1.1 --- a/src/cpu/x86/vm/templateInterpreter_x86_32.cpp Wed Apr 06 16:02:53 2011 -0700
1.2 +++ b/src/cpu/x86/vm/templateInterpreter_x86_32.cpp Fri Apr 08 14:19:50 2011 -0700
1.3 @@ -776,6 +776,98 @@
1.4
1.5 }
1.6
1.7 +// Method entry for java.lang.ref.Reference.get.
1.8 +address InterpreterGenerator::generate_Reference_get_entry(void) {
1.9 +#ifndef SERIALGC
1.10 + // Code: _aload_0, _getfield, _areturn
1.11 + // parameter size = 1
1.12 + //
1.13 + // The code that gets generated by this routine is split into 2 parts:
1.14 + // 1. The "intrinsified" code for G1 (or any SATB based GC),
1.15 + // 2. The slow path - which is an expansion of the regular method entry.
1.16 + //
1.17 + // Notes:-
1.18 + // * In the G1 code we do not check whether we need to block for
1.19 + // a safepoint. If G1 is enabled then we must execute the specialized
1.20 + // code for Reference.get (except when the Reference object is null)
1.21 + // so that we can log the value in the referent field with an SATB
1.22 + // update buffer.
1.23 + // If the code for the getfield template is modified so that the
1.24 + // G1 pre-barrier code is executed when the current method is
1.25 + // Reference.get() then going through the normal method entry
1.26 + // will be fine.
1.27 + // * The G1 code below can, however, check the receiver object (the instance
1.28 + // of java.lang.Reference) and jump to the slow path if null. If the
1.29 + // Reference object is null then we obviously cannot fetch the referent
1.30 + // and so we don't need to call the G1 pre-barrier. Thus we can use the
1.31 + // regular method entry code to generate the NPE.
1.32 + //
1.33 + // This code is based on generate_accessor_enty.
1.34 +
1.35 + // rbx,: methodOop
1.36 + // rcx: receiver (preserve for slow entry into asm interpreter)
1.37 +
1.38 + // rsi: senderSP must preserved for slow path, set SP to it on fast path
1.39 +
1.40 + address entry = __ pc();
1.41 +
1.42 + const int referent_offset = java_lang_ref_Reference::referent_offset;
1.43 + guarantee(referent_offset > 0, "referent offset not initialized");
1.44 +
1.45 + if (UseG1GC) {
1.46 + Label slow_path;
1.47 +
1.48 + // Check if local 0 != NULL
1.49 + // If the receiver is null then it is OK to jump to the slow path.
1.50 + __ movptr(rax, Address(rsp, wordSize));
1.51 + __ testptr(rax, rax);
1.52 + __ jcc(Assembler::zero, slow_path);
1.53 +
1.54 + // rax: local 0 (must be preserved across the G1 barrier call)
1.55 + //
1.56 + // rbx: method (at this point it's scratch)
1.57 + // rcx: receiver (at this point it's scratch)
1.58 + // rdx: scratch
1.59 + // rdi: scratch
1.60 + //
1.61 + // rsi: sender sp
1.62 +
1.63 + // Preserve the sender sp in case the pre-barrier
1.64 + // calls the runtime
1.65 + __ push(rsi);
1.66 +
1.67 + // Load the value of the referent field.
1.68 + const Address field_address(rax, referent_offset);
1.69 + __ movptr(rax, field_address);
1.70 +
1.71 + // Generate the G1 pre-barrier code to log the value of
1.72 + // the referent field in an SATB buffer.
1.73 + __ get_thread(rcx);
1.74 + __ g1_write_barrier_pre(noreg /* obj */,
1.75 + rax /* pre_val */,
1.76 + rcx /* thread */,
1.77 + rbx /* tmp */,
1.78 + true /* tosca_save */,
1.79 + true /* expand_call */);
1.80 +
1.81 + // _areturn
1.82 + __ pop(rsi); // get sender sp
1.83 + __ pop(rdi); // get return address
1.84 + __ mov(rsp, rsi); // set sp to sender sp
1.85 + __ jmp(rdi);
1.86 +
1.87 + __ bind(slow_path);
1.88 + (void) generate_normal_entry(false);
1.89 +
1.90 + return entry;
1.91 + }
1.92 +#endif // SERIALGC
1.93 +
1.94 + // If G1 is not enabled then attempt to go through the accessor entry point
1.95 + // Reference.get is an accessor
1.96 + return generate_accessor_entry();
1.97 +}
1.98 +
1.99 //
1.100 // Interpreter stub for calling a native method. (asm interpreter)
1.101 // This sets up a somewhat different looking stack for calling the native method
1.102 @@ -1444,6 +1536,8 @@
1.103 case Interpreter::java_lang_math_log : // fall thru
1.104 case Interpreter::java_lang_math_log10 : // fall thru
1.105 case Interpreter::java_lang_math_sqrt : entry_point = ((InterpreterGenerator*)this)->generate_math_entry(kind); break;
1.106 + case Interpreter::java_lang_ref_reference_get
1.107 + : entry_point = ((InterpreterGenerator*)this)->generate_Reference_get_entry(); break;
1.108 default : ShouldNotReachHere(); break;
1.109 }
1.110
