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/compiledIC.hpp"
  28 #include "code/icBuffer.hpp"
  29 #include "code/nativeInst.hpp"
  30 #include "code/nmethod.hpp"
  31 #include "memory/resourceArea.hpp"
  32 #include "runtime/mutexLocker.hpp"
  33 #include "runtime/safepoint.hpp"
  34 
  35 // ----------------------------------------------------------------------------
  36 #if COMPILER2_OR_JVMCI
  37 #define __ _masm.
  38 // emit call stub, compiled java to interpreter
  39 address CompiledStaticCall::emit_to_interp_stub(CodeBuffer &cbuf, address mark) {
  40   // Stub is fixed up when the corresponding call is converted from calling
  41   // compiled code to calling interpreted code.
  42   // set (empty), R9
  43   // b -1
  44 
  45   if (mark == NULL) {
  46     mark = cbuf.insts_mark();  // get mark within main instrs section
  47   }
  48 
  49   MacroAssembler _masm(&cbuf);
  50 
  51   address base = __ start_a_stub(to_interp_stub_size());
  52   if (base == NULL) {
  53     return NULL;  // CodeBuffer::expand failed
  54   }
  55 
  56   // static stub relocation stores the instruction address of the call
  57   __ relocate(static_stub_Relocation::spec(mark));
  58 
  59   InlinedMetadata object_literal(NULL);
  60   // single instruction, see NativeMovConstReg::next_instruction_address() in
  61   // CompiledStaticCall::set_to_interpreted()
  62   __ ldr_literal(Rmethod, object_literal);
  63 
  64   __ set_inst_mark(); // Who uses this?
  65 
  66   bool near_range = __ cache_fully_reachable();
  67   InlinedAddress dest((address)-1);
  68   address branch_site = __ pc();
  69   if (near_range) {
  70     __ b(branch_site); // special NativeJump -1 destination
  71   } else {
  72     // Can't trash LR, FP, or argument registers
  73     __ indirect_jump(dest, Rtemp);
  74   }
  75   __ bind_literal(object_literal); // includes spec_for_immediate reloc
  76   if (!near_range) {
  77     __ bind_literal(dest); // special NativeJump -1 destination
  78   }
  79 
  80   assert(__ pc() - base <= to_interp_stub_size(), "wrong stub size");
  81 
  82   // Update current stubs pointer and restore code_end.
  83   __ end_a_stub();
  84   return base;
  85 }
  86 #undef __
  87 
  88 // Relocation entries for call stub, compiled java to interpreter.
  89 int CompiledStaticCall::reloc_to_interp_stub() {
  90   return 10;  // 4 in emit_to_interp_stub + 1 in Java_Static_Call
  91 }
  92 #endif // COMPILER2_OR_JVMCI
  93 
  94 // size of C2 call stub, compiled java to interpretor
  95 int CompiledStaticCall::to_interp_stub_size() {
  96   return 8 * NativeInstruction::instruction_size;
  97 }
  98 
  99 void CompiledDirectStaticCall::set_to_interpreted(const methodHandle& callee, address entry) {
 100   address stub = find_stub(/*is_aot*/ false);
 101   guarantee(stub != NULL, "stub not found");
 102 
 103   if (TraceICs) {
 104     ResourceMark rm;
 105     tty->print_cr("CompiledDirectStaticCall@" INTPTR_FORMAT ": set_to_interpreted %s",
 106                   p2i(instruction_address()),
 107                   callee->name_and_sig_as_C_string());
 108   }
 109 
 110   // Creation also verifies the object.
 111   NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
 112   NativeJump*        jump          = nativeJump_at(method_holder->next_instruction_address());
 113 
 114 #ifdef ASSERT
 115   // read the value once
 116   volatile intptr_t data = method_holder->data();
 117   volatile address destination = jump->jump_destination();
 118   assert(data == 0 || data == (intptr_t)callee(),
 119          "a) MT-unsafe modification of inline cache");
 120   assert(destination == (address)-1 || destination == entry,
 121          "b) MT-unsafe modification of inline cache");
 122 #endif
 123 
 124   // Update stub.
 125   method_holder->set_data((intptr_t)callee());
 126   jump->set_jump_destination(entry);
 127 
 128   ICache::invalidate_range(stub, to_interp_stub_size());
 129 
 130   // Update jump to call.
 131   set_destination_mt_safe(stub);
 132 }
 133 
 134 void CompiledDirectStaticCall::set_stub_to_clean(static_stub_Relocation* static_stub) {
 135   assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");
 136   // Reset stub.
 137   address stub = static_stub->addr();
 138   assert(stub != NULL, "stub not found");
 139   // Creation also verifies the object.
 140   NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
 141   NativeJump*        jump          = nativeJump_at(method_holder->next_instruction_address());
 142   method_holder->set_data(0);
 143   jump->set_jump_destination((address)-1);
 144 }
 145 
 146 //-----------------------------------------------------------------------------
 147 // Non-product mode code
 148 #ifndef PRODUCT
 149 
 150 void CompiledDirectStaticCall::verify() {
 151   // Verify call.
 152   _call->verify();
 153   if (os::is_MP()) {
 154     _call->verify_alignment();
 155   }
 156 
 157   // Verify stub.
 158   address stub = find_stub(/*is_aot*/ false);
 159   assert(stub != NULL, "no stub found for static call");
 160   // Creation also verifies the object.
 161   NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
 162   NativeJump*        jump          = nativeJump_at(method_holder->next_instruction_address());
 163 
 164   // Verify state.
 165   assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted(), "sanity check");
 166 }
 167 
 168 #endif // !PRODUCT