1 /*
2 * Copyright (c) 1999, 2015, 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 "c1/c1_MacroAssembler.hpp"
27 #include "c1/c1_Runtime1.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "gc/shared/collectedHeap.hpp"
30 #include "interpreter/interpreter.hpp"
31 #include "oops/arrayOop.hpp"
32 #include "oops/markOop.hpp"
33 #include "runtime/basicLock.hpp"
34 #include "runtime/biasedLocking.hpp"
35 #include "runtime/os.hpp"
36 #include "runtime/sharedRuntime.hpp"
37 #include "runtime/stubRoutines.hpp"
38
39 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
40 Label L;
41 const Register temp_reg = G3_scratch;
42 // Note: needs more testing of out-of-line vs. inline slow case
43 verify_oop(receiver);
44 load_klass(receiver, temp_reg);
45 cmp_and_brx_short(temp_reg, iCache, Assembler::equal, Assembler::pt, L);
46 AddressLiteral ic_miss(SharedRuntime::get_ic_miss_stub());
47 jump_to(ic_miss, temp_reg);
48 delayed()->nop();
49 align(CodeEntryAlignment);
50 bind(L);
51 }
52
53
54 void C1_MacroAssembler::explicit_null_check(Register base) {
55 Unimplemented();
56 }
57
58
59 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) {
60 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
61 generate_stack_overflow_check(bang_size_in_bytes);
62 // Create the frame.
63 save_frame_c1(frame_size_in_bytes);
64 }
65
66
67 void C1_MacroAssembler::unverified_entry(Register receiver, Register ic_klass) {
68 if (C1Breakpoint) breakpoint_trap();
69 inline_cache_check(receiver, ic_klass);
70 }
71
72
73 void C1_MacroAssembler::verified_entry() {
74 if (C1Breakpoint) breakpoint_trap();
75 // build frame
76 verify_FPU(0, "method_entry");
77 }
78
79
80 void C1_MacroAssembler::lock_object(Register Rmark, Register Roop, Register Rbox, Register Rscratch, Label& slow_case) {
81 assert_different_registers(Rmark, Roop, Rbox, Rscratch);
82
83 Label done;
84
85 Address mark_addr(Roop, oopDesc::mark_offset_in_bytes());
86
87 // The following move must be the first instruction of emitted since debug
88 // information may be generated for it.
89 // Load object header
90 ld_ptr(mark_addr, Rmark);
91
92 verify_oop(Roop);
93
94 // save object being locked into the BasicObjectLock
95 st_ptr(Roop, Rbox, BasicObjectLock::obj_offset_in_bytes());
96
97 if (UseBiasedLocking) {
98 biased_locking_enter(Roop, Rmark, Rscratch, done, &slow_case);
99 }
100
101 // Save Rbox in Rscratch to be used for the cas operation
102 mov(Rbox, Rscratch);
103
104 // and mark it unlocked
105 or3(Rmark, markOopDesc::unlocked_value, Rmark);
106
107 // save unlocked object header into the displaced header location on the stack
108 st_ptr(Rmark, Rbox, BasicLock::displaced_header_offset_in_bytes());
109
110 // compare object markOop with Rmark and if equal exchange Rscratch with object markOop
111 assert(mark_addr.disp() == 0, "cas must take a zero displacement");
112 cas_ptr(mark_addr.base(), Rmark, Rscratch);
113 // if compare/exchange succeeded we found an unlocked object and we now have locked it
114 // hence we are done
115 cmp(Rmark, Rscratch);
116 brx(Assembler::equal, false, Assembler::pt, done);
117 delayed()->sub(Rscratch, SP, Rscratch); //pull next instruction into delay slot
118 // we did not find an unlocked object so see if this is a recursive case
119 // sub(Rscratch, SP, Rscratch);
120 assert(os::vm_page_size() > 0xfff, "page size too small - change the constant");
121 andcc(Rscratch, 0xfffff003, Rscratch);
122 brx(Assembler::notZero, false, Assembler::pn, slow_case);
123 delayed()->st_ptr(Rscratch, Rbox, BasicLock::displaced_header_offset_in_bytes());
124 bind(done);
125 }
126
127
128 void C1_MacroAssembler::unlock_object(Register Rmark, Register Roop, Register Rbox, Label& slow_case) {
129 assert_different_registers(Rmark, Roop, Rbox);
130
131 Label done;
132
133 Address mark_addr(Roop, oopDesc::mark_offset_in_bytes());
134 assert(mark_addr.disp() == 0, "cas must take a zero displacement");
135
136 if (UseBiasedLocking) {
137 // load the object out of the BasicObjectLock
138 ld_ptr(Rbox, BasicObjectLock::obj_offset_in_bytes(), Roop);
139 verify_oop(Roop);
140 biased_locking_exit(mark_addr, Rmark, done);
141 }
142 // Test first it it is a fast recursive unlock
143 ld_ptr(Rbox, BasicLock::displaced_header_offset_in_bytes(), Rmark);
144 br_null_short(Rmark, Assembler::pt, done);
145 if (!UseBiasedLocking) {
146 // load object
147 ld_ptr(Rbox, BasicObjectLock::obj_offset_in_bytes(), Roop);
148 verify_oop(Roop);
149 }
150
151 // Check if it is still a light weight lock, this is is true if we see
152 // the stack address of the basicLock in the markOop of the object
153 cas_ptr(mark_addr.base(), Rbox, Rmark);
154 cmp(Rbox, Rmark);
155
156 brx(Assembler::notEqual, false, Assembler::pn, slow_case);
157 delayed()->nop();
158 // Done
159 bind(done);
160 }
161
162
163 void C1_MacroAssembler::try_allocate(
164 Register obj, // result: pointer to object after successful allocation
165 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise
166 int con_size_in_bytes, // object size in bytes if known at compile time
167 Register t1, // temp register, must be global register for incr_allocated_bytes
168 Register t2, // temp register
169 Label& slow_case // continuation point if fast allocation fails
170 ) {
171 RegisterOrConstant size_in_bytes = var_size_in_bytes->is_valid()
172 ? RegisterOrConstant(var_size_in_bytes) : RegisterOrConstant(con_size_in_bytes);
173 if (UseTLAB) {
174 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
175 } else {
176 eden_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
177 incr_allocated_bytes(size_in_bytes, t1, t2);
178 }
179 }
180
181
182 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
183 assert_different_registers(obj, klass, len, t1, t2);
184 if (UseBiasedLocking && !len->is_valid()) {
185 ld_ptr(klass, in_bytes(Klass::prototype_header_offset()), t1);
186 } else {
187 set((intx)markOopDesc::prototype(), t1);
188 }
189 st_ptr(t1, obj, oopDesc::mark_offset_in_bytes());
190 if (UseCompressedClassPointers) {
191 // Save klass
192 mov(klass, t1);
193 encode_klass_not_null(t1);
194 stw(t1, obj, oopDesc::klass_offset_in_bytes());
195 } else {
196 st_ptr(klass, obj, oopDesc::klass_offset_in_bytes());
197 }
198 if (len->is_valid()) {
199 st(len, obj, arrayOopDesc::length_offset_in_bytes());
200 } else if (UseCompressedClassPointers) {
201 // otherwise length is in the class gap
202 store_klass_gap(G0, obj);
203 }
204 }
205
206
207 void C1_MacroAssembler::initialize_body(Register base, Register index) {
208 zero_memory(base, index);
209 }
210
211
212 void C1_MacroAssembler::allocate_object(
213 Register obj, // result: pointer to object after successful allocation
214 Register t1, // temp register
215 Register t2, // temp register, must be a global register for try_allocate
216 Register t3, // temp register
217 int hdr_size, // object header size in words
218 int obj_size, // object size in words
219 Register klass, // object klass
220 Label& slow_case // continuation point if fast allocation fails
221 ) {
222 assert_different_registers(obj, t1, t2, t3, klass);
223 assert(klass == G5, "must be G5");
224
225 // allocate space & initialize header
226 if (!is_simm13(obj_size * wordSize)) {
227 // would need to use extra register to load
228 // object size => go the slow case for now
229 ba(slow_case);
230 delayed()->nop();
231 return;
232 }
233 try_allocate(obj, noreg, obj_size * wordSize, t2, t3, slow_case);
234
235 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2, /* is_tlab_allocated */ UseTLAB);
236 }
237
238 void C1_MacroAssembler::initialize_object(
239 Register obj, // result: pointer to object after successful allocation
240 Register klass, // object klass
241 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise
242 int con_size_in_bytes, // object size in bytes if known at compile time
243 Register t1, // temp register
244 Register t2, // temp register
245 bool is_tlab_allocated // the object was allocated in a TLAB; relevant for the implementation of ZeroTLAB
246 ) {
247 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
248
249 initialize_header(obj, klass, noreg, t1, t2);
250
251 #ifdef ASSERT
252 {
253 Label ok;
254 ld(klass, in_bytes(Klass::layout_helper_offset()), t1);
255 if (var_size_in_bytes != noreg) {
256 cmp_and_brx_short(t1, var_size_in_bytes, Assembler::equal, Assembler::pt, ok);
257 } else {
258 cmp_and_brx_short(t1, con_size_in_bytes, Assembler::equal, Assembler::pt, ok);
259 }
260 stop("bad size in initialize_object");
261 should_not_reach_here();
262
263 bind(ok);
264 }
265
266 #endif
267
268 if (!(UseTLAB && ZeroTLAB && is_tlab_allocated)) {
269 // initialize body
270 const int threshold = 5 * HeapWordSize; // approximate break even point for code size
271 if (var_size_in_bytes != noreg) {
272 // use a loop
273 add(obj, hdr_size_in_bytes, t1); // compute address of first element
274 sub(var_size_in_bytes, hdr_size_in_bytes, t2); // compute size of body
275 initialize_body(t1, t2);
276 #ifndef _LP64
277 } else if (con_size_in_bytes < threshold * 2) {
278 // on v9 we can do double word stores to fill twice as much space.
279 assert(hdr_size_in_bytes % 8 == 0, "double word aligned");
280 assert(con_size_in_bytes % 8 == 0, "double word aligned");
281 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += 2 * HeapWordSize) stx(G0, obj, i);
282 #endif
283 } else if (con_size_in_bytes <= threshold) {
284 // use explicit NULL stores
285 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += HeapWordSize) st_ptr(G0, obj, i);
286 } else if (con_size_in_bytes > hdr_size_in_bytes) {
287 // use a loop
288 const Register base = t1;
289 const Register index = t2;
290 add(obj, hdr_size_in_bytes, base); // compute address of first element
291 // compute index = number of words to clear
292 set(con_size_in_bytes - hdr_size_in_bytes, index);
293 initialize_body(base, index);
294 }
295 }
296
297 if (CURRENT_ENV->dtrace_alloc_probes()) {
298 assert(obj == O0, "must be");
299 call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)),
300 relocInfo::runtime_call_type);
301 delayed()->nop();
302 }
303
304 verify_oop(obj);
305 }
306
307
308 void C1_MacroAssembler::allocate_array(
309 Register obj, // result: pointer to array after successful allocation
310 Register len, // array length
311 Register t1, // temp register
312 Register t2, // temp register
313 Register t3, // temp register
314 int hdr_size, // object header size in words
315 int elt_size, // element size in bytes
316 Register klass, // object klass
317 Label& slow_case // continuation point if fast allocation fails
318 ) {
319 assert_different_registers(obj, len, t1, t2, t3, klass);
320 assert(klass == G5, "must be G5");
321 assert(t1 == G1, "must be G1");
322
323 // determine alignment mask
324 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
325
326 // check for negative or excessive length
327 // note: the maximum length allowed is chosen so that arrays of any
328 // element size with this length are always smaller or equal
329 // to the largest integer (i.e., array size computation will
330 // not overflow)
331 set(max_array_allocation_length, t1);
332 cmp(len, t1);
333 br(Assembler::greaterUnsigned, false, Assembler::pn, slow_case);
334
335 // compute array size
336 // note: if 0 <= len <= max_length, len*elt_size + header + alignment is
337 // smaller or equal to the largest integer; also, since top is always
338 // aligned, we can do the alignment here instead of at the end address
339 // computation
340 const Register arr_size = t1;
341 switch (elt_size) {
342 case 1: delayed()->mov(len, arr_size); break;
343 case 2: delayed()->sll(len, 1, arr_size); break;
344 case 4: delayed()->sll(len, 2, arr_size); break;
345 case 8: delayed()->sll(len, 3, arr_size); break;
346 default: ShouldNotReachHere();
347 }
348 add(arr_size, hdr_size * wordSize + MinObjAlignmentInBytesMask, arr_size); // add space for header & alignment
349 and3(arr_size, ~MinObjAlignmentInBytesMask, arr_size); // align array size
350
351 // allocate space & initialize header
352 if (UseTLAB) {
353 tlab_allocate(obj, arr_size, 0, t2, slow_case);
354 } else {
355 eden_allocate(obj, arr_size, 0, t2, t3, slow_case);
356 }
357 initialize_header(obj, klass, len, t2, t3);
358
359 // initialize body
360 const Register base = t2;
361 const Register index = t3;
362 add(obj, hdr_size * wordSize, base); // compute address of first element
363 sub(arr_size, hdr_size * wordSize, index); // compute index = number of words to clear
364 initialize_body(base, index);
365
366 if (CURRENT_ENV->dtrace_alloc_probes()) {
367 assert(obj == O0, "must be");
368 call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)),
369 relocInfo::runtime_call_type);
370 delayed()->nop();
371 }
372
373 verify_oop(obj);
374 }
375
376
377 #ifndef PRODUCT
378
379 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
380 if (!VerifyOops) return;
381 verify_oop_addr(Address(SP, stack_offset + STACK_BIAS));
382 }
383
384 void C1_MacroAssembler::verify_not_null_oop(Register r) {
385 Label not_null;
386 br_notnull_short(r, Assembler::pt, not_null);
387 stop("non-null oop required");
388 bind(not_null);
389 if (!VerifyOops) return;
390 verify_oop(r);
391 }
392
393 void C1_MacroAssembler::invalidate_registers(bool iregisters, bool lregisters, bool oregisters,
394 Register preserve1, Register preserve2) {
395 if (iregisters) {
396 for (int i = 0; i < 6; i++) {
397 Register r = as_iRegister(i);
398 if (r != preserve1 && r != preserve2) set(0xdead, r);
399 }
400 }
401 if (oregisters) {
402 for (int i = 0; i < 6; i++) {
403 Register r = as_oRegister(i);
404 if (r != preserve1 && r != preserve2) set(0xdead, r);
405 }
406 }
407 if (lregisters) {
408 for (int i = 0; i < 8; i++) {
409 Register r = as_lRegister(i);
410 if (r != preserve1 && r != preserve2) set(0xdead, r);
411 }
412 }
413 }
414
415
416 #endif