Mercurial > hg > truffle
comparison src/share/vm/asm/assembler.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | 1fdb98a17101 |
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1 /* | |
2 * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved. | |
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
4 * | |
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. | |
8 * | |
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. | |
18 * | |
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 #include "incls/_precompiled.incl" | |
26 #include "incls/_assembler.cpp.incl" | |
27 | |
28 | |
29 // Implementation of AbstractAssembler | |
30 // | |
31 // The AbstractAssembler is generating code into a CodeBuffer. To make code generation faster, | |
32 // the assembler keeps a copy of the code buffers boundaries & modifies them when | |
33 // emitting bytes rather than using the code buffers accessor functions all the time. | |
34 // The code buffer is updated via set_code_end(...) after emiting a whole instruction. | |
35 | |
36 AbstractAssembler::AbstractAssembler(CodeBuffer* code) { | |
37 if (code == NULL) return; | |
38 CodeSection* cs = code->insts(); | |
39 cs->clear_mark(); // new assembler kills old mark | |
40 _code_section = cs; | |
41 _code_begin = cs->start(); | |
42 _code_limit = cs->limit(); | |
43 _code_pos = cs->end(); | |
44 _oop_recorder= code->oop_recorder(); | |
45 if (_code_begin == NULL) { | |
46 vm_exit_out_of_memory1(0, "CodeCache: no room for %s", code->name()); | |
47 } | |
48 } | |
49 | |
50 void AbstractAssembler::set_code_section(CodeSection* cs) { | |
51 assert(cs->outer() == code_section()->outer(), "sanity"); | |
52 assert(cs->is_allocated(), "need to pre-allocate this section"); | |
53 cs->clear_mark(); // new assembly into this section kills old mark | |
54 _code_section = cs; | |
55 _code_begin = cs->start(); | |
56 _code_limit = cs->limit(); | |
57 _code_pos = cs->end(); | |
58 } | |
59 | |
60 // Inform CodeBuffer that incoming code and relocation will be for stubs | |
61 address AbstractAssembler::start_a_stub(int required_space) { | |
62 CodeBuffer* cb = code(); | |
63 CodeSection* cs = cb->stubs(); | |
64 assert(_code_section == cb->insts(), "not in insts?"); | |
65 sync(); | |
66 if (cs->maybe_expand_to_ensure_remaining(required_space) | |
67 && cb->blob() == NULL) { | |
68 return NULL; | |
69 } | |
70 set_code_section(cs); | |
71 return pc(); | |
72 } | |
73 | |
74 // Inform CodeBuffer that incoming code and relocation will be code | |
75 // Should not be called if start_a_stub() returned NULL | |
76 void AbstractAssembler::end_a_stub() { | |
77 assert(_code_section == code()->stubs(), "not in stubs?"); | |
78 sync(); | |
79 set_code_section(code()->insts()); | |
80 } | |
81 | |
82 // Inform CodeBuffer that incoming code and relocation will be for stubs | |
83 address AbstractAssembler::start_a_const(int required_space, int required_align) { | |
84 CodeBuffer* cb = code(); | |
85 CodeSection* cs = cb->consts(); | |
86 assert(_code_section == cb->insts(), "not in insts?"); | |
87 sync(); | |
88 address end = cs->end(); | |
89 int pad = -(intptr_t)end & (required_align-1); | |
90 if (cs->maybe_expand_to_ensure_remaining(pad + required_space)) { | |
91 if (cb->blob() == NULL) return NULL; | |
92 end = cs->end(); // refresh pointer | |
93 } | |
94 if (pad > 0) { | |
95 while (--pad >= 0) { *end++ = 0; } | |
96 cs->set_end(end); | |
97 } | |
98 set_code_section(cs); | |
99 return end; | |
100 } | |
101 | |
102 // Inform CodeBuffer that incoming code and relocation will be code | |
103 // Should not be called if start_a_const() returned NULL | |
104 void AbstractAssembler::end_a_const() { | |
105 assert(_code_section == code()->consts(), "not in consts?"); | |
106 sync(); | |
107 set_code_section(code()->insts()); | |
108 } | |
109 | |
110 | |
111 void AbstractAssembler::flush() { | |
112 sync(); | |
113 ICache::invalidate_range(addr_at(0), offset()); | |
114 } | |
115 | |
116 | |
117 void AbstractAssembler::a_byte(int x) { | |
118 emit_byte(x); | |
119 } | |
120 | |
121 | |
122 void AbstractAssembler::a_long(jint x) { | |
123 emit_long(x); | |
124 } | |
125 | |
126 // Labels refer to positions in the (to be) generated code. There are bound | |
127 // and unbound | |
128 // | |
129 // Bound labels refer to known positions in the already generated code. | |
130 // offset() is the position the label refers to. | |
131 // | |
132 // Unbound labels refer to unknown positions in the code to be generated; it | |
133 // may contain a list of unresolved displacements that refer to it | |
134 #ifndef PRODUCT | |
135 void AbstractAssembler::print(Label& L) { | |
136 if (L.is_bound()) { | |
137 tty->print_cr("bound label to %d|%d", L.loc_pos(), L.loc_sect()); | |
138 } else if (L.is_unbound()) { | |
139 L.print_instructions((MacroAssembler*)this); | |
140 } else { | |
141 tty->print_cr("label in inconsistent state (loc = %d)", L.loc()); | |
142 } | |
143 } | |
144 #endif // PRODUCT | |
145 | |
146 | |
147 void AbstractAssembler::bind(Label& L) { | |
148 if (L.is_bound()) { | |
149 // Assembler can bind a label more than once to the same place. | |
150 guarantee(L.loc() == locator(), "attempt to redefine label"); | |
151 return; | |
152 } | |
153 L.bind_loc(locator()); | |
154 L.patch_instructions((MacroAssembler*)this); | |
155 } | |
156 | |
157 void AbstractAssembler::generate_stack_overflow_check( int frame_size_in_bytes) { | |
158 if (UseStackBanging) { | |
159 // Each code entry causes one stack bang n pages down the stack where n | |
160 // is configurable by StackBangPages. The setting depends on the maximum | |
161 // depth of VM call stack or native before going back into java code, | |
162 // since only java code can raise a stack overflow exception using the | |
163 // stack banging mechanism. The VM and native code does not detect stack | |
164 // overflow. | |
165 // The code in JavaCalls::call() checks that there is at least n pages | |
166 // available, so all entry code needs to do is bang once for the end of | |
167 // this shadow zone. | |
168 // The entry code may need to bang additional pages if the framesize | |
169 // is greater than a page. | |
170 | |
171 const int page_size = os::vm_page_size(); | |
172 int bang_end = StackShadowPages*page_size; | |
173 | |
174 // This is how far the previous frame's stack banging extended. | |
175 const int bang_end_safe = bang_end; | |
176 | |
177 if (frame_size_in_bytes > page_size) { | |
178 bang_end += frame_size_in_bytes; | |
179 } | |
180 | |
181 int bang_offset = bang_end_safe; | |
182 while (bang_offset <= bang_end) { | |
183 // Need at least one stack bang at end of shadow zone. | |
184 bang_stack_with_offset(bang_offset); | |
185 bang_offset += page_size; | |
186 } | |
187 } // end (UseStackBanging) | |
188 } | |
189 | |
190 void Label::add_patch_at(CodeBuffer* cb, int branch_loc) { | |
191 assert(_loc == -1, "Label is unbound"); | |
192 if (_patch_index < PatchCacheSize) { | |
193 _patches[_patch_index] = branch_loc; | |
194 } else { | |
195 if (_patch_overflow == NULL) { | |
196 _patch_overflow = cb->create_patch_overflow(); | |
197 } | |
198 _patch_overflow->push(branch_loc); | |
199 } | |
200 ++_patch_index; | |
201 } | |
202 | |
203 void Label::patch_instructions(MacroAssembler* masm) { | |
204 assert(is_bound(), "Label is bound"); | |
205 CodeBuffer* cb = masm->code(); | |
206 int target_sect = CodeBuffer::locator_sect(loc()); | |
207 address target = cb->locator_address(loc()); | |
208 while (_patch_index > 0) { | |
209 --_patch_index; | |
210 int branch_loc; | |
211 if (_patch_index >= PatchCacheSize) { | |
212 branch_loc = _patch_overflow->pop(); | |
213 } else { | |
214 branch_loc = _patches[_patch_index]; | |
215 } | |
216 int branch_sect = CodeBuffer::locator_sect(branch_loc); | |
217 address branch = cb->locator_address(branch_loc); | |
218 if (branch_sect == CodeBuffer::SECT_CONSTS) { | |
219 // The thing to patch is a constant word. | |
220 *(address*)branch = target; | |
221 continue; | |
222 } | |
223 | |
224 #ifdef ASSERT | |
225 // Cross-section branches only work if the | |
226 // intermediate section boundaries are frozen. | |
227 if (target_sect != branch_sect) { | |
228 for (int n = MIN2(target_sect, branch_sect), | |
229 nlimit = (target_sect + branch_sect) - n; | |
230 n < nlimit; n++) { | |
231 CodeSection* cs = cb->code_section(n); | |
232 assert(cs->is_frozen(), "cross-section branch needs stable offsets"); | |
233 } | |
234 } | |
235 #endif //ASSERT | |
236 | |
237 // Push the target offset into the branch instruction. | |
238 masm->pd_patch_instruction(branch, target); | |
239 } | |
240 } | |
241 | |
242 | |
243 void AbstractAssembler::block_comment(const char* comment) { | |
244 if (sect() == CodeBuffer::SECT_INSTS) { | |
245 code_section()->outer()->block_comment(offset(), comment); | |
246 } | |
247 } | |
248 | |
249 | |
250 #ifndef PRODUCT | |
251 void Label::print_instructions(MacroAssembler* masm) const { | |
252 CodeBuffer* cb = masm->code(); | |
253 for (int i = 0; i < _patch_index; ++i) { | |
254 int branch_loc; | |
255 if (i >= PatchCacheSize) { | |
256 branch_loc = _patch_overflow->at(i - PatchCacheSize); | |
257 } else { | |
258 branch_loc = _patches[i]; | |
259 } | |
260 int branch_pos = CodeBuffer::locator_pos(branch_loc); | |
261 int branch_sect = CodeBuffer::locator_sect(branch_loc); | |
262 address branch = cb->locator_address(branch_loc); | |
263 tty->print_cr("unbound label"); | |
264 tty->print("@ %d|%d ", branch_pos, branch_sect); | |
265 if (branch_sect == CodeBuffer::SECT_CONSTS) { | |
266 tty->print_cr(PTR_FORMAT, *(address*)branch); | |
267 continue; | |
268 } | |
269 masm->pd_print_patched_instruction(branch); | |
270 tty->cr(); | |
271 } | |
272 } | |
273 #endif // ndef PRODUCT |