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.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "code/icBuffer.hpp"
  29 #include "gc/shared/collectedHeap.inline.hpp"
  30 #include "interpreter/bytecodes.hpp"
  31 #include "memory/resourceArea.hpp"
  32 #include "nativeInst_x86.hpp"
  33 #include "oops/oop.inline.hpp"
  34 
  35 int InlineCacheBuffer::ic_stub_code_size() {
  36   return NativeMovConstReg::instruction_size +
  37          NativeJump::instruction_size +
  38          1;
  39   // so that code_end can be set in CodeBuffer
  40   // 64bit 16 = 5 + 10 bytes + 1 byte
  41   // 32bit 11 = 10 bytes + 1 byte






  42 }
  43 
  44 
  45 
  46 void InlineCacheBuffer::assemble_ic_buffer_code(address code_begin, void* cached_value, address entry_point) {
  47   ResourceMark rm;
  48   CodeBuffer      code(code_begin, ic_stub_code_size());
  49   MacroAssembler* masm            = new MacroAssembler(&code);
  50   // note: even though the code contains an embedded value, we do not need reloc info
  51   // because
  52   // (1) the value is old (i.e., doesn't matter for scavenges)
  53   // (2) these ICStubs are removed *before* a GC happens, so the roots disappear
  54   // assert(cached_value == NULL || cached_oop->is_perm(), "must be perm oop");
  55   masm->lea(rax, AddressLiteral((address) cached_value, relocInfo::metadata_type));
  56   masm->jump(ExternalAddress(entry_point));
  57 }
  58 
  59 
  60 address InlineCacheBuffer::ic_buffer_entry_point(address code_begin) {
  61   NativeMovConstReg* move = nativeMovConstReg_at(code_begin);   // creation also verifies the object
  62   NativeJump*        jump = nativeJump_at(move->next_instruction_address());



  63   return jump->jump_destination();





  64 }
  65 
  66 
  67 void* InlineCacheBuffer::ic_buffer_cached_value(address code_begin) {
  68   // creation also verifies the object
  69   NativeMovConstReg* move = nativeMovConstReg_at(code_begin);
  70   // Verifies the jump
  71   NativeJump*        jump = nativeJump_at(move->next_instruction_address());







  72   void* o = (void*)move->data();
  73   return o;
  74 }

  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.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "code/icBuffer.hpp"
  29 #include "gc/shared/collectedHeap.inline.hpp"
  30 #include "interpreter/bytecodes.hpp"
  31 #include "memory/resourceArea.hpp"
  32 #include "nativeInst_x86.hpp"
  33 #include "oops/oop.inline.hpp"
  34 
  35 int InlineCacheBuffer::ic_stub_code_size() {
  36   // Worst case, if destination is not a near call:
  37   // lea rax, lit1
  38   // lea scratch, lit2
  39   // jmp scratch
  40 
  41   // Best case
  42   // lea rax, lit1
  43   // jmp lit2
  44 
  45   int best = NativeMovConstReg::instruction_size + NativeJump::instruction_size;
  46   int worst = 2 * NativeMovConstReg::instruction_size + 3;
  47   return MAX2(best, worst);
  48 }
  49 
  50 
  51 
  52 void InlineCacheBuffer::assemble_ic_buffer_code(address code_begin, void* cached_value, address entry_point) {
  53   ResourceMark rm;
  54   CodeBuffer      code(code_begin, ic_stub_code_size());
  55   MacroAssembler* masm            = new MacroAssembler(&code);
  56   // note: even though the code contains an embedded value, we do not need reloc info
  57   // because
  58   // (1) the value is old (i.e., doesn't matter for scavenges)
  59   // (2) these ICStubs are removed *before* a GC happens, so the roots disappear
  60   // assert(cached_value == NULL || cached_oop->is_perm(), "must be perm oop");
  61   masm->lea(rax, AddressLiteral((address) cached_value, relocInfo::metadata_type));
  62   masm->jump(ExternalAddress(entry_point));
  63 }
  64 
  65 
  66 address InlineCacheBuffer::ic_buffer_entry_point(address code_begin) {
  67   NativeMovConstReg* move = nativeMovConstReg_at(code_begin);   // creation also verifies the object
  68   address jmp = move->next_instruction_address();
  69   NativeInstruction* ni = nativeInstruction_at(jmp);
  70   if (ni->is_jump()) {
  71     NativeJump*        jump = nativeJump_at(jmp);
  72     return jump->jump_destination();
  73   } else {
  74     assert(ni->is_far_jump(), "unexpected instruction");
  75     NativeFarJump*     jump = nativeFarJump_at(jmp);
  76     return jump->jump_destination();
  77   }
  78 }
  79 
  80 
  81 void* InlineCacheBuffer::ic_buffer_cached_value(address code_begin) {
  82   // creation also verifies the object
  83   NativeMovConstReg* move = nativeMovConstReg_at(code_begin);
  84   // Verifies the jump
  85   address jmp = move->next_instruction_address();
  86   NativeInstruction* ni = nativeInstruction_at(jmp);
  87   if (ni->is_jump()) {
  88     NativeJump*        jump = nativeJump_at(jmp);
  89   } else {
  90     assert(ni->is_far_jump(), "unexpected instruction");
  91     NativeFarJump*     jump = nativeFarJump_at(jmp);
  92   }
  93   void* o = (void*)move->data();
  94   return o;
  95 }