1 /*
2 * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "c1/c1_CodeStubs.hpp"
27 #include "c1/c1_FrameMap.hpp"
28 #include "c1/c1_LIRAssembler.hpp"
29 #include "c1/c1_MacroAssembler.hpp"
30 #include "c1/c1_Runtime1.hpp"
31 #include "nativeInst_x86.hpp"
32 #include "oops/objArrayKlass.hpp"
33 #include "runtime/sharedRuntime.hpp"
34 #include "utilities/align.hpp"
35 #include "utilities/macros.hpp"
36 #include "vmreg_x86.inline.hpp"
37
38
39 #define __ ce->masm()->
40
41 float ConversionStub::float_zero = 0.0;
42 double ConversionStub::double_zero = 0.0;
43
44 void ConversionStub::emit_code(LIR_Assembler* ce) {
45 __ bind(_entry);
46 assert(bytecode() == Bytecodes::_f2i || bytecode() == Bytecodes::_d2i, "other conversions do not require stub");
47
48
49 if (input()->is_single_xmm()) {
50 __ comiss(input()->as_xmm_float_reg(),
51 ExternalAddress((address)&float_zero));
52 } else if (input()->is_double_xmm()) {
53 __ comisd(input()->as_xmm_double_reg(),
54 ExternalAddress((address)&double_zero));
55 } else {
56 LP64_ONLY(ShouldNotReachHere());
57 __ push(rax);
58 __ ftst();
59 __ fnstsw_ax();
60 __ sahf();
61 __ pop(rax);
62 }
63
64 Label NaN, do_return;
65 __ jccb(Assembler::parity, NaN);
66 __ jccb(Assembler::below, do_return);
67
68 // input is > 0 -> return maxInt
69 // result register already contains 0x80000000, so subtracting 1 gives 0x7fffffff
70 __ decrement(result()->as_register());
71 __ jmpb(do_return);
72
73 // input is NaN -> return 0
74 __ bind(NaN);
75 __ xorptr(result()->as_register(), result()->as_register());
76
77 __ bind(do_return);
78 __ jmp(_continuation);
79 }
80
81 void CounterOverflowStub::emit_code(LIR_Assembler* ce) {
82 __ bind(_entry);
83 Metadata *m = _method->as_constant_ptr()->as_metadata();
84 ce->store_parameter(m, 1);
85 ce->store_parameter(_bci, 0);
86 __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::counter_overflow_id)));
87 ce->add_call_info_here(_info);
88 ce->verify_oop_map(_info);
89 __ jmp(_continuation);
90 }
91
92 RangeCheckStub::RangeCheckStub(CodeEmitInfo* info, LIR_Opr index, LIR_Opr array)
93 : _index(index), _array(array), _throw_index_out_of_bounds_exception(false) {
94 assert(info != NULL, "must have info");
95 _info = new CodeEmitInfo(info);
96 }
97
98 RangeCheckStub::RangeCheckStub(CodeEmitInfo* info, LIR_Opr index)
99 : _index(index), _array(NULL), _throw_index_out_of_bounds_exception(true) {
100 assert(info != NULL, "must have info");
101 _info = new CodeEmitInfo(info);
102 }
103
104 void RangeCheckStub::emit_code(LIR_Assembler* ce) {
105 __ bind(_entry);
106 if (_info->deoptimize_on_exception()) {
107 address a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
108 __ call(RuntimeAddress(a));
109 ce->add_call_info_here(_info);
110 ce->verify_oop_map(_info);
111 debug_only(__ should_not_reach_here());
112 return;
113 }
114
115 // pass the array index on stack because all registers must be preserved
116 if (_index->is_cpu_register()) {
117 ce->store_parameter(_index->as_register(), 0);
118 } else {
119 ce->store_parameter(_index->as_jint(), 0);
120 }
121 Runtime1::StubID stub_id;
122 if (_throw_index_out_of_bounds_exception) {
123 stub_id = Runtime1::throw_index_exception_id;
124 } else {
125 stub_id = Runtime1::throw_range_check_failed_id;
126 ce->store_parameter(_array->as_pointer_register(), 1);
127 }
128 __ call(RuntimeAddress(Runtime1::entry_for(stub_id)));
129 ce->add_call_info_here(_info);
130 ce->verify_oop_map(_info);
131 debug_only(__ should_not_reach_here());
132 }
133
134 PredicateFailedStub::PredicateFailedStub(CodeEmitInfo* info) {
135 _info = new CodeEmitInfo(info);
136 }
137
138 void PredicateFailedStub::emit_code(LIR_Assembler* ce) {
139 __ bind(_entry);
140 address a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
141 __ call(RuntimeAddress(a));
142 ce->add_call_info_here(_info);
143 ce->verify_oop_map(_info);
144 debug_only(__ should_not_reach_here());
145 }
146
147 void DivByZeroStub::emit_code(LIR_Assembler* ce) {
148 if (_offset != -1) {
149 ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
150 }
151 __ bind(_entry);
152 __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::throw_div0_exception_id)));
153 ce->add_call_info_here(_info);
154 debug_only(__ should_not_reach_here());
155 }
156
157
158 // Implementation of LoadFlattenedArrayStub
159
160 LoadFlattenedArrayStub::LoadFlattenedArrayStub(LIR_Opr array, LIR_Opr index, LIR_Opr result, CodeEmitInfo* info) {
161 _array = array;
162 _index = index;
163 _result = result;
164 // Tell the register allocator that the runtime call will scratch rax.
165 _scratch_reg = FrameMap::rax_oop_opr;
166 _info = new CodeEmitInfo(info);
167 }
168
169 void LoadFlattenedArrayStub::emit_code(LIR_Assembler* ce) {
170 assert(__ rsp_offset() == 0, "frame size should be fixed");
171 __ bind(_entry);
172 ce->store_parameter(_array->as_register(), 1);
173 ce->store_parameter(_index->as_register(), 0);
174 __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::load_flattened_array_id)));
175 ce->add_call_info_here(_info);
176 ce->verify_oop_map(_info);
177 if (_result->as_register() != rax) {
178 __ movptr(_result->as_register(), rax);
179 }
180 __ jmp(_continuation);
181 }
182
183
184 // Implementation of StoreFlattenedArrayStub
185
186 StoreFlattenedArrayStub::StoreFlattenedArrayStub(LIR_Opr array, LIR_Opr index, LIR_Opr value, CodeEmitInfo* info) {
187 _array = array;
188 _index = index;
189 _value = value;
190 _info = new CodeEmitInfo(info);
191 }
192
193
194 void StoreFlattenedArrayStub::emit_code(LIR_Assembler* ce) {
195 assert(__ rsp_offset() == 0, "frame size should be fixed");
196 __ bind(_entry);
197 ce->store_parameter(_array->as_register(), 2);
198 ce->store_parameter(_index->as_register(), 1);
199 ce->store_parameter(_value->as_register(), 0);
200 __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::store_flattened_array_id)));
201 ce->add_call_info_here(_info);
202 ce->verify_oop_map(_info);
203 __ jmp(_continuation);
204 }
205
206
207 // Implementation of NewInstanceStub
208
209 NewInstanceStub::NewInstanceStub(LIR_Opr klass_reg, LIR_Opr result, ciInstanceKlass* klass, CodeEmitInfo* info, Runtime1::StubID stub_id) {
210 _result = result;
211 _klass = klass;
212 _klass_reg = klass_reg;
213 _info = new CodeEmitInfo(info);
214 assert(stub_id == Runtime1::new_instance_id ||
215 stub_id == Runtime1::fast_new_instance_id ||
216 stub_id == Runtime1::fast_new_instance_init_check_id,
217 "need new_instance id");
218 _stub_id = stub_id;
219 }
220
221
222 void NewInstanceStub::emit_code(LIR_Assembler* ce) {
223 assert(__ rsp_offset() == 0, "frame size should be fixed");
224 __ bind(_entry);
225 __ movptr(rdx, _klass_reg->as_register());
226 __ call(RuntimeAddress(Runtime1::entry_for(_stub_id)));
227 ce->add_call_info_here(_info);
228 ce->verify_oop_map(_info);
229 assert(_result->as_register() == rax, "result must in rax,");
230 __ jmp(_continuation);
231 }
232
233
234 // Implementation of NewTypeArrayStub
235
236 NewTypeArrayStub::NewTypeArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {
237 _klass_reg = klass_reg;
238 _length = length;
239 _result = result;
240 _info = new CodeEmitInfo(info);
241 }
242
243
244 void NewTypeArrayStub::emit_code(LIR_Assembler* ce) {
245 assert(__ rsp_offset() == 0, "frame size should be fixed");
246 __ bind(_entry);
247 assert(_length->as_register() == rbx, "length must in rbx,");
248 assert(_klass_reg->as_register() == rdx, "klass_reg must in rdx");
249 __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::new_type_array_id)));
250 ce->add_call_info_here(_info);
251 ce->verify_oop_map(_info);
252 assert(_result->as_register() == rax, "result must in rax,");
253 __ jmp(_continuation);
254 }
255
256
257 // Implementation of NewObjectArrayStub
258
259 NewObjectArrayStub::NewObjectArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result,
260 CodeEmitInfo* info, bool is_value_type) {
261 _klass_reg = klass_reg;
262 _result = result;
263 _length = length;
264 _info = new CodeEmitInfo(info);
265 _is_value_type = is_value_type;
266 }
267
268
269 void NewObjectArrayStub::emit_code(LIR_Assembler* ce) {
270 assert(__ rsp_offset() == 0, "frame size should be fixed");
271 __ bind(_entry);
272 assert(_length->as_register() == rbx, "length must in rbx,");
273 assert(_klass_reg->as_register() == rdx, "klass_reg must in rdx");
274 if (_is_value_type) {
275 __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::new_value_array_id)));
276 } else {
277 __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::new_object_array_id)));
278 }
279 ce->add_call_info_here(_info);
280 ce->verify_oop_map(_info);
281 assert(_result->as_register() == rax, "result must in rax,");
282 __ jmp(_continuation);
283 }
284
285
286 // Implementation of MonitorAccessStubs
287
288 MonitorEnterStub::MonitorEnterStub(LIR_Opr obj_reg, LIR_Opr lock_reg, CodeEmitInfo* info, CodeStub* throw_imse_stub, LIR_Opr scratch_reg)
289 : MonitorAccessStub(obj_reg, lock_reg)
290 {
291 _info = new CodeEmitInfo(info);
292 _throw_imse_stub = throw_imse_stub;
293 _scratch_reg = scratch_reg;
294 if (_throw_imse_stub != NULL) {
295 assert(_scratch_reg != LIR_OprFact::illegalOpr, "must be");
296 }
297 }
298
299
300 void MonitorEnterStub::emit_code(LIR_Assembler* ce) {
301 assert(__ rsp_offset() == 0, "frame size should be fixed");
302 __ bind(_entry);
303 if (_throw_imse_stub != NULL) {
304 // When we come here, _obj_reg has already been checked to be non-null.
305 Register mark = _scratch_reg->as_register();
306 __ movptr(mark, Address(_obj_reg->as_register(), oopDesc::mark_offset_in_bytes()));
307 __ testl(mark, markOopDesc::always_locked_pattern);
308 __ jcc(Assembler::notZero, *_throw_imse_stub->entry());
309 }
310 ce->store_parameter(_obj_reg->as_register(), 1);
311 ce->store_parameter(_lock_reg->as_register(), 0);
312 Runtime1::StubID enter_id;
313 if (ce->compilation()->has_fpu_code()) {
314 enter_id = Runtime1::monitorenter_id;
315 } else {
316 enter_id = Runtime1::monitorenter_nofpu_id;
317 }
318 __ call(RuntimeAddress(Runtime1::entry_for(enter_id)));
319 ce->add_call_info_here(_info);
320 ce->verify_oop_map(_info);
321 __ jmp(_continuation);
322 }
323
324
325 void MonitorExitStub::emit_code(LIR_Assembler* ce) {
326 __ bind(_entry);
327 if (_compute_lock) {
328 // lock_reg was destroyed by fast unlocking attempt => recompute it
329 ce->monitor_address(_monitor_ix, _lock_reg);
330 }
331 ce->store_parameter(_lock_reg->as_register(), 0);
332 // note: non-blocking leaf routine => no call info needed
333 Runtime1::StubID exit_id;
334 if (ce->compilation()->has_fpu_code()) {
335 exit_id = Runtime1::monitorexit_id;
336 } else {
337 exit_id = Runtime1::monitorexit_nofpu_id;
338 }
339 __ call(RuntimeAddress(Runtime1::entry_for(exit_id)));
340 __ jmp(_continuation);
341 }
342
343
344 // Implementation of patching:
345 // - Copy the code at given offset to an inlined buffer (first the bytes, then the number of bytes)
346 // - Replace original code with a call to the stub
347 // At Runtime:
348 // - call to stub, jump to runtime
349 // - in runtime: preserve all registers (rspecially objects, i.e., source and destination object)
350 // - in runtime: after initializing class, restore original code, reexecute instruction
351
352 int PatchingStub::_patch_info_offset = -NativeGeneralJump::instruction_size;
353
354 void PatchingStub::align_patch_site(MacroAssembler* masm) {
355 // We're patching a 5-7 byte instruction on intel and we need to
356 // make sure that we don't see a piece of the instruction. It
357 // appears mostly impossible on Intel to simply invalidate other
358 // processors caches and since they may do aggressive prefetch it's
359 // very hard to make a guess about what code might be in the icache.
360 // Force the instruction to be double word aligned so that it
361 // doesn't span a cache line.
362 masm->align(align_up((int)NativeGeneralJump::instruction_size, wordSize));
363 }
364
365 void PatchingStub::emit_code(LIR_Assembler* ce) {
366 assert(NativeCall::instruction_size <= _bytes_to_copy && _bytes_to_copy <= 0xFF, "not enough room for call");
367
368 Label call_patch;
369
370 // static field accesses have special semantics while the class
371 // initializer is being run so we emit a test which can be used to
372 // check that this code is being executed by the initializing
373 // thread.
374 address being_initialized_entry = __ pc();
375 if (CommentedAssembly) {
376 __ block_comment(" patch template");
377 }
378 if (_id == load_klass_id) {
379 // produce a copy of the load klass instruction for use by the being initialized case
380 #ifdef ASSERT
381 address start = __ pc();
382 #endif
383 Metadata* o = NULL;
384 __ mov_metadata(_obj, o);
385 #ifdef ASSERT
386 for (int i = 0; i < _bytes_to_copy; i++) {
387 address ptr = (address)(_pc_start + i);
388 int a_byte = (*ptr) & 0xFF;
389 assert(a_byte == *start++, "should be the same code");
390 }
391 #endif
392 } else if (_id == load_mirror_id) {
393 // produce a copy of the load mirror instruction for use by the being
394 // initialized case
395 #ifdef ASSERT
396 address start = __ pc();
397 #endif
398 jobject o = NULL;
399 __ movoop(_obj, o);
400 #ifdef ASSERT
401 for (int i = 0; i < _bytes_to_copy; i++) {
402 address ptr = (address)(_pc_start + i);
403 int a_byte = (*ptr) & 0xFF;
404 assert(a_byte == *start++, "should be the same code");
405 }
406 #endif
407 } else {
408 // make a copy the code which is going to be patched.
409 for (int i = 0; i < _bytes_to_copy; i++) {
410 address ptr = (address)(_pc_start + i);
411 int a_byte = (*ptr) & 0xFF;
412 __ emit_int8(a_byte);
413 *ptr = 0x90; // make the site look like a nop
414 }
415 }
416
417 address end_of_patch = __ pc();
418 int bytes_to_skip = 0;
419 if (_id == load_mirror_id) {
420 int offset = __ offset();
421 if (CommentedAssembly) {
422 __ block_comment(" being_initialized check");
423 }
424 assert(_obj != noreg, "must be a valid register");
425 Register tmp = rax;
426 Register tmp2 = rbx;
427 __ push(tmp);
428 __ push(tmp2);
429 // Load without verification to keep code size small. We need it because
430 // begin_initialized_entry_offset has to fit in a byte. Also, we know it's not null.
431 __ movptr(tmp2, Address(_obj, java_lang_Class::klass_offset_in_bytes()));
432 __ get_thread(tmp);
433 __ cmpptr(tmp, Address(tmp2, InstanceKlass::init_thread_offset()));
434 __ pop(tmp2);
435 __ pop(tmp);
436 __ jcc(Assembler::notEqual, call_patch);
437
438 // access_field patches may execute the patched code before it's
439 // copied back into place so we need to jump back into the main
440 // code of the nmethod to continue execution.
441 __ jmp(_patch_site_continuation);
442
443 // make sure this extra code gets skipped
444 bytes_to_skip += __ offset() - offset;
445 }
446 if (CommentedAssembly) {
447 __ block_comment("patch data encoded as movl");
448 }
449 // Now emit the patch record telling the runtime how to find the
450 // pieces of the patch. We only need 3 bytes but for readability of
451 // the disassembly we make the data look like a movl reg, imm32,
452 // which requires 5 bytes
453 int sizeof_patch_record = 5;
454 bytes_to_skip += sizeof_patch_record;
455
456 // emit the offsets needed to find the code to patch
457 int being_initialized_entry_offset = __ pc() - being_initialized_entry + sizeof_patch_record;
458
459 __ emit_int8((unsigned char)0xB8);
460 __ emit_int8(0);
461 __ emit_int8(being_initialized_entry_offset);
462 __ emit_int8(bytes_to_skip);
463 __ emit_int8(_bytes_to_copy);
464 address patch_info_pc = __ pc();
465 assert(patch_info_pc - end_of_patch == bytes_to_skip, "incorrect patch info");
466
467 address entry = __ pc();
468 NativeGeneralJump::insert_unconditional((address)_pc_start, entry);
469 address target = NULL;
470 relocInfo::relocType reloc_type = relocInfo::none;
471 switch (_id) {
472 case access_field_id: target = Runtime1::entry_for(Runtime1::access_field_patching_id); break;
473 case load_klass_id: target = Runtime1::entry_for(Runtime1::load_klass_patching_id); reloc_type = relocInfo::metadata_type; break;
474 case load_mirror_id: target = Runtime1::entry_for(Runtime1::load_mirror_patching_id); reloc_type = relocInfo::oop_type; break;
475 case load_appendix_id: target = Runtime1::entry_for(Runtime1::load_appendix_patching_id); reloc_type = relocInfo::oop_type; break;
476 default: ShouldNotReachHere();
477 }
478 __ bind(call_patch);
479
480 if (CommentedAssembly) {
481 __ block_comment("patch entry point");
482 }
483 __ call(RuntimeAddress(target));
484 assert(_patch_info_offset == (patch_info_pc - __ pc()), "must not change");
485 ce->add_call_info_here(_info);
486 int jmp_off = __ offset();
487 __ jmp(_patch_site_entry);
488 // Add enough nops so deoptimization can overwrite the jmp above with a call
489 // and not destroy the world. We cannot use fat nops here, since the concurrent
490 // code rewrite may transiently create the illegal instruction sequence.
491 for (int j = __ offset() ; j < jmp_off + 5 ; j++ ) {
492 __ nop();
493 }
494 if (_id == load_klass_id || _id == load_mirror_id || _id == load_appendix_id) {
495 CodeSection* cs = __ code_section();
496 RelocIterator iter(cs, (address)_pc_start, (address)(_pc_start + 1));
497 relocInfo::change_reloc_info_for_address(&iter, (address) _pc_start, reloc_type, relocInfo::none);
498 }
499 }
500
501
502 void DeoptimizeStub::emit_code(LIR_Assembler* ce) {
503 __ bind(_entry);
504 ce->store_parameter(_trap_request, 0);
505 __ call(RuntimeAddress(Runtime1::entry_for(Runtime1::deoptimize_id)));
506 ce->add_call_info_here(_info);
507 DEBUG_ONLY(__ should_not_reach_here());
508 }
509
510
511 void ImplicitNullCheckStub::emit_code(LIR_Assembler* ce) {
512 address a;
513 if (_info->deoptimize_on_exception()) {
514 // Deoptimize, do not throw the exception, because it is probably wrong to do it here.
515 a = Runtime1::entry_for(Runtime1::predicate_failed_trap_id);
516 } else {
517 a = Runtime1::entry_for(Runtime1::throw_null_pointer_exception_id);
518 }
519
520 ce->compilation()->implicit_exception_table()->append(_offset, __ offset());
521 __ bind(_entry);
522 __ call(RuntimeAddress(a));
523 ce->add_call_info_here(_info);
524 ce->verify_oop_map(_info);
525 debug_only(__ should_not_reach_here());
526 }
527
528
529 void SimpleExceptionStub::emit_code(LIR_Assembler* ce) {
530 assert(__ rsp_offset() == 0, "frame size should be fixed");
531
532 __ bind(_entry);
533 // pass the object on stack because all registers must be preserved
534 if (_obj->is_cpu_register()) {
535 ce->store_parameter(_obj->as_register(), 0);
536 }
537 __ call(RuntimeAddress(Runtime1::entry_for(_stub)));
538 ce->add_call_info_here(_info);
539 debug_only(__ should_not_reach_here());
540 }
541
542
543 void ArrayCopyStub::emit_code(LIR_Assembler* ce) {
544 //---------------slow case: call to native-----------------
545 __ bind(_entry);
546 // Figure out where the args should go
547 // This should really convert the IntrinsicID to the Method* and signature
548 // but I don't know how to do that.
549 //
550 VMRegPair args[5];
551 BasicType signature[5] = { T_OBJECT, T_INT, T_OBJECT, T_INT, T_INT};
552 SharedRuntime::java_calling_convention(signature, args, 5, true);
553
554 // push parameters
555 // (src, src_pos, dest, destPos, length)
556 Register r[5];
557 r[0] = src()->as_register();
558 r[1] = src_pos()->as_register();
559 r[2] = dst()->as_register();
560 r[3] = dst_pos()->as_register();
561 r[4] = length()->as_register();
562
563 // next registers will get stored on the stack
564 for (int i = 0; i < 5 ; i++ ) {
565 VMReg r_1 = args[i].first();
566 if (r_1->is_stack()) {
567 int st_off = r_1->reg2stack() * wordSize;
568 __ movptr (Address(rsp, st_off), r[i]);
569 } else {
570 assert(r[i] == args[i].first()->as_Register(), "Wrong register for arg ");
571 }
572 }
573
574 ce->align_call(lir_static_call);
575
576 ce->emit_static_call_stub();
577 if (ce->compilation()->bailed_out()) {
578 return; // CodeCache is full
579 }
580 AddressLiteral resolve(SharedRuntime::get_resolve_static_call_stub(),
581 relocInfo::static_call_type);
582 __ call(resolve);
583 ce->add_call_info_here(info());
584
585 #ifndef PRODUCT
586 __ incrementl(ExternalAddress((address)&Runtime1::_arraycopy_slowcase_cnt));
587 #endif
588
589 __ jmp(_continuation);
590 }
591
592 #undef __