jdk8-mips64-public/hotspot: src/cpu/x86/vm/c1_LinearScan

src/cpu/x86/vm/c1_LinearScan_x86.cpp@18a08a7e16b5 (annotated)

src/cpu/x86/vm/c1_LinearScan_x86.cpp

Fri, 26 Jun 2009 07:26:10 -0700

author: twisti
date: Fri, 26 Jun 2009 07:26:10 -0700
changeset 1259: 18a08a7e16b5
parent 435: a61af66fc99e
child 1388: ff1a29907b6c
permissions: -rw-r--r--

5057225: Remove useless I2L conversions
Summary: The optimizer should be told to normalize (AndL (ConvI2L x) 0xFF) to (ConvI2L (AndI x 0xFF)), and then the existing matcher rule will work for free.
Reviewed-by: kvn

 /*
  * Copyright 2005 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 #include "incls/_precompiled.incl"
 #include "incls/_c1_LinearScan_x86.cpp.incl"
 //----------------------------------------------------------------------
 // Allocation of FPU stack slots (Intel x86 only)
 //----------------------------------------------------------------------
 void LinearScan::allocate_fpu_stack() {
   // First compute which FPU registers are live at the start of each basic block
   // (To minimize the amount of work we have to do if we have to merge FPU stacks)
   if (ComputeExactFPURegisterUsage) {
     Interval* intervals_in_register, *intervals_in_memory;
     create_unhandled_lists(&intervals_in_register, &intervals_in_memory, is_in_fpu_register, NULL);
     // ignore memory intervals by overwriting intervals_in_memory
     // the dummy interval is needed to enforce the walker to walk until the given id:
     // without it, the walker stops when the unhandled-list is empty -> live information
     // beyond this point would be incorrect.
     Interval* dummy_interval = new Interval(any_reg);
     dummy_interval->add_range(max_jint - 2, max_jint - 1);
     dummy_interval->set_next(Interval::end());
     intervals_in_memory = dummy_interval;
     IntervalWalker iw(this, intervals_in_register, intervals_in_memory);
     const int num_blocks = block_count();
     for (int i = 0; i < num_blocks; i++) {
       BlockBegin* b = block_at(i);
       // register usage is only needed for merging stacks -> compute only
       // when more than one predecessor.
       // the block must not have any spill moves at the beginning (checked by assertions)
       // spill moves would use intervals that are marked as handled and so the usage bit
       // would been set incorrectly
       // NOTE: the check for number_of_preds > 1 is necessary. A block with only one
       //       predecessor may have spill moves at the begin of the block.
       //       If an interval ends at the current instruction id, it is not possible
       //       to decide if the register is live or not at the block begin -> the
       //       register information would be incorrect.
       if (b->number_of_preds() > 1) {
         int id = b->first_lir_instruction_id();
         BitMap regs(FrameMap::nof_fpu_regs);
         regs.clear();
         iw.walk_to(id);   // walk after the first instruction (always a label) of the block
         assert(iw.current_position() == id, "did not walk completely to id");
         // Only consider FPU values in registers
         Interval* interval = iw.active_first(fixedKind);
         while (interval != Interval::end()) {
           int reg = interval->assigned_reg();
           assert(reg >= pd_first_fpu_reg && reg <= pd_last_fpu_reg, "no fpu register");
           assert(interval->assigned_regHi() == -1, "must not have hi register (doubles stored in one register)");
           assert(interval->from() <= id && id < interval->to(), "interval out of range");
 #ifndef PRODUCT
           if (TraceFPURegisterUsage) {
             tty->print("fpu reg %d is live because of ", reg - pd_first_fpu_reg); interval->print();
           }
 #endif
           regs.set_bit(reg - pd_first_fpu_reg);
           interval = interval->next();
         }
         b->set_fpu_register_usage(regs);
 #ifndef PRODUCT
         if (TraceFPURegisterUsage) {
           tty->print("FPU regs for block %d, LIR instr %d): ", b->block_id(), id); regs.print_on(tty); tty->print_cr("");
         }
 #endif
       }
     }
   }
   FpuStackAllocator alloc(ir()->compilation(), this);
   _fpu_stack_allocator = &alloc;
   alloc.allocate();
   _fpu_stack_allocator = NULL;
 }
 FpuStackAllocator::FpuStackAllocator(Compilation* compilation, LinearScan* allocator)
   : _compilation(compilation)
   , _lir(NULL)
   , _pos(-1)
   , _allocator(allocator)
   , _sim(compilation)
   , _temp_sim(compilation)
 {}
 void FpuStackAllocator::allocate() {
   int num_blocks = allocator()->block_count();
   for (int i = 0; i < num_blocks; i++) {
     // Set up to process block
     BlockBegin* block = allocator()->block_at(i);
     intArray* fpu_stack_state = block->fpu_stack_state();
 #ifndef PRODUCT
     if (TraceFPUStack) {
       tty->cr();
       tty->print_cr("------- Begin of new Block %d -------", block->block_id());
     }
 #endif
     assert(fpu_stack_state != NULL ||
            block->end()->as_Base() != NULL ||
            block->is_set(BlockBegin::exception_entry_flag),
            "FPU stack state must be present due to linear-scan order for FPU stack allocation");
     // note: exception handler entries always start with an empty fpu stack
     //       because stack merging would be too complicated
     if (fpu_stack_state != NULL) {
       sim()->read_state(fpu_stack_state);
     } else {
       sim()->clear();
     }
 #ifndef PRODUCT
     if (TraceFPUStack) {
       tty->print("Reading FPU state for block %d:", block->block_id());
       sim()->print();
       tty->cr();
     }
 #endif
     allocate_block(block);
     CHECK_BAILOUT();
   }
 }
 void FpuStackAllocator::allocate_block(BlockBegin* block) {
   bool processed_merge = false;
   LIR_OpList* insts = block->lir()->instructions_list();
   set_lir(block->lir());
   set_pos(0);
   // Note: insts->length() may change during loop
   while (pos() < insts->length()) {
     LIR_Op* op = insts->at(pos());
     _debug_information_computed = false;
 #ifndef PRODUCT
     if (TraceFPUStack) {
       op->print();
     }
     check_invalid_lir_op(op);
 #endif
     LIR_OpBranch* branch = op->as_OpBranch();
     LIR_Op1* op1 = op->as_Op1();
     LIR_Op2* op2 = op->as_Op2();
     LIR_OpCall* opCall = op->as_OpCall();
     if (branch != NULL && branch->block() != NULL) {
       if (!processed_merge) {
         // propagate stack at first branch to a successor
         processed_merge = true;
         bool required_merge = merge_fpu_stack_with_successors(block);
         assert(!required_merge || branch->cond() == lir_cond_always, "splitting of critical edges should prevent FPU stack mismatches at cond branches");
       }
     } else if (op1 != NULL) {
       handle_op1(op1);
     } else if (op2 != NULL) {
       handle_op2(op2);
     } else if (opCall != NULL) {
       handle_opCall(opCall);
     }
     compute_debug_information(op);
     set_pos(1 + pos());
   }
   // Propagate stack when block does not end with branch
   if (!processed_merge) {
     merge_fpu_stack_with_successors(block);
   }
 }
 void FpuStackAllocator::compute_debug_information(LIR_Op* op) {
   if (!_debug_information_computed && op->id() != -1 && allocator()->has_info(op->id())) {
     visitor.visit(op);
     // exception handling
     if (allocator()->compilation()->has_exception_handlers()) {
       XHandlers* xhandlers = visitor.all_xhandler();
       int n = xhandlers->length();
       for (int k = 0; k < n; k++) {
         allocate_exception_handler(xhandlers->handler_at(k));
       }
     } else {
       assert(visitor.all_xhandler()->length() == 0, "missed exception handler");
     }
     // compute debug information
     int n = visitor.info_count();
     assert(n > 0, "should not visit operation otherwise");
     for (int j = 0; j < n; j++) {
       CodeEmitInfo* info = visitor.info_at(j);
       // Compute debug information
       allocator()->compute_debug_info(info, op->id());
     }
   }
   _debug_information_computed = true;
 }
 void FpuStackAllocator::allocate_exception_handler(XHandler* xhandler) {
   if (!sim()->is_empty()) {
     LIR_List* old_lir = lir();
     int old_pos = pos();
     intArray* old_state = sim()->write_state();
 #ifndef PRODUCT
     if (TraceFPUStack) {
       tty->cr();
       tty->print_cr("------- begin of exception handler -------");
     }
 #endif
     if (xhandler->entry_code() == NULL) {
       // need entry code to clear FPU stack
       LIR_List* entry_code = new LIR_List(_compilation);
       entry_code->jump(xhandler->entry_block());
       xhandler->set_entry_code(entry_code);
     }
     LIR_OpList* insts = xhandler->entry_code()->instructions_list();
     set_lir(xhandler->entry_code());
     set_pos(0);
     // Note: insts->length() may change during loop
     while (pos() < insts->length()) {
       LIR_Op* op = insts->at(pos());
 #ifndef PRODUCT
       if (TraceFPUStack) {
         op->print();
       }
       check_invalid_lir_op(op);
 #endif
       switch (op->code()) {
         case lir_move:
           assert(op->as_Op1() != NULL, "must be LIR_Op1");
           assert(pos() != insts->length() - 1, "must not be last operation");
           handle_op1((LIR_Op1*)op);
           break;
         case lir_branch:
           assert(op->as_OpBranch()->cond() == lir_cond_always, "must be unconditional branch");
           assert(pos() == insts->length() - 1, "must be last operation");
           // remove all remaining dead registers from FPU stack
           clear_fpu_stack(LIR_OprFact::illegalOpr);
           break;
         default:
           // other operations not allowed in exception entry code
           ShouldNotReachHere();
       }
       set_pos(pos() + 1);
     }
 #ifndef PRODUCT
     if (TraceFPUStack) {
       tty->cr();
       tty->print_cr("------- end of exception handler -------");
     }
 #endif
     set_lir(old_lir);
     set_pos(old_pos);
     sim()->read_state(old_state);
   }
 }
 int FpuStackAllocator::fpu_num(LIR_Opr opr) {
   assert(opr->is_fpu_register() && !opr->is_xmm_register(), "shouldn't call this otherwise");
   return opr->is_single_fpu() ? opr->fpu_regnr() : opr->fpu_regnrLo();
 }
 int FpuStackAllocator::tos_offset(LIR_Opr opr) {
   return sim()->offset_from_tos(fpu_num(opr));
 }
 LIR_Opr FpuStackAllocator::to_fpu_stack(LIR_Opr opr) {
   assert(opr->is_fpu_register() && !opr->is_xmm_register(), "shouldn't call this otherwise");
   int stack_offset = tos_offset(opr);
   if (opr->is_single_fpu()) {
     return LIR_OprFact::single_fpu(stack_offset)->make_fpu_stack_offset();
   } else {
     assert(opr->is_double_fpu(), "shouldn't call this otherwise");
     return LIR_OprFact::double_fpu(stack_offset)->make_fpu_stack_offset();
   }
 }
 LIR_Opr FpuStackAllocator::to_fpu_stack_top(LIR_Opr opr, bool dont_check_offset) {
   assert(opr->is_fpu_register() && !opr->is_xmm_register(), "shouldn't call this otherwise");
   assert(dont_check_offset || tos_offset(opr) == 0, "operand is not on stack top");
   int stack_offset = 0;
   if (opr->is_single_fpu()) {
     return LIR_OprFact::single_fpu(stack_offset)->make_fpu_stack_offset();
   } else {
     assert(opr->is_double_fpu(), "shouldn't call this otherwise");
     return LIR_OprFact::double_fpu(stack_offset)->make_fpu_stack_offset();
   }
 }
 void FpuStackAllocator::insert_op(LIR_Op* op) {
   lir()->insert_before(pos(), op);
   set_pos(1 + pos());
 }
 void FpuStackAllocator::insert_exchange(int offset) {
   if (offset > 0) {
     LIR_Op1* fxch_op = new LIR_Op1(lir_fxch, LIR_OprFact::intConst(offset), LIR_OprFact::illegalOpr);
     insert_op(fxch_op);
     sim()->swap(offset);
 #ifndef PRODUCT
     if (TraceFPUStack) {
       tty->print("Exchanged register: %d         New state: ", sim()->get_slot(0)); sim()->print(); tty->cr();
     }
 #endif
   }
 }
 void FpuStackAllocator::insert_exchange(LIR_Opr opr) {
   insert_exchange(tos_offset(opr));
 }
 void FpuStackAllocator::insert_free(int offset) {
   // move stack slot to the top of stack and then pop it
   insert_exchange(offset);
   LIR_Op* fpop = new LIR_Op0(lir_fpop_raw);
   insert_op(fpop);
   sim()->pop();
 #ifndef PRODUCT
     if (TraceFPUStack) {
       tty->print("Inserted pop                   New state: "); sim()->print(); tty->cr();
     }
 #endif
 }
 void FpuStackAllocator::insert_free_if_dead(LIR_Opr opr) {
   if (sim()->contains(fpu_num(opr))) {
     int res_slot = tos_offset(opr);
     insert_free(res_slot);
   }
 }
 void FpuStackAllocator::insert_free_if_dead(LIR_Opr opr, LIR_Opr ignore) {
   if (fpu_num(opr) != fpu_num(ignore) && sim()->contains(fpu_num(opr))) {
     int res_slot = tos_offset(opr);
     insert_free(res_slot);
   }
 }
 void FpuStackAllocator::insert_copy(LIR_Opr from, LIR_Opr to) {
   int offset = tos_offset(from);
   LIR_Op1* fld = new LIR_Op1(lir_fld, LIR_OprFact::intConst(offset), LIR_OprFact::illegalOpr);
   insert_op(fld);
   sim()->push(fpu_num(to));
 #ifndef PRODUCT
   if (TraceFPUStack) {
     tty->print("Inserted copy (%d -> %d)         New state: ", fpu_num(from), fpu_num(to)); sim()->print(); tty->cr();
   }
 #endif
 }
 void FpuStackAllocator::do_rename(LIR_Opr from, LIR_Opr to) {
   sim()->rename(fpu_num(from), fpu_num(to));
 }
 void FpuStackAllocator::do_push(LIR_Opr opr) {
   sim()->push(fpu_num(opr));
 }
 void FpuStackAllocator::pop_if_last_use(LIR_Op* op, LIR_Opr opr) {
   assert(op->fpu_pop_count() == 0, "fpu_pop_count alredy set");
   assert(tos_offset(opr) == 0, "can only pop stack top");
   if (opr->is_last_use()) {
     op->set_fpu_pop_count(1);
     sim()->pop();
   }
 }
 void FpuStackAllocator::pop_always(LIR_Op* op, LIR_Opr opr) {
   assert(op->fpu_pop_count() == 0, "fpu_pop_count alredy set");
   assert(tos_offset(opr) == 0, "can only pop stack top");
   op->set_fpu_pop_count(1);
   sim()->pop();
 }
 void FpuStackAllocator::clear_fpu_stack(LIR_Opr preserve) {
   int result_stack_size = (preserve->is_fpu_register() && !preserve->is_xmm_register() ? 1 : 0);
   while (sim()->stack_size() > result_stack_size) {
     assert(!sim()->slot_is_empty(0), "not allowed");
     if (result_stack_size == 0 || sim()->get_slot(0) != fpu_num(preserve)) {
       insert_free(0);
     } else {
       // move "preserve" to bottom of stack so that all other stack slots can be popped
       insert_exchange(sim()->stack_size() - 1);
     }
   }
 }
 void FpuStackAllocator::handle_op1(LIR_Op1* op1) {
   LIR_Opr in  = op1->in_opr();
   LIR_Opr res = op1->result_opr();
   LIR_Opr new_in  = in;  // new operands relative to the actual fpu stack top
   LIR_Opr new_res = res;
   // Note: this switch is processed for all LIR_Op1, regardless if they have FPU-arguments,
   //       so checks for is_float_kind() are necessary inside the cases
   switch (op1->code()) {
     case lir_return: {
       // FPU-Stack must only contain the (optional) fpu return value.
       // All remaining dead values are popped from the stack
       // If the input operand is a fpu-register, it is exchanged to the bottom of the stack
       clear_fpu_stack(in);
       if (in->is_fpu_register() && !in->is_xmm_register()) {
         new_in = to_fpu_stack_top(in);
       }
       break;
     }
     case lir_move: {
       if (in->is_fpu_register() && !in->is_xmm_register()) {
         if (res->is_xmm_register()) {
           // move from fpu register to xmm register (necessary for operations that
           // are not available in the SSE instruction set)
           insert_exchange(in);
           new_in = to_fpu_stack_top(in);
           pop_always(op1, in);
         } else if (res->is_fpu_register() && !res->is_xmm_register()) {
           // move from fpu-register to fpu-register:
           // * input and result register equal:
           //   nothing to do
           // * input register is last use:
           //   rename the input register to result register -> input register
           //   not present on fpu-stack afterwards
           // * input register not last use:
           //   duplicate input register to result register to preserve input
           //
           // Note: The LIR-Assembler does not produce any code for fpu register moves,
           //       so input and result stack index must be equal
           if (fpu_num(in) == fpu_num(res)) {
             // nothing to do
           } else if (in->is_last_use()) {
             insert_free_if_dead(res);//, in);
             do_rename(in, res);
           } else {
             insert_free_if_dead(res);
             insert_copy(in, res);
           }
           new_in = to_fpu_stack(res);
           new_res = new_in;
         } else {
           // move from fpu-register to memory
           // input operand must be on top of stack
           insert_exchange(in);
           // create debug information here because afterwards the register may have been popped
           compute_debug_information(op1);
           new_in = to_fpu_stack_top(in);
           pop_if_last_use(op1, in);
         }
       } else if (res->is_fpu_register() && !res->is_xmm_register()) {
         // move from memory/constant to fpu register
         // result is pushed on the stack
         insert_free_if_dead(res);
         // create debug information before register is pushed
         compute_debug_information(op1);
         do_push(res);
         new_res = to_fpu_stack_top(res);
       }
       break;
     }
     case lir_neg: {
       if (in->is_fpu_register() && !in->is_xmm_register()) {
         assert(res->is_fpu_register() && !res->is_xmm_register(), "must be");
         assert(in->is_last_use(), "old value gets destroyed");
         insert_free_if_dead(res, in);
         insert_exchange(in);
         new_in = to_fpu_stack_top(in);
         do_rename(in, res);
         new_res = to_fpu_stack_top(res);
       }
       break;
     }
     case lir_convert: {
       Bytecodes::Code bc = op1->as_OpConvert()->bytecode();
       switch (bc) {
         case Bytecodes::_d2f:
         case Bytecodes::_f2d:
           assert(res->is_fpu_register(), "must be");
           assert(in->is_fpu_register(), "must be");
           if (!in->is_xmm_register() && !res->is_xmm_register()) {
             // this is quite the same as a move from fpu-register to fpu-register
             // Note: input and result operands must have different types
             if (fpu_num(in) == fpu_num(res)) {
               // nothing to do
               new_in = to_fpu_stack(in);
             } else if (in->is_last_use()) {
               insert_free_if_dead(res);//, in);
               new_in = to_fpu_stack(in);
               do_rename(in, res);
             } else {
               insert_free_if_dead(res);
               insert_copy(in, res);
               new_in = to_fpu_stack_top(in, true);
             }
             new_res = to_fpu_stack(res);
           }
           break;
         case Bytecodes::_i2f:
         case Bytecodes::_l2f:
         case Bytecodes::_i2d:
         case Bytecodes::_l2d:
           assert(res->is_fpu_register(), "must be");
           if (!res->is_xmm_register()) {
             insert_free_if_dead(res);
             do_push(res);
             new_res = to_fpu_stack_top(res);
           }
           break;
         case Bytecodes::_f2i:
         case Bytecodes::_d2i:
           assert(in->is_fpu_register(), "must be");
           if (!in->is_xmm_register()) {
             insert_exchange(in);
             new_in = to_fpu_stack_top(in);
             // TODO: update registes of stub
           }
           break;
         case Bytecodes::_f2l:
         case Bytecodes::_d2l:
           assert(in->is_fpu_register(), "must be");
           if (!in->is_xmm_register()) {
             insert_exchange(in);
             new_in = to_fpu_stack_top(in);
             pop_always(op1, in);
           }
           break;
         case Bytecodes::_i2l:
         case Bytecodes::_l2i:
         case Bytecodes::_i2b:
         case Bytecodes::_i2c:
         case Bytecodes::_i2s:
           // no fpu operands
           break;
         default:
           ShouldNotReachHere();
       }
       break;
     }
     case lir_roundfp: {
       assert(in->is_fpu_register() && !in->is_xmm_register(), "input must be in register");
       assert(res->is_stack(), "result must be on stack");
       insert_exchange(in);
       new_in = to_fpu_stack_top(in);
       pop_if_last_use(op1, in);
       break;
     }
     default: {
       assert(!in->is_float_kind() && !res->is_float_kind(), "missed a fpu-operation");
     }
   }
   op1->set_in_opr(new_in);
   op1->set_result_opr(new_res);
 }
 void FpuStackAllocator::handle_op2(LIR_Op2* op2) {
   LIR_Opr left  = op2->in_opr1();
   if (!left->is_float_kind()) {
     return;
   }
   if (left->is_xmm_register()) {
     return;
   }
   LIR_Opr right = op2->in_opr2();
   LIR_Opr res   = op2->result_opr();
   LIR_Opr new_left  = left;  // new operands relative to the actual fpu stack top
   LIR_Opr new_right = right;
   LIR_Opr new_res   = res;
   assert(!left->is_xmm_register() && !right->is_xmm_register() && !res->is_xmm_register(), "not for xmm registers");
   switch (op2->code()) {
     case lir_cmp:
     case lir_cmp_fd2i:
     case lir_ucmp_fd2i: {
       assert(left->is_fpu_register(), "invalid LIR");
       assert(right->is_fpu_register(), "invalid LIR");
       // the left-hand side must be on top of stack.
       // the right-hand side is never popped, even if is_last_use is set
       insert_exchange(left);
       new_left = to_fpu_stack_top(left);
       new_right = to_fpu_stack(right);
       pop_if_last_use(op2, left);
       break;
     }
     case lir_mul_strictfp:
     case lir_div_strictfp: {
       assert(op2->tmp_opr()->is_fpu_register(), "strict operations need temporary fpu stack slot");
       insert_free_if_dead(op2->tmp_opr());
       assert(sim()->stack_size() <= 7, "at least one stack slot must be free");
       // fall-through: continue with the normal handling of lir_mul and lir_div
     }
     case lir_add:
     case lir_sub:
     case lir_mul:
     case lir_div: {
       assert(left->is_fpu_register(), "must be");
       assert(res->is_fpu_register(), "must be");
       assert(left->is_equal(res), "must be");
       // either the left-hand or the right-hand side must be on top of stack
       // (if right is not a register, left must be on top)
       if (!right->is_fpu_register()) {
         insert_exchange(left);
         new_left = to_fpu_stack_top(left);
       } else {
         // no exchange necessary if right is alredy on top of stack
         if (tos_offset(right) == 0) {
           new_left = to_fpu_stack(left);
           new_right = to_fpu_stack_top(right);
         } else {
           insert_exchange(left);
           new_left = to_fpu_stack_top(left);
           new_right = to_fpu_stack(right);
         }
         if (right->is_last_use()) {
           op2->set_fpu_pop_count(1);
           if (tos_offset(right) == 0) {
             sim()->pop();
           } else {
             // if left is on top of stack, the result is placed in the stack
             // slot of right, so a renaming from right to res is necessary
             assert(tos_offset(left) == 0, "must be");
             sim()->pop();
             do_rename(right, res);
           }
         }
       }
       new_res = to_fpu_stack(res);
       break;
     }
     case lir_rem: {
       assert(left->is_fpu_register(), "must be");
       assert(right->is_fpu_register(), "must be");
       assert(res->is_fpu_register(), "must be");
       assert(left->is_equal(res), "must be");
       // Must bring both operands to top of stack with following operand ordering:
       // * fpu stack before rem: ... right left
       // * fpu stack after rem:  ... left
       if (tos_offset(right) != 1) {
         insert_exchange(right);
         insert_exchange(1);
       }
       insert_exchange(left);
       assert(tos_offset(right) == 1, "check");
       assert(tos_offset(left) == 0, "check");
       new_left = to_fpu_stack_top(left);
       new_right = to_fpu_stack(right);
       op2->set_fpu_pop_count(1);
       sim()->pop();
       do_rename(right, res);
       new_res = to_fpu_stack_top(res);
       break;
     }
     case lir_log:
     case lir_log10:
     case lir_abs:
     case lir_sqrt: {
       // Right argument appears to be unused
       assert(right->is_illegal(), "must be");
       assert(left->is_fpu_register(), "must be");
       assert(res->is_fpu_register(), "must be");
       assert(left->is_last_use(), "old value gets destroyed");
       insert_free_if_dead(res, left);
       insert_exchange(left);
       do_rename(left, res);
       new_left = to_fpu_stack_top(res);
       new_res = new_left;
       op2->set_fpu_stack_size(sim()->stack_size());
       break;
     }
     case lir_tan:
     case lir_sin:
     case lir_cos: {
       // sin and cos need two temporary fpu stack slots, so there are two temporary
       // registers (stored in right and temp of the operation).
       // the stack allocator must guarantee that the stack slots are really free,
       // otherwise there might be a stack overflow.
       assert(left->is_fpu_register(), "must be");
       assert(res->is_fpu_register(), "must be");
       // assert(left->is_last_use(), "old value gets destroyed");
       assert(right->is_fpu_register(), "right is used as the first temporary register");
       assert(op2->tmp_opr()->is_fpu_register(), "temp is used as the second temporary register");
       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");
       insert_free_if_dead(right);
       insert_free_if_dead(op2->tmp_opr());
       insert_free_if_dead(res, left);
       insert_exchange(left);
       do_rename(left, res);
       new_left = to_fpu_stack_top(res);
       new_res = new_left;
       op2->set_fpu_stack_size(sim()->stack_size());
       assert(sim()->stack_size() <= 6, "at least two stack slots must be free");
       break;
     }
     default: {
       assert(false, "missed a fpu-operation");
     }
   }
   op2->set_in_opr1(new_left);
   op2->set_in_opr2(new_right);
   op2->set_result_opr(new_res);
 }
 void FpuStackAllocator::handle_opCall(LIR_OpCall* opCall) {
   LIR_Opr res = opCall->result_opr();
   // clear fpu-stack before call
   // it may contain dead values that could not have been remved by previous operations
   clear_fpu_stack(LIR_OprFact::illegalOpr);
   assert(sim()->is_empty(), "fpu stack must be empty now");
   // compute debug information before (possible) fpu result is pushed
   compute_debug_information(opCall);
   if (res->is_fpu_register() && !res->is_xmm_register()) {
     do_push(res);
     opCall->set_result_opr(to_fpu_stack_top(res));
   }
 }
 #ifndef PRODUCT
 void FpuStackAllocator::check_invalid_lir_op(LIR_Op* op) {
   switch (op->code()) {
     case lir_24bit_FPU:
     case lir_reset_FPU:
     case lir_ffree:
       assert(false, "operations not allowed in lir. If one of these operations is needed, check if they have fpu operands");
       break;
     case lir_fpop_raw:
     case lir_fxch:
     case lir_fld:
       assert(false, "operations only inserted by FpuStackAllocator");
       break;
   }
 }
 #endif
 void FpuStackAllocator::merge_insert_add(LIR_List* instrs, FpuStackSim* cur_sim, int reg) {
   LIR_Op1* move = new LIR_Op1(lir_move, LIR_OprFact::doubleConst(0), LIR_OprFact::double_fpu(reg)->make_fpu_stack_offset());
   instrs->instructions_list()->push(move);
   cur_sim->push(reg);
   move->set_result_opr(to_fpu_stack(move->result_opr()));
   #ifndef PRODUCT
     if (TraceFPUStack) {
       tty->print("Added new register: %d         New state: ", reg); cur_sim->print(); tty->cr();
     }
   #endif
 }
 void FpuStackAllocator::merge_insert_xchg(LIR_List* instrs, FpuStackSim* cur_sim, int slot) {
   assert(slot > 0, "no exchange necessary");
   LIR_Op1* fxch = new LIR_Op1(lir_fxch, LIR_OprFact::intConst(slot));
   instrs->instructions_list()->push(fxch);
   cur_sim->swap(slot);
   #ifndef PRODUCT
     if (TraceFPUStack) {
       tty->print("Exchanged register: %d         New state: ", cur_sim->get_slot(slot)); cur_sim->print(); tty->cr();
     }
   #endif
 }
 void FpuStackAllocator::merge_insert_pop(LIR_List* instrs, FpuStackSim* cur_sim) {
   int reg = cur_sim->get_slot(0);
   LIR_Op* fpop = new LIR_Op0(lir_fpop_raw);
   instrs->instructions_list()->push(fpop);
   cur_sim->pop(reg);
   #ifndef PRODUCT
     if (TraceFPUStack) {
       tty->print("Removed register: %d           New state: ", reg); cur_sim->print(); tty->cr();
     }
   #endif
 }
 bool FpuStackAllocator::merge_rename(FpuStackSim* cur_sim, FpuStackSim* sux_sim, int start_slot, int change_slot) {
   int reg = cur_sim->get_slot(change_slot);
   for (int slot = start_slot; slot >= 0; slot--) {
     int new_reg = sux_sim->get_slot(slot);
     if (!cur_sim->contains(new_reg)) {
       cur_sim->set_slot(change_slot, new_reg);
       #ifndef PRODUCT
         if (TraceFPUStack) {
           tty->print("Renamed register %d to %d       New state: ", reg, new_reg); cur_sim->print(); tty->cr();
         }
       #endif
       return true;
     }
   }
   return false;
 }
 void FpuStackAllocator::merge_fpu_stack(LIR_List* instrs, FpuStackSim* cur_sim, FpuStackSim* sux_sim) {
 #ifndef PRODUCT
   if (TraceFPUStack) {
     tty->cr();
     tty->print("before merging: pred: "); cur_sim->print(); tty->cr();
     tty->print("                 sux: "); sux_sim->print(); tty->cr();
   }
   int slot;
   for (slot = 0; slot < cur_sim->stack_size(); slot++) {
     assert(!cur_sim->slot_is_empty(slot), "not handled by algorithm");
   }
   for (slot = 0; slot < sux_sim->stack_size(); slot++) {
     assert(!sux_sim->slot_is_empty(slot), "not handled by algorithm");
   }
 #endif
   // size difference between cur and sux that must be resolved by adding or removing values form the stack
   int size_diff = cur_sim->stack_size() - sux_sim->stack_size();
   if (!ComputeExactFPURegisterUsage) {
     // add slots that are currently free, but used in successor
     // When the exact FPU register usage is computed, the stack does
     // not contain dead values at merging -> no values must be added
     int sux_slot = sux_sim->stack_size() - 1;
     while (size_diff < 0) {
       assert(sux_slot >= 0, "slot out of bounds -> error in algorithm");
       int reg = sux_sim->get_slot(sux_slot);
       if (!cur_sim->contains(reg)) {
         merge_insert_add(instrs, cur_sim, reg);
         size_diff++;
         if (sux_slot + size_diff != 0) {
           merge_insert_xchg(instrs, cur_sim, sux_slot + size_diff);
         }
       }
      sux_slot--;
     }
   }
   assert(cur_sim->stack_size() >= sux_sim->stack_size(), "stack size must be equal or greater now");
   assert(size_diff == cur_sim->stack_size() - sux_sim->stack_size(), "must be");
   // stack merge algorithm:
   // 1) as long as the current stack top is not in the right location (that meens
   //    it should not be on the stack top), exchange it into the right location
   // 2) if the stack top is right, but the remaining stack is not ordered correctly,
   //    the stack top is exchanged away to get another value on top ->
   //    now step 1) can be continued
   // the stack can also contain unused items -> these items are removed from stack
   int finished_slot = sux_sim->stack_size() - 1;
   while (finished_slot >= 0 || size_diff > 0) {
     while (size_diff > 0 || (cur_sim->stack_size() > 0 && cur_sim->get_slot(0) != sux_sim->get_slot(0))) {
       int reg = cur_sim->get_slot(0);
       if (sux_sim->contains(reg)) {
         int sux_slot = sux_sim->offset_from_tos(reg);
         merge_insert_xchg(instrs, cur_sim, sux_slot + size_diff);
       } else if (!merge_rename(cur_sim, sux_sim, finished_slot, 0)) {
         assert(size_diff > 0, "must be");
         merge_insert_pop(instrs, cur_sim);
         size_diff--;
       }
       assert(cur_sim->stack_size() == 0 || cur_sim->get_slot(0) != reg, "register must have been changed");
     }
     while (finished_slot >= 0 && cur_sim->get_slot(finished_slot) == sux_sim->get_slot(finished_slot)) {
       finished_slot--;
     }
     if (finished_slot >= 0) {
       int reg = cur_sim->get_slot(finished_slot);
       if (sux_sim->contains(reg) || !merge_rename(cur_sim, sux_sim, finished_slot, finished_slot)) {
         assert(sux_sim->contains(reg) || size_diff > 0, "must be");
         merge_insert_xchg(instrs, cur_sim, finished_slot);
       }
       assert(cur_sim->get_slot(finished_slot) != reg, "register must have been changed");
     }
   }
 #ifndef PRODUCT
   if (TraceFPUStack) {
     tty->print("after merging:  pred: "); cur_sim->print(); tty->cr();
     tty->print("                 sux: "); sux_sim->print(); tty->cr();
     tty->cr();
   }
 #endif
   assert(cur_sim->stack_size() == sux_sim->stack_size(), "stack size must be equal now");
 }
 void FpuStackAllocator::merge_cleanup_fpu_stack(LIR_List* instrs, FpuStackSim* cur_sim, BitMap& live_fpu_regs) {
 #ifndef PRODUCT
   if (TraceFPUStack) {
     tty->cr();
     tty->print("before cleanup: state: "); cur_sim->print(); tty->cr();
     tty->print("                live:  "); live_fpu_regs.print_on(tty); tty->cr();
   }
 #endif
   int slot = 0;
   while (slot < cur_sim->stack_size()) {
     int reg = cur_sim->get_slot(slot);
     if (!live_fpu_regs.at(reg)) {
       if (slot != 0) {
         merge_insert_xchg(instrs, cur_sim, slot);
       }
       merge_insert_pop(instrs, cur_sim);
     } else {
       slot++;
     }
   }
 #ifndef PRODUCT
   if (TraceFPUStack) {
     tty->print("after cleanup:  state: "); cur_sim->print(); tty->cr();
     tty->print("                live:  "); live_fpu_regs.print_on(tty); tty->cr();
     tty->cr();
   }
   // check if fpu stack only contains live registers
   for (unsigned int i = 0; i < live_fpu_regs.size(); i++) {
     if (live_fpu_regs.at(i) != cur_sim->contains(i)) {
       tty->print_cr("mismatch between required and actual stack content");
       break;
     }
   }
 #endif
 }
 bool FpuStackAllocator::merge_fpu_stack_with_successors(BlockBegin* block) {
 #ifndef PRODUCT
   if (TraceFPUStack) {
     tty->print_cr("Propagating FPU stack state for B%d at LIR_Op position %d to successors:",
                   block->block_id(), pos());
     sim()->print();
     tty->cr();
   }
 #endif
   bool changed = false;
   int number_of_sux = block->number_of_sux();
   if (number_of_sux == 1 && block->sux_at(0)->number_of_preds() > 1) {
     // The successor has at least two incoming edges, so a stack merge will be necessary
     // If this block is the first predecessor, cleanup the current stack and propagate it
     // If this block is not the first predecessor, a stack merge will be necessary
     BlockBegin* sux = block->sux_at(0);
     intArray* state = sux->fpu_stack_state();
     LIR_List* instrs = new LIR_List(_compilation);
     if (state != NULL) {
       // Merge with a successors that already has a FPU stack state
       // the block must only have one successor because critical edges must been split
       FpuStackSim* cur_sim = sim();
       FpuStackSim* sux_sim = temp_sim();
       sux_sim->read_state(state);
       merge_fpu_stack(instrs, cur_sim, sux_sim);
     } else {
       // propagate current FPU stack state to successor without state
       // clean up stack first so that there are no dead values on the stack
       if (ComputeExactFPURegisterUsage) {
         FpuStackSim* cur_sim = sim();
         BitMap live_fpu_regs = block->sux_at(0)->fpu_register_usage();
         assert(live_fpu_regs.size() == FrameMap::nof_fpu_regs, "missing register usage");
         merge_cleanup_fpu_stack(instrs, cur_sim, live_fpu_regs);
       }
       intArray* state = sim()->write_state();
       if (TraceFPUStack) {
         tty->print_cr("Setting FPU stack state of B%d (merge path)", sux->block_id());
         sim()->print(); tty->cr();
       }
       sux->set_fpu_stack_state(state);
     }
     if (instrs->instructions_list()->length() > 0) {
       lir()->insert_before(pos(), instrs);
       set_pos(instrs->instructions_list()->length() + pos());
       changed = true;
     }
   } else {
     // Propagate unmodified Stack to successors where a stack merge is not necessary
     intArray* state = sim()->write_state();
     for (int i = 0; i < number_of_sux; i++) {
       BlockBegin* sux = block->sux_at(i);
 #ifdef ASSERT
       for (int j = 0; j < sux->number_of_preds(); j++) {
         assert(block == sux->pred_at(j), "all critical edges must be broken");
       }
       // check if new state is same
       if (sux->fpu_stack_state() != NULL) {
         intArray* sux_state = sux->fpu_stack_state();
         assert(state->length() == sux_state->length(), "overwriting existing stack state");
         for (int j = 0; j < state->length(); j++) {
           assert(state->at(j) == sux_state->at(j), "overwriting existing stack state");
         }
       }
 #endif
 #ifndef PRODUCT
       if (TraceFPUStack) {
         tty->print_cr("Setting FPU stack state of B%d", sux->block_id());
         sim()->print(); tty->cr();
       }
 #endif
       sux->set_fpu_stack_state(state);
     }
   }
 #ifndef PRODUCT
   // assertions that FPU stack state conforms to all successors' states
   intArray* cur_state = sim()->write_state();
   for (int i = 0; i < number_of_sux; i++) {
     BlockBegin* sux = block->sux_at(i);
     intArray* sux_state = sux->fpu_stack_state();
     assert(sux_state != NULL, "no fpu state");
     assert(cur_state->length() == sux_state->length(), "incorrect length");
     for (int i = 0; i < cur_state->length(); i++) {
       assert(cur_state->at(i) == sux_state->at(i), "element not equal");
     }
   }
 #endif
   return changed;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/cpu/x86/vm/c1_LinearScan_x86.cpp@18a08a7e16b5 (annotated)

src/cpu/x86/vm/c1_LinearScan_x86.cpp