1 /*
   2  * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2014, 2021, Red Hat Inc. All rights reserved.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  *
  24  */
  25 
  26 #include "precompiled.hpp"
  27 #include "asm/assembler.hpp"
  28 #include "c1/c1_CodeStubs.hpp"
  29 #include "c1/c1_Defs.hpp"
  30 #include "c1/c1_MacroAssembler.hpp"
  31 #include "c1/c1_Runtime1.hpp"
  32 #include "compiler/disassembler.hpp"
  33 #include "compiler/oopMap.hpp"
  34 #include "gc/shared/cardTable.hpp"
  35 #include "gc/shared/cardTableBarrierSet.hpp"
  36 #include "gc/shared/collectedHeap.hpp"
  37 #include "gc/shared/tlab_globals.hpp"
  38 #include "interpreter/interpreter.hpp"
  39 #include "memory/universe.hpp"
  40 #include "nativeInst_aarch64.hpp"
  41 #include "oops/compiledICHolder.hpp"
  42 #include "oops/oop.inline.hpp"
  43 #include "prims/jvmtiExport.hpp"
  44 #include "register_aarch64.hpp"
  45 #include "runtime/sharedRuntime.hpp"
  46 #include "runtime/signature.hpp"
  47 #include "runtime/stubRoutines.hpp"
  48 #include "runtime/vframe.hpp"
  49 #include "runtime/vframeArray.hpp"
  50 #include "utilities/powerOfTwo.hpp"
  51 #include "vmreg_aarch64.inline.hpp"
  52 
  53 
  54 // Implementation of StubAssembler
  55 
  56 int StubAssembler::call_RT(Register oop_result1, Register metadata_result, address entry, int args_size) {
  57   // setup registers
  58   assert(!(oop_result1->is_valid() || metadata_result->is_valid()) || oop_result1 != metadata_result, "registers must be different");
  59   assert(oop_result1 != rthread && metadata_result != rthread, "registers must be different");
  60   assert(args_size >= 0, "illegal args_size");
  61   bool align_stack = false;
  62 
  63   mov(c_rarg0, rthread);
  64   set_num_rt_args(0); // Nothing on stack
  65 
  66   Label retaddr;
  67   set_last_Java_frame(sp, rfp, retaddr, rscratch1);
  68 
  69   // do the call
  70   lea(rscratch1, RuntimeAddress(entry));
  71   blr(rscratch1);
  72   bind(retaddr);
  73   int call_offset = offset();
  74   // verify callee-saved register
  75 #ifdef ASSERT
  76   push(r0, sp);
  77   { Label L;
  78     get_thread(r0);
  79     cmp(rthread, r0);
  80     br(Assembler::EQ, L);
  81     stop("StubAssembler::call_RT: rthread not callee saved?");
  82     bind(L);
  83   }
  84   pop(r0, sp);
  85 #endif
  86   reset_last_Java_frame(true);
  87 
  88   // check for pending exceptions
  89   { Label L;
  90     // check for pending exceptions (java_thread is set upon return)
  91     ldr(rscratch1, Address(rthread, in_bytes(Thread::pending_exception_offset())));
  92     cbz(rscratch1, L);
  93     // exception pending => remove activation and forward to exception handler
  94     // make sure that the vm_results are cleared
  95     if (oop_result1->is_valid()) {
  96       str(zr, Address(rthread, JavaThread::vm_result_offset()));
  97     }
  98     if (metadata_result->is_valid()) {
  99       str(zr, Address(rthread, JavaThread::vm_result_2_offset()));
 100     }
 101     if (frame_size() == no_frame_size) {
 102       leave();
 103       far_jump(RuntimeAddress(StubRoutines::forward_exception_entry()));
 104     } else if (_stub_id == Runtime1::forward_exception_id) {
 105       should_not_reach_here();
 106     } else {
 107       far_jump(RuntimeAddress(Runtime1::entry_for(Runtime1::forward_exception_id)));
 108     }
 109     bind(L);
 110   }
 111   // get oop results if there are any and reset the values in the thread
 112   if (oop_result1->is_valid()) {
 113     get_vm_result(oop_result1, rthread);
 114   }
 115   if (metadata_result->is_valid()) {
 116     get_vm_result_2(metadata_result, rthread);
 117   }
 118   return call_offset;
 119 }
 120 
 121 
 122 int StubAssembler::call_RT(Register oop_result1, Register metadata_result, address entry, Register arg1) {
 123   mov(c_rarg1, arg1);
 124   return call_RT(oop_result1, metadata_result, entry, 1);
 125 }
 126 
 127 
 128 int StubAssembler::call_RT(Register oop_result1, Register metadata_result, address entry, Register arg1, Register arg2) {
 129   if (c_rarg1 == arg2) {
 130     if (c_rarg2 == arg1) {
 131       mov(rscratch1, arg1);
 132       mov(arg1, arg2);
 133       mov(arg2, rscratch1);
 134     } else {
 135       mov(c_rarg2, arg2);
 136       mov(c_rarg1, arg1);
 137     }
 138   } else {
 139     mov(c_rarg1, arg1);
 140     mov(c_rarg2, arg2);
 141   }
 142   return call_RT(oop_result1, metadata_result, entry, 2);
 143 }
 144 
 145 
 146 int StubAssembler::call_RT(Register oop_result1, Register metadata_result, address entry, Register arg1, Register arg2, Register arg3) {
 147   // if there is any conflict use the stack
 148   if (arg1 == c_rarg2 || arg1 == c_rarg3 ||
 149       arg2 == c_rarg1 || arg2 == c_rarg3 ||
 150       arg3 == c_rarg1 || arg3 == c_rarg2) {
 151     stp(arg3, arg2, Address(pre(sp, -2 * wordSize)));
 152     stp(arg1, zr, Address(pre(sp, -2 * wordSize)));
 153     ldp(c_rarg1, zr, Address(post(sp, 2 * wordSize)));
 154     ldp(c_rarg3, c_rarg2, Address(post(sp, 2 * wordSize)));
 155   } else {
 156     mov(c_rarg1, arg1);
 157     mov(c_rarg2, arg2);
 158     mov(c_rarg3, arg3);
 159   }
 160   return call_RT(oop_result1, metadata_result, entry, 3);
 161 }
 162 
 163 enum return_state_t {
 164   does_not_return, requires_return
 165 };
 166 
 167 
 168 // Implementation of StubFrame
 169 
 170 class StubFrame: public StackObj {
 171  private:
 172   StubAssembler* _sasm;
 173   bool _return_state;
 174 
 175  public:
 176   StubFrame(StubAssembler* sasm, const char* name, bool must_gc_arguments, return_state_t return_state=requires_return);
 177   void load_argument(int offset_in_words, Register reg);
 178 
 179   ~StubFrame();
 180 };;
 181 
 182 void StubAssembler::prologue(const char* name, bool must_gc_arguments) {
 183   set_info(name, must_gc_arguments);
 184   enter();
 185 }
 186 
 187 void StubAssembler::epilogue() {
 188   leave();
 189   ret(lr);
 190 }
 191 
 192 #define __ _sasm->
 193 
 194 StubFrame::StubFrame(StubAssembler* sasm, const char* name, bool must_gc_arguments, return_state_t return_state) {
 195   _sasm = sasm;
 196   _return_state = return_state;
 197   __ prologue(name, must_gc_arguments);
 198 }
 199 
 200 // load parameters that were stored with LIR_Assembler::store_parameter
 201 // Note: offsets for store_parameter and load_argument must match
 202 void StubFrame::load_argument(int offset_in_words, Register reg) {
 203   __ load_parameter(offset_in_words, reg);
 204 }
 205 
 206 StubFrame::~StubFrame() {
 207   if (_return_state == requires_return) {
 208     __ epilogue();
 209   } else {
 210     __ should_not_reach_here();
 211   }
 212 }
 213 
 214 #undef __
 215 
 216 
 217 // Implementation of Runtime1
 218 
 219 #define __ sasm->
 220 
 221 const int float_regs_as_doubles_size_in_slots = pd_nof_fpu_regs_frame_map * 2;
 222 
 223 // Stack layout for saving/restoring  all the registers needed during a runtime
 224 // call (this includes deoptimization)
 225 // Note: note that users of this frame may well have arguments to some runtime
 226 // while these values are on the stack. These positions neglect those arguments
 227 // but the code in save_live_registers will take the argument count into
 228 // account.
 229 //
 230 
 231 enum reg_save_layout {
 232   reg_save_frame_size = 32 /* float */ + 32 /* integer */
 233 };
 234 
 235 // Save off registers which might be killed by calls into the runtime.
 236 // Tries to smart of about FP registers.  In particular we separate
 237 // saving and describing the FPU registers for deoptimization since we
 238 // have to save the FPU registers twice if we describe them.  The
 239 // deopt blob is the only thing which needs to describe FPU registers.
 240 // In all other cases it should be sufficient to simply save their
 241 // current value.
 242 
 243 static int cpu_reg_save_offsets[FrameMap::nof_cpu_regs];
 244 static int fpu_reg_save_offsets[FrameMap::nof_fpu_regs];
 245 static int reg_save_size_in_words;
 246 static int frame_size_in_bytes = -1;
 247 
 248 static OopMap* generate_oop_map(StubAssembler* sasm, bool save_fpu_registers) {
 249   int frame_size_in_bytes = reg_save_frame_size * BytesPerWord;
 250   sasm->set_frame_size(frame_size_in_bytes / BytesPerWord);
 251   int frame_size_in_slots = frame_size_in_bytes / sizeof(jint);
 252   OopMap* oop_map = new OopMap(frame_size_in_slots, 0);
 253 
 254   for (int i = 0; i < FrameMap::nof_cpu_regs; i++) {
 255     Register r = as_Register(i);
 256     if (i <= 18 && i != rscratch1->encoding() && i != rscratch2->encoding()) {
 257       int sp_offset = cpu_reg_save_offsets[i];
 258       oop_map->set_callee_saved(VMRegImpl::stack2reg(sp_offset),
 259                                 r->as_VMReg());
 260     }
 261   }
 262 
 263   if (save_fpu_registers) {
 264     for (int i = 0; i < FrameMap::nof_fpu_regs; i++) {
 265       FloatRegister r = as_FloatRegister(i);
 266       {
 267         int sp_offset = fpu_reg_save_offsets[i];
 268         oop_map->set_callee_saved(VMRegImpl::stack2reg(sp_offset),
 269                                   r->as_VMReg());
 270       }
 271     }
 272   }
 273   return oop_map;
 274 }
 275 
 276 static OopMap* save_live_registers(StubAssembler* sasm,
 277                                    bool save_fpu_registers = true) {
 278   __ block_comment("save_live_registers");
 279 
 280   __ push(RegSet::range(r0, r29), sp);         // integer registers except lr & sp
 281 
 282   if (save_fpu_registers) {
 283     for (int i = 31; i>= 0; i -= 4) {
 284       __ sub(sp, sp, 4 * wordSize); // no pre-increment for st1. Emulate it without modifying other registers
 285       __ st1(as_FloatRegister(i-3), as_FloatRegister(i-2), as_FloatRegister(i-1),
 286           as_FloatRegister(i), __ T1D, Address(sp));
 287     }
 288   } else {
 289     __ add(sp, sp, -32 * wordSize);
 290   }
 291 
 292   return generate_oop_map(sasm, save_fpu_registers);
 293 }
 294 
 295 static void restore_live_registers(StubAssembler* sasm, bool restore_fpu_registers = true) {
 296   if (restore_fpu_registers) {
 297     for (int i = 0; i < 32; i += 4)
 298       __ ld1(as_FloatRegister(i), as_FloatRegister(i+1), as_FloatRegister(i+2),
 299           as_FloatRegister(i+3), __ T1D, Address(__ post(sp, 4 * wordSize)));
 300   } else {
 301     __ add(sp, sp, 32 * wordSize);
 302   }
 303 
 304   __ pop(RegSet::range(r0, r29), sp);
 305 }
 306 
 307 static void restore_live_registers_except_r0(StubAssembler* sasm, bool restore_fpu_registers = true)  {
 308 
 309   if (restore_fpu_registers) {
 310     for (int i = 0; i < 32; i += 4)
 311       __ ld1(as_FloatRegister(i), as_FloatRegister(i+1), as_FloatRegister(i+2),
 312           as_FloatRegister(i+3), __ T1D, Address(__ post(sp, 4 * wordSize)));
 313   } else {
 314     __ add(sp, sp, 32 * wordSize);
 315   }
 316 
 317   __ ldp(zr, r1, Address(__ post(sp, 16)));
 318   __ pop(RegSet::range(r2, r29), sp);
 319 }
 320 
 321 
 322 
 323 void Runtime1::initialize_pd() {
 324   int i;
 325   int sp_offset = 0;
 326 
 327   // all float registers are saved explicitly
 328   assert(FrameMap::nof_fpu_regs == 32, "double registers not handled here");
 329   for (i = 0; i < FrameMap::nof_fpu_regs; i++) {
 330     fpu_reg_save_offsets[i] = sp_offset;
 331     sp_offset += 2;   // SP offsets are in halfwords
 332   }
 333 
 334   for (i = 0; i < FrameMap::nof_cpu_regs; i++) {
 335     Register r = as_Register(i);
 336     cpu_reg_save_offsets[i] = sp_offset;
 337     sp_offset += 2;   // SP offsets are in halfwords
 338   }
 339 }
 340 
 341 
 342 // target: the entry point of the method that creates and posts the exception oop
 343 // has_argument: true if the exception needs arguments (passed in rscratch1 and rscratch2)
 344 
 345 OopMapSet* Runtime1::generate_exception_throw(StubAssembler* sasm, address target, bool has_argument) {
 346   // make a frame and preserve the caller's caller-save registers
 347   OopMap* oop_map = save_live_registers(sasm);
 348   int call_offset;
 349   if (!has_argument) {
 350     call_offset = __ call_RT(noreg, noreg, target);
 351   } else {
 352     __ mov(c_rarg1, rscratch1);
 353     __ mov(c_rarg2, rscratch2);
 354     call_offset = __ call_RT(noreg, noreg, target);
 355   }
 356   OopMapSet* oop_maps = new OopMapSet();
 357   oop_maps->add_gc_map(call_offset, oop_map);
 358   return oop_maps;
 359 }
 360 
 361 
 362 OopMapSet* Runtime1::generate_handle_exception(StubID id, StubAssembler *sasm) {
 363   __ block_comment("generate_handle_exception");
 364 
 365   // incoming parameters
 366   const Register exception_oop = r0;
 367   const Register exception_pc  = r3;
 368   // other registers used in this stub
 369 
 370   // Save registers, if required.
 371   OopMapSet* oop_maps = new OopMapSet();
 372   OopMap* oop_map = nullptr;
 373   switch (id) {
 374   case forward_exception_id:
 375     // We're handling an exception in the context of a compiled frame.
 376     // The registers have been saved in the standard places.  Perform
 377     // an exception lookup in the caller and dispatch to the handler
 378     // if found.  Otherwise unwind and dispatch to the callers
 379     // exception handler.
 380     oop_map = generate_oop_map(sasm, 1 /*thread*/);
 381 
 382     // load and clear pending exception oop into r0
 383     __ ldr(exception_oop, Address(rthread, Thread::pending_exception_offset()));
 384     __ str(zr, Address(rthread, Thread::pending_exception_offset()));
 385 
 386     // load issuing PC (the return address for this stub) into r3
 387     __ ldr(exception_pc, Address(rfp, 1*BytesPerWord));
 388     __ authenticate_return_address(exception_pc);
 389 
 390     // make sure that the vm_results are cleared (may be unnecessary)
 391     __ str(zr, Address(rthread, JavaThread::vm_result_offset()));
 392     __ str(zr, Address(rthread, JavaThread::vm_result_2_offset()));
 393     break;
 394   case handle_exception_nofpu_id:
 395   case handle_exception_id:
 396     // At this point all registers MAY be live.
 397     oop_map = save_live_registers(sasm, id != handle_exception_nofpu_id);
 398     break;
 399   case handle_exception_from_callee_id: {
 400     // At this point all registers except exception oop (r0) and
 401     // exception pc (lr) are dead.
 402     const int frame_size = 2 /*fp, return address*/;
 403     oop_map = new OopMap(frame_size * VMRegImpl::slots_per_word, 0);
 404     sasm->set_frame_size(frame_size);
 405     break;
 406   }
 407   default: ShouldNotReachHere();
 408   }
 409 
 410   // verify that only r0 and r3 are valid at this time
 411   __ invalidate_registers(false, true, true, false, true, true);
 412   // verify that r0 contains a valid exception
 413   __ verify_not_null_oop(exception_oop);
 414 
 415 #ifdef ASSERT
 416   // check that fields in JavaThread for exception oop and issuing pc are
 417   // empty before writing to them
 418   Label oop_empty;
 419   __ ldr(rscratch1, Address(rthread, JavaThread::exception_oop_offset()));
 420   __ cbz(rscratch1, oop_empty);
 421   __ stop("exception oop already set");
 422   __ bind(oop_empty);
 423 
 424   Label pc_empty;
 425   __ ldr(rscratch1, Address(rthread, JavaThread::exception_pc_offset()));
 426   __ cbz(rscratch1, pc_empty);
 427   __ stop("exception pc already set");
 428   __ bind(pc_empty);
 429 #endif
 430 
 431   // save exception oop and issuing pc into JavaThread
 432   // (exception handler will load it from here)
 433   __ str(exception_oop, Address(rthread, JavaThread::exception_oop_offset()));
 434   __ str(exception_pc, Address(rthread, JavaThread::exception_pc_offset()));
 435 
 436   // patch throwing pc into return address (has bci & oop map)
 437   __ protect_return_address(exception_pc);
 438   __ str(exception_pc, Address(rfp, 1*BytesPerWord));
 439 
 440   // compute the exception handler.
 441   // the exception oop and the throwing pc are read from the fields in JavaThread
 442   int call_offset = __ call_RT(noreg, noreg, CAST_FROM_FN_PTR(address, exception_handler_for_pc));
 443   oop_maps->add_gc_map(call_offset, oop_map);
 444 
 445   // r0: handler address
 446   //      will be the deopt blob if nmethod was deoptimized while we looked up
 447   //      handler regardless of whether handler existed in the nmethod.
 448 
 449   // only r0 is valid at this time, all other registers have been destroyed by the runtime call
 450   __ invalidate_registers(false, true, true, true, true, true);
 451 
 452   // patch the return address, this stub will directly return to the exception handler
 453   __ protect_return_address(r0);
 454   __ str(r0, Address(rfp, 1*BytesPerWord));
 455 
 456   switch (id) {
 457   case forward_exception_id:
 458   case handle_exception_nofpu_id:
 459   case handle_exception_id:
 460     // Restore the registers that were saved at the beginning.
 461     restore_live_registers(sasm, id != handle_exception_nofpu_id);
 462     break;
 463   case handle_exception_from_callee_id:
 464     break;
 465   default:  ShouldNotReachHere();
 466   }
 467 
 468   return oop_maps;
 469 }
 470 
 471 
 472 void Runtime1::generate_unwind_exception(StubAssembler *sasm) {
 473   // incoming parameters
 474   const Register exception_oop = r0;
 475   // callee-saved copy of exception_oop during runtime call
 476   const Register exception_oop_callee_saved = r19;
 477   // other registers used in this stub
 478   const Register exception_pc = r3;
 479   const Register handler_addr = r1;
 480 
 481   if (AbortVMOnException) {
 482     __ mov(rscratch1, exception_oop);
 483     __ enter();
 484     save_live_registers(sasm);
 485     __ call_VM_leaf(CAST_FROM_FN_PTR(address, check_abort_on_vm_exception), rscratch1);
 486     restore_live_registers(sasm);
 487     __ leave();
 488   }
 489 
 490   // verify that only r0, is valid at this time
 491   __ invalidate_registers(false, true, true, true, true, true);
 492 
 493 #ifdef ASSERT
 494   // check that fields in JavaThread for exception oop and issuing pc are empty
 495   Label oop_empty;
 496   __ ldr(rscratch1, Address(rthread, JavaThread::exception_oop_offset()));
 497   __ cbz(rscratch1, oop_empty);
 498   __ stop("exception oop must be empty");
 499   __ bind(oop_empty);
 500 
 501   Label pc_empty;
 502   __ ldr(rscratch1, Address(rthread, JavaThread::exception_pc_offset()));
 503   __ cbz(rscratch1, pc_empty);
 504   __ stop("exception pc must be empty");
 505   __ bind(pc_empty);
 506 #endif
 507 
 508   // Save our return address because
 509   // exception_handler_for_return_address will destroy it.  We also
 510   // save exception_oop
 511   __ mov(r3, lr);
 512   __ protect_return_address();
 513   __ stp(lr, exception_oop, Address(__ pre(sp, -2 * wordSize)));
 514 
 515   // search the exception handler address of the caller (using the return address)
 516   __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::exception_handler_for_return_address), rthread, r3);
 517   // r0: exception handler address of the caller
 518 
 519   // Only R0 is valid at this time; all other registers have been
 520   // destroyed by the call.
 521   __ invalidate_registers(false, true, true, true, false, true);
 522 
 523   // move result of call into correct register
 524   __ mov(handler_addr, r0);
 525 
 526   // get throwing pc (= return address).
 527   // lr has been destroyed by the call
 528   __ ldp(lr, exception_oop, Address(__ post(sp, 2 * wordSize)));
 529   __ authenticate_return_address();
 530   __ mov(r3, lr);
 531 
 532   __ verify_not_null_oop(exception_oop);
 533 
 534   // continue at exception handler (return address removed)
 535   // note: do *not* remove arguments when unwinding the
 536   //       activation since the caller assumes having
 537   //       all arguments on the stack when entering the
 538   //       runtime to determine the exception handler
 539   //       (GC happens at call site with arguments!)
 540   // r0: exception oop
 541   // r3: throwing pc
 542   // r1: exception handler
 543   __ br(handler_addr);
 544 }
 545 
 546 
 547 
 548 OopMapSet* Runtime1::generate_patching(StubAssembler* sasm, address target) {
 549   // use the maximum number of runtime-arguments here because it is difficult to
 550   // distinguish each RT-Call.
 551   // Note: This number affects also the RT-Call in generate_handle_exception because
 552   //       the oop-map is shared for all calls.
 553   DeoptimizationBlob* deopt_blob = SharedRuntime::deopt_blob();
 554   assert(deopt_blob != nullptr, "deoptimization blob must have been created");
 555 
 556   OopMap* oop_map = save_live_registers(sasm);
 557 
 558   __ mov(c_rarg0, rthread);
 559   Label retaddr;
 560   __ set_last_Java_frame(sp, rfp, retaddr, rscratch1);
 561   // do the call
 562   __ lea(rscratch1, RuntimeAddress(target));
 563   __ blr(rscratch1);
 564   __ bind(retaddr);
 565   OopMapSet* oop_maps = new OopMapSet();
 566   oop_maps->add_gc_map(__ offset(), oop_map);
 567   // verify callee-saved register
 568 #ifdef ASSERT
 569   { Label L;
 570     __ get_thread(rscratch1);
 571     __ cmp(rthread, rscratch1);
 572     __ br(Assembler::EQ, L);
 573     __ stop("StubAssembler::call_RT: rthread not callee saved?");
 574     __ bind(L);
 575   }
 576 #endif
 577 
 578   __ reset_last_Java_frame(true);
 579 
 580 #ifdef ASSERT
 581   // check that fields in JavaThread for exception oop and issuing pc are empty
 582   Label oop_empty;
 583   __ ldr(rscratch1, Address(rthread, Thread::pending_exception_offset()));
 584   __ cbz(rscratch1, oop_empty);
 585   __ stop("exception oop must be empty");
 586   __ bind(oop_empty);
 587 
 588   Label pc_empty;
 589   __ ldr(rscratch1, Address(rthread, JavaThread::exception_pc_offset()));
 590   __ cbz(rscratch1, pc_empty);
 591   __ stop("exception pc must be empty");
 592   __ bind(pc_empty);
 593 #endif
 594 
 595   // Runtime will return true if the nmethod has been deoptimized, this is the
 596   // expected scenario and anything else is  an error. Note that we maintain a
 597   // check on the result purely as a defensive measure.
 598   Label no_deopt;
 599   __ cbz(r0, no_deopt);                                // Have we deoptimized?
 600 
 601   // Perform a re-execute. The proper return  address is already on the stack,
 602   // we just need  to restore registers, pop  all of our frame  but the return
 603   // address and jump to the deopt blob.
 604   restore_live_registers(sasm);
 605   __ leave();
 606   __ far_jump(RuntimeAddress(deopt_blob->unpack_with_reexecution()));
 607 
 608   __ bind(no_deopt);
 609   __ stop("deopt not performed");
 610 
 611   return oop_maps;
 612 }
 613 
 614 
 615 OopMapSet* Runtime1::generate_code_for(StubID id, StubAssembler* sasm) {
 616 
 617   const Register exception_oop = r0;
 618   const Register exception_pc  = r3;
 619 
 620   // for better readability
 621   const bool must_gc_arguments = true;
 622   const bool dont_gc_arguments = false;
 623 
 624   // default value; overwritten for some optimized stubs that are called from methods that do not use the fpu
 625   bool save_fpu_registers = true;
 626 
 627   // stub code & info for the different stubs
 628   OopMapSet* oop_maps = nullptr;
 629   OopMap* oop_map = nullptr;
 630   switch (id) {
 631     {
 632     case forward_exception_id:
 633       {
 634         oop_maps = generate_handle_exception(id, sasm);
 635         __ leave();
 636         __ ret(lr);
 637       }
 638       break;
 639 
 640     case throw_div0_exception_id:
 641       { StubFrame f(sasm, "throw_div0_exception", dont_gc_arguments, does_not_return);
 642         oop_maps = generate_exception_throw(sasm, CAST_FROM_FN_PTR(address, throw_div0_exception), false);
 643       }
 644       break;
 645 
 646     case throw_null_pointer_exception_id:
 647       { StubFrame f(sasm, "throw_null_pointer_exception", dont_gc_arguments, does_not_return);
 648         oop_maps = generate_exception_throw(sasm, CAST_FROM_FN_PTR(address, throw_null_pointer_exception), false);
 649       }
 650       break;
 651 
 652     case new_instance_id:
 653     case fast_new_instance_id:
 654     case fast_new_instance_init_check_id:
 655       {
 656         Register klass = r3; // Incoming
 657         Register obj   = r0; // Result
 658 
 659         if (id == new_instance_id) {
 660           __ set_info("new_instance", dont_gc_arguments);
 661         } else if (id == fast_new_instance_id) {
 662           __ set_info("fast new_instance", dont_gc_arguments);
 663         } else {
 664           assert(id == fast_new_instance_init_check_id, "bad StubID");
 665           __ set_info("fast new_instance init check", dont_gc_arguments);
 666         }
 667 
 668         __ enter();
 669         OopMap* map = save_live_registers(sasm);
 670         int call_offset = __ call_RT(obj, noreg, CAST_FROM_FN_PTR(address, new_instance), klass);
 671         oop_maps = new OopMapSet();
 672         oop_maps->add_gc_map(call_offset, map);
 673         restore_live_registers_except_r0(sasm);
 674         __ verify_oop(obj);
 675         __ leave();
 676         __ ret(lr);
 677 
 678         // r0,: new instance
 679       }
 680 
 681       break;
 682 
 683     case counter_overflow_id:
 684       {
 685         Register bci = r0, method = r1;
 686         __ enter();
 687         OopMap* map = save_live_registers(sasm);
 688         // Retrieve bci
 689         __ ldrw(bci, Address(rfp, 2*BytesPerWord));
 690         // And a pointer to the Method*
 691         __ ldr(method, Address(rfp, 3*BytesPerWord));
 692         int call_offset = __ call_RT(noreg, noreg, CAST_FROM_FN_PTR(address, counter_overflow), bci, method);
 693         oop_maps = new OopMapSet();
 694         oop_maps->add_gc_map(call_offset, map);
 695         restore_live_registers(sasm);
 696         __ leave();
 697         __ ret(lr);
 698       }
 699       break;
 700 
 701     case new_type_array_id:
 702     case new_object_array_id:
 703       {
 704         Register length   = r19; // Incoming
 705         Register klass    = r3; // Incoming
 706         Register obj      = r0; // Result
 707 
 708         if (id == new_type_array_id) {
 709           __ set_info("new_type_array", dont_gc_arguments);
 710         } else {
 711           __ set_info("new_object_array", dont_gc_arguments);
 712         }
 713 
 714 #ifdef ASSERT
 715         // assert object type is really an array of the proper kind
 716         {
 717           Label ok;
 718           Register t0 = obj;
 719           __ ldrw(t0, Address(klass, Klass::layout_helper_offset()));
 720           __ asrw(t0, t0, Klass::_lh_array_tag_shift);
 721           int tag = ((id == new_type_array_id)
 722                      ? Klass::_lh_array_tag_type_value
 723                      : Klass::_lh_array_tag_obj_value);
 724           __ mov(rscratch1, tag);
 725           __ cmpw(t0, rscratch1);
 726           __ br(Assembler::EQ, ok);
 727           __ stop("assert(is an array klass)");
 728           __ should_not_reach_here();
 729           __ bind(ok);
 730         }
 731 #endif // ASSERT
 732 
 733         __ enter();
 734         OopMap* map = save_live_registers(sasm);
 735         int call_offset;
 736         if (id == new_type_array_id) {
 737           call_offset = __ call_RT(obj, noreg, CAST_FROM_FN_PTR(address, new_type_array), klass, length);
 738         } else {
 739           call_offset = __ call_RT(obj, noreg, CAST_FROM_FN_PTR(address, new_object_array), klass, length);
 740         }
 741 
 742         oop_maps = new OopMapSet();
 743         oop_maps->add_gc_map(call_offset, map);
 744         restore_live_registers_except_r0(sasm);
 745 
 746         __ verify_oop(obj);
 747         __ leave();
 748         __ ret(lr);
 749 
 750         // r0: new array
 751       }
 752       break;
 753 
 754     case new_multi_array_id:
 755       { StubFrame f(sasm, "new_multi_array", dont_gc_arguments);
 756         // r0,: klass
 757         // r19,: rank
 758         // r2: address of 1st dimension
 759         OopMap* map = save_live_registers(sasm);
 760         __ mov(c_rarg1, r0);
 761         __ mov(c_rarg3, r2);
 762         __ mov(c_rarg2, r19);
 763         int call_offset = __ call_RT(r0, noreg, CAST_FROM_FN_PTR(address, new_multi_array), r1, r2, r3);
 764 
 765         oop_maps = new OopMapSet();
 766         oop_maps->add_gc_map(call_offset, map);
 767         restore_live_registers_except_r0(sasm);
 768 
 769         // r0,: new multi array
 770         __ verify_oop(r0);
 771       }
 772       break;
 773 
 774     case register_finalizer_id:
 775       {
 776         __ set_info("register_finalizer", dont_gc_arguments);
 777 
 778         // This is called via call_runtime so the arguments
 779         // will be place in C abi locations
 780 
 781         __ verify_oop(c_rarg0);
 782 
 783         // load the klass and check the has finalizer flag
 784         Label register_finalizer;
 785         Register t = r5;
 786         __ load_klass(t, r0);
 787         __ ldrw(t, Address(t, Klass::access_flags_offset()));
 788         __ tbnz(t, exact_log2(JVM_ACC_HAS_FINALIZER), register_finalizer);
 789         __ ret(lr);
 790 
 791         __ bind(register_finalizer);
 792         __ enter();
 793         OopMap* oop_map = save_live_registers(sasm);
 794         int call_offset = __ call_RT(noreg, noreg, CAST_FROM_FN_PTR(address, SharedRuntime::register_finalizer), r0);
 795         oop_maps = new OopMapSet();
 796         oop_maps->add_gc_map(call_offset, oop_map);
 797 
 798         // Now restore all the live registers
 799         restore_live_registers(sasm);
 800 
 801         __ leave();
 802         __ ret(lr);
 803       }
 804       break;
 805 
 806     case throw_class_cast_exception_id:
 807       { StubFrame f(sasm, "throw_class_cast_exception", dont_gc_arguments, does_not_return);
 808         oop_maps = generate_exception_throw(sasm, CAST_FROM_FN_PTR(address, throw_class_cast_exception), true);
 809       }
 810       break;
 811 
 812     case throw_incompatible_class_change_error_id:
 813       { StubFrame f(sasm, "throw_incompatible_class_cast_exception", dont_gc_arguments, does_not_return);
 814         oop_maps = generate_exception_throw(sasm, CAST_FROM_FN_PTR(address, throw_incompatible_class_change_error), false);
 815       }
 816       break;
 817 
 818     case slow_subtype_check_id:
 819       {
 820         // Typical calling sequence:
 821         // __ push(klass_RInfo);  // object klass or other subclass
 822         // __ push(sup_k_RInfo);  // array element klass or other superclass
 823         // __ bl(slow_subtype_check);
 824         // Note that the subclass is pushed first, and is therefore deepest.
 825         enum layout {
 826           r0_off, r0_off_hi,
 827           r2_off, r2_off_hi,
 828           r4_off, r4_off_hi,
 829           r5_off, r5_off_hi,
 830           sup_k_off, sup_k_off_hi,
 831           klass_off, klass_off_hi,
 832           framesize,
 833           result_off = sup_k_off
 834         };
 835 
 836         __ set_info("slow_subtype_check", dont_gc_arguments);
 837         __ push(RegSet::of(r0, r2, r4, r5), sp);
 838 
 839         // This is called by pushing args and not with C abi
 840         // __ ldr(r4, Address(sp, (klass_off) * VMRegImpl::stack_slot_size)); // subclass
 841         // __ ldr(r0, Address(sp, (sup_k_off) * VMRegImpl::stack_slot_size)); // superclass
 842 
 843         __ ldp(r4, r0, Address(sp, (sup_k_off) * VMRegImpl::stack_slot_size));
 844 
 845         Label miss;
 846         __ check_klass_subtype_slow_path(r4, r0, r2, r5, nullptr, &miss);
 847 
 848         // fallthrough on success:
 849         __ mov(rscratch1, 1);
 850         __ str(rscratch1, Address(sp, (result_off) * VMRegImpl::stack_slot_size)); // result
 851         __ pop(RegSet::of(r0, r2, r4, r5), sp);
 852         __ ret(lr);
 853 
 854         __ bind(miss);
 855         __ str(zr, Address(sp, (result_off) * VMRegImpl::stack_slot_size)); // result
 856         __ pop(RegSet::of(r0, r2, r4, r5), sp);
 857         __ ret(lr);
 858       }
 859       break;
 860 
 861     case monitorenter_nofpu_id:
 862       save_fpu_registers = false;
 863       // fall through
 864     case monitorenter_id:
 865       {
 866         StubFrame f(sasm, "monitorenter", dont_gc_arguments);
 867         OopMap* map = save_live_registers(sasm, save_fpu_registers);
 868 
 869         // Called with store_parameter and not C abi
 870 
 871         f.load_argument(1, r0); // r0,: object
 872         f.load_argument(0, r1); // r1,: lock address
 873 
 874         int call_offset = __ call_RT(noreg, noreg, CAST_FROM_FN_PTR(address, monitorenter), r0, r1);
 875 
 876         oop_maps = new OopMapSet();
 877         oop_maps->add_gc_map(call_offset, map);
 878         restore_live_registers(sasm, save_fpu_registers);
 879       }
 880       break;
 881 
 882     case monitorexit_nofpu_id:
 883       save_fpu_registers = false;
 884       // fall through
 885     case monitorexit_id:
 886       {
 887         StubFrame f(sasm, "monitorexit", dont_gc_arguments);
 888         OopMap* map = save_live_registers(sasm, save_fpu_registers);
 889 
 890         // Called with store_parameter and not C abi
 891 
 892         f.load_argument(0, r0); // r0,: lock address
 893 
 894         // note: really a leaf routine but must setup last java sp
 895         //       => use call_RT for now (speed can be improved by
 896         //       doing last java sp setup manually)
 897         int call_offset = __ call_RT(noreg, noreg, CAST_FROM_FN_PTR(address, monitorexit), r0);
 898 
 899         oop_maps = new OopMapSet();
 900         oop_maps->add_gc_map(call_offset, map);
 901         restore_live_registers(sasm, save_fpu_registers);
 902       }
 903       break;
 904 
 905     case deoptimize_id:
 906       {
 907         StubFrame f(sasm, "deoptimize", dont_gc_arguments, does_not_return);
 908         OopMap* oop_map = save_live_registers(sasm);
 909         f.load_argument(0, c_rarg1);
 910         int call_offset = __ call_RT(noreg, noreg, CAST_FROM_FN_PTR(address, deoptimize), c_rarg1);
 911 
 912         oop_maps = new OopMapSet();
 913         oop_maps->add_gc_map(call_offset, oop_map);
 914         restore_live_registers(sasm);
 915         DeoptimizationBlob* deopt_blob = SharedRuntime::deopt_blob();
 916         assert(deopt_blob != nullptr, "deoptimization blob must have been created");
 917         __ leave();
 918         __ far_jump(RuntimeAddress(deopt_blob->unpack_with_reexecution()));
 919       }
 920       break;
 921 
 922     case throw_range_check_failed_id:
 923       { StubFrame f(sasm, "range_check_failed", dont_gc_arguments, does_not_return);
 924         oop_maps = generate_exception_throw(sasm, CAST_FROM_FN_PTR(address, throw_range_check_exception), true);
 925       }
 926       break;
 927 
 928     case unwind_exception_id:
 929       { __ set_info("unwind_exception", dont_gc_arguments);
 930         // note: no stubframe since we are about to leave the current
 931         //       activation and we are calling a leaf VM function only.
 932         generate_unwind_exception(sasm);
 933       }
 934       break;
 935 
 936     case access_field_patching_id:
 937       { StubFrame f(sasm, "access_field_patching", dont_gc_arguments, does_not_return);
 938         // we should set up register map
 939         oop_maps = generate_patching(sasm, CAST_FROM_FN_PTR(address, access_field_patching));
 940       }
 941       break;
 942 
 943     case load_klass_patching_id:
 944       { StubFrame f(sasm, "load_klass_patching", dont_gc_arguments, does_not_return);
 945         // we should set up register map
 946         oop_maps = generate_patching(sasm, CAST_FROM_FN_PTR(address, move_klass_patching));
 947       }
 948       break;
 949 
 950     case load_mirror_patching_id:
 951       { StubFrame f(sasm, "load_mirror_patching", dont_gc_arguments, does_not_return);
 952         // we should set up register map
 953         oop_maps = generate_patching(sasm, CAST_FROM_FN_PTR(address, move_mirror_patching));
 954       }
 955       break;
 956 
 957     case load_appendix_patching_id:
 958       { StubFrame f(sasm, "load_appendix_patching", dont_gc_arguments, does_not_return);
 959         // we should set up register map
 960         oop_maps = generate_patching(sasm, CAST_FROM_FN_PTR(address, move_appendix_patching));
 961       }
 962       break;
 963 
 964     case handle_exception_nofpu_id:
 965     case handle_exception_id:
 966       { StubFrame f(sasm, "handle_exception", dont_gc_arguments);
 967         oop_maps = generate_handle_exception(id, sasm);
 968       }
 969       break;
 970 
 971     case handle_exception_from_callee_id:
 972       { StubFrame f(sasm, "handle_exception_from_callee", dont_gc_arguments);
 973         oop_maps = generate_handle_exception(id, sasm);
 974       }
 975       break;
 976 
 977     case throw_index_exception_id:
 978       { StubFrame f(sasm, "index_range_check_failed", dont_gc_arguments, does_not_return);
 979         oop_maps = generate_exception_throw(sasm, CAST_FROM_FN_PTR(address, throw_index_exception), true);
 980       }
 981       break;
 982 
 983     case throw_array_store_exception_id:
 984       { StubFrame f(sasm, "throw_array_store_exception", dont_gc_arguments, does_not_return);
 985         // tos + 0: link
 986         //     + 1: return address
 987         oop_maps = generate_exception_throw(sasm, CAST_FROM_FN_PTR(address, throw_array_store_exception), true);
 988       }
 989       break;
 990 
 991     case predicate_failed_trap_id:
 992       {
 993         StubFrame f(sasm, "predicate_failed_trap", dont_gc_arguments, does_not_return);
 994 
 995         OopMap* map = save_live_registers(sasm);
 996 
 997         int call_offset = __ call_RT(noreg, noreg, CAST_FROM_FN_PTR(address, predicate_failed_trap));
 998         oop_maps = new OopMapSet();
 999         oop_maps->add_gc_map(call_offset, map);
1000         restore_live_registers(sasm);
1001         __ leave();
1002         DeoptimizationBlob* deopt_blob = SharedRuntime::deopt_blob();
1003         assert(deopt_blob != nullptr, "deoptimization blob must have been created");
1004 
1005         __ far_jump(RuntimeAddress(deopt_blob->unpack_with_reexecution()));
1006       }
1007       break;
1008 
1009     case dtrace_object_alloc_id:
1010       { // c_rarg0: object
1011         StubFrame f(sasm, "dtrace_object_alloc", dont_gc_arguments);
1012         save_live_registers(sasm);
1013 
1014         __ call_VM_leaf(CAST_FROM_FN_PTR(address, static_cast<int (*)(oopDesc*)>(SharedRuntime::dtrace_object_alloc)), c_rarg0);
1015 
1016         restore_live_registers(sasm);
1017       }
1018       break;
1019 
1020     default:
1021       { StubFrame f(sasm, "unimplemented entry", dont_gc_arguments, does_not_return);
1022         __ mov(r0, (int)id);
1023         __ call_RT(noreg, noreg, CAST_FROM_FN_PTR(address, unimplemented_entry), r0);
1024       }
1025       break;
1026     }
1027   }
1028   return oop_maps;
1029 }
1030 
1031 #undef __
1032 
1033 const char *Runtime1::pd_name_for_address(address entry) { Unimplemented(); return 0; }