1 /*
2 * Copyright (c) 2016, 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 "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
40 void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
41 Label ic_miss, ic_hit;
42 verify_oop(receiver);
43 int klass_offset = oopDesc::klass_offset_in_bytes();
44
45 if (!ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(klass_offset)) {
46 if (VM_Version::has_CompareBranch()) {
47 z_cgij(receiver, 0, Assembler::bcondEqual, ic_miss);
48 } else {
49 z_ltgr(receiver, receiver);
50 z_bre(ic_miss);
51 }
52 }
53
54 compare_klass_ptr(iCache, klass_offset, receiver, false);
55 z_bre(ic_hit);
56
57 // If icache check fails, then jump to runtime routine.
58 // Note: RECEIVER must still contain the receiver!
59 load_const_optimized(Z_R1_scratch, AddressLiteral(SharedRuntime::get_ic_miss_stub()));
60 z_br(Z_R1_scratch);
61 align(CodeEntryAlignment);
62 bind(ic_hit);
63 }
64
65 void C1_MacroAssembler::explicit_null_check(Register base) {
66 ShouldNotCallThis(); // unused
67 }
68
69 void C1_MacroAssembler::build_frame(int frame_size_in_bytes, int bang_size_in_bytes) {
70 assert(bang_size_in_bytes >= frame_size_in_bytes, "stack bang size incorrect");
71 generate_stack_overflow_check(bang_size_in_bytes);
72 save_return_pc();
73 push_frame(frame_size_in_bytes);
74 }
75
76 void C1_MacroAssembler::unverified_entry(Register receiver, Register ic_klass) {
77 ShouldNotCallThis(); // unused
78 }
79
80 void C1_MacroAssembler::verified_entry() {
81 if (C1Breakpoint) z_illtrap(0xC1);
82 }
83
84 void C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
85 const int hdr_offset = oopDesc::mark_offset_in_bytes();
86 assert_different_registers(hdr, obj, disp_hdr);
87 NearLabel done;
88
89 verify_oop(obj);
90
91 // Load object header.
92 z_lg(hdr, Address(obj, hdr_offset));
93
94 // Save object being locked into the BasicObjectLock...
95 z_stg(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
96
97 if (UseBiasedLocking) {
98 biased_locking_enter(obj, hdr, Z_R1_scratch, Z_R0_scratch, done, &slow_case);
99 }
100
101 // and mark it as unlocked.
102 z_oill(hdr, markOopDesc::unlocked_value);
103 // Save unlocked object header into the displaced header location on the stack.
104 z_stg(hdr, Address(disp_hdr, (intptr_t)0));
105 // Test if object header is still the same (i.e. unlocked), and if so, store the
106 // displaced header address in the object header. If it is not the same, get the
107 // object header instead.
108 z_csg(hdr, disp_hdr, hdr_offset, obj);
109 // If the object header was the same, we're done.
110 if (PrintBiasedLockingStatistics) {
111 Unimplemented();
112 #if 0
113 cond_inc32(Assembler::equal,
114 ExternalAddress((address)BiasedLocking::fast_path_entry_count_addr()));
115 #endif
116 }
117 branch_optimized(Assembler::bcondEqual, done);
118 // If the object header was not the same, it is now in the hdr register.
119 // => Test if it is a stack pointer into the same stack (recursive locking), i.e.:
120 //
121 // 1) (hdr & markOopDesc::lock_mask_in_place) == 0
122 // 2) rsp <= hdr
123 // 3) hdr <= rsp + page_size
124 //
125 // These 3 tests can be done by evaluating the following expression:
126 //
127 // (hdr - Z_SP) & (~(page_size-1) | markOopDesc::lock_mask_in_place)
128 //
129 // assuming both the stack pointer and page_size have their least
130 // significant 2 bits cleared and page_size is a power of 2
131 z_sgr(hdr, Z_SP);
132
133 load_const_optimized(Z_R0_scratch, (~(os::vm_page_size()-1) | markOopDesc::lock_mask_in_place));
134 z_ngr(hdr, Z_R0_scratch); // AND sets CC (result eq/ne 0).
135 // For recursive locking, the result is zero. => Save it in the displaced header
136 // location (NULL in the displaced hdr location indicates recursive locking).
137 z_stg(hdr, Address(disp_hdr, (intptr_t)0));
138 // Otherwise we don't care about the result and handle locking via runtime call.
139 branch_optimized(Assembler::bcondNotZero, slow_case);
140 // done
141 bind(done);
142 }
143
144 void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_hdr, Label& slow_case) {
145 const int aligned_mask = BytesPerWord -1;
146 const int hdr_offset = oopDesc::mark_offset_in_bytes();
147 assert_different_registers(hdr, obj, disp_hdr);
148 NearLabel done;
149
150 if (UseBiasedLocking) {
151 // Load object.
152 z_lg(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
153 biased_locking_exit(obj, hdr, done);
154 }
155
156 // Load displaced header.
157 z_ltg(hdr, Address(disp_hdr, (intptr_t)0));
158 // If the loaded hdr is NULL we had recursive locking, and we are done.
159 z_bre(done);
160 if (!UseBiasedLocking) {
161 // Load object.
162 z_lg(obj, Address(disp_hdr, BasicObjectLock::obj_offset_in_bytes()));
163 }
164 verify_oop(obj);
165 // Test if object header is pointing to the displaced header, and if so, restore
166 // the displaced header in the object. If the object header is not pointing to
167 // the displaced header, get the object header instead.
168 z_csg(disp_hdr, hdr, hdr_offset, obj);
169 // If the object header was not pointing to the displaced header,
170 // we do unlocking via runtime call.
171 branch_optimized(Assembler::bcondNotEqual, slow_case);
172 // done
173 bind(done);
174 }
175
176 void C1_MacroAssembler::try_allocate(
177 Register obj, // result: Pointer to object after successful allocation.
178 Register var_size_in_bytes, // Object size in bytes if unknown at compile time; invalid otherwise.
179 int con_size_in_bytes, // Object size in bytes if known at compile time.
180 Register t1, // Temp register: Must be global register for incr_allocated_bytes.
181 Label& slow_case // Continuation point if fast allocation fails.
182 ) {
183 if (UseTLAB) {
184 tlab_allocate(obj, var_size_in_bytes, con_size_in_bytes, t1, slow_case);
185 } else {
186 // Allocation in shared Eden not implemented, because sapjvm allocation trace does not allow it.
187 z_brul(slow_case);
188 }
189 }
190
191 void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register Rzero, Register t1) {
192 assert_different_registers(obj, klass, len, t1, Rzero);
193 if (UseBiasedLocking && !len->is_valid()) {
194 assert_different_registers(obj, klass, len, t1);
195 z_lg(t1, Address(klass, Klass::prototype_header_offset()));
196 } else {
197 // This assumes that all prototype bits fit in an int32_t.
198 load_const_optimized(t1, (intx)markOopDesc::prototype());
199 }
200 z_stg(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
201
202 if (len->is_valid()) {
203 // Length will be in the klass gap, if one exists.
204 z_st(len, Address(obj, arrayOopDesc::length_offset_in_bytes()));
205 } else if (UseCompressedClassPointers) {
206 store_klass_gap(Rzero, obj); // Zero klass gap for compressed oops.
207 }
208 store_klass(klass, obj, t1);
209 }
210
211 void C1_MacroAssembler::initialize_body(Register objectFields, Register len_in_bytes, Register Rzero) {
212 Label done;
213 assert_different_registers(objectFields, len_in_bytes, Rzero);
214
215 // Initialize object fields.
216 // See documentation for MVCLE instruction!!!
217 assert(objectFields->encoding()%2==0, "objectFields must be an even register");
218 assert(len_in_bytes->encoding() == (objectFields->encoding()+1), "objectFields and len_in_bytes must be a register pair");
219 assert(Rzero->encoding()%2==1, "Rzero must be an odd register");
220
221 // Use Rzero as src length, then mvcle will copy nothing
222 // and fill the object with the padding value 0.
223 move_long_ext(objectFields, as_Register(Rzero->encoding()-1), 0);
224 bind(done);
225 }
226
227 void C1_MacroAssembler::allocate_object(
228 Register obj, // Result: pointer to object after successful allocation.
229 Register t1, // temp register
230 Register t2, // temp register: Must be a global register for try_allocate.
231 int hdr_size, // object header size in words
232 int obj_size, // object size in words
233 Register klass, // object klass
234 Label& slow_case // Continuation point if fast allocation fails.
235 ) {
236 assert_different_registers(obj, t1, t2, klass);
237
238 // Allocate space and initialize header.
239 try_allocate(obj, noreg, obj_size * wordSize, t1, slow_case);
240
241 initialize_object(obj, klass, noreg, obj_size * HeapWordSize, t1, t2);
242 }
243
244 void C1_MacroAssembler::initialize_object(
245 Register obj, // result: Pointer to object after successful allocation.
246 Register klass, // object klass
247 Register var_size_in_bytes, // Object size in bytes if unknown at compile time; invalid otherwise.
248 int con_size_in_bytes, // Object size in bytes if known at compile time.
249 Register t1, // temp register
250 Register t2 // temp register
251 ) {
252 assert((con_size_in_bytes & MinObjAlignmentInBytesMask) == 0,
253 "con_size_in_bytes is not multiple of alignment");
254 assert(var_size_in_bytes == noreg, "not implemented");
255 const int hdr_size_in_bytes = instanceOopDesc::header_size() * HeapWordSize;
256
257 const Register Rzero = t2;
258
259 z_xgr(Rzero, Rzero);
260 initialize_header(obj, klass, noreg, Rzero, t1);
261
262 // Clear rest of allocated space.
263 const int threshold = 4 * BytesPerWord;
264 if (con_size_in_bytes <= threshold) {
265 // Use explicit null stores.
266 // code size = 6*n bytes (n = number of fields to clear)
267 for (int i = hdr_size_in_bytes; i < con_size_in_bytes; i += BytesPerWord)
268 z_stg(Rzero, Address(obj, i));
269 } else {
270 // Code size generated by initialize_body() is 16.
271 Register object_fields = Z_R0_scratch;
272 Register len_in_bytes = Z_R1_scratch;
273 z_la(object_fields, hdr_size_in_bytes, obj);
274 load_const_optimized(len_in_bytes, con_size_in_bytes - hdr_size_in_bytes);
275 initialize_body(object_fields, len_in_bytes, Rzero);
276 }
277
278 // Dtrace support is unimplemented.
279 // if (CURRENT_ENV->dtrace_alloc_probes()) {
280 // assert(obj == rax, "must be");
281 // call(RuntimeAddress(Runtime1::entry_for (Runtime1::dtrace_object_alloc_id)));
282 // }
283
284 verify_oop(obj);
285 }
286
287 void C1_MacroAssembler::allocate_array(
288 Register obj, // result: Pointer to array after successful allocation.
289 Register len, // array length
290 Register t1, // temp register
291 Register t2, // temp register
292 int hdr_size, // object header size in words
293 int elt_size, // element size in bytes
294 Register klass, // object klass
295 Label& slow_case // Continuation point if fast allocation fails.
296 ) {
297 assert_different_registers(obj, len, t1, t2, klass);
298
299 // Determine alignment mask.
300 assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
301
302 // Check for negative or excessive length.
303 compareU64_and_branch(len, (int32_t)max_array_allocation_length, bcondHigh, slow_case);
304
305 // Compute array size.
306 // Note: If 0 <= len <= max_length, len*elt_size + header + alignment is
307 // smaller or equal to the largest integer. Also, since top is always
308 // aligned, we can do the alignment here instead of at the end address
309 // computation.
310 const Register arr_size = t2;
311 switch (elt_size) {
312 case 1: lgr_if_needed(arr_size, len); break;
313 case 2: z_sllg(arr_size, len, 1); break;
314 case 4: z_sllg(arr_size, len, 2); break;
315 case 8: z_sllg(arr_size, len, 3); break;
316 default: ShouldNotReachHere();
317 }
318 add2reg(arr_size, hdr_size * wordSize + MinObjAlignmentInBytesMask); // Add space for header & alignment.
319 z_nill(arr_size, (~MinObjAlignmentInBytesMask) & 0xffff); // Align array size.
320
321 try_allocate(obj, arr_size, 0, t1, slow_case);
322
323 initialize_header(obj, klass, len, noreg, t1);
324
325 // Clear rest of allocated space.
326 Label done;
327 Register object_fields = t1;
328 Register Rzero = Z_R1_scratch;
329 z_aghi(arr_size, -(hdr_size * BytesPerWord));
330 z_bre(done); // Jump if size of fields is zero.
331 z_la(object_fields, hdr_size * BytesPerWord, obj);
332 z_xgr(Rzero, Rzero);
333 initialize_body(object_fields, arr_size, Rzero);
334 bind(done);
335
336 // Dtrace support is unimplemented.
337 // if (CURRENT_ENV->dtrace_alloc_probes()) {
338 // assert(obj == rax, "must be");
339 // call(RuntimeAddress(Runtime1::entry_for (Runtime1::dtrace_object_alloc_id)));
340 // }
341
342 verify_oop(obj);
343 }
344
345
346 #ifndef PRODUCT
347
348 void C1_MacroAssembler::verify_stack_oop(int stack_offset) {
349 Unimplemented();
350 // if (!VerifyOops) return;
351 // verify_oop_addr(Address(SP, stack_offset + STACK_BIAS));
352 }
353
354 void C1_MacroAssembler::verify_not_null_oop(Register r) {
355 if (!VerifyOops) return;
356 NearLabel not_null;
357 compareU64_and_branch(r, (intptr_t)0, bcondNotEqual, not_null);
358 stop("non-null oop required");
359 bind(not_null);
360 verify_oop(r);
361 }
362
363 void C1_MacroAssembler::invalidate_registers(Register preserve1,
364 Register preserve2,
365 Register preserve3) {
366 Register dead_value = noreg;
367 for (int i = 0; i < FrameMap::nof_cpu_regs; i++) {
368 Register r = as_Register(i);
369 if (r != preserve1 && r != preserve2 && r != preserve3 && r != Z_SP && r != Z_thread) {
370 if (dead_value == noreg) {
371 load_const_optimized(r, 0xc1dead);
372 dead_value = r;
373 } else {
374 z_lgr(r, dead_value);
375 }
376 }
377 }
378 }
379
380 #endif // !PRODUCT