Tue, 12 Oct 2010 23:51:20 -0700
6991512: G1 barriers fail with 64bit C1
Summary: Fix compare-and-swap intrinsic problem with G1 post-barriers and issue with branch ranges in G1 stubs on sparc
Reviewed-by: never, kvn
1 /*
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25 #include "incls/_precompiled.incl"
26 #include "incls/_runtime_sparc.cpp.incl"
29 #define __ masm->
31 ExceptionBlob *OptoRuntime::_exception_blob;
33 //------------------------------ generate_exception_blob ---------------------------
34 // creates exception blob at the end
35 // Using exception blob, this code is jumped from a compiled method.
36 // (see emit_exception_handler in sparc.ad file)
37 //
38 // Given an exception pc at a call we call into the runtime for the
39 // handler in this method. This handler might merely restore state
40 // (i.e. callee save registers) unwind the frame and jump to the
41 // exception handler for the nmethod if there is no Java level handler
42 // for the nmethod.
43 //
44 // This code is entered with a jmp.
45 //
46 // Arguments:
47 // O0: exception oop
48 // O1: exception pc
49 //
50 // Results:
51 // O0: exception oop
52 // O1: exception pc in caller or ???
53 // destination: exception handler of caller
54 //
55 // Note: the exception pc MUST be at a call (precise debug information)
56 //
57 void OptoRuntime::generate_exception_blob() {
58 // allocate space for code
59 ResourceMark rm;
60 int pad = VerifyThread ? 256 : 0;// Extra slop space for more verify code
62 // setup code generation tools
63 // Measured 8/7/03 at 256 in 32bit debug build (no VerifyThread)
64 // Measured 8/7/03 at 528 in 32bit debug build (VerifyThread)
65 CodeBuffer buffer("exception_blob", 600+pad, 512);
66 MacroAssembler* masm = new MacroAssembler(&buffer);
68 int framesize_in_bytes = __ total_frame_size_in_bytes(0);
69 int framesize_in_words = framesize_in_bytes / wordSize;
70 int framesize_in_slots = framesize_in_bytes / sizeof(jint);
72 Label L;
74 int start = __ offset();
76 __ verify_thread();
77 __ st_ptr(Oexception, G2_thread, JavaThread::exception_oop_offset());
78 __ st_ptr(Oissuing_pc, G2_thread, JavaThread::exception_pc_offset());
80 // This call does all the hard work. It checks if an exception catch
81 // exists in the method.
82 // If so, it returns the handler address.
83 // If the nmethod has been deoptimized and it had a handler the handler
84 // address is the deopt blob unpack_with_exception entry.
85 //
86 // If no handler exists it prepares for stack-unwinding, restoring the callee-save
87 // registers of the frame being removed.
88 //
89 __ save_frame(0);
91 __ mov(G2_thread, O0);
92 __ set_last_Java_frame(SP, noreg);
93 __ save_thread(L7_thread_cache);
95 // This call can block at exit and nmethod can be deoptimized at that
96 // point. If the nmethod had a catch point we would jump to the
97 // now deoptimized catch point and fall thru the vanilla deopt
98 // path and lose the exception
99 // Sure would be simpler if this call didn't block!
100 __ call(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C), relocInfo::runtime_call_type);
101 __ delayed()->mov(L7_thread_cache, O0);
103 // Set an oopmap for the call site. This oopmap will only be used if we
104 // are unwinding the stack. Hence, all locations will be dead.
105 // Callee-saved registers will be the same as the frame above (i.e.,
106 // handle_exception_stub), since they were restored when we got the
107 // exception.
109 OopMapSet *oop_maps = new OopMapSet();
110 oop_maps->add_gc_map( __ offset()-start, new OopMap(framesize_in_slots, 0));
112 __ bind(L);
113 __ restore_thread(L7_thread_cache);
114 __ reset_last_Java_frame();
116 __ mov(O0, G3_scratch); // Move handler address to temp
117 __ restore();
119 // Restore SP from L7 if the exception PC is a MethodHandle call site.
120 __ lduw(Address(G2_thread, JavaThread::is_method_handle_return_offset()), O7);
121 __ tst(O7);
122 __ movcc(Assembler::notZero, false, Assembler::icc, L7_mh_SP_save, SP);
124 // G3_scratch contains handler address
125 // Since this may be the deopt blob we must set O7 to look like we returned
126 // from the original pc that threw the exception
128 __ ld_ptr(G2_thread, JavaThread::exception_pc_offset(), O7);
129 __ sub(O7, frame::pc_return_offset, O7);
132 assert(Assembler::is_simm13(in_bytes(JavaThread::exception_oop_offset())), "exception offset overflows simm13, following ld instruction cannot be in delay slot");
133 __ ld_ptr(G2_thread, JavaThread::exception_oop_offset(), Oexception); // O0
134 #ifdef ASSERT
135 __ st_ptr(G0, G2_thread, JavaThread::exception_handler_pc_offset());
136 __ st_ptr(G0, G2_thread, JavaThread::exception_pc_offset());
137 #endif
138 __ JMP(G3_scratch, 0);
139 // Clear the exception oop so GC no longer processes it as a root.
140 __ delayed()->st_ptr(G0, G2_thread, JavaThread::exception_oop_offset());
142 // -------------
143 // make sure all code is generated
144 masm->flush();
146 _exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize_in_words);
147 }