Mercurial > hg > truffle
annotate src/cpu/x86/vm/c1_LinearScan_x86.cpp @ 2007:5ddfcf4b079e
7003554: (tiered) assert(is_null_object() || handle() != NULL) failed: cannot embed null pointer
Summary: C1 with profiling doesn't check whether the MDO has been really allocated, which can silently fail if the perm gen is full. The solution is to check if the allocation failed and bailout out of inlining or compilation.
Reviewed-by: kvn, never
author | iveresov |
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date | Thu, 02 Dec 2010 17:21:12 -0800 |
parents | f95d63e2154a |
children | 6759698e3140 |
rev | line source |
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0 | 1 /* |
1972 | 2 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. |
0 | 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 * | |
1552
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
c18cbe5936b8
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #include "precompiled.hpp" |
26 #include "c1/c1_Instruction.hpp" | |
27 #include "c1/c1_LinearScan.hpp" | |
28 #include "utilities/bitMap.inline.hpp" | |
0 | 29 |
30 | |
31 //---------------------------------------------------------------------- | |
32 // Allocation of FPU stack slots (Intel x86 only) | |
33 //---------------------------------------------------------------------- | |
34 | |
35 void LinearScan::allocate_fpu_stack() { | |
36 // First compute which FPU registers are live at the start of each basic block | |
37 // (To minimize the amount of work we have to do if we have to merge FPU stacks) | |
38 if (ComputeExactFPURegisterUsage) { | |
39 Interval* intervals_in_register, *intervals_in_memory; | |
40 create_unhandled_lists(&intervals_in_register, &intervals_in_memory, is_in_fpu_register, NULL); | |
41 | |
42 // ignore memory intervals by overwriting intervals_in_memory | |
43 // the dummy interval is needed to enforce the walker to walk until the given id: | |
44 // without it, the walker stops when the unhandled-list is empty -> live information | |
45 // beyond this point would be incorrect. | |
46 Interval* dummy_interval = new Interval(any_reg); | |
47 dummy_interval->add_range(max_jint - 2, max_jint - 1); | |
48 dummy_interval->set_next(Interval::end()); | |
49 intervals_in_memory = dummy_interval; | |
50 | |
51 IntervalWalker iw(this, intervals_in_register, intervals_in_memory); | |
52 | |
53 const int num_blocks = block_count(); | |
54 for (int i = 0; i < num_blocks; i++) { | |
55 BlockBegin* b = block_at(i); | |
56 | |
57 // register usage is only needed for merging stacks -> compute only | |
58 // when more than one predecessor. | |
59 // the block must not have any spill moves at the beginning (checked by assertions) | |
60 // spill moves would use intervals that are marked as handled and so the usage bit | |
61 // would been set incorrectly | |
62 | |
63 // NOTE: the check for number_of_preds > 1 is necessary. A block with only one | |
64 // predecessor may have spill moves at the begin of the block. | |
65 // If an interval ends at the current instruction id, it is not possible | |
66 // to decide if the register is live or not at the block begin -> the | |
67 // register information would be incorrect. | |
68 if (b->number_of_preds() > 1) { | |
69 int id = b->first_lir_instruction_id(); | |
70 BitMap regs(FrameMap::nof_fpu_regs); | |
71 regs.clear(); | |
72 | |
73 iw.walk_to(id); // walk after the first instruction (always a label) of the block | |
74 assert(iw.current_position() == id, "did not walk completely to id"); | |
75 | |
76 // Only consider FPU values in registers | |
77 Interval* interval = iw.active_first(fixedKind); | |
78 while (interval != Interval::end()) { | |
79 int reg = interval->assigned_reg(); | |
80 assert(reg >= pd_first_fpu_reg && reg <= pd_last_fpu_reg, "no fpu register"); | |
81 assert(interval->assigned_regHi() == -1, "must not have hi register (doubles stored in one register)"); | |
82 assert(interval->from() <= id && id < interval->to(), "interval out of range"); | |
83 | |
84 #ifndef PRODUCT | |
85 if (TraceFPURegisterUsage) { | |
86 tty->print("fpu reg %d is live because of ", reg - pd_first_fpu_reg); interval->print(); | |
87 } | |
88 #endif | |
89 | |
90 regs.set_bit(reg - pd_first_fpu_reg); | |
91 interval = interval->next(); | |
92 } | |
93 | |
94 b->set_fpu_register_usage(regs); | |
95 | |
96 #ifndef PRODUCT | |
97 if (TraceFPURegisterUsage) { | |
98 tty->print("FPU regs for block %d, LIR instr %d): ", b->block_id(), id); regs.print_on(tty); tty->print_cr(""); | |
99 } | |
100 #endif | |
101 } | |
102 } | |
103 } | |
104 | |
105 FpuStackAllocator alloc(ir()->compilation(), this); | |
106 _fpu_stack_allocator = &alloc; | |
107 alloc.allocate(); | |
108 _fpu_stack_allocator = NULL; | |
109 } | |
110 | |
111 | |
112 FpuStackAllocator::FpuStackAllocator(Compilation* compilation, LinearScan* allocator) | |
113 : _compilation(compilation) | |
114 , _lir(NULL) | |
115 , _pos(-1) | |
116 , _allocator(allocator) | |
117 , _sim(compilation) | |
118 , _temp_sim(compilation) | |
119 {} | |
120 | |
121 void FpuStackAllocator::allocate() { | |
122 int num_blocks = allocator()->block_count(); | |
123 for (int i = 0; i < num_blocks; i++) { | |
124 // Set up to process block | |
125 BlockBegin* block = allocator()->block_at(i); | |
126 intArray* fpu_stack_state = block->fpu_stack_state(); | |
127 | |
128 #ifndef PRODUCT | |
129 if (TraceFPUStack) { | |
130 tty->cr(); | |
131 tty->print_cr("------- Begin of new Block %d -------", block->block_id()); | |
132 } | |
133 #endif | |
134 | |
135 assert(fpu_stack_state != NULL || | |
136 block->end()->as_Base() != NULL || | |
137 block->is_set(BlockBegin::exception_entry_flag), | |
138 "FPU stack state must be present due to linear-scan order for FPU stack allocation"); | |
139 // note: exception handler entries always start with an empty fpu stack | |
140 // because stack merging would be too complicated | |
141 | |
142 if (fpu_stack_state != NULL) { | |
143 sim()->read_state(fpu_stack_state); | |
144 } else { | |
145 sim()->clear(); | |
146 } | |
147 | |
148 #ifndef PRODUCT | |
149 if (TraceFPUStack) { | |
150 tty->print("Reading FPU state for block %d:", block->block_id()); | |
151 sim()->print(); | |
152 tty->cr(); | |
153 } | |
154 #endif | |
155 | |
156 allocate_block(block); | |
157 CHECK_BAILOUT(); | |
158 } | |
159 } | |
160 | |
161 void FpuStackAllocator::allocate_block(BlockBegin* block) { | |
162 bool processed_merge = false; | |
163 LIR_OpList* insts = block->lir()->instructions_list(); | |
164 set_lir(block->lir()); | |
165 set_pos(0); | |
166 | |
167 | |
168 // Note: insts->length() may change during loop | |
169 while (pos() < insts->length()) { | |
170 LIR_Op* op = insts->at(pos()); | |
171 _debug_information_computed = false; | |
172 | |
173 #ifndef PRODUCT | |
174 if (TraceFPUStack) { | |
175 op->print(); | |
176 } | |
177 check_invalid_lir_op(op); | |
178 #endif | |
179 | |
180 LIR_OpBranch* branch = op->as_OpBranch(); | |
181 LIR_Op1* op1 = op->as_Op1(); | |
182 LIR_Op2* op2 = op->as_Op2(); | |
183 LIR_OpCall* opCall = op->as_OpCall(); | |
184 | |
185 if (branch != NULL && branch->block() != NULL) { | |
186 if (!processed_merge) { | |
187 // propagate stack at first branch to a successor | |
188 processed_merge = true; | |
189 bool required_merge = merge_fpu_stack_with_successors(block); | |
190 | |
191 assert(!required_merge || branch->cond() == lir_cond_always, "splitting of critical edges should prevent FPU stack mismatches at cond branches"); | |
192 } | |
193 | |
194 } else if (op1 != NULL) { | |
195 handle_op1(op1); | |
196 } else if (op2 != NULL) { | |
197 handle_op2(op2); | |
198 } else if (opCall != NULL) { | |
199 handle_opCall(opCall); | |
200 } | |
201 | |
202 compute_debug_information(op); | |
203 | |
204 set_pos(1 + pos()); | |
205 } | |
206 | |
207 // Propagate stack when block does not end with branch | |
208 if (!processed_merge) { | |
209 merge_fpu_stack_with_successors(block); | |
210 } | |
211 } | |
212 | |
213 | |
214 void FpuStackAllocator::compute_debug_information(LIR_Op* op) { | |
215 if (!_debug_information_computed && op->id() != -1 && allocator()->has_info(op->id())) { | |
216 visitor.visit(op); | |
217 | |
218 // exception handling | |
219 if (allocator()->compilation()->has_exception_handlers()) { | |
220 XHandlers* xhandlers = visitor.all_xhandler(); | |
221 int n = xhandlers->length(); | |
222 for (int k = 0; k < n; k++) { | |
223 allocate_exception_handler(xhandlers->handler_at(k)); | |
224 } | |
225 } else { | |
226 assert(visitor.all_xhandler()->length() == 0, "missed exception handler"); | |
227 } | |
228 | |
229 // compute debug information | |
230 int n = visitor.info_count(); | |
231 assert(n > 0, "should not visit operation otherwise"); | |
232 | |
233 for (int j = 0; j < n; j++) { | |
234 CodeEmitInfo* info = visitor.info_at(j); | |
235 // Compute debug information | |
236 allocator()->compute_debug_info(info, op->id()); | |
237 } | |
238 } | |
239 _debug_information_computed = true; | |
240 } | |
241 | |
242 void FpuStackAllocator::allocate_exception_handler(XHandler* xhandler) { | |
243 if (!sim()->is_empty()) { | |
244 LIR_List* old_lir = lir(); | |
245 int old_pos = pos(); | |
246 intArray* old_state = sim()->write_state(); | |
247 | |
248 #ifndef PRODUCT | |
249 if (TraceFPUStack) { | |
250 tty->cr(); | |
251 tty->print_cr("------- begin of exception handler -------"); | |
252 } | |
253 #endif | |
254 | |
255 if (xhandler->entry_code() == NULL) { | |
256 // need entry code to clear FPU stack | |
257 LIR_List* entry_code = new LIR_List(_compilation); | |
258 entry_code->jump(xhandler->entry_block()); | |
259 xhandler->set_entry_code(entry_code); | |
260 } | |
261 | |
262 LIR_OpList* insts = xhandler->entry_code()->instructions_list(); | |
263 set_lir(xhandler->entry_code()); | |
264 set_pos(0); | |
265 | |
266 // Note: insts->length() may change during loop | |
267 while (pos() < insts->length()) { | |
268 LIR_Op* op = insts->at(pos()); | |
269 | |
270 #ifndef PRODUCT | |
271 if (TraceFPUStack) { | |
272 op->print(); | |
273 } | |
274 check_invalid_lir_op(op); | |
275 #endif | |
276 | |
277 switch (op->code()) { | |
278 case lir_move: | |
279 assert(op->as_Op1() != NULL, "must be LIR_Op1"); | |
280 assert(pos() != insts->length() - 1, "must not be last operation"); | |
281 | |
282 handle_op1((LIR_Op1*)op); | |
283 break; | |
284 | |
285 case lir_branch: | |
286 assert(op->as_OpBranch()->cond() == lir_cond_always, "must be unconditional branch"); | |
287 assert(pos() == insts->length() - 1, "must be last operation"); | |
288 | |
289 // remove all remaining dead registers from FPU stack | |
290 clear_fpu_stack(LIR_OprFact::illegalOpr); | |
291 break; | |
292 | |
293 default: | |
294 // other operations not allowed in exception entry code | |
295 ShouldNotReachHere(); | |
296 } | |
297 | |
298 set_pos(pos() + 1); | |
299 } | |
300 | |
301 #ifndef PRODUCT | |
302 if (TraceFPUStack) { | |
303 tty->cr(); | |
304 tty->print_cr("------- end of exception handler -------"); | |
305 } | |
306 #endif | |
307 | |
308 set_lir(old_lir); | |
309 set_pos(old_pos); | |
310 sim()->read_state(old_state); | |
311 } | |
312 } | |
313 | |
314 | |
315 int FpuStackAllocator::fpu_num(LIR_Opr opr) { | |
316 assert(opr->is_fpu_register() && !opr->is_xmm_register(), "shouldn't call this otherwise"); | |
317 return opr->is_single_fpu() ? opr->fpu_regnr() : opr->fpu_regnrLo(); | |
318 } | |
319 | |
320 int FpuStackAllocator::tos_offset(LIR_Opr opr) { | |
321 return sim()->offset_from_tos(fpu_num(opr)); | |
322 } | |
323 | |
324 | |
325 LIR_Opr FpuStackAllocator::to_fpu_stack(LIR_Opr opr) { | |
326 assert(opr->is_fpu_register() && !opr->is_xmm_register(), "shouldn't call this otherwise"); | |
327 | |
328 int stack_offset = tos_offset(opr); | |
329 if (opr->is_single_fpu()) { | |
330 return LIR_OprFact::single_fpu(stack_offset)->make_fpu_stack_offset(); | |
331 } else { | |
332 assert(opr->is_double_fpu(), "shouldn't call this otherwise"); | |
333 return LIR_OprFact::double_fpu(stack_offset)->make_fpu_stack_offset(); | |
334 } | |
335 } | |
336 | |
337 LIR_Opr FpuStackAllocator::to_fpu_stack_top(LIR_Opr opr, bool dont_check_offset) { | |
338 assert(opr->is_fpu_register() && !opr->is_xmm_register(), "shouldn't call this otherwise"); | |
339 assert(dont_check_offset || tos_offset(opr) == 0, "operand is not on stack top"); | |
340 | |
341 int stack_offset = 0; | |
342 if (opr->is_single_fpu()) { | |
343 return LIR_OprFact::single_fpu(stack_offset)->make_fpu_stack_offset(); | |
344 } else { | |
345 assert(opr->is_double_fpu(), "shouldn't call this otherwise"); | |
346 return LIR_OprFact::double_fpu(stack_offset)->make_fpu_stack_offset(); | |
347 } | |
348 } | |
349 | |
350 | |
351 | |
352 void FpuStackAllocator::insert_op(LIR_Op* op) { | |
353 lir()->insert_before(pos(), op); | |
354 set_pos(1 + pos()); | |
355 } | |
356 | |
357 | |
358 void FpuStackAllocator::insert_exchange(int offset) { | |
359 if (offset > 0) { | |
360 LIR_Op1* fxch_op = new LIR_Op1(lir_fxch, LIR_OprFact::intConst(offset), LIR_OprFact::illegalOpr); | |
361 insert_op(fxch_op); | |
362 sim()->swap(offset); | |
363 | |
364 #ifndef PRODUCT | |
365 if (TraceFPUStack) { | |
366 tty->print("Exchanged register: %d New state: ", sim()->get_slot(0)); sim()->print(); tty->cr(); | |
367 } | |
368 #endif | |
369 | |
370 } | |
371 } | |
372 | |
373 void FpuStackAllocator::insert_exchange(LIR_Opr opr) { | |
374 insert_exchange(tos_offset(opr)); | |
375 } | |
376 | |
377 | |
378 void FpuStackAllocator::insert_free(int offset) { | |
379 // move stack slot to the top of stack and then pop it | |
380 insert_exchange(offset); | |
381 | |
382 LIR_Op* fpop = new LIR_Op0(lir_fpop_raw); | |
383 insert_op(fpop); | |
384 sim()->pop(); | |
385 | |
386 #ifndef PRODUCT | |
387 if (TraceFPUStack) { | |
388 tty->print("Inserted pop New state: "); sim()->print(); tty->cr(); | |
389 } | |
390 #endif | |
391 } | |
392 | |
393 | |
394 void FpuStackAllocator::insert_free_if_dead(LIR_Opr opr) { | |
395 if (sim()->contains(fpu_num(opr))) { | |
396 int res_slot = tos_offset(opr); | |
397 insert_free(res_slot); | |
398 } | |
399 } | |
400 | |
401 void FpuStackAllocator::insert_free_if_dead(LIR_Opr opr, LIR_Opr ignore) { | |
402 if (fpu_num(opr) != fpu_num(ignore) && sim()->contains(fpu_num(opr))) { | |
403 int res_slot = tos_offset(opr); | |
404 insert_free(res_slot); | |
405 } | |
406 } | |
407 | |
408 void FpuStackAllocator::insert_copy(LIR_Opr from, LIR_Opr to) { | |
409 int offset = tos_offset(from); | |
410 LIR_Op1* fld = new LIR_Op1(lir_fld, LIR_OprFact::intConst(offset), LIR_OprFact::illegalOpr); | |
411 insert_op(fld); | |
412 | |
413 sim()->push(fpu_num(to)); | |
414 | |
415 #ifndef PRODUCT | |
416 if (TraceFPUStack) { | |
417 tty->print("Inserted copy (%d -> %d) New state: ", fpu_num(from), fpu_num(to)); sim()->print(); tty->cr(); | |
418 } | |
419 #endif | |
420 } | |
421 | |
422 void FpuStackAllocator::do_rename(LIR_Opr from, LIR_Opr to) { | |
423 sim()->rename(fpu_num(from), fpu_num(to)); | |
424 } | |
425 | |
426 void FpuStackAllocator::do_push(LIR_Opr opr) { | |
427 sim()->push(fpu_num(opr)); | |
428 } | |
429 | |
430 void FpuStackAllocator::pop_if_last_use(LIR_Op* op, LIR_Opr opr) { | |
431 assert(op->fpu_pop_count() == 0, "fpu_pop_count alredy set"); | |
432 assert(tos_offset(opr) == 0, "can only pop stack top"); | |
433 | |
434 if (opr->is_last_use()) { | |
435 op->set_fpu_pop_count(1); | |
436 sim()->pop(); | |
437 } | |
438 } | |
439 | |
440 void FpuStackAllocator::pop_always(LIR_Op* op, LIR_Opr opr) { | |
441 assert(op->fpu_pop_count() == 0, "fpu_pop_count alredy set"); | |
442 assert(tos_offset(opr) == 0, "can only pop stack top"); | |
443 | |
444 op->set_fpu_pop_count(1); | |
445 sim()->pop(); | |
446 } | |
447 | |
448 void FpuStackAllocator::clear_fpu_stack(LIR_Opr preserve) { | |
449 int result_stack_size = (preserve->is_fpu_register() && !preserve->is_xmm_register() ? 1 : 0); | |
450 while (sim()->stack_size() > result_stack_size) { | |
451 assert(!sim()->slot_is_empty(0), "not allowed"); | |
452 | |
453 if (result_stack_size == 0 || sim()->get_slot(0) != fpu_num(preserve)) { | |
454 insert_free(0); | |
455 } else { | |
456 // move "preserve" to bottom of stack so that all other stack slots can be popped | |
457 insert_exchange(sim()->stack_size() - 1); | |
458 } | |
459 } | |
460 } | |
461 | |
462 | |
463 void FpuStackAllocator::handle_op1(LIR_Op1* op1) { | |
464 LIR_Opr in = op1->in_opr(); | |
465 LIR_Opr res = op1->result_opr(); | |
466 | |
467 LIR_Opr new_in = in; // new operands relative to the actual fpu stack top | |
468 LIR_Opr new_res = res; | |
469 | |
470 // Note: this switch is processed for all LIR_Op1, regardless if they have FPU-arguments, | |
471 // so checks for is_float_kind() are necessary inside the cases | |
472 switch (op1->code()) { | |
473 | |
474 case lir_return: { | |
475 // FPU-Stack must only contain the (optional) fpu return value. | |
476 // All remaining dead values are popped from the stack | |
477 // If the input operand is a fpu-register, it is exchanged to the bottom of the stack | |
478 | |
479 clear_fpu_stack(in); | |
480 if (in->is_fpu_register() && !in->is_xmm_register()) { | |
481 new_in = to_fpu_stack_top(in); | |
482 } | |
483 | |
484 break; | |
485 } | |
486 | |
487 case lir_move: { | |
488 if (in->is_fpu_register() && !in->is_xmm_register()) { | |
489 if (res->is_xmm_register()) { | |
490 // move from fpu register to xmm register (necessary for operations that | |
491 // are not available in the SSE instruction set) | |
492 insert_exchange(in); | |
493 new_in = to_fpu_stack_top(in); | |
494 pop_always(op1, in); | |
495 | |
496 } else if (res->is_fpu_register() && !res->is_xmm_register()) { | |
497 // move from fpu-register to fpu-register: | |
498 // * input and result register equal: | |
499 // nothing to do | |
500 // * input register is last use: | |
501 // rename the input register to result register -> input register | |
502 // not present on fpu-stack afterwards | |
503 // * input register not last use: | |
504 // duplicate input register to result register to preserve input | |
505 // | |
506 // Note: The LIR-Assembler does not produce any code for fpu register moves, | |
507 // so input and result stack index must be equal | |
508 | |
509 if (fpu_num(in) == fpu_num(res)) { | |
510 // nothing to do | |
511 } else if (in->is_last_use()) { | |
512 insert_free_if_dead(res);//, in); | |
513 do_rename(in, res); | |
514 } else { | |
515 insert_free_if_dead(res); | |
516 insert_copy(in, res); | |
517 } | |
518 new_in = to_fpu_stack(res); | |
519 new_res = new_in; | |
520 | |
521 } else { | |
522 // move from fpu-register to memory | |
523 // input operand must be on top of stack | |
524 | |
525 insert_exchange(in); | |
526 | |
527 // create debug information here because afterwards the register may have been popped | |
528 compute_debug_information(op1); | |
529 | |
530 new_in = to_fpu_stack_top(in); | |
531 pop_if_last_use(op1, in); | |
532 } | |
533 | |
534 } else if (res->is_fpu_register() && !res->is_xmm_register()) { | |
535 // move from memory/constant to fpu register | |
536 // result is pushed on the stack | |
537 | |
538 insert_free_if_dead(res); | |
539 | |
540 // create debug information before register is pushed | |
541 compute_debug_information(op1); | |
542 | |
543 do_push(res); | |
544 new_res = to_fpu_stack_top(res); | |
545 } | |
546 break; | |
547 } | |
548 | |
549 case lir_neg: { | |
550 if (in->is_fpu_register() && !in->is_xmm_register()) { | |
551 assert(res->is_fpu_register() && !res->is_xmm_register(), "must be"); | |
552 assert(in->is_last_use(), "old value gets destroyed"); | |
553 | |
554 insert_free_if_dead(res, in); | |
555 insert_exchange(in); | |
556 new_in = to_fpu_stack_top(in); | |
557 | |
558 do_rename(in, res); | |
559 new_res = to_fpu_stack_top(res); | |
560 } | |
561 break; | |
562 } | |
563 | |
564 case lir_convert: { | |
565 Bytecodes::Code bc = op1->as_OpConvert()->bytecode(); | |
566 switch (bc) { | |
567 case Bytecodes::_d2f: | |
568 case Bytecodes::_f2d: | |
569 assert(res->is_fpu_register(), "must be"); | |
570 assert(in->is_fpu_register(), "must be"); | |
571 | |
572 if (!in->is_xmm_register() && !res->is_xmm_register()) { | |
573 // this is quite the same as a move from fpu-register to fpu-register | |
574 // Note: input and result operands must have different types | |
575 if (fpu_num(in) == fpu_num(res)) { | |
576 // nothing to do | |
577 new_in = to_fpu_stack(in); | |
578 } else if (in->is_last_use()) { | |
579 insert_free_if_dead(res);//, in); | |
580 new_in = to_fpu_stack(in); | |
581 do_rename(in, res); | |
582 } else { | |
583 insert_free_if_dead(res); | |
584 insert_copy(in, res); | |
585 new_in = to_fpu_stack_top(in, true); | |
586 } | |
587 new_res = to_fpu_stack(res); | |
588 } | |
589 | |
590 break; | |
591 | |
592 case Bytecodes::_i2f: | |
593 case Bytecodes::_l2f: | |
594 case Bytecodes::_i2d: | |
595 case Bytecodes::_l2d: | |
596 assert(res->is_fpu_register(), "must be"); | |
597 if (!res->is_xmm_register()) { | |
598 insert_free_if_dead(res); | |
599 do_push(res); | |
600 new_res = to_fpu_stack_top(res); | |
601 } | |
602 break; | |
603 | |
604 case Bytecodes::_f2i: | |
605 case Bytecodes::_d2i: | |
606 assert(in->is_fpu_register(), "must be"); | |
607 if (!in->is_xmm_register()) { | |
608 insert_exchange(in); | |
609 new_in = to_fpu_stack_top(in); | |
610 | |
611 // TODO: update registes of stub | |
612 } | |
613 break; | |
614 | |
615 case Bytecodes::_f2l: | |
616 case Bytecodes::_d2l: | |
617 assert(in->is_fpu_register(), "must be"); | |
618 if (!in->is_xmm_register()) { | |
619 insert_exchange(in); | |
620 new_in = to_fpu_stack_top(in); | |
621 pop_always(op1, in); | |
622 } | |
623 break; | |
624 | |
625 case Bytecodes::_i2l: | |
626 case Bytecodes::_l2i: | |
627 case Bytecodes::_i2b: | |
628 case Bytecodes::_i2c: | |
629 case Bytecodes::_i2s: | |
630 // no fpu operands | |
631 break; | |
632 | |
633 default: | |
634 ShouldNotReachHere(); | |
635 } | |
636 break; | |
637 } | |
638 | |
639 case lir_roundfp: { | |
640 assert(in->is_fpu_register() && !in->is_xmm_register(), "input must be in register"); | |
641 assert(res->is_stack(), "result must be on stack"); | |
642 | |
643 insert_exchange(in); | |
644 new_in = to_fpu_stack_top(in); | |
645 pop_if_last_use(op1, in); | |
646 break; | |
647 } | |
648 | |
649 default: { | |
650 assert(!in->is_float_kind() && !res->is_float_kind(), "missed a fpu-operation"); | |
651 } | |
652 } | |
653 | |
654 op1->set_in_opr(new_in); | |
655 op1->set_result_opr(new_res); | |
656 } | |
657 | |
658 void FpuStackAllocator::handle_op2(LIR_Op2* op2) { | |
659 LIR_Opr left = op2->in_opr1(); | |
660 if (!left->is_float_kind()) { | |
661 return; | |
662 } | |
663 if (left->is_xmm_register()) { | |
664 return; | |
665 } | |
666 | |
667 LIR_Opr right = op2->in_opr2(); | |
668 LIR_Opr res = op2->result_opr(); | |
669 LIR_Opr new_left = left; // new operands relative to the actual fpu stack top | |
670 LIR_Opr new_right = right; | |
671 LIR_Opr new_res = res; | |
672 | |
673 assert(!left->is_xmm_register() && !right->is_xmm_register() && !res->is_xmm_register(), "not for xmm registers"); | |
674 | |
675 switch (op2->code()) { | |
676 case lir_cmp: | |
677 case lir_cmp_fd2i: | |
678 case lir_ucmp_fd2i: { | |
679 assert(left->is_fpu_register(), "invalid LIR"); | |
680 assert(right->is_fpu_register(), "invalid LIR"); | |
681 | |
682 // the left-hand side must be on top of stack. | |
683 // the right-hand side is never popped, even if is_last_use is set | |
684 insert_exchange(left); | |
685 new_left = to_fpu_stack_top(left); | |
686 new_right = to_fpu_stack(right); | |
687 pop_if_last_use(op2, left); | |
688 break; | |
689 } | |
690 | |
691 case lir_mul_strictfp: | |
692 case lir_div_strictfp: { | |
693 assert(op2->tmp_opr()->is_fpu_register(), "strict operations need temporary fpu stack slot"); | |
694 insert_free_if_dead(op2->tmp_opr()); | |
695 assert(sim()->stack_size() <= 7, "at least one stack slot must be free"); | |
696 // fall-through: continue with the normal handling of lir_mul and lir_div | |
697 } | |
698 case lir_add: | |
699 case lir_sub: | |
700 case lir_mul: | |
701 case lir_div: { | |
702 assert(left->is_fpu_register(), "must be"); | |
703 assert(res->is_fpu_register(), "must be"); | |
704 assert(left->is_equal(res), "must be"); | |
705 | |
706 // either the left-hand or the right-hand side must be on top of stack | |
707 // (if right is not a register, left must be on top) | |
708 if (!right->is_fpu_register()) { | |
709 insert_exchange(left); | |
710 new_left = to_fpu_stack_top(left); | |
711 } else { | |
712 // no exchange necessary if right is alredy on top of stack | |
713 if (tos_offset(right) == 0) { | |
714 new_left = to_fpu_stack(left); | |
715 new_right = to_fpu_stack_top(right); | |
716 } else { | |
717 insert_exchange(left); | |
718 new_left = to_fpu_stack_top(left); | |
719 new_right = to_fpu_stack(right); | |
720 } | |
721 | |
722 if (right->is_last_use()) { | |
723 op2->set_fpu_pop_count(1); | |
724 | |
725 if (tos_offset(right) == 0) { | |
726 sim()->pop(); | |
727 } else { | |
728 // if left is on top of stack, the result is placed in the stack | |
729 // slot of right, so a renaming from right to res is necessary | |
730 assert(tos_offset(left) == 0, "must be"); | |
731 sim()->pop(); | |
732 do_rename(right, res); | |
733 } | |
734 } | |
735 } | |
736 new_res = to_fpu_stack(res); | |
737 | |
738 break; | |
739 } | |
740 | |
741 case lir_rem: { | |
742 assert(left->is_fpu_register(), "must be"); | |
743 assert(right->is_fpu_register(), "must be"); | |
744 assert(res->is_fpu_register(), "must be"); | |
745 assert(left->is_equal(res), "must be"); | |
746 | |
747 // Must bring both operands to top of stack with following operand ordering: | |
748 // * fpu stack before rem: ... right left | |
749 // * fpu stack after rem: ... left | |
750 if (tos_offset(right) != 1) { | |
751 insert_exchange(right); | |
752 insert_exchange(1); | |
753 } | |
754 insert_exchange(left); | |
755 assert(tos_offset(right) == 1, "check"); | |
756 assert(tos_offset(left) == 0, "check"); | |
757 | |
758 new_left = to_fpu_stack_top(left); | |
759 new_right = to_fpu_stack(right); | |
760 | |
761 op2->set_fpu_pop_count(1); | |
762 sim()->pop(); | |
763 do_rename(right, res); | |
764 | |
765 new_res = to_fpu_stack_top(res); | |
766 break; | |
767 } | |
768 | |
769 case lir_abs: | |
770 case lir_sqrt: { | |
771 // Right argument appears to be unused | |
772 assert(right->is_illegal(), "must be"); | |
773 assert(left->is_fpu_register(), "must be"); | |
774 assert(res->is_fpu_register(), "must be"); | |
775 assert(left->is_last_use(), "old value gets destroyed"); | |
776 | |
777 insert_free_if_dead(res, left); | |
778 insert_exchange(left); | |
779 do_rename(left, res); | |
780 | |
781 new_left = to_fpu_stack_top(res); | |
782 new_res = new_left; | |
783 | |
784 op2->set_fpu_stack_size(sim()->stack_size()); | |
785 break; | |
786 } | |
787 | |
953
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
788 case lir_log: |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
789 case lir_log10: { |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
790 // log and log10 needs one temporary fpu stack slot, so there is ontemporary |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
791 // registers stored in temp of the operation. |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
792 // the stack allocator must guarantee that the stack slots are really free, |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
793 // otherwise there might be a stack overflow. |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
794 assert(right->is_illegal(), "must be"); |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
795 assert(left->is_fpu_register(), "must be"); |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
796 assert(res->is_fpu_register(), "must be"); |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
797 assert(op2->tmp_opr()->is_fpu_register(), "must be"); |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
798 |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
799 insert_free_if_dead(op2->tmp_opr()); |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
800 insert_free_if_dead(res, left); |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
801 insert_exchange(left); |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
802 do_rename(left, res); |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
803 |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
804 new_left = to_fpu_stack_top(res); |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
805 new_res = new_left; |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
806 |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
807 op2->set_fpu_stack_size(sim()->stack_size()); |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
808 assert(sim()->stack_size() <= 7, "at least one stack slot must be free"); |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
809 break; |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
810 } |
ff1a29907b6c
6855215: Calculation error (NaN) after about 1500 calculations
never
parents:
0
diff
changeset
|
811 |
0 | 812 |
813 case lir_tan: | |
814 case lir_sin: | |
815 case lir_cos: { | |
816 // sin and cos need two temporary fpu stack slots, so there are two temporary | |
817 // registers (stored in right and temp of the operation). | |
818 // the stack allocator must guarantee that the stack slots are really free, | |
819 // otherwise there might be a stack overflow. | |
820 assert(left->is_fpu_register(), "must be"); | |
821 assert(res->is_fpu_register(), "must be"); | |
822 // assert(left->is_last_use(), "old value gets destroyed"); | |
823 assert(right->is_fpu_register(), "right is used as the first temporary register"); | |
824 assert(op2->tmp_opr()->is_fpu_register(), "temp is used as the second temporary register"); | |
825 assert(fpu_num(left) != fpu_num(right) && fpu_num(right) != fpu_num(op2->tmp_opr()) && fpu_num(op2->tmp_opr()) != fpu_num(res), "need distinct temp registers"); | |
826 | |
827 insert_free_if_dead(right); | |
828 insert_free_if_dead(op2->tmp_opr()); | |
829 | |
830 insert_free_if_dead(res, left); | |
831 insert_exchange(left); | |
832 do_rename(left, res); | |
833 | |
834 new_left = to_fpu_stack_top(res); | |
835 new_res = new_left; | |
836 | |
837 op2->set_fpu_stack_size(sim()->stack_size()); | |
838 assert(sim()->stack_size() <= 6, "at least two stack slots must be free"); | |
839 break; | |
840 } | |
841 | |
842 default: { | |
843 assert(false, "missed a fpu-operation"); | |
844 } | |
845 } | |
846 | |
847 op2->set_in_opr1(new_left); | |
848 op2->set_in_opr2(new_right); | |
849 op2->set_result_opr(new_res); | |
850 } | |
851 | |
852 void FpuStackAllocator::handle_opCall(LIR_OpCall* opCall) { | |
853 LIR_Opr res = opCall->result_opr(); | |
854 | |
855 // clear fpu-stack before call | |
856 // it may contain dead values that could not have been remved by previous operations | |
857 clear_fpu_stack(LIR_OprFact::illegalOpr); | |
858 assert(sim()->is_empty(), "fpu stack must be empty now"); | |
859 | |
860 // compute debug information before (possible) fpu result is pushed | |
861 compute_debug_information(opCall); | |
862 | |
863 if (res->is_fpu_register() && !res->is_xmm_register()) { | |
864 do_push(res); | |
865 opCall->set_result_opr(to_fpu_stack_top(res)); | |
866 } | |
867 } | |
868 | |
869 #ifndef PRODUCT | |
870 void FpuStackAllocator::check_invalid_lir_op(LIR_Op* op) { | |
871 switch (op->code()) { | |
872 case lir_24bit_FPU: | |
873 case lir_reset_FPU: | |
874 case lir_ffree: | |
875 assert(false, "operations not allowed in lir. If one of these operations is needed, check if they have fpu operands"); | |
876 break; | |
877 | |
878 case lir_fpop_raw: | |
879 case lir_fxch: | |
880 case lir_fld: | |
881 assert(false, "operations only inserted by FpuStackAllocator"); | |
882 break; | |
883 } | |
884 } | |
885 #endif | |
886 | |
887 | |
888 void FpuStackAllocator::merge_insert_add(LIR_List* instrs, FpuStackSim* cur_sim, int reg) { | |
889 LIR_Op1* move = new LIR_Op1(lir_move, LIR_OprFact::doubleConst(0), LIR_OprFact::double_fpu(reg)->make_fpu_stack_offset()); | |
890 | |
891 instrs->instructions_list()->push(move); | |
892 | |
893 cur_sim->push(reg); | |
894 move->set_result_opr(to_fpu_stack(move->result_opr())); | |
895 | |
896 #ifndef PRODUCT | |
897 if (TraceFPUStack) { | |
898 tty->print("Added new register: %d New state: ", reg); cur_sim->print(); tty->cr(); | |
899 } | |
900 #endif | |
901 } | |
902 | |
903 void FpuStackAllocator::merge_insert_xchg(LIR_List* instrs, FpuStackSim* cur_sim, int slot) { | |
904 assert(slot > 0, "no exchange necessary"); | |
905 | |
906 LIR_Op1* fxch = new LIR_Op1(lir_fxch, LIR_OprFact::intConst(slot)); | |
907 instrs->instructions_list()->push(fxch); | |
908 cur_sim->swap(slot); | |
909 | |
910 #ifndef PRODUCT | |
911 if (TraceFPUStack) { | |
912 tty->print("Exchanged register: %d New state: ", cur_sim->get_slot(slot)); cur_sim->print(); tty->cr(); | |
913 } | |
914 #endif | |
915 } | |
916 | |
917 void FpuStackAllocator::merge_insert_pop(LIR_List* instrs, FpuStackSim* cur_sim) { | |
918 int reg = cur_sim->get_slot(0); | |
919 | |
920 LIR_Op* fpop = new LIR_Op0(lir_fpop_raw); | |
921 instrs->instructions_list()->push(fpop); | |
922 cur_sim->pop(reg); | |
923 | |
924 #ifndef PRODUCT | |
925 if (TraceFPUStack) { | |
926 tty->print("Removed register: %d New state: ", reg); cur_sim->print(); tty->cr(); | |
927 } | |
928 #endif | |
929 } | |
930 | |
931 bool FpuStackAllocator::merge_rename(FpuStackSim* cur_sim, FpuStackSim* sux_sim, int start_slot, int change_slot) { | |
932 int reg = cur_sim->get_slot(change_slot); | |
933 | |
934 for (int slot = start_slot; slot >= 0; slot--) { | |
935 int new_reg = sux_sim->get_slot(slot); | |
936 | |
937 if (!cur_sim->contains(new_reg)) { | |
938 cur_sim->set_slot(change_slot, new_reg); | |
939 | |
940 #ifndef PRODUCT | |
941 if (TraceFPUStack) { | |
942 tty->print("Renamed register %d to %d New state: ", reg, new_reg); cur_sim->print(); tty->cr(); | |
943 } | |
944 #endif | |
945 | |
946 return true; | |
947 } | |
948 } | |
949 return false; | |
950 } | |
951 | |
952 | |
953 void FpuStackAllocator::merge_fpu_stack(LIR_List* instrs, FpuStackSim* cur_sim, FpuStackSim* sux_sim) { | |
954 #ifndef PRODUCT | |
955 if (TraceFPUStack) { | |
956 tty->cr(); | |
957 tty->print("before merging: pred: "); cur_sim->print(); tty->cr(); | |
958 tty->print(" sux: "); sux_sim->print(); tty->cr(); | |
959 } | |
960 | |
961 int slot; | |
962 for (slot = 0; slot < cur_sim->stack_size(); slot++) { | |
963 assert(!cur_sim->slot_is_empty(slot), "not handled by algorithm"); | |
964 } | |
965 for (slot = 0; slot < sux_sim->stack_size(); slot++) { | |
966 assert(!sux_sim->slot_is_empty(slot), "not handled by algorithm"); | |
967 } | |
968 #endif | |
969 | |
970 // size difference between cur and sux that must be resolved by adding or removing values form the stack | |
971 int size_diff = cur_sim->stack_size() - sux_sim->stack_size(); | |
972 | |
973 if (!ComputeExactFPURegisterUsage) { | |
974 // add slots that are currently free, but used in successor | |
975 // When the exact FPU register usage is computed, the stack does | |
976 // not contain dead values at merging -> no values must be added | |
977 | |
978 int sux_slot = sux_sim->stack_size() - 1; | |
979 while (size_diff < 0) { | |
980 assert(sux_slot >= 0, "slot out of bounds -> error in algorithm"); | |
981 | |
982 int reg = sux_sim->get_slot(sux_slot); | |
983 if (!cur_sim->contains(reg)) { | |
984 merge_insert_add(instrs, cur_sim, reg); | |
985 size_diff++; | |
986 | |
987 if (sux_slot + size_diff != 0) { | |
988 merge_insert_xchg(instrs, cur_sim, sux_slot + size_diff); | |
989 } | |
990 } | |
991 sux_slot--; | |
992 } | |
993 } | |
994 | |
995 assert(cur_sim->stack_size() >= sux_sim->stack_size(), "stack size must be equal or greater now"); | |
996 assert(size_diff == cur_sim->stack_size() - sux_sim->stack_size(), "must be"); | |
997 | |
998 // stack merge algorithm: | |
999 // 1) as long as the current stack top is not in the right location (that meens | |
1000 // it should not be on the stack top), exchange it into the right location | |
1001 // 2) if the stack top is right, but the remaining stack is not ordered correctly, | |
1002 // the stack top is exchanged away to get another value on top -> | |
1003 // now step 1) can be continued | |
1004 // the stack can also contain unused items -> these items are removed from stack | |
1005 | |
1006 int finished_slot = sux_sim->stack_size() - 1; | |
1007 while (finished_slot >= 0 || size_diff > 0) { | |
1008 while (size_diff > 0 || (cur_sim->stack_size() > 0 && cur_sim->get_slot(0) != sux_sim->get_slot(0))) { | |
1009 int reg = cur_sim->get_slot(0); | |
1010 if (sux_sim->contains(reg)) { | |
1011 int sux_slot = sux_sim->offset_from_tos(reg); | |
1012 merge_insert_xchg(instrs, cur_sim, sux_slot + size_diff); | |
1013 | |
1014 } else if (!merge_rename(cur_sim, sux_sim, finished_slot, 0)) { | |
1015 assert(size_diff > 0, "must be"); | |
1016 | |
1017 merge_insert_pop(instrs, cur_sim); | |
1018 size_diff--; | |
1019 } | |
1020 assert(cur_sim->stack_size() == 0 || cur_sim->get_slot(0) != reg, "register must have been changed"); | |
1021 } | |
1022 | |
1023 while (finished_slot >= 0 && cur_sim->get_slot(finished_slot) == sux_sim->get_slot(finished_slot)) { | |
1024 finished_slot--; | |
1025 } | |
1026 | |
1027 if (finished_slot >= 0) { | |
1028 int reg = cur_sim->get_slot(finished_slot); | |
1029 | |
1030 if (sux_sim->contains(reg) || !merge_rename(cur_sim, sux_sim, finished_slot, finished_slot)) { | |
1031 assert(sux_sim->contains(reg) || size_diff > 0, "must be"); | |
1032 merge_insert_xchg(instrs, cur_sim, finished_slot); | |
1033 } | |
1034 assert(cur_sim->get_slot(finished_slot) != reg, "register must have been changed"); | |
1035 } | |
1036 } | |
1037 | |
1038 #ifndef PRODUCT | |
1039 if (TraceFPUStack) { | |
1040 tty->print("after merging: pred: "); cur_sim->print(); tty->cr(); | |
1041 tty->print(" sux: "); sux_sim->print(); tty->cr(); | |
1042 tty->cr(); | |
1043 } | |
1044 #endif | |
1045 assert(cur_sim->stack_size() == sux_sim->stack_size(), "stack size must be equal now"); | |
1046 } | |
1047 | |
1048 | |
1049 void FpuStackAllocator::merge_cleanup_fpu_stack(LIR_List* instrs, FpuStackSim* cur_sim, BitMap& live_fpu_regs) { | |
1050 #ifndef PRODUCT | |
1051 if (TraceFPUStack) { | |
1052 tty->cr(); | |
1053 tty->print("before cleanup: state: "); cur_sim->print(); tty->cr(); | |
1054 tty->print(" live: "); live_fpu_regs.print_on(tty); tty->cr(); | |
1055 } | |
1056 #endif | |
1057 | |
1058 int slot = 0; | |
1059 while (slot < cur_sim->stack_size()) { | |
1060 int reg = cur_sim->get_slot(slot); | |
1061 if (!live_fpu_regs.at(reg)) { | |
1062 if (slot != 0) { | |
1063 merge_insert_xchg(instrs, cur_sim, slot); | |
1064 } | |
1065 merge_insert_pop(instrs, cur_sim); | |
1066 } else { | |
1067 slot++; | |
1068 } | |
1069 } | |
1070 | |
1071 #ifndef PRODUCT | |
1072 if (TraceFPUStack) { | |
1073 tty->print("after cleanup: state: "); cur_sim->print(); tty->cr(); | |
1074 tty->print(" live: "); live_fpu_regs.print_on(tty); tty->cr(); | |
1075 tty->cr(); | |
1076 } | |
1077 | |
1078 // check if fpu stack only contains live registers | |
1079 for (unsigned int i = 0; i < live_fpu_regs.size(); i++) { | |
1080 if (live_fpu_regs.at(i) != cur_sim->contains(i)) { | |
1081 tty->print_cr("mismatch between required and actual stack content"); | |
1082 break; | |
1083 } | |
1084 } | |
1085 #endif | |
1086 } | |
1087 | |
1088 | |
1089 bool FpuStackAllocator::merge_fpu_stack_with_successors(BlockBegin* block) { | |
1090 #ifndef PRODUCT | |
1091 if (TraceFPUStack) { | |
1092 tty->print_cr("Propagating FPU stack state for B%d at LIR_Op position %d to successors:", | |
1093 block->block_id(), pos()); | |
1094 sim()->print(); | |
1095 tty->cr(); | |
1096 } | |
1097 #endif | |
1098 | |
1099 bool changed = false; | |
1100 int number_of_sux = block->number_of_sux(); | |
1101 | |
1102 if (number_of_sux == 1 && block->sux_at(0)->number_of_preds() > 1) { | |
1103 // The successor has at least two incoming edges, so a stack merge will be necessary | |
1104 // If this block is the first predecessor, cleanup the current stack and propagate it | |
1105 // If this block is not the first predecessor, a stack merge will be necessary | |
1106 | |
1107 BlockBegin* sux = block->sux_at(0); | |
1108 intArray* state = sux->fpu_stack_state(); | |
1109 LIR_List* instrs = new LIR_List(_compilation); | |
1110 | |
1111 if (state != NULL) { | |
1112 // Merge with a successors that already has a FPU stack state | |
1113 // the block must only have one successor because critical edges must been split | |
1114 FpuStackSim* cur_sim = sim(); | |
1115 FpuStackSim* sux_sim = temp_sim(); | |
1116 sux_sim->read_state(state); | |
1117 | |
1118 merge_fpu_stack(instrs, cur_sim, sux_sim); | |
1119 | |
1120 } else { | |
1121 // propagate current FPU stack state to successor without state | |
1122 // clean up stack first so that there are no dead values on the stack | |
1123 if (ComputeExactFPURegisterUsage) { | |
1124 FpuStackSim* cur_sim = sim(); | |
1125 BitMap live_fpu_regs = block->sux_at(0)->fpu_register_usage(); | |
1126 assert(live_fpu_regs.size() == FrameMap::nof_fpu_regs, "missing register usage"); | |
1127 | |
1128 merge_cleanup_fpu_stack(instrs, cur_sim, live_fpu_regs); | |
1129 } | |
1130 | |
1131 intArray* state = sim()->write_state(); | |
1132 if (TraceFPUStack) { | |
1133 tty->print_cr("Setting FPU stack state of B%d (merge path)", sux->block_id()); | |
1134 sim()->print(); tty->cr(); | |
1135 } | |
1136 sux->set_fpu_stack_state(state); | |
1137 } | |
1138 | |
1139 if (instrs->instructions_list()->length() > 0) { | |
1140 lir()->insert_before(pos(), instrs); | |
1141 set_pos(instrs->instructions_list()->length() + pos()); | |
1142 changed = true; | |
1143 } | |
1144 | |
1145 } else { | |
1146 // Propagate unmodified Stack to successors where a stack merge is not necessary | |
1147 intArray* state = sim()->write_state(); | |
1148 for (int i = 0; i < number_of_sux; i++) { | |
1149 BlockBegin* sux = block->sux_at(i); | |
1150 | |
1151 #ifdef ASSERT | |
1152 for (int j = 0; j < sux->number_of_preds(); j++) { | |
1153 assert(block == sux->pred_at(j), "all critical edges must be broken"); | |
1154 } | |
1155 | |
1156 // check if new state is same | |
1157 if (sux->fpu_stack_state() != NULL) { | |
1158 intArray* sux_state = sux->fpu_stack_state(); | |
1159 assert(state->length() == sux_state->length(), "overwriting existing stack state"); | |
1160 for (int j = 0; j < state->length(); j++) { | |
1161 assert(state->at(j) == sux_state->at(j), "overwriting existing stack state"); | |
1162 } | |
1163 } | |
1164 #endif | |
1165 #ifndef PRODUCT | |
1166 if (TraceFPUStack) { | |
1167 tty->print_cr("Setting FPU stack state of B%d", sux->block_id()); | |
1168 sim()->print(); tty->cr(); | |
1169 } | |
1170 #endif | |
1171 | |
1172 sux->set_fpu_stack_state(state); | |
1173 } | |
1174 } | |
1175 | |
1176 #ifndef PRODUCT | |
1177 // assertions that FPU stack state conforms to all successors' states | |
1178 intArray* cur_state = sim()->write_state(); | |
1179 for (int i = 0; i < number_of_sux; i++) { | |
1180 BlockBegin* sux = block->sux_at(i); | |
1181 intArray* sux_state = sux->fpu_stack_state(); | |
1182 | |
1183 assert(sux_state != NULL, "no fpu state"); | |
1184 assert(cur_state->length() == sux_state->length(), "incorrect length"); | |
1185 for (int i = 0; i < cur_state->length(); i++) { | |
1186 assert(cur_state->at(i) == sux_state->at(i), "element not equal"); | |
1187 } | |
1188 } | |
1189 #endif | |
1190 | |
1191 return changed; | |
1192 } |