1 /*
   2  * Copyright 1999-2007 Sun Microsystems, Inc.  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 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/_stubGenerator_x86_32.cpp.incl"
  27 
  28 // Declaration and definition of StubGenerator (no .hpp file).
  29 // For a more detailed description of the stub routine structure
  30 // see the comment in stubRoutines.hpp
  31 
  32 #define __ _masm->
  33 #define a__ ((Assembler*)_masm)->
  34 
  35 #ifdef PRODUCT
  36 #define BLOCK_COMMENT(str) /* nothing */
  37 #else
  38 #define BLOCK_COMMENT(str) __ block_comment(str)
  39 #endif
  40 
  41 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
  42 
  43 const int MXCSR_MASK  = 0xFFC0;  // Mask out any pending exceptions
  44 const int FPU_CNTRL_WRD_MASK = 0xFFFF;
  45 
  46 // -------------------------------------------------------------------------------------------------------------------------
  47 // Stub Code definitions
  48 
  49 static address handle_unsafe_access() {
  50   JavaThread* thread = JavaThread::current();
  51   address pc  = thread->saved_exception_pc();
  52   // pc is the instruction which we must emulate
  53   // doing a no-op is fine:  return garbage from the load
  54   // therefore, compute npc
  55   address npc = Assembler::locate_next_instruction(pc);
  56 
  57   // request an async exception
  58   thread->set_pending_unsafe_access_error();
  59 
  60   // return address of next instruction to execute
  61   return npc;
  62 }
  63 
  64 class StubGenerator: public StubCodeGenerator {
  65  private:
  66 
  67 #ifdef PRODUCT
  68 #define inc_counter_np(counter) (0)
  69 #else
  70   void inc_counter_np_(int& counter) {
  71     __ incrementl(ExternalAddress((address)&counter));
  72   }
  73 #define inc_counter_np(counter) \
  74   BLOCK_COMMENT("inc_counter " #counter); \
  75   inc_counter_np_(counter);
  76 #endif //PRODUCT
  77 
  78   void inc_copy_counter_np(BasicType t) {
  79 #ifndef PRODUCT
  80     switch (t) {
  81     case T_BYTE:    inc_counter_np(SharedRuntime::_jbyte_array_copy_ctr); return;
  82     case T_SHORT:   inc_counter_np(SharedRuntime::_jshort_array_copy_ctr); return;
  83     case T_INT:     inc_counter_np(SharedRuntime::_jint_array_copy_ctr); return;
  84     case T_LONG:    inc_counter_np(SharedRuntime::_jlong_array_copy_ctr); return;
  85     case T_OBJECT:  inc_counter_np(SharedRuntime::_oop_array_copy_ctr); return;
  86     }
  87     ShouldNotReachHere();
  88 #endif //PRODUCT
  89   }
  90 
  91   //------------------------------------------------------------------------------------------------------------------------
  92   // Call stubs are used to call Java from C
  93   //
  94   //    [ return_from_Java     ] <--- rsp
  95   //    [ argument word n      ]
  96   //      ...
  97   // -N [ argument word 1      ]
  98   // -7 [ Possible padding for stack alignment ]
  99   // -6 [ Possible padding for stack alignment ]
 100   // -5 [ Possible padding for stack alignment ]
 101   // -4 [ mxcsr save           ] <--- rsp_after_call
 102   // -3 [ saved rbx,            ]
 103   // -2 [ saved rsi            ]
 104   // -1 [ saved rdi            ]
 105   //  0 [ saved rbp,            ] <--- rbp,
 106   //  1 [ return address       ]
 107   //  2 [ ptr. to call wrapper ]
 108   //  3 [ result               ]
 109   //  4 [ result_type          ]
 110   //  5 [ method               ]
 111   //  6 [ entry_point          ]
 112   //  7 [ parameters           ]
 113   //  8 [ parameter_size       ]
 114   //  9 [ thread               ]
 115 
 116 
 117   address generate_call_stub(address& return_address) {
 118     StubCodeMark mark(this, "StubRoutines", "call_stub");
 119     address start = __ pc();
 120 
 121     // stub code parameters / addresses
 122     assert(frame::entry_frame_call_wrapper_offset == 2, "adjust this code");
 123     bool  sse_save = false;
 124     const Address rsp_after_call(rbp, -4 * wordSize); // same as in generate_catch_exception()!
 125     const int     locals_count_in_bytes  (4*wordSize);
 126     const Address mxcsr_save    (rbp, -4 * wordSize);
 127     const Address saved_rbx     (rbp, -3 * wordSize);
 128     const Address saved_rsi     (rbp, -2 * wordSize);
 129     const Address saved_rdi     (rbp, -1 * wordSize);
 130     const Address result        (rbp,  3 * wordSize);
 131     const Address result_type   (rbp,  4 * wordSize);
 132     const Address method        (rbp,  5 * wordSize);
 133     const Address entry_point   (rbp,  6 * wordSize);
 134     const Address parameters    (rbp,  7 * wordSize);
 135     const Address parameter_size(rbp,  8 * wordSize);
 136     const Address thread        (rbp,  9 * wordSize); // same as in generate_catch_exception()!
 137     sse_save =  UseSSE > 0;
 138 
 139     // stub code
 140     __ enter();
 141     __ movptr(rcx, parameter_size);              // parameter counter
 142     __ shlptr(rcx, Interpreter::logStackElementSize()); // convert parameter count to bytes
 143     __ addptr(rcx, locals_count_in_bytes);       // reserve space for register saves
 144     __ subptr(rsp, rcx);
 145     __ andptr(rsp, -(StackAlignmentInBytes));    // Align stack
 146 
 147     // save rdi, rsi, & rbx, according to C calling conventions
 148     __ movptr(saved_rdi, rdi);
 149     __ movptr(saved_rsi, rsi);
 150     __ movptr(saved_rbx, rbx);
 151     // save and initialize %mxcsr
 152     if (sse_save) {
 153       Label skip_ldmx;
 154       __ stmxcsr(mxcsr_save);
 155       __ movl(rax, mxcsr_save);
 156       __ andl(rax, MXCSR_MASK);    // Only check control and mask bits
 157       ExternalAddress mxcsr_std(StubRoutines::addr_mxcsr_std());
 158       __ cmp32(rax, mxcsr_std);
 159       __ jcc(Assembler::equal, skip_ldmx);
 160       __ ldmxcsr(mxcsr_std);
 161       __ bind(skip_ldmx);
 162     }
 163 
 164     // make sure the control word is correct.
 165     __ fldcw(ExternalAddress(StubRoutines::addr_fpu_cntrl_wrd_std()));
 166 
 167 #ifdef ASSERT
 168     // make sure we have no pending exceptions
 169     { Label L;
 170       __ movptr(rcx, thread);
 171       __ cmpptr(Address(rcx, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
 172       __ jcc(Assembler::equal, L);
 173       __ stop("StubRoutines::call_stub: entered with pending exception");
 174       __ bind(L);
 175     }
 176 #endif
 177 
 178     // pass parameters if any
 179     BLOCK_COMMENT("pass parameters if any");
 180     Label parameters_done;
 181     __ movl(rcx, parameter_size);  // parameter counter
 182     __ testl(rcx, rcx);
 183     __ jcc(Assembler::zero, parameters_done);
 184 
 185     // parameter passing loop
 186 
 187     Label loop;
 188     // Copy Java parameters in reverse order (receiver last)
 189     // Note that the argument order is inverted in the process
 190     // source is rdx[rcx: N-1..0]
 191     // dest   is rsp[rbx: 0..N-1]
 192 
 193     __ movptr(rdx, parameters);          // parameter pointer
 194     __ xorptr(rbx, rbx);
 195 
 196     __ BIND(loop);
 197     if (TaggedStackInterpreter) {
 198       __ movptr(rax, Address(rdx, rcx, Interpreter::stackElementScale(),
 199                       -2*wordSize));                          // get tag
 200       __ movptr(Address(rsp, rbx, Interpreter::stackElementScale(),
 201                       Interpreter::expr_tag_offset_in_bytes(0)), rax);     // store tag
 202     }
 203 
 204     // get parameter
 205     __ movptr(rax, Address(rdx, rcx, Interpreter::stackElementScale(), -wordSize));
 206     __ movptr(Address(rsp, rbx, Interpreter::stackElementScale(),
 207                     Interpreter::expr_offset_in_bytes(0)), rax);          // store parameter
 208     __ increment(rbx);
 209     __ decrement(rcx);
 210     __ jcc(Assembler::notZero, loop);
 211 
 212     // call Java function
 213     __ BIND(parameters_done);
 214     __ movptr(rbx, method);           // get methodOop
 215     __ movptr(rax, entry_point);      // get entry_point
 216     __ mov(rsi, rsp);                 // set sender sp
 217     BLOCK_COMMENT("call Java function");
 218     __ call(rax);
 219 
 220     BLOCK_COMMENT("call_stub_return_address:");
 221     return_address = __ pc();
 222 
 223     Label common_return;
 224 
 225     __ BIND(common_return);
 226 
 227     // store result depending on type
 228     // (everything that is not T_LONG, T_FLOAT or T_DOUBLE is treated as T_INT)
 229     __ movptr(rdi, result);
 230     Label is_long, is_float, is_double, exit;
 231     __ movl(rsi, result_type);
 232     __ cmpl(rsi, T_LONG);
 233     __ jcc(Assembler::equal, is_long);
 234     __ cmpl(rsi, T_FLOAT);
 235     __ jcc(Assembler::equal, is_float);
 236     __ cmpl(rsi, T_DOUBLE);
 237     __ jcc(Assembler::equal, is_double);
 238 
 239     // handle T_INT case
 240     __ movl(Address(rdi, 0), rax);
 241     __ BIND(exit);
 242 
 243     // check that FPU stack is empty
 244     __ verify_FPU(0, "generate_call_stub");
 245 
 246     // pop parameters
 247     __ lea(rsp, rsp_after_call);
 248 
 249     // restore %mxcsr
 250     if (sse_save) {
 251       __ ldmxcsr(mxcsr_save);
 252     }
 253 
 254     // restore rdi, rsi and rbx,
 255     __ movptr(rbx, saved_rbx);
 256     __ movptr(rsi, saved_rsi);
 257     __ movptr(rdi, saved_rdi);
 258     __ addptr(rsp, 4*wordSize);
 259 
 260     // return
 261     __ pop(rbp);
 262     __ ret(0);
 263 
 264     // handle return types different from T_INT
 265     __ BIND(is_long);
 266     __ movl(Address(rdi, 0 * wordSize), rax);
 267     __ movl(Address(rdi, 1 * wordSize), rdx);
 268     __ jmp(exit);
 269 
 270     __ BIND(is_float);
 271     // interpreter uses xmm0 for return values
 272     if (UseSSE >= 1) {
 273       __ movflt(Address(rdi, 0), xmm0);
 274     } else {
 275       __ fstp_s(Address(rdi, 0));
 276     }
 277     __ jmp(exit);
 278 
 279     __ BIND(is_double);
 280     // interpreter uses xmm0 for return values
 281     if (UseSSE >= 2) {
 282       __ movdbl(Address(rdi, 0), xmm0);
 283     } else {
 284       __ fstp_d(Address(rdi, 0));
 285     }
 286     __ jmp(exit);
 287 
 288     // If we call compiled code directly from the call stub we will
 289     // need to adjust the return back to the call stub to a specialized
 290     // piece of code that can handle compiled results and cleaning the fpu
 291     // stack. compiled code will be set to return here instead of the
 292     // return above that handles interpreter returns.
 293 
 294     BLOCK_COMMENT("call_stub_compiled_return:");
 295     StubRoutines::x86::set_call_stub_compiled_return( __ pc());
 296 
 297 #ifdef COMPILER2
 298     if (UseSSE >= 2) {
 299       __ verify_FPU(0, "call_stub_compiled_return");
 300     } else {
 301       for (int i = 1; i < 8; i++) {
 302         __ ffree(i);
 303       }
 304 
 305       // UseSSE <= 1 so double result should be left on TOS
 306       __ movl(rsi, result_type);
 307       __ cmpl(rsi, T_DOUBLE);
 308       __ jcc(Assembler::equal, common_return);
 309       if (UseSSE == 0) {
 310         // UseSSE == 0 so float result should be left on TOS
 311         __ cmpl(rsi, T_FLOAT);
 312         __ jcc(Assembler::equal, common_return);
 313       }
 314       __ ffree(0);
 315     }
 316 #endif /* COMPILER2 */
 317     __ jmp(common_return);
 318 
 319     return start;
 320   }
 321 
 322 
 323   //------------------------------------------------------------------------------------------------------------------------
 324   // Return point for a Java call if there's an exception thrown in Java code.
 325   // The exception is caught and transformed into a pending exception stored in
 326   // JavaThread that can be tested from within the VM.
 327   //
 328   // Note: Usually the parameters are removed by the callee. In case of an exception
 329   //       crossing an activation frame boundary, that is not the case if the callee
 330   //       is compiled code => need to setup the rsp.
 331   //
 332   // rax,: exception oop
 333 
 334   address generate_catch_exception() {
 335     StubCodeMark mark(this, "StubRoutines", "catch_exception");
 336     const Address rsp_after_call(rbp, -4 * wordSize); // same as in generate_call_stub()!
 337     const Address thread        (rbp,  9 * wordSize); // same as in generate_call_stub()!
 338     address start = __ pc();
 339 
 340     // get thread directly
 341     __ movptr(rcx, thread);
 342 #ifdef ASSERT
 343     // verify that threads correspond
 344     { Label L;
 345       __ get_thread(rbx);
 346       __ cmpptr(rbx, rcx);
 347       __ jcc(Assembler::equal, L);
 348       __ stop("StubRoutines::catch_exception: threads must correspond");
 349       __ bind(L);
 350     }
 351 #endif
 352     // set pending exception
 353     __ verify_oop(rax);
 354     __ movptr(Address(rcx, Thread::pending_exception_offset()), rax          );
 355     __ lea(Address(rcx, Thread::exception_file_offset   ()),
 356            ExternalAddress((address)__FILE__));
 357     __ movl(Address(rcx, Thread::exception_line_offset   ()), __LINE__ );
 358     // complete return to VM
 359     assert(StubRoutines::_call_stub_return_address != NULL, "_call_stub_return_address must have been generated before");
 360     __ jump(RuntimeAddress(StubRoutines::_call_stub_return_address));
 361 
 362     return start;
 363   }
 364 
 365 
 366   //------------------------------------------------------------------------------------------------------------------------
 367   // Continuation point for runtime calls returning with a pending exception.
 368   // The pending exception check happened in the runtime or native call stub.
 369   // The pending exception in Thread is converted into a Java-level exception.
 370   //
 371   // Contract with Java-level exception handlers:
 372   // rax,: exception
 373   // rdx: throwing pc
 374   //
 375   // NOTE: At entry of this stub, exception-pc must be on stack !!
 376 
 377   address generate_forward_exception() {
 378     StubCodeMark mark(this, "StubRoutines", "forward exception");
 379     address start = __ pc();
 380 
 381     // Upon entry, the sp points to the return address returning into Java
 382     // (interpreted or compiled) code; i.e., the return address becomes the
 383     // throwing pc.
 384     //
 385     // Arguments pushed before the runtime call are still on the stack but
 386     // the exception handler will reset the stack pointer -> ignore them.
 387     // A potential result in registers can be ignored as well.
 388 
 389 #ifdef ASSERT
 390     // make sure this code is only executed if there is a pending exception
 391     { Label L;
 392       __ get_thread(rcx);
 393       __ cmpptr(Address(rcx, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
 394       __ jcc(Assembler::notEqual, L);
 395       __ stop("StubRoutines::forward exception: no pending exception (1)");
 396       __ bind(L);
 397     }
 398 #endif
 399 
 400     // compute exception handler into rbx,
 401     __ movptr(rax, Address(rsp, 0));
 402     BLOCK_COMMENT("call exception_handler_for_return_address");
 403     __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::exception_handler_for_return_address), rax);
 404     __ mov(rbx, rax);
 405 
 406     // setup rax, & rdx, remove return address & clear pending exception
 407     __ get_thread(rcx);
 408     __ pop(rdx);
 409     __ movptr(rax, Address(rcx, Thread::pending_exception_offset()));
 410     __ movptr(Address(rcx, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
 411 
 412 #ifdef ASSERT
 413     // make sure exception is set
 414     { Label L;
 415       __ testptr(rax, rax);
 416       __ jcc(Assembler::notEqual, L);
 417       __ stop("StubRoutines::forward exception: no pending exception (2)");
 418       __ bind(L);
 419     }
 420 #endif
 421 
 422     // continue at exception handler (return address removed)
 423     // rax,: exception
 424     // rbx,: exception handler
 425     // rdx: throwing pc
 426     __ verify_oop(rax);
 427     __ jmp(rbx);
 428 
 429     return start;
 430   }
 431 
 432 
 433   //----------------------------------------------------------------------------------------------------
 434   // Support for jint Atomic::xchg(jint exchange_value, volatile jint* dest)
 435   //
 436   // xchg exists as far back as 8086, lock needed for MP only
 437   // Stack layout immediately after call:
 438   //
 439   // 0 [ret addr ] <--- rsp
 440   // 1 [  ex     ]
 441   // 2 [  dest   ]
 442   //
 443   // Result:   *dest <- ex, return (old *dest)
 444   //
 445   // Note: win32 does not currently use this code
 446 
 447   address generate_atomic_xchg() {
 448     StubCodeMark mark(this, "StubRoutines", "atomic_xchg");
 449     address start = __ pc();
 450 
 451     __ push(rdx);
 452     Address exchange(rsp, 2 * wordSize);
 453     Address dest_addr(rsp, 3 * wordSize);
 454     __ movl(rax, exchange);
 455     __ movptr(rdx, dest_addr);
 456     __ xchgl(rax, Address(rdx, 0));
 457     __ pop(rdx);
 458     __ ret(0);
 459 
 460     return start;
 461   }
 462 
 463   //----------------------------------------------------------------------------------------------------
 464   // Support for void verify_mxcsr()
 465   //
 466   // This routine is used with -Xcheck:jni to verify that native
 467   // JNI code does not return to Java code without restoring the
 468   // MXCSR register to our expected state.
 469 
 470 
 471   address generate_verify_mxcsr() {
 472     StubCodeMark mark(this, "StubRoutines", "verify_mxcsr");
 473     address start = __ pc();
 474 
 475     const Address mxcsr_save(rsp, 0);
 476 
 477     if (CheckJNICalls && UseSSE > 0 ) {
 478       Label ok_ret;
 479       ExternalAddress mxcsr_std(StubRoutines::addr_mxcsr_std());
 480       __ push(rax);
 481       __ subptr(rsp, wordSize);      // allocate a temp location
 482       __ stmxcsr(mxcsr_save);
 483       __ movl(rax, mxcsr_save);
 484       __ andl(rax, MXCSR_MASK);
 485       __ cmp32(rax, mxcsr_std);
 486       __ jcc(Assembler::equal, ok_ret);
 487 
 488       __ warn("MXCSR changed by native JNI code.");
 489 
 490       __ ldmxcsr(mxcsr_std);
 491 
 492       __ bind(ok_ret);
 493       __ addptr(rsp, wordSize);
 494       __ pop(rax);
 495     }
 496 
 497     __ ret(0);
 498 
 499     return start;
 500   }
 501 
 502 
 503   //---------------------------------------------------------------------------
 504   // Support for void verify_fpu_cntrl_wrd()
 505   //
 506   // This routine is used with -Xcheck:jni to verify that native
 507   // JNI code does not return to Java code without restoring the
 508   // FP control word to our expected state.
 509 
 510   address generate_verify_fpu_cntrl_wrd() {
 511     StubCodeMark mark(this, "StubRoutines", "verify_spcw");
 512     address start = __ pc();
 513 
 514     const Address fpu_cntrl_wrd_save(rsp, 0);
 515 
 516     if (CheckJNICalls) {
 517       Label ok_ret;
 518       __ push(rax);
 519       __ subptr(rsp, wordSize);      // allocate a temp location
 520       __ fnstcw(fpu_cntrl_wrd_save);
 521       __ movl(rax, fpu_cntrl_wrd_save);
 522       __ andl(rax, FPU_CNTRL_WRD_MASK);
 523       ExternalAddress fpu_std(StubRoutines::addr_fpu_cntrl_wrd_std());
 524       __ cmp32(rax, fpu_std);
 525       __ jcc(Assembler::equal, ok_ret);
 526 
 527       __ warn("Floating point control word changed by native JNI code.");
 528 
 529       __ fldcw(fpu_std);
 530 
 531       __ bind(ok_ret);
 532       __ addptr(rsp, wordSize);
 533       __ pop(rax);
 534     }
 535 
 536     __ ret(0);
 537 
 538     return start;
 539   }
 540 
 541   //---------------------------------------------------------------------------
 542   // Wrapper for slow-case handling of double-to-integer conversion
 543   // d2i or f2i fast case failed either because it is nan or because
 544   // of under/overflow.
 545   // Input:  FPU TOS: float value
 546   // Output: rax, (rdx): integer (long) result
 547 
 548   address generate_d2i_wrapper(BasicType t, address fcn) {
 549     StubCodeMark mark(this, "StubRoutines", "d2i_wrapper");
 550     address start = __ pc();
 551 
 552   // Capture info about frame layout
 553   enum layout { FPUState_off         = 0,
 554                 rbp_off              = FPUStateSizeInWords,
 555                 rdi_off,
 556                 rsi_off,
 557                 rcx_off,
 558                 rbx_off,
 559                 saved_argument_off,
 560                 saved_argument_off2, // 2nd half of double
 561                 framesize
 562   };
 563 
 564   assert(FPUStateSizeInWords == 27, "update stack layout");
 565 
 566     // Save outgoing argument to stack across push_FPU_state()
 567     __ subptr(rsp, wordSize * 2);
 568     __ fstp_d(Address(rsp, 0));
 569 
 570     // Save CPU & FPU state
 571     __ push(rbx);
 572     __ push(rcx);
 573     __ push(rsi);
 574     __ push(rdi);
 575     __ push(rbp);
 576     __ push_FPU_state();
 577 
 578     // push_FPU_state() resets the FP top of stack
 579     // Load original double into FP top of stack
 580     __ fld_d(Address(rsp, saved_argument_off * wordSize));
 581     // Store double into stack as outgoing argument
 582     __ subptr(rsp, wordSize*2);
 583     __ fst_d(Address(rsp, 0));
 584 
 585     // Prepare FPU for doing math in C-land
 586     __ empty_FPU_stack();
 587     // Call the C code to massage the double.  Result in EAX
 588     if (t == T_INT)
 589       { BLOCK_COMMENT("SharedRuntime::d2i"); }
 590     else if (t == T_LONG)
 591       { BLOCK_COMMENT("SharedRuntime::d2l"); }
 592     __ call_VM_leaf( fcn, 2 );
 593 
 594     // Restore CPU & FPU state
 595     __ pop_FPU_state();
 596     __ pop(rbp);
 597     __ pop(rdi);
 598     __ pop(rsi);
 599     __ pop(rcx);
 600     __ pop(rbx);
 601     __ addptr(rsp, wordSize * 2);
 602 
 603     __ ret(0);
 604 
 605     return start;
 606   }
 607 
 608 
 609   //---------------------------------------------------------------------------
 610   // The following routine generates a subroutine to throw an asynchronous
 611   // UnknownError when an unsafe access gets a fault that could not be
 612   // reasonably prevented by the programmer.  (Example: SIGBUS/OBJERR.)
 613   address generate_handler_for_unsafe_access() {
 614     StubCodeMark mark(this, "StubRoutines", "handler_for_unsafe_access");
 615     address start = __ pc();
 616 
 617     __ push(0);                       // hole for return address-to-be
 618     __ pusha();                       // push registers
 619     Address next_pc(rsp, RegisterImpl::number_of_registers * BytesPerWord);
 620     BLOCK_COMMENT("call handle_unsafe_access");
 621     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, handle_unsafe_access)));
 622     __ movptr(next_pc, rax);          // stuff next address
 623     __ popa();
 624     __ ret(0);                        // jump to next address
 625 
 626     return start;
 627   }
 628 
 629 
 630   //----------------------------------------------------------------------------------------------------
 631   // Non-destructive plausibility checks for oops
 632 
 633   address generate_verify_oop() {
 634     StubCodeMark mark(this, "StubRoutines", "verify_oop");
 635     address start = __ pc();
 636 
 637     // Incoming arguments on stack after saving rax,:
 638     //
 639     // [tos    ]: saved rdx
 640     // [tos + 1]: saved EFLAGS
 641     // [tos + 2]: return address
 642     // [tos + 3]: char* error message
 643     // [tos + 4]: oop   object to verify
 644     // [tos + 5]: saved rax, - saved by caller and bashed
 645 
 646     Label exit, error;
 647     __ pushf();
 648     __ incrementl(ExternalAddress((address) StubRoutines::verify_oop_count_addr()));
 649     __ push(rdx);                                // save rdx
 650     // make sure object is 'reasonable'
 651     __ movptr(rax, Address(rsp, 4 * wordSize));    // get object
 652     __ testptr(rax, rax);
 653     __ jcc(Assembler::zero, exit);               // if obj is NULL it is ok
 654 
 655     // Check if the oop is in the right area of memory
 656     const int oop_mask = Universe::verify_oop_mask();
 657     const int oop_bits = Universe::verify_oop_bits();
 658     __ mov(rdx, rax);
 659     __ andptr(rdx, oop_mask);
 660     __ cmpptr(rdx, oop_bits);
 661     __ jcc(Assembler::notZero, error);
 662 
 663     // make sure klass is 'reasonable'
 664     __ movptr(rax, Address(rax, oopDesc::klass_offset_in_bytes())); // get klass
 665     __ testptr(rax, rax);
 666     __ jcc(Assembler::zero, error);              // if klass is NULL it is broken
 667 
 668     // Check if the klass is in the right area of memory
 669     const int klass_mask = Universe::verify_klass_mask();
 670     const int klass_bits = Universe::verify_klass_bits();
 671     __ mov(rdx, rax);
 672     __ andptr(rdx, klass_mask);
 673     __ cmpptr(rdx, klass_bits);
 674     __ jcc(Assembler::notZero, error);
 675 
 676     // make sure klass' klass is 'reasonable'
 677     __ movptr(rax, Address(rax, oopDesc::klass_offset_in_bytes())); // get klass' klass
 678     __ testptr(rax, rax);
 679     __ jcc(Assembler::zero, error);              // if klass' klass is NULL it is broken
 680 
 681     __ mov(rdx, rax);
 682     __ andptr(rdx, klass_mask);
 683     __ cmpptr(rdx, klass_bits);
 684     __ jcc(Assembler::notZero, error);           // if klass not in right area
 685                                                  // of memory it is broken too.
 686 
 687     // return if everything seems ok
 688     __ bind(exit);
 689     __ movptr(rax, Address(rsp, 5 * wordSize));  // get saved rax, back
 690     __ pop(rdx);                                 // restore rdx
 691     __ popf();                                   // restore EFLAGS
 692     __ ret(3 * wordSize);                        // pop arguments
 693 
 694     // handle errors
 695     __ bind(error);
 696     __ movptr(rax, Address(rsp, 5 * wordSize));  // get saved rax, back
 697     __ pop(rdx);                                 // get saved rdx back
 698     __ popf();                                   // get saved EFLAGS off stack -- will be ignored
 699     __ pusha();                                  // push registers (eip = return address & msg are already pushed)
 700     BLOCK_COMMENT("call MacroAssembler::debug");
 701     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, MacroAssembler::debug32)));
 702     __ popa();
 703     __ ret(3 * wordSize);                        // pop arguments
 704     return start;
 705   }
 706 
 707   //
 708   //  Generate pre-barrier for array stores
 709   //
 710   //  Input:
 711   //     start   -  starting address
 712   //     end     -  element count
 713   void  gen_write_ref_array_pre_barrier(Register start, Register count) {
 714     assert_different_registers(start, count);
 715     BarrierSet* bs = Universe::heap()->barrier_set();
 716     switch (bs->kind()) {
 717       case BarrierSet::G1SATBCT:
 718       case BarrierSet::G1SATBCTLogging:
 719         {
 720           __ pusha();                      // push registers
 721           __ push(count);
 722           __ push(start);
 723           __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, BarrierSet::static_write_ref_array_pre)));
 724           __ addptr(rsp, 2*wordSize);
 725           __ popa();
 726         }
 727         break;
 728       case BarrierSet::CardTableModRef:
 729       case BarrierSet::CardTableExtension:
 730       case BarrierSet::ModRef:
 731         break;
 732       default      :
 733         ShouldNotReachHere();
 734 
 735     }
 736   }
 737 
 738 
 739   //
 740   // Generate a post-barrier for an array store
 741   //
 742   //     start    -  starting address
 743   //     count    -  element count
 744   //
 745   //  The two input registers are overwritten.
 746   //
 747   void  gen_write_ref_array_post_barrier(Register start, Register count) {
 748     BarrierSet* bs = Universe::heap()->barrier_set();
 749     assert_different_registers(start, count);
 750     switch (bs->kind()) {
 751       case BarrierSet::G1SATBCT:
 752       case BarrierSet::G1SATBCTLogging:
 753         {
 754           __ pusha();                      // push registers
 755           __ push(count);
 756           __ push(start);
 757           __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, BarrierSet::static_write_ref_array_post)));
 758           __ addptr(rsp, 2*wordSize);
 759           __ popa();
 760 
 761         }
 762         break;
 763 
 764       case BarrierSet::CardTableModRef:
 765       case BarrierSet::CardTableExtension:
 766         {
 767           CardTableModRefBS* ct = (CardTableModRefBS*)bs;
 768           assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust this code");
 769 
 770           Label L_loop;
 771           const Register end = count;  // elements count; end == start+count-1
 772           assert_different_registers(start, end);
 773 
 774           __ lea(end,  Address(start, count, Address::times_ptr, -wordSize));
 775           __ shrptr(start, CardTableModRefBS::card_shift);
 776           __ shrptr(end,   CardTableModRefBS::card_shift);
 777           __ subptr(end, start); // end --> count
 778         __ BIND(L_loop);
 779           intptr_t disp = (intptr_t) ct->byte_map_base;
 780           Address cardtable(start, count, Address::times_1, disp);
 781           __ movb(cardtable, 0);
 782           __ decrement(count);
 783           __ jcc(Assembler::greaterEqual, L_loop);
 784         }
 785         break;
 786       case BarrierSet::ModRef:
 787         break;
 788       default      :
 789         ShouldNotReachHere();
 790 
 791     }
 792   }
 793 
 794   // Copy 64 bytes chunks
 795   //
 796   // Inputs:
 797   //   from        - source array address
 798   //   to_from     - destination array address - from
 799   //   qword_count - 8-bytes element count, negative
 800   //
 801   void mmx_copy_forward(Register from, Register to_from, Register qword_count) {
 802     Label L_copy_64_bytes_loop, L_copy_64_bytes, L_copy_8_bytes, L_exit;
 803     // Copy 64-byte chunks
 804     __ jmpb(L_copy_64_bytes);
 805     __ align(16);
 806   __ BIND(L_copy_64_bytes_loop);
 807     __ movq(mmx0, Address(from, 0));
 808     __ movq(mmx1, Address(from, 8));
 809     __ movq(mmx2, Address(from, 16));
 810     __ movq(Address(from, to_from, Address::times_1, 0), mmx0);
 811     __ movq(mmx3, Address(from, 24));
 812     __ movq(Address(from, to_from, Address::times_1, 8), mmx1);
 813     __ movq(mmx4, Address(from, 32));
 814     __ movq(Address(from, to_from, Address::times_1, 16), mmx2);
 815     __ movq(mmx5, Address(from, 40));
 816     __ movq(Address(from, to_from, Address::times_1, 24), mmx3);
 817     __ movq(mmx6, Address(from, 48));
 818     __ movq(Address(from, to_from, Address::times_1, 32), mmx4);
 819     __ movq(mmx7, Address(from, 56));
 820     __ movq(Address(from, to_from, Address::times_1, 40), mmx5);
 821     __ movq(Address(from, to_from, Address::times_1, 48), mmx6);
 822     __ movq(Address(from, to_from, Address::times_1, 56), mmx7);
 823     __ addptr(from, 64);
 824   __ BIND(L_copy_64_bytes);
 825     __ subl(qword_count, 8);
 826     __ jcc(Assembler::greaterEqual, L_copy_64_bytes_loop);
 827     __ addl(qword_count, 8);
 828     __ jccb(Assembler::zero, L_exit);
 829     //
 830     // length is too short, just copy qwords
 831     //
 832   __ BIND(L_copy_8_bytes);
 833     __ movq(mmx0, Address(from, 0));
 834     __ movq(Address(from, to_from, Address::times_1), mmx0);
 835     __ addptr(from, 8);
 836     __ decrement(qword_count);
 837     __ jcc(Assembler::greater, L_copy_8_bytes);
 838   __ BIND(L_exit);
 839     __ emms();
 840   }
 841 
 842   address generate_disjoint_copy(BasicType t, bool aligned,
 843                                  Address::ScaleFactor sf,
 844                                  address* entry, const char *name) {
 845     __ align(CodeEntryAlignment);
 846     StubCodeMark mark(this, "StubRoutines", name);
 847     address start = __ pc();
 848 
 849     Label L_0_count, L_exit, L_skip_align1, L_skip_align2, L_copy_byte;
 850     Label L_copy_2_bytes, L_copy_4_bytes, L_copy_64_bytes;
 851 
 852     int shift = Address::times_ptr - sf;
 853 
 854     const Register from     = rsi;  // source array address
 855     const Register to       = rdi;  // destination array address
 856     const Register count    = rcx;  // elements count
 857     const Register to_from  = to;   // (to - from)
 858     const Register saved_to = rdx;  // saved destination array address
 859 
 860     __ enter(); // required for proper stackwalking of RuntimeStub frame
 861     __ push(rsi);
 862     __ push(rdi);
 863     __ movptr(from , Address(rsp, 12+ 4));
 864     __ movptr(to   , Address(rsp, 12+ 8));
 865     __ movl(count, Address(rsp, 12+ 12));
 866     if (t == T_OBJECT) {
 867       __ testl(count, count);
 868       __ jcc(Assembler::zero, L_0_count);
 869       gen_write_ref_array_pre_barrier(to, count);
 870       __ mov(saved_to, to);          // save 'to'
 871     }
 872 
 873     *entry = __ pc(); // Entry point from conjoint arraycopy stub.
 874     BLOCK_COMMENT("Entry:");
 875 
 876     __ subptr(to, from); // to --> to_from
 877     __ cmpl(count, 2<<shift); // Short arrays (< 8 bytes) copy by element
 878     __ jcc(Assembler::below, L_copy_4_bytes); // use unsigned cmp
 879     if (!aligned && (t == T_BYTE || t == T_SHORT)) {
 880       // align source address at 4 bytes address boundary
 881       if (t == T_BYTE) {
 882         // One byte misalignment happens only for byte arrays
 883         __ testl(from, 1);
 884         __ jccb(Assembler::zero, L_skip_align1);
 885         __ movb(rax, Address(from, 0));
 886         __ movb(Address(from, to_from, Address::times_1, 0), rax);
 887         __ increment(from);
 888         __ decrement(count);
 889       __ BIND(L_skip_align1);
 890       }
 891       // Two bytes misalignment happens only for byte and short (char) arrays
 892       __ testl(from, 2);
 893       __ jccb(Assembler::zero, L_skip_align2);
 894       __ movw(rax, Address(from, 0));
 895       __ movw(Address(from, to_from, Address::times_1, 0), rax);
 896       __ addptr(from, 2);
 897       __ subl(count, 1<<(shift-1));
 898     __ BIND(L_skip_align2);
 899     }
 900     if (!VM_Version::supports_mmx()) {
 901       __ mov(rax, count);      // save 'count'
 902       __ shrl(count, shift); // bytes count
 903       __ addptr(to_from, from);// restore 'to'
 904       __ rep_mov();
 905       __ subptr(to_from, from);// restore 'to_from'
 906       __ mov(count, rax);      // restore 'count'
 907       __ jmpb(L_copy_2_bytes); // all dwords were copied
 908     } else {
 909       // align to 8 bytes, we know we are 4 byte aligned to start
 910       __ testptr(from, 4);
 911       __ jccb(Assembler::zero, L_copy_64_bytes);
 912       __ movl(rax, Address(from, 0));
 913       __ movl(Address(from, to_from, Address::times_1, 0), rax);
 914       __ addptr(from, 4);
 915       __ subl(count, 1<<shift);
 916     __ BIND(L_copy_64_bytes);
 917       __ mov(rax, count);
 918       __ shrl(rax, shift+1);  // 8 bytes chunk count
 919       //
 920       // Copy 8-byte chunks through MMX registers, 8 per iteration of the loop
 921       //
 922       mmx_copy_forward(from, to_from, rax);
 923     }
 924     // copy tailing dword
 925   __ BIND(L_copy_4_bytes);
 926     __ testl(count, 1<<shift);
 927     __ jccb(Assembler::zero, L_copy_2_bytes);
 928     __ movl(rax, Address(from, 0));
 929     __ movl(Address(from, to_from, Address::times_1, 0), rax);
 930     if (t == T_BYTE || t == T_SHORT) {
 931       __ addptr(from, 4);
 932     __ BIND(L_copy_2_bytes);
 933       // copy tailing word
 934       __ testl(count, 1<<(shift-1));
 935       __ jccb(Assembler::zero, L_copy_byte);
 936       __ movw(rax, Address(from, 0));
 937       __ movw(Address(from, to_from, Address::times_1, 0), rax);
 938       if (t == T_BYTE) {
 939         __ addptr(from, 2);
 940       __ BIND(L_copy_byte);
 941         // copy tailing byte
 942         __ testl(count, 1);
 943         __ jccb(Assembler::zero, L_exit);
 944         __ movb(rax, Address(from, 0));
 945         __ movb(Address(from, to_from, Address::times_1, 0), rax);
 946       __ BIND(L_exit);
 947       } else {
 948       __ BIND(L_copy_byte);
 949       }
 950     } else {
 951     __ BIND(L_copy_2_bytes);
 952     }
 953 
 954     if (t == T_OBJECT) {
 955       __ movl(count, Address(rsp, 12+12)); // reread 'count'
 956       __ mov(to, saved_to); // restore 'to'
 957       gen_write_ref_array_post_barrier(to, count);
 958     __ BIND(L_0_count);
 959     }
 960     inc_copy_counter_np(t);
 961     __ pop(rdi);
 962     __ pop(rsi);
 963     __ leave(); // required for proper stackwalking of RuntimeStub frame
 964     __ xorptr(rax, rax); // return 0
 965     __ ret(0);
 966     return start;
 967   }
 968 
 969 
 970   address generate_conjoint_copy(BasicType t, bool aligned,
 971                                  Address::ScaleFactor sf,
 972                                  address nooverlap_target,
 973                                  address* entry, const char *name) {
 974     __ align(CodeEntryAlignment);
 975     StubCodeMark mark(this, "StubRoutines", name);
 976     address start = __ pc();
 977 
 978     Label L_0_count, L_exit, L_skip_align1, L_skip_align2, L_copy_byte;
 979     Label L_copy_2_bytes, L_copy_4_bytes, L_copy_8_bytes, L_copy_8_bytes_loop;
 980 
 981     int shift = Address::times_ptr - sf;
 982 
 983     const Register src   = rax;  // source array address
 984     const Register dst   = rdx;  // destination array address
 985     const Register from  = rsi;  // source array address
 986     const Register to    = rdi;  // destination array address
 987     const Register count = rcx;  // elements count
 988     const Register end   = rax;  // array end address
 989 
 990     __ enter(); // required for proper stackwalking of RuntimeStub frame
 991     __ push(rsi);
 992     __ push(rdi);
 993     __ movptr(src  , Address(rsp, 12+ 4));   // from
 994     __ movptr(dst  , Address(rsp, 12+ 8));   // to
 995     __ movl2ptr(count, Address(rsp, 12+12)); // count
 996     if (t == T_OBJECT) {
 997        gen_write_ref_array_pre_barrier(dst, count);
 998     }
 999 
1000     if (entry != NULL) {
1001       *entry = __ pc(); // Entry point from generic arraycopy stub.
1002       BLOCK_COMMENT("Entry:");
1003     }
1004 
1005     if (t == T_OBJECT) {
1006       __ testl(count, count);
1007       __ jcc(Assembler::zero, L_0_count);
1008     }
1009     __ mov(from, src);
1010     __ mov(to  , dst);
1011 
1012     // arrays overlap test
1013     RuntimeAddress nooverlap(nooverlap_target);
1014     __ cmpptr(dst, src);
1015     __ lea(end, Address(src, count, sf, 0)); // src + count * elem_size
1016     __ jump_cc(Assembler::belowEqual, nooverlap);
1017     __ cmpptr(dst, end);
1018     __ jump_cc(Assembler::aboveEqual, nooverlap);
1019 
1020     // copy from high to low
1021     __ cmpl(count, 2<<shift); // Short arrays (< 8 bytes) copy by element
1022     __ jcc(Assembler::below, L_copy_4_bytes); // use unsigned cmp
1023     if (t == T_BYTE || t == T_SHORT) {
1024       // Align the end of destination array at 4 bytes address boundary
1025       __ lea(end, Address(dst, count, sf, 0));
1026       if (t == T_BYTE) {
1027         // One byte misalignment happens only for byte arrays
1028         __ testl(end, 1);
1029         __ jccb(Assembler::zero, L_skip_align1);
1030         __ decrement(count);
1031         __ movb(rdx, Address(from, count, sf, 0));
1032         __ movb(Address(to, count, sf, 0), rdx);
1033       __ BIND(L_skip_align1);
1034       }
1035       // Two bytes misalignment happens only for byte and short (char) arrays
1036       __ testl(end, 2);
1037       __ jccb(Assembler::zero, L_skip_align2);
1038       __ subptr(count, 1<<(shift-1));
1039       __ movw(rdx, Address(from, count, sf, 0));
1040       __ movw(Address(to, count, sf, 0), rdx);
1041     __ BIND(L_skip_align2);
1042       __ cmpl(count, 2<<shift); // Short arrays (< 8 bytes) copy by element
1043       __ jcc(Assembler::below, L_copy_4_bytes);
1044     }
1045 
1046     if (!VM_Version::supports_mmx()) {
1047       __ std();
1048       __ mov(rax, count); // Save 'count'
1049       __ mov(rdx, to);    // Save 'to'
1050       __ lea(rsi, Address(from, count, sf, -4));
1051       __ lea(rdi, Address(to  , count, sf, -4));
1052       __ shrptr(count, shift); // bytes count
1053       __ rep_mov();
1054       __ cld();
1055       __ mov(count, rax); // restore 'count'
1056       __ andl(count, (1<<shift)-1);      // mask the number of rest elements
1057       __ movptr(from, Address(rsp, 12+4)); // reread 'from'
1058       __ mov(to, rdx);   // restore 'to'
1059       __ jmpb(L_copy_2_bytes); // all dword were copied
1060    } else {
1061       // Align to 8 bytes the end of array. It is aligned to 4 bytes already.
1062       __ testptr(end, 4);
1063       __ jccb(Assembler::zero, L_copy_8_bytes);
1064       __ subl(count, 1<<shift);
1065       __ movl(rdx, Address(from, count, sf, 0));
1066       __ movl(Address(to, count, sf, 0), rdx);
1067       __ jmpb(L_copy_8_bytes);
1068 
1069       __ align(16);
1070       // Move 8 bytes
1071     __ BIND(L_copy_8_bytes_loop);
1072       __ movq(mmx0, Address(from, count, sf, 0));
1073       __ movq(Address(to, count, sf, 0), mmx0);
1074     __ BIND(L_copy_8_bytes);
1075       __ subl(count, 2<<shift);
1076       __ jcc(Assembler::greaterEqual, L_copy_8_bytes_loop);
1077       __ addl(count, 2<<shift);
1078       __ emms();
1079     }
1080   __ BIND(L_copy_4_bytes);
1081     // copy prefix qword
1082     __ testl(count, 1<<shift);
1083     __ jccb(Assembler::zero, L_copy_2_bytes);
1084     __ movl(rdx, Address(from, count, sf, -4));
1085     __ movl(Address(to, count, sf, -4), rdx);
1086 
1087     if (t == T_BYTE || t == T_SHORT) {
1088         __ subl(count, (1<<shift));
1089       __ BIND(L_copy_2_bytes);
1090         // copy prefix dword
1091         __ testl(count, 1<<(shift-1));
1092         __ jccb(Assembler::zero, L_copy_byte);
1093         __ movw(rdx, Address(from, count, sf, -2));
1094         __ movw(Address(to, count, sf, -2), rdx);
1095         if (t == T_BYTE) {
1096           __ subl(count, 1<<(shift-1));
1097         __ BIND(L_copy_byte);
1098           // copy prefix byte
1099           __ testl(count, 1);
1100           __ jccb(Assembler::zero, L_exit);
1101           __ movb(rdx, Address(from, 0));
1102           __ movb(Address(to, 0), rdx);
1103         __ BIND(L_exit);
1104         } else {
1105         __ BIND(L_copy_byte);
1106         }
1107     } else {
1108     __ BIND(L_copy_2_bytes);
1109     }
1110     if (t == T_OBJECT) {
1111       __ movl2ptr(count, Address(rsp, 12+12)); // reread count
1112       gen_write_ref_array_post_barrier(to, count);
1113     __ BIND(L_0_count);
1114     }
1115     inc_copy_counter_np(t);
1116     __ pop(rdi);
1117     __ pop(rsi);
1118     __ leave(); // required for proper stackwalking of RuntimeStub frame
1119     __ xorptr(rax, rax); // return 0
1120     __ ret(0);
1121     return start;
1122   }
1123 
1124 
1125   address generate_disjoint_long_copy(address* entry, const char *name) {
1126     __ align(CodeEntryAlignment);
1127     StubCodeMark mark(this, "StubRoutines", name);
1128     address start = __ pc();
1129 
1130     Label L_copy_8_bytes, L_copy_8_bytes_loop;
1131     const Register from       = rax;  // source array address
1132     const Register to         = rdx;  // destination array address
1133     const Register count      = rcx;  // elements count
1134     const Register to_from    = rdx;  // (to - from)
1135 
1136     __ enter(); // required for proper stackwalking of RuntimeStub frame
1137     __ movptr(from , Address(rsp, 8+0));       // from
1138     __ movptr(to   , Address(rsp, 8+4));       // to
1139     __ movl2ptr(count, Address(rsp, 8+8));     // count
1140 
1141     *entry = __ pc(); // Entry point from conjoint arraycopy stub.
1142     BLOCK_COMMENT("Entry:");
1143 
1144     __ subptr(to, from); // to --> to_from
1145     if (VM_Version::supports_mmx()) {
1146       mmx_copy_forward(from, to_from, count);
1147     } else {
1148       __ jmpb(L_copy_8_bytes);
1149       __ align(16);
1150     __ BIND(L_copy_8_bytes_loop);
1151       __ fild_d(Address(from, 0));
1152       __ fistp_d(Address(from, to_from, Address::times_1));
1153       __ addptr(from, 8);
1154     __ BIND(L_copy_8_bytes);
1155       __ decrement(count);
1156       __ jcc(Assembler::greaterEqual, L_copy_8_bytes_loop);
1157     }
1158     inc_copy_counter_np(T_LONG);
1159     __ leave(); // required for proper stackwalking of RuntimeStub frame
1160     __ xorptr(rax, rax); // return 0
1161     __ ret(0);
1162     return start;
1163   }
1164 
1165   address generate_conjoint_long_copy(address nooverlap_target,
1166                                       address* entry, const char *name) {
1167     __ align(CodeEntryAlignment);
1168     StubCodeMark mark(this, "StubRoutines", name);
1169     address start = __ pc();
1170 
1171     Label L_copy_8_bytes, L_copy_8_bytes_loop;
1172     const Register from       = rax;  // source array address
1173     const Register to         = rdx;  // destination array address
1174     const Register count      = rcx;  // elements count
1175     const Register end_from   = rax;  // source array end address
1176 
1177     __ enter(); // required for proper stackwalking of RuntimeStub frame
1178     __ movptr(from , Address(rsp, 8+0));       // from
1179     __ movptr(to   , Address(rsp, 8+4));       // to
1180     __ movl2ptr(count, Address(rsp, 8+8));     // count
1181 
1182     *entry = __ pc(); // Entry point from generic arraycopy stub.
1183     BLOCK_COMMENT("Entry:");
1184 
1185     // arrays overlap test
1186     __ cmpptr(to, from);
1187     RuntimeAddress nooverlap(nooverlap_target);
1188     __ jump_cc(Assembler::belowEqual, nooverlap);
1189     __ lea(end_from, Address(from, count, Address::times_8, 0));
1190     __ cmpptr(to, end_from);
1191     __ movptr(from, Address(rsp, 8));  // from
1192     __ jump_cc(Assembler::aboveEqual, nooverlap);
1193 
1194     __ jmpb(L_copy_8_bytes);
1195 
1196     __ align(16);
1197   __ BIND(L_copy_8_bytes_loop);
1198     if (VM_Version::supports_mmx()) {
1199       __ movq(mmx0, Address(from, count, Address::times_8));
1200       __ movq(Address(to, count, Address::times_8), mmx0);
1201     } else {
1202       __ fild_d(Address(from, count, Address::times_8));
1203       __ fistp_d(Address(to, count, Address::times_8));
1204     }
1205   __ BIND(L_copy_8_bytes);
1206     __ decrement(count);
1207     __ jcc(Assembler::greaterEqual, L_copy_8_bytes_loop);
1208 
1209     if (VM_Version::supports_mmx()) {
1210       __ emms();
1211     }
1212     inc_copy_counter_np(T_LONG);
1213     __ leave(); // required for proper stackwalking of RuntimeStub frame
1214     __ xorptr(rax, rax); // return 0
1215     __ ret(0);
1216     return start;
1217   }
1218 
1219 
1220   // Helper for generating a dynamic type check.
1221   // The sub_klass must be one of {rbx, rdx, rsi}.
1222   // The temp is killed.
1223   void generate_type_check(Register sub_klass,
1224                            Address& super_check_offset_addr,
1225                            Address& super_klass_addr,
1226                            Register temp,
1227                            Label* L_success_ptr, Label* L_failure_ptr) {
1228     BLOCK_COMMENT("type_check:");
1229 
1230     Label L_fallthrough;
1231     bool fall_through_on_success = (L_success_ptr == NULL);
1232     if (fall_through_on_success) {
1233       L_success_ptr = &L_fallthrough;
1234     } else {
1235       L_failure_ptr = &L_fallthrough;
1236     }
1237     Label& L_success = *L_success_ptr;
1238     Label& L_failure = *L_failure_ptr;
1239 
1240     assert_different_registers(sub_klass, temp);
1241 
1242     // a couple of useful fields in sub_klass:
1243     int ss_offset = (klassOopDesc::header_size() * HeapWordSize +
1244                      Klass::secondary_supers_offset_in_bytes());
1245     int sc_offset = (klassOopDesc::header_size() * HeapWordSize +
1246                      Klass::secondary_super_cache_offset_in_bytes());
1247     Address secondary_supers_addr(sub_klass, ss_offset);
1248     Address super_cache_addr(     sub_klass, sc_offset);
1249 
1250     // if the pointers are equal, we are done (e.g., String[] elements)
1251     __ cmpptr(sub_klass, super_klass_addr);
1252     __ jcc(Assembler::equal, L_success);
1253 
1254     // check the supertype display:
1255     __ movl2ptr(temp, super_check_offset_addr);
1256     Address super_check_addr(sub_klass, temp, Address::times_1, 0);
1257     __ movptr(temp, super_check_addr); // load displayed supertype
1258     __ cmpptr(temp, super_klass_addr); // test the super type
1259     __ jcc(Assembler::equal, L_success);
1260 
1261     // if it was a primary super, we can just fail immediately
1262     __ cmpl(super_check_offset_addr, sc_offset);
1263     __ jcc(Assembler::notEqual, L_failure);
1264 
1265     // Now do a linear scan of the secondary super-klass chain.
1266     // This code is rarely used, so simplicity is a virtue here.
1267     inc_counter_np(SharedRuntime::_partial_subtype_ctr);
1268     {
1269       // The repne_scan instruction uses fixed registers, which we must spill.
1270       // (We need a couple more temps in any case.)
1271       __ push(rax);
1272       __ push(rcx);
1273       __ push(rdi);
1274       assert_different_registers(sub_klass, rax, rcx, rdi);
1275 
1276       __ movptr(rdi, secondary_supers_addr);
1277       // Load the array length.
1278       __ movl(rcx, Address(rdi, arrayOopDesc::length_offset_in_bytes()));
1279       // Skip to start of data.
1280       __ addptr(rdi, arrayOopDesc::base_offset_in_bytes(T_OBJECT));
1281       // Scan rcx words at [edi] for occurance of rax,
1282       // Set NZ/Z based on last compare
1283       __ movptr(rax, super_klass_addr);
1284       __ repne_scan();
1285 
1286       // Unspill the temp. registers:
1287       __ pop(rdi);
1288       __ pop(rcx);
1289       __ pop(rax);
1290     }
1291     __ jcc(Assembler::notEqual, L_failure);
1292 
1293     // Success.  Cache the super we found and proceed in triumph.
1294     __ movptr(temp, super_klass_addr); // note: rax, is dead
1295     __ movptr(super_cache_addr, temp);
1296 
1297     if (!fall_through_on_success)
1298       __ jmp(L_success);
1299 
1300     // Fall through on failure!
1301     __ bind(L_fallthrough);
1302   }
1303 
1304   //
1305   //  Generate checkcasting array copy stub
1306   //
1307   //  Input:
1308   //    4(rsp)   - source array address
1309   //    8(rsp)   - destination array address
1310   //   12(rsp)   - element count, can be zero
1311   //   16(rsp)   - size_t ckoff (super_check_offset)
1312   //   20(rsp)   - oop ckval (super_klass)
1313   //
1314   //  Output:
1315   //    rax, ==  0  -  success
1316   //    rax, == -1^K - failure, where K is partial transfer count
1317   //
1318   address generate_checkcast_copy(const char *name, address* entry) {
1319     __ align(CodeEntryAlignment);
1320     StubCodeMark mark(this, "StubRoutines", name);
1321     address start = __ pc();
1322 
1323     Label L_load_element, L_store_element, L_do_card_marks, L_done;
1324 
1325     // register use:
1326     //  rax, rdx, rcx -- loop control (end_from, end_to, count)
1327     //  rdi, rsi      -- element access (oop, klass)
1328     //  rbx,           -- temp
1329     const Register from       = rax;    // source array address
1330     const Register to         = rdx;    // destination array address
1331     const Register length     = rcx;    // elements count
1332     const Register elem       = rdi;    // each oop copied
1333     const Register elem_klass = rsi;    // each elem._klass (sub_klass)
1334     const Register temp       = rbx;    // lone remaining temp
1335 
1336     __ enter(); // required for proper stackwalking of RuntimeStub frame
1337 
1338     __ push(rsi);
1339     __ push(rdi);
1340     __ push(rbx);
1341 
1342     Address   from_arg(rsp, 16+ 4);     // from
1343     Address     to_arg(rsp, 16+ 8);     // to
1344     Address length_arg(rsp, 16+12);     // elements count
1345     Address  ckoff_arg(rsp, 16+16);     // super_check_offset
1346     Address  ckval_arg(rsp, 16+20);     // super_klass
1347 
1348     // Load up:
1349     __ movptr(from,     from_arg);
1350     __ movptr(to,         to_arg);
1351     __ movl2ptr(length, length_arg);
1352 
1353     *entry = __ pc(); // Entry point from generic arraycopy stub.
1354     BLOCK_COMMENT("Entry:");
1355 
1356     //---------------------------------------------------------------
1357     // Assembler stub will be used for this call to arraycopy
1358     // if the two arrays are subtypes of Object[] but the
1359     // destination array type is not equal to or a supertype
1360     // of the source type.  Each element must be separately
1361     // checked.
1362 
1363     // Loop-invariant addresses.  They are exclusive end pointers.
1364     Address end_from_addr(from, length, Address::times_ptr, 0);
1365     Address   end_to_addr(to,   length, Address::times_ptr, 0);
1366 
1367     Register end_from = from;           // re-use
1368     Register end_to   = to;             // re-use
1369     Register count    = length;         // re-use
1370 
1371     // Loop-variant addresses.  They assume post-incremented count < 0.
1372     Address from_element_addr(end_from, count, Address::times_ptr, 0);
1373     Address   to_element_addr(end_to,   count, Address::times_ptr, 0);
1374     Address elem_klass_addr(elem, oopDesc::klass_offset_in_bytes());
1375 
1376     // Copy from low to high addresses, indexed from the end of each array.
1377     gen_write_ref_array_pre_barrier(to, count);
1378     __ lea(end_from, end_from_addr);
1379     __ lea(end_to,   end_to_addr);
1380     assert(length == count, "");        // else fix next line:
1381     __ negptr(count);                   // negate and test the length
1382     __ jccb(Assembler::notZero, L_load_element);
1383 
1384     // Empty array:  Nothing to do.
1385     __ xorptr(rax, rax);                  // return 0 on (trivial) success
1386     __ jmp(L_done);
1387 
1388     // ======== begin loop ========
1389     // (Loop is rotated; its entry is L_load_element.)
1390     // Loop control:
1391     //   for (count = -count; count != 0; count++)
1392     // Base pointers src, dst are biased by 8*count,to last element.
1393     __ align(16);
1394 
1395     __ BIND(L_store_element);
1396     __ movptr(to_element_addr, elem);     // store the oop
1397     __ increment(count);                // increment the count toward zero
1398     __ jccb(Assembler::zero, L_do_card_marks);
1399 
1400     // ======== loop entry is here ========
1401     __ BIND(L_load_element);
1402     __ movptr(elem, from_element_addr);   // load the oop
1403     __ testptr(elem, elem);
1404     __ jccb(Assembler::zero, L_store_element);
1405 
1406     // (Could do a trick here:  Remember last successful non-null
1407     // element stored and make a quick oop equality check on it.)
1408 
1409     __ movptr(elem_klass, elem_klass_addr); // query the object klass
1410     generate_type_check(elem_klass, ckoff_arg, ckval_arg, temp,
1411                         &L_store_element, NULL);
1412       // (On fall-through, we have failed the element type check.)
1413     // ======== end loop ========
1414 
1415     // It was a real error; we must depend on the caller to finish the job.
1416     // Register "count" = -1 * number of *remaining* oops, length_arg = *total* oops.
1417     // Emit GC store barriers for the oops we have copied (length_arg + count),
1418     // and report their number to the caller.
1419     __ addl(count, length_arg);         // transfers = (length - remaining)
1420     __ movl2ptr(rax, count);            // save the value
1421     __ notptr(rax);                     // report (-1^K) to caller
1422     __ movptr(to, to_arg);              // reload
1423     assert_different_registers(to, count, rax);
1424     gen_write_ref_array_post_barrier(to, count);
1425     __ jmpb(L_done);
1426 
1427     // Come here on success only.
1428     __ BIND(L_do_card_marks);
1429     __ movl2ptr(count, length_arg);
1430     __ movptr(to, to_arg);                // reload
1431     gen_write_ref_array_post_barrier(to, count);
1432     __ xorptr(rax, rax);                  // return 0 on success
1433 
1434     // Common exit point (success or failure).
1435     __ BIND(L_done);
1436     __ pop(rbx);
1437     __ pop(rdi);
1438     __ pop(rsi);
1439     inc_counter_np(SharedRuntime::_checkcast_array_copy_ctr);
1440     __ leave(); // required for proper stackwalking of RuntimeStub frame
1441     __ ret(0);
1442 
1443     return start;
1444   }
1445 
1446   //
1447   //  Generate 'unsafe' array copy stub
1448   //  Though just as safe as the other stubs, it takes an unscaled
1449   //  size_t argument instead of an element count.
1450   //
1451   //  Input:
1452   //    4(rsp)   - source array address
1453   //    8(rsp)   - destination array address
1454   //   12(rsp)   - byte count, can be zero
1455   //
1456   //  Output:
1457   //    rax, ==  0  -  success
1458   //    rax, == -1  -  need to call System.arraycopy
1459   //
1460   // Examines the alignment of the operands and dispatches
1461   // to a long, int, short, or byte copy loop.
1462   //
1463   address generate_unsafe_copy(const char *name,
1464                                address byte_copy_entry,
1465                                address short_copy_entry,
1466                                address int_copy_entry,
1467                                address long_copy_entry) {
1468 
1469     Label L_long_aligned, L_int_aligned, L_short_aligned;
1470 
1471     __ align(CodeEntryAlignment);
1472     StubCodeMark mark(this, "StubRoutines", name);
1473     address start = __ pc();
1474 
1475     const Register from       = rax;  // source array address
1476     const Register to         = rdx;  // destination array address
1477     const Register count      = rcx;  // elements count
1478 
1479     __ enter(); // required for proper stackwalking of RuntimeStub frame
1480     __ push(rsi);
1481     __ push(rdi);
1482     Address  from_arg(rsp, 12+ 4);      // from
1483     Address    to_arg(rsp, 12+ 8);      // to
1484     Address count_arg(rsp, 12+12);      // byte count
1485 
1486     // Load up:
1487     __ movptr(from ,  from_arg);
1488     __ movptr(to   ,    to_arg);
1489     __ movl2ptr(count, count_arg);
1490 
1491     // bump this on entry, not on exit:
1492     inc_counter_np(SharedRuntime::_unsafe_array_copy_ctr);
1493 
1494     const Register bits = rsi;
1495     __ mov(bits, from);
1496     __ orptr(bits, to);
1497     __ orptr(bits, count);
1498 
1499     __ testl(bits, BytesPerLong-1);
1500     __ jccb(Assembler::zero, L_long_aligned);
1501 
1502     __ testl(bits, BytesPerInt-1);
1503     __ jccb(Assembler::zero, L_int_aligned);
1504 
1505     __ testl(bits, BytesPerShort-1);
1506     __ jump_cc(Assembler::notZero, RuntimeAddress(byte_copy_entry));
1507 
1508     __ BIND(L_short_aligned);
1509     __ shrptr(count, LogBytesPerShort); // size => short_count
1510     __ movl(count_arg, count);          // update 'count'
1511     __ jump(RuntimeAddress(short_copy_entry));
1512 
1513     __ BIND(L_int_aligned);
1514     __ shrptr(count, LogBytesPerInt); // size => int_count
1515     __ movl(count_arg, count);          // update 'count'
1516     __ jump(RuntimeAddress(int_copy_entry));
1517 
1518     __ BIND(L_long_aligned);
1519     __ shrptr(count, LogBytesPerLong); // size => qword_count
1520     __ movl(count_arg, count);          // update 'count'
1521     __ pop(rdi); // Do pops here since jlong_arraycopy stub does not do it.
1522     __ pop(rsi);
1523     __ jump(RuntimeAddress(long_copy_entry));
1524 
1525     return start;
1526   }
1527 
1528 
1529   // Perform range checks on the proposed arraycopy.
1530   // Smashes src_pos and dst_pos.  (Uses them up for temps.)
1531   void arraycopy_range_checks(Register src,
1532                               Register src_pos,
1533                               Register dst,
1534                               Register dst_pos,
1535                               Address& length,
1536                               Label& L_failed) {
1537     BLOCK_COMMENT("arraycopy_range_checks:");
1538     const Register src_end = src_pos;   // source array end position
1539     const Register dst_end = dst_pos;   // destination array end position
1540     __ addl(src_end, length); // src_pos + length
1541     __ addl(dst_end, length); // dst_pos + length
1542 
1543     //  if (src_pos + length > arrayOop(src)->length() ) FAIL;
1544     __ cmpl(src_end, Address(src, arrayOopDesc::length_offset_in_bytes()));
1545     __ jcc(Assembler::above, L_failed);
1546 
1547     //  if (dst_pos + length > arrayOop(dst)->length() ) FAIL;
1548     __ cmpl(dst_end, Address(dst, arrayOopDesc::length_offset_in_bytes()));
1549     __ jcc(Assembler::above, L_failed);
1550 
1551     BLOCK_COMMENT("arraycopy_range_checks done");
1552   }
1553 
1554 
1555   //
1556   //  Generate generic array copy stubs
1557   //
1558   //  Input:
1559   //     4(rsp)    -  src oop
1560   //     8(rsp)    -  src_pos
1561   //    12(rsp)    -  dst oop
1562   //    16(rsp)    -  dst_pos
1563   //    20(rsp)    -  element count
1564   //
1565   //  Output:
1566   //    rax, ==  0  -  success
1567   //    rax, == -1^K - failure, where K is partial transfer count
1568   //
1569   address generate_generic_copy(const char *name,
1570                                 address entry_jbyte_arraycopy,
1571                                 address entry_jshort_arraycopy,
1572                                 address entry_jint_arraycopy,
1573                                 address entry_oop_arraycopy,
1574                                 address entry_jlong_arraycopy,
1575                                 address entry_checkcast_arraycopy) {
1576     Label L_failed, L_failed_0, L_objArray;
1577 
1578     { int modulus = CodeEntryAlignment;
1579       int target  = modulus - 5; // 5 = sizeof jmp(L_failed)
1580       int advance = target - (__ offset() % modulus);
1581       if (advance < 0)  advance += modulus;
1582       if (advance > 0)  __ nop(advance);
1583     }
1584     StubCodeMark mark(this, "StubRoutines", name);
1585 
1586     // Short-hop target to L_failed.  Makes for denser prologue code.
1587     __ BIND(L_failed_0);
1588     __ jmp(L_failed);
1589     assert(__ offset() % CodeEntryAlignment == 0, "no further alignment needed");
1590 
1591     __ align(CodeEntryAlignment);
1592     address start = __ pc();
1593 
1594     __ enter(); // required for proper stackwalking of RuntimeStub frame
1595     __ push(rsi);
1596     __ push(rdi);
1597 
1598     // bump this on entry, not on exit:
1599     inc_counter_np(SharedRuntime::_generic_array_copy_ctr);
1600 
1601     // Input values
1602     Address SRC     (rsp, 12+ 4);
1603     Address SRC_POS (rsp, 12+ 8);
1604     Address DST     (rsp, 12+12);
1605     Address DST_POS (rsp, 12+16);
1606     Address LENGTH  (rsp, 12+20);
1607 
1608     //-----------------------------------------------------------------------
1609     // Assembler stub will be used for this call to arraycopy
1610     // if the following conditions are met:
1611     //
1612     // (1) src and dst must not be null.
1613     // (2) src_pos must not be negative.
1614     // (3) dst_pos must not be negative.
1615     // (4) length  must not be negative.
1616     // (5) src klass and dst klass should be the same and not NULL.
1617     // (6) src and dst should be arrays.
1618     // (7) src_pos + length must not exceed length of src.
1619     // (8) dst_pos + length must not exceed length of dst.
1620     //
1621 
1622     const Register src     = rax;       // source array oop
1623     const Register src_pos = rsi;
1624     const Register dst     = rdx;       // destination array oop
1625     const Register dst_pos = rdi;
1626     const Register length  = rcx;       // transfer count
1627 
1628     //  if (src == NULL) return -1;
1629     __ movptr(src, SRC);      // src oop
1630     __ testptr(src, src);
1631     __ jccb(Assembler::zero, L_failed_0);
1632 
1633     //  if (src_pos < 0) return -1;
1634     __ movl2ptr(src_pos, SRC_POS);  // src_pos
1635     __ testl(src_pos, src_pos);
1636     __ jccb(Assembler::negative, L_failed_0);
1637 
1638     //  if (dst == NULL) return -1;
1639     __ movptr(dst, DST);      // dst oop
1640     __ testptr(dst, dst);
1641     __ jccb(Assembler::zero, L_failed_0);
1642 
1643     //  if (dst_pos < 0) return -1;
1644     __ movl2ptr(dst_pos, DST_POS);  // dst_pos
1645     __ testl(dst_pos, dst_pos);
1646     __ jccb(Assembler::negative, L_failed_0);
1647 
1648     //  if (length < 0) return -1;
1649     __ movl2ptr(length, LENGTH);   // length
1650     __ testl(length, length);
1651     __ jccb(Assembler::negative, L_failed_0);
1652 
1653     //  if (src->klass() == NULL) return -1;
1654     Address src_klass_addr(src, oopDesc::klass_offset_in_bytes());
1655     Address dst_klass_addr(dst, oopDesc::klass_offset_in_bytes());
1656     const Register rcx_src_klass = rcx;    // array klass
1657     __ movptr(rcx_src_klass, Address(src, oopDesc::klass_offset_in_bytes()));
1658 
1659 #ifdef ASSERT
1660     //  assert(src->klass() != NULL);
1661     BLOCK_COMMENT("assert klasses not null");
1662     { Label L1, L2;
1663       __ testptr(rcx_src_klass, rcx_src_klass);
1664       __ jccb(Assembler::notZero, L2);   // it is broken if klass is NULL
1665       __ bind(L1);
1666       __ stop("broken null klass");
1667       __ bind(L2);
1668       __ cmpptr(dst_klass_addr, (int32_t)NULL_WORD);
1669       __ jccb(Assembler::equal, L1);      // this would be broken also
1670       BLOCK_COMMENT("assert done");
1671     }
1672 #endif //ASSERT
1673 
1674     // Load layout helper (32-bits)
1675     //
1676     //  |array_tag|     | header_size | element_type |     |log2_element_size|
1677     // 32        30    24            16              8     2                 0
1678     //
1679     //   array_tag: typeArray = 0x3, objArray = 0x2, non-array = 0x0
1680     //
1681 
1682     int lh_offset = klassOopDesc::header_size() * HeapWordSize +
1683                     Klass::layout_helper_offset_in_bytes();
1684     Address src_klass_lh_addr(rcx_src_klass, lh_offset);
1685 
1686     // Handle objArrays completely differently...
1687     jint objArray_lh = Klass::array_layout_helper(T_OBJECT);
1688     __ cmpl(src_klass_lh_addr, objArray_lh);
1689     __ jcc(Assembler::equal, L_objArray);
1690 
1691     //  if (src->klass() != dst->klass()) return -1;
1692     __ cmpptr(rcx_src_klass, dst_klass_addr);
1693     __ jccb(Assembler::notEqual, L_failed_0);
1694 
1695     const Register rcx_lh = rcx;  // layout helper
1696     assert(rcx_lh == rcx_src_klass, "known alias");
1697     __ movl(rcx_lh, src_klass_lh_addr);
1698 
1699     //  if (!src->is_Array()) return -1;
1700     __ cmpl(rcx_lh, Klass::_lh_neutral_value);
1701     __ jcc(Assembler::greaterEqual, L_failed_0); // signed cmp
1702 
1703     // At this point, it is known to be a typeArray (array_tag 0x3).
1704 #ifdef ASSERT
1705     { Label L;
1706       __ cmpl(rcx_lh, (Klass::_lh_array_tag_type_value << Klass::_lh_array_tag_shift));
1707       __ jcc(Assembler::greaterEqual, L); // signed cmp
1708       __ stop("must be a primitive array");
1709       __ bind(L);
1710     }
1711 #endif
1712 
1713     assert_different_registers(src, src_pos, dst, dst_pos, rcx_lh);
1714     arraycopy_range_checks(src, src_pos, dst, dst_pos, LENGTH, L_failed);
1715 
1716     // typeArrayKlass
1717     //
1718     // src_addr = (src + array_header_in_bytes()) + (src_pos << log2elemsize);
1719     // dst_addr = (dst + array_header_in_bytes()) + (dst_pos << log2elemsize);
1720     //
1721     const Register rsi_offset = rsi; // array offset
1722     const Register src_array  = src; // src array offset
1723     const Register dst_array  = dst; // dst array offset
1724     const Register rdi_elsize = rdi; // log2 element size
1725 
1726     __ mov(rsi_offset, rcx_lh);
1727     __ shrptr(rsi_offset, Klass::_lh_header_size_shift);
1728     __ andptr(rsi_offset, Klass::_lh_header_size_mask);   // array_offset
1729     __ addptr(src_array, rsi_offset);  // src array offset
1730     __ addptr(dst_array, rsi_offset);  // dst array offset
1731     __ andptr(rcx_lh, Klass::_lh_log2_element_size_mask); // log2 elsize
1732 
1733     // next registers should be set before the jump to corresponding stub
1734     const Register from       = src; // source array address
1735     const Register to         = dst; // destination array address
1736     const Register count      = rcx; // elements count
1737     // some of them should be duplicated on stack
1738 #define FROM   Address(rsp, 12+ 4)
1739 #define TO     Address(rsp, 12+ 8)   // Not used now
1740 #define COUNT  Address(rsp, 12+12)   // Only for oop arraycopy
1741 
1742     BLOCK_COMMENT("scale indexes to element size");
1743     __ movl2ptr(rsi, SRC_POS);  // src_pos
1744     __ shlptr(rsi);             // src_pos << rcx (log2 elsize)
1745     assert(src_array == from, "");
1746     __ addptr(from, rsi);       // from = src_array + SRC_POS << log2 elsize
1747     __ movl2ptr(rdi, DST_POS);  // dst_pos
1748     __ shlptr(rdi);             // dst_pos << rcx (log2 elsize)
1749     assert(dst_array == to, "");
1750     __ addptr(to,  rdi);        // to   = dst_array + DST_POS << log2 elsize
1751     __ movptr(FROM, from);      // src_addr
1752     __ mov(rdi_elsize, rcx_lh); // log2 elsize
1753     __ movl2ptr(count, LENGTH); // elements count
1754 
1755     BLOCK_COMMENT("choose copy loop based on element size");
1756     __ cmpl(rdi_elsize, 0);
1757 
1758     __ jump_cc(Assembler::equal, RuntimeAddress(entry_jbyte_arraycopy));
1759     __ cmpl(rdi_elsize, LogBytesPerShort);
1760     __ jump_cc(Assembler::equal, RuntimeAddress(entry_jshort_arraycopy));
1761     __ cmpl(rdi_elsize, LogBytesPerInt);
1762     __ jump_cc(Assembler::equal, RuntimeAddress(entry_jint_arraycopy));
1763 #ifdef ASSERT
1764     __ cmpl(rdi_elsize, LogBytesPerLong);
1765     __ jccb(Assembler::notEqual, L_failed);
1766 #endif
1767     __ pop(rdi); // Do pops here since jlong_arraycopy stub does not do it.
1768     __ pop(rsi);
1769     __ jump(RuntimeAddress(entry_jlong_arraycopy));
1770 
1771   __ BIND(L_failed);
1772     __ xorptr(rax, rax);
1773     __ notptr(rax); // return -1
1774     __ pop(rdi);
1775     __ pop(rsi);
1776     __ leave(); // required for proper stackwalking of RuntimeStub frame
1777     __ ret(0);
1778 
1779     // objArrayKlass
1780   __ BIND(L_objArray);
1781     // live at this point:  rcx_src_klass, src[_pos], dst[_pos]
1782 
1783     Label L_plain_copy, L_checkcast_copy;
1784     //  test array classes for subtyping
1785     __ cmpptr(rcx_src_klass, dst_klass_addr); // usual case is exact equality
1786     __ jccb(Assembler::notEqual, L_checkcast_copy);
1787 
1788     // Identically typed arrays can be copied without element-wise checks.
1789     assert_different_registers(src, src_pos, dst, dst_pos, rcx_src_klass);
1790     arraycopy_range_checks(src, src_pos, dst, dst_pos, LENGTH, L_failed);
1791 
1792   __ BIND(L_plain_copy);
1793     __ movl2ptr(count, LENGTH); // elements count
1794     __ movl2ptr(src_pos, SRC_POS);  // reload src_pos
1795     __ lea(from, Address(src, src_pos, Address::times_ptr,
1796                  arrayOopDesc::base_offset_in_bytes(T_OBJECT))); // src_addr
1797     __ movl2ptr(dst_pos, DST_POS);  // reload dst_pos
1798     __ lea(to,   Address(dst, dst_pos, Address::times_ptr,
1799                  arrayOopDesc::base_offset_in_bytes(T_OBJECT))); // dst_addr
1800     __ movptr(FROM,  from);   // src_addr
1801     __ movptr(TO,    to);     // dst_addr
1802     __ movl(COUNT, count);  // count
1803     __ jump(RuntimeAddress(entry_oop_arraycopy));
1804 
1805   __ BIND(L_checkcast_copy);
1806     // live at this point:  rcx_src_klass, dst[_pos], src[_pos]
1807     {
1808       // Handy offsets:
1809       int  ek_offset = (klassOopDesc::header_size() * HeapWordSize +
1810                         objArrayKlass::element_klass_offset_in_bytes());
1811       int sco_offset = (klassOopDesc::header_size() * HeapWordSize +
1812                         Klass::super_check_offset_offset_in_bytes());
1813 
1814       Register rsi_dst_klass = rsi;
1815       Register rdi_temp      = rdi;
1816       assert(rsi_dst_klass == src_pos, "expected alias w/ src_pos");
1817       assert(rdi_temp      == dst_pos, "expected alias w/ dst_pos");
1818       Address dst_klass_lh_addr(rsi_dst_klass, lh_offset);
1819 
1820       // Before looking at dst.length, make sure dst is also an objArray.
1821       __ movptr(rsi_dst_klass, dst_klass_addr);
1822       __ cmpl(dst_klass_lh_addr, objArray_lh);
1823       __ jccb(Assembler::notEqual, L_failed);
1824 
1825       // It is safe to examine both src.length and dst.length.
1826       __ movl2ptr(src_pos, SRC_POS);        // reload rsi
1827       arraycopy_range_checks(src, src_pos, dst, dst_pos, LENGTH, L_failed);
1828       // (Now src_pos and dst_pos are killed, but not src and dst.)
1829 
1830       // We'll need this temp (don't forget to pop it after the type check).
1831       __ push(rbx);
1832       Register rbx_src_klass = rbx;
1833 
1834       __ mov(rbx_src_klass, rcx_src_klass); // spill away from rcx
1835       __ movptr(rsi_dst_klass, dst_klass_addr);
1836       Address super_check_offset_addr(rsi_dst_klass, sco_offset);
1837       Label L_fail_array_check;
1838       generate_type_check(rbx_src_klass,
1839                           super_check_offset_addr, dst_klass_addr,
1840                           rdi_temp, NULL, &L_fail_array_check);
1841       // (On fall-through, we have passed the array type check.)
1842       __ pop(rbx);
1843       __ jmp(L_plain_copy);
1844 
1845       __ BIND(L_fail_array_check);
1846       // Reshuffle arguments so we can call checkcast_arraycopy:
1847 
1848       // match initial saves for checkcast_arraycopy
1849       // push(rsi);    // already done; see above
1850       // push(rdi);    // already done; see above
1851       // push(rbx);    // already done; see above
1852 
1853       // Marshal outgoing arguments now, freeing registers.
1854       Address   from_arg(rsp, 16+ 4);   // from
1855       Address     to_arg(rsp, 16+ 8);   // to
1856       Address length_arg(rsp, 16+12);   // elements count
1857       Address  ckoff_arg(rsp, 16+16);   // super_check_offset
1858       Address  ckval_arg(rsp, 16+20);   // super_klass
1859 
1860       Address SRC_POS_arg(rsp, 16+ 8);
1861       Address DST_POS_arg(rsp, 16+16);
1862       Address  LENGTH_arg(rsp, 16+20);
1863       // push rbx, changed the incoming offsets (why not just use rbp,??)
1864       // assert(SRC_POS_arg.disp() == SRC_POS.disp() + 4, "");
1865 
1866       __ movptr(rbx, Address(rsi_dst_klass, ek_offset));
1867       __ movl2ptr(length, LENGTH_arg);    // reload elements count
1868       __ movl2ptr(src_pos, SRC_POS_arg);  // reload src_pos
1869       __ movl2ptr(dst_pos, DST_POS_arg);  // reload dst_pos
1870 
1871       __ movptr(ckval_arg, rbx);          // destination element type
1872       __ movl(rbx, Address(rbx, sco_offset));
1873       __ movl(ckoff_arg, rbx);          // corresponding class check offset
1874 
1875       __ movl(length_arg, length);      // outgoing length argument
1876 
1877       __ lea(from, Address(src, src_pos, Address::times_ptr,
1878                             arrayOopDesc::base_offset_in_bytes(T_OBJECT)));
1879       __ movptr(from_arg, from);
1880 
1881       __ lea(to, Address(dst, dst_pos, Address::times_ptr,
1882                           arrayOopDesc::base_offset_in_bytes(T_OBJECT)));
1883       __ movptr(to_arg, to);
1884       __ jump(RuntimeAddress(entry_checkcast_arraycopy));
1885     }
1886 
1887     return start;
1888   }
1889 
1890   void generate_arraycopy_stubs() {
1891     address entry;
1892     address entry_jbyte_arraycopy;
1893     address entry_jshort_arraycopy;
1894     address entry_jint_arraycopy;
1895     address entry_oop_arraycopy;
1896     address entry_jlong_arraycopy;
1897     address entry_checkcast_arraycopy;
1898 
1899     StubRoutines::_arrayof_jbyte_disjoint_arraycopy =
1900         generate_disjoint_copy(T_BYTE,  true, Address::times_1, &entry,
1901                                "arrayof_jbyte_disjoint_arraycopy");
1902     StubRoutines::_arrayof_jbyte_arraycopy =
1903         generate_conjoint_copy(T_BYTE,  true, Address::times_1,  entry,
1904                                NULL, "arrayof_jbyte_arraycopy");
1905     StubRoutines::_jbyte_disjoint_arraycopy =
1906         generate_disjoint_copy(T_BYTE, false, Address::times_1, &entry,
1907                                "jbyte_disjoint_arraycopy");
1908     StubRoutines::_jbyte_arraycopy =
1909         generate_conjoint_copy(T_BYTE, false, Address::times_1,  entry,
1910                                &entry_jbyte_arraycopy, "jbyte_arraycopy");
1911 
1912     StubRoutines::_arrayof_jshort_disjoint_arraycopy =
1913         generate_disjoint_copy(T_SHORT,  true, Address::times_2, &entry,
1914                                "arrayof_jshort_disjoint_arraycopy");
1915     StubRoutines::_arrayof_jshort_arraycopy =
1916         generate_conjoint_copy(T_SHORT,  true, Address::times_2,  entry,
1917                                NULL, "arrayof_jshort_arraycopy");
1918     StubRoutines::_jshort_disjoint_arraycopy =
1919         generate_disjoint_copy(T_SHORT, false, Address::times_2, &entry,
1920                                "jshort_disjoint_arraycopy");
1921     StubRoutines::_jshort_arraycopy =
1922         generate_conjoint_copy(T_SHORT, false, Address::times_2,  entry,
1923                                &entry_jshort_arraycopy, "jshort_arraycopy");
1924 
1925     // Next arrays are always aligned on 4 bytes at least.
1926     StubRoutines::_jint_disjoint_arraycopy =
1927         generate_disjoint_copy(T_INT, true, Address::times_4, &entry,
1928                                "jint_disjoint_arraycopy");
1929     StubRoutines::_jint_arraycopy =
1930         generate_conjoint_copy(T_INT, true, Address::times_4,  entry,
1931                                &entry_jint_arraycopy, "jint_arraycopy");
1932 
1933     StubRoutines::_oop_disjoint_arraycopy =
1934         generate_disjoint_copy(T_OBJECT, true, Address::times_ptr, &entry,
1935                                "oop_disjoint_arraycopy");
1936     StubRoutines::_oop_arraycopy =
1937         generate_conjoint_copy(T_OBJECT, true, Address::times_ptr,  entry,
1938                                &entry_oop_arraycopy, "oop_arraycopy");
1939 
1940     StubRoutines::_jlong_disjoint_arraycopy =
1941         generate_disjoint_long_copy(&entry, "jlong_disjoint_arraycopy");
1942     StubRoutines::_jlong_arraycopy =
1943         generate_conjoint_long_copy(entry, &entry_jlong_arraycopy,
1944                                     "jlong_arraycopy");
1945 
1946     StubRoutines::_arrayof_jint_disjoint_arraycopy  =
1947         StubRoutines::_jint_disjoint_arraycopy;
1948     StubRoutines::_arrayof_oop_disjoint_arraycopy   =
1949         StubRoutines::_oop_disjoint_arraycopy;
1950     StubRoutines::_arrayof_jlong_disjoint_arraycopy =
1951         StubRoutines::_jlong_disjoint_arraycopy;
1952 
1953     StubRoutines::_arrayof_jint_arraycopy  = StubRoutines::_jint_arraycopy;
1954     StubRoutines::_arrayof_oop_arraycopy   = StubRoutines::_oop_arraycopy;
1955     StubRoutines::_arrayof_jlong_arraycopy = StubRoutines::_jlong_arraycopy;
1956 
1957     StubRoutines::_checkcast_arraycopy =
1958         generate_checkcast_copy("checkcast_arraycopy",
1959                                   &entry_checkcast_arraycopy);
1960 
1961     StubRoutines::_unsafe_arraycopy =
1962         generate_unsafe_copy("unsafe_arraycopy",
1963                                entry_jbyte_arraycopy,
1964                                entry_jshort_arraycopy,
1965                                entry_jint_arraycopy,
1966                                entry_jlong_arraycopy);
1967 
1968     StubRoutines::_generic_arraycopy =
1969         generate_generic_copy("generic_arraycopy",
1970                                entry_jbyte_arraycopy,
1971                                entry_jshort_arraycopy,
1972                                entry_jint_arraycopy,
1973                                entry_oop_arraycopy,
1974                                entry_jlong_arraycopy,
1975                                entry_checkcast_arraycopy);
1976   }
1977 
1978  public:
1979   // Information about frame layout at time of blocking runtime call.
1980   // Note that we only have to preserve callee-saved registers since
1981   // the compilers are responsible for supplying a continuation point
1982   // if they expect all registers to be preserved.
1983   enum layout {
1984     thread_off,    // last_java_sp
1985     rbp_off,       // callee saved register
1986     ret_pc,
1987     framesize
1988   };
1989 
1990  private:
1991 
1992 #undef  __
1993 #define __ masm->
1994 
1995   //------------------------------------------------------------------------------------------------------------------------
1996   // Continuation point for throwing of implicit exceptions that are not handled in
1997   // the current activation. Fabricates an exception oop and initiates normal
1998   // exception dispatching in this frame.
1999   //
2000   // Previously the compiler (c2) allowed for callee save registers on Java calls.
2001   // This is no longer true after adapter frames were removed but could possibly
2002   // be brought back in the future if the interpreter code was reworked and it
2003   // was deemed worthwhile. The comment below was left to describe what must
2004   // happen here if callee saves were resurrected. As it stands now this stub
2005   // could actually be a vanilla BufferBlob and have now oopMap at all.
2006   // Since it doesn't make much difference we've chosen to leave it the
2007   // way it was in the callee save days and keep the comment.
2008 
2009   // If we need to preserve callee-saved values we need a callee-saved oop map and
2010   // therefore have to make these stubs into RuntimeStubs rather than BufferBlobs.
2011   // If the compiler needs all registers to be preserved between the fault
2012   // point and the exception handler then it must assume responsibility for that in
2013   // AbstractCompiler::continuation_for_implicit_null_exception or
2014   // continuation_for_implicit_division_by_zero_exception. All other implicit
2015   // exceptions (e.g., NullPointerException or AbstractMethodError on entry) are
2016   // either at call sites or otherwise assume that stack unwinding will be initiated,
2017   // so caller saved registers were assumed volatile in the compiler.
2018   address generate_throw_exception(const char* name, address runtime_entry,
2019                                    bool restore_saved_exception_pc) {
2020 
2021     int insts_size = 256;
2022     int locs_size  = 32;
2023 
2024     CodeBuffer code(name, insts_size, locs_size);
2025     OopMapSet* oop_maps  = new OopMapSet();
2026     MacroAssembler* masm = new MacroAssembler(&code);
2027 
2028     address start = __ pc();
2029 
2030     // This is an inlined and slightly modified version of call_VM
2031     // which has the ability to fetch the return PC out of
2032     // thread-local storage and also sets up last_Java_sp slightly
2033     // differently than the real call_VM
2034     Register java_thread = rbx;
2035     __ get_thread(java_thread);
2036     if (restore_saved_exception_pc) {
2037       __ movptr(rax, Address(java_thread, in_bytes(JavaThread::saved_exception_pc_offset())));
2038       __ push(rax);
2039     }
2040 
2041     __ enter(); // required for proper stackwalking of RuntimeStub frame
2042 
2043     // pc and rbp, already pushed
2044     __ subptr(rsp, (framesize-2) * wordSize); // prolog
2045 
2046     // Frame is now completed as far as size and linkage.
2047 
2048     int frame_complete = __ pc() - start;
2049 
2050     // push java thread (becomes first argument of C function)
2051     __ movptr(Address(rsp, thread_off * wordSize), java_thread);
2052 
2053     // Set up last_Java_sp and last_Java_fp
2054     __ set_last_Java_frame(java_thread, rsp, rbp, NULL);
2055 
2056     // Call runtime
2057     BLOCK_COMMENT("call runtime_entry");
2058     __ call(RuntimeAddress(runtime_entry));
2059     // Generate oop map
2060     OopMap* map =  new OopMap(framesize, 0);
2061     oop_maps->add_gc_map(__ pc() - start, map);
2062 
2063     // restore the thread (cannot use the pushed argument since arguments
2064     // may be overwritten by C code generated by an optimizing compiler);
2065     // however can use the register value directly if it is callee saved.
2066     __ get_thread(java_thread);
2067 
2068     __ reset_last_Java_frame(java_thread, true, false);
2069 
2070     __ leave(); // required for proper stackwalking of RuntimeStub frame
2071 
2072     // check for pending exceptions
2073 #ifdef ASSERT
2074     Label L;
2075     __ cmpptr(Address(java_thread, Thread::pending_exception_offset()), (int32_t)NULL_WORD);
2076     __ jcc(Assembler::notEqual, L);
2077     __ should_not_reach_here();
2078     __ bind(L);
2079 #endif /* ASSERT */
2080     __ jump(RuntimeAddress(StubRoutines::forward_exception_entry()));
2081 
2082 
2083     RuntimeStub* stub = RuntimeStub::new_runtime_stub(name, &code, frame_complete, framesize, oop_maps, false);
2084     return stub->entry_point();
2085   }
2086 
2087 
2088   void create_control_words() {
2089     // Round to nearest, 53-bit mode, exceptions masked
2090     StubRoutines::_fpu_cntrl_wrd_std   = 0x027F;
2091     // Round to zero, 53-bit mode, exception mased
2092     StubRoutines::_fpu_cntrl_wrd_trunc = 0x0D7F;
2093     // Round to nearest, 24-bit mode, exceptions masked
2094     StubRoutines::_fpu_cntrl_wrd_24    = 0x007F;
2095     // Round to nearest, 64-bit mode, exceptions masked
2096     StubRoutines::_fpu_cntrl_wrd_64    = 0x037F;
2097     // Round to nearest, 64-bit mode, exceptions masked
2098     StubRoutines::_mxcsr_std           = 0x1F80;
2099     // Note: the following two constants are 80-bit values
2100     //       layout is critical for correct loading by FPU.
2101     // Bias for strict fp multiply/divide
2102     StubRoutines::_fpu_subnormal_bias1[0]= 0x00000000; // 2^(-15360) == 0x03ff 8000 0000 0000 0000
2103     StubRoutines::_fpu_subnormal_bias1[1]= 0x80000000;
2104     StubRoutines::_fpu_subnormal_bias1[2]= 0x03ff;
2105     // Un-Bias for strict fp multiply/divide
2106     StubRoutines::_fpu_subnormal_bias2[0]= 0x00000000; // 2^(+15360) == 0x7bff 8000 0000 0000 0000
2107     StubRoutines::_fpu_subnormal_bias2[1]= 0x80000000;
2108     StubRoutines::_fpu_subnormal_bias2[2]= 0x7bff;
2109   }
2110 
2111   //---------------------------------------------------------------------------
2112   // Initialization
2113 
2114   void generate_initial() {
2115     // Generates all stubs and initializes the entry points
2116 
2117     //------------------------------------------------------------------------------------------------------------------------
2118     // entry points that exist in all platforms
2119     // Note: This is code that could be shared among different platforms - however the benefit seems to be smaller than
2120     //       the disadvantage of having a much more complicated generator structure. See also comment in stubRoutines.hpp.
2121     StubRoutines::_forward_exception_entry      = generate_forward_exception();
2122 
2123     StubRoutines::_call_stub_entry              =
2124       generate_call_stub(StubRoutines::_call_stub_return_address);
2125     // is referenced by megamorphic call
2126     StubRoutines::_catch_exception_entry        = generate_catch_exception();
2127 
2128     // These are currently used by Solaris/Intel
2129     StubRoutines::_atomic_xchg_entry            = generate_atomic_xchg();
2130 
2131     StubRoutines::_handler_for_unsafe_access_entry =
2132       generate_handler_for_unsafe_access();
2133 
2134     // platform dependent
2135     create_control_words();
2136 
2137     StubRoutines::x86::_verify_mxcsr_entry                 = generate_verify_mxcsr();
2138     StubRoutines::x86::_verify_fpu_cntrl_wrd_entry         = generate_verify_fpu_cntrl_wrd();
2139     StubRoutines::_d2i_wrapper                              = generate_d2i_wrapper(T_INT,
2140                                                                                    CAST_FROM_FN_PTR(address, SharedRuntime::d2i));
2141     StubRoutines::_d2l_wrapper                              = generate_d2i_wrapper(T_LONG,
2142                                                                                    CAST_FROM_FN_PTR(address, SharedRuntime::d2l));
2143   }
2144 
2145 
2146   void generate_all() {
2147     // Generates all stubs and initializes the entry points
2148 
2149     // These entry points require SharedInfo::stack0 to be set up in non-core builds
2150     // and need to be relocatable, so they each fabricate a RuntimeStub internally.
2151     StubRoutines::_throw_AbstractMethodError_entry         = generate_throw_exception("AbstractMethodError throw_exception",          CAST_FROM_FN_PTR(address, SharedRuntime::throw_AbstractMethodError),  false);
2152     StubRoutines::_throw_IncompatibleClassChangeError_entry= generate_throw_exception("IncompatibleClassChangeError throw_exception", CAST_FROM_FN_PTR(address, SharedRuntime::throw_IncompatibleClassChangeError),  false);
2153     StubRoutines::_throw_ArithmeticException_entry         = generate_throw_exception("ArithmeticException throw_exception",          CAST_FROM_FN_PTR(address, SharedRuntime::throw_ArithmeticException),  true);
2154     StubRoutines::_throw_NullPointerException_entry        = generate_throw_exception("NullPointerException throw_exception",         CAST_FROM_FN_PTR(address, SharedRuntime::throw_NullPointerException), true);
2155     StubRoutines::_throw_NullPointerException_at_call_entry= generate_throw_exception("NullPointerException at call throw_exception", CAST_FROM_FN_PTR(address, SharedRuntime::throw_NullPointerException_at_call), false);
2156     StubRoutines::_throw_StackOverflowError_entry          = generate_throw_exception("StackOverflowError throw_exception",           CAST_FROM_FN_PTR(address, SharedRuntime::throw_StackOverflowError),   false);
2157 
2158     //------------------------------------------------------------------------------------------------------------------------
2159     // entry points that are platform specific
2160 
2161     // support for verify_oop (must happen after universe_init)
2162     StubRoutines::_verify_oop_subroutine_entry     = generate_verify_oop();
2163 
2164     // arraycopy stubs used by compilers
2165     generate_arraycopy_stubs();
2166   }
2167 
2168 
2169  public:
2170   StubGenerator(CodeBuffer* code, bool all) : StubCodeGenerator(code) {
2171     if (all) {
2172       generate_all();
2173     } else {
2174       generate_initial();
2175     }
2176   }
2177 }; // end class declaration
2178 
2179 
2180 void StubGenerator_generate(CodeBuffer* code, bool all) {
2181   StubGenerator g(code, all);
2182 }