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