1 /*
   2  * Copyright (c) 2003, 2024, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2014, 2020, Red Hat Inc. All rights reserved.
   4  * Copyright (c) 2020, 2023, Huawei Technologies Co., Ltd. All rights reserved.
   5  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   6  *
   7  * This code is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 only, as
   9  * published by the Free Software Foundation.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  *
  25  */
  26 
  27 #include "precompiled.hpp"
  28 #include "asm/macroAssembler.hpp"
  29 #include "asm/macroAssembler.inline.hpp"
  30 #include "code/compiledIC.hpp"
  31 #include "code/debugInfoRec.hpp"
  32 #include "code/vtableStubs.hpp"
  33 #include "compiler/oopMap.hpp"
  34 #include "gc/shared/barrierSetAssembler.hpp"
  35 #include "interpreter/interp_masm.hpp"
  36 #include "interpreter/interpreter.hpp"
  37 #include "logging/log.hpp"
  38 #include "memory/resourceArea.hpp"
  39 #include "nativeInst_riscv.hpp"
  40 #include "oops/klass.inline.hpp"
  41 #include "oops/method.inline.hpp"
  42 #include "prims/methodHandles.hpp"
  43 #include "runtime/continuation.hpp"
  44 #include "runtime/continuationEntry.inline.hpp"
  45 #include "runtime/globals.hpp"
  46 #include "runtime/jniHandles.hpp"
  47 #include "runtime/safepointMechanism.hpp"
  48 #include "runtime/sharedRuntime.hpp"
  49 #include "runtime/signature.hpp"
  50 #include "runtime/stubRoutines.hpp"
  51 #include "runtime/vframeArray.hpp"
  52 #include "utilities/align.hpp"
  53 #include "utilities/formatBuffer.hpp"
  54 #include "vmreg_riscv.inline.hpp"
  55 #ifdef COMPILER1
  56 #include "c1/c1_Runtime1.hpp"
  57 #endif
  58 #ifdef COMPILER2
  59 #include "adfiles/ad_riscv.hpp"
  60 #include "opto/runtime.hpp"
  61 #endif
  62 #if INCLUDE_JVMCI
  63 #include "jvmci/jvmciJavaClasses.hpp"
  64 #endif
  65 
  66 #define __ masm->
  67 
  68 const int StackAlignmentInSlots = StackAlignmentInBytes / VMRegImpl::stack_slot_size;
  69 
  70 class SimpleRuntimeFrame {
  71 public:
  72 
  73   // Most of the runtime stubs have this simple frame layout.
  74   // This class exists to make the layout shared in one place.
  75   // Offsets are for compiler stack slots, which are jints.
  76   enum layout {
  77     // The frame sender code expects that fp will be in the "natural" place and
  78     // will override any oopMap setting for it. We must therefore force the layout
  79     // so that it agrees with the frame sender code.
  80     // we don't expect any arg reg save area so riscv asserts that
  81     // frame::arg_reg_save_area_bytes == 0
  82     fp_off = 0, fp_off2,
  83     return_off, return_off2,
  84     framesize
  85   };
  86 };
  87 
  88 class RegisterSaver {
  89   const bool _save_vectors;
  90  public:
  91   RegisterSaver(bool save_vectors) : _save_vectors(UseRVV && save_vectors) {}
  92   ~RegisterSaver() {}
  93   OopMap* save_live_registers(MacroAssembler* masm, int additional_frame_words, int* total_frame_words);
  94   void restore_live_registers(MacroAssembler* masm);
  95 
  96   // Offsets into the register save area
  97   // Used by deoptimization when it is managing result register
  98   // values on its own
  99   // gregs:28, float_register:32; except: x1(ra) & x2(sp) & gp(x3) & tp(x4)
 100   // |---v0---|<---SP
 101   // |---v1---|save vectors only in generate_handler_blob
 102   // |-- .. --|
 103   // |---v31--|-----
 104   // |---f0---|
 105   // |---f1---|
 106   // |   ..   |
 107   // |---f31--|
 108   // |---reserved slot for stack alignment---|
 109   // |---x5---|
 110   // |   x6   |
 111   // |---.. --|
 112   // |---x31--|
 113   // |---fp---|
 114   // |---ra---|
 115   int v0_offset_in_bytes(void) { return 0; }
 116   int f0_offset_in_bytes(void) {
 117     int f0_offset = 0;
 118 #ifdef COMPILER2
 119     if (_save_vectors) {
 120       f0_offset += Matcher::scalable_vector_reg_size(T_INT) * VectorRegister::number_of_registers *
 121                    BytesPerInt;
 122     }
 123 #endif
 124     return f0_offset;
 125   }
 126   int reserved_slot_offset_in_bytes(void) {
 127     return f0_offset_in_bytes() +
 128            FloatRegister::max_slots_per_register *
 129            FloatRegister::number_of_registers *
 130            BytesPerInt;
 131   }
 132 
 133   int reg_offset_in_bytes(Register r) {
 134     assert (r->encoding() > 4, "ra, sp, gp and tp not saved");
 135     return reserved_slot_offset_in_bytes() + (r->encoding() - 4 /* x1, x2, x3, x4 */) * wordSize;
 136   }
 137 
 138   int freg_offset_in_bytes(FloatRegister f) {
 139     return f0_offset_in_bytes() + f->encoding() * wordSize;
 140   }
 141 
 142   int ra_offset_in_bytes(void) {
 143     return reserved_slot_offset_in_bytes() +
 144            (Register::number_of_registers - 3) *
 145            Register::max_slots_per_register *
 146            BytesPerInt;
 147   }
 148 };
 149 
 150 OopMap* RegisterSaver::save_live_registers(MacroAssembler* masm, int additional_frame_words, int* total_frame_words) {
 151   int vector_size_in_bytes = 0;
 152   int vector_size_in_slots = 0;
 153 #ifdef COMPILER2
 154   if (_save_vectors) {
 155     vector_size_in_bytes += Matcher::scalable_vector_reg_size(T_BYTE);
 156     vector_size_in_slots += Matcher::scalable_vector_reg_size(T_INT);
 157   }
 158 #endif
 159 
 160   int frame_size_in_bytes = align_up(additional_frame_words * wordSize + ra_offset_in_bytes() + wordSize, 16);
 161   // OopMap frame size is in compiler stack slots (jint's) not bytes or words
 162   int frame_size_in_slots = frame_size_in_bytes / BytesPerInt;
 163   // The caller will allocate additional_frame_words
 164   int additional_frame_slots = additional_frame_words * wordSize / BytesPerInt;
 165   // CodeBlob frame size is in words.
 166   int frame_size_in_words = frame_size_in_bytes / wordSize;
 167   *total_frame_words = frame_size_in_words;
 168 
 169   // Save Integer, Float and Vector registers.
 170   __ enter();
 171   __ push_CPU_state(_save_vectors, vector_size_in_bytes);
 172 
 173   // Set an oopmap for the call site.  This oopmap will map all
 174   // oop-registers and debug-info registers as callee-saved.  This
 175   // will allow deoptimization at this safepoint to find all possible
 176   // debug-info recordings, as well as let GC find all oops.
 177 
 178   OopMapSet *oop_maps = new OopMapSet();
 179   OopMap* oop_map = new OopMap(frame_size_in_slots, 0);
 180   assert_cond(oop_maps != nullptr && oop_map != nullptr);
 181 
 182   int sp_offset_in_slots = 0;
 183   int step_in_slots = 0;
 184   if (_save_vectors) {
 185     step_in_slots = vector_size_in_slots;
 186     for (int i = 0; i < VectorRegister::number_of_registers; i++, sp_offset_in_slots += step_in_slots) {
 187       VectorRegister r = as_VectorRegister(i);
 188       oop_map->set_callee_saved(VMRegImpl::stack2reg(sp_offset_in_slots), r->as_VMReg());
 189     }
 190   }
 191 
 192   step_in_slots = FloatRegister::max_slots_per_register;
 193   for (int i = 0; i < FloatRegister::number_of_registers; i++, sp_offset_in_slots += step_in_slots) {
 194     FloatRegister r = as_FloatRegister(i);
 195     oop_map->set_callee_saved(VMRegImpl::stack2reg(sp_offset_in_slots), r->as_VMReg());
 196   }
 197 
 198   step_in_slots = Register::max_slots_per_register;
 199   // skip the slot reserved for alignment, see MacroAssembler::push_reg;
 200   // also skip x5 ~ x6 on the stack because they are caller-saved registers.
 201   sp_offset_in_slots += Register::max_slots_per_register * 3;
 202   // besides, we ignore x0 ~ x4 because push_CPU_state won't push them on the stack.
 203   for (int i = 7; i < Register::number_of_registers; i++, sp_offset_in_slots += step_in_slots) {
 204     Register r = as_Register(i);
 205     if (r != xthread) {
 206       oop_map->set_callee_saved(VMRegImpl::stack2reg(sp_offset_in_slots + additional_frame_slots), r->as_VMReg());
 207     }
 208   }
 209 
 210   return oop_map;
 211 }
 212 
 213 void RegisterSaver::restore_live_registers(MacroAssembler* masm) {
 214 #ifdef COMPILER2
 215   __ pop_CPU_state(_save_vectors, Matcher::scalable_vector_reg_size(T_BYTE));
 216 #else
 217 #if !INCLUDE_JVMCI
 218   assert(!_save_vectors, "vectors are generated only by C2 and JVMCI");
 219 #endif
 220   __ pop_CPU_state(_save_vectors);
 221 #endif
 222   __ leave();
 223 }
 224 
 225 // Is vector's size (in bytes) bigger than a size saved by default?
 226 // riscv does not ovlerlay the floating-point registers on vector registers like aarch64.
 227 bool SharedRuntime::is_wide_vector(int size) {
 228   return UseRVV;
 229 }
 230 
 231 // ---------------------------------------------------------------------------
 232 // Read the array of BasicTypes from a signature, and compute where the
 233 // arguments should go.  Values in the VMRegPair regs array refer to 4-byte
 234 // quantities.  Values less than VMRegImpl::stack0 are registers, those above
 235 // refer to 4-byte stack slots.  All stack slots are based off of the stack pointer
 236 // as framesizes are fixed.
 237 // VMRegImpl::stack0 refers to the first slot 0(sp).
 238 // and VMRegImpl::stack0+1 refers to the memory word 4-byes higher.
 239 // Register up to Register::number_of_registers) are the 64-bit
 240 // integer registers.
 241 
 242 // Note: the INPUTS in sig_bt are in units of Java argument words,
 243 // which are 64-bit.  The OUTPUTS are in 32-bit units.
 244 
 245 // The Java calling convention is a "shifted" version of the C ABI.
 246 // By skipping the first C ABI register we can call non-static jni
 247 // methods with small numbers of arguments without having to shuffle
 248 // the arguments at all. Since we control the java ABI we ought to at
 249 // least get some advantage out of it.
 250 
 251 int SharedRuntime::java_calling_convention(const BasicType *sig_bt,
 252                                            VMRegPair *regs,
 253                                            int total_args_passed) {
 254   // Create the mapping between argument positions and
 255   // registers.
 256   static const Register INT_ArgReg[Argument::n_int_register_parameters_j] = {
 257     j_rarg0, j_rarg1, j_rarg2, j_rarg3,
 258     j_rarg4, j_rarg5, j_rarg6, j_rarg7
 259   };
 260   static const FloatRegister FP_ArgReg[Argument::n_float_register_parameters_j] = {
 261     j_farg0, j_farg1, j_farg2, j_farg3,
 262     j_farg4, j_farg5, j_farg6, j_farg7
 263   };
 264 
 265   uint int_args = 0;
 266   uint fp_args = 0;
 267   uint stk_args = 0;
 268 
 269   for (int i = 0; i < total_args_passed; i++) {
 270     switch (sig_bt[i]) {
 271       case T_BOOLEAN: // fall through
 272       case T_CHAR:    // fall through
 273       case T_BYTE:    // fall through
 274       case T_SHORT:   // fall through
 275       case T_INT:
 276         if (int_args < Argument::n_int_register_parameters_j) {
 277           regs[i].set1(INT_ArgReg[int_args++]->as_VMReg());
 278         } else {
 279           stk_args = align_up(stk_args, 2);
 280           regs[i].set1(VMRegImpl::stack2reg(stk_args));
 281           stk_args += 1;
 282         }
 283         break;
 284       case T_VOID:
 285         // halves of T_LONG or T_DOUBLE
 286         assert(i != 0 && (sig_bt[i - 1] == T_LONG || sig_bt[i - 1] == T_DOUBLE), "expecting half");
 287         regs[i].set_bad();
 288         break;
 289       case T_LONG:      // fall through
 290         assert((i + 1) < total_args_passed && sig_bt[i + 1] == T_VOID, "expecting half");
 291       case T_OBJECT:    // fall through
 292       case T_ARRAY:     // fall through
 293       case T_ADDRESS:
 294         if (int_args < Argument::n_int_register_parameters_j) {
 295           regs[i].set2(INT_ArgReg[int_args++]->as_VMReg());
 296         } else {
 297           stk_args = align_up(stk_args, 2);
 298           regs[i].set2(VMRegImpl::stack2reg(stk_args));
 299           stk_args += 2;
 300         }
 301         break;
 302       case T_FLOAT:
 303         if (fp_args < Argument::n_float_register_parameters_j) {
 304           regs[i].set1(FP_ArgReg[fp_args++]->as_VMReg());
 305         } else {
 306           stk_args = align_up(stk_args, 2);
 307           regs[i].set1(VMRegImpl::stack2reg(stk_args));
 308           stk_args += 1;
 309         }
 310         break;
 311       case T_DOUBLE:
 312         assert((i + 1) < total_args_passed && sig_bt[i + 1] == T_VOID, "expecting half");
 313         if (fp_args < Argument::n_float_register_parameters_j) {
 314           regs[i].set2(FP_ArgReg[fp_args++]->as_VMReg());
 315         } else {
 316           stk_args = align_up(stk_args, 2);
 317           regs[i].set2(VMRegImpl::stack2reg(stk_args));
 318           stk_args += 2;
 319         }
 320         break;
 321       default:
 322         ShouldNotReachHere();
 323     }
 324   }
 325 
 326   return stk_args;
 327 }
 328 
 329 // Patch the callers callsite with entry to compiled code if it exists.
 330 static void patch_callers_callsite(MacroAssembler *masm) {
 331   Label L;
 332   __ ld(t0, Address(xmethod, in_bytes(Method::code_offset())));
 333   __ beqz(t0, L);
 334 
 335   __ enter();
 336   __ push_CPU_state();
 337 
 338   // VM needs caller's callsite
 339   // VM needs target method
 340   // This needs to be a long call since we will relocate this adapter to
 341   // the codeBuffer and it may not reach
 342 
 343 #ifndef PRODUCT
 344   assert(frame::arg_reg_save_area_bytes == 0, "not expecting frame reg save area");
 345 #endif
 346 
 347   __ mv(c_rarg0, xmethod);
 348   __ mv(c_rarg1, ra);
 349   __ rt_call(CAST_FROM_FN_PTR(address, SharedRuntime::fixup_callers_callsite));
 350 
 351   __ pop_CPU_state();
 352   // restore sp
 353   __ leave();
 354   __ bind(L);
 355 }
 356 
 357 static void gen_c2i_adapter(MacroAssembler *masm,
 358                             int total_args_passed,
 359                             int comp_args_on_stack,
 360                             const BasicType *sig_bt,
 361                             const VMRegPair *regs,
 362                             Label& skip_fixup) {
 363   // Before we get into the guts of the C2I adapter, see if we should be here
 364   // at all.  We've come from compiled code and are attempting to jump to the
 365   // interpreter, which means the caller made a static call to get here
 366   // (vcalls always get a compiled target if there is one).  Check for a
 367   // compiled target.  If there is one, we need to patch the caller's call.
 368   patch_callers_callsite(masm);
 369 
 370   __ bind(skip_fixup);
 371 
 372   int words_pushed = 0;
 373 
 374   // Since all args are passed on the stack, total_args_passed *
 375   // Interpreter::stackElementSize is the space we need.
 376 
 377   int extraspace = total_args_passed * Interpreter::stackElementSize;
 378 
 379   __ mv(x19_sender_sp, sp);
 380 
 381   // stack is aligned, keep it that way
 382   extraspace = align_up(extraspace, 2 * wordSize);
 383 
 384   if (extraspace) {
 385     __ sub(sp, sp, extraspace);
 386   }
 387 
 388   // Now write the args into the outgoing interpreter space
 389   for (int i = 0; i < total_args_passed; i++) {
 390     if (sig_bt[i] == T_VOID) {
 391       assert(i > 0 && (sig_bt[i - 1] == T_LONG || sig_bt[i - 1] == T_DOUBLE), "missing half");
 392       continue;
 393     }
 394 
 395     // offset to start parameters
 396     int st_off   = (total_args_passed - i - 1) * Interpreter::stackElementSize;
 397     int next_off = st_off - Interpreter::stackElementSize;
 398 
 399     // Say 4 args:
 400     // i   st_off
 401     // 0   32 T_LONG
 402     // 1   24 T_VOID
 403     // 2   16 T_OBJECT
 404     // 3    8 T_BOOL
 405     // -    0 return address
 406     //
 407     // However to make thing extra confusing. Because we can fit a Java long/double in
 408     // a single slot on a 64 bt vm and it would be silly to break them up, the interpreter
 409     // leaves one slot empty and only stores to a single slot. In this case the
 410     // slot that is occupied is the T_VOID slot. See I said it was confusing.
 411 
 412     VMReg r_1 = regs[i].first();
 413     VMReg r_2 = regs[i].second();
 414     if (!r_1->is_valid()) {
 415       assert(!r_2->is_valid(), "");
 416       continue;
 417     }
 418     if (r_1->is_stack()) {
 419       // memory to memory use t0
 420       int ld_off = (r_1->reg2stack() * VMRegImpl::stack_slot_size
 421                     + extraspace
 422                     + words_pushed * wordSize);
 423       if (!r_2->is_valid()) {
 424         __ lwu(t0, Address(sp, ld_off));
 425         __ sd(t0, Address(sp, st_off), /*temp register*/esp);
 426       } else {
 427         __ ld(t0, Address(sp, ld_off), /*temp register*/esp);
 428 
 429         // Two VMREgs|OptoRegs can be T_OBJECT, T_ADDRESS, T_DOUBLE, T_LONG
 430         // T_DOUBLE and T_LONG use two slots in the interpreter
 431         if (sig_bt[i] == T_LONG || sig_bt[i] == T_DOUBLE) {
 432           // ld_off == LSW, ld_off+wordSize == MSW
 433           // st_off == MSW, next_off == LSW
 434           __ sd(t0, Address(sp, next_off), /*temp register*/esp);
 435 #ifdef ASSERT
 436           // Overwrite the unused slot with known junk
 437           __ mv(t0, 0xdeadffffdeadaaaaul);
 438           __ sd(t0, Address(sp, st_off), /*temp register*/esp);
 439 #endif /* ASSERT */
 440         } else {
 441           __ sd(t0, Address(sp, st_off), /*temp register*/esp);
 442         }
 443       }
 444     } else if (r_1->is_Register()) {
 445       Register r = r_1->as_Register();
 446       if (!r_2->is_valid()) {
 447         // must be only an int (or less ) so move only 32bits to slot
 448         __ sd(r, Address(sp, st_off));
 449       } else {
 450         // Two VMREgs|OptoRegs can be T_OBJECT, T_ADDRESS, T_DOUBLE, T_LONG
 451         // T_DOUBLE and T_LONG use two slots in the interpreter
 452         if ( sig_bt[i] == T_LONG || sig_bt[i] == T_DOUBLE) {
 453           // long/double in gpr
 454 #ifdef ASSERT
 455           // Overwrite the unused slot with known junk
 456           __ mv(t0, 0xdeadffffdeadaaabul);
 457           __ sd(t0, Address(sp, st_off), /*temp register*/esp);
 458 #endif /* ASSERT */
 459           __ sd(r, Address(sp, next_off));
 460         } else {
 461           __ sd(r, Address(sp, st_off));
 462         }
 463       }
 464     } else {
 465       assert(r_1->is_FloatRegister(), "");
 466       if (!r_2->is_valid()) {
 467         // only a float use just part of the slot
 468         __ fsw(r_1->as_FloatRegister(), Address(sp, st_off));
 469       } else {
 470 #ifdef ASSERT
 471         // Overwrite the unused slot with known junk
 472         __ mv(t0, 0xdeadffffdeadaaacul);
 473         __ sd(t0, Address(sp, st_off), /*temp register*/esp);
 474 #endif /* ASSERT */
 475         __ fsd(r_1->as_FloatRegister(), Address(sp, next_off));
 476       }
 477     }
 478   }
 479 
 480   __ mv(esp, sp); // Interp expects args on caller's expression stack
 481 
 482   __ ld(t0, Address(xmethod, in_bytes(Method::interpreter_entry_offset())));
 483   __ jr(t0);
 484 }
 485 
 486 void SharedRuntime::gen_i2c_adapter(MacroAssembler *masm,
 487                                     int total_args_passed,
 488                                     int comp_args_on_stack,
 489                                     const BasicType *sig_bt,
 490                                     const VMRegPair *regs) {
 491   // Note: x19_sender_sp contains the senderSP on entry. We must
 492   // preserve it since we may do a i2c -> c2i transition if we lose a
 493   // race where compiled code goes non-entrant while we get args
 494   // ready.
 495 
 496   // Cut-out for having no stack args.
 497   int comp_words_on_stack = align_up(comp_args_on_stack * VMRegImpl::stack_slot_size, wordSize) >> LogBytesPerWord;
 498   if (comp_args_on_stack != 0) {
 499     __ sub(t0, sp, comp_words_on_stack * wordSize);
 500     __ andi(sp, t0, -16);
 501   }
 502 
 503   // Will jump to the compiled code just as if compiled code was doing it.
 504   // Pre-load the register-jump target early, to schedule it better.
 505   __ ld(t1, Address(xmethod, in_bytes(Method::from_compiled_offset())));
 506 
 507 #if INCLUDE_JVMCI
 508   if (EnableJVMCI) {
 509     // check if this call should be routed towards a specific entry point
 510     __ ld(t0, Address(xthread, in_bytes(JavaThread::jvmci_alternate_call_target_offset())));
 511     Label no_alternative_target;
 512     __ beqz(t0, no_alternative_target);
 513     __ mv(t1, t0);
 514     __ sd(zr, Address(xthread, in_bytes(JavaThread::jvmci_alternate_call_target_offset())));
 515     __ bind(no_alternative_target);
 516   }
 517 #endif // INCLUDE_JVMCI
 518 
 519   // Now generate the shuffle code.
 520   for (int i = 0; i < total_args_passed; i++) {
 521     if (sig_bt[i] == T_VOID) {
 522       assert(i > 0 && (sig_bt[i - 1] == T_LONG || sig_bt[i - 1] == T_DOUBLE), "missing half");
 523       continue;
 524     }
 525 
 526     // Pick up 0, 1 or 2 words from SP+offset.
 527 
 528     assert(!regs[i].second()->is_valid() || regs[i].first()->next() == regs[i].second(),
 529            "scrambled load targets?");
 530     // Load in argument order going down.
 531     int ld_off = (total_args_passed - i - 1) * Interpreter::stackElementSize;
 532     // Point to interpreter value (vs. tag)
 533     int next_off = ld_off - Interpreter::stackElementSize;
 534 
 535     VMReg r_1 = regs[i].first();
 536     VMReg r_2 = regs[i].second();
 537     if (!r_1->is_valid()) {
 538       assert(!r_2->is_valid(), "");
 539       continue;
 540     }
 541     if (r_1->is_stack()) {
 542       // Convert stack slot to an SP offset (+ wordSize to account for return address )
 543       int st_off = regs[i].first()->reg2stack() * VMRegImpl::stack_slot_size;
 544       if (!r_2->is_valid()) {
 545         __ lw(t0, Address(esp, ld_off));
 546         __ sd(t0, Address(sp, st_off), /*temp register*/t2);
 547       } else {
 548         //
 549         // We are using two optoregs. This can be either T_OBJECT,
 550         // T_ADDRESS, T_LONG, or T_DOUBLE the interpreter allocates
 551         // two slots but only uses one for thr T_LONG or T_DOUBLE case
 552         // So we must adjust where to pick up the data to match the
 553         // interpreter.
 554         //
 555         // Interpreter local[n] == MSW, local[n+1] == LSW however locals
 556         // are accessed as negative so LSW is at LOW address
 557 
 558         // ld_off is MSW so get LSW
 559         const int offset = (sig_bt[i] == T_LONG || sig_bt[i] == T_DOUBLE) ?
 560                            next_off : ld_off;
 561         __ ld(t0, Address(esp, offset));
 562         // st_off is LSW (i.e. reg.first())
 563         __ sd(t0, Address(sp, st_off), /*temp register*/t2);
 564       }
 565     } else if (r_1->is_Register()) {  // Register argument
 566       Register r = r_1->as_Register();
 567       if (r_2->is_valid()) {
 568         //
 569         // We are using two VMRegs. This can be either T_OBJECT,
 570         // T_ADDRESS, T_LONG, or T_DOUBLE the interpreter allocates
 571         // two slots but only uses one for thr T_LONG or T_DOUBLE case
 572         // So we must adjust where to pick up the data to match the
 573         // interpreter.
 574 
 575         const int offset = (sig_bt[i] == T_LONG || sig_bt[i] == T_DOUBLE) ?
 576                            next_off : ld_off;
 577 
 578         // this can be a misaligned move
 579         __ ld(r, Address(esp, offset));
 580       } else {
 581         // sign extend and use a full word?
 582         __ lw(r, Address(esp, ld_off));
 583       }
 584     } else {
 585       if (!r_2->is_valid()) {
 586         __ flw(r_1->as_FloatRegister(), Address(esp, ld_off));
 587       } else {
 588         __ fld(r_1->as_FloatRegister(), Address(esp, next_off));
 589       }
 590     }
 591   }
 592 
 593   __ push_cont_fastpath(xthread); // Set JavaThread::_cont_fastpath to the sp of the oldest interpreted frame we know about
 594 
 595   // 6243940 We might end up in handle_wrong_method if
 596   // the callee is deoptimized as we race thru here. If that
 597   // happens we don't want to take a safepoint because the
 598   // caller frame will look interpreted and arguments are now
 599   // "compiled" so it is much better to make this transition
 600   // invisible to the stack walking code. Unfortunately if
 601   // we try and find the callee by normal means a safepoint
 602   // is possible. So we stash the desired callee in the thread
 603   // and the vm will find there should this case occur.
 604 
 605   __ sd(xmethod, Address(xthread, JavaThread::callee_target_offset()));
 606 
 607   __ jr(t1);
 608 }
 609 
 610 // ---------------------------------------------------------------
 611 AdapterHandlerEntry* SharedRuntime::generate_i2c2i_adapters(MacroAssembler *masm,
 612                                                             int total_args_passed,
 613                                                             int comp_args_on_stack,
 614                                                             const BasicType *sig_bt,
 615                                                             const VMRegPair *regs,
 616                                                             AdapterFingerPrint* fingerprint) {
 617   address i2c_entry = __ pc();
 618   gen_i2c_adapter(masm, total_args_passed, comp_args_on_stack, sig_bt, regs);
 619 
 620   address c2i_unverified_entry = __ pc();
 621   Label skip_fixup;
 622 
 623   const Register receiver = j_rarg0;
 624   const Register data = t1;
 625   const Register tmp = t2;  // A call-clobbered register not used for arg passing
 626 
 627   // -------------------------------------------------------------------------
 628   // Generate a C2I adapter.  On entry we know xmethod holds the Method* during calls
 629   // to the interpreter.  The args start out packed in the compiled layout.  They
 630   // need to be unpacked into the interpreter layout.  This will almost always
 631   // require some stack space.  We grow the current (compiled) stack, then repack
 632   // the args.  We  finally end in a jump to the generic interpreter entry point.
 633   // On exit from the interpreter, the interpreter will restore our SP (lest the
 634   // compiled code, which relies solely on SP and not FP, get sick).
 635 
 636   {
 637     __ block_comment("c2i_unverified_entry {");
 638 
 639     __ ic_check();
 640     __ ld(xmethod, Address(data, CompiledICData::speculated_method_offset()));
 641 
 642     __ ld(t0, Address(xmethod, in_bytes(Method::code_offset())));
 643     __ beqz(t0, skip_fixup);
 644     __ far_jump(RuntimeAddress(SharedRuntime::get_ic_miss_stub()));
 645     __ block_comment("} c2i_unverified_entry");
 646   }
 647 
 648   address c2i_entry = __ pc();
 649 
 650   // Class initialization barrier for static methods
 651   address c2i_no_clinit_check_entry = nullptr;
 652   if (VM_Version::supports_fast_class_init_checks()) {
 653     Label L_skip_barrier;
 654 
 655     { // Bypass the barrier for non-static methods
 656       __ lwu(t0, Address(xmethod, Method::access_flags_offset()));
 657       __ test_bit(t1, t0, exact_log2(JVM_ACC_STATIC));
 658       __ beqz(t1, L_skip_barrier); // non-static
 659     }
 660 
 661     __ load_method_holder(t1, xmethod);
 662     __ clinit_barrier(t1, t0, &L_skip_barrier);
 663     __ far_jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub()));
 664 
 665     __ bind(L_skip_barrier);
 666     c2i_no_clinit_check_entry = __ pc();
 667   }
 668 
 669   BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
 670   bs->c2i_entry_barrier(masm);
 671 
 672   gen_c2i_adapter(masm, total_args_passed, comp_args_on_stack, sig_bt, regs, skip_fixup);
 673 
 674   return AdapterHandlerLibrary::new_entry(fingerprint, i2c_entry, c2i_entry, c2i_unverified_entry, c2i_no_clinit_check_entry);
 675 }
 676 
 677 int SharedRuntime::vector_calling_convention(VMRegPair *regs,
 678                                              uint num_bits,
 679                                              uint total_args_passed) {
 680   Unimplemented();
 681   return 0;
 682 }
 683 
 684 int SharedRuntime::c_calling_convention(const BasicType *sig_bt,
 685                                          VMRegPair *regs,
 686                                          int total_args_passed) {
 687 
 688   // We return the amount of VMRegImpl stack slots we need to reserve for all
 689   // the arguments NOT counting out_preserve_stack_slots.
 690 
 691   static const Register INT_ArgReg[Argument::n_int_register_parameters_c] = {
 692     c_rarg0, c_rarg1, c_rarg2, c_rarg3,
 693     c_rarg4, c_rarg5,  c_rarg6,  c_rarg7
 694   };
 695   static const FloatRegister FP_ArgReg[Argument::n_float_register_parameters_c] = {
 696     c_farg0, c_farg1, c_farg2, c_farg3,
 697     c_farg4, c_farg5, c_farg6, c_farg7
 698   };
 699 
 700   uint int_args = 0;
 701   uint fp_args = 0;
 702   uint stk_args = 0; // inc by 2 each time
 703 
 704   for (int i = 0; i < total_args_passed; i++) {
 705     switch (sig_bt[i]) {
 706       case T_BOOLEAN:  // fall through
 707       case T_CHAR:     // fall through
 708       case T_BYTE:     // fall through
 709       case T_SHORT:    // fall through
 710       case T_INT:
 711         if (int_args < Argument::n_int_register_parameters_c) {
 712           regs[i].set1(INT_ArgReg[int_args++]->as_VMReg());
 713         } else {
 714           regs[i].set1(VMRegImpl::stack2reg(stk_args));
 715           stk_args += 2;
 716         }
 717         break;
 718       case T_LONG:      // fall through
 719         assert((i + 1) < total_args_passed && sig_bt[i + 1] == T_VOID, "expecting half");
 720       case T_OBJECT:    // fall through
 721       case T_ARRAY:     // fall through
 722       case T_ADDRESS:   // fall through
 723       case T_METADATA:
 724         if (int_args < Argument::n_int_register_parameters_c) {
 725           regs[i].set2(INT_ArgReg[int_args++]->as_VMReg());
 726         } else {
 727           regs[i].set2(VMRegImpl::stack2reg(stk_args));
 728           stk_args += 2;
 729         }
 730         break;
 731       case T_FLOAT:
 732         if (fp_args < Argument::n_float_register_parameters_c) {
 733           regs[i].set1(FP_ArgReg[fp_args++]->as_VMReg());
 734         } else if (int_args < Argument::n_int_register_parameters_c) {
 735           regs[i].set1(INT_ArgReg[int_args++]->as_VMReg());
 736         } else {
 737           regs[i].set1(VMRegImpl::stack2reg(stk_args));
 738           stk_args += 2;
 739         }
 740         break;
 741       case T_DOUBLE:
 742         assert((i + 1) < total_args_passed && sig_bt[i + 1] == T_VOID, "expecting half");
 743         if (fp_args < Argument::n_float_register_parameters_c) {
 744           regs[i].set2(FP_ArgReg[fp_args++]->as_VMReg());
 745         } else if (int_args < Argument::n_int_register_parameters_c) {
 746           regs[i].set2(INT_ArgReg[int_args++]->as_VMReg());
 747         } else {
 748           regs[i].set2(VMRegImpl::stack2reg(stk_args));
 749           stk_args += 2;
 750         }
 751         break;
 752       case T_VOID: // Halves of longs and doubles
 753         assert(i != 0 && (sig_bt[i - 1] == T_LONG || sig_bt[i - 1] == T_DOUBLE), "expecting half");
 754         regs[i].set_bad();
 755         break;
 756       default:
 757         ShouldNotReachHere();
 758     }
 759   }
 760 
 761   return stk_args;
 762 }
 763 
 764 void SharedRuntime::save_native_result(MacroAssembler *masm, BasicType ret_type, int frame_slots) {
 765   // We always ignore the frame_slots arg and just use the space just below frame pointer
 766   // which by this time is free to use
 767   switch (ret_type) {
 768     case T_FLOAT:
 769       __ fsw(f10, Address(fp, -3 * wordSize));
 770       break;
 771     case T_DOUBLE:
 772       __ fsd(f10, Address(fp, -3 * wordSize));
 773       break;
 774     case T_VOID:  break;
 775     default: {
 776       __ sd(x10, Address(fp, -3 * wordSize));
 777     }
 778   }
 779 }
 780 
 781 void SharedRuntime::restore_native_result(MacroAssembler *masm, BasicType ret_type, int frame_slots) {
 782   // We always ignore the frame_slots arg and just use the space just below frame pointer
 783   // which by this time is free to use
 784   switch (ret_type) {
 785     case T_FLOAT:
 786       __ flw(f10, Address(fp, -3 * wordSize));
 787       break;
 788     case T_DOUBLE:
 789       __ fld(f10, Address(fp, -3 * wordSize));
 790       break;
 791     case T_VOID:  break;
 792     default: {
 793       __ ld(x10, Address(fp, -3 * wordSize));
 794     }
 795   }
 796 }
 797 
 798 static void save_args(MacroAssembler *masm, int arg_count, int first_arg, VMRegPair *args) {
 799   RegSet x;
 800   for ( int i = first_arg ; i < arg_count ; i++ ) {
 801     if (args[i].first()->is_Register()) {
 802       x = x + args[i].first()->as_Register();
 803     } else if (args[i].first()->is_FloatRegister()) {
 804       __ addi(sp, sp, -2 * wordSize);
 805       __ fsd(args[i].first()->as_FloatRegister(), Address(sp, 0));
 806     }
 807   }
 808   __ push_reg(x, sp);
 809 }
 810 
 811 static void restore_args(MacroAssembler *masm, int arg_count, int first_arg, VMRegPair *args) {
 812   RegSet x;
 813   for ( int i = first_arg ; i < arg_count ; i++ ) {
 814     if (args[i].first()->is_Register()) {
 815       x = x + args[i].first()->as_Register();
 816     } else {
 817       ;
 818     }
 819   }
 820   __ pop_reg(x, sp);
 821   for ( int i = arg_count - 1 ; i >= first_arg ; i-- ) {
 822     if (args[i].first()->is_Register()) {
 823       ;
 824     } else if (args[i].first()->is_FloatRegister()) {
 825       __ fld(args[i].first()->as_FloatRegister(), Address(sp, 0));
 826       __ add(sp, sp, 2 * wordSize);
 827     }
 828   }
 829 }
 830 
 831 static void verify_oop_args(MacroAssembler* masm,
 832                             const methodHandle& method,
 833                             const BasicType* sig_bt,
 834                             const VMRegPair* regs) {
 835   const Register temp_reg = x9;  // not part of any compiled calling seq
 836   if (VerifyOops) {
 837     for (int i = 0; i < method->size_of_parameters(); i++) {
 838       if (sig_bt[i] == T_OBJECT ||
 839           sig_bt[i] == T_ARRAY) {
 840         VMReg r = regs[i].first();
 841         assert(r->is_valid(), "bad oop arg");
 842         if (r->is_stack()) {
 843           __ ld(temp_reg, Address(sp, r->reg2stack() * VMRegImpl::stack_slot_size));
 844           __ verify_oop(temp_reg);
 845         } else {
 846           __ verify_oop(r->as_Register());
 847         }
 848       }
 849     }
 850   }
 851 }
 852 
 853 // on exit, sp points to the ContinuationEntry
 854 static OopMap* continuation_enter_setup(MacroAssembler* masm, int& stack_slots) {
 855   assert(ContinuationEntry::size() % VMRegImpl::stack_slot_size == 0, "");
 856   assert(in_bytes(ContinuationEntry::cont_offset())  % VMRegImpl::stack_slot_size == 0, "");
 857   assert(in_bytes(ContinuationEntry::chunk_offset()) % VMRegImpl::stack_slot_size == 0, "");
 858 
 859   stack_slots += (int)ContinuationEntry::size() / wordSize;
 860   __ sub(sp, sp, (int)ContinuationEntry::size()); // place Continuation metadata
 861 
 862   OopMap* map = new OopMap(((int)ContinuationEntry::size() + wordSize) / VMRegImpl::stack_slot_size, 0 /* arg_slots*/);
 863 
 864   __ ld(t0, Address(xthread, JavaThread::cont_entry_offset()));
 865   __ sd(t0, Address(sp, ContinuationEntry::parent_offset()));
 866   __ sd(sp, Address(xthread, JavaThread::cont_entry_offset()));
 867 
 868   return map;
 869 }
 870 
 871 // on entry c_rarg1 points to the continuation
 872 //          sp points to ContinuationEntry
 873 //          c_rarg3 -- isVirtualThread
 874 static void fill_continuation_entry(MacroAssembler* masm) {
 875 #ifdef ASSERT
 876   __ mv(t0, ContinuationEntry::cookie_value());
 877   __ sw(t0, Address(sp, ContinuationEntry::cookie_offset()));
 878 #endif
 879 
 880   __ sd(c_rarg1, Address(sp, ContinuationEntry::cont_offset()));
 881   __ sw(c_rarg3, Address(sp, ContinuationEntry::flags_offset()));
 882   __ sd(zr,      Address(sp, ContinuationEntry::chunk_offset()));
 883   __ sw(zr,      Address(sp, ContinuationEntry::argsize_offset()));
 884   __ sw(zr,      Address(sp, ContinuationEntry::pin_count_offset()));
 885 
 886   __ ld(t0, Address(xthread, JavaThread::cont_fastpath_offset()));
 887   __ sd(t0, Address(sp, ContinuationEntry::parent_cont_fastpath_offset()));
 888   __ ld(t0, Address(xthread, JavaThread::held_monitor_count_offset()));
 889   __ sd(t0, Address(sp, ContinuationEntry::parent_held_monitor_count_offset()));
 890 
 891   __ sd(zr, Address(xthread, JavaThread::cont_fastpath_offset()));
 892   __ sd(zr, Address(xthread, JavaThread::held_monitor_count_offset()));
 893 }
 894 
 895 // on entry, sp points to the ContinuationEntry
 896 // on exit, fp points to the spilled fp + 2 * wordSize in the entry frame
 897 static void continuation_enter_cleanup(MacroAssembler* masm) {
 898 #ifndef PRODUCT
 899   Label OK;
 900   __ ld(t0, Address(xthread, JavaThread::cont_entry_offset()));
 901   __ beq(sp, t0, OK);
 902   __ stop("incorrect sp");
 903   __ bind(OK);
 904 #endif
 905 
 906   __ ld(t0, Address(sp, ContinuationEntry::parent_cont_fastpath_offset()));
 907   __ sd(t0, Address(xthread, JavaThread::cont_fastpath_offset()));
 908 
 909   if (CheckJNICalls) {
 910     // Check if this is a virtual thread continuation
 911     Label L_skip_vthread_code;
 912     __ lwu(t0, Address(sp, ContinuationEntry::flags_offset()));
 913     __ beqz(t0, L_skip_vthread_code);
 914 
 915     // If the held monitor count is > 0 and this vthread is terminating then
 916     // it failed to release a JNI monitor. So we issue the same log message
 917     // that JavaThread::exit does.
 918     __ ld(t0, Address(xthread, JavaThread::jni_monitor_count_offset()));
 919     __ beqz(t0, L_skip_vthread_code);
 920 
 921     // Save return value potentially containing the exception oop in callee-saved x9
 922     __ mv(x9, x10);
 923     __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::log_jni_monitor_still_held));
 924     // Restore potential return value
 925     __ mv(x10, x9);
 926 
 927     // For vthreads we have to explicitly zero the JNI monitor count of the carrier
 928     // on termination. The held count is implicitly zeroed below when we restore from
 929     // the parent held count (which has to be zero).
 930     __ sd(zr, Address(xthread, JavaThread::jni_monitor_count_offset()));
 931 
 932     __ bind(L_skip_vthread_code);
 933   }
 934 #ifdef ASSERT
 935   else {
 936     // Check if this is a virtual thread continuation
 937     Label L_skip_vthread_code;
 938     __ lwu(t0, Address(sp, ContinuationEntry::flags_offset()));
 939     __ beqz(t0, L_skip_vthread_code);
 940 
 941     // See comment just above. If not checking JNI calls the JNI count is only
 942     // needed for assertion checking.
 943     __ sd(zr, Address(xthread, JavaThread::jni_monitor_count_offset()));
 944 
 945     __ bind(L_skip_vthread_code);
 946   }
 947 #endif
 948 
 949   __ ld(t0, Address(sp, ContinuationEntry::parent_held_monitor_count_offset()));
 950   __ sd(t0, Address(xthread, JavaThread::held_monitor_count_offset()));
 951 
 952   __ ld(t0, Address(sp, ContinuationEntry::parent_offset()));
 953   __ sd(t0, Address(xthread, JavaThread::cont_entry_offset()));
 954   __ add(fp, sp, (int)ContinuationEntry::size() + 2 * wordSize /* 2 extra words to match up with leave() */);
 955 }
 956 
 957 // enterSpecial(Continuation c, boolean isContinue, boolean isVirtualThread)
 958 // On entry: c_rarg1 -- the continuation object
 959 //           c_rarg2 -- isContinue
 960 //           c_rarg3 -- isVirtualThread
 961 static void gen_continuation_enter(MacroAssembler* masm,
 962                                    const methodHandle& method,
 963                                    const BasicType* sig_bt,
 964                                    const VMRegPair* regs,
 965                                    int& exception_offset,
 966                                    OopMapSet*oop_maps,
 967                                    int& frame_complete,
 968                                    int& stack_slots,
 969                                    int& interpreted_entry_offset,
 970                                    int& compiled_entry_offset) {
 971   // verify_oop_args(masm, method, sig_bt, regs);
 972   Address resolve(SharedRuntime::get_resolve_static_call_stub(), relocInfo::static_call_type);
 973 
 974   address start = __ pc();
 975 
 976   Label call_thaw, exit;
 977 
 978   // i2i entry used at interp_only_mode only
 979   interpreted_entry_offset = __ pc() - start;
 980   {
 981 #ifdef ASSERT
 982     Label is_interp_only;
 983     __ lw(t0, Address(xthread, JavaThread::interp_only_mode_offset()));
 984     __ bnez(t0, is_interp_only);
 985     __ stop("enterSpecial interpreter entry called when not in interp_only_mode");
 986     __ bind(is_interp_only);
 987 #endif
 988 
 989     // Read interpreter arguments into registers (this is an ad-hoc i2c adapter)
 990     __ ld(c_rarg1, Address(esp, Interpreter::stackElementSize * 2));
 991     __ ld(c_rarg2, Address(esp, Interpreter::stackElementSize * 1));
 992     __ ld(c_rarg3, Address(esp, Interpreter::stackElementSize * 0));
 993     __ push_cont_fastpath(xthread);
 994 
 995     __ enter();
 996     stack_slots = 2; // will be adjusted in setup
 997     OopMap* map = continuation_enter_setup(masm, stack_slots);
 998     // The frame is complete here, but we only record it for the compiled entry, so the frame would appear unsafe,
 999     // but that's okay because at the very worst we'll miss an async sample, but we're in interp_only_mode anyway.
1000 
1001     fill_continuation_entry(masm);
1002 
1003     __ bnez(c_rarg2, call_thaw);
1004 
1005     // Make sure the call is patchable
1006     __ align(NativeInstruction::instruction_size);
1007 
1008     const address tr_call = __ reloc_call(resolve);
1009     if (tr_call == nullptr) {
1010       fatal("CodeCache is full at gen_continuation_enter");
1011     }
1012 
1013     oop_maps->add_gc_map(__ pc() - start, map);
1014     __ post_call_nop();
1015 
1016     __ j(exit);
1017 
1018     address stub = CompiledDirectCall::emit_to_interp_stub(masm, tr_call);
1019     if (stub == nullptr) {
1020       fatal("CodeCache is full at gen_continuation_enter");
1021     }
1022   }
1023 
1024   // compiled entry
1025   __ align(CodeEntryAlignment);
1026   compiled_entry_offset = __ pc() - start;
1027 
1028   __ enter();
1029   stack_slots = 2; // will be adjusted in setup
1030   OopMap* map = continuation_enter_setup(masm, stack_slots);
1031   frame_complete = __ pc() - start;
1032 
1033   fill_continuation_entry(masm);
1034 
1035   __ bnez(c_rarg2, call_thaw);
1036 
1037   // Make sure the call is patchable
1038   __ align(NativeInstruction::instruction_size);
1039 
1040   const address tr_call = __ reloc_call(resolve);
1041   if (tr_call == nullptr) {
1042     fatal("CodeCache is full at gen_continuation_enter");
1043   }
1044 
1045   oop_maps->add_gc_map(__ pc() - start, map);
1046   __ post_call_nop();
1047 
1048   __ j(exit);
1049 
1050   __ bind(call_thaw);
1051 
1052   __ rt_call(CAST_FROM_FN_PTR(address, StubRoutines::cont_thaw()));
1053   oop_maps->add_gc_map(__ pc() - start, map->deep_copy());
1054   ContinuationEntry::_return_pc_offset = __ pc() - start;
1055   __ post_call_nop();
1056 
1057   __ bind(exit);
1058   continuation_enter_cleanup(masm);
1059   __ leave();
1060   __ ret();
1061 
1062   // exception handling
1063   exception_offset = __ pc() - start;
1064   {
1065     __ mv(x9, x10); // save return value contaning the exception oop in callee-saved x9
1066 
1067     continuation_enter_cleanup(masm);
1068 
1069     __ ld(c_rarg1, Address(fp, -1 * wordSize)); // return address
1070     __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::exception_handler_for_return_address), xthread, c_rarg1);
1071 
1072     // see OptoRuntime::generate_exception_blob: x10 -- exception oop, x13 -- exception pc
1073 
1074     __ mv(x11, x10); // the exception handler
1075     __ mv(x10, x9); // restore return value contaning the exception oop
1076     __ verify_oop(x10);
1077 
1078     __ leave();
1079     __ mv(x13, ra);
1080     __ jr(x11); // the exception handler
1081   }
1082 
1083   address stub = CompiledDirectCall::emit_to_interp_stub(masm, tr_call);
1084   if (stub == nullptr) {
1085     fatal("CodeCache is full at gen_continuation_enter");
1086   }
1087 }
1088 
1089 static void gen_continuation_yield(MacroAssembler* masm,
1090                                    const methodHandle& method,
1091                                    const BasicType* sig_bt,
1092                                    const VMRegPair* regs,
1093                                    OopMapSet* oop_maps,
1094                                    int& frame_complete,
1095                                    int& stack_slots,
1096                                    int& compiled_entry_offset) {
1097   enum layout {
1098     fp_off,
1099     fp_off2,
1100     return_off,
1101     return_off2,
1102     framesize // inclusive of return address
1103   };
1104   // assert(is_even(framesize/2), "sp not 16-byte aligned");
1105 
1106   stack_slots = framesize / VMRegImpl::slots_per_word;
1107   assert(stack_slots == 2, "recheck layout");
1108 
1109   address start = __ pc();
1110 
1111   compiled_entry_offset = __ pc() - start;
1112   __ enter();
1113 
1114   __ mv(c_rarg1, sp);
1115 
1116   frame_complete = __ pc() - start;
1117   address the_pc = __ pc();
1118 
1119   __ post_call_nop(); // this must be exactly after the pc value that is pushed into the frame info, we use this nop for fast CodeBlob lookup
1120 
1121   __ mv(c_rarg0, xthread);
1122   __ set_last_Java_frame(sp, fp, the_pc, t0);
1123   __ call_VM_leaf(Continuation::freeze_entry(), 2);
1124   __ reset_last_Java_frame(true);
1125 
1126   Label pinned;
1127 
1128   __ bnez(x10, pinned);
1129 
1130   // We've succeeded, set sp to the ContinuationEntry
1131   __ ld(sp, Address(xthread, JavaThread::cont_entry_offset()));
1132   continuation_enter_cleanup(masm);
1133 
1134   __ bind(pinned); // pinned -- return to caller
1135 
1136   // handle pending exception thrown by freeze
1137   __ ld(t0, Address(xthread, in_bytes(Thread::pending_exception_offset())));
1138   Label ok;
1139   __ beqz(t0, ok);
1140   __ leave();
1141   __ la(t0, RuntimeAddress(StubRoutines::forward_exception_entry()));
1142   __ jr(t0);
1143   __ bind(ok);
1144 
1145   __ leave();
1146   __ ret();
1147 
1148   OopMap* map = new OopMap(framesize, 1);
1149   oop_maps->add_gc_map(the_pc - start, map);
1150 }
1151 
1152 static void gen_special_dispatch(MacroAssembler* masm,
1153                                  const methodHandle& method,
1154                                  const BasicType* sig_bt,
1155                                  const VMRegPair* regs) {
1156   verify_oop_args(masm, method, sig_bt, regs);
1157   vmIntrinsics::ID iid = method->intrinsic_id();
1158 
1159   // Now write the args into the outgoing interpreter space
1160   bool     has_receiver   = false;
1161   Register receiver_reg   = noreg;
1162   int      member_arg_pos = -1;
1163   Register member_reg     = noreg;
1164   int      ref_kind       = MethodHandles::signature_polymorphic_intrinsic_ref_kind(iid);
1165   if (ref_kind != 0) {
1166     member_arg_pos = method->size_of_parameters() - 1;  // trailing MemberName argument
1167     member_reg = x9;  // known to be free at this point
1168     has_receiver = MethodHandles::ref_kind_has_receiver(ref_kind);
1169   } else if (iid == vmIntrinsics::_invokeBasic) {
1170     has_receiver = true;
1171   } else if (iid == vmIntrinsics::_linkToNative) {
1172     member_arg_pos = method->size_of_parameters() - 1;  // trailing NativeEntryPoint argument
1173     member_reg = x9;  // known to be free at this point
1174   } else {
1175     fatal("unexpected intrinsic id %d", vmIntrinsics::as_int(iid));
1176   }
1177 
1178   if (member_reg != noreg) {
1179     // Load the member_arg into register, if necessary.
1180     SharedRuntime::check_member_name_argument_is_last_argument(method, sig_bt, regs);
1181     VMReg r = regs[member_arg_pos].first();
1182     if (r->is_stack()) {
1183       __ ld(member_reg, Address(sp, r->reg2stack() * VMRegImpl::stack_slot_size));
1184     } else {
1185       // no data motion is needed
1186       member_reg = r->as_Register();
1187     }
1188   }
1189 
1190   if (has_receiver) {
1191     // Make sure the receiver is loaded into a register.
1192     assert(method->size_of_parameters() > 0, "oob");
1193     assert(sig_bt[0] == T_OBJECT, "receiver argument must be an object");
1194     VMReg r = regs[0].first();
1195     assert(r->is_valid(), "bad receiver arg");
1196     if (r->is_stack()) {
1197       // Porting note:  This assumes that compiled calling conventions always
1198       // pass the receiver oop in a register.  If this is not true on some
1199       // platform, pick a temp and load the receiver from stack.
1200       fatal("receiver always in a register");
1201       receiver_reg = x12;  // known to be free at this point
1202       __ ld(receiver_reg, Address(sp, r->reg2stack() * VMRegImpl::stack_slot_size));
1203     } else {
1204       // no data motion is needed
1205       receiver_reg = r->as_Register();
1206     }
1207   }
1208 
1209   // Figure out which address we are really jumping to:
1210   MethodHandles::generate_method_handle_dispatch(masm, iid,
1211                                                  receiver_reg, member_reg, /*for_compiler_entry:*/ true);
1212 }
1213 
1214 // ---------------------------------------------------------------------------
1215 // Generate a native wrapper for a given method.  The method takes arguments
1216 // in the Java compiled code convention, marshals them to the native
1217 // convention (handlizes oops, etc), transitions to native, makes the call,
1218 // returns to java state (possibly blocking), unhandlizes any result and
1219 // returns.
1220 //
1221 // Critical native functions are a shorthand for the use of
1222 // GetPrimtiveArrayCritical and disallow the use of any other JNI
1223 // functions.  The wrapper is expected to unpack the arguments before
1224 // passing them to the callee and perform checks before and after the
1225 // native call to ensure that they GCLocker
1226 // lock_critical/unlock_critical semantics are followed.  Some other
1227 // parts of JNI setup are skipped like the tear down of the JNI handle
1228 // block and the check for pending exceptions it's impossible for them
1229 // to be thrown.
1230 //
1231 // They are roughly structured like this:
1232 //    if (GCLocker::needs_gc()) SharedRuntime::block_for_jni_critical()
1233 //    tranistion to thread_in_native
1234 //    unpack array arguments and call native entry point
1235 //    check for safepoint in progress
1236 //    check if any thread suspend flags are set
1237 //      call into JVM and possible unlock the JNI critical
1238 //      if a GC was suppressed while in the critical native.
1239 //    transition back to thread_in_Java
1240 //    return to caller
1241 //
1242 nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
1243                                                 const methodHandle& method,
1244                                                 int compile_id,
1245                                                 BasicType* in_sig_bt,
1246                                                 VMRegPair* in_regs,
1247                                                 BasicType ret_type) {
1248   if (method->is_continuation_native_intrinsic()) {
1249     int exception_offset = -1;
1250     OopMapSet* oop_maps = new OopMapSet();
1251     int frame_complete = -1;
1252     int stack_slots = -1;
1253     int interpreted_entry_offset = -1;
1254     int vep_offset = -1;
1255     if (method->is_continuation_enter_intrinsic()) {
1256       gen_continuation_enter(masm,
1257                              method,
1258                              in_sig_bt,
1259                              in_regs,
1260                              exception_offset,
1261                              oop_maps,
1262                              frame_complete,
1263                              stack_slots,
1264                              interpreted_entry_offset,
1265                              vep_offset);
1266     } else if (method->is_continuation_yield_intrinsic()) {
1267       gen_continuation_yield(masm,
1268                              method,
1269                              in_sig_bt,
1270                              in_regs,
1271                              oop_maps,
1272                              frame_complete,
1273                              stack_slots,
1274                              vep_offset);
1275     } else {
1276       guarantee(false, "Unknown Continuation native intrinsic");
1277     }
1278 
1279 #ifdef ASSERT
1280     if (method->is_continuation_enter_intrinsic()) {
1281       assert(interpreted_entry_offset != -1, "Must be set");
1282       assert(exception_offset != -1,         "Must be set");
1283     } else {
1284       assert(interpreted_entry_offset == -1, "Must be unset");
1285       assert(exception_offset == -1,         "Must be unset");
1286     }
1287     assert(frame_complete != -1,    "Must be set");
1288     assert(stack_slots != -1,       "Must be set");
1289     assert(vep_offset != -1,        "Must be set");
1290 #endif
1291 
1292     __ flush();
1293     nmethod* nm = nmethod::new_native_nmethod(method,
1294                                               compile_id,
1295                                               masm->code(),
1296                                               vep_offset,
1297                                               frame_complete,
1298                                               stack_slots,
1299                                               in_ByteSize(-1),
1300                                               in_ByteSize(-1),
1301                                               oop_maps,
1302                                               exception_offset);
1303     if (nm == nullptr) return nm;
1304     if (method->is_continuation_enter_intrinsic()) {
1305       ContinuationEntry::set_enter_code(nm, interpreted_entry_offset);
1306     } else if (method->is_continuation_yield_intrinsic()) {
1307       _cont_doYield_stub = nm;
1308     } else {
1309       guarantee(false, "Unknown Continuation native intrinsic");
1310     }
1311     return nm;
1312   }
1313 
1314   if (method->is_method_handle_intrinsic()) {
1315     vmIntrinsics::ID iid = method->intrinsic_id();
1316     intptr_t start = (intptr_t)__ pc();
1317     int vep_offset = ((intptr_t)__ pc()) - start;
1318 
1319     // First instruction must be a nop as it may need to be patched on deoptimisation
1320     {
1321       Assembler::IncompressibleRegion ir(masm);  // keep the nop as 4 bytes for patching.
1322       MacroAssembler::assert_alignment(__ pc());
1323       __ nop();  // 4 bytes
1324     }
1325     gen_special_dispatch(masm,
1326                          method,
1327                          in_sig_bt,
1328                          in_regs);
1329     int frame_complete = ((intptr_t)__ pc()) - start;  // not complete, period
1330     __ flush();
1331     int stack_slots = SharedRuntime::out_preserve_stack_slots();  // no out slots at all, actually
1332     return nmethod::new_native_nmethod(method,
1333                                        compile_id,
1334                                        masm->code(),
1335                                        vep_offset,
1336                                        frame_complete,
1337                                        stack_slots / VMRegImpl::slots_per_word,
1338                                        in_ByteSize(-1),
1339                                        in_ByteSize(-1),
1340                                        (OopMapSet*)nullptr);
1341   }
1342   address native_func = method->native_function();
1343   assert(native_func != nullptr, "must have function");
1344 
1345   // An OopMap for lock (and class if static)
1346   OopMapSet *oop_maps = new OopMapSet();
1347   assert_cond(oop_maps != nullptr);
1348   intptr_t start = (intptr_t)__ pc();
1349 
1350   // We have received a description of where all the java arg are located
1351   // on entry to the wrapper. We need to convert these args to where
1352   // the jni function will expect them. To figure out where they go
1353   // we convert the java signature to a C signature by inserting
1354   // the hidden arguments as arg[0] and possibly arg[1] (static method)
1355 
1356   const int total_in_args = method->size_of_parameters();
1357   int total_c_args = total_in_args + (method->is_static() ? 2 : 1);
1358 
1359   BasicType* out_sig_bt = NEW_RESOURCE_ARRAY(BasicType, total_c_args);
1360   VMRegPair* out_regs   = NEW_RESOURCE_ARRAY(VMRegPair, total_c_args);
1361   BasicType* in_elem_bt = nullptr;
1362 
1363   int argc = 0;
1364   out_sig_bt[argc++] = T_ADDRESS;
1365   if (method->is_static()) {
1366     out_sig_bt[argc++] = T_OBJECT;
1367   }
1368 
1369   for (int i = 0; i < total_in_args ; i++) {
1370     out_sig_bt[argc++] = in_sig_bt[i];
1371   }
1372 
1373   // Now figure out where the args must be stored and how much stack space
1374   // they require.
1375   int out_arg_slots = c_calling_convention(out_sig_bt, out_regs, total_c_args);
1376 
1377   // Compute framesize for the wrapper.  We need to handlize all oops in
1378   // incoming registers
1379 
1380   // Calculate the total number of stack slots we will need.
1381 
1382   // First count the abi requirement plus all of the outgoing args
1383   int stack_slots = SharedRuntime::out_preserve_stack_slots() + out_arg_slots;
1384 
1385   // Now the space for the inbound oop handle area
1386   int total_save_slots = 8 * VMRegImpl::slots_per_word;  // 8 arguments passed in registers
1387 
1388   int oop_handle_offset = stack_slots;
1389   stack_slots += total_save_slots;
1390 
1391   // Now any space we need for handlizing a klass if static method
1392 
1393   int klass_slot_offset = 0;
1394   int klass_offset = -1;
1395   int lock_slot_offset = 0;
1396   bool is_static = false;
1397 
1398   if (method->is_static()) {
1399     klass_slot_offset = stack_slots;
1400     stack_slots += VMRegImpl::slots_per_word;
1401     klass_offset = klass_slot_offset * VMRegImpl::stack_slot_size;
1402     is_static = true;
1403   }
1404 
1405   // Plus a lock if needed
1406 
1407   if (method->is_synchronized()) {
1408     lock_slot_offset = stack_slots;
1409     stack_slots += VMRegImpl::slots_per_word;
1410   }
1411 
1412   // Now a place (+2) to save return values or temp during shuffling
1413   // + 4 for return address (which we own) and saved fp
1414   stack_slots += 6;
1415 
1416   // Ok The space we have allocated will look like:
1417   //
1418   //
1419   // FP-> |                     |
1420   //      | 2 slots (ra)        |
1421   //      | 2 slots (fp)        |
1422   //      |---------------------|
1423   //      | 2 slots for moves   |
1424   //      |---------------------|
1425   //      | lock box (if sync)  |
1426   //      |---------------------| <- lock_slot_offset
1427   //      | klass (if static)   |
1428   //      |---------------------| <- klass_slot_offset
1429   //      | oopHandle area      |
1430   //      |---------------------| <- oop_handle_offset (8 java arg registers)
1431   //      | outbound memory     |
1432   //      | based arguments     |
1433   //      |                     |
1434   //      |---------------------|
1435   //      |                     |
1436   // SP-> | out_preserved_slots |
1437   //
1438   //
1439 
1440 
1441   // Now compute actual number of stack words we need rounding to make
1442   // stack properly aligned.
1443   stack_slots = align_up(stack_slots, StackAlignmentInSlots);
1444 
1445   int stack_size = stack_slots * VMRegImpl::stack_slot_size;
1446 
1447   // First thing make an ic check to see if we should even be here
1448 
1449   // We are free to use all registers as temps without saving them and
1450   // restoring them except fp. fp is the only callee save register
1451   // as far as the interpreter and the compiler(s) are concerned.
1452 
1453 
1454   const Register ic_reg = t1;
1455   const Register receiver = j_rarg0;
1456 
1457   __ verify_oop(receiver);
1458   assert_different_registers(receiver, t0, t1);
1459 
1460   __ ic_check();
1461 
1462   int vep_offset = ((intptr_t)__ pc()) - start;
1463 
1464   // If we have to make this method not-entrant we'll overwrite its
1465   // first instruction with a jump.
1466   {
1467     Assembler::IncompressibleRegion ir(masm);  // keep the nop as 4 bytes for patching.
1468     MacroAssembler::assert_alignment(__ pc());
1469     __ nop();  // 4 bytes
1470   }
1471 
1472   if (VM_Version::supports_fast_class_init_checks() && method->needs_clinit_barrier()) {
1473     Label L_skip_barrier;
1474     __ mov_metadata(t1, method->method_holder()); // InstanceKlass*
1475     __ clinit_barrier(t1, t0, &L_skip_barrier);
1476     __ far_jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub()));
1477 
1478     __ bind(L_skip_barrier);
1479   }
1480 
1481   // Generate stack overflow check
1482   __ bang_stack_with_offset(checked_cast<int>(StackOverflow::stack_shadow_zone_size()));
1483 
1484   // Generate a new frame for the wrapper.
1485   __ enter();
1486   // -2 because return address is already present and so is saved fp
1487   __ sub(sp, sp, stack_size - 2 * wordSize);
1488 
1489   BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
1490   assert_cond(bs != nullptr);
1491   bs->nmethod_entry_barrier(masm, nullptr /* slow_path */, nullptr /* continuation */, nullptr /* guard */);
1492 
1493   // Frame is now completed as far as size and linkage.
1494   int frame_complete = ((intptr_t)__ pc()) - start;
1495 
1496   // We use x18 as the oop handle for the receiver/klass
1497   // It is callee save so it survives the call to native
1498 
1499   const Register oop_handle_reg = x18;
1500 
1501   //
1502   // We immediately shuffle the arguments so that any vm call we have to
1503   // make from here on out (sync slow path, jvmti, etc.) we will have
1504   // captured the oops from our caller and have a valid oopMap for
1505   // them.
1506 
1507   // -----------------
1508   // The Grand Shuffle
1509 
1510   // The Java calling convention is either equal (linux) or denser (win64) than the
1511   // c calling convention. However the because of the jni_env argument the c calling
1512   // convention always has at least one more (and two for static) arguments than Java.
1513   // Therefore if we move the args from java -> c backwards then we will never have
1514   // a register->register conflict and we don't have to build a dependency graph
1515   // and figure out how to break any cycles.
1516   //
1517 
1518   // Record esp-based slot for receiver on stack for non-static methods
1519   int receiver_offset = -1;
1520 
1521   // This is a trick. We double the stack slots so we can claim
1522   // the oops in the caller's frame. Since we are sure to have
1523   // more args than the caller doubling is enough to make
1524   // sure we can capture all the incoming oop args from the
1525   // caller.
1526   //
1527   OopMap* map = new OopMap(stack_slots * 2, 0 /* arg_slots*/);
1528   assert_cond(map != nullptr);
1529 
1530   int float_args = 0;
1531   int int_args = 0;
1532 
1533 #ifdef ASSERT
1534   bool reg_destroyed[Register::number_of_registers];
1535   bool freg_destroyed[FloatRegister::number_of_registers];
1536   for ( int r = 0 ; r < Register::number_of_registers ; r++ ) {
1537     reg_destroyed[r] = false;
1538   }
1539   for ( int f = 0 ; f < FloatRegister::number_of_registers ; f++ ) {
1540     freg_destroyed[f] = false;
1541   }
1542 
1543 #endif /* ASSERT */
1544 
1545   // For JNI natives the incoming and outgoing registers are offset upwards.
1546   GrowableArray<int> arg_order(2 * total_in_args);
1547   VMRegPair tmp_vmreg;
1548   tmp_vmreg.set2(x9->as_VMReg());
1549 
1550   for (int i = total_in_args - 1, c_arg = total_c_args - 1; i >= 0; i--, c_arg--) {
1551     arg_order.push(i);
1552     arg_order.push(c_arg);
1553   }
1554 
1555   int temploc = -1;
1556   for (int ai = 0; ai < arg_order.length(); ai += 2) {
1557     int i = arg_order.at(ai);
1558     int c_arg = arg_order.at(ai + 1);
1559     __ block_comment(err_msg("mv %d -> %d", i, c_arg));
1560     assert(c_arg != -1 && i != -1, "wrong order");
1561 #ifdef ASSERT
1562     if (in_regs[i].first()->is_Register()) {
1563       assert(!reg_destroyed[in_regs[i].first()->as_Register()->encoding()], "destroyed reg!");
1564     } else if (in_regs[i].first()->is_FloatRegister()) {
1565       assert(!freg_destroyed[in_regs[i].first()->as_FloatRegister()->encoding()], "destroyed reg!");
1566     }
1567     if (out_regs[c_arg].first()->is_Register()) {
1568       reg_destroyed[out_regs[c_arg].first()->as_Register()->encoding()] = true;
1569     } else if (out_regs[c_arg].first()->is_FloatRegister()) {
1570       freg_destroyed[out_regs[c_arg].first()->as_FloatRegister()->encoding()] = true;
1571     }
1572 #endif /* ASSERT */
1573     switch (in_sig_bt[i]) {
1574       case T_ARRAY:
1575       case T_OBJECT:
1576         __ object_move(map, oop_handle_offset, stack_slots, in_regs[i], out_regs[c_arg],
1577                        ((i == 0) && (!is_static)),
1578                        &receiver_offset);
1579         int_args++;
1580         break;
1581       case T_VOID:
1582         break;
1583 
1584       case T_FLOAT:
1585         __ float_move(in_regs[i], out_regs[c_arg]);
1586         float_args++;
1587         break;
1588 
1589       case T_DOUBLE:
1590         assert( i + 1 < total_in_args &&
1591                 in_sig_bt[i + 1] == T_VOID &&
1592                 out_sig_bt[c_arg + 1] == T_VOID, "bad arg list");
1593         __ double_move(in_regs[i], out_regs[c_arg]);
1594         float_args++;
1595         break;
1596 
1597       case T_LONG :
1598         __ long_move(in_regs[i], out_regs[c_arg]);
1599         int_args++;
1600         break;
1601 
1602       case T_ADDRESS:
1603         assert(false, "found T_ADDRESS in java args");
1604         break;
1605 
1606       default:
1607         __ move32_64(in_regs[i], out_regs[c_arg]);
1608         int_args++;
1609     }
1610   }
1611 
1612   // point c_arg at the first arg that is already loaded in case we
1613   // need to spill before we call out
1614   int c_arg = total_c_args - total_in_args;
1615 
1616   // Pre-load a static method's oop into c_rarg1.
1617   if (method->is_static()) {
1618 
1619     //  load oop into a register
1620     __ movoop(c_rarg1,
1621               JNIHandles::make_local(method->method_holder()->java_mirror()));
1622 
1623     // Now handlize the static class mirror it's known not-null.
1624     __ sd(c_rarg1, Address(sp, klass_offset));
1625     map->set_oop(VMRegImpl::stack2reg(klass_slot_offset));
1626 
1627     // Now get the handle
1628     __ la(c_rarg1, Address(sp, klass_offset));
1629     // and protect the arg if we must spill
1630     c_arg--;
1631   }
1632 
1633   // Change state to native (we save the return address in the thread, since it might not
1634   // be pushed on the stack when we do a stack traversal).
1635   // We use the same pc/oopMap repeatedly when we call out
1636 
1637   Label native_return;
1638   __ set_last_Java_frame(sp, noreg, native_return, t0);
1639 
1640   Label dtrace_method_entry, dtrace_method_entry_done;
1641   if (DTraceMethodProbes) {
1642     __ j(dtrace_method_entry);
1643     __ bind(dtrace_method_entry_done);
1644   }
1645 
1646   // RedefineClasses() tracing support for obsolete method entry
1647   if (log_is_enabled(Trace, redefine, class, obsolete)) {
1648     // protect the args we've loaded
1649     save_args(masm, total_c_args, c_arg, out_regs);
1650     __ mov_metadata(c_rarg1, method());
1651     __ call_VM_leaf(
1652       CAST_FROM_FN_PTR(address, SharedRuntime::rc_trace_method_entry),
1653       xthread, c_rarg1);
1654     restore_args(masm, total_c_args, c_arg, out_regs);
1655   }
1656 
1657   // Lock a synchronized method
1658 
1659   // Register definitions used by locking and unlocking
1660 
1661   const Register swap_reg = x10;
1662   const Register obj_reg  = x9;  // Will contain the oop
1663   const Register lock_reg = x30;  // Address of compiler lock object (BasicLock)
1664   const Register old_hdr  = x30;  // value of old header at unlock time
1665   const Register lock_tmp = x31;  // Temporary used by lightweight_lock/unlock
1666   const Register tmp      = ra;
1667 
1668   Label slow_path_lock;
1669   Label lock_done;
1670 
1671   if (method->is_synchronized()) {
1672     Label count;
1673 
1674     const int mark_word_offset = BasicLock::displaced_header_offset_in_bytes();
1675 
1676     // Get the handle (the 2nd argument)
1677     __ mv(oop_handle_reg, c_rarg1);
1678 
1679     // Get address of the box
1680 
1681     __ la(lock_reg, Address(sp, lock_slot_offset * VMRegImpl::stack_slot_size));
1682 
1683     // Load the oop from the handle
1684     __ ld(obj_reg, Address(oop_handle_reg, 0));
1685 
1686     if (LockingMode == LM_MONITOR) {
1687       __ j(slow_path_lock);
1688     } else if (LockingMode == LM_LEGACY) {
1689       // Load (object->mark() | 1) into swap_reg % x10
1690       __ ld(t0, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
1691       __ ori(swap_reg, t0, 1);
1692 
1693       // Save (object->mark() | 1) into BasicLock's displaced header
1694       __ sd(swap_reg, Address(lock_reg, mark_word_offset));
1695 
1696       // src -> dest if dest == x10 else x10 <- dest
1697       __ cmpxchg_obj_header(x10, lock_reg, obj_reg, lock_tmp, count, /*fallthrough*/nullptr);
1698 
1699       // Test if the oopMark is an obvious stack pointer, i.e.,
1700       //  1) (mark & 3) == 0, and
1701       //  2) sp <= mark < mark + os::pagesize()
1702       // These 3 tests can be done by evaluating the following
1703       // expression: ((mark - sp) & (3 - os::vm_page_size())),
1704       // assuming both stack pointer and pagesize have their
1705       // least significant 2 bits clear.
1706       // NOTE: the oopMark is in swap_reg % 10 as the result of cmpxchg
1707 
1708       __ sub(swap_reg, swap_reg, sp);
1709       __ andi(swap_reg, swap_reg, 3 - (int)os::vm_page_size());
1710 
1711       // Save the test result, for recursive case, the result is zero
1712       __ sd(swap_reg, Address(lock_reg, mark_word_offset));
1713       __ bnez(swap_reg, slow_path_lock);
1714     } else {
1715       assert(LockingMode == LM_LIGHTWEIGHT, "must be");
1716       __ lightweight_lock(obj_reg, swap_reg, tmp, lock_tmp, slow_path_lock);
1717     }
1718 
1719     __ bind(count);
1720     __ increment(Address(xthread, JavaThread::held_monitor_count_offset()));
1721 
1722     // Slow path will re-enter here
1723     __ bind(lock_done);
1724   }
1725 
1726 
1727   // Finally just about ready to make the JNI call
1728 
1729   // get JNIEnv* which is first argument to native
1730   __ la(c_rarg0, Address(xthread, in_bytes(JavaThread::jni_environment_offset())));
1731 
1732   // Now set thread in native
1733   __ la(t1, Address(xthread, JavaThread::thread_state_offset()));
1734   __ mv(t0, _thread_in_native);
1735   __ membar(MacroAssembler::LoadStore | MacroAssembler::StoreStore);
1736   __ sw(t0, Address(t1));
1737 
1738   __ rt_call(native_func);
1739 
1740   __ bind(native_return);
1741 
1742   intptr_t return_pc = (intptr_t) __ pc();
1743   oop_maps->add_gc_map(return_pc - start, map);
1744 
1745   // Verify or restore cpu control state after JNI call
1746   __ restore_cpu_control_state_after_jni(t0);
1747 
1748   // Unpack native results.
1749   if (ret_type != T_OBJECT && ret_type != T_ARRAY) {
1750     __ cast_primitive_type(ret_type, x10);
1751   }
1752 
1753   Label safepoint_in_progress, safepoint_in_progress_done;
1754   Label after_transition;
1755 
1756   // Switch thread to "native transition" state before reading the synchronization state.
1757   // This additional state is necessary because reading and testing the synchronization
1758   // state is not atomic w.r.t. GC, as this scenario demonstrates:
1759   //     Java thread A, in _thread_in_native state, loads _not_synchronized and is preempted.
1760   //     VM thread changes sync state to synchronizing and suspends threads for GC.
1761   //     Thread A is resumed to finish this native method, but doesn't block here since it
1762   //     didn't see any synchronization is progress, and escapes.
1763   __ mv(t0, _thread_in_native_trans);
1764 
1765   __ sw(t0, Address(xthread, JavaThread::thread_state_offset()));
1766 
1767   // Force this write out before the read below
1768   if (!UseSystemMemoryBarrier) {
1769     __ membar(MacroAssembler::AnyAny);
1770   }
1771 
1772   // check for safepoint operation in progress and/or pending suspend requests
1773   {
1774     // We need an acquire here to ensure that any subsequent load of the
1775     // global SafepointSynchronize::_state flag is ordered after this load
1776     // of the thread-local polling word. We don't want this poll to
1777     // return false (i.e. not safepointing) and a later poll of the global
1778     // SafepointSynchronize::_state spuriously to return true.
1779     // This is to avoid a race when we're in a native->Java transition
1780     // racing the code which wakes up from a safepoint.
1781 
1782     __ safepoint_poll(safepoint_in_progress, true /* at_return */, true /* acquire */, false /* in_nmethod */);
1783     __ lwu(t0, Address(xthread, JavaThread::suspend_flags_offset()));
1784     __ bnez(t0, safepoint_in_progress);
1785     __ bind(safepoint_in_progress_done);
1786   }
1787 
1788   // change thread state
1789   __ la(t1, Address(xthread, JavaThread::thread_state_offset()));
1790   __ mv(t0, _thread_in_Java);
1791   __ membar(MacroAssembler::LoadStore | MacroAssembler::StoreStore);
1792   __ sw(t0, Address(t1));
1793   __ bind(after_transition);
1794 
1795   Label reguard;
1796   Label reguard_done;
1797   __ lbu(t0, Address(xthread, JavaThread::stack_guard_state_offset()));
1798   __ mv(t1, StackOverflow::stack_guard_yellow_reserved_disabled);
1799   __ beq(t0, t1, reguard);
1800   __ bind(reguard_done);
1801 
1802   // native result if any is live
1803 
1804   // Unlock
1805   Label unlock_done;
1806   Label slow_path_unlock;
1807   if (method->is_synchronized()) {
1808 
1809     // Get locked oop from the handle we passed to jni
1810     __ ld(obj_reg, Address(oop_handle_reg, 0));
1811 
1812     Label done, not_recursive;
1813 
1814     if (LockingMode == LM_LEGACY) {
1815       // Simple recursive lock?
1816       __ ld(t0, Address(sp, lock_slot_offset * VMRegImpl::stack_slot_size));
1817       __ bnez(t0, not_recursive);
1818       __ decrement(Address(xthread, JavaThread::held_monitor_count_offset()));
1819       __ j(done);
1820     }
1821 
1822     __ bind(not_recursive);
1823 
1824     // Must save x10 if if it is live now because cmpxchg must use it
1825     if (ret_type != T_FLOAT && ret_type != T_DOUBLE && ret_type != T_VOID) {
1826       save_native_result(masm, ret_type, stack_slots);
1827     }
1828 
1829     if (LockingMode == LM_MONITOR) {
1830       __ j(slow_path_unlock);
1831     } else if (LockingMode == LM_LEGACY) {
1832       // get address of the stack lock
1833       __ la(x10, Address(sp, lock_slot_offset * VMRegImpl::stack_slot_size));
1834       //  get old displaced header
1835       __ ld(old_hdr, Address(x10, 0));
1836 
1837       // Atomic swap old header if oop still contains the stack lock
1838       Label count;
1839       __ cmpxchg_obj_header(x10, old_hdr, obj_reg, lock_tmp, count, &slow_path_unlock);
1840       __ bind(count);
1841       __ decrement(Address(xthread, JavaThread::held_monitor_count_offset()));
1842     } else {
1843       assert(LockingMode == LM_LIGHTWEIGHT, "");
1844       __ lightweight_unlock(obj_reg, old_hdr, swap_reg, lock_tmp, slow_path_unlock);
1845       __ decrement(Address(xthread, JavaThread::held_monitor_count_offset()));
1846     }
1847 
1848     // slow path re-enters here
1849     __ bind(unlock_done);
1850     if (ret_type != T_FLOAT && ret_type != T_DOUBLE && ret_type != T_VOID) {
1851       restore_native_result(masm, ret_type, stack_slots);
1852     }
1853 
1854     __ bind(done);
1855   }
1856 
1857   Label dtrace_method_exit, dtrace_method_exit_done;
1858   if (DTraceMethodProbes) {
1859     __ j(dtrace_method_exit);
1860     __ bind(dtrace_method_exit_done);
1861   }
1862 
1863   __ reset_last_Java_frame(false);
1864 
1865   // Unbox oop result, e.g. JNIHandles::resolve result.
1866   if (is_reference_type(ret_type)) {
1867     __ resolve_jobject(x10, x11, x12);
1868   }
1869 
1870   if (CheckJNICalls) {
1871     // clear_pending_jni_exception_check
1872     __ sd(zr, Address(xthread, JavaThread::pending_jni_exception_check_fn_offset()));
1873   }
1874 
1875   // reset handle block
1876   __ ld(x12, Address(xthread, JavaThread::active_handles_offset()));
1877   __ sd(zr, Address(x12, JNIHandleBlock::top_offset()));
1878 
1879   __ leave();
1880 
1881   // Any exception pending?
1882   Label exception_pending;
1883   __ ld(t0, Address(xthread, in_bytes(Thread::pending_exception_offset())));
1884   __ bnez(t0, exception_pending);
1885 
1886   // We're done
1887   __ ret();
1888 
1889   // Unexpected paths are out of line and go here
1890 
1891   // forward the exception
1892   __ bind(exception_pending);
1893 
1894   // and forward the exception
1895   __ far_jump(RuntimeAddress(StubRoutines::forward_exception_entry()));
1896 
1897   // Slow path locking & unlocking
1898   if (method->is_synchronized()) {
1899 
1900     __ block_comment("Slow path lock {");
1901     __ bind(slow_path_lock);
1902 
1903     // has last_Java_frame setup. No exceptions so do vanilla call not call_VM
1904     // args are (oop obj, BasicLock* lock, JavaThread* thread)
1905 
1906     // protect the args we've loaded
1907     save_args(masm, total_c_args, c_arg, out_regs);
1908 
1909     __ mv(c_rarg0, obj_reg);
1910     __ mv(c_rarg1, lock_reg);
1911     __ mv(c_rarg2, xthread);
1912 
1913     // Not a leaf but we have last_Java_frame setup as we want
1914     __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_locking_C), 3);
1915     restore_args(masm, total_c_args, c_arg, out_regs);
1916 
1917 #ifdef ASSERT
1918     { Label L;
1919       __ ld(t0, Address(xthread, in_bytes(Thread::pending_exception_offset())));
1920       __ beqz(t0, L);
1921       __ stop("no pending exception allowed on exit from monitorenter");
1922       __ bind(L);
1923     }
1924 #endif
1925     __ j(lock_done);
1926 
1927     __ block_comment("} Slow path lock");
1928 
1929     __ block_comment("Slow path unlock {");
1930     __ bind(slow_path_unlock);
1931 
1932     if (ret_type == T_FLOAT || ret_type == T_DOUBLE) {
1933       save_native_result(masm, ret_type, stack_slots);
1934     }
1935 
1936     __ mv(c_rarg2, xthread);
1937     __ la(c_rarg1, Address(sp, lock_slot_offset * VMRegImpl::stack_slot_size));
1938     __ mv(c_rarg0, obj_reg);
1939 
1940     // Save pending exception around call to VM (which contains an EXCEPTION_MARK)
1941     // NOTE that obj_reg == x9 currently
1942     __ ld(x9, Address(xthread, in_bytes(Thread::pending_exception_offset())));
1943     __ sd(zr, Address(xthread, in_bytes(Thread::pending_exception_offset())));
1944 
1945     __ rt_call(CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C));
1946 
1947 #ifdef ASSERT
1948     {
1949       Label L;
1950       __ ld(t0, Address(xthread, in_bytes(Thread::pending_exception_offset())));
1951       __ beqz(t0, L);
1952       __ stop("no pending exception allowed on exit complete_monitor_unlocking_C");
1953       __ bind(L);
1954     }
1955 #endif /* ASSERT */
1956 
1957     __ sd(x9, Address(xthread, in_bytes(Thread::pending_exception_offset())));
1958 
1959     if (ret_type == T_FLOAT || ret_type == T_DOUBLE) {
1960       restore_native_result(masm, ret_type, stack_slots);
1961     }
1962     __ j(unlock_done);
1963 
1964     __ block_comment("} Slow path unlock");
1965 
1966   } // synchronized
1967 
1968   // SLOW PATH Reguard the stack if needed
1969 
1970   __ bind(reguard);
1971   save_native_result(masm, ret_type, stack_slots);
1972   __ rt_call(CAST_FROM_FN_PTR(address, SharedRuntime::reguard_yellow_pages));
1973   restore_native_result(masm, ret_type, stack_slots);
1974   // and continue
1975   __ j(reguard_done);
1976 
1977   // SLOW PATH safepoint
1978   {
1979     __ block_comment("safepoint {");
1980     __ bind(safepoint_in_progress);
1981 
1982     // Don't use call_VM as it will see a possible pending exception and forward it
1983     // and never return here preventing us from clearing _last_native_pc down below.
1984     //
1985     save_native_result(masm, ret_type, stack_slots);
1986     __ mv(c_rarg0, xthread);
1987 #ifndef PRODUCT
1988     assert(frame::arg_reg_save_area_bytes == 0, "not expecting frame reg save area");
1989 #endif
1990     __ rt_call(CAST_FROM_FN_PTR(address, JavaThread::check_special_condition_for_native_trans));
1991 
1992     // Restore any method result value
1993     restore_native_result(masm, ret_type, stack_slots);
1994 
1995     __ j(safepoint_in_progress_done);
1996     __ block_comment("} safepoint");
1997   }
1998 
1999   // SLOW PATH dtrace support
2000   if (DTraceMethodProbes) {
2001     {
2002       __ block_comment("dtrace entry {");
2003       __ bind(dtrace_method_entry);
2004 
2005       // We have all of the arguments setup at this point. We must not touch any register
2006       // argument registers at this point (what if we save/restore them there are no oop?
2007 
2008       save_args(masm, total_c_args, c_arg, out_regs);
2009       __ mov_metadata(c_rarg1, method());
2010       __ call_VM_leaf(
2011         CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_entry),
2012         xthread, c_rarg1);
2013       restore_args(masm, total_c_args, c_arg, out_regs);
2014       __ j(dtrace_method_entry_done);
2015       __ block_comment("} dtrace entry");
2016     }
2017 
2018     {
2019       __ block_comment("dtrace exit {");
2020       __ bind(dtrace_method_exit);
2021       save_native_result(masm, ret_type, stack_slots);
2022       __ mov_metadata(c_rarg1, method());
2023       __ call_VM_leaf(
2024            CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit),
2025            xthread, c_rarg1);
2026       restore_native_result(masm, ret_type, stack_slots);
2027       __ j(dtrace_method_exit_done);
2028       __ block_comment("} dtrace exit");
2029     }
2030   }
2031 
2032   __ flush();
2033 
2034   nmethod *nm = nmethod::new_native_nmethod(method,
2035                                             compile_id,
2036                                             masm->code(),
2037                                             vep_offset,
2038                                             frame_complete,
2039                                             stack_slots / VMRegImpl::slots_per_word,
2040                                             (is_static ? in_ByteSize(klass_offset) : in_ByteSize(receiver_offset)),
2041                                             in_ByteSize(lock_slot_offset*VMRegImpl::stack_slot_size),
2042                                             oop_maps);
2043   assert(nm != nullptr, "create native nmethod fail!");
2044   return nm;
2045 }
2046 
2047 // this function returns the adjust size (in number of words) to a c2i adapter
2048 // activation for use during deoptimization
2049 int Deoptimization::last_frame_adjust(int callee_parameters, int callee_locals) {
2050   assert(callee_locals >= callee_parameters,
2051          "test and remove; got more parms than locals");
2052   if (callee_locals < callee_parameters) {
2053     return 0;                   // No adjustment for negative locals
2054   }
2055   int diff = (callee_locals - callee_parameters) * Interpreter::stackElementWords;
2056   // diff is counted in stack words
2057   return align_up(diff, 2);
2058 }
2059 
2060 //------------------------------generate_deopt_blob----------------------------
2061 void SharedRuntime::generate_deopt_blob() {
2062   // Allocate space for the code
2063   ResourceMark rm;
2064   // Setup code generation tools
2065   int pad = 0;
2066 #if INCLUDE_JVMCI
2067   if (EnableJVMCI) {
2068     pad += 512; // Increase the buffer size when compiling for JVMCI
2069   }
2070 #endif
2071   CodeBuffer buffer("deopt_blob", 2048 + pad, 1024);
2072   MacroAssembler* masm = new MacroAssembler(&buffer);
2073   int frame_size_in_words = -1;
2074   OopMap* map = nullptr;
2075   OopMapSet *oop_maps = new OopMapSet();
2076   assert_cond(masm != nullptr && oop_maps != nullptr);
2077   RegisterSaver reg_saver(COMPILER2_OR_JVMCI != 0);
2078 
2079   // -------------
2080   // This code enters when returning to a de-optimized nmethod.  A return
2081   // address has been pushed on the stack, and return values are in
2082   // registers.
2083   // If we are doing a normal deopt then we were called from the patched
2084   // nmethod from the point we returned to the nmethod. So the return
2085   // address on the stack is wrong by NativeCall::instruction_size
2086   // We will adjust the value so it looks like we have the original return
2087   // address on the stack (like when we eagerly deoptimized).
2088   // In the case of an exception pending when deoptimizing, we enter
2089   // with a return address on the stack that points after the call we patched
2090   // into the exception handler. We have the following register state from,
2091   // e.g., the forward exception stub (see stubGenerator_riscv.cpp).
2092   //    x10: exception oop
2093   //    x9: exception handler
2094   //    x13: throwing pc
2095   // So in this case we simply jam x13 into the useless return address and
2096   // the stack looks just like we want.
2097   //
2098   // At this point we need to de-opt.  We save the argument return
2099   // registers.  We call the first C routine, fetch_unroll_info().  This
2100   // routine captures the return values and returns a structure which
2101   // describes the current frame size and the sizes of all replacement frames.
2102   // The current frame is compiled code and may contain many inlined
2103   // functions, each with their own JVM state.  We pop the current frame, then
2104   // push all the new frames.  Then we call the C routine unpack_frames() to
2105   // populate these frames.  Finally unpack_frames() returns us the new target
2106   // address.  Notice that callee-save registers are BLOWN here; they have
2107   // already been captured in the vframeArray at the time the return PC was
2108   // patched.
2109   address start = __ pc();
2110   Label cont;
2111 
2112   // Prolog for non exception case!
2113 
2114   // Save everything in sight.
2115   map = reg_saver.save_live_registers(masm, 0, &frame_size_in_words);
2116 
2117   // Normal deoptimization.  Save exec mode for unpack_frames.
2118   __ mv(xcpool, Deoptimization::Unpack_deopt); // callee-saved
2119   __ j(cont);
2120 
2121   int reexecute_offset = __ pc() - start;
2122 #if INCLUDE_JVMCI && !defined(COMPILER1)
2123   if (EnableJVMCI && UseJVMCICompiler) {
2124     // JVMCI does not use this kind of deoptimization
2125     __ should_not_reach_here();
2126   }
2127 #endif
2128 
2129   // Reexecute case
2130   // return address is the pc describes what bci to do re-execute at
2131 
2132   // No need to update map as each call to save_live_registers will produce identical oopmap
2133   (void) reg_saver.save_live_registers(masm, 0, &frame_size_in_words);
2134 
2135   __ mv(xcpool, Deoptimization::Unpack_reexecute); // callee-saved
2136   __ j(cont);
2137 
2138 #if INCLUDE_JVMCI
2139   Label after_fetch_unroll_info_call;
2140   int implicit_exception_uncommon_trap_offset = 0;
2141   int uncommon_trap_offset = 0;
2142 
2143   if (EnableJVMCI) {
2144     implicit_exception_uncommon_trap_offset = __ pc() - start;
2145 
2146     __ ld(ra, Address(xthread, in_bytes(JavaThread::jvmci_implicit_exception_pc_offset())));
2147     __ sd(zr, Address(xthread, in_bytes(JavaThread::jvmci_implicit_exception_pc_offset())));
2148 
2149     uncommon_trap_offset = __ pc() - start;
2150 
2151     // Save everything in sight.
2152     reg_saver.save_live_registers(masm, 0, &frame_size_in_words);
2153     // fetch_unroll_info needs to call last_java_frame()
2154     Label retaddr;
2155     __ set_last_Java_frame(sp, noreg, retaddr, t0);
2156 
2157     __ lw(c_rarg1, Address(xthread, in_bytes(JavaThread::pending_deoptimization_offset())));
2158     __ mv(t0, -1);
2159     __ sw(t0, Address(xthread, in_bytes(JavaThread::pending_deoptimization_offset())));
2160 
2161     __ mv(xcpool, Deoptimization::Unpack_reexecute);
2162     __ mv(c_rarg0, xthread);
2163     __ orrw(c_rarg2, zr, xcpool); // exec mode
2164     __ rt_call(CAST_FROM_FN_PTR(address, Deoptimization::uncommon_trap));
2165     __ bind(retaddr);
2166     oop_maps->add_gc_map( __ pc()-start, map->deep_copy());
2167 
2168     __ reset_last_Java_frame(false);
2169 
2170     __ j(after_fetch_unroll_info_call);
2171   } // EnableJVMCI
2172 #endif // INCLUDE_JVMCI
2173 
2174   int exception_offset = __ pc() - start;
2175 
2176   // Prolog for exception case
2177 
2178   // all registers are dead at this entry point, except for x10, and
2179   // x13 which contain the exception oop and exception pc
2180   // respectively.  Set them in TLS and fall thru to the
2181   // unpack_with_exception_in_tls entry point.
2182 
2183   __ sd(x13, Address(xthread, JavaThread::exception_pc_offset()));
2184   __ sd(x10, Address(xthread, JavaThread::exception_oop_offset()));
2185 
2186   int exception_in_tls_offset = __ pc() - start;
2187 
2188   // new implementation because exception oop is now passed in JavaThread
2189 
2190   // Prolog for exception case
2191   // All registers must be preserved because they might be used by LinearScan
2192   // Exceptiop oop and throwing PC are passed in JavaThread
2193   // tos: stack at point of call to method that threw the exception (i.e. only
2194   // args are on the stack, no return address)
2195 
2196   // The return address pushed by save_live_registers will be patched
2197   // later with the throwing pc. The correct value is not available
2198   // now because loading it from memory would destroy registers.
2199 
2200   // NB: The SP at this point must be the SP of the method that is
2201   // being deoptimized.  Deoptimization assumes that the frame created
2202   // here by save_live_registers is immediately below the method's SP.
2203   // This is a somewhat fragile mechanism.
2204 
2205   // Save everything in sight.
2206   map = reg_saver.save_live_registers(masm, 0, &frame_size_in_words);
2207 
2208   // Now it is safe to overwrite any register
2209 
2210   // Deopt during an exception.  Save exec mode for unpack_frames.
2211   __ mv(xcpool, Deoptimization::Unpack_exception); // callee-saved
2212 
2213   // load throwing pc from JavaThread and patch it as the return address
2214   // of the current frame. Then clear the field in JavaThread
2215 
2216   __ ld(x13, Address(xthread, JavaThread::exception_pc_offset()));
2217   __ sd(x13, Address(fp, frame::return_addr_offset * wordSize));
2218   __ sd(zr, Address(xthread, JavaThread::exception_pc_offset()));
2219 
2220 #ifdef ASSERT
2221   // verify that there is really an exception oop in JavaThread
2222   __ ld(x10, Address(xthread, JavaThread::exception_oop_offset()));
2223   __ verify_oop(x10);
2224 
2225   // verify that there is no pending exception
2226   Label no_pending_exception;
2227   __ ld(t0, Address(xthread, Thread::pending_exception_offset()));
2228   __ beqz(t0, no_pending_exception);
2229   __ stop("must not have pending exception here");
2230   __ bind(no_pending_exception);
2231 #endif
2232 
2233   __ bind(cont);
2234 
2235   // Call C code.  Need thread and this frame, but NOT official VM entry
2236   // crud.  We cannot block on this call, no GC can happen.
2237   //
2238   // UnrollBlock* fetch_unroll_info(JavaThread* thread)
2239 
2240   // fetch_unroll_info needs to call last_java_frame().
2241 
2242   Label retaddr;
2243   __ set_last_Java_frame(sp, noreg, retaddr, t0);
2244 #ifdef ASSERT
2245   {
2246     Label L;
2247     __ ld(t0, Address(xthread,
2248                               JavaThread::last_Java_fp_offset()));
2249     __ beqz(t0, L);
2250     __ stop("SharedRuntime::generate_deopt_blob: last_Java_fp not cleared");
2251     __ bind(L);
2252   }
2253 #endif // ASSERT
2254   __ mv(c_rarg0, xthread);
2255   __ mv(c_rarg1, xcpool);
2256   __ rt_call(CAST_FROM_FN_PTR(address, Deoptimization::fetch_unroll_info));
2257   __ bind(retaddr);
2258 
2259   // Need to have an oopmap that tells fetch_unroll_info where to
2260   // find any register it might need.
2261   oop_maps->add_gc_map(__ pc() - start, map);
2262 
2263   __ reset_last_Java_frame(false);
2264 
2265 #if INCLUDE_JVMCI
2266   if (EnableJVMCI) {
2267     __ bind(after_fetch_unroll_info_call);
2268   }
2269 #endif
2270 
2271   // Load UnrollBlock* into x15
2272   __ mv(x15, x10);
2273 
2274   __ lwu(xcpool, Address(x15, Deoptimization::UnrollBlock::unpack_kind_offset()));
2275   Label noException;
2276   __ mv(t0, Deoptimization::Unpack_exception);
2277   __ bne(xcpool, t0, noException); // Was exception pending?
2278   __ ld(x10, Address(xthread, JavaThread::exception_oop_offset()));
2279   __ ld(x13, Address(xthread, JavaThread::exception_pc_offset()));
2280   __ sd(zr, Address(xthread, JavaThread::exception_oop_offset()));
2281   __ sd(zr, Address(xthread, JavaThread::exception_pc_offset()));
2282 
2283   __ verify_oop(x10);
2284 
2285   // Overwrite the result registers with the exception results.
2286   __ sd(x10, Address(sp, reg_saver.reg_offset_in_bytes(x10)));
2287 
2288   __ bind(noException);
2289 
2290   // Only register save data is on the stack.
2291   // Now restore the result registers.  Everything else is either dead
2292   // or captured in the vframeArray.
2293 
2294   // Restore fp result register
2295   __ fld(f10, Address(sp, reg_saver.freg_offset_in_bytes(f10)));
2296   // Restore integer result register
2297   __ ld(x10, Address(sp, reg_saver.reg_offset_in_bytes(x10)));
2298 
2299   // Pop all of the register save area off the stack
2300   __ add(sp, sp, frame_size_in_words * wordSize);
2301 
2302   // All of the register save area has been popped of the stack. Only the
2303   // return address remains.
2304 
2305   // Pop all the frames we must move/replace.
2306   //
2307   // Frame picture (youngest to oldest)
2308   // 1: self-frame (no frame link)
2309   // 2: deopting frame  (no frame link)
2310   // 3: caller of deopting frame (could be compiled/interpreted).
2311   //
2312   // Note: by leaving the return address of self-frame on the stack
2313   // and using the size of frame 2 to adjust the stack
2314   // when we are done the return to frame 3 will still be on the stack.
2315 
2316   // Pop deoptimized frame
2317   __ lwu(x12, Address(x15, Deoptimization::UnrollBlock::size_of_deoptimized_frame_offset()));
2318   __ sub(x12, x12, 2 * wordSize);
2319   __ add(sp, sp, x12);
2320   __ ld(fp, Address(sp, 0));
2321   __ ld(ra, Address(sp, wordSize));
2322   __ addi(sp, sp, 2 * wordSize);
2323   // RA should now be the return address to the caller (3)
2324 
2325 #ifdef ASSERT
2326   // Compilers generate code that bang the stack by as much as the
2327   // interpreter would need. So this stack banging should never
2328   // trigger a fault. Verify that it does not on non product builds.
2329   __ lwu(x9, Address(x15, Deoptimization::UnrollBlock::total_frame_sizes_offset()));
2330   __ bang_stack_size(x9, x12);
2331 #endif
2332   // Load address of array of frame pcs into x12
2333   __ ld(x12, Address(x15, Deoptimization::UnrollBlock::frame_pcs_offset()));
2334 
2335   // Load address of array of frame sizes into x14
2336   __ ld(x14, Address(x15, Deoptimization::UnrollBlock::frame_sizes_offset()));
2337 
2338   // Load counter into x13
2339   __ lwu(x13, Address(x15, Deoptimization::UnrollBlock::number_of_frames_offset()));
2340 
2341   // Now adjust the caller's stack to make up for the extra locals
2342   // but record the original sp so that we can save it in the skeletal interpreter
2343   // frame and the stack walking of interpreter_sender will get the unextended sp
2344   // value and not the "real" sp value.
2345 
2346   const Register sender_sp = x16;
2347 
2348   __ mv(sender_sp, sp);
2349   __ lwu(x9, Address(x15,
2350                      Deoptimization::UnrollBlock::
2351                      caller_adjustment_offset()));
2352   __ sub(sp, sp, x9);
2353 
2354   // Push interpreter frames in a loop
2355   __ mv(t0, 0xDEADDEAD);               // Make a recognizable pattern
2356   __ mv(t1, t0);
2357   Label loop;
2358   __ bind(loop);
2359   __ ld(x9, Address(x14, 0));          // Load frame size
2360   __ addi(x14, x14, wordSize);
2361   __ sub(x9, x9, 2 * wordSize);        // We'll push pc and fp by hand
2362   __ ld(ra, Address(x12, 0));          // Load pc
2363   __ addi(x12, x12, wordSize);
2364   __ enter();                          // Save old & set new fp
2365   __ sub(sp, sp, x9);                  // Prolog
2366   // This value is corrected by layout_activation_impl
2367   __ sd(zr, Address(fp, frame::interpreter_frame_last_sp_offset * wordSize));
2368   __ sd(sender_sp, Address(fp, frame::interpreter_frame_sender_sp_offset * wordSize)); // Make it walkable
2369   __ mv(sender_sp, sp);                // Pass sender_sp to next frame
2370   __ addi(x13, x13, -1);               // Decrement counter
2371   __ bnez(x13, loop);
2372 
2373     // Re-push self-frame
2374   __ ld(ra, Address(x12));
2375   __ enter();
2376 
2377   // Allocate a full sized register save area.  We subtract 2 because
2378   // enter() just pushed 2 words
2379   __ sub(sp, sp, (frame_size_in_words - 2) * wordSize);
2380 
2381   // Restore frame locals after moving the frame
2382   __ fsd(f10, Address(sp, reg_saver.freg_offset_in_bytes(f10)));
2383   __ sd(x10, Address(sp, reg_saver.reg_offset_in_bytes(x10)));
2384 
2385   // Call C code.  Need thread but NOT official VM entry
2386   // crud.  We cannot block on this call, no GC can happen.  Call should
2387   // restore return values to their stack-slots with the new SP.
2388   //
2389   // void Deoptimization::unpack_frames(JavaThread* thread, int exec_mode)
2390 
2391   // Use fp because the frames look interpreted now
2392   // Don't need the precise return PC here, just precise enough to point into this code blob.
2393   address the_pc = __ pc();
2394   __ set_last_Java_frame(sp, fp, the_pc, t0);
2395 
2396   __ mv(c_rarg0, xthread);
2397   __ mv(c_rarg1, xcpool); // second arg: exec_mode
2398   __ rt_call(CAST_FROM_FN_PTR(address, Deoptimization::unpack_frames));
2399 
2400   // Set an oopmap for the call site
2401   // Use the same PC we used for the last java frame
2402   oop_maps->add_gc_map(the_pc - start,
2403                        new OopMap(frame_size_in_words, 0));
2404 
2405   // Clear fp AND pc
2406   __ reset_last_Java_frame(true);
2407 
2408   // Collect return values
2409   __ fld(f10, Address(sp, reg_saver.freg_offset_in_bytes(f10)));
2410   __ ld(x10, Address(sp, reg_saver.reg_offset_in_bytes(x10)));
2411 
2412   // Pop self-frame.
2413   __ leave();                           // Epilog
2414 
2415   // Jump to interpreter
2416   __ ret();
2417 
2418   // Make sure all code is generated
2419   masm->flush();
2420 
2421   _deopt_blob = DeoptimizationBlob::create(&buffer, oop_maps, 0, exception_offset, reexecute_offset, frame_size_in_words);
2422   assert(_deopt_blob != nullptr, "create deoptimization blob fail!");
2423   _deopt_blob->set_unpack_with_exception_in_tls_offset(exception_in_tls_offset);
2424 #if INCLUDE_JVMCI
2425   if (EnableJVMCI) {
2426     _deopt_blob->set_uncommon_trap_offset(uncommon_trap_offset);
2427     _deopt_blob->set_implicit_exception_uncommon_trap_offset(implicit_exception_uncommon_trap_offset);
2428   }
2429 #endif
2430 }
2431 
2432 // Number of stack slots between incoming argument block and the start of
2433 // a new frame. The PROLOG must add this many slots to the stack. The
2434 // EPILOG must remove this many slots.
2435 // RISCV needs two words for RA (return address) and FP (frame pointer).
2436 uint SharedRuntime::in_preserve_stack_slots() {
2437   return 2 * VMRegImpl::slots_per_word;
2438 }
2439 
2440 uint SharedRuntime::out_preserve_stack_slots() {
2441   return 0;
2442 }
2443 
2444 #ifdef COMPILER2
2445 //------------------------------generate_uncommon_trap_blob--------------------
2446 void SharedRuntime::generate_uncommon_trap_blob() {
2447   // Allocate space for the code
2448   ResourceMark rm;
2449   // Setup code generation tools
2450   CodeBuffer buffer("uncommon_trap_blob", 2048, 1024);
2451   MacroAssembler* masm = new MacroAssembler(&buffer);
2452   assert_cond(masm != nullptr);
2453 
2454   assert(SimpleRuntimeFrame::framesize % 4 == 0, "sp not 16-byte aligned");
2455 
2456   address start = __ pc();
2457 
2458   // Push self-frame.  We get here with a return address in RA
2459   // and sp should be 16 byte aligned
2460   // push fp and retaddr by hand
2461   __ addi(sp, sp, -2 * wordSize);
2462   __ sd(ra, Address(sp, wordSize));
2463   __ sd(fp, Address(sp, 0));
2464   // we don't expect an arg reg save area
2465 #ifndef PRODUCT
2466   assert(frame::arg_reg_save_area_bytes == 0, "not expecting frame reg save area");
2467 #endif
2468   // compiler left unloaded_class_index in j_rarg0 move to where the
2469   // runtime expects it.
2470   __ sign_extend(c_rarg1, j_rarg0, 32);
2471 
2472   // we need to set the past SP to the stack pointer of the stub frame
2473   // and the pc to the address where this runtime call will return
2474   // although actually any pc in this code blob will do).
2475   Label retaddr;
2476   __ set_last_Java_frame(sp, noreg, retaddr, t0);
2477 
2478   // Call C code.  Need thread but NOT official VM entry
2479   // crud.  We cannot block on this call, no GC can happen.  Call should
2480   // capture callee-saved registers as well as return values.
2481   //
2482   // UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index, jint exec_mode)
2483   //
2484   // n.b. 3 gp args, 0 fp args, integral return type
2485 
2486   __ mv(c_rarg0, xthread);
2487   __ mv(c_rarg2, Deoptimization::Unpack_uncommon_trap);
2488   __ rt_call(CAST_FROM_FN_PTR(address, Deoptimization::uncommon_trap));
2489   __ bind(retaddr);
2490 
2491   // Set an oopmap for the call site
2492   OopMapSet* oop_maps = new OopMapSet();
2493   OopMap* map = new OopMap(SimpleRuntimeFrame::framesize, 0);
2494   assert_cond(oop_maps != nullptr && map != nullptr);
2495 
2496   // location of fp is known implicitly by the frame sender code
2497 
2498   oop_maps->add_gc_map(__ pc() - start, map);
2499 
2500   __ reset_last_Java_frame(false);
2501 
2502   // move UnrollBlock* into x14
2503   __ mv(x14, x10);
2504 
2505 #ifdef ASSERT
2506   { Label L;
2507     __ lwu(t0, Address(x14, Deoptimization::UnrollBlock::unpack_kind_offset()));
2508     __ mv(t1, Deoptimization::Unpack_uncommon_trap);
2509     __ beq(t0, t1, L);
2510     __ stop("SharedRuntime::generate_uncommon_trap_blob: expected Unpack_uncommon_trap");
2511     __ bind(L);
2512   }
2513 #endif
2514 
2515   // Pop all the frames we must move/replace.
2516   //
2517   // Frame picture (youngest to oldest)
2518   // 1: self-frame (no frame link)
2519   // 2: deopting frame  (no frame link)
2520   // 3: caller of deopting frame (could be compiled/interpreted).
2521 
2522   __ add(sp, sp, (SimpleRuntimeFrame::framesize) << LogBytesPerInt); // Epilog!
2523 
2524   // Pop deoptimized frame (int)
2525   __ lwu(x12, Address(x14,
2526                       Deoptimization::UnrollBlock::
2527                       size_of_deoptimized_frame_offset()));
2528   __ sub(x12, x12, 2 * wordSize);
2529   __ add(sp, sp, x12);
2530   __ ld(fp, Address(sp, 0));
2531   __ ld(ra, Address(sp, wordSize));
2532   __ addi(sp, sp, 2 * wordSize);
2533   // RA should now be the return address to the caller (3) frame
2534 
2535 #ifdef ASSERT
2536   // Compilers generate code that bang the stack by as much as the
2537   // interpreter would need. So this stack banging should never
2538   // trigger a fault. Verify that it does not on non product builds.
2539   __ lwu(x11, Address(x14,
2540                       Deoptimization::UnrollBlock::
2541                       total_frame_sizes_offset()));
2542   __ bang_stack_size(x11, x12);
2543 #endif
2544 
2545   // Load address of array of frame pcs into x12 (address*)
2546   __ ld(x12, Address(x14,
2547                      Deoptimization::UnrollBlock::frame_pcs_offset()));
2548 
2549   // Load address of array of frame sizes into x15 (intptr_t*)
2550   __ ld(x15, Address(x14,
2551                      Deoptimization::UnrollBlock::
2552                      frame_sizes_offset()));
2553 
2554   // Counter
2555   __ lwu(x13, Address(x14,
2556                       Deoptimization::UnrollBlock::
2557                       number_of_frames_offset())); // (int)
2558 
2559   // Now adjust the caller's stack to make up for the extra locals but
2560   // record the original sp so that we can save it in the skeletal
2561   // interpreter frame and the stack walking of interpreter_sender
2562   // will get the unextended sp value and not the "real" sp value.
2563 
2564   const Register sender_sp = t1; // temporary register
2565 
2566   __ lwu(x11, Address(x14,
2567                       Deoptimization::UnrollBlock::
2568                       caller_adjustment_offset())); // (int)
2569   __ mv(sender_sp, sp);
2570   __ sub(sp, sp, x11);
2571 
2572   // Push interpreter frames in a loop
2573   Label loop;
2574   __ bind(loop);
2575   __ ld(x11, Address(x15, 0));       // Load frame size
2576   __ sub(x11, x11, 2 * wordSize);    // We'll push pc and fp by hand
2577   __ ld(ra, Address(x12, 0));        // Save return address
2578   __ enter();                        // and old fp & set new fp
2579   __ sub(sp, sp, x11);               // Prolog
2580   __ sd(sender_sp, Address(fp, frame::interpreter_frame_sender_sp_offset * wordSize)); // Make it walkable
2581   // This value is corrected by layout_activation_impl
2582   __ sd(zr, Address(fp, frame::interpreter_frame_last_sp_offset * wordSize));
2583   __ mv(sender_sp, sp);              // Pass sender_sp to next frame
2584   __ add(x15, x15, wordSize);        // Bump array pointer (sizes)
2585   __ add(x12, x12, wordSize);        // Bump array pointer (pcs)
2586   __ subw(x13, x13, 1);              // Decrement counter
2587   __ bgtz(x13, loop);
2588   __ ld(ra, Address(x12, 0));        // save final return address
2589   // Re-push self-frame
2590   __ enter();                        // & old fp & set new fp
2591 
2592   // Use fp because the frames look interpreted now
2593   // Save "the_pc" since it cannot easily be retrieved using the last_java_SP after we aligned SP.
2594   // Don't need the precise return PC here, just precise enough to point into this code blob.
2595   address the_pc = __ pc();
2596   __ set_last_Java_frame(sp, fp, the_pc, t0);
2597 
2598   // Call C code.  Need thread but NOT official VM entry
2599   // crud.  We cannot block on this call, no GC can happen.  Call should
2600   // restore return values to their stack-slots with the new SP.
2601   //
2602   // BasicType unpack_frames(JavaThread* thread, int exec_mode)
2603   //
2604 
2605   // n.b. 2 gp args, 0 fp args, integral return type
2606 
2607   // sp should already be aligned
2608   __ mv(c_rarg0, xthread);
2609   __ mv(c_rarg1, Deoptimization::Unpack_uncommon_trap);
2610   __ rt_call(CAST_FROM_FN_PTR(address, Deoptimization::unpack_frames));
2611 
2612   // Set an oopmap for the call site
2613   // Use the same PC we used for the last java frame
2614   oop_maps->add_gc_map(the_pc - start, new OopMap(SimpleRuntimeFrame::framesize, 0));
2615 
2616   // Clear fp AND pc
2617   __ reset_last_Java_frame(true);
2618 
2619   // Pop self-frame.
2620   __ leave();                 // Epilog
2621 
2622   // Jump to interpreter
2623   __ ret();
2624 
2625   // Make sure all code is generated
2626   masm->flush();
2627 
2628   _uncommon_trap_blob =  UncommonTrapBlob::create(&buffer, oop_maps,
2629                                                   SimpleRuntimeFrame::framesize >> 1);
2630 }
2631 #endif // COMPILER2
2632 
2633 //------------------------------generate_handler_blob------
2634 //
2635 // Generate a special Compile2Runtime blob that saves all registers,
2636 // and setup oopmap.
2637 //
2638 SafepointBlob* SharedRuntime::generate_handler_blob(address call_ptr, int poll_type) {
2639   ResourceMark rm;
2640   OopMapSet *oop_maps = new OopMapSet();
2641   assert_cond(oop_maps != nullptr);
2642   OopMap* map = nullptr;
2643 
2644   // Allocate space for the code.  Setup code generation tools.
2645   CodeBuffer buffer("handler_blob", 2048, 1024);
2646   MacroAssembler* masm = new MacroAssembler(&buffer);
2647   assert_cond(masm != nullptr);
2648 
2649   address start   = __ pc();
2650   address call_pc = nullptr;
2651   int frame_size_in_words = -1;
2652   bool cause_return = (poll_type == POLL_AT_RETURN);
2653   RegisterSaver reg_saver(poll_type == POLL_AT_VECTOR_LOOP /* save_vectors */);
2654 
2655   // Save Integer and Float registers.
2656   map = reg_saver.save_live_registers(masm, 0, &frame_size_in_words);
2657 
2658   // The following is basically a call_VM.  However, we need the precise
2659   // address of the call in order to generate an oopmap. Hence, we do all the
2660   // work ourselves.
2661 
2662   Label retaddr;
2663   __ set_last_Java_frame(sp, noreg, retaddr, t0);
2664 
2665   // The return address must always be correct so that frame constructor never
2666   // sees an invalid pc.
2667 
2668   if (!cause_return) {
2669     // overwrite the return address pushed by save_live_registers
2670     // Additionally, x18 is a callee-saved register so we can look at
2671     // it later to determine if someone changed the return address for
2672     // us!
2673     __ ld(x18, Address(xthread, JavaThread::saved_exception_pc_offset()));
2674     __ sd(x18, Address(fp, frame::return_addr_offset * wordSize));
2675   }
2676 
2677   // Do the call
2678   __ mv(c_rarg0, xthread);
2679   __ rt_call(call_ptr);
2680   __ bind(retaddr);
2681 
2682   // Set an oopmap for the call site.  This oopmap will map all
2683   // oop-registers and debug-info registers as callee-saved.  This
2684   // will allow deoptimization at this safepoint to find all possible
2685   // debug-info recordings, as well as let GC find all oops.
2686 
2687   oop_maps->add_gc_map( __ pc() - start, map);
2688 
2689   Label noException;
2690 
2691   __ reset_last_Java_frame(false);
2692 
2693   __ membar(MacroAssembler::LoadLoad | MacroAssembler::LoadStore);
2694 
2695   __ ld(t0, Address(xthread, Thread::pending_exception_offset()));
2696   __ beqz(t0, noException);
2697 
2698   // Exception pending
2699 
2700   reg_saver.restore_live_registers(masm);
2701 
2702   __ far_jump(RuntimeAddress(StubRoutines::forward_exception_entry()));
2703 
2704   // No exception case
2705   __ bind(noException);
2706 
2707   Label no_adjust, bail;
2708   if (!cause_return) {
2709     // If our stashed return pc was modified by the runtime we avoid touching it
2710     __ ld(t0, Address(fp, frame::return_addr_offset * wordSize));
2711     __ bne(x18, t0, no_adjust);
2712 
2713 #ifdef ASSERT
2714     // Verify the correct encoding of the poll we're about to skip.
2715     // See NativeInstruction::is_lwu_to_zr()
2716     __ lwu(t0, Address(x18));
2717     __ andi(t1, t0, 0b0000011);
2718     __ mv(t2, 0b0000011);
2719     __ bne(t1, t2, bail); // 0-6:0b0000011
2720     __ srli(t1, t0, 7);
2721     __ andi(t1, t1, 0b00000);
2722     __ bnez(t1, bail);    // 7-11:0b00000
2723     __ srli(t1, t0, 12);
2724     __ andi(t1, t1, 0b110);
2725     __ mv(t2, 0b110);
2726     __ bne(t1, t2, bail); // 12-14:0b110
2727 #endif
2728     // Adjust return pc forward to step over the safepoint poll instruction
2729     __ add(x18, x18, NativeInstruction::instruction_size);
2730     __ sd(x18, Address(fp, frame::return_addr_offset * wordSize));
2731   }
2732 
2733   __ bind(no_adjust);
2734   // Normal exit, restore registers and exit.
2735 
2736   reg_saver.restore_live_registers(masm);
2737   __ ret();
2738 
2739 #ifdef ASSERT
2740   __ bind(bail);
2741   __ stop("Attempting to adjust pc to skip safepoint poll but the return point is not what we expected");
2742 #endif
2743 
2744   // Make sure all code is generated
2745   masm->flush();
2746 
2747   // Fill-out other meta info
2748   return SafepointBlob::create(&buffer, oop_maps, frame_size_in_words);
2749 }
2750 
2751 //
2752 // generate_resolve_blob - call resolution (static/virtual/opt-virtual/ic-miss
2753 //
2754 // Generate a stub that calls into vm to find out the proper destination
2755 // of a java call. All the argument registers are live at this point
2756 // but since this is generic code we don't know what they are and the caller
2757 // must do any gc of the args.
2758 //
2759 RuntimeStub* SharedRuntime::generate_resolve_blob(address destination, const char* name) {
2760   assert(StubRoutines::forward_exception_entry() != nullptr, "must be generated before");
2761 
2762   // allocate space for the code
2763   ResourceMark rm;
2764 
2765   CodeBuffer buffer(name, 1000, 512);
2766   MacroAssembler* masm = new MacroAssembler(&buffer);
2767   assert_cond(masm != nullptr);
2768 
2769   int frame_size_in_words = -1;
2770   RegisterSaver reg_saver(false /* save_vectors */);
2771 
2772   OopMapSet *oop_maps = new OopMapSet();
2773   assert_cond(oop_maps != nullptr);
2774   OopMap* map = nullptr;
2775 
2776   int start = __ offset();
2777 
2778   map = reg_saver.save_live_registers(masm, 0, &frame_size_in_words);
2779 
2780   int frame_complete = __ offset();
2781 
2782   {
2783     Label retaddr;
2784     __ set_last_Java_frame(sp, noreg, retaddr, t0);
2785 
2786     __ mv(c_rarg0, xthread);
2787     __ rt_call(destination);
2788     __ bind(retaddr);
2789   }
2790 
2791   // Set an oopmap for the call site.
2792   // We need this not only for callee-saved registers, but also for volatile
2793   // registers that the compiler might be keeping live across a safepoint.
2794 
2795   oop_maps->add_gc_map( __ offset() - start, map);
2796 
2797   // x10 contains the address we are going to jump to assuming no exception got installed
2798 
2799   // clear last_Java_sp
2800   __ reset_last_Java_frame(false);
2801   // check for pending exceptions
2802   Label pending;
2803   __ ld(t0, Address(xthread, Thread::pending_exception_offset()));
2804   __ bnez(t0, pending);
2805 
2806   // get the returned Method*
2807   __ get_vm_result_2(xmethod, xthread);
2808   __ sd(xmethod, Address(sp, reg_saver.reg_offset_in_bytes(xmethod)));
2809 
2810   // x10 is where we want to jump, overwrite t0 which is saved and temporary
2811   __ sd(x10, Address(sp, reg_saver.reg_offset_in_bytes(t0)));
2812   reg_saver.restore_live_registers(masm);
2813 
2814   // We are back to the original state on entry and ready to go.
2815 
2816   __ jr(t0);
2817 
2818   // Pending exception after the safepoint
2819 
2820   __ bind(pending);
2821 
2822   reg_saver.restore_live_registers(masm);
2823 
2824   // exception pending => remove activation and forward to exception handler
2825 
2826   __ sd(zr, Address(xthread, JavaThread::vm_result_offset()));
2827 
2828   __ ld(x10, Address(xthread, Thread::pending_exception_offset()));
2829   __ far_jump(RuntimeAddress(StubRoutines::forward_exception_entry()));
2830 
2831   // -------------
2832   // make sure all code is generated
2833   masm->flush();
2834 
2835   // return the  blob
2836   return RuntimeStub::new_runtime_stub(name, &buffer, frame_complete, frame_size_in_words, oop_maps, true);
2837 }
2838 
2839 #ifdef COMPILER2
2840 //------------------------------generate_exception_blob---------------------------
2841 // creates exception blob at the end
2842 // Using exception blob, this code is jumped from a compiled method.
2843 // (see emit_exception_handler in riscv.ad file)
2844 //
2845 // Given an exception pc at a call we call into the runtime for the
2846 // handler in this method. This handler might merely restore state
2847 // (i.e. callee save registers) unwind the frame and jump to the
2848 // exception handler for the nmethod if there is no Java level handler
2849 // for the nmethod.
2850 //
2851 // This code is entered with a jmp.
2852 //
2853 // Arguments:
2854 //   x10: exception oop
2855 //   x13: exception pc
2856 //
2857 // Results:
2858 //   x10: exception oop
2859 //   x13: exception pc in caller
2860 //   destination: exception handler of caller
2861 //
2862 // Note: the exception pc MUST be at a call (precise debug information)
2863 //       Registers x10, x13, x12, x14, x15, t0 are not callee saved.
2864 //
2865 
2866 void OptoRuntime::generate_exception_blob() {
2867   assert(!OptoRuntime::is_callee_saved_register(R13_num), "");
2868   assert(!OptoRuntime::is_callee_saved_register(R10_num), "");
2869   assert(!OptoRuntime::is_callee_saved_register(R12_num), "");
2870 
2871   assert(SimpleRuntimeFrame::framesize % 4 == 0, "sp not 16-byte aligned");
2872 
2873   // Allocate space for the code
2874   ResourceMark rm;
2875   // Setup code generation tools
2876   CodeBuffer buffer("exception_blob", 2048, 1024);
2877   MacroAssembler* masm = new MacroAssembler(&buffer);
2878   assert_cond(masm != nullptr);
2879 
2880   // TODO check various assumptions made here
2881   //
2882   // make sure we do so before running this
2883 
2884   address start = __ pc();
2885 
2886   // push fp and retaddr by hand
2887   // Exception pc is 'return address' for stack walker
2888   __ addi(sp, sp, -2 * wordSize);
2889   __ sd(ra, Address(sp, wordSize));
2890   __ sd(fp, Address(sp));
2891   // there are no callee save registers and we don't expect an
2892   // arg reg save area
2893 #ifndef PRODUCT
2894   assert(frame::arg_reg_save_area_bytes == 0, "not expecting frame reg save area");
2895 #endif
2896   // Store exception in Thread object. We cannot pass any arguments to the
2897   // handle_exception call, since we do not want to make any assumption
2898   // about the size of the frame where the exception happened in.
2899   __ sd(x10, Address(xthread, JavaThread::exception_oop_offset()));
2900   __ sd(x13, Address(xthread, JavaThread::exception_pc_offset()));
2901 
2902   // This call does all the hard work.  It checks if an exception handler
2903   // exists in the method.
2904   // If so, it returns the handler address.
2905   // If not, it prepares for stack-unwinding, restoring the callee-save
2906   // registers of the frame being removed.
2907   //
2908   // address OptoRuntime::handle_exception_C(JavaThread* thread)
2909   //
2910   // n.b. 1 gp arg, 0 fp args, integral return type
2911 
2912   // the stack should always be aligned
2913   address the_pc = __ pc();
2914   __ set_last_Java_frame(sp, noreg, the_pc, t0);
2915   __ mv(c_rarg0, xthread);
2916   __ rt_call(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C));
2917 
2918   // handle_exception_C is a special VM call which does not require an explicit
2919   // instruction sync afterwards.
2920 
2921   // Set an oopmap for the call site.  This oopmap will only be used if we
2922   // are unwinding the stack.  Hence, all locations will be dead.
2923   // Callee-saved registers will be the same as the frame above (i.e.,
2924   // handle_exception_stub), since they were restored when we got the
2925   // exception.
2926 
2927   OopMapSet* oop_maps = new OopMapSet();
2928   assert_cond(oop_maps != nullptr);
2929 
2930   oop_maps->add_gc_map(the_pc - start, new OopMap(SimpleRuntimeFrame::framesize, 0));
2931 
2932   __ reset_last_Java_frame(false);
2933 
2934   // Restore callee-saved registers
2935 
2936   // fp is an implicitly saved callee saved register (i.e. the calling
2937   // convention will save restore it in prolog/epilog) Other than that
2938   // there are no callee save registers now that adapter frames are gone.
2939   // and we dont' expect an arg reg save area
2940   __ ld(fp, Address(sp));
2941   __ ld(x13, Address(sp, wordSize));
2942   __ addi(sp, sp , 2 * wordSize);
2943 
2944   // x10: exception handler
2945 
2946   // We have a handler in x10 (could be deopt blob).
2947   __ mv(t0, x10);
2948 
2949   // Get the exception oop
2950   __ ld(x10, Address(xthread, JavaThread::exception_oop_offset()));
2951   // Get the exception pc in case we are deoptimized
2952   __ ld(x14, Address(xthread, JavaThread::exception_pc_offset()));
2953 #ifdef ASSERT
2954   __ sd(zr, Address(xthread, JavaThread::exception_handler_pc_offset()));
2955   __ sd(zr, Address(xthread, JavaThread::exception_pc_offset()));
2956 #endif
2957   // Clear the exception oop so GC no longer processes it as a root.
2958   __ sd(zr, Address(xthread, JavaThread::exception_oop_offset()));
2959 
2960   // x10: exception oop
2961   // t0:  exception handler
2962   // x14: exception pc
2963   // Jump to handler
2964 
2965   __ jr(t0);
2966 
2967   // Make sure all code is generated
2968   masm->flush();
2969 
2970   // Set exception blob
2971   _exception_blob =  ExceptionBlob::create(&buffer, oop_maps, SimpleRuntimeFrame::framesize >> 1);
2972 }
2973 #endif // COMPILER2