296 assert(a_byte == *start++, "should be the same code");
297 }
298 #endif
299 } else if (_id == load_mirror_id) {
300 // produce a copy of the load mirror instruction for use by the being
301 // initialized case
302 #ifdef ASSERT
303 address start = __ pc();
304 #endif
305 jobject o = NULL;
306 __ movoop(_obj, o);
307 #ifdef ASSERT
308 for (int i = 0; i < _bytes_to_copy; i++) {
309 address ptr = (address)(_pc_start + i);
310 int a_byte = (*ptr) & 0xFF;
311 assert(a_byte == *start++, "should be the same code");
312 }
313 #endif
314 } else {
315 // make a copy the code which is going to be patched.
316 for ( int i = 0; i < _bytes_to_copy; i++) {
317 address ptr = (address)(_pc_start + i);
318 int a_byte = (*ptr) & 0xFF;
319 __ a_byte (a_byte);
320 *ptr = 0x90; // make the site look like a nop
321 }
322 }
323
324 address end_of_patch = __ pc();
325 int bytes_to_skip = 0;
326 if (_id == load_mirror_id) {
327 int offset = __ offset();
328 if (CommentedAssembly) {
329 __ block_comment(" being_initialized check");
330 }
331 assert(_obj != noreg, "must be a valid register");
332 Register tmp = rax;
333 Register tmp2 = rbx;
334 __ push(tmp);
335 __ push(tmp2);
336 // Load without verification to keep code size small. We need it because
337 // begin_initialized_entry_offset has to fit in a byte. Also, we know it's not null.
338 __ movptr(tmp2, Address(_obj, java_lang_Class::klass_offset_in_bytes()));
339 __ get_thread(tmp);
346 // copied back into place so we need to jump back into the main
347 // code of the nmethod to continue execution.
348 __ jmp(_patch_site_continuation);
349
350 // make sure this extra code gets skipped
351 bytes_to_skip += __ offset() - offset;
352 }
353 if (CommentedAssembly) {
354 __ block_comment("patch data encoded as movl");
355 }
356 // Now emit the patch record telling the runtime how to find the
357 // pieces of the patch. We only need 3 bytes but for readability of
358 // the disassembly we make the data look like a movl reg, imm32,
359 // which requires 5 bytes
360 int sizeof_patch_record = 5;
361 bytes_to_skip += sizeof_patch_record;
362
363 // emit the offsets needed to find the code to patch
364 int being_initialized_entry_offset = __ pc() - being_initialized_entry + sizeof_patch_record;
365
366 __ a_byte(0xB8);
367 __ a_byte(0);
368 __ a_byte(being_initialized_entry_offset);
369 __ a_byte(bytes_to_skip);
370 __ a_byte(_bytes_to_copy);
371 address patch_info_pc = __ pc();
372 assert(patch_info_pc - end_of_patch == bytes_to_skip, "incorrect patch info");
373
374 address entry = __ pc();
375 NativeGeneralJump::insert_unconditional((address)_pc_start, entry);
376 address target = NULL;
377 relocInfo::relocType reloc_type = relocInfo::none;
378 switch (_id) {
379 case access_field_id: target = Runtime1::entry_for(Runtime1::access_field_patching_id); break;
380 case load_klass_id: target = Runtime1::entry_for(Runtime1::load_klass_patching_id); reloc_type = relocInfo::metadata_type; break;
381 case load_mirror_id: target = Runtime1::entry_for(Runtime1::load_mirror_patching_id); reloc_type = relocInfo::oop_type; break;
382 default: ShouldNotReachHere();
383 }
384 __ bind(call_patch);
385
386 if (CommentedAssembly) {
387 __ block_comment("patch entry point");
388 }
389 __ call(RuntimeAddress(target));
390 assert(_patch_info_offset == (patch_info_pc - __ pc()), "must not change");
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296 assert(a_byte == *start++, "should be the same code");
297 }
298 #endif
299 } else if (_id == load_mirror_id) {
300 // produce a copy of the load mirror instruction for use by the being
301 // initialized case
302 #ifdef ASSERT
303 address start = __ pc();
304 #endif
305 jobject o = NULL;
306 __ movoop(_obj, o);
307 #ifdef ASSERT
308 for (int i = 0; i < _bytes_to_copy; i++) {
309 address ptr = (address)(_pc_start + i);
310 int a_byte = (*ptr) & 0xFF;
311 assert(a_byte == *start++, "should be the same code");
312 }
313 #endif
314 } else {
315 // make a copy the code which is going to be patched.
316 for (int i = 0; i < _bytes_to_copy; i++) {
317 address ptr = (address)(_pc_start + i);
318 int a_byte = (*ptr) & 0xFF;
319 __ emit_int8(a_byte);
320 *ptr = 0x90; // make the site look like a nop
321 }
322 }
323
324 address end_of_patch = __ pc();
325 int bytes_to_skip = 0;
326 if (_id == load_mirror_id) {
327 int offset = __ offset();
328 if (CommentedAssembly) {
329 __ block_comment(" being_initialized check");
330 }
331 assert(_obj != noreg, "must be a valid register");
332 Register tmp = rax;
333 Register tmp2 = rbx;
334 __ push(tmp);
335 __ push(tmp2);
336 // Load without verification to keep code size small. We need it because
337 // begin_initialized_entry_offset has to fit in a byte. Also, we know it's not null.
338 __ movptr(tmp2, Address(_obj, java_lang_Class::klass_offset_in_bytes()));
339 __ get_thread(tmp);
346 // copied back into place so we need to jump back into the main
347 // code of the nmethod to continue execution.
348 __ jmp(_patch_site_continuation);
349
350 // make sure this extra code gets skipped
351 bytes_to_skip += __ offset() - offset;
352 }
353 if (CommentedAssembly) {
354 __ block_comment("patch data encoded as movl");
355 }
356 // Now emit the patch record telling the runtime how to find the
357 // pieces of the patch. We only need 3 bytes but for readability of
358 // the disassembly we make the data look like a movl reg, imm32,
359 // which requires 5 bytes
360 int sizeof_patch_record = 5;
361 bytes_to_skip += sizeof_patch_record;
362
363 // emit the offsets needed to find the code to patch
364 int being_initialized_entry_offset = __ pc() - being_initialized_entry + sizeof_patch_record;
365
366 __ emit_int8((unsigned char)0xB8);
367 __ emit_int8(0);
368 __ emit_int8(being_initialized_entry_offset);
369 __ emit_int8(bytes_to_skip);
370 __ emit_int8(_bytes_to_copy);
371 address patch_info_pc = __ pc();
372 assert(patch_info_pc - end_of_patch == bytes_to_skip, "incorrect patch info");
373
374 address entry = __ pc();
375 NativeGeneralJump::insert_unconditional((address)_pc_start, entry);
376 address target = NULL;
377 relocInfo::relocType reloc_type = relocInfo::none;
378 switch (_id) {
379 case access_field_id: target = Runtime1::entry_for(Runtime1::access_field_patching_id); break;
380 case load_klass_id: target = Runtime1::entry_for(Runtime1::load_klass_patching_id); reloc_type = relocInfo::metadata_type; break;
381 case load_mirror_id: target = Runtime1::entry_for(Runtime1::load_mirror_patching_id); reloc_type = relocInfo::oop_type; break;
382 default: ShouldNotReachHere();
383 }
384 __ bind(call_patch);
385
386 if (CommentedAssembly) {
387 __ block_comment("patch entry point");
388 }
389 __ call(RuntimeAddress(target));
390 assert(_patch_info_offset == (patch_info_pc - __ pc()), "must not change");
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