Mercurial > hg > truffle
annotate src/cpu/sparc/vm/nativeInst_sparc.cpp @ 670:c7bbabdcadfb
Merge
author | phh |
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date | Tue, 24 Mar 2009 19:05:23 -0700 |
parents | d1605aabd0a1 |
children | 6b2273dd6fa9 |
rev | line source |
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0 | 1 /* |
196 | 2 * Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved. |
0 | 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 # include "incls/_precompiled.incl" | |
26 # include "incls/_nativeInst_sparc.cpp.incl" | |
27 | |
28 | |
116
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29 bool NativeInstruction::is_dtrace_trap() { |
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30 return !is_nop(); |
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31 } |
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32 |
0 | 33 void NativeInstruction::set_data64_sethi(address instaddr, intptr_t x) { |
34 ResourceMark rm; | |
35 CodeBuffer buf(instaddr, 10 * BytesPerInstWord ); | |
36 MacroAssembler* _masm = new MacroAssembler(&buf); | |
37 Register destreg; | |
38 | |
39 destreg = inv_rd(*(unsigned int *)instaddr); | |
40 // Generate a the new sequence | |
41 Address dest( destreg, (address)x ); | |
42 _masm->sethi( dest, true ); | |
43 ICache::invalidate_range(instaddr, 7 * BytesPerInstWord); | |
44 } | |
45 | |
46 void NativeInstruction::verify() { | |
47 // make sure code pattern is actually an instruction address | |
48 address addr = addr_at(0); | |
49 if (addr == 0 || ((intptr_t)addr & 3) != 0) { | |
50 fatal("not an instruction address"); | |
51 } | |
52 } | |
53 | |
54 void NativeInstruction::print() { | |
55 tty->print_cr(INTPTR_FORMAT ": 0x%x", addr_at(0), long_at(0)); | |
56 } | |
57 | |
58 void NativeInstruction::set_long_at(int offset, int i) { | |
59 address addr = addr_at(offset); | |
60 *(int*)addr = i; | |
61 ICache::invalidate_word(addr); | |
62 } | |
63 | |
64 void NativeInstruction::set_jlong_at(int offset, jlong i) { | |
65 address addr = addr_at(offset); | |
66 *(jlong*)addr = i; | |
67 // Don't need to invalidate 2 words here, because | |
68 // the flush instruction operates on doublewords. | |
69 ICache::invalidate_word(addr); | |
70 } | |
71 | |
72 void NativeInstruction::set_addr_at(int offset, address x) { | |
73 address addr = addr_at(offset); | |
74 assert( ((intptr_t)addr & (wordSize-1)) == 0, "set_addr_at bad address alignment"); | |
75 *(uintptr_t*)addr = (uintptr_t)x; | |
76 // Don't need to invalidate 2 words here in the 64-bit case, | |
77 // because the flush instruction operates on doublewords. | |
78 ICache::invalidate_word(addr); | |
79 // The Intel code has this assertion for NativeCall::set_destination, | |
80 // NativeMovConstReg::set_data, NativeMovRegMem::set_offset, | |
81 // NativeJump::set_jump_destination, and NativePushImm32::set_data | |
82 //assert (Patching_lock->owned_by_self(), "must hold lock to patch instruction") | |
83 } | |
84 | |
85 bool NativeInstruction::is_zero_test(Register ®) { | |
86 int x = long_at(0); | |
87 Assembler::op3s temp = (Assembler::op3s) (Assembler::sub_op3 | Assembler::cc_bit_op3); | |
88 if (is_op3(x, temp, Assembler::arith_op) && | |
89 inv_immed(x) && inv_rd(x) == G0) { | |
90 if (inv_rs1(x) == G0) { | |
91 reg = inv_rs2(x); | |
92 return true; | |
93 } else if (inv_rs2(x) == G0) { | |
94 reg = inv_rs1(x); | |
95 return true; | |
96 } | |
97 } | |
98 return false; | |
99 } | |
100 | |
101 bool NativeInstruction::is_load_store_with_small_offset(Register reg) { | |
102 int x = long_at(0); | |
103 if (is_op(x, Assembler::ldst_op) && | |
104 inv_rs1(x) == reg && inv_immed(x)) { | |
105 return true; | |
106 } | |
107 return false; | |
108 } | |
109 | |
110 void NativeCall::verify() { | |
111 NativeInstruction::verify(); | |
112 // make sure code pattern is actually a call instruction | |
113 if (!is_op(long_at(0), Assembler::call_op)) { | |
114 fatal("not a call"); | |
115 } | |
116 } | |
117 | |
118 void NativeCall::print() { | |
119 tty->print_cr(INTPTR_FORMAT ": call " INTPTR_FORMAT, instruction_address(), destination()); | |
120 } | |
121 | |
122 | |
123 // MT-safe patching of a call instruction (and following word). | |
124 // First patches the second word, and then atomicly replaces | |
125 // the first word with the first new instruction word. | |
126 // Other processors might briefly see the old first word | |
127 // followed by the new second word. This is OK if the old | |
128 // second word is harmless, and the new second word may be | |
129 // harmlessly executed in the delay slot of the call. | |
130 void NativeCall::replace_mt_safe(address instr_addr, address code_buffer) { | |
131 assert(Patching_lock->is_locked() || | |
132 SafepointSynchronize::is_at_safepoint(), "concurrent code patching"); | |
133 assert (instr_addr != NULL, "illegal address for code patching"); | |
134 NativeCall* n_call = nativeCall_at (instr_addr); // checking that it is a call | |
135 assert(NativeCall::instruction_size == 8, "wrong instruction size; must be 8"); | |
136 int i0 = ((int*)code_buffer)[0]; | |
137 int i1 = ((int*)code_buffer)[1]; | |
138 int* contention_addr = (int*) n_call->addr_at(1*BytesPerInstWord); | |
139 assert(inv_op(*contention_addr) == Assembler::arith_op || | |
140 *contention_addr == nop_instruction() || !VM_Version::v9_instructions_work(), | |
141 "must not interfere with original call"); | |
142 // The set_long_at calls do the ICacheInvalidate so we just need to do them in reverse order | |
143 n_call->set_long_at(1*BytesPerInstWord, i1); | |
144 n_call->set_long_at(0*BytesPerInstWord, i0); | |
145 // NOTE: It is possible that another thread T will execute | |
146 // only the second patched word. | |
147 // In other words, since the original instruction is this | |
148 // call patching_stub; nop (NativeCall) | |
149 // and the new sequence from the buffer is this: | |
150 // sethi %hi(K), %r; add %r, %lo(K), %r (NativeMovConstReg) | |
151 // what T will execute is this: | |
152 // call patching_stub; add %r, %lo(K), %r | |
153 // thereby putting garbage into %r before calling the patching stub. | |
154 // This is OK, because the patching stub ignores the value of %r. | |
155 | |
156 // Make sure the first-patched instruction, which may co-exist | |
157 // briefly with the call, will do something harmless. | |
158 assert(inv_op(*contention_addr) == Assembler::arith_op || | |
159 *contention_addr == nop_instruction() || !VM_Version::v9_instructions_work(), | |
160 "must not interfere with original call"); | |
161 } | |
162 | |
163 // Similar to replace_mt_safe, but just changes the destination. The | |
164 // important thing is that free-running threads are able to execute this | |
165 // call instruction at all times. Thus, the displacement field must be | |
166 // instruction-word-aligned. This is always true on SPARC. | |
167 // | |
168 // Used in the runtime linkage of calls; see class CompiledIC. | |
169 void NativeCall::set_destination_mt_safe(address dest) { | |
170 assert(Patching_lock->is_locked() || | |
171 SafepointSynchronize::is_at_safepoint(), "concurrent code patching"); | |
172 // set_destination uses set_long_at which does the ICache::invalidate | |
173 set_destination(dest); | |
174 } | |
175 | |
176 // Code for unit testing implementation of NativeCall class | |
177 void NativeCall::test() { | |
178 #ifdef ASSERT | |
179 ResourceMark rm; | |
180 CodeBuffer cb("test", 100, 100); | |
181 MacroAssembler* a = new MacroAssembler(&cb); | |
182 NativeCall *nc; | |
183 uint idx; | |
184 int offsets[] = { | |
185 0x0, | |
186 0xfffffff0, | |
187 0x7ffffff0, | |
188 0x80000000, | |
189 0x20, | |
190 0x4000, | |
191 }; | |
192 | |
193 VM_Version::allow_all(); | |
194 | |
195 a->call( a->pc(), relocInfo::none ); | |
196 a->delayed()->nop(); | |
197 nc = nativeCall_at( cb.code_begin() ); | |
198 nc->print(); | |
199 | |
200 nc = nativeCall_overwriting_at( nc->next_instruction_address() ); | |
201 for (idx = 0; idx < ARRAY_SIZE(offsets); idx++) { | |
202 nc->set_destination( cb.code_begin() + offsets[idx] ); | |
203 assert(nc->destination() == (cb.code_begin() + offsets[idx]), "check unit test"); | |
204 nc->print(); | |
205 } | |
206 | |
207 nc = nativeCall_before( cb.code_begin() + 8 ); | |
208 nc->print(); | |
209 | |
210 VM_Version::revert(); | |
211 #endif | |
212 } | |
213 // End code for unit testing implementation of NativeCall class | |
214 | |
215 //------------------------------------------------------------------- | |
216 | |
217 #ifdef _LP64 | |
218 | |
219 void NativeFarCall::set_destination(address dest) { | |
220 // Address materialized in the instruction stream, so nothing to do. | |
221 return; | |
222 #if 0 // What we'd do if we really did want to change the destination | |
223 if (destination() == dest) { | |
224 return; | |
225 } | |
226 ResourceMark rm; | |
227 CodeBuffer buf(addr_at(0), instruction_size + 1); | |
228 MacroAssembler* _masm = new MacroAssembler(&buf); | |
229 // Generate the new sequence | |
230 Address(O7, dest); | |
231 _masm->jumpl_to(dest, O7); | |
232 ICache::invalidate_range(addr_at(0), instruction_size ); | |
233 #endif | |
234 } | |
235 | |
236 void NativeFarCall::verify() { | |
237 // make sure code pattern is actually a jumpl_to instruction | |
238 assert((int)instruction_size == (int)NativeJump::instruction_size, "same as jump_to"); | |
239 assert((int)jmpl_offset == (int)NativeMovConstReg::add_offset, "sethi size ok"); | |
240 nativeJump_at(addr_at(0))->verify(); | |
241 } | |
242 | |
243 bool NativeFarCall::is_call_at(address instr) { | |
244 return nativeInstruction_at(instr)->is_sethi(); | |
245 } | |
246 | |
247 void NativeFarCall::print() { | |
248 tty->print_cr(INTPTR_FORMAT ": call " INTPTR_FORMAT, instruction_address(), destination()); | |
249 } | |
250 | |
251 bool NativeFarCall::destination_is_compiled_verified_entry_point() { | |
252 nmethod* callee = CodeCache::find_nmethod(destination()); | |
253 if (callee == NULL) { | |
254 return false; | |
255 } else { | |
256 return destination() == callee->verified_entry_point(); | |
257 } | |
258 } | |
259 | |
260 // MT-safe patching of a far call. | |
261 void NativeFarCall::replace_mt_safe(address instr_addr, address code_buffer) { | |
262 Unimplemented(); | |
263 } | |
264 | |
265 // Code for unit testing implementation of NativeFarCall class | |
266 void NativeFarCall::test() { | |
267 Unimplemented(); | |
268 } | |
269 // End code for unit testing implementation of NativeFarCall class | |
270 | |
271 #endif // _LP64 | |
272 | |
273 //------------------------------------------------------------------- | |
274 | |
275 | |
276 void NativeMovConstReg::verify() { | |
277 NativeInstruction::verify(); | |
278 // make sure code pattern is actually a "set_oop" synthetic instruction | |
279 // see MacroAssembler::set_oop() | |
280 int i0 = long_at(sethi_offset); | |
281 int i1 = long_at(add_offset); | |
282 | |
283 // verify the pattern "sethi %hi22(imm), reg ; add reg, %lo10(imm), reg" | |
284 Register rd = inv_rd(i0); | |
285 #ifndef _LP64 | |
286 if (!(is_op2(i0, Assembler::sethi_op2) && rd != G0 && | |
287 is_op3(i1, Assembler::add_op3, Assembler::arith_op) && | |
288 inv_immed(i1) && (unsigned)get_simm13(i1) < (1 << 10) && | |
289 rd == inv_rs1(i1) && rd == inv_rd(i1))) { | |
290 fatal("not a set_oop"); | |
291 } | |
292 #else | |
293 if (!is_op2(i0, Assembler::sethi_op2) && rd != G0 ) { | |
294 fatal("not a set_oop"); | |
295 } | |
296 #endif | |
297 } | |
298 | |
299 | |
300 void NativeMovConstReg::print() { | |
301 tty->print_cr(INTPTR_FORMAT ": mov reg, " INTPTR_FORMAT, instruction_address(), data()); | |
302 } | |
303 | |
304 | |
305 #ifdef _LP64 | |
306 intptr_t NativeMovConstReg::data() const { | |
307 return data64(addr_at(sethi_offset), long_at(add_offset)); | |
308 } | |
309 #else | |
310 intptr_t NativeMovConstReg::data() const { | |
311 return data32(long_at(sethi_offset), long_at(add_offset)); | |
312 } | |
313 #endif | |
314 | |
315 | |
316 void NativeMovConstReg::set_data(intptr_t x) { | |
317 #ifdef _LP64 | |
318 set_data64_sethi(addr_at(sethi_offset), x); | |
319 #else | |
320 set_long_at(sethi_offset, set_data32_sethi( long_at(sethi_offset), x)); | |
321 #endif | |
322 set_long_at(add_offset, set_data32_simm13( long_at(add_offset), x)); | |
323 | |
324 // also store the value into an oop_Relocation cell, if any | |
325 CodeBlob* nm = CodeCache::find_blob(instruction_address()); | |
326 if (nm != NULL) { | |
327 RelocIterator iter(nm, instruction_address(), next_instruction_address()); | |
328 oop* oop_addr = NULL; | |
329 while (iter.next()) { | |
330 if (iter.type() == relocInfo::oop_type) { | |
331 oop_Relocation *r = iter.oop_reloc(); | |
332 if (oop_addr == NULL) { | |
333 oop_addr = r->oop_addr(); | |
334 *oop_addr = (oop)x; | |
335 } else { | |
336 assert(oop_addr == r->oop_addr(), "must be only one set-oop here"); | |
337 } | |
338 } | |
339 } | |
340 } | |
341 } | |
342 | |
343 | |
344 // Code for unit testing implementation of NativeMovConstReg class | |
345 void NativeMovConstReg::test() { | |
346 #ifdef ASSERT | |
347 ResourceMark rm; | |
348 CodeBuffer cb("test", 100, 100); | |
349 MacroAssembler* a = new MacroAssembler(&cb); | |
350 NativeMovConstReg* nm; | |
351 uint idx; | |
352 int offsets[] = { | |
353 0x0, | |
354 0x7fffffff, | |
355 0x80000000, | |
356 0xffffffff, | |
357 0x20, | |
358 4096, | |
359 4097, | |
360 }; | |
361 | |
362 VM_Version::allow_all(); | |
363 | |
364 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); | |
365 a->add(I3, low10(0xaaaabbbb), I3); | |
366 a->sethi(0xccccdddd, O2, true, RelocationHolder::none); | |
367 a->add(O2, low10(0xccccdddd), O2); | |
368 | |
369 nm = nativeMovConstReg_at( cb.code_begin() ); | |
370 nm->print(); | |
371 | |
372 nm = nativeMovConstReg_at( nm->next_instruction_address() ); | |
373 for (idx = 0; idx < ARRAY_SIZE(offsets); idx++) { | |
374 nm->set_data( offsets[idx] ); | |
375 assert(nm->data() == offsets[idx], "check unit test"); | |
376 } | |
377 nm->print(); | |
378 | |
379 VM_Version::revert(); | |
380 #endif | |
381 } | |
382 // End code for unit testing implementation of NativeMovConstReg class | |
383 | |
384 //------------------------------------------------------------------- | |
385 | |
386 void NativeMovConstRegPatching::verify() { | |
387 NativeInstruction::verify(); | |
388 // Make sure code pattern is sethi/nop/add. | |
389 int i0 = long_at(sethi_offset); | |
390 int i1 = long_at(nop_offset); | |
391 int i2 = long_at(add_offset); | |
392 assert((int)nop_offset == (int)NativeMovConstReg::add_offset, "sethi size ok"); | |
393 | |
394 // Verify the pattern "sethi %hi22(imm), reg; nop; add reg, %lo10(imm), reg" | |
395 // The casual reader should note that on Sparc a nop is a special case if sethi | |
396 // in which the destination register is %g0. | |
397 Register rd0 = inv_rd(i0); | |
398 Register rd1 = inv_rd(i1); | |
399 if (!(is_op2(i0, Assembler::sethi_op2) && rd0 != G0 && | |
400 is_op2(i1, Assembler::sethi_op2) && rd1 == G0 && // nop is a special case of sethi | |
401 is_op3(i2, Assembler::add_op3, Assembler::arith_op) && | |
402 inv_immed(i2) && (unsigned)get_simm13(i2) < (1 << 10) && | |
403 rd0 == inv_rs1(i2) && rd0 == inv_rd(i2))) { | |
404 fatal("not a set_oop"); | |
405 } | |
406 } | |
407 | |
408 | |
409 void NativeMovConstRegPatching::print() { | |
410 tty->print_cr(INTPTR_FORMAT ": mov reg, " INTPTR_FORMAT, instruction_address(), data()); | |
411 } | |
412 | |
413 | |
414 int NativeMovConstRegPatching::data() const { | |
415 #ifdef _LP64 | |
416 return data64(addr_at(sethi_offset), long_at(add_offset)); | |
417 #else | |
418 return data32(long_at(sethi_offset), long_at(add_offset)); | |
419 #endif | |
420 } | |
421 | |
422 | |
423 void NativeMovConstRegPatching::set_data(int x) { | |
424 #ifdef _LP64 | |
425 set_data64_sethi(addr_at(sethi_offset), x); | |
426 #else | |
427 set_long_at(sethi_offset, set_data32_sethi(long_at(sethi_offset), x)); | |
428 #endif | |
429 set_long_at(add_offset, set_data32_simm13(long_at(add_offset), x)); | |
430 | |
431 // also store the value into an oop_Relocation cell, if any | |
432 CodeBlob* nm = CodeCache::find_blob(instruction_address()); | |
433 if (nm != NULL) { | |
434 RelocIterator iter(nm, instruction_address(), next_instruction_address()); | |
435 oop* oop_addr = NULL; | |
436 while (iter.next()) { | |
437 if (iter.type() == relocInfo::oop_type) { | |
438 oop_Relocation *r = iter.oop_reloc(); | |
439 if (oop_addr == NULL) { | |
440 oop_addr = r->oop_addr(); | |
441 *oop_addr = (oop)x; | |
442 } else { | |
443 assert(oop_addr == r->oop_addr(), "must be only one set-oop here"); | |
444 } | |
445 } | |
446 } | |
447 } | |
448 } | |
449 | |
450 | |
451 // Code for unit testing implementation of NativeMovConstRegPatching class | |
452 void NativeMovConstRegPatching::test() { | |
453 #ifdef ASSERT | |
454 ResourceMark rm; | |
455 CodeBuffer cb("test", 100, 100); | |
456 MacroAssembler* a = new MacroAssembler(&cb); | |
457 NativeMovConstRegPatching* nm; | |
458 uint idx; | |
459 int offsets[] = { | |
460 0x0, | |
461 0x7fffffff, | |
462 0x80000000, | |
463 0xffffffff, | |
464 0x20, | |
465 4096, | |
466 4097, | |
467 }; | |
468 | |
469 VM_Version::allow_all(); | |
470 | |
471 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); | |
472 a->nop(); | |
473 a->add(I3, low10(0xaaaabbbb), I3); | |
474 a->sethi(0xccccdddd, O2, true, RelocationHolder::none); | |
475 a->nop(); | |
476 a->add(O2, low10(0xccccdddd), O2); | |
477 | |
478 nm = nativeMovConstRegPatching_at( cb.code_begin() ); | |
479 nm->print(); | |
480 | |
481 nm = nativeMovConstRegPatching_at( nm->next_instruction_address() ); | |
482 for (idx = 0; idx < ARRAY_SIZE(offsets); idx++) { | |
483 nm->set_data( offsets[idx] ); | |
484 assert(nm->data() == offsets[idx], "check unit test"); | |
485 } | |
486 nm->print(); | |
487 | |
488 VM_Version::revert(); | |
489 #endif // ASSERT | |
490 } | |
491 // End code for unit testing implementation of NativeMovConstRegPatching class | |
492 | |
493 | |
494 //------------------------------------------------------------------- | |
495 | |
496 | |
497 void NativeMovRegMem::copy_instruction_to(address new_instruction_address) { | |
498 Untested("copy_instruction_to"); | |
499 int instruction_size = next_instruction_address() - instruction_address(); | |
500 for (int i = 0; i < instruction_size; i += BytesPerInstWord) { | |
501 *(int*)(new_instruction_address + i) = *(int*)(address(this) + i); | |
502 } | |
503 } | |
504 | |
505 | |
506 void NativeMovRegMem::verify() { | |
507 NativeInstruction::verify(); | |
508 // make sure code pattern is actually a "ld" or "st" of some sort. | |
509 int i0 = long_at(0); | |
510 int op3 = inv_op3(i0); | |
511 | |
512 assert((int)add_offset == NativeMovConstReg::add_offset, "sethi size ok"); | |
513 | |
514 if (!(is_op(i0, Assembler::ldst_op) && | |
515 inv_immed(i0) && | |
516 0 != (op3 < op3_ldst_int_limit | |
517 ? (1 << op3 ) & (op3_mask_ld | op3_mask_st) | |
518 : (1 << (op3 - op3_ldst_int_limit)) & (op3_mask_ldf | op3_mask_stf)))) | |
519 { | |
520 int i1 = long_at(ldst_offset); | |
521 Register rd = inv_rd(i0); | |
522 | |
523 op3 = inv_op3(i1); | |
524 if (!is_op(i1, Assembler::ldst_op) && rd == inv_rs2(i1) && | |
525 0 != (op3 < op3_ldst_int_limit | |
526 ? (1 << op3 ) & (op3_mask_ld | op3_mask_st) | |
527 : (1 << (op3 - op3_ldst_int_limit)) & (op3_mask_ldf | op3_mask_stf))) { | |
528 fatal("not a ld* or st* op"); | |
529 } | |
530 } | |
531 } | |
532 | |
533 | |
534 void NativeMovRegMem::print() { | |
535 if (is_immediate()) { | |
536 tty->print_cr(INTPTR_FORMAT ": mov reg, [reg + %x]", instruction_address(), offset()); | |
537 } else { | |
538 tty->print_cr(INTPTR_FORMAT ": mov reg, [reg + reg]", instruction_address()); | |
539 } | |
540 } | |
541 | |
542 | |
543 // Code for unit testing implementation of NativeMovRegMem class | |
544 void NativeMovRegMem::test() { | |
545 #ifdef ASSERT | |
546 ResourceMark rm; | |
547 CodeBuffer cb("test", 1000, 1000); | |
548 MacroAssembler* a = new MacroAssembler(&cb); | |
549 NativeMovRegMem* nm; | |
550 uint idx = 0; | |
551 uint idx1; | |
552 int offsets[] = { | |
553 0x0, | |
554 0xffffffff, | |
555 0x7fffffff, | |
556 0x80000000, | |
557 4096, | |
558 4097, | |
559 0x20, | |
560 0x4000, | |
561 }; | |
562 | |
563 VM_Version::allow_all(); | |
564 | |
565 a->ldsw( G5, low10(0xffffffff), G4 ); idx++; | |
566 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
567 a->ldsw( G5, I3, G4 ); idx++; | |
568 a->ldsb( G5, low10(0xffffffff), G4 ); idx++; | |
569 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
570 a->ldsb( G5, I3, G4 ); idx++; | |
571 a->ldsh( G5, low10(0xffffffff), G4 ); idx++; | |
572 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
573 a->ldsh( G5, I3, G4 ); idx++; | |
574 a->lduw( G5, low10(0xffffffff), G4 ); idx++; | |
575 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
576 a->lduw( G5, I3, G4 ); idx++; | |
577 a->ldub( G5, low10(0xffffffff), G4 ); idx++; | |
578 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
579 a->ldub( G5, I3, G4 ); idx++; | |
580 a->lduh( G5, low10(0xffffffff), G4 ); idx++; | |
581 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
582 a->lduh( G5, I3, G4 ); idx++; | |
583 a->ldx( G5, low10(0xffffffff), G4 ); idx++; | |
584 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
585 a->ldx( G5, I3, G4 ); idx++; | |
586 a->ldd( G5, low10(0xffffffff), G4 ); idx++; | |
587 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
588 a->ldd( G5, I3, G4 ); idx++; | |
589 a->ldf( FloatRegisterImpl::D, O2, -1, F14 ); idx++; | |
590 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
591 a->ldf( FloatRegisterImpl::S, O0, I3, F15 ); idx++; | |
592 | |
593 a->stw( G5, G4, low10(0xffffffff) ); idx++; | |
594 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
595 a->stw( G5, G4, I3 ); idx++; | |
596 a->stb( G5, G4, low10(0xffffffff) ); idx++; | |
597 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
598 a->stb( G5, G4, I3 ); idx++; | |
599 a->sth( G5, G4, low10(0xffffffff) ); idx++; | |
600 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
601 a->sth( G5, G4, I3 ); idx++; | |
602 a->stx( G5, G4, low10(0xffffffff) ); idx++; | |
603 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
604 a->stx( G5, G4, I3 ); idx++; | |
605 a->std( G5, G4, low10(0xffffffff) ); idx++; | |
606 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
607 a->std( G5, G4, I3 ); idx++; | |
608 a->stf( FloatRegisterImpl::S, F18, O2, -1 ); idx++; | |
609 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->add(I3, low10(0xaaaabbbb), I3); | |
610 a->stf( FloatRegisterImpl::S, F15, O0, I3 ); idx++; | |
611 | |
612 nm = nativeMovRegMem_at( cb.code_begin() ); | |
613 nm->print(); | |
614 nm->set_offset( low10(0) ); | |
615 nm->print(); | |
616 nm->add_offset_in_bytes( low10(0xbb) * wordSize ); | |
617 nm->print(); | |
618 | |
619 while (--idx) { | |
620 nm = nativeMovRegMem_at( nm->next_instruction_address() ); | |
621 nm->print(); | |
622 for (idx1 = 0; idx1 < ARRAY_SIZE(offsets); idx1++) { | |
623 nm->set_offset( nm->is_immediate() ? low10(offsets[idx1]) : offsets[idx1] ); | |
624 assert(nm->offset() == (nm->is_immediate() ? low10(offsets[idx1]) : offsets[idx1]), | |
625 "check unit test"); | |
626 nm->print(); | |
627 } | |
628 nm->add_offset_in_bytes( low10(0xbb) * wordSize ); | |
629 nm->print(); | |
630 } | |
631 | |
632 VM_Version::revert(); | |
633 #endif // ASSERT | |
634 } | |
635 | |
636 // End code for unit testing implementation of NativeMovRegMem class | |
637 | |
638 //-------------------------------------------------------------------------------- | |
639 | |
640 | |
641 void NativeMovRegMemPatching::copy_instruction_to(address new_instruction_address) { | |
642 Untested("copy_instruction_to"); | |
643 int instruction_size = next_instruction_address() - instruction_address(); | |
644 for (int i = 0; i < instruction_size; i += wordSize) { | |
645 *(long*)(new_instruction_address + i) = *(long*)(address(this) + i); | |
646 } | |
647 } | |
648 | |
649 | |
650 void NativeMovRegMemPatching::verify() { | |
651 NativeInstruction::verify(); | |
652 // make sure code pattern is actually a "ld" or "st" of some sort. | |
653 int i0 = long_at(0); | |
654 int op3 = inv_op3(i0); | |
655 | |
656 assert((int)nop_offset == (int)NativeMovConstReg::add_offset, "sethi size ok"); | |
657 | |
658 if (!(is_op(i0, Assembler::ldst_op) && | |
659 inv_immed(i0) && | |
660 0 != (op3 < op3_ldst_int_limit | |
661 ? (1 << op3 ) & (op3_mask_ld | op3_mask_st) | |
662 : (1 << (op3 - op3_ldst_int_limit)) & (op3_mask_ldf | op3_mask_stf)))) { | |
663 int i1 = long_at(ldst_offset); | |
664 Register rd = inv_rd(i0); | |
665 | |
666 op3 = inv_op3(i1); | |
667 if (!is_op(i1, Assembler::ldst_op) && rd == inv_rs2(i1) && | |
668 0 != (op3 < op3_ldst_int_limit | |
669 ? (1 << op3 ) & (op3_mask_ld | op3_mask_st) | |
670 : (1 << (op3 - op3_ldst_int_limit)) & (op3_mask_ldf | op3_mask_stf))) { | |
671 fatal("not a ld* or st* op"); | |
672 } | |
673 } | |
674 } | |
675 | |
676 | |
677 void NativeMovRegMemPatching::print() { | |
678 if (is_immediate()) { | |
679 tty->print_cr(INTPTR_FORMAT ": mov reg, [reg + %x]", instruction_address(), offset()); | |
680 } else { | |
681 tty->print_cr(INTPTR_FORMAT ": mov reg, [reg + reg]", instruction_address()); | |
682 } | |
683 } | |
684 | |
685 | |
686 // Code for unit testing implementation of NativeMovRegMemPatching class | |
687 void NativeMovRegMemPatching::test() { | |
688 #ifdef ASSERT | |
689 ResourceMark rm; | |
690 CodeBuffer cb("test", 1000, 1000); | |
691 MacroAssembler* a = new MacroAssembler(&cb); | |
692 NativeMovRegMemPatching* nm; | |
693 uint idx = 0; | |
694 uint idx1; | |
695 int offsets[] = { | |
696 0x0, | |
697 0xffffffff, | |
698 0x7fffffff, | |
699 0x80000000, | |
700 4096, | |
701 4097, | |
702 0x20, | |
703 0x4000, | |
704 }; | |
705 | |
706 VM_Version::allow_all(); | |
707 | |
708 a->ldsw( G5, low10(0xffffffff), G4 ); idx++; | |
709 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
710 a->ldsw( G5, I3, G4 ); idx++; | |
711 a->ldsb( G5, low10(0xffffffff), G4 ); idx++; | |
712 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
713 a->ldsb( G5, I3, G4 ); idx++; | |
714 a->ldsh( G5, low10(0xffffffff), G4 ); idx++; | |
715 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
716 a->ldsh( G5, I3, G4 ); idx++; | |
717 a->lduw( G5, low10(0xffffffff), G4 ); idx++; | |
718 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
719 a->lduw( G5, I3, G4 ); idx++; | |
720 a->ldub( G5, low10(0xffffffff), G4 ); idx++; | |
721 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
722 a->ldub( G5, I3, G4 ); idx++; | |
723 a->lduh( G5, low10(0xffffffff), G4 ); idx++; | |
724 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
725 a->lduh( G5, I3, G4 ); idx++; | |
726 a->ldx( G5, low10(0xffffffff), G4 ); idx++; | |
727 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
728 a->ldx( G5, I3, G4 ); idx++; | |
729 a->ldd( G5, low10(0xffffffff), G4 ); idx++; | |
730 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
731 a->ldd( G5, I3, G4 ); idx++; | |
732 a->ldf( FloatRegisterImpl::D, O2, -1, F14 ); idx++; | |
733 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
734 a->ldf( FloatRegisterImpl::S, O0, I3, F15 ); idx++; | |
735 | |
736 a->stw( G5, G4, low10(0xffffffff) ); idx++; | |
737 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
738 a->stw( G5, G4, I3 ); idx++; | |
739 a->stb( G5, G4, low10(0xffffffff) ); idx++; | |
740 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
741 a->stb( G5, G4, I3 ); idx++; | |
742 a->sth( G5, G4, low10(0xffffffff) ); idx++; | |
743 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
744 a->sth( G5, G4, I3 ); idx++; | |
745 a->stx( G5, G4, low10(0xffffffff) ); idx++; | |
746 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
747 a->stx( G5, G4, I3 ); idx++; | |
748 a->std( G5, G4, low10(0xffffffff) ); idx++; | |
749 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
750 a->std( G5, G4, I3 ); idx++; | |
751 a->stf( FloatRegisterImpl::S, F18, O2, -1 ); idx++; | |
752 a->sethi(0xaaaabbbb, I3, true, RelocationHolder::none); a->nop(); a->add(I3, low10(0xaaaabbbb), I3); | |
753 a->stf( FloatRegisterImpl::S, F15, O0, I3 ); idx++; | |
754 | |
755 nm = nativeMovRegMemPatching_at( cb.code_begin() ); | |
756 nm->print(); | |
757 nm->set_offset( low10(0) ); | |
758 nm->print(); | |
759 nm->add_offset_in_bytes( low10(0xbb) * wordSize ); | |
760 nm->print(); | |
761 | |
762 while (--idx) { | |
763 nm = nativeMovRegMemPatching_at( nm->next_instruction_address() ); | |
764 nm->print(); | |
765 for (idx1 = 0; idx1 < ARRAY_SIZE(offsets); idx1++) { | |
766 nm->set_offset( nm->is_immediate() ? low10(offsets[idx1]) : offsets[idx1] ); | |
767 assert(nm->offset() == (nm->is_immediate() ? low10(offsets[idx1]) : offsets[idx1]), | |
768 "check unit test"); | |
769 nm->print(); | |
770 } | |
771 nm->add_offset_in_bytes( low10(0xbb) * wordSize ); | |
772 nm->print(); | |
773 } | |
774 | |
775 VM_Version::revert(); | |
776 #endif // ASSERT | |
777 } | |
778 // End code for unit testing implementation of NativeMovRegMemPatching class | |
779 | |
780 | |
781 //-------------------------------------------------------------------------------- | |
782 | |
783 | |
784 void NativeJump::verify() { | |
785 NativeInstruction::verify(); | |
786 int i0 = long_at(sethi_offset); | |
787 int i1 = long_at(jmpl_offset); | |
788 assert((int)jmpl_offset == (int)NativeMovConstReg::add_offset, "sethi size ok"); | |
789 // verify the pattern "sethi %hi22(imm), treg ; jmpl treg, %lo10(imm), lreg" | |
790 Register rd = inv_rd(i0); | |
791 #ifndef _LP64 | |
792 if (!(is_op2(i0, Assembler::sethi_op2) && rd != G0 && | |
793 (is_op3(i1, Assembler::jmpl_op3, Assembler::arith_op) || | |
794 (TraceJumps && is_op3(i1, Assembler::add_op3, Assembler::arith_op))) && | |
795 inv_immed(i1) && (unsigned)get_simm13(i1) < (1 << 10) && | |
796 rd == inv_rs1(i1))) { | |
797 fatal("not a jump_to instruction"); | |
798 } | |
799 #else | |
800 // In LP64, the jump instruction location varies for non relocatable | |
801 // jumps, for example is could be sethi, xor, jmp instead of the | |
802 // 7 instructions for sethi. So let's check sethi only. | |
803 if (!is_op2(i0, Assembler::sethi_op2) && rd != G0 ) { | |
804 fatal("not a jump_to instruction"); | |
805 } | |
806 #endif | |
807 } | |
808 | |
809 | |
810 void NativeJump::print() { | |
811 tty->print_cr(INTPTR_FORMAT ": jmpl reg, " INTPTR_FORMAT, instruction_address(), jump_destination()); | |
812 } | |
813 | |
814 | |
815 // Code for unit testing implementation of NativeJump class | |
816 void NativeJump::test() { | |
817 #ifdef ASSERT | |
818 ResourceMark rm; | |
819 CodeBuffer cb("test", 100, 100); | |
820 MacroAssembler* a = new MacroAssembler(&cb); | |
821 NativeJump* nj; | |
822 uint idx; | |
823 int offsets[] = { | |
824 0x0, | |
825 0xffffffff, | |
826 0x7fffffff, | |
827 0x80000000, | |
828 4096, | |
829 4097, | |
830 0x20, | |
831 0x4000, | |
832 }; | |
833 | |
834 VM_Version::allow_all(); | |
835 | |
836 a->sethi(0x7fffbbbb, I3, true, RelocationHolder::none); | |
837 a->jmpl(I3, low10(0x7fffbbbb), G0, RelocationHolder::none); | |
838 a->delayed()->nop(); | |
839 a->sethi(0x7fffbbbb, I3, true, RelocationHolder::none); | |
840 a->jmpl(I3, low10(0x7fffbbbb), L3, RelocationHolder::none); | |
841 a->delayed()->nop(); | |
842 | |
843 nj = nativeJump_at( cb.code_begin() ); | |
844 nj->print(); | |
845 | |
846 nj = nativeJump_at( nj->next_instruction_address() ); | |
847 for (idx = 0; idx < ARRAY_SIZE(offsets); idx++) { | |
848 nj->set_jump_destination( nj->instruction_address() + offsets[idx] ); | |
849 assert(nj->jump_destination() == (nj->instruction_address() + offsets[idx]), "check unit test"); | |
850 nj->print(); | |
851 } | |
852 | |
853 VM_Version::revert(); | |
854 #endif // ASSERT | |
855 } | |
856 // End code for unit testing implementation of NativeJump class | |
857 | |
858 | |
859 void NativeJump::insert(address code_pos, address entry) { | |
860 Unimplemented(); | |
861 } | |
862 | |
863 // MT safe inserting of a jump over an unknown instruction sequence (used by nmethod::makeZombie) | |
864 // The problem: jump_to <dest> is a 3-word instruction (including its delay slot). | |
865 // Atomic write can be only with 1 word. | |
866 void NativeJump::patch_verified_entry(address entry, address verified_entry, address dest) { | |
867 // Here's one way to do it: Pre-allocate a three-word jump sequence somewhere | |
868 // in the header of the nmethod, within a short branch's span of the patch point. | |
869 // Set up the jump sequence using NativeJump::insert, and then use an annulled | |
870 // unconditional branch at the target site (an atomic 1-word update). | |
871 // Limitations: You can only patch nmethods, with any given nmethod patched at | |
872 // most once, and the patch must be in the nmethod's header. | |
873 // It's messy, but you can ask the CodeCache for the nmethod containing the | |
874 // target address. | |
875 | |
876 // %%%%% For now, do something MT-stupid: | |
877 ResourceMark rm; | |
878 int code_size = 1 * BytesPerInstWord; | |
879 CodeBuffer cb(verified_entry, code_size + 1); | |
880 MacroAssembler* a = new MacroAssembler(&cb); | |
881 if (VM_Version::v9_instructions_work()) { | |
882 a->ldsw(G0, 0, O7); // "ld" must agree with code in the signal handler | |
883 } else { | |
884 a->lduw(G0, 0, O7); // "ld" must agree with code in the signal handler | |
885 } | |
886 ICache::invalidate_range(verified_entry, code_size); | |
887 } | |
888 | |
889 | |
890 void NativeIllegalInstruction::insert(address code_pos) { | |
891 NativeIllegalInstruction* nii = (NativeIllegalInstruction*) nativeInstruction_at(code_pos); | |
892 nii->set_long_at(0, illegal_instruction()); | |
893 } | |
894 | |
895 static int illegal_instruction_bits = 0; | |
896 | |
897 int NativeInstruction::illegal_instruction() { | |
898 if (illegal_instruction_bits == 0) { | |
899 ResourceMark rm; | |
900 char buf[40]; | |
901 CodeBuffer cbuf((address)&buf[0], 20); | |
902 MacroAssembler* a = new MacroAssembler(&cbuf); | |
903 address ia = a->pc(); | |
904 a->trap(ST_RESERVED_FOR_USER_0 + 1); | |
905 int bits = *(int*)ia; | |
906 assert(is_op3(bits, Assembler::trap_op3, Assembler::arith_op), "bad instruction"); | |
907 illegal_instruction_bits = bits; | |
908 assert(illegal_instruction_bits != 0, "oops"); | |
909 } | |
910 return illegal_instruction_bits; | |
911 } | |
912 | |
913 static int ic_miss_trap_bits = 0; | |
914 | |
915 bool NativeInstruction::is_ic_miss_trap() { | |
916 if (ic_miss_trap_bits == 0) { | |
917 ResourceMark rm; | |
918 char buf[40]; | |
919 CodeBuffer cbuf((address)&buf[0], 20); | |
920 MacroAssembler* a = new MacroAssembler(&cbuf); | |
921 address ia = a->pc(); | |
922 a->trap(Assembler::notEqual, Assembler::ptr_cc, G0, ST_RESERVED_FOR_USER_0 + 2); | |
923 int bits = *(int*)ia; | |
924 assert(is_op3(bits, Assembler::trap_op3, Assembler::arith_op), "bad instruction"); | |
925 ic_miss_trap_bits = bits; | |
926 assert(ic_miss_trap_bits != 0, "oops"); | |
927 } | |
928 return long_at(0) == ic_miss_trap_bits; | |
929 } | |
930 | |
931 | |
932 bool NativeInstruction::is_illegal() { | |
933 if (illegal_instruction_bits == 0) { | |
934 return false; | |
935 } | |
936 return long_at(0) == illegal_instruction_bits; | |
937 } | |
938 | |
939 | |
940 void NativeGeneralJump::verify() { | |
941 assert(((NativeInstruction *)this)->is_jump() || | |
942 ((NativeInstruction *)this)->is_cond_jump(), "not a general jump instruction"); | |
943 } | |
944 | |
945 | |
946 void NativeGeneralJump::insert_unconditional(address code_pos, address entry) { | |
947 Assembler::Condition condition = Assembler::always; | |
948 int x = Assembler::op2(Assembler::br_op2) | Assembler::annul(false) | | |
949 Assembler::cond(condition) | Assembler::wdisp((intptr_t)entry, (intptr_t)code_pos, 22); | |
950 NativeGeneralJump* ni = (NativeGeneralJump*) nativeInstruction_at(code_pos); | |
951 ni->set_long_at(0, x); | |
952 } | |
953 | |
954 | |
955 // MT-safe patching of a jmp instruction (and following word). | |
956 // First patches the second word, and then atomicly replaces | |
957 // the first word with the first new instruction word. | |
958 // Other processors might briefly see the old first word | |
959 // followed by the new second word. This is OK if the old | |
960 // second word is harmless, and the new second word may be | |
961 // harmlessly executed in the delay slot of the call. | |
962 void NativeGeneralJump::replace_mt_safe(address instr_addr, address code_buffer) { | |
963 assert(Patching_lock->is_locked() || | |
964 SafepointSynchronize::is_at_safepoint(), "concurrent code patching"); | |
965 assert (instr_addr != NULL, "illegal address for code patching"); | |
966 NativeGeneralJump* h_jump = nativeGeneralJump_at (instr_addr); // checking that it is a call | |
967 assert(NativeGeneralJump::instruction_size == 8, "wrong instruction size; must be 8"); | |
968 int i0 = ((int*)code_buffer)[0]; | |
969 int i1 = ((int*)code_buffer)[1]; | |
970 int* contention_addr = (int*) h_jump->addr_at(1*BytesPerInstWord); | |
971 assert(inv_op(*contention_addr) == Assembler::arith_op || | |
972 *contention_addr == nop_instruction() || !VM_Version::v9_instructions_work(), | |
973 "must not interfere with original call"); | |
974 // The set_long_at calls do the ICacheInvalidate so we just need to do them in reverse order | |
975 h_jump->set_long_at(1*BytesPerInstWord, i1); | |
976 h_jump->set_long_at(0*BytesPerInstWord, i0); | |
977 // NOTE: It is possible that another thread T will execute | |
978 // only the second patched word. | |
979 // In other words, since the original instruction is this | |
980 // jmp patching_stub; nop (NativeGeneralJump) | |
981 // and the new sequence from the buffer is this: | |
982 // sethi %hi(K), %r; add %r, %lo(K), %r (NativeMovConstReg) | |
983 // what T will execute is this: | |
984 // jmp patching_stub; add %r, %lo(K), %r | |
985 // thereby putting garbage into %r before calling the patching stub. | |
986 // This is OK, because the patching stub ignores the value of %r. | |
987 | |
988 // Make sure the first-patched instruction, which may co-exist | |
989 // briefly with the call, will do something harmless. | |
990 assert(inv_op(*contention_addr) == Assembler::arith_op || | |
991 *contention_addr == nop_instruction() || !VM_Version::v9_instructions_work(), | |
992 "must not interfere with original call"); | |
993 } |