1 /*
2 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2016 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
41 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
42 Label ic_miss, ic_hit;
43 verify_oop(receiver, FILE_AND_LINE);
44 int klass_offset = oopDesc::klass_offset_in_bytes();
45
46 if (!ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(klass_offset)) {
47 if (VM_Version::has_CompareBranch()) {
48 z_cgij(receiver, 0, Assembler::bcondEqual, ic_miss);
49 } else {
50 z_ltgr(receiver, receiver);
51 z_bre(ic_miss);
52 }
53 }
54
55 compare_klass_ptr(iCache, klass_offset, receiver, false);
56 z_bre(ic_hit);
57
58 // If icache check fails, then jump to runtime routine.
59 // Note: RECEIVER must still contain the receiver!
60 load_const_optimized(Z_R1_scratch, AddressLiteral(SharedRuntime::get_ic_miss_stub()));
61 z_br(Z_R1_scratch);
62 align(CodeEntryAlignment);
63 bind(ic_hit);
64 }
65
66 void C1_MacroAssembler::explicit_null_check(Register base) {
67 ShouldNotCallThis(); // unused
68 }
69
70 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) {
71 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
72 generate_stack_overflow_check(bang_size_in_bytes);
73 save_return_pc();
74 push_frame(frame_size_in_bytes);
75 }
76
77 void C1_MacroAssembler::verified_entry() {
78 if (C1Breakpoint) z_illtrap(0xC1);
79 }
80
81 void C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
82 const int hdr_offset = oopDesc::mark_offset_in_bytes();
83 assert_different_registers(hdr, obj, disp_hdr);
84 NearLabel done;
85
86 verify_oop(obj, FILE_AND_LINE);
87
88 // Load object header.
89 z_lg(hdr, Address(obj, hdr_offset));
90
91 // Save object being locked into the BasicObjectLock...
92 z_stg(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
93
94 if (UseBiasedLocking) {
95 biased_locking_enter(obj, hdr, Z_R1_scratch, Z_R0_scratch, done, &slow_case);
96 }
97
98 // and mark it as unlocked.
99 z_oill(hdr, markWord::unlocked_value);
100 // Save unlocked object header into the displaced header location on the stack.
101 z_stg(hdr, Address(disp_hdr, (intptr_t)0));
102 // Test if object header is still the same (i.e. unlocked), and if so, store the
103 // displaced header address in the object header. If it is not the same, get the
104 // object header instead.
105 z_csg(hdr, disp_hdr, hdr_offset, obj);
106 // If the object header was the same, we're done.
107 if (PrintBiasedLockingStatistics) {
108 Unimplemented();
109 #if 0
110 cond_inc32(Assembler::equal,
111 ExternalAddress((address)BiasedLocking::fast_path_entry_count_addr()));
112 #endif
113 }
114 branch_optimized(Assembler::bcondEqual, done);
115 // If the object header was not the same, it is now in the hdr register.
116 // => Test if it is a stack pointer into the same stack (recursive locking), i.e.:
117 //
118 // 1) (hdr & markWord::lock_mask_in_place) == 0
119 // 2) rsp <= hdr
120 // 3) hdr <= rsp + page_size
121 //
122 // These 3 tests can be done by evaluating the following expression:
123 //
124 // (hdr - Z_SP) & (~(page_size-1) | markWord::lock_mask_in_place)
125 //
126 // assuming both the stack pointer and page_size have their least
127 // significant 2 bits cleared and page_size is a power of 2
128 z_sgr(hdr, Z_SP);
129
130 load_const_optimized(Z_R0_scratch, (~(os::vm_page_size()-1) | markWord::lock_mask_in_place));
131 z_ngr(hdr, Z_R0_scratch); // AND sets CC (result eq/ne 0).
132 // For recursive locking, the result is zero. => Save it in the displaced header
133 // location (NULL in the displaced hdr location indicates recursive locking).
134 z_stg(hdr, Address(disp_hdr, (intptr_t)0));
135 // Otherwise we don't care about the result and handle locking via runtime call.
136 branch_optimized(Assembler::bcondNotZero, slow_case);
137 // done
138 bind(done);
139 }
140
141 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
142 const int aligned_mask = BytesPerWord -1;
143 const int hdr_offset = oopDesc::mark_offset_in_bytes();
144 assert_different_registers(hdr, obj, disp_hdr);
145 NearLabel done;
146
147 if (UseBiasedLocking) {
148 // Load object.
149 z_lg(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
150 biased_locking_exit(obj, hdr, done);
151 }
152
153 // Load displaced header.
154 z_ltg(hdr, Address(disp_hdr, (intptr_t)0));
155 // If the loaded hdr is NULL we had recursive locking, and we are done.
156 z_bre(done);
157 if (!UseBiasedLocking) {
158 // Load object.
159 z_lg(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
160 }
161 verify_oop(obj, FILE_AND_LINE);
162 // Test if object header is pointing to the displaced header, and if so, restore
163 // the displaced header in the object. If the object header is not pointing to
164 // the displaced header, get the object header instead.
165 z_csg(disp_hdr, hdr, hdr_offset, obj);
166 // If the object header was not pointing to the displaced header,
167 // we do unlocking via runtime call.
168 branch_optimized(Assembler::bcondNotEqual, slow_case);
169 // done
170 bind(done);
171 }
172
173 void C1_MacroAssembler::try_allocate(
174 Register obj, // result: Pointer to object after successful allocation.
175 Register var_size_in_bytes, // Object size in bytes if unknown at compile time; invalid otherwise.
176 int con_size_in_bytes, // Object size in bytes if known at compile time.
177 Register t1, // Temp register: Must be global register for incr_allocated_bytes.
178 Label& slow_case // Continuation point if fast allocation fails.
179 ) {
180 if (UseTLAB) {
181 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
182 } else {
183 // Allocation in shared Eden not implemented, because sapjvm allocation trace does not allow it.
184 z_brul(slow_case);
185 }
186 }
187
188 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register Rzero, Register t1) {
189 assert_different_registers(obj, klass, len, t1, Rzero);
190 if (UseBiasedLocking && !len->is_valid()) {
191 assert_different_registers(obj, klass, len, t1);
192 z_lg(t1, Address(klass, Klass::prototype_header_offset()));
193 } else {
194 // This assumes that all prototype bits fit in an int32_t.
195 load_const_optimized(t1, (intx)markWord::prototype().value());
196 }
197 z_stg(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
198
199 if (len->is_valid()) {
200 // Length will be in the klass gap, if one exists.
201 z_st(len, Address(obj, arrayOopDesc::length_offset_in_bytes()));
202 } else if (UseCompressedClassPointers) {
203 store_klass_gap(Rzero, obj); // Zero klass gap for compressed oops.
204 }
205 store_klass(klass, obj, t1);
206 }
207
208 void C1_MacroAssembler::initialize_body(Register objectFields, Register len_in_bytes, Register Rzero) {
209 Label done;
210 assert_different_registers(objectFields, len_in_bytes, Rzero);
211
212 // Initialize object fields.
213 // See documentation for MVCLE instruction!!!
214 assert(objectFields->encoding()%2==0, "objectFields must be an even register");
215 assert(len_in_bytes->encoding() == (objectFields->encoding()+1), "objectFields and len_in_bytes must be a register pair");
216 assert(Rzero->encoding()%2==1, "Rzero must be an odd register");
217
218 // Use Rzero as src length, then mvcle will copy nothing
219 // and fill the object with the padding value 0.
220 move_long_ext(objectFields, as_Register(Rzero->encoding()-1), 0);
221 bind(done);
222 }
223
224 void C1_MacroAssembler::allocate_object(
225 Register obj, // Result: pointer to object after successful allocation.
226 Register t1, // temp register
227 Register t2, // temp register: Must be a global register for try_allocate.
228 int hdr_size, // object header size in words
229 int obj_size, // object size in words
230 Register klass, // object klass
231 Label& slow_case // Continuation point if fast allocation fails.
232 ) {
233 assert_different_registers(obj, t1, t2, klass);
234
235 // Allocate space and initialize header.
236 try_allocate(obj, noreg, obj_size * wordSize, t1, slow_case);
237
238 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2);
239 }
240
241 void C1_MacroAssembler::initialize_object(
242 Register obj, // result: Pointer to object after successful allocation.
243 Register klass, // object klass
244 Register var_size_in_bytes, // Object size in bytes if unknown at compile time; invalid otherwise.
245 int con_size_in_bytes, // Object size in bytes if known at compile time.
246 Register t1, // temp register
247 Register t2 // temp register
248 ) {
249 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
250 "con_size_in_bytes is not multiple of alignment");
251 assert(var_size_in_bytes == noreg, "not implemented");
252 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
253
254 const Register Rzero = t2;
255
256 z_xgr(Rzero, Rzero);
257 initialize_header(obj, klass, noreg, Rzero, t1);
258
259 // Clear rest of allocated space.
260 const int threshold = 4 * BytesPerWord;
261 if (con_size_in_bytes <= threshold) {
262 // Use explicit null stores.
263 // code size = 6*n bytes (n = number of fields to clear)
264 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
265 z_stg(Rzero, Address(obj, i));
266 } else {
267 // Code size generated by initialize_body() is 16.
268 Register object_fields = Z_R0_scratch;
269 Register len_in_bytes = Z_R1_scratch;
270 z_la(object_fields, hdr_size_in_bytes, obj);
271 load_const_optimized(len_in_bytes, con_size_in_bytes - hdr_size_in_bytes);
272 initialize_body(object_fields, len_in_bytes, Rzero);
273 }
274
275 // Dtrace support is unimplemented.
276 // if (CURRENT_ENV->dtrace_alloc_probes()) {
277 // assert(obj == rax, "must be");
278 // call(RuntimeAddress(Runtime1::entry_for (Runtime1::dtrace_object_alloc_id)));
279 // }
280
281 verify_oop(obj, FILE_AND_LINE);
282 }
283
284 void C1_MacroAssembler::allocate_array(
285 Register obj, // result: Pointer to array after successful allocation.
286 Register len, // array length
287 Register t1, // temp register
288 Register t2, // temp register
289 int hdr_size, // object header size in words
290 int elt_size, // element size in bytes
291 Register klass, // object klass
292 Label& slow_case // Continuation point if fast allocation fails.
293 ) {
294 assert_different_registers(obj, len, t1, t2, klass);
295
296 // Determine alignment mask.
297 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
298
299 // Check for negative or excessive length.
300 compareU64_and_branch(len, (int32_t)max_array_allocation_length, bcondHigh, slow_case);
301
302 // Compute array size.
303 // Note: If 0 <= len <= max_length, len*elt_size + header + alignment is
304 // smaller or equal to the largest integer. Also, since top is always
305 // aligned, we can do the alignment here instead of at the end address
306 // computation.
307 const Register arr_size = t2;
308 switch (elt_size) {
309 case 1: lgr_if_needed(arr_size, len); break;
310 case 2: z_sllg(arr_size, len, 1); break;
311 case 4: z_sllg(arr_size, len, 2); break;
312 case 8: z_sllg(arr_size, len, 3); break;
313 default: ShouldNotReachHere();
314 }
315 add2reg(arr_size, hdr_size * wordSize + MinObjAlignmentInBytesMask); // Add space for header & alignment.
316 z_nill(arr_size, (~MinObjAlignmentInBytesMask) & 0xffff); // Align array size.
317
318 try_allocate(obj, arr_size, 0, t1, slow_case);
319
320 initialize_header(obj, klass, len, noreg, t1);
321
322 // Clear rest of allocated space.
323 Label done;
324 Register object_fields = t1;
325 Register Rzero = Z_R1_scratch;
326 z_aghi(arr_size, -(hdr_size * BytesPerWord));
327 z_bre(done); // Jump if size of fields is zero.
328 z_la(object_fields, hdr_size * BytesPerWord, obj);
329 z_xgr(Rzero, Rzero);
330 initialize_body(object_fields, arr_size, Rzero);
331 bind(done);
332
333 // Dtrace support is unimplemented.
334 // if (CURRENT_ENV->dtrace_alloc_probes()) {
335 // assert(obj == rax, "must be");
336 // call(RuntimeAddress(Runtime1::entry_for (Runtime1::dtrace_object_alloc_id)));
337 // }
338
339 verify_oop(obj, FILE_AND_LINE);
340 }
341
342
343 #ifndef PRODUCT
344
345 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
346 if (!VerifyOops) return;
347 verify_oop_addr(Address(Z_SP, stack_offset), FILE_AND_LINE);
348 }
349
350 void C1_MacroAssembler::verify_not_null_oop(Register r) {
351 if (!VerifyOops) return;
352 NearLabel not_null;
353 compareU64_and_branch(r, (intptr_t)0, bcondNotEqual, not_null);
354 stop("non-null oop required");
355 bind(not_null);
356 verify_oop(r, FILE_AND_LINE);
357 }
358
359 void C1_MacroAssembler::invalidate_registers(Register preserve1,
360 Register preserve2,
361 Register preserve3) {
362 Register dead_value = noreg;
363 for (int i = 0; i < FrameMap::nof_cpu_regs; i++) {
364 Register r = as_Register(i);
365 if (r != preserve1 && r != preserve2 && r != preserve3 && r != Z_SP && r != Z_thread) {
366 if (dead_value == noreg) {
367 load_const_optimized(r, 0xc1dead);
368 dead_value = r;
369 } else {
370 z_lgr(r, dead_value);
371 }
372 }
373 }
374 }
375
376 #endif // !PRODUCT