1 /*
   2  * Copyright (c) 1997, 2016, 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/macroAssembler.inline.hpp"
  27 #include "code/vtableStubs.hpp"
  28 #include "interp_masm_sparc.hpp"
  29 #include "memory/resourceArea.hpp"
  30 #include "oops/instanceKlass.hpp"
  31 #include "oops/klassVtable.hpp"
  32 #include "runtime/sharedRuntime.hpp"
  33 #include "vmreg_sparc.inline.hpp"
  34 #ifdef COMPILER2
  35 #include "opto/runtime.hpp"
  36 #endif
  37 
  38 // machine-dependent part of VtableStubs: create vtableStub of correct size and
  39 // initialize its code
  40 
  41 #define __ masm->
  42 
  43 
  44 #ifndef PRODUCT
  45 extern "C" void bad_compiled_vtable_index(JavaThread* thread, oopDesc* receiver, int index);
  46 #endif
  47 
  48 
  49 // Used by compiler only; may use only caller saved, non-argument registers
  50 // NOTE:  %%%% if any change is made to this stub make sure that the function
  51 //             pd_code_size_limit is changed to ensure the correct size for VtableStub
  52 VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
  53   const int sparc_code_length = VtableStub::pd_code_size_limit(true);
  54   VtableStub* s = new(sparc_code_length) VtableStub(true, vtable_index);
  55   // Can be NULL if there is no free space in the code cache.
  56   if (s == NULL) {
  57     return NULL;
  58   }
  59 
  60   ResourceMark rm;
  61   CodeBuffer cb(s->entry_point(), sparc_code_length);
  62   MacroAssembler* masm = new MacroAssembler(&cb);
  63 
  64 #ifndef PRODUCT
  65   if (CountCompiledCalls) {
  66     __ inc_counter(SharedRuntime::nof_megamorphic_calls_addr(), G5, G3_scratch);
  67   }
  68 #endif /* PRODUCT */
  69 
  70   assert(VtableStub::receiver_location() == O0->as_VMReg(), "receiver expected in O0");
  71 
  72   // get receiver klass
  73   address npe_addr = __ pc();
  74   __ load_klass(O0, G3_scratch);
  75 
  76   // set Method* (in case of interpreted method), and destination address
  77 #ifndef PRODUCT
  78   if (DebugVtables) {
  79     Label L;
  80     // check offset vs vtable length
  81     __ ld(G3_scratch, in_bytes(Klass::vtable_length_offset()), G5);
  82     __ cmp_and_br_short(G5, vtable_index*vtableEntry::size(), Assembler::greaterUnsigned, Assembler::pt, L);
  83     __ set(vtable_index, O2);
  84     __ call_VM(noreg, CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), O0, O2);
  85     __ bind(L);
  86   }
  87 #endif
  88 
  89   __ lookup_virtual_method(G3_scratch, vtable_index, G5_method);
  90 
  91 #ifndef PRODUCT
  92   if (DebugVtables) {
  93     Label L;
  94     __ br_notnull_short(G5_method, Assembler::pt, L);
  95     __ stop("Vtable entry is ZERO");
  96     __ bind(L);
  97   }
  98 #endif
  99 
 100   address ame_addr = __ pc();  // if the vtable entry is null, the method is abstract
 101                                // NOTE: for vtable dispatches, the vtable entry will never be null.
 102 
 103   __ ld_ptr(G5_method, in_bytes(Method::from_compiled_offset()), G3_scratch);
 104 
 105   // jump to target (either compiled code or c2iadapter)
 106   __ JMP(G3_scratch, 0);
 107   // load Method* (in case we call c2iadapter)
 108   __ delayed()->nop();
 109 
 110   masm->flush();
 111 
 112   if (PrintMiscellaneous && (WizardMode || Verbose)) {
 113     tty->print_cr("vtable #%d at " PTR_FORMAT "[%d] left over: %d",
 114                   vtable_index, p2i(s->entry_point()),
 115                   (int)(s->code_end() - s->entry_point()),
 116                   (int)(s->code_end() - __ pc()));
 117   }
 118   guarantee(__ pc() <= s->code_end(), "overflowed buffer");
 119   // shut the door on sizing bugs
 120   int slop = 2*BytesPerInstWord;  // 32-bit offset is this much larger than a 13-bit one
 121   assert(vtable_index > 10 || __ pc() + slop <= s->code_end(), "room for sethi;add");
 122 
 123   s->set_exception_points(npe_addr, ame_addr);
 124   return s;
 125 }
 126 
 127 
 128 // NOTE:  %%%% if any change is made to this stub make sure that the function
 129 //             pd_code_size_limit is changed to ensure the correct size for VtableStub
 130 VtableStub* VtableStubs::create_itable_stub(int itable_index) {
 131   const int sparc_code_length = VtableStub::pd_code_size_limit(false);
 132   VtableStub* s = new(sparc_code_length) VtableStub(false, itable_index);
 133   // Can be NULL if there is no free space in the code cache.
 134   if (s == NULL) {
 135     return NULL;
 136   }
 137 
 138   ResourceMark rm;
 139   CodeBuffer cb(s->entry_point(), sparc_code_length);
 140   MacroAssembler* masm = new MacroAssembler(&cb);
 141 
 142   Register G3_Klass = G3_scratch;
 143   Register G5_interface = G5;  // Passed in as an argument
 144   Label search;
 145 
 146   // Entry arguments:
 147   //  G5_interface: Interface
 148   //  O0:           Receiver
 149   assert(VtableStub::receiver_location() == O0->as_VMReg(), "receiver expected in O0");
 150 
 151   // get receiver klass (also an implicit null-check)
 152   address npe_addr = __ pc();
 153   __ load_klass(O0, G3_Klass);
 154 
 155   // Push a new window to get some temp registers.  This chops the head of all
 156   // my 64-bit %o registers in the LION build, but this is OK because no longs
 157   // are passed in the %o registers.  Instead, longs are passed in G1 and G4
 158   // and so those registers are not available here.
 159   __ save(SP,-frame::register_save_words*wordSize,SP);
 160 
 161 #ifndef PRODUCT
 162   if (CountCompiledCalls) {
 163     __ inc_counter(SharedRuntime::nof_megamorphic_calls_addr(), L0, L1);
 164   }
 165 #endif /* PRODUCT */
 166 
 167   Label throw_icce;
 168 
 169   Register L5_method = L5;
 170   __ lookup_interface_method(// inputs: rec. class, interface, itable index
 171                              G3_Klass, G5_interface, itable_index,
 172                              // outputs: method, scan temp. reg
 173                              L5_method, L2, L3,
 174                              throw_icce);
 175 
 176 #ifndef PRODUCT
 177   if (DebugVtables) {
 178     Label L01;
 179     __ br_notnull_short(L5_method, Assembler::pt, L01);
 180     __ stop("Method* is null");
 181     __ bind(L01);
 182   }
 183 #endif
 184 
 185   // If the following load is through a NULL pointer, we'll take an OS
 186   // exception that should translate into an AbstractMethodError.  We need the
 187   // window count to be correct at that time.
 188   __ restore(L5_method, 0, G5_method);
 189   // Restore registers *before* the AME point.
 190 
 191   address ame_addr = __ pc();   // if the vtable entry is null, the method is abstract
 192   __ ld_ptr(G5_method, in_bytes(Method::from_compiled_offset()), G3_scratch);
 193 
 194   // G5_method:  Method*
 195   // O0:         Receiver
 196   // G3_scratch: entry point
 197   __ JMP(G3_scratch, 0);
 198   __ delayed()->nop();
 199 
 200   __ bind(throw_icce);
 201   AddressLiteral icce(StubRoutines::throw_IncompatibleClassChangeError_entry());
 202   __ jump_to(icce, G3_scratch);
 203   __ delayed()->restore();
 204 
 205   masm->flush();
 206 
 207   if (PrintMiscellaneous && (WizardMode || Verbose)) {
 208     tty->print_cr("itable #%d at " PTR_FORMAT "[%d] left over: %d",
 209                   itable_index, p2i(s->entry_point()),
 210                   (int)(s->code_end() - s->entry_point()),
 211                   (int)(s->code_end() - __ pc()));
 212   }
 213   guarantee(__ pc() <= s->code_end(), "overflowed buffer");
 214   // shut the door on sizing bugs
 215   int slop = 2*BytesPerInstWord;  // 32-bit offset is this much larger than a 13-bit one
 216   assert(itable_index > 10 || __ pc() + slop <= s->code_end(), "room for sethi;add");
 217 
 218   s->set_exception_points(npe_addr, ame_addr);
 219   return s;
 220 }
 221 
 222 
 223 int VtableStub::pd_code_size_limit(bool is_vtable_stub) {
 224   if (TraceJumps || DebugVtables || CountCompiledCalls || VerifyOops) return 1000;
 225   else {
 226     const int slop = 2*BytesPerInstWord; // sethi;add  (needed for long offsets)
 227     if (is_vtable_stub) {
 228       // ld;ld;ld,jmp,nop
 229       const int basic = 5*BytesPerInstWord +
 230                         // shift;add for load_klass (only shift with zero heap based)
 231                         (UseCompressedClassPointers ?
 232                           MacroAssembler::instr_size_for_decode_klass_not_null() : 0);
 233       return basic + slop;
 234     } else {
 235       const int basic = (28 LP64_ONLY(+ 6)) * BytesPerInstWord +
 236                         // shift;add for load_klass (only shift with zero heap based)
 237                         (UseCompressedClassPointers ?
 238                           MacroAssembler::instr_size_for_decode_klass_not_null() : 0);
 239       return (basic + slop);
 240     }
 241   }
 242 
 243   // In order to tune these parameters, run the JVM with VM options
 244   // +PrintMiscellaneous and +WizardMode to see information about
 245   // actual itable stubs.  Look for lines like this:
 246   //   itable #1 at 0x5551212[116] left over: 8
 247   // Reduce the constants so that the "left over" number is 8
 248   // Do not aim at a left-over number of zero, because a very
 249   // large vtable or itable offset (> 4K) will require an extra
 250   // sethi/or pair of instructions.
 251   //
 252   // The JVM98 app. _202_jess has a megamorphic interface call.
 253   // The itable code looks like this:
 254   // Decoding VtableStub itbl[1]@16
 255   //   ld  [ %o0 + 4 ], %g3
 256   //   save  %sp, -64, %sp
 257   //   ld  [ %g3 + 0xe8 ], %l2
 258   //   sll  %l2, 2, %l2
 259   //   add  %l2, 0x134, %l2
 260   //   and  %l2, -8, %l2        ! NOT_LP64 only
 261   //   add  %g3, %l2, %l2
 262   //   add  %g3, 4, %g3
 263   //   ld  [ %l2 ], %l5
 264   //   brz,pn   %l5, throw_icce
 265   //   cmp  %l5, %g5
 266   //   be  %icc, success
 267   //   add  %l2, 8, %l2
 268   // loop:
 269   //   ld  [ %l2 ], %l5
 270   //   brz,pn   %l5, throw_icce
 271   //   cmp  %l5, %g5
 272   //   bne,pn   %icc, loop
 273   //   add  %l2, 8, %l2
 274   // success:
 275   //   ld  [ %l2 + -4 ], %l2
 276   //   ld  [ %g3 + %l2 ], %l5
 277   //   restore  %l5, 0, %g5
 278   //   ld  [ %g5 + 0x44 ], %g3
 279   //   jmp  %g3
 280   //   nop
 281   // throw_icce:
 282   //   sethi  %hi(throw_ICCE_entry), %g3
 283   //   ! 5 more instructions here, LP64_ONLY
 284   //   jmp  %g3 + %lo(throw_ICCE_entry)
 285   //   restore
 286 }
 287 
 288 
 289 int VtableStub::pd_code_alignment() {
 290   // UltraSPARC cache line size is 8 instructions:
 291   const unsigned int icache_line_size = 32;
 292   return icache_line_size;
 293 }