1 /*
   2  * Copyright (c) 2008, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/assembler.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "assembler_arm.inline.hpp"
  29 #include "code/vtableStubs.hpp"
  30 #include "interp_masm_arm.hpp"
  31 #include "memory/resourceArea.hpp"
  32 #include "oops/compiledICHolder.hpp"
  33 #include "oops/instanceKlass.hpp"
  34 #include "oops/klassVtable.hpp"
  35 #include "runtime/sharedRuntime.hpp"
  36 #include "vmreg_arm.inline.hpp"
  37 #ifdef COMPILER2
  38 #include "opto/runtime.hpp"
  39 #endif
  40 
  41 // machine-dependent part of VtableStubs: create VtableStub of correct size and
  42 // initialize its code
  43 
  44 #define __ masm->
  45 
  46 #ifndef PRODUCT
  47 extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index);
  48 #endif
  49 
  50 VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
  51   // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.
  52   const int stub_code_length = code_size_limit(true);
  53   VtableStub* s = new(stub_code_length) VtableStub(true, vtable_index);
  54   // Can be NULL if there is no free space in the code cache.
  55   if (s == NULL) {
  56     return NULL;
  57   }
  58 
  59   // Count unused bytes in instruction sequences of variable size.
  60   // We add them to the computed buffer size in order to avoid
  61   // overflow in subsequently generated stubs.
  62   address   start_pc;
  63   int       slop_bytes = 0;
  64   int       slop_delta = 0;
  65 
  66   ResourceMark    rm;
  67   CodeBuffer      cb(s->entry_point(), stub_code_length);
  68   MacroAssembler* masm = new MacroAssembler(&cb);
  69 
  70 #if (!defined(PRODUCT) && defined(COMPILER2))
  71   if (CountCompiledCalls) {
  72     // Implementation required?
  73   }
  74 #endif
  75 
  76   assert(VtableStub::receiver_location() == R0->as_VMReg(), "receiver expected in R0");
  77 
  78   const Register tmp = Rtemp; // Rtemp OK, should be free at call sites
  79 
  80   address npe_addr = __ pc();
  81   __ load_klass(tmp, R0);
  82 
  83 #ifndef PRODUCT
  84   if (DebugVtables) {
  85     // Implementation required?
  86   }
  87 #endif
  88 
  89   start_pc = __ pc();
  90   { // lookup virtual method
  91     int entry_offset = in_bytes(Klass::vtable_start_offset()) + vtable_index * vtableEntry::size_in_bytes();
  92     int method_offset = vtableEntry::method_offset_in_bytes() + entry_offset;
  93 
  94     assert ((method_offset & (wordSize - 1)) == 0, "offset should be aligned");
  95     int offset_mask = AARCH64_ONLY(0xfff << LogBytesPerWord) NOT_AARCH64(0xfff);
  96     if (method_offset & ~offset_mask) {
  97       __ add(tmp, tmp, method_offset & ~offset_mask);
  98     }
  99     __ ldr(Rmethod, Address(tmp, method_offset & offset_mask));
 100   }
 101   slop_delta  = 8 - (int)(__ pc() - start_pc);
 102   slop_bytes += slop_delta;
 103   assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);
 104 
 105 #ifndef PRODUCT
 106   if (DebugVtables) {
 107     // Implementation required?
 108   }
 109 #endif
 110 
 111   address ame_addr = __ pc();
 112 #ifdef AARCH64
 113   __ ldr(tmp, Address(Rmethod, Method::from_compiled_offset()));
 114   __ br(tmp);
 115 #else
 116   __ ldr(PC, Address(Rmethod, Method::from_compiled_offset()));
 117 #endif // AARCH64
 118 
 119   masm->flush();
 120   bookkeeping(masm, tty, s, npe_addr, ame_addr, true, vtable_index, slop_bytes, 0);
 121 
 122   return s;
 123 }
 124 
 125 VtableStub* VtableStubs::create_itable_stub(int itable_index) {
 126   // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.
 127   const int stub_code_length = code_size_limit(false);
 128   VtableStub* s = new(stub_code_length) VtableStub(false, itable_index);
 129   // Can be NULL if there is no free space in the code cache.
 130   if (s == NULL) {
 131     return NULL;
 132   }
 133   // Count unused bytes in instruction sequences of variable size.
 134   // We add them to the computed buffer size in order to avoid
 135   // overflow in subsequently generated stubs.
 136   address   start_pc;
 137   int       slop_bytes = 0;
 138   int       slop_delta = 0;
 139 
 140   ResourceMark    rm;
 141   CodeBuffer      cb(s->entry_point(), stub_code_length);
 142   MacroAssembler* masm = new MacroAssembler(&cb);
 143 
 144 #if (!defined(PRODUCT) && defined(COMPILER2))
 145   if (CountCompiledCalls) {
 146     // Implementation required?
 147   }
 148 #endif
 149 
 150   assert(VtableStub::receiver_location() == R0->as_VMReg(), "receiver expected in R0");
 151 
 152   // R0-R3 / R0-R7 registers hold the arguments and cannot be spoiled
 153   const Register Rclass  = AARCH64_ONLY(R9)  NOT_AARCH64(R4);
 154   const Register Rintf   = AARCH64_ONLY(R10) NOT_AARCH64(R5);
 155   const Register Rscan   = AARCH64_ONLY(R11) NOT_AARCH64(R6);
 156 
 157   Label L_no_such_interface;
 158 
 159   assert_different_registers(Ricklass, Rclass, Rintf, Rscan, Rtemp);
 160 
 161   start_pc = __ pc();
 162 
 163   // get receiver klass (also an implicit null-check)
 164   address npe_addr = __ pc();
 165   __ load_klass(Rclass, R0);
 166 
 167   // Receiver subtype check against REFC.
 168   __ ldr(Rintf, Address(Ricklass, CompiledICHolder::holder_klass_offset()));
 169   __ lookup_interface_method(// inputs: rec. class, interface, itable index
 170                              Rclass, Rintf, noreg,
 171                              // outputs: temp reg1, temp reg2
 172                              noreg, Rscan, Rtemp,
 173                              L_no_such_interface);
 174 
 175   const ptrdiff_t  typecheckSize = __ pc() - start_pc;
 176   start_pc = __ pc();
 177 
 178   // Get Method* and entry point for compiler
 179   __ ldr(Rintf, Address(Ricklass, CompiledICHolder::holder_metadata_offset()));
 180   __ lookup_interface_method(// inputs: rec. class, interface, itable index
 181                              Rclass, Rintf, itable_index,
 182                              // outputs: temp reg1, temp reg2, temp reg3
 183                              Rmethod, Rscan, Rtemp,
 184                              L_no_such_interface);
 185 
 186   const ptrdiff_t lookupSize = __ pc() - start_pc;
 187 
 188   // Reduce "estimate" such that "padding" does not drop below 8.
 189   const ptrdiff_t estimate = 140;
 190   const ptrdiff_t codesize = typecheckSize + lookupSize;
 191   slop_delta  = (int)(estimate - codesize);
 192   slop_bytes += slop_delta;
 193   assert(slop_delta >= 0, "itable #%d: Code size estimate (%d) for lookup_interface_method too small, required: %d", itable_index, (int)estimate, (int)codesize);
 194 
 195 #ifndef PRODUCT
 196   if (DebugVtables) {
 197     // Implementation required?
 198   }
 199 #endif
 200 
 201   address ame_addr = __ pc();
 202 
 203 #ifdef AARCH64
 204   __ ldr(Rtemp, Address(Rmethod, Method::from_compiled_offset()));
 205   __ br(Rtemp);
 206 #else
 207   __ ldr(PC, Address(Rmethod, Method::from_compiled_offset()));
 208 #endif // AARCH64
 209 
 210   __ bind(L_no_such_interface);
 211   // Handle IncompatibleClassChangeError in itable stubs.
 212   // More detailed error message.
 213   // We force resolving of the call site by jumping to the "handle
 214   // wrong method" stub, and so let the interpreter runtime do all the
 215   // dirty work.
 216   assert(SharedRuntime::get_handle_wrong_method_stub() != NULL, "check initialization order");
 217   __ jump(SharedRuntime::get_handle_wrong_method_stub(), relocInfo::runtime_call_type, Rtemp);
 218 
 219   masm->flush();
 220   bookkeeping(masm, tty, s, npe_addr, ame_addr, false, itable_index, slop_bytes, 0);
 221 
 222   return s;
 223 }
 224 
 225 int VtableStub::pd_code_alignment() {
 226   // ARM32 cache line size is not an architected constant. We just align on word size.
 227   const unsigned int icache_line_size = wordSize;
 228   return icache_line_size;
 229 }