Mercurial > hg > aarch64-jdk8u51-b16-hotspot
changeset 7830:c47a4731e5e0
Add java.lang.ref.Reference.get intrinsic to template interpreter
author | enevill |
---|---|
date | Tue, 06 Jan 2015 15:57:27 +0000 |
parents | 57843614fd14 |
children | 06c52e8fd6d3 |
files | src/cpu/aarch64/vm/templateInterpreter_aarch64.cpp |
diffstat | 1 files changed, 72 insertions(+), 1 deletions(-) [+] |
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--- a/src/cpu/aarch64/vm/templateInterpreter_aarch64.cpp Fri Dec 19 06:31:51 2014 -0500 +++ b/src/cpu/aarch64/vm/templateInterpreter_aarch64.cpp Tue Jan 06 15:57:27 2015 +0000 @@ -670,7 +670,78 @@ // Method entry for java.lang.ref.Reference.get. address InterpreterGenerator::generate_Reference_get_entry(void) { - return NULL; +#if INCLUDE_ALL_GCS + // Code: _aload_0, _getfield, _areturn + // parameter size = 1 + // + // The code that gets generated by this routine is split into 2 parts: + // 1. The "intrinsified" code for G1 (or any SATB based GC), + // 2. The slow path - which is an expansion of the regular method entry. + // + // Notes:- + // * In the G1 code we do not check whether we need to block for + // a safepoint. If G1 is enabled then we must execute the specialized + // code for Reference.get (except when the Reference object is null) + // so that we can log the value in the referent field with an SATB + // update buffer. + // If the code for the getfield template is modified so that the + // G1 pre-barrier code is executed when the current method is + // Reference.get() then going through the normal method entry + // will be fine. + // * The G1 code can, however, check the receiver object (the instance + // of java.lang.Reference) and jump to the slow path if null. If the + // Reference object is null then we obviously cannot fetch the referent + // and so we don't need to call the G1 pre-barrier. Thus we can use the + // regular method entry code to generate the NPE. + // + // This code is based on generate_accessor_enty. + // + // rmethod: Method* + // r13: senderSP must preserve for slow path, set SP to it on fast path + + address entry = __ pc(); + + const int referent_offset = java_lang_ref_Reference::referent_offset; + guarantee(referent_offset > 0, "referent offset not initialized"); + + if (UseG1GC) { + Label slow_path; + const Register local_0 = c_rarg0; + // Check if local 0 != NULL + // If the receiver is null then it is OK to jump to the slow path. + __ ldr(local_0, Address(esp, 0)); + __ cbz(local_0, slow_path); + + + // Load the value of the referent field. + const Address field_address(local_0, referent_offset); + __ load_heap_oop(local_0, field_address); + + // Generate the G1 pre-barrier code to log the value of + // the referent field in an SATB buffer. + __ enter(); // g1_write may call runtime + __ g1_write_barrier_pre(noreg /* obj */, + local_0 /* pre_val */, + rthread /* thread */, + rscratch2 /* tmp */, + true /* tosca_live */, + true /* expand_call */); + __ leave(); + // areturn + __ andr(sp, r13, -16); // done with stack + __ ret(lr); + + // generate a vanilla interpreter entry as the slow path + __ bind(slow_path); + (void) generate_normal_entry(false); + + return entry; + } +#endif // INCLUDE_ALL_GCS + + // If G1 is not enabled then attempt to go through the accessor entry point + // Reference.get is an accessor + return generate_accessor_entry(); } /**