Mon, 26 Sep 2011 10:24:05 -0700
7081933: Use zeroing elimination optimization for large array
Summary: Don't zero new typeArray during runtime call if the allocation is followed by arraycopy into it.
Reviewed-by: twisti
1 /*
2 * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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.
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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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
25 #include "precompiled.hpp"
26 #ifdef COMPILER2
27 #include "asm/assembler.hpp"
28 #include "assembler_sparc.inline.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "code/vmreg.hpp"
31 #include "interpreter/interpreter.hpp"
32 #include "nativeInst_sparc.hpp"
33 #include "opto/runtime.hpp"
34 #include "runtime/interfaceSupport.hpp"
35 #include "runtime/sharedRuntime.hpp"
36 #include "runtime/stubRoutines.hpp"
37 #include "runtime/vframeArray.hpp"
38 #include "utilities/globalDefinitions.hpp"
39 #include "vmreg_sparc.inline.hpp"
40 #endif
43 #define __ masm->
45 //------------------------------ generate_exception_blob ---------------------------
46 // creates exception blob at the end
47 // Using exception blob, this code is jumped from a compiled method.
48 // (see emit_exception_handler in sparc.ad file)
49 //
50 // Given an exception pc at a call we call into the runtime for the
51 // handler in this method. This handler might merely restore state
52 // (i.e. callee save registers) unwind the frame and jump to the
53 // exception handler for the nmethod if there is no Java level handler
54 // for the nmethod.
55 //
56 // This code is entered with a jmp.
57 //
58 // Arguments:
59 // O0: exception oop
60 // O1: exception pc
61 //
62 // Results:
63 // O0: exception oop
64 // O1: exception pc in caller or ???
65 // destination: exception handler of caller
66 //
67 // Note: the exception pc MUST be at a call (precise debug information)
68 //
69 void OptoRuntime::generate_exception_blob() {
70 // allocate space for code
71 ResourceMark rm;
72 int pad = VerifyThread ? 256 : 0;// Extra slop space for more verify code
74 // setup code generation tools
75 // Measured 8/7/03 at 256 in 32bit debug build (no VerifyThread)
76 // Measured 8/7/03 at 528 in 32bit debug build (VerifyThread)
77 CodeBuffer buffer("exception_blob", 600+pad, 512);
78 MacroAssembler* masm = new MacroAssembler(&buffer);
80 int framesize_in_bytes = __ total_frame_size_in_bytes(0);
81 int framesize_in_words = framesize_in_bytes / wordSize;
82 int framesize_in_slots = framesize_in_bytes / sizeof(jint);
84 Label L;
86 int start = __ offset();
88 __ verify_thread();
89 __ st_ptr(Oexception, G2_thread, JavaThread::exception_oop_offset());
90 __ st_ptr(Oissuing_pc, G2_thread, JavaThread::exception_pc_offset());
92 // This call does all the hard work. It checks if an exception catch
93 // exists in the method.
94 // If so, it returns the handler address.
95 // If the nmethod has been deoptimized and it had a handler the handler
96 // address is the deopt blob unpack_with_exception entry.
97 //
98 // If no handler exists it prepares for stack-unwinding, restoring the callee-save
99 // registers of the frame being removed.
100 //
101 __ save_frame(0);
103 __ mov(G2_thread, O0);
104 __ set_last_Java_frame(SP, noreg);
105 __ save_thread(L7_thread_cache);
107 // This call can block at exit and nmethod can be deoptimized at that
108 // point. If the nmethod had a catch point we would jump to the
109 // now deoptimized catch point and fall thru the vanilla deopt
110 // path and lose the exception
111 // Sure would be simpler if this call didn't block!
112 __ call(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C), relocInfo::runtime_call_type);
113 __ delayed()->mov(L7_thread_cache, O0);
115 // Set an oopmap for the call site. This oopmap will only be used if we
116 // are unwinding the stack. Hence, all locations will be dead.
117 // Callee-saved registers will be the same as the frame above (i.e.,
118 // handle_exception_stub), since they were restored when we got the
119 // exception.
121 OopMapSet *oop_maps = new OopMapSet();
122 oop_maps->add_gc_map( __ offset()-start, new OopMap(framesize_in_slots, 0));
124 __ bind(L);
125 __ restore_thread(L7_thread_cache);
126 __ reset_last_Java_frame();
128 __ mov(O0, G3_scratch); // Move handler address to temp
129 __ restore();
131 // Restore SP from L7 if the exception PC is a MethodHandle call site.
132 __ lduw(Address(G2_thread, JavaThread::is_method_handle_return_offset()), O7);
133 __ tst(O7);
134 __ movcc(Assembler::notZero, false, Assembler::icc, L7_mh_SP_save, SP);
136 // G3_scratch contains handler address
137 // Since this may be the deopt blob we must set O7 to look like we returned
138 // from the original pc that threw the exception
140 __ ld_ptr(G2_thread, JavaThread::exception_pc_offset(), O7);
141 __ sub(O7, frame::pc_return_offset, O7);
144 assert(Assembler::is_simm13(in_bytes(JavaThread::exception_oop_offset())), "exception offset overflows simm13, following ld instruction cannot be in delay slot");
145 __ ld_ptr(G2_thread, JavaThread::exception_oop_offset(), Oexception); // O0
146 #ifdef ASSERT
147 __ st_ptr(G0, G2_thread, JavaThread::exception_handler_pc_offset());
148 __ st_ptr(G0, G2_thread, JavaThread::exception_pc_offset());
149 #endif
150 __ JMP(G3_scratch, 0);
151 // Clear the exception oop so GC no longer processes it as a root.
152 __ delayed()->st_ptr(G0, G2_thread, JavaThread::exception_oop_offset());
154 // -------------
155 // make sure all code is generated
156 masm->flush();
158 _exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize_in_words);
159 }