jdk8-mips64-public/hotspot: src/share/vm/adlc/formsopt.cpp@a9becfeecd1b (annotated)

src/share/vm/adlc/formsopt.cpp@a9becfeecd1b (annotated)

src/share/vm/adlc/formsopt.cpp

Wed, 22 Jan 2014 17:42:23 -0800

author: kvn
date: Wed, 22 Jan 2014 17:42:23 -0800
changeset 6503: a9becfeecd1b
parent 3882: 8c92982cbbc4
child 6876: 710a3c8b516e
child 7853: a1642365d69f
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 1998, 2012, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 // FORMS.CPP - Definitions for ADL Parser Forms Classes
 #include "adlc.hpp"
 //==============================Register Allocation============================
 int RegisterForm::_reg_ctr = 0;
 //------------------------------RegisterForm-----------------------------------
 // Constructor
 RegisterForm::RegisterForm()
   : _regDef(cmpstr,hashstr, Form::arena),
     _regClass(cmpstr,hashstr, Form::arena),
     _allocClass(cmpstr,hashstr, Form::arena) {
 }
 RegisterForm::~RegisterForm() {
 }
 // record a new register definition
 void RegisterForm::addRegDef(char *name, char *callingConv, char *c_conv,
                              char *idealtype, char *encoding, char* concrete) {
   RegDef *regDef = new RegDef(name, callingConv, c_conv, idealtype, encoding, concrete);
   _rdefs.addName(name);
   _regDef.Insert(name,regDef);
 }
 // record a new register class
 RegClass *RegisterForm::addRegClass(const char *className) {
   RegClass *regClass = new RegClass(className);
   _rclasses.addName(className);
   _regClass.Insert(className,regClass);
   return regClass;
 }
 // record a new register class
 AllocClass *RegisterForm::addAllocClass(char *className) {
   AllocClass *allocClass = new AllocClass(className);
   _aclasses.addName(className);
   _allocClass.Insert(className,allocClass);
   return allocClass;
 }
 // Called after parsing the Register block.  Record the register class
 // for spill-slots/regs.
 void RegisterForm::addSpillRegClass() {
   // Stack slots start at the next available even register number.
   _reg_ctr = (_reg_ctr+7) & ~7;
   const char *rc_name   = "stack_slots";
   RegClass   *reg_class = new RegClass(rc_name);
   reg_class->_stack_or_reg = true;
   _rclasses.addName(rc_name);
   _regClass.Insert(rc_name,reg_class);
 }
 // Provide iteration over all register definitions
 // in the order used by the register allocator
 void        RegisterForm::reset_RegDefs() {
   _current_ac = NULL;
   _aclasses.reset();
 }
 RegDef     *RegisterForm::iter_RegDefs() {
   // Check if we need to get the next AllocClass
   if ( _current_ac == NULL ) {
     const char *ac_name = _aclasses.iter();
     if( ac_name == NULL )   return NULL;   // No more allocation classes
     _current_ac = (AllocClass*)_allocClass[ac_name];
     _current_ac->_regDefs.reset();
     assert( _current_ac != NULL, "Name must match an allocation class");
   }
   const char *rd_name = _current_ac->_regDefs.iter();
   if( rd_name == NULL ) {
     // At end of this allocation class, check the next
     _current_ac = NULL;
     return iter_RegDefs();
   }
   RegDef *reg_def = (RegDef*)_current_ac->_regDef[rd_name];
   assert( reg_def != NULL, "Name must match a register definition");
   return reg_def;
 }
 // return the register definition with name 'regName'
 RegDef *RegisterForm::getRegDef(const char *regName) {
   RegDef *regDef = (RegDef*)_regDef[regName];
   return  regDef;
 }
 // return the register class with name 'className'
 RegClass *RegisterForm::getRegClass(const char *className) {
   RegClass *regClass = (RegClass*)_regClass[className];
   return    regClass;
 }
 // Check that register classes are compatible with chunks
 bool   RegisterForm::verify() {
   bool valid = true;
   // Verify Register Classes
   // check that each register class contains registers from one chunk
   const char *rc_name = NULL;
   _rclasses.reset();
   while ( (rc_name = _rclasses.iter()) != NULL ) {
     // Check the chunk value for all registers in this class
     RegClass *reg_class = getRegClass(rc_name);
     assert( reg_class != NULL, "InternalError() no matching register class");
   } // end of RegClasses
   // Verify that every register has been placed into an allocation class
   RegDef *reg_def = NULL;
   reset_RegDefs();
   uint  num_register_zero = 0;
   while ( (reg_def = iter_RegDefs()) != NULL ) {
     if( reg_def->register_num() == 0 )  ++num_register_zero;
   }
   if( num_register_zero > 1 ) {
     fprintf(stderr,
             "ERROR: More than one register has been assigned register-number 0.\n"
             "Probably because a register has not been entered into an allocation class.\n");
   }
   return  valid;
 }
 // Compute RegMask size
 int RegisterForm::RegMask_Size() {
   // Need at least this many words
   int words_for_regs = (_reg_ctr + 31)>>5;
   // The array of Register Mask bits should be large enough to cover
   // all the machine registers and all parameters that need to be passed
   // on the stack (stack registers) up to some interesting limit.  Methods
   // that need more parameters will NOT be compiled.  On Intel, the limit
   // is something like 90+ parameters.
   // Add a few (3 words == 96 bits) for incoming & outgoing arguments to calls.
   // Round up to the next doubleword size.
   return (words_for_regs + 3 + 1) & ~1;
 }
 void RegisterForm::dump() {                  // Debug printer
   output(stderr);
 }
 void RegisterForm::output(FILE *fp) {          // Write info to output files
   const char *name;
   fprintf(fp,"\n");
   fprintf(fp,"-------------------- Dump RegisterForm --------------------\n");
   for(_rdefs.reset(); (name = _rdefs.iter()) != NULL;) {
     ((RegDef*)_regDef[name])->output(fp);
   }
   fprintf(fp,"\n");
   for (_rclasses.reset(); (name = _rclasses.iter()) != NULL;) {
     ((RegClass*)_regClass[name])->output(fp);
   }
   fprintf(fp,"\n");
   for (_aclasses.reset(); (name = _aclasses.iter()) != NULL;) {
     ((AllocClass*)_allocClass[name])->output(fp);
   }
   fprintf(fp,"-------------------- end  RegisterForm --------------------\n");
 }
 //------------------------------RegDef-----------------------------------------
 // Constructor
 RegDef::RegDef(char *regname, char *callconv, char *c_conv, char * idealtype, char * encode, char * concrete)
   : _regname(regname), _callconv(callconv), _c_conv(c_conv),
     _idealtype(idealtype),
     _register_encode(encode),
     _concrete(concrete),
     _register_num(0) {
   // Chunk and register mask are determined by the register number
   // _register_num is set when registers are added to an allocation class
 }
 RegDef::~RegDef() {                      // Destructor
 }
 void RegDef::set_register_num(uint32 register_num) {
   _register_num      = register_num;
 }
 // Bit pattern used for generating machine code
 const char* RegDef::register_encode() const {
   return _register_encode;
 }
 // Register number used in machine-independent code
 uint32 RegDef::register_num()    const {
   return _register_num;
 }
 void RegDef::dump() {
   output(stderr);
 }
 void RegDef::output(FILE *fp) {         // Write info to output files
   fprintf(fp,"RegDef: %s (%s) encode as %s  using number %d\n",
           _regname, (_callconv?_callconv:""), _register_encode, _register_num);
   fprintf(fp,"\n");
 }
 //------------------------------RegClass---------------------------------------
 // Construct a register class into which registers will be inserted
 RegClass::RegClass(const char *classid) : _stack_or_reg(false), _classid(classid), _regDef(cmpstr,hashstr, Form::arena),
                                           _user_defined(NULL)
 {
 }
 // record a register in this class
 void RegClass::addReg(RegDef *regDef) {
   _regDefs.addName(regDef->_regname);
   _regDef.Insert((void*)regDef->_regname, regDef);
 }
 // Number of registers in class
 uint RegClass::size() const {
   return _regDef.Size();
 }
 const RegDef *RegClass::get_RegDef(const char *rd_name) const {
   return  (const RegDef*)_regDef[rd_name];
 }
 void RegClass::reset() {
   _regDefs.reset();
 }
 const char *RegClass::rd_name_iter() {
   return _regDefs.iter();
 }
 RegDef *RegClass::RegDef_iter() {
   const char *rd_name  = rd_name_iter();
   RegDef     *reg_def  = rd_name ? (RegDef*)_regDef[rd_name] : NULL;
   return      reg_def;
 }
 const RegDef* RegClass::find_first_elem() {
   const RegDef* first = NULL;
   const RegDef* def = NULL;
   reset();
   while ((def = RegDef_iter()) != NULL) {
     if (first == NULL || def->register_num() < first->register_num()) {
       first = def;
     }
   }
   assert(first != NULL, "empty mask?");
   return first;;
 }
 // Collect all the registers in this register-word.  One bit per register.
 int RegClass::regs_in_word( int wordnum, bool stack_also ) {
   int         word = 0;
   const char *name;
   for(_regDefs.reset(); (name = _regDefs.iter()) != NULL;) {
     int rnum = ((RegDef*)_regDef[name])->register_num();
     if( (rnum >> 5) == wordnum )
       word |= (1 << (rnum & 31));
   }
   if( stack_also ) {
     // Now also collect stack bits
     for( int i = 0; i < 32; i++ )
       if( wordnum*32+i >= RegisterForm::_reg_ctr )
         word |= (1 << i);
   }
   return word;
 }
 void RegClass::dump() {
   output(stderr);
 }
 void RegClass::output(FILE *fp) {           // Write info to output files
   fprintf(fp,"RegClass: %s\n",_classid);
   const char *name;
   for(_regDefs.reset(); (name = _regDefs.iter()) != NULL;) {
     ((RegDef*)_regDef[name])->output(fp);
   }
   fprintf(fp,"--- done with entries for reg_class %s\n\n",_classid);
 }
 //------------------------------AllocClass-------------------------------------
 AllocClass::AllocClass(char *classid) : _classid(classid), _regDef(cmpstr,hashstr, Form::arena) {
 }
 // record a register in this class
 void AllocClass::addReg(RegDef *regDef) {
   assert( regDef != NULL, "Can not add a NULL to an allocation class");
   regDef->set_register_num( RegisterForm::_reg_ctr++ );
   // Add regDef to this allocation class
   _regDefs.addName(regDef->_regname);
   _regDef.Insert((void*)regDef->_regname, regDef);
 }
 void AllocClass::dump() {
   output(stderr);
 }
 void AllocClass::output(FILE *fp) {       // Write info to output files
   fprintf(fp,"AllocClass: %s \n",_classid);
   const char *name;
   for(_regDefs.reset(); (name = _regDefs.iter()) != NULL;) {
     ((RegDef*)_regDef[name])->output(fp);
   }
   fprintf(fp,"--- done with entries for alloc_class %s\n\n",_classid);
 }
 //==============================Frame Handling=================================
 //------------------------------FrameForm--------------------------------------
 FrameForm::FrameForm() {
   _frame_pointer = NULL;
   _c_frame_pointer = NULL;
   _alignment = NULL;
   _return_addr = NULL;
   _c_return_addr = NULL;
   _in_preserve_slots = NULL;
   _varargs_C_out_slots_killed = NULL;
   _calling_convention = NULL;
   _c_calling_convention = NULL;
   _return_value = NULL;
   _c_return_value = NULL;
   _interpreter_frame_pointer_reg = NULL;
 }
 FrameForm::~FrameForm() {
 }
 void FrameForm::dump() {
   output(stderr);
 }
 void FrameForm::output(FILE *fp) {           // Write info to output files
   fprintf(fp,"\nFrame:\n");
 }
 //==============================Scheduling=====================================
 //------------------------------PipelineForm-----------------------------------
 PipelineForm::PipelineForm()
   :  _reslist               ()
   ,  _resdict               (cmpstr, hashstr, Form::arena)
   ,  _classdict             (cmpstr, hashstr, Form::arena)
   ,  _rescount              (0)
   ,  _maxcycleused          (0)
   ,  _stages                ()
   ,  _stagecnt              (0)
   ,  _classlist             ()
   ,  _classcnt              (0)
   ,  _noplist               ()
   ,  _nopcnt                (0)
   ,  _variableSizeInstrs    (false)
   ,  _branchHasDelaySlot    (false)
   ,  _maxInstrsPerBundle    (0)
   ,  _maxBundlesPerCycle    (1)
   ,  _instrUnitSize         (0)
   ,  _bundleUnitSize        (0)
   ,  _instrFetchUnitSize    (0)
   ,  _instrFetchUnits       (0) {
 }
 PipelineForm::~PipelineForm() {
 }
 void PipelineForm::dump() {
   output(stderr);
 }
 void PipelineForm::output(FILE *fp) {           // Write info to output files
   const char *res;
   const char *stage;
   const char *cls;
   const char *nop;
   int count = 0;
   fprintf(fp,"\nPipeline:");
   if (_variableSizeInstrs)
     if (_instrUnitSize > 0)
       fprintf(fp," variable-sized instructions in %d byte units", _instrUnitSize);
     else
       fprintf(fp," variable-sized instructions");
   else
     if (_instrUnitSize > 0)
       fprintf(fp," fixed-sized instructions of %d bytes", _instrUnitSize);
     else if (_bundleUnitSize > 0)
       fprintf(fp," fixed-sized bundles of %d bytes", _bundleUnitSize);
     else
       fprintf(fp," fixed-sized instructions");
   if (_branchHasDelaySlot)
     fprintf(fp,", branch has delay slot");
   if (_maxInstrsPerBundle > 0)
     fprintf(fp,", max of %d instruction%s in parallel",
       _maxInstrsPerBundle, _maxInstrsPerBundle > 1 ? "s" : "");
   if (_maxBundlesPerCycle > 0)
     fprintf(fp,", max of %d bundle%s in parallel",
       _maxBundlesPerCycle, _maxBundlesPerCycle > 1 ? "s" : "");
   if (_instrFetchUnitSize > 0 && _instrFetchUnits)
     fprintf(fp, ", fetch %d x % d bytes per cycle", _instrFetchUnits, _instrFetchUnitSize);
   fprintf(fp,"\nResource:");
   for ( _reslist.reset(); (res = _reslist.iter()) != NULL; )
     fprintf(fp," %s(0x%08x)", res, _resdict[res]->is_resource()->mask());
   fprintf(fp,"\n");
   fprintf(fp,"\nDescription:\n");
   for ( _stages.reset(); (stage = _stages.iter()) != NULL; )
     fprintf(fp," %s(%d)", stage, count++);
   fprintf(fp,"\n");
   fprintf(fp,"\nClasses:\n");
   for ( _classlist.reset(); (cls = _classlist.iter()) != NULL; )
     _classdict[cls]->is_pipeclass()->output(fp);
   fprintf(fp,"\nNop Instructions:");
   for ( _noplist.reset(); (nop = _noplist.iter()) != NULL; )
     fprintf(fp, " \"%s\"", nop);
   fprintf(fp,"\n");
 }
 //------------------------------ResourceForm-----------------------------------
 ResourceForm::ResourceForm(unsigned resmask)
 : _resmask(resmask) {
 }
 ResourceForm::~ResourceForm() {
 }
 ResourceForm  *ResourceForm::is_resource() const {
   return (ResourceForm *)(this);
 }
 void ResourceForm::dump() {
   output(stderr);
 }
 void ResourceForm::output(FILE *fp) {          // Write info to output files
   fprintf(fp, "resource: 0x%08x;\n", mask());
 }
 //------------------------------PipeClassOperandForm----------------------------------
 void PipeClassOperandForm::dump() {
   output(stderr);
 }
 void PipeClassOperandForm::output(FILE *fp) {         // Write info to output files
   fprintf(stderr,"PipeClassOperandForm: %s", _stage);
   fflush(stderr);
   if (_more_instrs > 0)
     fprintf(stderr,"+%d", _more_instrs);
   fprintf(stderr," (%s)\n", _iswrite ? "write" : "read");
   fflush(stderr);
   fprintf(fp,"PipeClassOperandForm: %s", _stage);
   if (_more_instrs > 0)
     fprintf(fp,"+%d", _more_instrs);
   fprintf(fp," (%s)\n", _iswrite ? "write" : "read");
 }
 //------------------------------PipeClassResourceForm----------------------------------
 void PipeClassResourceForm::dump() {
   output(stderr);
 }
 void PipeClassResourceForm::output(FILE *fp) {         // Write info to output files
   fprintf(fp,"PipeClassResourceForm: %s at stage %s for %d cycles\n",
      _resource, _stage, _cycles);
 }
 //------------------------------PipeClassForm----------------------------------
 PipeClassForm::PipeClassForm(const char *id, int num)
   : _ident(id)
   , _num(num)
   , _localNames(cmpstr, hashstr, Form::arena)
   , _localUsage(cmpstr, hashstr, Form::arena)
   , _has_fixed_latency(0)
   , _fixed_latency(0)
   , _instruction_count(0)
   , _has_multiple_bundles(false)
   , _has_branch_delay_slot(false)
   , _force_serialization(false)
   , _may_have_no_code(false) {
 }
 PipeClassForm::~PipeClassForm() {
 }
 PipeClassForm  *PipeClassForm::is_pipeclass() const {
   return (PipeClassForm *)(this);
 }
 void PipeClassForm::dump() {
   output(stderr);
 }
 void PipeClassForm::output(FILE *fp) {         // Write info to output files
   fprintf(fp,"PipeClassForm: #%03d", _num);
   if (_ident)
      fprintf(fp," \"%s\":", _ident);
   if (_has_fixed_latency)
      fprintf(fp," latency %d", _fixed_latency);
   if (_force_serialization)
      fprintf(fp, ", force serialization");
   if (_may_have_no_code)
      fprintf(fp, ", may have no code");
   fprintf(fp, ", %d instruction%s\n", InstructionCount(), InstructionCount() != 1 ? "s" : "");
 }
 //==============================Peephole Optimization==========================
 int Peephole::_peephole_counter = 0;
 //------------------------------Peephole---------------------------------------
 Peephole::Peephole() : _match(NULL), _constraint(NULL), _replace(NULL), _next(NULL) {
   _peephole_number = _peephole_counter++;
 }
 Peephole::~Peephole() {
 }
 // Append a peephole rule with the same root instruction
 void Peephole::append_peephole(Peephole *next_peephole) {
   if( _next == NULL ) {
     _next = next_peephole;
   } else {
     _next->append_peephole( next_peephole );
   }
 }
 // Store the components of this peephole rule
 void Peephole::add_match(PeepMatch *match) {
   assert( _match == NULL, "fatal()" );
   _match = match;
 }
 void Peephole::append_constraint(PeepConstraint *next_constraint) {
   if( _constraint == NULL ) {
     _constraint = next_constraint;
   } else {
     _constraint->append( next_constraint );
   }
 }
 void Peephole::add_replace(PeepReplace *replace) {
   assert( _replace == NULL, "fatal()" );
   _replace = replace;
 }
 // class Peephole accessor methods are in the declaration.
 void Peephole::dump() {
   output(stderr);
 }
 void Peephole::output(FILE *fp) {         // Write info to output files
   fprintf(fp,"Peephole:\n");
   if( _match != NULL )       _match->output(fp);
   if( _constraint != NULL )  _constraint->output(fp);
   if( _replace != NULL )     _replace->output(fp);
   // Output the next entry
   if( _next ) _next->output(fp);
 }
 //------------------------------PeepMatch--------------------------------------
 PeepMatch::PeepMatch(char *rule) : _max_position(0), _rule(rule) {
 }
 PeepMatch::~PeepMatch() {
 }
 // Insert info into the match-rule
 void  PeepMatch::add_instruction(int parent, int position, const char *name,
                                  int input) {
   if( position > _max_position ) _max_position = position;
   _parent.addName((char*) (intptr_t) parent);
   _position.addName((char*) (intptr_t) position);
   _instrs.addName(name);
   _input.addName((char*) (intptr_t) input);
 }
 // Access info about instructions in the peep-match rule
 int   PeepMatch::max_position() {
   return _max_position;
 }
 const char *PeepMatch::instruction_name(int position) {
   return _instrs.name(position);
 }
 // Iterate through all info on matched instructions
 void  PeepMatch::reset() {
   _parent.reset();
   _position.reset();
   _instrs.reset();
   _input.reset();
 }
 void  PeepMatch::next_instruction(int &parent, int &position, const char* &name, int &input) {
   parent   = (int) (intptr_t) _parent.iter();
   position = (int) (intptr_t) _position.iter();
   name     = _instrs.iter();
   input    = (int) (intptr_t) _input.iter();
 }
 // 'true' if current position in iteration is a placeholder, not matched.
 bool  PeepMatch::is_placeholder() {
   return _instrs.current_is_signal();
 }
 void PeepMatch::dump() {
   output(stderr);
 }
 void PeepMatch::output(FILE *fp) {        // Write info to output files
   fprintf(fp,"PeepMatch:\n");
 }
 //------------------------------PeepConstraint---------------------------------
 PeepConstraint::PeepConstraint(int left_inst,  char* left_op, char* relation,
                                int right_inst, char* right_op)
   : _left_inst(left_inst), _left_op(left_op), _relation(relation),
     _right_inst(right_inst), _right_op(right_op), _next(NULL) {}
 PeepConstraint::~PeepConstraint() {
 }
 // Check if constraints use instruction at position
 bool PeepConstraint::constrains_instruction(int position) {
   // Check local instruction constraints
   if( _left_inst  == position ) return true;
   if( _right_inst == position ) return true;
   // Check remaining constraints in list
   if( _next == NULL )  return false;
   else                 return _next->constrains_instruction(position);
 }
 // Add another constraint
 void PeepConstraint::append(PeepConstraint *next_constraint) {
   if( _next == NULL ) {
     _next = next_constraint;
   } else {
     _next->append( next_constraint );
   }
 }
 // Access the next constraint in the list
 PeepConstraint *PeepConstraint::next() {
   return _next;
 }
 void PeepConstraint::dump() {
   output(stderr);
 }
 void PeepConstraint::output(FILE *fp) {   // Write info to output files
   fprintf(fp,"PeepConstraint:\n");
 }
 //------------------------------PeepReplace------------------------------------
 PeepReplace::PeepReplace(char *rule) : _rule(rule) {
 }
 PeepReplace::~PeepReplace() {
 }
 // Add contents of peepreplace
 void  PeepReplace::add_instruction(char *root) {
   _instruction.addName(root);
   _operand_inst_num.add_signal();
   _operand_op_name.add_signal();
 }
 void  PeepReplace::add_operand( int inst_num, char *inst_operand ) {
   _instruction.add_signal();
   _operand_inst_num.addName((char*) (intptr_t) inst_num);
   _operand_op_name.addName(inst_operand);
 }
 // Access contents of peepreplace
 void  PeepReplace::reset() {
   _instruction.reset();
   _operand_inst_num.reset();
   _operand_op_name.reset();
 }
 void  PeepReplace::next_instruction(const char* &inst){
   inst                     = _instruction.iter();
   int         inst_num     = (int) (intptr_t) _operand_inst_num.iter();
   const char* inst_operand = _operand_op_name.iter();
 }
 void  PeepReplace::next_operand(int &inst_num, const char* &inst_operand) {
   const char* inst = _instruction.iter();
   inst_num         = (int) (intptr_t) _operand_inst_num.iter();
   inst_operand     = _operand_op_name.iter();
 }
 void PeepReplace::dump() {
   output(stderr);
 }
 void PeepReplace::output(FILE *fp) {      // Write info to output files
   fprintf(fp,"PeepReplace:\n");
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/adlc/formsopt.cpp@a9becfeecd1b (annotated)

src/share/vm/adlc/formsopt.cpp