1 /*
2 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2012, 2018 SAP SE. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "asm/macroAssembler.inline.hpp"
28 #include "c1/c1_MacroAssembler.hpp"
29 #include "c1/c1_Runtime1.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "gc/shared/collectedHeap.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "oops/arrayOop.hpp"
34 #include "oops/markWord.hpp"
35 #include "runtime/basicLock.hpp"
36 #include "runtime/biasedLocking.hpp"
37 #include "runtime/os.hpp"
38 #include "runtime/sharedRuntime.hpp"
39 #include "runtime/stubRoutines.hpp"
40 #include "utilities/align.hpp"
41
42
43 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
44 const Register temp_reg = R12_scratch2;
45 Label Lmiss;
46
47 verify_oop(receiver, FILE_AND_LINE);
48 MacroAssembler::null_check(receiver, oopDesc::klass_offset_in_bytes(), &Lmiss);
49 load_klass(temp_reg, receiver);
50
51 if (TrapBasedICMissChecks && TrapBasedNullChecks) {
52 trap_ic_miss_check(temp_reg, iCache);
53 } else {
54 Label Lok;
55 cmpd(CCR0, temp_reg, iCache);
56 beq(CCR0, Lok);
57 bind(Lmiss);
58 //load_const_optimized(temp_reg, SharedRuntime::get_ic_miss_stub(), R0);
59 calculate_address_from_global_toc(temp_reg, SharedRuntime::get_ic_miss_stub(), true, true, false);
60 mtctr(temp_reg);
61 bctr();
62 align(32, 12);
63 bind(Lok);
64 }
65 }
66
67
68 void C1_MacroAssembler::explicit_null_check(Register base) {
69 Unimplemented();
70 }
71
72
73 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) {
74 // Avoid stack bang as first instruction. It may get overwritten by patch_verified_entry.
75 const Register return_pc = R20;
76 mflr(return_pc);
77
78 // Make sure there is enough stack space for this method's activation.
79 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
80 generate_stack_overflow_check(bang_size_in_bytes);
81
82 std(return_pc, _abi(lr), R1_SP); // SP->lr = return_pc
83 push_frame(frame_size_in_bytes, R0); // SP -= frame_size_in_bytes
84 }
85
86
87 void C1_MacroAssembler::verified_entry() {
88 if (C1Breakpoint) illtrap();
89 // build frame
90 }
91
92
93 void C1_MacroAssembler::lock_object(Register Rmark, Register Roop, Register Rbox, Register Rscratch, Label& slow_case) {
94 assert_different_registers(Rmark, Roop, Rbox, Rscratch);
95
96 Label done, cas_failed, slow_int;
97
98 // The following move must be the first instruction of emitted since debug
99 // information may be generated for it.
100 // Load object header.
101 ld(Rmark, oopDesc::mark_offset_in_bytes(), Roop);
102
103 verify_oop(Roop, FILE_AND_LINE);
104
105 // Save object being locked into the BasicObjectLock...
106 std(Roop, BasicObjectLock::obj_offset_in_bytes(), Rbox);
107
108 if (UseBiasedLocking) {
109 biased_locking_enter(CCR0, Roop, Rmark, Rscratch, R0, done, &slow_int);
110 }
111
112 // ... and mark it unlocked.
113 ori(Rmark, Rmark, markWord::unlocked_value);
114
115 // Save unlocked object header into the displaced header location on the stack.
116 std(Rmark, BasicLock::displaced_header_offset_in_bytes(), Rbox);
117
118 // Compare object markWord with Rmark and if equal exchange Rscratch with object markWord.
119 assert(oopDesc::mark_offset_in_bytes() == 0, "cas must take a zero displacement");
120 cmpxchgd(/*flag=*/CCR0,
121 /*current_value=*/Rscratch,
122 /*compare_value=*/Rmark,
123 /*exchange_value=*/Rbox,
124 /*where=*/Roop/*+0==mark_offset_in_bytes*/,
125 MacroAssembler::MemBarRel | MacroAssembler::MemBarAcq,
126 MacroAssembler::cmpxchgx_hint_acquire_lock(),
127 noreg,
128 &cas_failed,
129 /*check without membar and ldarx first*/true);
130 // If compare/exchange succeeded we found an unlocked object and we now have locked it
131 // hence we are done.
132 b(done);
133
134 bind(slow_int);
135 b(slow_case); // far
136
137 bind(cas_failed);
138 // We did not find an unlocked object so see if this is a recursive case.
139 sub(Rscratch, Rscratch, R1_SP);
140 load_const_optimized(R0, (~(os::vm_page_size()-1) | markWord::lock_mask_in_place));
141 and_(R0/*==0?*/, Rscratch, R0);
142 std(R0/*==0, perhaps*/, BasicLock::displaced_header_offset_in_bytes(), Rbox);
143 bne(CCR0, slow_int);
144
145 bind(done);
146 }
147
148
149 void C1_MacroAssembler::unlock_object(Register Rmark, Register Roop, Register Rbox, Label& slow_case) {
150 assert_different_registers(Rmark, Roop, Rbox);
151
152 Label slow_int, done;
153
154 Address mark_addr(Roop, oopDesc::mark_offset_in_bytes());
155 assert(mark_addr.disp() == 0, "cas must take a zero displacement");
156
157 if (UseBiasedLocking) {
158 // Load the object out of the BasicObjectLock.
159 ld(Roop, BasicObjectLock::obj_offset_in_bytes(), Rbox);
160 verify_oop(Roop, FILE_AND_LINE);
161 biased_locking_exit(CCR0, Roop, R0, done);
162 }
163 // Test first it it is a fast recursive unlock.
164 ld(Rmark, BasicLock::displaced_header_offset_in_bytes(), Rbox);
165 cmpdi(CCR0, Rmark, 0);
166 beq(CCR0, done);
167 if (!UseBiasedLocking) {
168 // Load object.
169 ld(Roop, BasicObjectLock::obj_offset_in_bytes(), Rbox);
170 verify_oop(Roop, FILE_AND_LINE);
171 }
172
173 // Check if it is still a light weight lock, this is is true if we see
174 // the stack address of the basicLock in the markWord of the object.
175 cmpxchgd(/*flag=*/CCR0,
176 /*current_value=*/R0,
177 /*compare_value=*/Rbox,
178 /*exchange_value=*/Rmark,
179 /*where=*/Roop,
180 MacroAssembler::MemBarRel,
181 MacroAssembler::cmpxchgx_hint_release_lock(),
182 noreg,
183 &slow_int);
184 b(done);
185 bind(slow_int);
186 b(slow_case); // far
187
188 // Done
189 bind(done);
190 }
191
192
193 void C1_MacroAssembler::try_allocate(
194 Register obj, // result: pointer to object after successful allocation
195 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise
196 int con_size_in_bytes, // object size in bytes if known at compile time
197 Register t1, // temp register, must be global register for incr_allocated_bytes
198 Register t2, // temp register
199 Label& slow_case // continuation point if fast allocation fails
200 ) {
201 if (UseTLAB) {
202 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
203 } else {
204 eden_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
205 RegisterOrConstant size_in_bytes = var_size_in_bytes->is_valid()
206 ? RegisterOrConstant(var_size_in_bytes)
207 : RegisterOrConstant(con_size_in_bytes);
208 incr_allocated_bytes(size_in_bytes, t1, t2);
209 }
210 }
211
212
213 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
214 assert_different_registers(obj, klass, len, t1, t2);
215 if (UseBiasedLocking && !len->is_valid()) {
216 ld(t1, in_bytes(Klass::prototype_header_offset()), klass);
217 } else {
218 load_const_optimized(t1, (intx)markWord::prototype().value());
219 }
220 std(t1, oopDesc::mark_offset_in_bytes(), obj);
221 store_klass(obj, klass);
222 if (len->is_valid()) {
223 stw(len, arrayOopDesc::length_offset_in_bytes(), obj);
224 } else if (UseCompressedClassPointers) {
225 // Otherwise length is in the class gap.
226 store_klass_gap(obj);
227 }
228 }
229
230
231 void C1_MacroAssembler::initialize_body(Register base, Register index) {
232 assert_different_registers(base, index);
233 srdi(index, index, LogBytesPerWord);
234 clear_memory_doubleword(base, index);
235 }
236
237 void C1_MacroAssembler::initialize_body(Register obj, Register tmp1, Register tmp2,
238 int obj_size_in_bytes, int hdr_size_in_bytes) {
239 const int index = (obj_size_in_bytes - hdr_size_in_bytes) / HeapWordSize;
240
241 // 2x unrolled loop is shorter with more than 9 HeapWords.
242 if (index <= 9) {
243 clear_memory_unrolled(obj, index, R0, hdr_size_in_bytes);
244 } else {
245 const Register base_ptr = tmp1,
246 cnt_dwords = tmp2;
247
248 addi(base_ptr, obj, hdr_size_in_bytes); // Compute address of first element.
249 clear_memory_doubleword(base_ptr, cnt_dwords, R0, index);
250 }
251 }
252
253 void C1_MacroAssembler::allocate_object(
254 Register obj, // result: pointer to object after successful allocation
255 Register t1, // temp register
256 Register t2, // temp register
257 Register t3, // temp register
258 int hdr_size, // object header size in words
259 int obj_size, // object size in words
260 Register klass, // object klass
261 Label& slow_case // continuation point if fast allocation fails
262 ) {
263 assert_different_registers(obj, t1, t2, t3, klass);
264
265 // allocate space & initialize header
266 if (!is_simm16(obj_size * wordSize)) {
267 // Would need to use extra register to load
268 // object size => go the slow case for now.
269 b(slow_case);
270 return;
271 }
272 try_allocate(obj, noreg, obj_size * wordSize, t2, t3, slow_case);
273
274 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2);
275 }
276
277 void C1_MacroAssembler::initialize_object(
278 Register obj, // result: pointer to object after successful allocation
279 Register klass, // object klass
280 Register var_size_in_bytes, // object size in bytes if unknown at compile time; invalid otherwise
281 int con_size_in_bytes, // object size in bytes if known at compile time
282 Register t1, // temp register
283 Register t2 // temp register
284 ) {
285 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
286
287 initialize_header(obj, klass, noreg, t1, t2);
288
289 #ifdef ASSERT
290 {
291 lwz(t1, in_bytes(Klass::layout_helper_offset()), klass);
292 if (var_size_in_bytes != noreg) {
293 cmpw(CCR0, t1, var_size_in_bytes);
294 } else {
295 cmpwi(CCR0, t1, con_size_in_bytes);
296 }
297 asm_assert_eq("bad size in initialize_object", 0x753);
298 }
299 #endif
300
301 // Initialize body.
302 if (var_size_in_bytes != noreg) {
303 // Use a loop.
304 addi(t1, obj, hdr_size_in_bytes); // Compute address of first element.
305 addi(t2, var_size_in_bytes, -hdr_size_in_bytes); // Compute size of body.
306 initialize_body(t1, t2);
307 } else if (con_size_in_bytes > hdr_size_in_bytes) {
308 // Use a loop.
309 initialize_body(obj, t1, t2, con_size_in_bytes, hdr_size_in_bytes);
310 }
311
312 if (CURRENT_ENV->dtrace_alloc_probes()) {
313 Unimplemented();
314 // assert(obj == O0, "must be");
315 // call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)),
316 // relocInfo::runtime_call_type);
317 }
318
319 verify_oop(obj, FILE_AND_LINE);
320 }
321
322
323 void C1_MacroAssembler::allocate_array(
324 Register obj, // result: pointer to array after successful allocation
325 Register len, // array length
326 Register t1, // temp register
327 Register t2, // temp register
328 Register t3, // temp register
329 int hdr_size, // object header size in words
330 int elt_size, // element size in bytes
331 Register klass, // object klass
332 Label& slow_case // continuation point if fast allocation fails
333 ) {
334 assert_different_registers(obj, len, t1, t2, t3, klass);
335
336 // Determine alignment mask.
337 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
338 int log2_elt_size = exact_log2(elt_size);
339
340 // Check for negative or excessive length.
341 size_t max_length = max_array_allocation_length >> log2_elt_size;
342 if (UseTLAB) {
343 size_t max_tlab = align_up(ThreadLocalAllocBuffer::max_size() >> log2_elt_size, 64*K);
344 if (max_tlab < max_length) { max_length = max_tlab; }
345 }
346 load_const_optimized(t1, max_length);
347 cmpld(CCR0, len, t1);
348 bc_far_optimized(Assembler::bcondCRbiIs1, bi0(CCR0, Assembler::greater), slow_case);
349
350 // compute array size
351 // note: If 0 <= len <= max_length, len*elt_size + header + alignment is
352 // smaller or equal to the largest integer; also, since top is always
353 // aligned, we can do the alignment here instead of at the end address
354 // computation.
355 const Register arr_size = t1;
356 Register arr_len_in_bytes = len;
357 if (elt_size != 1) {
358 sldi(t1, len, log2_elt_size);
359 arr_len_in_bytes = t1;
360 }
361 addi(arr_size, arr_len_in_bytes, hdr_size * wordSize + MinObjAlignmentInBytesMask); // Add space for header & alignment.
362 clrrdi(arr_size, arr_size, LogMinObjAlignmentInBytes); // Align array size.
363
364 // Allocate space & initialize header.
365 if (UseTLAB) {
366 tlab_allocate(obj, arr_size, 0, t2, slow_case);
367 } else {
368 eden_allocate(obj, arr_size, 0, t2, t3, slow_case);
369 }
370 initialize_header(obj, klass, len, t2, t3);
371
372 // Initialize body.
373 const Register base = t2;
374 const Register index = t3;
375 addi(base, obj, hdr_size * wordSize); // compute address of first element
376 addi(index, arr_size, -(hdr_size * wordSize)); // compute index = number of bytes to clear
377 initialize_body(base, index);
378
379 if (CURRENT_ENV->dtrace_alloc_probes()) {
380 Unimplemented();
381 //assert(obj == O0, "must be");
382 //call(CAST_FROM_FN_PTR(address, Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)),
383 // relocInfo::runtime_call_type);
384 }
385
386 verify_oop(obj, FILE_AND_LINE);
387 }
388
389
390 #ifndef PRODUCT
391
392 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
393 verify_oop_addr((RegisterOrConstant)(stack_offset + STACK_BIAS), R1_SP, "broken oop in stack slot");
394 }
395
396 void C1_MacroAssembler::verify_not_null_oop(Register r) {
397 Label not_null;
398 cmpdi(CCR0, r, 0);
399 bne(CCR0, not_null);
400 stop("non-null oop required");
401 bind(not_null);
402 verify_oop(r, FILE_AND_LINE);
403 }
404
405 #endif // PRODUCT
406
407 void C1_MacroAssembler::null_check(Register r, Label* Lnull) {
408 if (TrapBasedNullChecks) { // SIGTRAP based
409 trap_null_check(r);
410 } else { // explicit
411 //const address exception_entry = Runtime1::entry_for(Runtime1::throw_null_pointer_exception_id);
412 assert(Lnull != NULL, "must have Label for explicit check");
413 cmpdi(CCR0, r, 0);
414 bc_far_optimized(Assembler::bcondCRbiIs1, bi0(CCR0, Assembler::equal), *Lnull);
415 }
416 }
417
418 address C1_MacroAssembler::call_c_with_frame_resize(address dest, int frame_resize) {
419 if (frame_resize) { resize_frame(-frame_resize, R0); }
420 #if defined(ABI_ELFv2)
421 address return_pc = call_c(dest, relocInfo::runtime_call_type);
422 #else
423 address return_pc = call_c(CAST_FROM_FN_PTR(FunctionDescriptor*, dest), relocInfo::runtime_call_type);
424 #endif
425 if (frame_resize) { resize_frame(frame_resize, R0); }
426 return return_pc;
427 }