1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/src/cpu/x86/vm/c1_LinearScan_x86.cpp Wed Apr 27 01:25:04 2016 +0800 1.3 @@ -0,0 +1,1242 @@ 1.4 +/* 1.5 + * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved. 1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 1.7 + * 1.8 + * This code is free software; you can redistribute it and/or modify it 1.9 + * under the terms of the GNU General Public License version 2 only, as 1.10 + * published by the Free Software Foundation. 1.11 + * 1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT 1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 1.15 + * version 2 for more details (a copy is included in the LICENSE file that 1.16 + * accompanied this code). 1.17 + * 1.18 + * You should have received a copy of the GNU General Public License version 1.19 + * 2 along with this work; if not, write to the Free Software Foundation, 1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 1.21 + * 1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 1.23 + * or visit www.oracle.com if you need additional information or have any 1.24 + * questions. 1.25 + * 1.26 + */ 1.27 + 1.28 +#include "precompiled.hpp" 1.29 +#include "c1/c1_Instruction.hpp" 1.30 +#include "c1/c1_LinearScan.hpp" 1.31 +#include "utilities/bitMap.inline.hpp" 1.32 + 1.33 + 1.34 +//---------------------------------------------------------------------- 1.35 +// Allocation of FPU stack slots (Intel x86 only) 1.36 +//---------------------------------------------------------------------- 1.37 + 1.38 +void LinearScan::allocate_fpu_stack() { 1.39 + // First compute which FPU registers are live at the start of each basic block 1.40 + // (To minimize the amount of work we have to do if we have to merge FPU stacks) 1.41 + if (ComputeExactFPURegisterUsage) { 1.42 + Interval* intervals_in_register, *intervals_in_memory; 1.43 + create_unhandled_lists(&intervals_in_register, &intervals_in_memory, is_in_fpu_register, NULL); 1.44 + 1.45 + // ignore memory intervals by overwriting intervals_in_memory 1.46 + // the dummy interval is needed to enforce the walker to walk until the given id: 1.47 + // without it, the walker stops when the unhandled-list is empty -> live information 1.48 + // beyond this point would be incorrect. 1.49 + Interval* dummy_interval = new Interval(any_reg); 1.50 + dummy_interval->add_range(max_jint - 2, max_jint - 1); 1.51 + dummy_interval->set_next(Interval::end()); 1.52 + intervals_in_memory = dummy_interval; 1.53 + 1.54 + IntervalWalker iw(this, intervals_in_register, intervals_in_memory); 1.55 + 1.56 + const int num_blocks = block_count(); 1.57 + for (int i = 0; i < num_blocks; i++) { 1.58 + BlockBegin* b = block_at(i); 1.59 + 1.60 + // register usage is only needed for merging stacks -> compute only 1.61 + // when more than one predecessor. 1.62 + // the block must not have any spill moves at the beginning (checked by assertions) 1.63 + // spill moves would use intervals that are marked as handled and so the usage bit 1.64 + // would been set incorrectly 1.65 + 1.66 + // NOTE: the check for number_of_preds > 1 is necessary. A block with only one 1.67 + // predecessor may have spill moves at the begin of the block. 1.68 + // If an interval ends at the current instruction id, it is not possible 1.69 + // to decide if the register is live or not at the block begin -> the 1.70 + // register information would be incorrect. 1.71 + if (b->number_of_preds() > 1) { 1.72 + int id = b->first_lir_instruction_id(); 1.73 + BitMap regs(FrameMap::nof_fpu_regs); 1.74 + regs.clear(); 1.75 + 1.76 + iw.walk_to(id); // walk after the first instruction (always a label) of the block 1.77 + assert(iw.current_position() == id, "did not walk completely to id"); 1.78 + 1.79 + // Only consider FPU values in registers 1.80 + Interval* interval = iw.active_first(fixedKind); 1.81 + while (interval != Interval::end()) { 1.82 + int reg = interval->assigned_reg(); 1.83 + assert(reg >= pd_first_fpu_reg && reg <= pd_last_fpu_reg, "no fpu register"); 1.84 + assert(interval->assigned_regHi() == -1, "must not have hi register (doubles stored in one register)"); 1.85 + assert(interval->from() <= id && id < interval->to(), "interval out of range"); 1.86 + 1.87 +#ifndef PRODUCT 1.88 + if (TraceFPURegisterUsage) { 1.89 + tty->print("fpu reg %d is live because of ", reg - pd_first_fpu_reg); interval->print(); 1.90 + } 1.91 +#endif 1.92 + 1.93 + regs.set_bit(reg - pd_first_fpu_reg); 1.94 + interval = interval->next(); 1.95 + } 1.96 + 1.97 + b->set_fpu_register_usage(regs); 1.98 + 1.99 +#ifndef PRODUCT 1.100 + if (TraceFPURegisterUsage) { 1.101 + tty->print("FPU regs for block %d, LIR instr %d): ", b->block_id(), id); regs.print_on(tty); tty->cr(); 1.102 + } 1.103 +#endif 1.104 + } 1.105 + } 1.106 + } 1.107 + 1.108 + FpuStackAllocator alloc(ir()->compilation(), this); 1.109 + _fpu_stack_allocator = &alloc; 1.110 + alloc.allocate(); 1.111 + _fpu_stack_allocator = NULL; 1.112 +} 1.113 + 1.114 + 1.115 +FpuStackAllocator::FpuStackAllocator(Compilation* compilation, LinearScan* allocator) 1.116 + : _compilation(compilation) 1.117 + , _lir(NULL) 1.118 + , _pos(-1) 1.119 + , _allocator(allocator) 1.120 + , _sim(compilation) 1.121 + , _temp_sim(compilation) 1.122 +{} 1.123 + 1.124 +void FpuStackAllocator::allocate() { 1.125 + int num_blocks = allocator()->block_count(); 1.126 + for (int i = 0; i < num_blocks; i++) { 1.127 + // Set up to process block 1.128 + BlockBegin* block = allocator()->block_at(i); 1.129 + intArray* fpu_stack_state = block->fpu_stack_state(); 1.130 + 1.131 +#ifndef PRODUCT 1.132 + if (TraceFPUStack) { 1.133 + tty->cr(); 1.134 + tty->print_cr("------- Begin of new Block %d -------", block->block_id()); 1.135 + } 1.136 +#endif 1.137 + 1.138 + assert(fpu_stack_state != NULL || 1.139 + block->end()->as_Base() != NULL || 1.140 + block->is_set(BlockBegin::exception_entry_flag), 1.141 + "FPU stack state must be present due to linear-scan order for FPU stack allocation"); 1.142 + // note: exception handler entries always start with an empty fpu stack 1.143 + // because stack merging would be too complicated 1.144 + 1.145 + if (fpu_stack_state != NULL) { 1.146 + sim()->read_state(fpu_stack_state); 1.147 + } else { 1.148 + sim()->clear(); 1.149 + } 1.150 + 1.151 +#ifndef PRODUCT 1.152 + if (TraceFPUStack) { 1.153 + tty->print("Reading FPU state for block %d:", block->block_id()); 1.154 + sim()->print(); 1.155 + tty->cr(); 1.156 + } 1.157 +#endif 1.158 + 1.159 + allocate_block(block); 1.160 + CHECK_BAILOUT(); 1.161 + } 1.162 +} 1.163 + 1.164 +void FpuStackAllocator::allocate_block(BlockBegin* block) { 1.165 + bool processed_merge = false; 1.166 + LIR_OpList* insts = block->lir()->instructions_list(); 1.167 + set_lir(block->lir()); 1.168 + set_pos(0); 1.169 + 1.170 + 1.171 + // Note: insts->length() may change during loop 1.172 + while (pos() < insts->length()) { 1.173 + LIR_Op* op = insts->at(pos()); 1.174 + _debug_information_computed = false; 1.175 + 1.176 +#ifndef PRODUCT 1.177 + if (TraceFPUStack) { 1.178 + op->print(); 1.179 + } 1.180 + check_invalid_lir_op(op); 1.181 +#endif 1.182 + 1.183 + LIR_OpBranch* branch = op->as_OpBranch(); 1.184 + LIR_Op1* op1 = op->as_Op1(); 1.185 + LIR_Op2* op2 = op->as_Op2(); 1.186 + LIR_OpCall* opCall = op->as_OpCall(); 1.187 + 1.188 + if (branch != NULL && branch->block() != NULL) { 1.189 + if (!processed_merge) { 1.190 + // propagate stack at first branch to a successor 1.191 + processed_merge = true; 1.192 + bool required_merge = merge_fpu_stack_with_successors(block); 1.193 + 1.194 + assert(!required_merge || branch->cond() == lir_cond_always, "splitting of critical edges should prevent FPU stack mismatches at cond branches"); 1.195 + } 1.196 + 1.197 + } else if (op1 != NULL) { 1.198 + handle_op1(op1); 1.199 + } else if (op2 != NULL) { 1.200 + handle_op2(op2); 1.201 + } else if (opCall != NULL) { 1.202 + handle_opCall(opCall); 1.203 + } 1.204 + 1.205 + compute_debug_information(op); 1.206 + 1.207 + set_pos(1 + pos()); 1.208 + } 1.209 + 1.210 + // Propagate stack when block does not end with branch 1.211 + if (!processed_merge) { 1.212 + merge_fpu_stack_with_successors(block); 1.213 + } 1.214 +} 1.215 + 1.216 + 1.217 +void FpuStackAllocator::compute_debug_information(LIR_Op* op) { 1.218 + if (!_debug_information_computed && op->id() != -1 && allocator()->has_info(op->id())) { 1.219 + visitor.visit(op); 1.220 + 1.221 + // exception handling 1.222 + if (allocator()->compilation()->has_exception_handlers()) { 1.223 + XHandlers* xhandlers = visitor.all_xhandler(); 1.224 + int n = xhandlers->length(); 1.225 + for (int k = 0; k < n; k++) { 1.226 + allocate_exception_handler(xhandlers->handler_at(k)); 1.227 + } 1.228 + } else { 1.229 + assert(visitor.all_xhandler()->length() == 0, "missed exception handler"); 1.230 + } 1.231 + 1.232 + // compute debug information 1.233 + int n = visitor.info_count(); 1.234 + assert(n > 0, "should not visit operation otherwise"); 1.235 + 1.236 + for (int j = 0; j < n; j++) { 1.237 + CodeEmitInfo* info = visitor.info_at(j); 1.238 + // Compute debug information 1.239 + allocator()->compute_debug_info(info, op->id()); 1.240 + } 1.241 + } 1.242 + _debug_information_computed = true; 1.243 +} 1.244 + 1.245 +void FpuStackAllocator::allocate_exception_handler(XHandler* xhandler) { 1.246 + if (!sim()->is_empty()) { 1.247 + LIR_List* old_lir = lir(); 1.248 + int old_pos = pos(); 1.249 + intArray* old_state = sim()->write_state(); 1.250 + 1.251 +#ifndef PRODUCT 1.252 + if (TraceFPUStack) { 1.253 + tty->cr(); 1.254 + tty->print_cr("------- begin of exception handler -------"); 1.255 + } 1.256 +#endif 1.257 + 1.258 + if (xhandler->entry_code() == NULL) { 1.259 + // need entry code to clear FPU stack 1.260 + LIR_List* entry_code = new LIR_List(_compilation); 1.261 + entry_code->jump(xhandler->entry_block()); 1.262 + xhandler->set_entry_code(entry_code); 1.263 + } 1.264 + 1.265 + LIR_OpList* insts = xhandler->entry_code()->instructions_list(); 1.266 + set_lir(xhandler->entry_code()); 1.267 + set_pos(0); 1.268 + 1.269 + // Note: insts->length() may change during loop 1.270 + while (pos() < insts->length()) { 1.271 + LIR_Op* op = insts->at(pos()); 1.272 + 1.273 +#ifndef PRODUCT 1.274 + if (TraceFPUStack) { 1.275 + op->print(); 1.276 + } 1.277 + check_invalid_lir_op(op); 1.278 +#endif 1.279 + 1.280 + switch (op->code()) { 1.281 + case lir_move: 1.282 + assert(op->as_Op1() != NULL, "must be LIR_Op1"); 1.283 + assert(pos() != insts->length() - 1, "must not be last operation"); 1.284 + 1.285 + handle_op1((LIR_Op1*)op); 1.286 + break; 1.287 + 1.288 + case lir_branch: 1.289 + assert(op->as_OpBranch()->cond() == lir_cond_always, "must be unconditional branch"); 1.290 + assert(pos() == insts->length() - 1, "must be last operation"); 1.291 + 1.292 + // remove all remaining dead registers from FPU stack 1.293 + clear_fpu_stack(LIR_OprFact::illegalOpr); 1.294 + break; 1.295 + 1.296 + default: 1.297 + // other operations not allowed in exception entry code 1.298 + ShouldNotReachHere(); 1.299 + } 1.300 + 1.301 + set_pos(pos() + 1); 1.302 + } 1.303 + 1.304 +#ifndef PRODUCT 1.305 + if (TraceFPUStack) { 1.306 + tty->cr(); 1.307 + tty->print_cr("------- end of exception handler -------"); 1.308 + } 1.309 +#endif 1.310 + 1.311 + set_lir(old_lir); 1.312 + set_pos(old_pos); 1.313 + sim()->read_state(old_state); 1.314 + } 1.315 +} 1.316 + 1.317 + 1.318 +int FpuStackAllocator::fpu_num(LIR_Opr opr) { 1.319 + assert(opr->is_fpu_register() && !opr->is_xmm_register(), "shouldn't call this otherwise"); 1.320 + return opr->is_single_fpu() ? opr->fpu_regnr() : opr->fpu_regnrLo(); 1.321 +} 1.322 + 1.323 +int FpuStackAllocator::tos_offset(LIR_Opr opr) { 1.324 + return sim()->offset_from_tos(fpu_num(opr)); 1.325 +} 1.326 + 1.327 + 1.328 +LIR_Opr FpuStackAllocator::to_fpu_stack(LIR_Opr opr) { 1.329 + assert(opr->is_fpu_register() && !opr->is_xmm_register(), "shouldn't call this otherwise"); 1.330 + 1.331 + int stack_offset = tos_offset(opr); 1.332 + if (opr->is_single_fpu()) { 1.333 + return LIR_OprFact::single_fpu(stack_offset)->make_fpu_stack_offset(); 1.334 + } else { 1.335 + assert(opr->is_double_fpu(), "shouldn't call this otherwise"); 1.336 + return LIR_OprFact::double_fpu(stack_offset)->make_fpu_stack_offset(); 1.337 + } 1.338 +} 1.339 + 1.340 +LIR_Opr FpuStackAllocator::to_fpu_stack_top(LIR_Opr opr, bool dont_check_offset) { 1.341 + assert(opr->is_fpu_register() && !opr->is_xmm_register(), "shouldn't call this otherwise"); 1.342 + assert(dont_check_offset || tos_offset(opr) == 0, "operand is not on stack top"); 1.343 + 1.344 + int stack_offset = 0; 1.345 + if (opr->is_single_fpu()) { 1.346 + return LIR_OprFact::single_fpu(stack_offset)->make_fpu_stack_offset(); 1.347 + } else { 1.348 + assert(opr->is_double_fpu(), "shouldn't call this otherwise"); 1.349 + return LIR_OprFact::double_fpu(stack_offset)->make_fpu_stack_offset(); 1.350 + } 1.351 +} 1.352 + 1.353 + 1.354 + 1.355 +void FpuStackAllocator::insert_op(LIR_Op* op) { 1.356 + lir()->insert_before(pos(), op); 1.357 + set_pos(1 + pos()); 1.358 +} 1.359 + 1.360 + 1.361 +void FpuStackAllocator::insert_exchange(int offset) { 1.362 + if (offset > 0) { 1.363 + LIR_Op1* fxch_op = new LIR_Op1(lir_fxch, LIR_OprFact::intConst(offset), LIR_OprFact::illegalOpr); 1.364 + insert_op(fxch_op); 1.365 + sim()->swap(offset); 1.366 + 1.367 +#ifndef PRODUCT 1.368 + if (TraceFPUStack) { 1.369 + tty->print("Exchanged register: %d New state: ", sim()->get_slot(0)); sim()->print(); tty->cr(); 1.370 + } 1.371 +#endif 1.372 + 1.373 + } 1.374 +} 1.375 + 1.376 +void FpuStackAllocator::insert_exchange(LIR_Opr opr) { 1.377 + insert_exchange(tos_offset(opr)); 1.378 +} 1.379 + 1.380 + 1.381 +void FpuStackAllocator::insert_free(int offset) { 1.382 + // move stack slot to the top of stack and then pop it 1.383 + insert_exchange(offset); 1.384 + 1.385 + LIR_Op* fpop = new LIR_Op0(lir_fpop_raw); 1.386 + insert_op(fpop); 1.387 + sim()->pop(); 1.388 + 1.389 +#ifndef PRODUCT 1.390 + if (TraceFPUStack) { 1.391 + tty->print("Inserted pop New state: "); sim()->print(); tty->cr(); 1.392 + } 1.393 +#endif 1.394 +} 1.395 + 1.396 + 1.397 +void FpuStackAllocator::insert_free_if_dead(LIR_Opr opr) { 1.398 + if (sim()->contains(fpu_num(opr))) { 1.399 + int res_slot = tos_offset(opr); 1.400 + insert_free(res_slot); 1.401 + } 1.402 +} 1.403 + 1.404 +void FpuStackAllocator::insert_free_if_dead(LIR_Opr opr, LIR_Opr ignore) { 1.405 + if (fpu_num(opr) != fpu_num(ignore) && sim()->contains(fpu_num(opr))) { 1.406 + int res_slot = tos_offset(opr); 1.407 + insert_free(res_slot); 1.408 + } 1.409 +} 1.410 + 1.411 +void FpuStackAllocator::insert_copy(LIR_Opr from, LIR_Opr to) { 1.412 + int offset = tos_offset(from); 1.413 + LIR_Op1* fld = new LIR_Op1(lir_fld, LIR_OprFact::intConst(offset), LIR_OprFact::illegalOpr); 1.414 + insert_op(fld); 1.415 + 1.416 + sim()->push(fpu_num(to)); 1.417 + 1.418 +#ifndef PRODUCT 1.419 + if (TraceFPUStack) { 1.420 + tty->print("Inserted copy (%d -> %d) New state: ", fpu_num(from), fpu_num(to)); sim()->print(); tty->cr(); 1.421 + } 1.422 +#endif 1.423 +} 1.424 + 1.425 +void FpuStackAllocator::do_rename(LIR_Opr from, LIR_Opr to) { 1.426 + sim()->rename(fpu_num(from), fpu_num(to)); 1.427 +} 1.428 + 1.429 +void FpuStackAllocator::do_push(LIR_Opr opr) { 1.430 + sim()->push(fpu_num(opr)); 1.431 +} 1.432 + 1.433 +void FpuStackAllocator::pop_if_last_use(LIR_Op* op, LIR_Opr opr) { 1.434 + assert(op->fpu_pop_count() == 0, "fpu_pop_count alredy set"); 1.435 + assert(tos_offset(opr) == 0, "can only pop stack top"); 1.436 + 1.437 + if (opr->is_last_use()) { 1.438 + op->set_fpu_pop_count(1); 1.439 + sim()->pop(); 1.440 + } 1.441 +} 1.442 + 1.443 +void FpuStackAllocator::pop_always(LIR_Op* op, LIR_Opr opr) { 1.444 + assert(op->fpu_pop_count() == 0, "fpu_pop_count alredy set"); 1.445 + assert(tos_offset(opr) == 0, "can only pop stack top"); 1.446 + 1.447 + op->set_fpu_pop_count(1); 1.448 + sim()->pop(); 1.449 +} 1.450 + 1.451 +void FpuStackAllocator::clear_fpu_stack(LIR_Opr preserve) { 1.452 + int result_stack_size = (preserve->is_fpu_register() && !preserve->is_xmm_register() ? 1 : 0); 1.453 + while (sim()->stack_size() > result_stack_size) { 1.454 + assert(!sim()->slot_is_empty(0), "not allowed"); 1.455 + 1.456 + if (result_stack_size == 0 || sim()->get_slot(0) != fpu_num(preserve)) { 1.457 + insert_free(0); 1.458 + } else { 1.459 + // move "preserve" to bottom of stack so that all other stack slots can be popped 1.460 + insert_exchange(sim()->stack_size() - 1); 1.461 + } 1.462 + } 1.463 +} 1.464 + 1.465 + 1.466 +void FpuStackAllocator::handle_op1(LIR_Op1* op1) { 1.467 + LIR_Opr in = op1->in_opr(); 1.468 + LIR_Opr res = op1->result_opr(); 1.469 + 1.470 + LIR_Opr new_in = in; // new operands relative to the actual fpu stack top 1.471 + LIR_Opr new_res = res; 1.472 + 1.473 + // Note: this switch is processed for all LIR_Op1, regardless if they have FPU-arguments, 1.474 + // so checks for is_float_kind() are necessary inside the cases 1.475 + switch (op1->code()) { 1.476 + 1.477 + case lir_return: { 1.478 + // FPU-Stack must only contain the (optional) fpu return value. 1.479 + // All remaining dead values are popped from the stack 1.480 + // If the input operand is a fpu-register, it is exchanged to the bottom of the stack 1.481 + 1.482 + clear_fpu_stack(in); 1.483 + if (in->is_fpu_register() && !in->is_xmm_register()) { 1.484 + new_in = to_fpu_stack_top(in); 1.485 + } 1.486 + 1.487 + break; 1.488 + } 1.489 + 1.490 + case lir_move: { 1.491 + if (in->is_fpu_register() && !in->is_xmm_register()) { 1.492 + if (res->is_xmm_register()) { 1.493 + // move from fpu register to xmm register (necessary for operations that 1.494 + // are not available in the SSE instruction set) 1.495 + insert_exchange(in); 1.496 + new_in = to_fpu_stack_top(in); 1.497 + pop_always(op1, in); 1.498 + 1.499 + } else if (res->is_fpu_register() && !res->is_xmm_register()) { 1.500 + // move from fpu-register to fpu-register: 1.501 + // * input and result register equal: 1.502 + // nothing to do 1.503 + // * input register is last use: 1.504 + // rename the input register to result register -> input register 1.505 + // not present on fpu-stack afterwards 1.506 + // * input register not last use: 1.507 + // duplicate input register to result register to preserve input 1.508 + // 1.509 + // Note: The LIR-Assembler does not produce any code for fpu register moves, 1.510 + // so input and result stack index must be equal 1.511 + 1.512 + if (fpu_num(in) == fpu_num(res)) { 1.513 + // nothing to do 1.514 + } else if (in->is_last_use()) { 1.515 + insert_free_if_dead(res);//, in); 1.516 + do_rename(in, res); 1.517 + } else { 1.518 + insert_free_if_dead(res); 1.519 + insert_copy(in, res); 1.520 + } 1.521 + new_in = to_fpu_stack(res); 1.522 + new_res = new_in; 1.523 + 1.524 + } else { 1.525 + // move from fpu-register to memory 1.526 + // input operand must be on top of stack 1.527 + 1.528 + insert_exchange(in); 1.529 + 1.530 + // create debug information here because afterwards the register may have been popped 1.531 + compute_debug_information(op1); 1.532 + 1.533 + new_in = to_fpu_stack_top(in); 1.534 + pop_if_last_use(op1, in); 1.535 + } 1.536 + 1.537 + } else if (res->is_fpu_register() && !res->is_xmm_register()) { 1.538 + // move from memory/constant to fpu register 1.539 + // result is pushed on the stack 1.540 + 1.541 + insert_free_if_dead(res); 1.542 + 1.543 + // create debug information before register is pushed 1.544 + compute_debug_information(op1); 1.545 + 1.546 + do_push(res); 1.547 + new_res = to_fpu_stack_top(res); 1.548 + } 1.549 + break; 1.550 + } 1.551 + 1.552 + case lir_neg: { 1.553 + if (in->is_fpu_register() && !in->is_xmm_register()) { 1.554 + assert(res->is_fpu_register() && !res->is_xmm_register(), "must be"); 1.555 + assert(in->is_last_use(), "old value gets destroyed"); 1.556 + 1.557 + insert_free_if_dead(res, in); 1.558 + insert_exchange(in); 1.559 + new_in = to_fpu_stack_top(in); 1.560 + 1.561 + do_rename(in, res); 1.562 + new_res = to_fpu_stack_top(res); 1.563 + } 1.564 + break; 1.565 + } 1.566 + 1.567 + case lir_convert: { 1.568 + Bytecodes::Code bc = op1->as_OpConvert()->bytecode(); 1.569 + switch (bc) { 1.570 + case Bytecodes::_d2f: 1.571 + case Bytecodes::_f2d: 1.572 + assert(res->is_fpu_register(), "must be"); 1.573 + assert(in->is_fpu_register(), "must be"); 1.574 + 1.575 + if (!in->is_xmm_register() && !res->is_xmm_register()) { 1.576 + // this is quite the same as a move from fpu-register to fpu-register 1.577 + // Note: input and result operands must have different types 1.578 + if (fpu_num(in) == fpu_num(res)) { 1.579 + // nothing to do 1.580 + new_in = to_fpu_stack(in); 1.581 + } else if (in->is_last_use()) { 1.582 + insert_free_if_dead(res);//, in); 1.583 + new_in = to_fpu_stack(in); 1.584 + do_rename(in, res); 1.585 + } else { 1.586 + insert_free_if_dead(res); 1.587 + insert_copy(in, res); 1.588 + new_in = to_fpu_stack_top(in, true); 1.589 + } 1.590 + new_res = to_fpu_stack(res); 1.591 + } 1.592 + 1.593 + break; 1.594 + 1.595 + case Bytecodes::_i2f: 1.596 + case Bytecodes::_l2f: 1.597 + case Bytecodes::_i2d: 1.598 + case Bytecodes::_l2d: 1.599 + assert(res->is_fpu_register(), "must be"); 1.600 + if (!res->is_xmm_register()) { 1.601 + insert_free_if_dead(res); 1.602 + do_push(res); 1.603 + new_res = to_fpu_stack_top(res); 1.604 + } 1.605 + break; 1.606 + 1.607 + case Bytecodes::_f2i: 1.608 + case Bytecodes::_d2i: 1.609 + assert(in->is_fpu_register(), "must be"); 1.610 + if (!in->is_xmm_register()) { 1.611 + insert_exchange(in); 1.612 + new_in = to_fpu_stack_top(in); 1.613 + 1.614 + // TODO: update registes of stub 1.615 + } 1.616 + break; 1.617 + 1.618 + case Bytecodes::_f2l: 1.619 + case Bytecodes::_d2l: 1.620 + assert(in->is_fpu_register(), "must be"); 1.621 + if (!in->is_xmm_register()) { 1.622 + insert_exchange(in); 1.623 + new_in = to_fpu_stack_top(in); 1.624 + pop_always(op1, in); 1.625 + } 1.626 + break; 1.627 + 1.628 + case Bytecodes::_i2l: 1.629 + case Bytecodes::_l2i: 1.630 + case Bytecodes::_i2b: 1.631 + case Bytecodes::_i2c: 1.632 + case Bytecodes::_i2s: 1.633 + // no fpu operands 1.634 + break; 1.635 + 1.636 + default: 1.637 + ShouldNotReachHere(); 1.638 + } 1.639 + break; 1.640 + } 1.641 + 1.642 + case lir_roundfp: { 1.643 + assert(in->is_fpu_register() && !in->is_xmm_register(), "input must be in register"); 1.644 + assert(res->is_stack(), "result must be on stack"); 1.645 + 1.646 + insert_exchange(in); 1.647 + new_in = to_fpu_stack_top(in); 1.648 + pop_if_last_use(op1, in); 1.649 + break; 1.650 + } 1.651 + 1.652 + default: { 1.653 + assert(!in->is_float_kind() && !res->is_float_kind(), "missed a fpu-operation"); 1.654 + } 1.655 + } 1.656 + 1.657 + op1->set_in_opr(new_in); 1.658 + op1->set_result_opr(new_res); 1.659 +} 1.660 + 1.661 +void FpuStackAllocator::handle_op2(LIR_Op2* op2) { 1.662 + LIR_Opr left = op2->in_opr1(); 1.663 + if (!left->is_float_kind()) { 1.664 + return; 1.665 + } 1.666 + if (left->is_xmm_register()) { 1.667 + return; 1.668 + } 1.669 + 1.670 + LIR_Opr right = op2->in_opr2(); 1.671 + LIR_Opr res = op2->result_opr(); 1.672 + LIR_Opr new_left = left; // new operands relative to the actual fpu stack top 1.673 + LIR_Opr new_right = right; 1.674 + LIR_Opr new_res = res; 1.675 + 1.676 + assert(!left->is_xmm_register() && !right->is_xmm_register() && !res->is_xmm_register(), "not for xmm registers"); 1.677 + 1.678 + switch (op2->code()) { 1.679 + case lir_cmp: 1.680 + case lir_cmp_fd2i: 1.681 + case lir_ucmp_fd2i: 1.682 + case lir_assert: { 1.683 + assert(left->is_fpu_register(), "invalid LIR"); 1.684 + assert(right->is_fpu_register(), "invalid LIR"); 1.685 + 1.686 + // the left-hand side must be on top of stack. 1.687 + // the right-hand side is never popped, even if is_last_use is set 1.688 + insert_exchange(left); 1.689 + new_left = to_fpu_stack_top(left); 1.690 + new_right = to_fpu_stack(right); 1.691 + pop_if_last_use(op2, left); 1.692 + break; 1.693 + } 1.694 + 1.695 + case lir_mul_strictfp: 1.696 + case lir_div_strictfp: { 1.697 + assert(op2->tmp1_opr()->is_fpu_register(), "strict operations need temporary fpu stack slot"); 1.698 + insert_free_if_dead(op2->tmp1_opr()); 1.699 + assert(sim()->stack_size() <= 7, "at least one stack slot must be free"); 1.700 + // fall-through: continue with the normal handling of lir_mul and lir_div 1.701 + } 1.702 + case lir_add: 1.703 + case lir_sub: 1.704 + case lir_mul: 1.705 + case lir_div: { 1.706 + assert(left->is_fpu_register(), "must be"); 1.707 + assert(res->is_fpu_register(), "must be"); 1.708 + assert(left->is_equal(res), "must be"); 1.709 + 1.710 + // either the left-hand or the right-hand side must be on top of stack 1.711 + // (if right is not a register, left must be on top) 1.712 + if (!right->is_fpu_register()) { 1.713 + insert_exchange(left); 1.714 + new_left = to_fpu_stack_top(left); 1.715 + } else { 1.716 + // no exchange necessary if right is alredy on top of stack 1.717 + if (tos_offset(right) == 0) { 1.718 + new_left = to_fpu_stack(left); 1.719 + new_right = to_fpu_stack_top(right); 1.720 + } else { 1.721 + insert_exchange(left); 1.722 + new_left = to_fpu_stack_top(left); 1.723 + new_right = to_fpu_stack(right); 1.724 + } 1.725 + 1.726 + if (right->is_last_use()) { 1.727 + op2->set_fpu_pop_count(1); 1.728 + 1.729 + if (tos_offset(right) == 0) { 1.730 + sim()->pop(); 1.731 + } else { 1.732 + // if left is on top of stack, the result is placed in the stack 1.733 + // slot of right, so a renaming from right to res is necessary 1.734 + assert(tos_offset(left) == 0, "must be"); 1.735 + sim()->pop(); 1.736 + do_rename(right, res); 1.737 + } 1.738 + } 1.739 + } 1.740 + new_res = to_fpu_stack(res); 1.741 + 1.742 + break; 1.743 + } 1.744 + 1.745 + case lir_rem: { 1.746 + assert(left->is_fpu_register(), "must be"); 1.747 + assert(right->is_fpu_register(), "must be"); 1.748 + assert(res->is_fpu_register(), "must be"); 1.749 + assert(left->is_equal(res), "must be"); 1.750 + 1.751 + // Must bring both operands to top of stack with following operand ordering: 1.752 + // * fpu stack before rem: ... right left 1.753 + // * fpu stack after rem: ... left 1.754 + if (tos_offset(right) != 1) { 1.755 + insert_exchange(right); 1.756 + insert_exchange(1); 1.757 + } 1.758 + insert_exchange(left); 1.759 + assert(tos_offset(right) == 1, "check"); 1.760 + assert(tos_offset(left) == 0, "check"); 1.761 + 1.762 + new_left = to_fpu_stack_top(left); 1.763 + new_right = to_fpu_stack(right); 1.764 + 1.765 + op2->set_fpu_pop_count(1); 1.766 + sim()->pop(); 1.767 + do_rename(right, res); 1.768 + 1.769 + new_res = to_fpu_stack_top(res); 1.770 + break; 1.771 + } 1.772 + 1.773 + case lir_abs: 1.774 + case lir_sqrt: { 1.775 + // Right argument appears to be unused 1.776 + assert(right->is_illegal(), "must be"); 1.777 + assert(left->is_fpu_register(), "must be"); 1.778 + assert(res->is_fpu_register(), "must be"); 1.779 + assert(left->is_last_use(), "old value gets destroyed"); 1.780 + 1.781 + insert_free_if_dead(res, left); 1.782 + insert_exchange(left); 1.783 + do_rename(left, res); 1.784 + 1.785 + new_left = to_fpu_stack_top(res); 1.786 + new_res = new_left; 1.787 + 1.788 + op2->set_fpu_stack_size(sim()->stack_size()); 1.789 + break; 1.790 + } 1.791 + 1.792 + case lir_log: 1.793 + case lir_log10: { 1.794 + // log and log10 need one temporary fpu stack slot, so 1.795 + // there is one temporary registers stored in temp of the 1.796 + // operation. the stack allocator must guarantee that the stack 1.797 + // slots are really free, otherwise there might be a stack 1.798 + // overflow. 1.799 + assert(right->is_illegal(), "must be"); 1.800 + assert(left->is_fpu_register(), "must be"); 1.801 + assert(res->is_fpu_register(), "must be"); 1.802 + assert(op2->tmp1_opr()->is_fpu_register(), "must be"); 1.803 + 1.804 + insert_free_if_dead(op2->tmp1_opr()); 1.805 + insert_free_if_dead(res, left); 1.806 + insert_exchange(left); 1.807 + do_rename(left, res); 1.808 + 1.809 + new_left = to_fpu_stack_top(res); 1.810 + new_res = new_left; 1.811 + 1.812 + op2->set_fpu_stack_size(sim()->stack_size()); 1.813 + assert(sim()->stack_size() <= 7, "at least one stack slot must be free"); 1.814 + break; 1.815 + } 1.816 + 1.817 + 1.818 + case lir_tan: 1.819 + case lir_sin: 1.820 + case lir_cos: 1.821 + case lir_exp: { 1.822 + // sin, cos and exp need two temporary fpu stack slots, so there are two temporary 1.823 + // registers (stored in right and temp of the operation). 1.824 + // the stack allocator must guarantee that the stack slots are really free, 1.825 + // otherwise there might be a stack overflow. 1.826 + assert(left->is_fpu_register(), "must be"); 1.827 + assert(res->is_fpu_register(), "must be"); 1.828 + // assert(left->is_last_use(), "old value gets destroyed"); 1.829 + assert(right->is_fpu_register(), "right is used as the first temporary register"); 1.830 + assert(op2->tmp1_opr()->is_fpu_register(), "temp is used as the second temporary register"); 1.831 + assert(fpu_num(left) != fpu_num(right) && fpu_num(right) != fpu_num(op2->tmp1_opr()) && fpu_num(op2->tmp1_opr()) != fpu_num(res), "need distinct temp registers"); 1.832 + 1.833 + insert_free_if_dead(right); 1.834 + insert_free_if_dead(op2->tmp1_opr()); 1.835 + 1.836 + insert_free_if_dead(res, left); 1.837 + insert_exchange(left); 1.838 + do_rename(left, res); 1.839 + 1.840 + new_left = to_fpu_stack_top(res); 1.841 + new_res = new_left; 1.842 + 1.843 + op2->set_fpu_stack_size(sim()->stack_size()); 1.844 + assert(sim()->stack_size() <= 6, "at least two stack slots must be free"); 1.845 + break; 1.846 + } 1.847 + 1.848 + case lir_pow: { 1.849 + // pow needs two temporary fpu stack slots, so there are two temporary 1.850 + // registers (stored in tmp1 and tmp2 of the operation). 1.851 + // the stack allocator must guarantee that the stack slots are really free, 1.852 + // otherwise there might be a stack overflow. 1.853 + assert(left->is_fpu_register(), "must be"); 1.854 + assert(right->is_fpu_register(), "must be"); 1.855 + assert(res->is_fpu_register(), "must be"); 1.856 + 1.857 + assert(op2->tmp1_opr()->is_fpu_register(), "tmp1 is the first temporary register"); 1.858 + assert(op2->tmp2_opr()->is_fpu_register(), "tmp2 is the second temporary register"); 1.859 + assert(fpu_num(left) != fpu_num(right) && fpu_num(left) != fpu_num(op2->tmp1_opr()) && fpu_num(left) != fpu_num(op2->tmp2_opr()) && fpu_num(left) != fpu_num(res), "need distinct temp registers"); 1.860 + assert(fpu_num(right) != fpu_num(op2->tmp1_opr()) && fpu_num(right) != fpu_num(op2->tmp2_opr()) && fpu_num(right) != fpu_num(res), "need distinct temp registers"); 1.861 + assert(fpu_num(op2->tmp1_opr()) != fpu_num(op2->tmp2_opr()) && fpu_num(op2->tmp1_opr()) != fpu_num(res), "need distinct temp registers"); 1.862 + assert(fpu_num(op2->tmp2_opr()) != fpu_num(res), "need distinct temp registers"); 1.863 + 1.864 + insert_free_if_dead(op2->tmp1_opr()); 1.865 + insert_free_if_dead(op2->tmp2_opr()); 1.866 + 1.867 + // Must bring both operands to top of stack with following operand ordering: 1.868 + // * fpu stack before pow: ... right left 1.869 + // * fpu stack after pow: ... left 1.870 + 1.871 + insert_free_if_dead(res, right); 1.872 + 1.873 + if (tos_offset(right) != 1) { 1.874 + insert_exchange(right); 1.875 + insert_exchange(1); 1.876 + } 1.877 + insert_exchange(left); 1.878 + assert(tos_offset(right) == 1, "check"); 1.879 + assert(tos_offset(left) == 0, "check"); 1.880 + 1.881 + new_left = to_fpu_stack_top(left); 1.882 + new_right = to_fpu_stack(right); 1.883 + 1.884 + op2->set_fpu_stack_size(sim()->stack_size()); 1.885 + assert(sim()->stack_size() <= 6, "at least two stack slots must be free"); 1.886 + 1.887 + sim()->pop(); 1.888 + 1.889 + do_rename(right, res); 1.890 + 1.891 + new_res = to_fpu_stack_top(res); 1.892 + break; 1.893 + } 1.894 + 1.895 + default: { 1.896 + assert(false, "missed a fpu-operation"); 1.897 + } 1.898 + } 1.899 + 1.900 + op2->set_in_opr1(new_left); 1.901 + op2->set_in_opr2(new_right); 1.902 + op2->set_result_opr(new_res); 1.903 +} 1.904 + 1.905 +void FpuStackAllocator::handle_opCall(LIR_OpCall* opCall) { 1.906 + LIR_Opr res = opCall->result_opr(); 1.907 + 1.908 + // clear fpu-stack before call 1.909 + // it may contain dead values that could not have been remved by previous operations 1.910 + clear_fpu_stack(LIR_OprFact::illegalOpr); 1.911 + assert(sim()->is_empty(), "fpu stack must be empty now"); 1.912 + 1.913 + // compute debug information before (possible) fpu result is pushed 1.914 + compute_debug_information(opCall); 1.915 + 1.916 + if (res->is_fpu_register() && !res->is_xmm_register()) { 1.917 + do_push(res); 1.918 + opCall->set_result_opr(to_fpu_stack_top(res)); 1.919 + } 1.920 +} 1.921 + 1.922 +#ifndef PRODUCT 1.923 +void FpuStackAllocator::check_invalid_lir_op(LIR_Op* op) { 1.924 + switch (op->code()) { 1.925 + case lir_24bit_FPU: 1.926 + case lir_reset_FPU: 1.927 + case lir_ffree: 1.928 + assert(false, "operations not allowed in lir. If one of these operations is needed, check if they have fpu operands"); 1.929 + break; 1.930 + 1.931 + case lir_fpop_raw: 1.932 + case lir_fxch: 1.933 + case lir_fld: 1.934 + assert(false, "operations only inserted by FpuStackAllocator"); 1.935 + break; 1.936 + } 1.937 +} 1.938 +#endif 1.939 + 1.940 + 1.941 +void FpuStackAllocator::merge_insert_add(LIR_List* instrs, FpuStackSim* cur_sim, int reg) { 1.942 + LIR_Op1* move = new LIR_Op1(lir_move, LIR_OprFact::doubleConst(0), LIR_OprFact::double_fpu(reg)->make_fpu_stack_offset()); 1.943 + 1.944 + instrs->instructions_list()->push(move); 1.945 + 1.946 + cur_sim->push(reg); 1.947 + move->set_result_opr(to_fpu_stack(move->result_opr())); 1.948 + 1.949 + #ifndef PRODUCT 1.950 + if (TraceFPUStack) { 1.951 + tty->print("Added new register: %d New state: ", reg); cur_sim->print(); tty->cr(); 1.952 + } 1.953 + #endif 1.954 +} 1.955 + 1.956 +void FpuStackAllocator::merge_insert_xchg(LIR_List* instrs, FpuStackSim* cur_sim, int slot) { 1.957 + assert(slot > 0, "no exchange necessary"); 1.958 + 1.959 + LIR_Op1* fxch = new LIR_Op1(lir_fxch, LIR_OprFact::intConst(slot)); 1.960 + instrs->instructions_list()->push(fxch); 1.961 + cur_sim->swap(slot); 1.962 + 1.963 + #ifndef PRODUCT 1.964 + if (TraceFPUStack) { 1.965 + tty->print("Exchanged register: %d New state: ", cur_sim->get_slot(slot)); cur_sim->print(); tty->cr(); 1.966 + } 1.967 + #endif 1.968 +} 1.969 + 1.970 +void FpuStackAllocator::merge_insert_pop(LIR_List* instrs, FpuStackSim* cur_sim) { 1.971 + int reg = cur_sim->get_slot(0); 1.972 + 1.973 + LIR_Op* fpop = new LIR_Op0(lir_fpop_raw); 1.974 + instrs->instructions_list()->push(fpop); 1.975 + cur_sim->pop(reg); 1.976 + 1.977 + #ifndef PRODUCT 1.978 + if (TraceFPUStack) { 1.979 + tty->print("Removed register: %d New state: ", reg); cur_sim->print(); tty->cr(); 1.980 + } 1.981 + #endif 1.982 +} 1.983 + 1.984 +bool FpuStackAllocator::merge_rename(FpuStackSim* cur_sim, FpuStackSim* sux_sim, int start_slot, int change_slot) { 1.985 + int reg = cur_sim->get_slot(change_slot); 1.986 + 1.987 + for (int slot = start_slot; slot >= 0; slot--) { 1.988 + int new_reg = sux_sim->get_slot(slot); 1.989 + 1.990 + if (!cur_sim->contains(new_reg)) { 1.991 + cur_sim->set_slot(change_slot, new_reg); 1.992 + 1.993 + #ifndef PRODUCT 1.994 + if (TraceFPUStack) { 1.995 + tty->print("Renamed register %d to %d New state: ", reg, new_reg); cur_sim->print(); tty->cr(); 1.996 + } 1.997 + #endif 1.998 + 1.999 + return true; 1.1000 + } 1.1001 + } 1.1002 + return false; 1.1003 +} 1.1004 + 1.1005 + 1.1006 +void FpuStackAllocator::merge_fpu_stack(LIR_List* instrs, FpuStackSim* cur_sim, FpuStackSim* sux_sim) { 1.1007 +#ifndef PRODUCT 1.1008 + if (TraceFPUStack) { 1.1009 + tty->cr(); 1.1010 + tty->print("before merging: pred: "); cur_sim->print(); tty->cr(); 1.1011 + tty->print(" sux: "); sux_sim->print(); tty->cr(); 1.1012 + } 1.1013 + 1.1014 + int slot; 1.1015 + for (slot = 0; slot < cur_sim->stack_size(); slot++) { 1.1016 + assert(!cur_sim->slot_is_empty(slot), "not handled by algorithm"); 1.1017 + } 1.1018 + for (slot = 0; slot < sux_sim->stack_size(); slot++) { 1.1019 + assert(!sux_sim->slot_is_empty(slot), "not handled by algorithm"); 1.1020 + } 1.1021 +#endif 1.1022 + 1.1023 + // size difference between cur and sux that must be resolved by adding or removing values form the stack 1.1024 + int size_diff = cur_sim->stack_size() - sux_sim->stack_size(); 1.1025 + 1.1026 + if (!ComputeExactFPURegisterUsage) { 1.1027 + // add slots that are currently free, but used in successor 1.1028 + // When the exact FPU register usage is computed, the stack does 1.1029 + // not contain dead values at merging -> no values must be added 1.1030 + 1.1031 + int sux_slot = sux_sim->stack_size() - 1; 1.1032 + while (size_diff < 0) { 1.1033 + assert(sux_slot >= 0, "slot out of bounds -> error in algorithm"); 1.1034 + 1.1035 + int reg = sux_sim->get_slot(sux_slot); 1.1036 + if (!cur_sim->contains(reg)) { 1.1037 + merge_insert_add(instrs, cur_sim, reg); 1.1038 + size_diff++; 1.1039 + 1.1040 + if (sux_slot + size_diff != 0) { 1.1041 + merge_insert_xchg(instrs, cur_sim, sux_slot + size_diff); 1.1042 + } 1.1043 + } 1.1044 + sux_slot--; 1.1045 + } 1.1046 + } 1.1047 + 1.1048 + assert(cur_sim->stack_size() >= sux_sim->stack_size(), "stack size must be equal or greater now"); 1.1049 + assert(size_diff == cur_sim->stack_size() - sux_sim->stack_size(), "must be"); 1.1050 + 1.1051 + // stack merge algorithm: 1.1052 + // 1) as long as the current stack top is not in the right location (that meens 1.1053 + // it should not be on the stack top), exchange it into the right location 1.1054 + // 2) if the stack top is right, but the remaining stack is not ordered correctly, 1.1055 + // the stack top is exchanged away to get another value on top -> 1.1056 + // now step 1) can be continued 1.1057 + // the stack can also contain unused items -> these items are removed from stack 1.1058 + 1.1059 + int finished_slot = sux_sim->stack_size() - 1; 1.1060 + while (finished_slot >= 0 || size_diff > 0) { 1.1061 + while (size_diff > 0 || (cur_sim->stack_size() > 0 && cur_sim->get_slot(0) != sux_sim->get_slot(0))) { 1.1062 + int reg = cur_sim->get_slot(0); 1.1063 + if (sux_sim->contains(reg)) { 1.1064 + int sux_slot = sux_sim->offset_from_tos(reg); 1.1065 + merge_insert_xchg(instrs, cur_sim, sux_slot + size_diff); 1.1066 + 1.1067 + } else if (!merge_rename(cur_sim, sux_sim, finished_slot, 0)) { 1.1068 + assert(size_diff > 0, "must be"); 1.1069 + 1.1070 + merge_insert_pop(instrs, cur_sim); 1.1071 + size_diff--; 1.1072 + } 1.1073 + assert(cur_sim->stack_size() == 0 || cur_sim->get_slot(0) != reg, "register must have been changed"); 1.1074 + } 1.1075 + 1.1076 + while (finished_slot >= 0 && cur_sim->get_slot(finished_slot) == sux_sim->get_slot(finished_slot)) { 1.1077 + finished_slot--; 1.1078 + } 1.1079 + 1.1080 + if (finished_slot >= 0) { 1.1081 + int reg = cur_sim->get_slot(finished_slot); 1.1082 + 1.1083 + if (sux_sim->contains(reg) || !merge_rename(cur_sim, sux_sim, finished_slot, finished_slot)) { 1.1084 + assert(sux_sim->contains(reg) || size_diff > 0, "must be"); 1.1085 + merge_insert_xchg(instrs, cur_sim, finished_slot); 1.1086 + } 1.1087 + assert(cur_sim->get_slot(finished_slot) != reg, "register must have been changed"); 1.1088 + } 1.1089 + } 1.1090 + 1.1091 +#ifndef PRODUCT 1.1092 + if (TraceFPUStack) { 1.1093 + tty->print("after merging: pred: "); cur_sim->print(); tty->cr(); 1.1094 + tty->print(" sux: "); sux_sim->print(); tty->cr(); 1.1095 + tty->cr(); 1.1096 + } 1.1097 +#endif 1.1098 + assert(cur_sim->stack_size() == sux_sim->stack_size(), "stack size must be equal now"); 1.1099 +} 1.1100 + 1.1101 + 1.1102 +void FpuStackAllocator::merge_cleanup_fpu_stack(LIR_List* instrs, FpuStackSim* cur_sim, BitMap& live_fpu_regs) { 1.1103 +#ifndef PRODUCT 1.1104 + if (TraceFPUStack) { 1.1105 + tty->cr(); 1.1106 + tty->print("before cleanup: state: "); cur_sim->print(); tty->cr(); 1.1107 + tty->print(" live: "); live_fpu_regs.print_on(tty); tty->cr(); 1.1108 + } 1.1109 +#endif 1.1110 + 1.1111 + int slot = 0; 1.1112 + while (slot < cur_sim->stack_size()) { 1.1113 + int reg = cur_sim->get_slot(slot); 1.1114 + if (!live_fpu_regs.at(reg)) { 1.1115 + if (slot != 0) { 1.1116 + merge_insert_xchg(instrs, cur_sim, slot); 1.1117 + } 1.1118 + merge_insert_pop(instrs, cur_sim); 1.1119 + } else { 1.1120 + slot++; 1.1121 + } 1.1122 + } 1.1123 + 1.1124 +#ifndef PRODUCT 1.1125 + if (TraceFPUStack) { 1.1126 + tty->print("after cleanup: state: "); cur_sim->print(); tty->cr(); 1.1127 + tty->print(" live: "); live_fpu_regs.print_on(tty); tty->cr(); 1.1128 + tty->cr(); 1.1129 + } 1.1130 + 1.1131 + // check if fpu stack only contains live registers 1.1132 + for (unsigned int i = 0; i < live_fpu_regs.size(); i++) { 1.1133 + if (live_fpu_regs.at(i) != cur_sim->contains(i)) { 1.1134 + tty->print_cr("mismatch between required and actual stack content"); 1.1135 + break; 1.1136 + } 1.1137 + } 1.1138 +#endif 1.1139 +} 1.1140 + 1.1141 + 1.1142 +bool FpuStackAllocator::merge_fpu_stack_with_successors(BlockBegin* block) { 1.1143 +#ifndef PRODUCT 1.1144 + if (TraceFPUStack) { 1.1145 + tty->print_cr("Propagating FPU stack state for B%d at LIR_Op position %d to successors:", 1.1146 + block->block_id(), pos()); 1.1147 + sim()->print(); 1.1148 + tty->cr(); 1.1149 + } 1.1150 +#endif 1.1151 + 1.1152 + bool changed = false; 1.1153 + int number_of_sux = block->number_of_sux(); 1.1154 + 1.1155 + if (number_of_sux == 1 && block->sux_at(0)->number_of_preds() > 1) { 1.1156 + // The successor has at least two incoming edges, so a stack merge will be necessary 1.1157 + // If this block is the first predecessor, cleanup the current stack and propagate it 1.1158 + // If this block is not the first predecessor, a stack merge will be necessary 1.1159 + 1.1160 + BlockBegin* sux = block->sux_at(0); 1.1161 + intArray* state = sux->fpu_stack_state(); 1.1162 + LIR_List* instrs = new LIR_List(_compilation); 1.1163 + 1.1164 + if (state != NULL) { 1.1165 + // Merge with a successors that already has a FPU stack state 1.1166 + // the block must only have one successor because critical edges must been split 1.1167 + FpuStackSim* cur_sim = sim(); 1.1168 + FpuStackSim* sux_sim = temp_sim(); 1.1169 + sux_sim->read_state(state); 1.1170 + 1.1171 + merge_fpu_stack(instrs, cur_sim, sux_sim); 1.1172 + 1.1173 + } else { 1.1174 + // propagate current FPU stack state to successor without state 1.1175 + // clean up stack first so that there are no dead values on the stack 1.1176 + if (ComputeExactFPURegisterUsage) { 1.1177 + FpuStackSim* cur_sim = sim(); 1.1178 + BitMap live_fpu_regs = block->sux_at(0)->fpu_register_usage(); 1.1179 + assert(live_fpu_regs.size() == FrameMap::nof_fpu_regs, "missing register usage"); 1.1180 + 1.1181 + merge_cleanup_fpu_stack(instrs, cur_sim, live_fpu_regs); 1.1182 + } 1.1183 + 1.1184 + intArray* state = sim()->write_state(); 1.1185 + if (TraceFPUStack) { 1.1186 + tty->print_cr("Setting FPU stack state of B%d (merge path)", sux->block_id()); 1.1187 + sim()->print(); tty->cr(); 1.1188 + } 1.1189 + sux->set_fpu_stack_state(state); 1.1190 + } 1.1191 + 1.1192 + if (instrs->instructions_list()->length() > 0) { 1.1193 + lir()->insert_before(pos(), instrs); 1.1194 + set_pos(instrs->instructions_list()->length() + pos()); 1.1195 + changed = true; 1.1196 + } 1.1197 + 1.1198 + } else { 1.1199 + // Propagate unmodified Stack to successors where a stack merge is not necessary 1.1200 + intArray* state = sim()->write_state(); 1.1201 + for (int i = 0; i < number_of_sux; i++) { 1.1202 + BlockBegin* sux = block->sux_at(i); 1.1203 + 1.1204 +#ifdef ASSERT 1.1205 + for (int j = 0; j < sux->number_of_preds(); j++) { 1.1206 + assert(block == sux->pred_at(j), "all critical edges must be broken"); 1.1207 + } 1.1208 + 1.1209 + // check if new state is same 1.1210 + if (sux->fpu_stack_state() != NULL) { 1.1211 + intArray* sux_state = sux->fpu_stack_state(); 1.1212 + assert(state->length() == sux_state->length(), "overwriting existing stack state"); 1.1213 + for (int j = 0; j < state->length(); j++) { 1.1214 + assert(state->at(j) == sux_state->at(j), "overwriting existing stack state"); 1.1215 + } 1.1216 + } 1.1217 +#endif 1.1218 +#ifndef PRODUCT 1.1219 + if (TraceFPUStack) { 1.1220 + tty->print_cr("Setting FPU stack state of B%d", sux->block_id()); 1.1221 + sim()->print(); tty->cr(); 1.1222 + } 1.1223 +#endif 1.1224 + 1.1225 + sux->set_fpu_stack_state(state); 1.1226 + } 1.1227 + } 1.1228 + 1.1229 +#ifndef PRODUCT 1.1230 + // assertions that FPU stack state conforms to all successors' states 1.1231 + intArray* cur_state = sim()->write_state(); 1.1232 + for (int i = 0; i < number_of_sux; i++) { 1.1233 + BlockBegin* sux = block->sux_at(i); 1.1234 + intArray* sux_state = sux->fpu_stack_state(); 1.1235 + 1.1236 + assert(sux_state != NULL, "no fpu state"); 1.1237 + assert(cur_state->length() == sux_state->length(), "incorrect length"); 1.1238 + for (int i = 0; i < cur_state->length(); i++) { 1.1239 + assert(cur_state->at(i) == sux_state->at(i), "element not equal"); 1.1240 + } 1.1241 + } 1.1242 +#endif 1.1243 + 1.1244 + return changed; 1.1245 +}