(t1);
189 stw(t1, obj, oopDesc::klass_offset_in_bytes());
190 } else {
191 st_ptr(klass, obj, oopDesc::klass_offset_in_bytes());
192 }
193 if (len->is_valid()) {
194 st(len, obj, arrayOopDesc::length_offset_in_bytes());
195 } else if (UseCompressedClassPointers) {
196 // otherwise length is in the class gap
197 store_klass_gap(G0, obj);
198 }
199 }
200
201
202 void C1_MacroAssembler::initialize_body(Register base, Register index) {
203 zero_memory(base, index);
204 }
205
206
207 void C1_MacroAssembler::allocate_object(
208 Register obj, // result: pointer to object after successful allocation
209 Register t1, // temp register
210 Register t2, // temp register, must be a global register for try_allocate
211 Register t3, // temp register
212 int hdr_size, // object header size in words
213 int obj_size, // object size in words
214 Register klass, // object klass
215 Label& slow_case // continuation point if fast allocation fails
216 ) {
217 assert_different_registers(obj, t1, t2, t3, klass);
218 assert(klass == G5, "must be G5");
219
220 // allocate space & initialize header
221 if (!is_simm13(obj_size * wordSize)) {
222 // would need to use extra register to load
223 // object size => go the slow case for now
224 ba(slow_case);
225 delayed()->nop();
226 return;
227 }
228 try_allocate(obj, noreg, obj_size * wordSize, t2, t3, slow_case);
229
230 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2, /* is_tlab_allocated */ UseTLAB);
231 }
232
233 void C1_MacroAssembler::initialize_object(
234 Register obj, // result: pointer to object after successful allocation
235 Register klass, // object klass
236 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise
237 int con_size_in_bytes, // object size in bytes if known at compile time
238 Register t1, // temp register
239 Register t2, // temp register
240 bool is_tlab_allocated // the object was allocated in a TLAB; relevant for the implementation of ZeroTLAB
241 ) {
242 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
243
244 initialize_header(obj, klass, noreg, t1, t2);
245
246 #ifdef ASSERT
247 {
248 Label ok;
249 ld(klass, in_bytes(Klass::layout_helper_offset()), t1);
250 if (var_size_in_bytes != noreg) {
251 cmp_and_brx_short(t1, var_size_in_bytes, Assembler::equal, Assembler::pt, ok);
252 } else {
253 cmp_and_brx_short(t1, con_size_in_bytes, Assembler::equal, Assembler::pt, ok);
254 }
255 stop("bad size in initialize_object");
256 should_not_reach_here();
257
258 bind(ok);
259 }
260
261 #endif
262
263 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) {
264 // initialize body
265 const int threshold = 5 * HeapWordSize; // approximate break even point for code size
266 if (var_size_in_bytes != noreg) {
267 // use a loop
268 add(obj, hdr_size_in_bytes, t1); // compute address of first element
269 sub(var_size_in_bytes, hdr_size_in_bytes, t2); // compute size of body
270 initialize_body(t1, t2);
271 } else if (con_size_in_bytes <= threshold) {
272 // use explicit NULL stores
273 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += HeapWordSize) st_ptr(G0, obj, i);
274 } else if (con_size_in_bytes > hdr_size_in_bytes) {
275 // use a loop
276 const Register base = t1;
277 const Register index = t2;
278 add(obj, hdr_size_in_bytes, base); // compute address of first element
279 // compute index = number of words to clear
280 set(con_size_in_bytes - hdr_size_in_bytes, index);
281 initialize_body(base, index);
282 }
283 }
284
285 if (CURRENT_ENV->dtrace_alloc_probes()) {
286 assert(obj == O0, "must be");
287 call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)),
288 relocInfo::runtime_call_type);
289 delayed()->nop();
290 }
291
292 verify_oop(obj);
293 }
294
295
296 void C1_MacroAssembler::allocate_array(
297 Register obj, // result: pointer to array after successful allocation
298 Register len, // array length
299 Register t1, // temp register
300 Register t2, // temp register
301 Register t3, // temp register
302 int hdr_size, // object header size in words
303 int elt_size, // element size in bytes
304 Register klass, // object klass
305 Label& slow_case // continuation point if fast allocation fails
306 ) {
307 assert_different_registers(obj, len, t1, t2, t3, klass);
308 assert(klass == G5, "must be G5");
309 assert(t1 == G1, "must be G1");
310
311 // determine alignment mask
312 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
313
314 // check for negative or excessive length
315 // note: the maximum length allowed is chosen so that arrays of any
316 // element size with this length are always smaller or equal
317 // to the largest integer (i.e., array size computation will
318 // not overflow)
319 set(max_array_allocation_length, t1);
320 cmp(len, t1);
321 br(Assembler::greaterUnsigned, false, Assembler::pn, slow_case);
322
323 // compute array size
324 // note: if 0 <= len <= max_length, len*elt_size + header + alignment is
325 // smaller or equal to the largest integer; also, since top is always
326 // aligned, we can do the alignment here instead of at the end address
327 // computation
328 const Register arr_size = t1;
329 switch (elt_size) {
330 case 1: delayed()->mov(len, arr_size); break;
331 case 2: delayed()->sll(len, 1, arr_size); break;
332 case 4: delayed()->sll(len, 2, arr_size); break;
333 case 8: delayed()->sll(len, 3, arr_size); break;
334 default: ShouldNotReachHere();
335 }
336 add(arr_size, hdr_size * wordSize + MinObjAlignmentInBytesMask, arr_size); // add space for header & alignment
337 and3(arr_size, ~MinObjAlignmentInBytesMask, arr_size); // align array size
338
339 // allocate space & initialize header
340 if (UseTLAB) {
341 tlab_allocate(obj, arr_size, 0, t2, slow_case);
342 } else {
343 eden_allocate(obj, arr_size, 0, t2, t3, slow_case);
344 }
345 initialize_header(obj, klass, len, t2, t3);
346
347 // initialize body
348 const Register base = t2;
349 const Register index = t3;
350 add(obj, hdr_size * wordSize, base); // compute address of first element
351 sub(arr_size, hdr_size * wordSize, index); // compute index = number of words to clear
352 initialize_body(base, index);
353
354 if (CURRENT_ENV->dtrace_alloc_probes()) {
355 assert(obj == O0, "must be");
356 call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)),
357 relocInfo::runtime_call_type);
358 delayed()->nop();
359 }
360
361 verify_oop(obj);
362 }
363
364
365 #ifndef PRODUCT
366
367 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
368 if (!VerifyOops) return;
369 verify_oop_addr(Address(SP, stack_offset + STACK_BIAS));
370 }
371
372 void C1_MacroAssembler::verify_not_null_oop(Register r) {
373 Label not_null;
374 br_notnull_short(r, Assembler::pt, not_null);
375 stop("non-null oop required");
376 bind(not_null);
377 if (!VerifyOops) return;
378 verify_oop(r);
379 }
380
381 void C1_MacroAssembler::invalidate_registers(bool iregisters, bool lregisters, bool oregisters,
382 Register preserve1, Register preserve2) {
383 if (iregisters) {
384 for (int i = 0; i < 6; i++) {
385 Register r = as_iRegister(i);
386 if (r != preserve1 && r != preserve2) set(0xdead, r);
387 }
388 }
389 if (oregisters) {
390 for (int i = 0; i < 6; i++) {
391 Register r = as_oRegister(i);
392 if (r != preserve1 && r != preserve2) set(0xdead, r);
393 }
394 }
395 if (lregisters) {
396 for (int i = 0; i < 8; i++) {
397 Register r = as_lRegister(i);
398 if (r != preserve1 && r != preserve2) set(0xdead, r);
399 }
400 }
401 }
402
403
404 #endif