src/share/vm/opto/addnode.cpp

Tue, 28 Jul 2009 12:12:40 -0700

author
xdono
date
Tue, 28 Jul 2009 12:12:40 -0700
changeset 1279
bd02caa94611
parent 1077
660978a2a31a
child 1896
b5fdf39b9749
permissions
-rw-r--r--

6862919: Update copyright year
Summary: Update copyright for files that have been modified in 2009, up to 07/09
Reviewed-by: tbell, ohair

     1 /*
     2  * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 // Portions of code courtesy of Clifford Click
    27 #include "incls/_precompiled.incl"
    28 #include "incls/_addnode.cpp.incl"
    30 #define MAXFLOAT        ((float)3.40282346638528860e+38)
    32 // Classic Add functionality.  This covers all the usual 'add' behaviors for
    33 // an algebraic ring.  Add-integer, add-float, add-double, and binary-or are
    34 // all inherited from this class.  The various identity values are supplied
    35 // by virtual functions.
    38 //=============================================================================
    39 //------------------------------hash-------------------------------------------
    40 // Hash function over AddNodes.  Needs to be commutative; i.e., I swap
    41 // (commute) inputs to AddNodes willy-nilly so the hash function must return
    42 // the same value in the presence of edge swapping.
    43 uint AddNode::hash() const {
    44   return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode();
    45 }
    47 //------------------------------Identity---------------------------------------
    48 // If either input is a constant 0, return the other input.
    49 Node *AddNode::Identity( PhaseTransform *phase ) {
    50   const Type *zero = add_id();  // The additive identity
    51   if( phase->type( in(1) )->higher_equal( zero ) ) return in(2);
    52   if( phase->type( in(2) )->higher_equal( zero ) ) return in(1);
    53   return this;
    54 }
    56 //------------------------------commute----------------------------------------
    57 // Commute operands to move loads and constants to the right.
    58 static bool commute( Node *add, int con_left, int con_right ) {
    59   Node *in1 = add->in(1);
    60   Node *in2 = add->in(2);
    62   // Convert "1+x" into "x+1".
    63   // Right is a constant; leave it
    64   if( con_right ) return false;
    65   // Left is a constant; move it right.
    66   if( con_left ) {
    67     add->swap_edges(1, 2);
    68     return true;
    69   }
    71   // Convert "Load+x" into "x+Load".
    72   // Now check for loads
    73   if (in2->is_Load()) {
    74     if (!in1->is_Load()) {
    75       // already x+Load to return
    76       return false;
    77     }
    78     // both are loads, so fall through to sort inputs by idx
    79   } else if( in1->is_Load() ) {
    80     // Left is a Load and Right is not; move it right.
    81     add->swap_edges(1, 2);
    82     return true;
    83   }
    85   PhiNode *phi;
    86   // Check for tight loop increments: Loop-phi of Add of loop-phi
    87   if( in1->is_Phi() && (phi = in1->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add)
    88     return false;
    89   if( in2->is_Phi() && (phi = in2->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add){
    90     add->swap_edges(1, 2);
    91     return true;
    92   }
    94   // Otherwise, sort inputs (commutativity) to help value numbering.
    95   if( in1->_idx > in2->_idx ) {
    96     add->swap_edges(1, 2);
    97     return true;
    98   }
    99   return false;
   100 }
   102 //------------------------------Idealize---------------------------------------
   103 // If we get here, we assume we are associative!
   104 Node *AddNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   105   const Type *t1 = phase->type( in(1) );
   106   const Type *t2 = phase->type( in(2) );
   107   int con_left  = t1->singleton();
   108   int con_right = t2->singleton();
   110   // Check for commutative operation desired
   111   if( commute(this,con_left,con_right) ) return this;
   113   AddNode *progress = NULL;             // Progress flag
   115   // Convert "(x+1)+2" into "x+(1+2)".  If the right input is a
   116   // constant, and the left input is an add of a constant, flatten the
   117   // expression tree.
   118   Node *add1 = in(1);
   119   Node *add2 = in(2);
   120   int add1_op = add1->Opcode();
   121   int this_op = Opcode();
   122   if( con_right && t2 != Type::TOP && // Right input is a constant?
   123       add1_op == this_op ) { // Left input is an Add?
   125     // Type of left _in right input
   126     const Type *t12 = phase->type( add1->in(2) );
   127     if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant?
   128       // Check for rare case of closed data cycle which can happen inside
   129       // unreachable loops. In these cases the computation is undefined.
   130 #ifdef ASSERT
   131       Node *add11    = add1->in(1);
   132       int   add11_op = add11->Opcode();
   133       if( (add1 == add1->in(1))
   134          || (add11_op == this_op && add11->in(1) == add1) ) {
   135         assert(false, "dead loop in AddNode::Ideal");
   136       }
   137 #endif
   138       // The Add of the flattened expression
   139       Node *x1 = add1->in(1);
   140       Node *x2 = phase->makecon( add1->as_Add()->add_ring( t2, t12 ));
   141       PhaseIterGVN *igvn = phase->is_IterGVN();
   142       if( igvn ) {
   143         set_req_X(2,x2,igvn);
   144         set_req_X(1,x1,igvn);
   145       } else {
   146         set_req(2,x2);
   147         set_req(1,x1);
   148       }
   149       progress = this;            // Made progress
   150       add1 = in(1);
   151       add1_op = add1->Opcode();
   152     }
   153   }
   155   // Convert "(x+1)+y" into "(x+y)+1".  Push constants down the expression tree.
   156   if( add1_op == this_op && !con_right ) {
   157     Node *a12 = add1->in(2);
   158     const Type *t12 = phase->type( a12 );
   159     if( t12->singleton() && t12 != Type::TOP && (add1 != add1->in(1)) &&
   160        !(add1->in(1)->is_Phi() && add1->in(1)->as_Phi()->is_tripcount()) ) {
   161       assert(add1->in(1) != this, "dead loop in AddNode::Ideal");
   162       add2 = add1->clone();
   163       add2->set_req(2, in(2));
   164       add2 = phase->transform(add2);
   165       set_req(1, add2);
   166       set_req(2, a12);
   167       progress = this;
   168       add2 = a12;
   169     }
   170   }
   172   // Convert "x+(y+1)" into "(x+y)+1".  Push constants down the expression tree.
   173   int add2_op = add2->Opcode();
   174   if( add2_op == this_op && !con_left ) {
   175     Node *a22 = add2->in(2);
   176     const Type *t22 = phase->type( a22 );
   177     if( t22->singleton() && t22 != Type::TOP && (add2 != add2->in(1)) &&
   178        !(add2->in(1)->is_Phi() && add2->in(1)->as_Phi()->is_tripcount()) ) {
   179       assert(add2->in(1) != this, "dead loop in AddNode::Ideal");
   180       Node *addx = add2->clone();
   181       addx->set_req(1, in(1));
   182       addx->set_req(2, add2->in(1));
   183       addx = phase->transform(addx);
   184       set_req(1, addx);
   185       set_req(2, a22);
   186       progress = this;
   187     }
   188   }
   190   return progress;
   191 }
   193 //------------------------------Value-----------------------------------------
   194 // An add node sums it's two _in.  If one input is an RSD, we must mixin
   195 // the other input's symbols.
   196 const Type *AddNode::Value( PhaseTransform *phase ) const {
   197   // Either input is TOP ==> the result is TOP
   198   const Type *t1 = phase->type( in(1) );
   199   const Type *t2 = phase->type( in(2) );
   200   if( t1 == Type::TOP ) return Type::TOP;
   201   if( t2 == Type::TOP ) return Type::TOP;
   203   // Either input is BOTTOM ==> the result is the local BOTTOM
   204   const Type *bot = bottom_type();
   205   if( (t1 == bot) || (t2 == bot) ||
   206       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
   207     return bot;
   209   // Check for an addition involving the additive identity
   210   const Type *tadd = add_of_identity( t1, t2 );
   211   if( tadd ) return tadd;
   213   return add_ring(t1,t2);               // Local flavor of type addition
   214 }
   216 //------------------------------add_identity-----------------------------------
   217 // Check for addition of the identity
   218 const Type *AddNode::add_of_identity( const Type *t1, const Type *t2 ) const {
   219   const Type *zero = add_id();  // The additive identity
   220   if( t1->higher_equal( zero ) ) return t2;
   221   if( t2->higher_equal( zero ) ) return t1;
   223   return NULL;
   224 }
   227 //=============================================================================
   228 //------------------------------Idealize---------------------------------------
   229 Node *AddINode::Ideal(PhaseGVN *phase, bool can_reshape) {
   230   Node* in1 = in(1);
   231   Node* in2 = in(2);
   232   int op1 = in1->Opcode();
   233   int op2 = in2->Opcode();
   234   // Fold (con1-x)+con2 into (con1+con2)-x
   235   if ( op1 == Op_AddI && op2 == Op_SubI ) {
   236     // Swap edges to try optimizations below
   237     in1 = in2;
   238     in2 = in(1);
   239     op1 = op2;
   240     op2 = in2->Opcode();
   241   }
   242   if( op1 == Op_SubI ) {
   243     const Type *t_sub1 = phase->type( in1->in(1) );
   244     const Type *t_2    = phase->type( in2        );
   245     if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
   246       return new (phase->C, 3) SubINode(phase->makecon( add_ring( t_sub1, t_2 ) ),
   247                               in1->in(2) );
   248     // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
   249     if( op2 == Op_SubI ) {
   250       // Check for dead cycle: d = (a-b)+(c-d)
   251       assert( in1->in(2) != this && in2->in(2) != this,
   252               "dead loop in AddINode::Ideal" );
   253       Node *sub  = new (phase->C, 3) SubINode(NULL, NULL);
   254       sub->init_req(1, phase->transform(new (phase->C, 3) AddINode(in1->in(1), in2->in(1) ) ));
   255       sub->init_req(2, phase->transform(new (phase->C, 3) AddINode(in1->in(2), in2->in(2) ) ));
   256       return sub;
   257     }
   258     // Convert "(a-b)+(b+c)" into "(a+c)"
   259     if( op2 == Op_AddI && in1->in(2) == in2->in(1) ) {
   260       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal");
   261       return new (phase->C, 3) AddINode(in1->in(1), in2->in(2));
   262     }
   263     // Convert "(a-b)+(c+b)" into "(a+c)"
   264     if( op2 == Op_AddI && in1->in(2) == in2->in(2) ) {
   265       assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddINode::Ideal");
   266       return new (phase->C, 3) AddINode(in1->in(1), in2->in(1));
   267     }
   268     // Convert "(a-b)+(b-c)" into "(a-c)"
   269     if( op2 == Op_SubI && in1->in(2) == in2->in(1) ) {
   270       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal");
   271       return new (phase->C, 3) SubINode(in1->in(1), in2->in(2));
   272     }
   273     // Convert "(a-b)+(c-a)" into "(c-b)"
   274     if( op2 == Op_SubI && in1->in(1) == in2->in(2) ) {
   275       assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddINode::Ideal");
   276       return new (phase->C, 3) SubINode(in2->in(1), in1->in(2));
   277     }
   278   }
   280   // Convert "x+(0-y)" into "(x-y)"
   281   if( op2 == Op_SubI && phase->type(in2->in(1)) == TypeInt::ZERO )
   282     return new (phase->C, 3) SubINode(in1, in2->in(2) );
   284   // Convert "(0-y)+x" into "(x-y)"
   285   if( op1 == Op_SubI && phase->type(in1->in(1)) == TypeInt::ZERO )
   286     return new (phase->C, 3) SubINode( in2, in1->in(2) );
   288   // Convert (x>>>z)+y into (x+(y<<z))>>>z for small constant z and y.
   289   // Helps with array allocation math constant folding
   290   // See 4790063:
   291   // Unrestricted transformation is unsafe for some runtime values of 'x'
   292   // ( x ==  0, z == 1, y == -1 ) fails
   293   // ( x == -5, z == 1, y ==  1 ) fails
   294   // Transform works for small z and small negative y when the addition
   295   // (x + (y << z)) does not cross zero.
   296   // Implement support for negative y and (x >= -(y << z))
   297   // Have not observed cases where type information exists to support
   298   // positive y and (x <= -(y << z))
   299   if( op1 == Op_URShiftI && op2 == Op_ConI &&
   300       in1->in(2)->Opcode() == Op_ConI ) {
   301     jint z = phase->type( in1->in(2) )->is_int()->get_con() & 0x1f; // only least significant 5 bits matter
   302     jint y = phase->type( in2 )->is_int()->get_con();
   304     if( z < 5 && -5 < y && y < 0 ) {
   305       const Type *t_in11 = phase->type(in1->in(1));
   306       if( t_in11 != Type::TOP && (t_in11->is_int()->_lo >= -(y << z)) ) {
   307         Node *a = phase->transform( new (phase->C, 3) AddINode( in1->in(1), phase->intcon(y<<z) ) );
   308         return new (phase->C, 3) URShiftINode( a, in1->in(2) );
   309       }
   310     }
   311   }
   313   return AddNode::Ideal(phase, can_reshape);
   314 }
   317 //------------------------------Identity---------------------------------------
   318 // Fold (x-y)+y  OR  y+(x-y)  into  x
   319 Node *AddINode::Identity( PhaseTransform *phase ) {
   320   if( in(1)->Opcode() == Op_SubI && phase->eqv(in(1)->in(2),in(2)) ) {
   321     return in(1)->in(1);
   322   }
   323   else if( in(2)->Opcode() == Op_SubI && phase->eqv(in(2)->in(2),in(1)) ) {
   324     return in(2)->in(1);
   325   }
   326   return AddNode::Identity(phase);
   327 }
   330 //------------------------------add_ring---------------------------------------
   331 // Supplied function returns the sum of the inputs.  Guaranteed never
   332 // to be passed a TOP or BOTTOM type, these are filtered out by
   333 // pre-check.
   334 const Type *AddINode::add_ring( const Type *t0, const Type *t1 ) const {
   335   const TypeInt *r0 = t0->is_int(); // Handy access
   336   const TypeInt *r1 = t1->is_int();
   337   int lo = r0->_lo + r1->_lo;
   338   int hi = r0->_hi + r1->_hi;
   339   if( !(r0->is_con() && r1->is_con()) ) {
   340     // Not both constants, compute approximate result
   341     if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
   342       lo = min_jint; hi = max_jint; // Underflow on the low side
   343     }
   344     if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
   345       lo = min_jint; hi = max_jint; // Overflow on the high side
   346     }
   347     if( lo > hi ) {               // Handle overflow
   348       lo = min_jint; hi = max_jint;
   349     }
   350   } else {
   351     // both constants, compute precise result using 'lo' and 'hi'
   352     // Semantics define overflow and underflow for integer addition
   353     // as expected.  In particular: 0x80000000 + 0x80000000 --> 0x0
   354   }
   355   return TypeInt::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
   356 }
   359 //=============================================================================
   360 //------------------------------Idealize---------------------------------------
   361 Node *AddLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   362   Node* in1 = in(1);
   363   Node* in2 = in(2);
   364   int op1 = in1->Opcode();
   365   int op2 = in2->Opcode();
   366   // Fold (con1-x)+con2 into (con1+con2)-x
   367   if ( op1 == Op_AddL && op2 == Op_SubL ) {
   368     // Swap edges to try optimizations below
   369     in1 = in2;
   370     in2 = in(1);
   371     op1 = op2;
   372     op2 = in2->Opcode();
   373   }
   374   // Fold (con1-x)+con2 into (con1+con2)-x
   375   if( op1 == Op_SubL ) {
   376     const Type *t_sub1 = phase->type( in1->in(1) );
   377     const Type *t_2    = phase->type( in2        );
   378     if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
   379       return new (phase->C, 3) SubLNode(phase->makecon( add_ring( t_sub1, t_2 ) ),
   380                               in1->in(2) );
   381     // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
   382     if( op2 == Op_SubL ) {
   383       // Check for dead cycle: d = (a-b)+(c-d)
   384       assert( in1->in(2) != this && in2->in(2) != this,
   385               "dead loop in AddLNode::Ideal" );
   386       Node *sub  = new (phase->C, 3) SubLNode(NULL, NULL);
   387       sub->init_req(1, phase->transform(new (phase->C, 3) AddLNode(in1->in(1), in2->in(1) ) ));
   388       sub->init_req(2, phase->transform(new (phase->C, 3) AddLNode(in1->in(2), in2->in(2) ) ));
   389       return sub;
   390     }
   391     // Convert "(a-b)+(b+c)" into "(a+c)"
   392     if( op2 == Op_AddL && in1->in(2) == in2->in(1) ) {
   393       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal");
   394       return new (phase->C, 3) AddLNode(in1->in(1), in2->in(2));
   395     }
   396     // Convert "(a-b)+(c+b)" into "(a+c)"
   397     if( op2 == Op_AddL && in1->in(2) == in2->in(2) ) {
   398       assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal");
   399       return new (phase->C, 3) AddLNode(in1->in(1), in2->in(1));
   400     }
   401     // Convert "(a-b)+(b-c)" into "(a-c)"
   402     if( op2 == Op_SubL && in1->in(2) == in2->in(1) ) {
   403       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal");
   404       return new (phase->C, 3) SubLNode(in1->in(1), in2->in(2));
   405     }
   406     // Convert "(a-b)+(c-a)" into "(c-b)"
   407     if( op2 == Op_SubL && in1->in(1) == in1->in(2) ) {
   408       assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal");
   409       return new (phase->C, 3) SubLNode(in2->in(1), in1->in(2));
   410     }
   411   }
   413   // Convert "x+(0-y)" into "(x-y)"
   414   if( op2 == Op_SubL && phase->type(in2->in(1)) == TypeLong::ZERO )
   415     return new (phase->C, 3) SubLNode( in1, in2->in(2) );
   417   // Convert "(0-y)+x" into "(x-y)"
   418   if( op1 == Op_SubL && phase->type(in1->in(1)) == TypeInt::ZERO )
   419     return new (phase->C, 3) SubLNode( in2, in1->in(2) );
   421   // Convert "X+X+X+X+X...+X+Y" into "k*X+Y" or really convert "X+(X+Y)"
   422   // into "(X<<1)+Y" and let shift-folding happen.
   423   if( op2 == Op_AddL &&
   424       in2->in(1) == in1 &&
   425       op1 != Op_ConL &&
   426       0 ) {
   427     Node *shift = phase->transform(new (phase->C, 3) LShiftLNode(in1,phase->intcon(1)));
   428     return new (phase->C, 3) AddLNode(shift,in2->in(2));
   429   }
   431   return AddNode::Ideal(phase, can_reshape);
   432 }
   435 //------------------------------Identity---------------------------------------
   436 // Fold (x-y)+y  OR  y+(x-y)  into  x
   437 Node *AddLNode::Identity( PhaseTransform *phase ) {
   438   if( in(1)->Opcode() == Op_SubL && phase->eqv(in(1)->in(2),in(2)) ) {
   439     return in(1)->in(1);
   440   }
   441   else if( in(2)->Opcode() == Op_SubL && phase->eqv(in(2)->in(2),in(1)) ) {
   442     return in(2)->in(1);
   443   }
   444   return AddNode::Identity(phase);
   445 }
   448 //------------------------------add_ring---------------------------------------
   449 // Supplied function returns the sum of the inputs.  Guaranteed never
   450 // to be passed a TOP or BOTTOM type, these are filtered out by
   451 // pre-check.
   452 const Type *AddLNode::add_ring( const Type *t0, const Type *t1 ) const {
   453   const TypeLong *r0 = t0->is_long(); // Handy access
   454   const TypeLong *r1 = t1->is_long();
   455   jlong lo = r0->_lo + r1->_lo;
   456   jlong hi = r0->_hi + r1->_hi;
   457   if( !(r0->is_con() && r1->is_con()) ) {
   458     // Not both constants, compute approximate result
   459     if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
   460       lo =min_jlong; hi = max_jlong; // Underflow on the low side
   461     }
   462     if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
   463       lo = min_jlong; hi = max_jlong; // Overflow on the high side
   464     }
   465     if( lo > hi ) {               // Handle overflow
   466       lo = min_jlong; hi = max_jlong;
   467     }
   468   } else {
   469     // both constants, compute precise result using 'lo' and 'hi'
   470     // Semantics define overflow and underflow for integer addition
   471     // as expected.  In particular: 0x80000000 + 0x80000000 --> 0x0
   472   }
   473   return TypeLong::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
   474 }
   477 //=============================================================================
   478 //------------------------------add_of_identity--------------------------------
   479 // Check for addition of the identity
   480 const Type *AddFNode::add_of_identity( const Type *t1, const Type *t2 ) const {
   481   // x ADD 0  should return x unless 'x' is a -zero
   482   //
   483   // const Type *zero = add_id();     // The additive identity
   484   // jfloat f1 = t1->getf();
   485   // jfloat f2 = t2->getf();
   486   //
   487   // if( t1->higher_equal( zero ) ) return t2;
   488   // if( t2->higher_equal( zero ) ) return t1;
   490   return NULL;
   491 }
   493 //------------------------------add_ring---------------------------------------
   494 // Supplied function returns the sum of the inputs.
   495 // This also type-checks the inputs for sanity.  Guaranteed never to
   496 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
   497 const Type *AddFNode::add_ring( const Type *t0, const Type *t1 ) const {
   498   // We must be adding 2 float constants.
   499   return TypeF::make( t0->getf() + t1->getf() );
   500 }
   502 //------------------------------Ideal------------------------------------------
   503 Node *AddFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   504   if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
   505     return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
   506   }
   508   // Floating point additions are not associative because of boundary conditions (infinity)
   509   return commute(this,
   510                  phase->type( in(1) )->singleton(),
   511                  phase->type( in(2) )->singleton() ) ? this : NULL;
   512 }
   515 //=============================================================================
   516 //------------------------------add_of_identity--------------------------------
   517 // Check for addition of the identity
   518 const Type *AddDNode::add_of_identity( const Type *t1, const Type *t2 ) const {
   519   // x ADD 0  should return x unless 'x' is a -zero
   520   //
   521   // const Type *zero = add_id();     // The additive identity
   522   // jfloat f1 = t1->getf();
   523   // jfloat f2 = t2->getf();
   524   //
   525   // if( t1->higher_equal( zero ) ) return t2;
   526   // if( t2->higher_equal( zero ) ) return t1;
   528   return NULL;
   529 }
   530 //------------------------------add_ring---------------------------------------
   531 // Supplied function returns the sum of the inputs.
   532 // This also type-checks the inputs for sanity.  Guaranteed never to
   533 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
   534 const Type *AddDNode::add_ring( const Type *t0, const Type *t1 ) const {
   535   // We must be adding 2 double constants.
   536   return TypeD::make( t0->getd() + t1->getd() );
   537 }
   539 //------------------------------Ideal------------------------------------------
   540 Node *AddDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   541   if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
   542     return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
   543   }
   545   // Floating point additions are not associative because of boundary conditions (infinity)
   546   return commute(this,
   547                  phase->type( in(1) )->singleton(),
   548                  phase->type( in(2) )->singleton() ) ? this : NULL;
   549 }
   552 //=============================================================================
   553 //------------------------------Identity---------------------------------------
   554 // If one input is a constant 0, return the other input.
   555 Node *AddPNode::Identity( PhaseTransform *phase ) {
   556   return ( phase->type( in(Offset) )->higher_equal( TypeX_ZERO ) ) ? in(Address) : this;
   557 }
   559 //------------------------------Idealize---------------------------------------
   560 Node *AddPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   561   // Bail out if dead inputs
   562   if( phase->type( in(Address) ) == Type::TOP ) return NULL;
   564   // If the left input is an add of a constant, flatten the expression tree.
   565   const Node *n = in(Address);
   566   if (n->is_AddP() && n->in(Base) == in(Base)) {
   567     const AddPNode *addp = n->as_AddP(); // Left input is an AddP
   568     assert( !addp->in(Address)->is_AddP() ||
   569              addp->in(Address)->as_AddP() != addp,
   570             "dead loop in AddPNode::Ideal" );
   571     // Type of left input's right input
   572     const Type *t = phase->type( addp->in(Offset) );
   573     if( t == Type::TOP ) return NULL;
   574     const TypeX *t12 = t->is_intptr_t();
   575     if( t12->is_con() ) {       // Left input is an add of a constant?
   576       // If the right input is a constant, combine constants
   577       const Type *temp_t2 = phase->type( in(Offset) );
   578       if( temp_t2 == Type::TOP ) return NULL;
   579       const TypeX *t2 = temp_t2->is_intptr_t();
   580       Node* address;
   581       Node* offset;
   582       if( t2->is_con() ) {
   583         // The Add of the flattened expression
   584         address = addp->in(Address);
   585         offset  = phase->MakeConX(t2->get_con() + t12->get_con());
   586       } else {
   587         // Else move the constant to the right.  ((A+con)+B) into ((A+B)+con)
   588         address = phase->transform(new (phase->C, 4) AddPNode(in(Base),addp->in(Address),in(Offset)));
   589         offset  = addp->in(Offset);
   590       }
   591       PhaseIterGVN *igvn = phase->is_IterGVN();
   592       if( igvn ) {
   593         set_req_X(Address,address,igvn);
   594         set_req_X(Offset,offset,igvn);
   595       } else {
   596         set_req(Address,address);
   597         set_req(Offset,offset);
   598       }
   599       return this;
   600     }
   601   }
   603   // Raw pointers?
   604   if( in(Base)->bottom_type() == Type::TOP ) {
   605     // If this is a NULL+long form (from unsafe accesses), switch to a rawptr.
   606     if (phase->type(in(Address)) == TypePtr::NULL_PTR) {
   607       Node* offset = in(Offset);
   608       return new (phase->C, 2) CastX2PNode(offset);
   609     }
   610   }
   612   // If the right is an add of a constant, push the offset down.
   613   // Convert: (ptr + (offset+con)) into (ptr+offset)+con.
   614   // The idea is to merge array_base+scaled_index groups together,
   615   // and only have different constant offsets from the same base.
   616   const Node *add = in(Offset);
   617   if( add->Opcode() == Op_AddX && add->in(1) != add ) {
   618     const Type *t22 = phase->type( add->in(2) );
   619     if( t22->singleton() && (t22 != Type::TOP) ) {  // Right input is an add of a constant?
   620       set_req(Address, phase->transform(new (phase->C, 4) AddPNode(in(Base),in(Address),add->in(1))));
   621       set_req(Offset, add->in(2));
   622       return this;              // Made progress
   623     }
   624   }
   626   return NULL;                  // No progress
   627 }
   629 //------------------------------bottom_type------------------------------------
   630 // Bottom-type is the pointer-type with unknown offset.
   631 const Type *AddPNode::bottom_type() const {
   632   if (in(Address) == NULL)  return TypePtr::BOTTOM;
   633   const TypePtr *tp = in(Address)->bottom_type()->isa_ptr();
   634   if( !tp ) return Type::TOP;   // TOP input means TOP output
   635   assert( in(Offset)->Opcode() != Op_ConP, "" );
   636   const Type *t = in(Offset)->bottom_type();
   637   if( t == Type::TOP )
   638     return tp->add_offset(Type::OffsetTop);
   639   const TypeX *tx = t->is_intptr_t();
   640   intptr_t txoffset = Type::OffsetBot;
   641   if (tx->is_con()) {   // Left input is an add of a constant?
   642     txoffset = tx->get_con();
   643   }
   644   return tp->add_offset(txoffset);
   645 }
   647 //------------------------------Value------------------------------------------
   648 const Type *AddPNode::Value( PhaseTransform *phase ) const {
   649   // Either input is TOP ==> the result is TOP
   650   const Type *t1 = phase->type( in(Address) );
   651   const Type *t2 = phase->type( in(Offset) );
   652   if( t1 == Type::TOP ) return Type::TOP;
   653   if( t2 == Type::TOP ) return Type::TOP;
   655   // Left input is a pointer
   656   const TypePtr *p1 = t1->isa_ptr();
   657   // Right input is an int
   658   const TypeX *p2 = t2->is_intptr_t();
   659   // Add 'em
   660   intptr_t p2offset = Type::OffsetBot;
   661   if (p2->is_con()) {   // Left input is an add of a constant?
   662     p2offset = p2->get_con();
   663   }
   664   return p1->add_offset(p2offset);
   665 }
   667 //------------------------Ideal_base_and_offset--------------------------------
   668 // Split an oop pointer into a base and offset.
   669 // (The offset might be Type::OffsetBot in the case of an array.)
   670 // Return the base, or NULL if failure.
   671 Node* AddPNode::Ideal_base_and_offset(Node* ptr, PhaseTransform* phase,
   672                                       // second return value:
   673                                       intptr_t& offset) {
   674   if (ptr->is_AddP()) {
   675     Node* base = ptr->in(AddPNode::Base);
   676     Node* addr = ptr->in(AddPNode::Address);
   677     Node* offs = ptr->in(AddPNode::Offset);
   678     if (base == addr || base->is_top()) {
   679       offset = phase->find_intptr_t_con(offs, Type::OffsetBot);
   680       if (offset != Type::OffsetBot) {
   681         return addr;
   682       }
   683     }
   684   }
   685   offset = Type::OffsetBot;
   686   return NULL;
   687 }
   689 //------------------------------unpack_offsets----------------------------------
   690 // Collect the AddP offset values into the elements array, giving up
   691 // if there are more than length.
   692 int AddPNode::unpack_offsets(Node* elements[], int length) {
   693   int count = 0;
   694   Node* addr = this;
   695   Node* base = addr->in(AddPNode::Base);
   696   while (addr->is_AddP()) {
   697     if (addr->in(AddPNode::Base) != base) {
   698       // give up
   699       return -1;
   700     }
   701     elements[count++] = addr->in(AddPNode::Offset);
   702     if (count == length) {
   703       // give up
   704       return -1;
   705     }
   706     addr = addr->in(AddPNode::Address);
   707   }
   708   return count;
   709 }
   711 //------------------------------match_edge-------------------------------------
   712 // Do we Match on this edge index or not?  Do not match base pointer edge
   713 uint AddPNode::match_edge(uint idx) const {
   714   return idx > Base;
   715 }
   717 //---------------------------mach_bottom_type----------------------------------
   718 // Utility function for use by ADLC.  Implements bottom_type for matched AddP.
   719 const Type *AddPNode::mach_bottom_type( const MachNode* n) {
   720   Node* base = n->in(Base);
   721   const Type *t = base->bottom_type();
   722   if ( t == Type::TOP ) {
   723     // an untyped pointer
   724     return TypeRawPtr::BOTTOM;
   725   }
   726   const TypePtr* tp = t->isa_oopptr();
   727   if ( tp == NULL )  return t;
   728   if ( tp->_offset == TypePtr::OffsetBot )  return tp;
   730   // We must carefully add up the various offsets...
   731   intptr_t offset = 0;
   732   const TypePtr* tptr = NULL;
   734   uint numopnds = n->num_opnds();
   735   uint index = n->oper_input_base();
   736   for ( uint i = 1; i < numopnds; i++ ) {
   737     MachOper *opnd = n->_opnds[i];
   738     // Check for any interesting operand info.
   739     // In particular, check for both memory and non-memory operands.
   740     // %%%%% Clean this up: use xadd_offset
   741     intptr_t con = opnd->constant();
   742     if ( con == TypePtr::OffsetBot )  goto bottom_out;
   743     offset += con;
   744     con = opnd->constant_disp();
   745     if ( con == TypePtr::OffsetBot )  goto bottom_out;
   746     offset += con;
   747     if( opnd->scale() != 0 ) goto bottom_out;
   749     // Check each operand input edge.  Find the 1 allowed pointer
   750     // edge.  Other edges must be index edges; track exact constant
   751     // inputs and otherwise assume the worst.
   752     for ( uint j = opnd->num_edges(); j > 0; j-- ) {
   753       Node* edge = n->in(index++);
   754       const Type*    et  = edge->bottom_type();
   755       const TypeX*   eti = et->isa_intptr_t();
   756       if ( eti == NULL ) {
   757         // there must be one pointer among the operands
   758         guarantee(tptr == NULL, "must be only one pointer operand");
   759         if (UseCompressedOops && Universe::narrow_oop_shift() == 0) {
   760           // 32-bits narrow oop can be the base of address expressions
   761           tptr = et->make_ptr()->isa_oopptr();
   762         } else {
   763           // only regular oops are expected here
   764           tptr = et->isa_oopptr();
   765         }
   766         guarantee(tptr != NULL, "non-int operand must be pointer");
   767         if (tptr->higher_equal(tp->add_offset(tptr->offset())))
   768           tp = tptr; // Set more precise type for bailout
   769         continue;
   770       }
   771       if ( eti->_hi != eti->_lo )  goto bottom_out;
   772       offset += eti->_lo;
   773     }
   774   }
   775   guarantee(tptr != NULL, "must be exactly one pointer operand");
   776   return tptr->add_offset(offset);
   778  bottom_out:
   779   return tp->add_offset(TypePtr::OffsetBot);
   780 }
   782 //=============================================================================
   783 //------------------------------Identity---------------------------------------
   784 Node *OrINode::Identity( PhaseTransform *phase ) {
   785   // x | x => x
   786   if (phase->eqv(in(1), in(2))) {
   787     return in(1);
   788   }
   790   return AddNode::Identity(phase);
   791 }
   793 //------------------------------add_ring---------------------------------------
   794 // Supplied function returns the sum of the inputs IN THE CURRENT RING.  For
   795 // the logical operations the ring's ADD is really a logical OR function.
   796 // This also type-checks the inputs for sanity.  Guaranteed never to
   797 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
   798 const Type *OrINode::add_ring( const Type *t0, const Type *t1 ) const {
   799   const TypeInt *r0 = t0->is_int(); // Handy access
   800   const TypeInt *r1 = t1->is_int();
   802   // If both args are bool, can figure out better types
   803   if ( r0 == TypeInt::BOOL ) {
   804     if ( r1 == TypeInt::ONE) {
   805       return TypeInt::ONE;
   806     } else if ( r1 == TypeInt::BOOL ) {
   807       return TypeInt::BOOL;
   808     }
   809   } else if ( r0 == TypeInt::ONE ) {
   810     if ( r1 == TypeInt::BOOL ) {
   811       return TypeInt::ONE;
   812     }
   813   }
   815   // If either input is not a constant, just return all integers.
   816   if( !r0->is_con() || !r1->is_con() )
   817     return TypeInt::INT;        // Any integer, but still no symbols.
   819   // Otherwise just OR them bits.
   820   return TypeInt::make( r0->get_con() | r1->get_con() );
   821 }
   823 //=============================================================================
   824 //------------------------------Identity---------------------------------------
   825 Node *OrLNode::Identity( PhaseTransform *phase ) {
   826   // x | x => x
   827   if (phase->eqv(in(1), in(2))) {
   828     return in(1);
   829   }
   831   return AddNode::Identity(phase);
   832 }
   834 //------------------------------add_ring---------------------------------------
   835 const Type *OrLNode::add_ring( const Type *t0, const Type *t1 ) const {
   836   const TypeLong *r0 = t0->is_long(); // Handy access
   837   const TypeLong *r1 = t1->is_long();
   839   // If either input is not a constant, just return all integers.
   840   if( !r0->is_con() || !r1->is_con() )
   841     return TypeLong::LONG;      // Any integer, but still no symbols.
   843   // Otherwise just OR them bits.
   844   return TypeLong::make( r0->get_con() | r1->get_con() );
   845 }
   847 //=============================================================================
   848 //------------------------------add_ring---------------------------------------
   849 // Supplied function returns the sum of the inputs IN THE CURRENT RING.  For
   850 // the logical operations the ring's ADD is really a logical OR function.
   851 // This also type-checks the inputs for sanity.  Guaranteed never to
   852 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
   853 const Type *XorINode::add_ring( const Type *t0, const Type *t1 ) const {
   854   const TypeInt *r0 = t0->is_int(); // Handy access
   855   const TypeInt *r1 = t1->is_int();
   857   // Complementing a boolean?
   858   if( r0 == TypeInt::BOOL && ( r1 == TypeInt::ONE
   859                                || r1 == TypeInt::BOOL))
   860     return TypeInt::BOOL;
   862   if( !r0->is_con() || !r1->is_con() ) // Not constants
   863     return TypeInt::INT;        // Any integer, but still no symbols.
   865   // Otherwise just XOR them bits.
   866   return TypeInt::make( r0->get_con() ^ r1->get_con() );
   867 }
   869 //=============================================================================
   870 //------------------------------add_ring---------------------------------------
   871 const Type *XorLNode::add_ring( const Type *t0, const Type *t1 ) const {
   872   const TypeLong *r0 = t0->is_long(); // Handy access
   873   const TypeLong *r1 = t1->is_long();
   875   // If either input is not a constant, just return all integers.
   876   if( !r0->is_con() || !r1->is_con() )
   877     return TypeLong::LONG;      // Any integer, but still no symbols.
   879   // Otherwise just OR them bits.
   880   return TypeLong::make( r0->get_con() ^ r1->get_con() );
   881 }
   883 //=============================================================================
   884 //------------------------------add_ring---------------------------------------
   885 // Supplied function returns the sum of the inputs.
   886 const Type *MaxINode::add_ring( const Type *t0, const Type *t1 ) const {
   887   const TypeInt *r0 = t0->is_int(); // Handy access
   888   const TypeInt *r1 = t1->is_int();
   890   // Otherwise just MAX them bits.
   891   return TypeInt::make( MAX2(r0->_lo,r1->_lo), MAX2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
   892 }
   894 //=============================================================================
   895 //------------------------------Idealize---------------------------------------
   896 // MINs show up in range-check loop limit calculations.  Look for
   897 // "MIN2(x+c0,MIN2(y,x+c1))".  Pick the smaller constant: "MIN2(x+c0,y)"
   898 Node *MinINode::Ideal(PhaseGVN *phase, bool can_reshape) {
   899   Node *progress = NULL;
   900   // Force a right-spline graph
   901   Node *l = in(1);
   902   Node *r = in(2);
   903   // Transform  MinI1( MinI2(a,b), c)  into  MinI1( a, MinI2(b,c) )
   904   // to force a right-spline graph for the rest of MinINode::Ideal().
   905   if( l->Opcode() == Op_MinI ) {
   906     assert( l != l->in(1), "dead loop in MinINode::Ideal" );
   907     r = phase->transform(new (phase->C, 3) MinINode(l->in(2),r));
   908     l = l->in(1);
   909     set_req(1, l);
   910     set_req(2, r);
   911     return this;
   912   }
   914   // Get left input & constant
   915   Node *x = l;
   916   int x_off = 0;
   917   if( x->Opcode() == Op_AddI && // Check for "x+c0" and collect constant
   918       x->in(2)->is_Con() ) {
   919     const Type *t = x->in(2)->bottom_type();
   920     if( t == Type::TOP ) return NULL;  // No progress
   921     x_off = t->is_int()->get_con();
   922     x = x->in(1);
   923   }
   925   // Scan a right-spline-tree for MINs
   926   Node *y = r;
   927   int y_off = 0;
   928   // Check final part of MIN tree
   929   if( y->Opcode() == Op_AddI && // Check for "y+c1" and collect constant
   930       y->in(2)->is_Con() ) {
   931     const Type *t = y->in(2)->bottom_type();
   932     if( t == Type::TOP ) return NULL;  // No progress
   933     y_off = t->is_int()->get_con();
   934     y = y->in(1);
   935   }
   936   if( x->_idx > y->_idx && r->Opcode() != Op_MinI ) {
   937     swap_edges(1, 2);
   938     return this;
   939   }
   942   if( r->Opcode() == Op_MinI ) {
   943     assert( r != r->in(2), "dead loop in MinINode::Ideal" );
   944     y = r->in(1);
   945     // Check final part of MIN tree
   946     if( y->Opcode() == Op_AddI &&// Check for "y+c1" and collect constant
   947         y->in(2)->is_Con() ) {
   948       const Type *t = y->in(2)->bottom_type();
   949       if( t == Type::TOP ) return NULL;  // No progress
   950       y_off = t->is_int()->get_con();
   951       y = y->in(1);
   952     }
   954     if( x->_idx > y->_idx )
   955       return new (phase->C, 3) MinINode(r->in(1),phase->transform(new (phase->C, 3) MinINode(l,r->in(2))));
   957     // See if covers: MIN2(x+c0,MIN2(y+c1,z))
   958     if( !phase->eqv(x,y) ) return NULL;
   959     // If (y == x) transform MIN2(x+c0, MIN2(x+c1,z)) into
   960     // MIN2(x+c0 or x+c1 which less, z).
   961     return new (phase->C, 3) MinINode(phase->transform(new (phase->C, 3) AddINode(x,phase->intcon(MIN2(x_off,y_off)))),r->in(2));
   962   } else {
   963     // See if covers: MIN2(x+c0,y+c1)
   964     if( !phase->eqv(x,y) ) return NULL;
   965     // If (y == x) transform MIN2(x+c0,x+c1) into x+c0 or x+c1 which less.
   966     return new (phase->C, 3) AddINode(x,phase->intcon(MIN2(x_off,y_off)));
   967   }
   969 }
   971 //------------------------------add_ring---------------------------------------
   972 // Supplied function returns the sum of the inputs.
   973 const Type *MinINode::add_ring( const Type *t0, const Type *t1 ) const {
   974   const TypeInt *r0 = t0->is_int(); // Handy access
   975   const TypeInt *r1 = t1->is_int();
   977   // Otherwise just MIN them bits.
   978   return TypeInt::make( MIN2(r0->_lo,r1->_lo), MIN2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
   979 }

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