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