1 /*
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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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24 
25 #include "precompiled.hpp"
26 #include "memory/allocation.inline.hpp"
27 #include "opto/addnode.hpp"
28 #include "opto/castnode.hpp"
29 #include "opto/cfgnode.hpp"
30 #include "opto/connode.hpp"
31 #include "opto/machnode.hpp"
32 #include "opto/mulnode.hpp"
33 #include "opto/phaseX.hpp"
34 #include "opto/subnode.hpp"
35 
36 // Portions of code courtesy of Clifford Click
37 
38 // Classic Add functionality.  This covers all the usual 'add' behaviors for
39 // an algebraic ring.  Add-integer, add-float, add-double, and binary-or are
40 // all inherited from this class.  The various identity values are supplied
41 // by virtual functions.
42 
43 
44 //=============================================================================
45 //------------------------------hash-------------------------------------------
46 // Hash function over AddNodes.  Needs to be commutative; i.e., I swap
47 // (commute) inputs to AddNodes willy-nilly so the hash function must return
48 // the same value in the presence of edge swapping.
hash() const49 uint AddNode::hash() const {
50   return (uintptr_t)in(1) + (uintptr_t)in(2) + Opcode();
51 }
52 
53 //------------------------------Identity---------------------------------------
54 // If either input is a constant 0, return the other input.
Identity(PhaseGVN * phase)55 Node* AddNode::Identity(PhaseGVN* phase) {
56   const Type *zero = add_id();  // The additive identity
57   if( phase->type( in(1) )->higher_equal( zero ) ) return in(2);
58   if( phase->type( in(2) )->higher_equal( zero ) ) return in(1);
59   return this;
60 }
61 
62 //------------------------------commute----------------------------------------
63 // Commute operands to move loads and constants to the right.
commute(Node * add,bool con_left,bool con_right)64 static bool commute(Node *add, bool con_left, bool con_right) {
65   Node *in1 = add->in(1);
66   Node *in2 = add->in(2);
67 
68   // Convert "1+x" into "x+1".
69   // Right is a constant; leave it
70   if( con_right ) return false;
71   // Left is a constant; move it right.
72   if( con_left ) {
73     add->swap_edges(1, 2);
74     return true;
75   }
76 
77   // Convert "Load+x" into "x+Load".
78   // Now check for loads
79   if (in2->is_Load()) {
80     if (!in1->is_Load()) {
81       // already x+Load to return
82       return false;
83     }
84     // both are loads, so fall through to sort inputs by idx
85   } else if( in1->is_Load() ) {
86     // Left is a Load and Right is not; move it right.
87     add->swap_edges(1, 2);
88     return true;
89   }
90 
91   PhiNode *phi;
92   // Check for tight loop increments: Loop-phi of Add of loop-phi
93   if( in1->is_Phi() && (phi = in1->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add)
94     return false;
95   if( in2->is_Phi() && (phi = in2->as_Phi()) && !phi->is_copy() && phi->region()->is_Loop() && phi->in(2)==add){
96     add->swap_edges(1, 2);
97     return true;
98   }
99 
100   // Otherwise, sort inputs (commutativity) to help value numbering.
101   if( in1->_idx > in2->_idx ) {
102     add->swap_edges(1, 2);
103     return true;
104   }
105   return false;
106 }
107 
108 //------------------------------Idealize---------------------------------------
109 // If we get here, we assume we are associative!
Ideal(PhaseGVN * phase,bool can_reshape)110 Node *AddNode::Ideal(PhaseGVN *phase, bool can_reshape) {
111   const Type *t1 = phase->type( in(1) );
112   const Type *t2 = phase->type( in(2) );
113   bool con_left  = t1->singleton();
114   bool con_right = t2->singleton();
115 
116   // Check for commutative operation desired
117   if( commute(this,con_left,con_right) ) return this;
118 
119   AddNode *progress = NULL;             // Progress flag
120 
121   // Convert "(x+1)+2" into "x+(1+2)".  If the right input is a
122   // constant, and the left input is an add of a constant, flatten the
123   // expression tree.
124   Node *add1 = in(1);
125   Node *add2 = in(2);
126   int add1_op = add1->Opcode();
127   int this_op = Opcode();
128   if( con_right && t2 != Type::TOP && // Right input is a constant?
129       add1_op == this_op ) { // Left input is an Add?
130 
131     // Type of left _in right input
132     const Type *t12 = phase->type( add1->in(2) );
133     if( t12->singleton() && t12 != Type::TOP ) { // Left input is an add of a constant?
134       // Check for rare case of closed data cycle which can happen inside
135       // unreachable loops. In these cases the computation is undefined.
136 #ifdef ASSERT
137       Node *add11    = add1->in(1);
138       int   add11_op = add11->Opcode();
139       if( (add1 == add1->in(1))
140          || (add11_op == this_op && add11->in(1) == add1) ) {
141         assert(false, "dead loop in AddNode::Ideal");
142       }
143 #endif
144       // The Add of the flattened expression
145       Node *x1 = add1->in(1);
146       Node *x2 = phase->makecon( add1->as_Add()->add_ring( t2, t12 ));
147       PhaseIterGVN *igvn = phase->is_IterGVN();
148       if( igvn ) {
149         set_req_X(2,x2,igvn);
150         set_req_X(1,x1,igvn);
151       } else {
152         set_req(2,x2);
153         set_req(1,x1);
154       }
155       progress = this;            // Made progress
156       add1 = in(1);
157       add1_op = add1->Opcode();
158     }
159   }
160 
161   // Convert "(x+1)+y" into "(x+y)+1".  Push constants down the expression tree.
162   if( add1_op == this_op && !con_right ) {
163     Node *a12 = add1->in(2);
164     const Type *t12 = phase->type( a12 );
165     if( t12->singleton() && t12 != Type::TOP && (add1 != add1->in(1)) &&
166        !(add1->in(1)->is_Phi() && add1->in(1)->as_Phi()->is_tripcount()) ) {
167       assert(add1->in(1) != this, "dead loop in AddNode::Ideal");
168       add2 = add1->clone();
169       add2->set_req(2, in(2));
170       add2 = phase->transform(add2);
171       set_req(1, add2);
172       set_req(2, a12);
173       progress = this;
174       add2 = a12;
175     }
176   }
177 
178   // Convert "x+(y+1)" into "(x+y)+1".  Push constants down the expression tree.
179   int add2_op = add2->Opcode();
180   if( add2_op == this_op && !con_left ) {
181     Node *a22 = add2->in(2);
182     const Type *t22 = phase->type( a22 );
183     if( t22->singleton() && t22 != Type::TOP && (add2 != add2->in(1)) &&
184        !(add2->in(1)->is_Phi() && add2->in(1)->as_Phi()->is_tripcount()) ) {
185       assert(add2->in(1) != this, "dead loop in AddNode::Ideal");
186       Node *addx = add2->clone();
187       addx->set_req(1, in(1));
188       addx->set_req(2, add2->in(1));
189       addx = phase->transform(addx);
190       set_req(1, addx);
191       set_req(2, a22);
192       progress = this;
193       PhaseIterGVN *igvn = phase->is_IterGVN();
194       if (add2->outcnt() == 0 && igvn) {
195         // add disconnected.
196         igvn->_worklist.push(add2);
197       }
198     }
199   }
200 
201   return progress;
202 }
203 
204 //------------------------------Value-----------------------------------------
205 // An add node sums it's two _in.  If one input is an RSD, we must mixin
206 // the other input's symbols.
Value(PhaseGVN * phase) const207 const Type* AddNode::Value(PhaseGVN* phase) const {
208   // Either input is TOP ==> the result is TOP
209   const Type *t1 = phase->type( in(1) );
210   const Type *t2 = phase->type( in(2) );
211   if( t1 == Type::TOP ) return Type::TOP;
212   if( t2 == Type::TOP ) return Type::TOP;
213 
214   // Either input is BOTTOM ==> the result is the local BOTTOM
215   const Type *bot = bottom_type();
216   if( (t1 == bot) || (t2 == bot) ||
217       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
218     return bot;
219 
220   // Check for an addition involving the additive identity
221   const Type *tadd = add_of_identity( t1, t2 );
222   if( tadd ) return tadd;
223 
224   return add_ring(t1,t2);               // Local flavor of type addition
225 }
226 
227 //------------------------------add_identity-----------------------------------
228 // Check for addition of the identity
add_of_identity(const Type * t1,const Type * t2) const229 const Type *AddNode::add_of_identity( const Type *t1, const Type *t2 ) const {
230   const Type *zero = add_id();  // The additive identity
231   if( t1->higher_equal( zero ) ) return t2;
232   if( t2->higher_equal( zero ) ) return t1;
233 
234   return NULL;
235 }
236 
237 
238 //=============================================================================
239 //------------------------------Idealize---------------------------------------
Ideal(PhaseGVN * phase,bool can_reshape)240 Node *AddINode::Ideal(PhaseGVN *phase, bool can_reshape) {
241   Node* in1 = in(1);
242   Node* in2 = in(2);
243   int op1 = in1->Opcode();
244   int op2 = in2->Opcode();
245   // Fold (con1-x)+con2 into (con1+con2)-x
246   if ( op1 == Op_AddI && op2 == Op_SubI ) {
247     // Swap edges to try optimizations below
248     in1 = in2;
249     in2 = in(1);
250     op1 = op2;
251     op2 = in2->Opcode();
252   }
253   if( op1 == Op_SubI ) {
254     const Type *t_sub1 = phase->type( in1->in(1) );
255     const Type *t_2    = phase->type( in2        );
256     if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
257       return new SubINode(phase->makecon( add_ring( t_sub1, t_2 ) ), in1->in(2) );
258     // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
259     if( op2 == Op_SubI ) {
260       // Check for dead cycle: d = (a-b)+(c-d)
261       assert( in1->in(2) != this && in2->in(2) != this,
262               "dead loop in AddINode::Ideal" );
263       Node *sub  = new SubINode(NULL, NULL);
264       sub->init_req(1, phase->transform(new AddINode(in1->in(1), in2->in(1) ) ));
265       sub->init_req(2, phase->transform(new AddINode(in1->in(2), in2->in(2) ) ));
266       return sub;
267     }
268     // Convert "(a-b)+(b+c)" into "(a+c)"
269     if( op2 == Op_AddI && in1->in(2) == in2->in(1) ) {
270       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal");
271       return new AddINode(in1->in(1), in2->in(2));
272     }
273     // Convert "(a-b)+(c+b)" into "(a+c)"
274     if( op2 == Op_AddI && in1->in(2) == in2->in(2) ) {
275       assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddINode::Ideal");
276       return new AddINode(in1->in(1), in2->in(1));
277     }
278     // Convert "(a-b)+(b-c)" into "(a-c)"
279     if( op2 == Op_SubI && in1->in(2) == in2->in(1) ) {
280       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddINode::Ideal");
281       return new SubINode(in1->in(1), in2->in(2));
282     }
283     // Convert "(a-b)+(c-a)" into "(c-b)"
284     if( op2 == Op_SubI && in1->in(1) == in2->in(2) ) {
285       assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddINode::Ideal");
286       return new SubINode(in2->in(1), in1->in(2));
287     }
288   }
289 
290   // Convert "x+(0-y)" into "(x-y)"
291   if( op2 == Op_SubI && phase->type(in2->in(1)) == TypeInt::ZERO )
292     return new SubINode(in1, in2->in(2) );
293 
294   // Convert "(0-y)+x" into "(x-y)"
295   if( op1 == Op_SubI && phase->type(in1->in(1)) == TypeInt::ZERO )
296     return new SubINode( in2, in1->in(2) );
297 
298   // Convert (x>>>z)+y into (x+(y<<z))>>>z for small constant z and y.
299   // Helps with array allocation math constant folding
300   // See 4790063:
301   // Unrestricted transformation is unsafe for some runtime values of 'x'
302   // ( x ==  0, z == 1, y == -1 ) fails
303   // ( x == -5, z == 1, y ==  1 ) fails
304   // Transform works for small z and small negative y when the addition
305   // (x + (y << z)) does not cross zero.
306   // Implement support for negative y and (x >= -(y << z))
307   // Have not observed cases where type information exists to support
308   // positive y and (x <= -(y << z))
309   if( op1 == Op_URShiftI && op2 == Op_ConI &&
310       in1->in(2)->Opcode() == Op_ConI ) {
311     jint z = phase->type( in1->in(2) )->is_int()->get_con() & 0x1f; // only least significant 5 bits matter
312     jint y = phase->type( in2 )->is_int()->get_con();
313 
314     if( z < 5 && -5 < y && y < 0 ) {
315       const Type *t_in11 = phase->type(in1->in(1));
316       if( t_in11 != Type::TOP && (t_in11->is_int()->_lo >= -(y << z)) ) {
317         Node *a = phase->transform( new AddINode( in1->in(1), phase->intcon(y<<z) ) );
318         return new URShiftINode( a, in1->in(2) );
319       }
320     }
321   }
322 
323   return AddNode::Ideal(phase, can_reshape);
324 }
325 
326 
327 //------------------------------Identity---------------------------------------
328 // Fold (x-y)+y  OR  y+(x-y)  into  x
Identity(PhaseGVN * phase)329 Node* AddINode::Identity(PhaseGVN* phase) {
330   if( in(1)->Opcode() == Op_SubI && phase->eqv(in(1)->in(2),in(2)) ) {
331     return in(1)->in(1);
332   }
333   else if( in(2)->Opcode() == Op_SubI && phase->eqv(in(2)->in(2),in(1)) ) {
334     return in(2)->in(1);
335   }
336   return AddNode::Identity(phase);
337 }
338 
339 
340 //------------------------------add_ring---------------------------------------
341 // Supplied function returns the sum of the inputs.  Guaranteed never
342 // to be passed a TOP or BOTTOM type, these are filtered out by
343 // pre-check.
add_ring(const Type * t0,const Type * t1) const344 const Type *AddINode::add_ring( const Type *t0, const Type *t1 ) const {
345   const TypeInt *r0 = t0->is_int(); // Handy access
346   const TypeInt *r1 = t1->is_int();
347   int lo = java_add(r0->_lo, r1->_lo);
348   int hi = java_add(r0->_hi, r1->_hi);
349   if( !(r0->is_con() && r1->is_con()) ) {
350     // Not both constants, compute approximate result
351     if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
352       lo = min_jint; hi = max_jint; // Underflow on the low side
353     }
354     if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
355       lo = min_jint; hi = max_jint; // Overflow on the high side
356     }
357     if( lo > hi ) {               // Handle overflow
358       lo = min_jint; hi = max_jint;
359     }
360   } else {
361     // both constants, compute precise result using 'lo' and 'hi'
362     // Semantics define overflow and underflow for integer addition
363     // as expected.  In particular: 0x80000000 + 0x80000000 --> 0x0
364   }
365   return TypeInt::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
366 }
367 
368 
369 //=============================================================================
370 //------------------------------Idealize---------------------------------------
Ideal(PhaseGVN * phase,bool can_reshape)371 Node *AddLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
372   Node* in1 = in(1);
373   Node* in2 = in(2);
374   int op1 = in1->Opcode();
375   int op2 = in2->Opcode();
376   // Fold (con1-x)+con2 into (con1+con2)-x
377   if ( op1 == Op_AddL && op2 == Op_SubL ) {
378     // Swap edges to try optimizations below
379     in1 = in2;
380     in2 = in(1);
381     op1 = op2;
382     op2 = in2->Opcode();
383   }
384   // Fold (con1-x)+con2 into (con1+con2)-x
385   if( op1 == Op_SubL ) {
386     const Type *t_sub1 = phase->type( in1->in(1) );
387     const Type *t_2    = phase->type( in2        );
388     if( t_sub1->singleton() && t_2->singleton() && t_sub1 != Type::TOP && t_2 != Type::TOP )
389       return new SubLNode(phase->makecon( add_ring( t_sub1, t_2 ) ), in1->in(2) );
390     // Convert "(a-b)+(c-d)" into "(a+c)-(b+d)"
391     if( op2 == Op_SubL ) {
392       // Check for dead cycle: d = (a-b)+(c-d)
393       assert( in1->in(2) != this && in2->in(2) != this,
394               "dead loop in AddLNode::Ideal" );
395       Node *sub  = new SubLNode(NULL, NULL);
396       sub->init_req(1, phase->transform(new AddLNode(in1->in(1), in2->in(1) ) ));
397       sub->init_req(2, phase->transform(new AddLNode(in1->in(2), in2->in(2) ) ));
398       return sub;
399     }
400     // Convert "(a-b)+(b+c)" into "(a+c)"
401     if( op2 == Op_AddL && in1->in(2) == in2->in(1) ) {
402       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal");
403       return new AddLNode(in1->in(1), in2->in(2));
404     }
405     // Convert "(a-b)+(c+b)" into "(a+c)"
406     if( op2 == Op_AddL && in1->in(2) == in2->in(2) ) {
407       assert(in1->in(1) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal");
408       return new AddLNode(in1->in(1), in2->in(1));
409     }
410     // Convert "(a-b)+(b-c)" into "(a-c)"
411     if( op2 == Op_SubL && in1->in(2) == in2->in(1) ) {
412       assert(in1->in(1) != this && in2->in(2) != this,"dead loop in AddLNode::Ideal");
413       return new SubLNode(in1->in(1), in2->in(2));
414     }
415     // Convert "(a-b)+(c-a)" into "(c-b)"
416     if( op2 == Op_SubL && in1->in(1) == in1->in(2) ) {
417       assert(in1->in(2) != this && in2->in(1) != this,"dead loop in AddLNode::Ideal");
418       return new SubLNode(in2->in(1), in1->in(2));
419     }
420   }
421 
422   // Convert "x+(0-y)" into "(x-y)"
423   if( op2 == Op_SubL && phase->type(in2->in(1)) == TypeLong::ZERO )
424     return new SubLNode( in1, in2->in(2) );
425 
426   // Convert "(0-y)+x" into "(x-y)"
427   if( op1 == Op_SubL && phase->type(in1->in(1)) == TypeInt::ZERO )
428     return new SubLNode( in2, in1->in(2) );
429 
430   // Convert "X+X+X+X+X...+X+Y" into "k*X+Y" or really convert "X+(X+Y)"
431   // into "(X<<1)+Y" and let shift-folding happen.
432   if( op2 == Op_AddL &&
433       in2->in(1) == in1 &&
434       op1 != Op_ConL &&
435       0 ) {
436     Node *shift = phase->transform(new LShiftLNode(in1,phase->intcon(1)));
437     return new AddLNode(shift,in2->in(2));
438   }
439 
440   return AddNode::Ideal(phase, can_reshape);
441 }
442 
443 
444 //------------------------------Identity---------------------------------------
445 // Fold (x-y)+y  OR  y+(x-y)  into  x
Identity(PhaseGVN * phase)446 Node* AddLNode::Identity(PhaseGVN* phase) {
447   if( in(1)->Opcode() == Op_SubL && phase->eqv(in(1)->in(2),in(2)) ) {
448     return in(1)->in(1);
449   }
450   else if( in(2)->Opcode() == Op_SubL && phase->eqv(in(2)->in(2),in(1)) ) {
451     return in(2)->in(1);
452   }
453   return AddNode::Identity(phase);
454 }
455 
456 
457 //------------------------------add_ring---------------------------------------
458 // Supplied function returns the sum of the inputs.  Guaranteed never
459 // to be passed a TOP or BOTTOM type, these are filtered out by
460 // pre-check.
add_ring(const Type * t0,const Type * t1) const461 const Type *AddLNode::add_ring( const Type *t0, const Type *t1 ) const {
462   const TypeLong *r0 = t0->is_long(); // Handy access
463   const TypeLong *r1 = t1->is_long();
464   jlong lo = java_add(r0->_lo, r1->_lo);
465   jlong hi = java_add(r0->_hi, r1->_hi);
466   if( !(r0->is_con() && r1->is_con()) ) {
467     // Not both constants, compute approximate result
468     if( (r0->_lo & r1->_lo) < 0 && lo >= 0 ) {
469       lo =min_jlong; hi = max_jlong; // Underflow on the low side
470     }
471     if( (~(r0->_hi | r1->_hi)) < 0 && hi < 0 ) {
472       lo = min_jlong; hi = max_jlong; // Overflow on the high side
473     }
474     if( lo > hi ) {               // Handle overflow
475       lo = min_jlong; hi = max_jlong;
476     }
477   } else {
478     // both constants, compute precise result using 'lo' and 'hi'
479     // Semantics define overflow and underflow for integer addition
480     // as expected.  In particular: 0x80000000 + 0x80000000 --> 0x0
481   }
482   return TypeLong::make( lo, hi, MAX2(r0->_widen,r1->_widen) );
483 }
484 
485 
486 //=============================================================================
487 //------------------------------add_of_identity--------------------------------
488 // Check for addition of the identity
add_of_identity(const Type * t1,const Type * t2) const489 const Type *AddFNode::add_of_identity( const Type *t1, const Type *t2 ) const {
490   // x ADD 0  should return x unless 'x' is a -zero
491   //
492   // const Type *zero = add_id();     // The additive identity
493   // jfloat f1 = t1->getf();
494   // jfloat f2 = t2->getf();
495   //
496   // if( t1->higher_equal( zero ) ) return t2;
497   // if( t2->higher_equal( zero ) ) return t1;
498 
499   return NULL;
500 }
501 
502 //------------------------------add_ring---------------------------------------
503 // Supplied function returns the sum of the inputs.
504 // This also type-checks the inputs for sanity.  Guaranteed never to
505 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
add_ring(const Type * t0,const Type * t1) const506 const Type *AddFNode::add_ring( const Type *t0, const Type *t1 ) const {
507   // We must be adding 2 float constants.
508   return TypeF::make( t0->getf() + t1->getf() );
509 }
510 
511 //------------------------------Ideal------------------------------------------
Ideal(PhaseGVN * phase,bool can_reshape)512 Node *AddFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
513   if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
514     return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
515   }
516 
517   // Floating point additions are not associative because of boundary conditions (infinity)
518   return commute(this,
519                  phase->type( in(1) )->singleton(),
520                  phase->type( in(2) )->singleton() ) ? this : NULL;
521 }
522 
523 
524 //=============================================================================
525 //------------------------------add_of_identity--------------------------------
526 // Check for addition of the identity
add_of_identity(const Type * t1,const Type * t2) const527 const Type *AddDNode::add_of_identity( const Type *t1, const Type *t2 ) const {
528   // x ADD 0  should return x unless 'x' is a -zero
529   //
530   // const Type *zero = add_id();     // The additive identity
531   // jfloat f1 = t1->getf();
532   // jfloat f2 = t2->getf();
533   //
534   // if( t1->higher_equal( zero ) ) return t2;
535   // if( t2->higher_equal( zero ) ) return t1;
536 
537   return NULL;
538 }
539 //------------------------------add_ring---------------------------------------
540 // Supplied function returns the sum of the inputs.
541 // This also type-checks the inputs for sanity.  Guaranteed never to
542 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
add_ring(const Type * t0,const Type * t1) const543 const Type *AddDNode::add_ring( const Type *t0, const Type *t1 ) const {
544   // We must be adding 2 double constants.
545   return TypeD::make( t0->getd() + t1->getd() );
546 }
547 
548 //------------------------------Ideal------------------------------------------
Ideal(PhaseGVN * phase,bool can_reshape)549 Node *AddDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
550   if( IdealizedNumerics && !phase->C->method()->is_strict() ) {
551     return AddNode::Ideal(phase, can_reshape); // commutative and associative transforms
552   }
553 
554   // Floating point additions are not associative because of boundary conditions (infinity)
555   return commute(this,
556                  phase->type( in(1) )->singleton(),
557                  phase->type( in(2) )->singleton() ) ? this : NULL;
558 }
559 
560 
561 //=============================================================================
562 //------------------------------Identity---------------------------------------
563 // If one input is a constant 0, return the other input.
Identity(PhaseGVN * phase)564 Node* AddPNode::Identity(PhaseGVN* phase) {
565   return ( phase->type( in(Offset) )->higher_equal( TypeX_ZERO ) ) ? in(Address) : this;
566 }
567 
568 //------------------------------Idealize---------------------------------------
Ideal(PhaseGVN * phase,bool can_reshape)569 Node *AddPNode::Ideal(PhaseGVN *phase, bool can_reshape) {
570   // Bail out if dead inputs
571   if( phase->type( in(Address) ) == Type::TOP ) return NULL;
572 
573   // If the left input is an add of a constant, flatten the expression tree.
574   const Node *n = in(Address);
575   if (n->is_AddP() && n->in(Base) == in(Base)) {
576     const AddPNode *addp = n->as_AddP(); // Left input is an AddP
577     assert( !addp->in(Address)->is_AddP() ||
578              addp->in(Address)->as_AddP() != addp,
579             "dead loop in AddPNode::Ideal" );
580     // Type of left input's right input
581     const Type *t = phase->type( addp->in(Offset) );
582     if( t == Type::TOP ) return NULL;
583     const TypeX *t12 = t->is_intptr_t();
584     if( t12->is_con() ) {       // Left input is an add of a constant?
585       // If the right input is a constant, combine constants
586       const Type *temp_t2 = phase->type( in(Offset) );
587       if( temp_t2 == Type::TOP ) return NULL;
588       const TypeX *t2 = temp_t2->is_intptr_t();
589       Node* address;
590       Node* offset;
591       if( t2->is_con() ) {
592         // The Add of the flattened expression
593         address = addp->in(Address);
594         offset  = phase->MakeConX(t2->get_con() + t12->get_con());
595       } else {
596         // Else move the constant to the right.  ((A+con)+B) into ((A+B)+con)
597         address = phase->transform(new AddPNode(in(Base),addp->in(Address),in(Offset)));
598         offset  = addp->in(Offset);
599       }
600       PhaseIterGVN *igvn = phase->is_IterGVN();
601       if( igvn ) {
602         set_req_X(Address,address,igvn);
603         set_req_X(Offset,offset,igvn);
604       } else {
605         set_req(Address,address);
606         set_req(Offset,offset);
607       }
608       return this;
609     }
610   }
611 
612   // Raw pointers?
613   if( in(Base)->bottom_type() == Type::TOP ) {
614     // If this is a NULL+long form (from unsafe accesses), switch to a rawptr.
615     if (phase->type(in(Address)) == TypePtr::NULL_PTR) {
616       Node* offset = in(Offset);
617       return new CastX2PNode(offset);
618     }
619   }
620 
621   // If the right is an add of a constant, push the offset down.
622   // Convert: (ptr + (offset+con)) into (ptr+offset)+con.
623   // The idea is to merge array_base+scaled_index groups together,
624   // and only have different constant offsets from the same base.
625   const Node *add = in(Offset);
626   if( add->Opcode() == Op_AddX && add->in(1) != add ) {
627     const Type *t22 = phase->type( add->in(2) );
628     if( t22->singleton() && (t22 != Type::TOP) ) {  // Right input is an add of a constant?
629       set_req(Address, phase->transform(new AddPNode(in(Base),in(Address),add->in(1))));
630       set_req(Offset, add->in(2));
631       PhaseIterGVN *igvn = phase->is_IterGVN();
632       if (add->outcnt() == 0 && igvn) {
633         // add disconnected.
634         igvn->_worklist.push((Node*)add);
635       }
636       return this;              // Made progress
637     }
638   }
639 
640   return NULL;                  // No progress
641 }
642 
643 //------------------------------bottom_type------------------------------------
644 // Bottom-type is the pointer-type with unknown offset.
bottom_type() const645 const Type *AddPNode::bottom_type() const {
646   if (in(Address) == NULL)  return TypePtr::BOTTOM;
647   const TypePtr *tp = in(Address)->bottom_type()->isa_ptr();
648   if( !tp ) return Type::TOP;   // TOP input means TOP output
649   assert( in(Offset)->Opcode() != Op_ConP, "" );
650   const Type *t = in(Offset)->bottom_type();
651   if( t == Type::TOP )
652     return tp->add_offset(Type::OffsetTop);
653   const TypeX *tx = t->is_intptr_t();
654   intptr_t txoffset = Type::OffsetBot;
655   if (tx->is_con()) {   // Left input is an add of a constant?
656     txoffset = tx->get_con();
657   }
658   return tp->add_offset(txoffset);
659 }
660 
661 //------------------------------Value------------------------------------------
Value(PhaseGVN * phase) const662 const Type* AddPNode::Value(PhaseGVN* phase) const {
663   // Either input is TOP ==> the result is TOP
664   const Type *t1 = phase->type( in(Address) );
665   const Type *t2 = phase->type( in(Offset) );
666   if( t1 == Type::TOP ) return Type::TOP;
667   if( t2 == Type::TOP ) return Type::TOP;
668 
669   // Left input is a pointer
670   const TypePtr *p1 = t1->isa_ptr();
671   // Right input is an int
672   const TypeX *p2 = t2->is_intptr_t();
673   // Add 'em
674   intptr_t p2offset = Type::OffsetBot;
675   if (p2->is_con()) {   // Left input is an add of a constant?
676     p2offset = p2->get_con();
677   }
678   return p1->add_offset(p2offset);
679 }
680 
681 //------------------------Ideal_base_and_offset--------------------------------
682 // Split an oop pointer into a base and offset.
683 // (The offset might be Type::OffsetBot in the case of an array.)
684 // Return the base, or NULL if failure.
Ideal_base_and_offset(Node * ptr,PhaseTransform * phase,intptr_t & offset)685 Node* AddPNode::Ideal_base_and_offset(Node* ptr, PhaseTransform* phase,
686                                       // second return value:
687                                       intptr_t& offset) {
688   if (ptr->is_AddP()) {
689     Node* base = ptr->in(AddPNode::Base);
690     Node* addr = ptr->in(AddPNode::Address);
691     Node* offs = ptr->in(AddPNode::Offset);
692     if (base == addr || base->is_top()) {
693       offset = phase->find_intptr_t_con(offs, Type::OffsetBot);
694       if (offset != Type::OffsetBot) {
695         return addr;
696       }
697     }
698   }
699   offset = Type::OffsetBot;
700   return NULL;
701 }
702 
703 //------------------------------unpack_offsets----------------------------------
704 // Collect the AddP offset values into the elements array, giving up
705 // if there are more than length.
unpack_offsets(Node * elements[],int length)706 int AddPNode::unpack_offsets(Node* elements[], int length) {
707   int count = 0;
708   Node* addr = this;
709   Node* base = addr->in(AddPNode::Base);
710   while (addr->is_AddP()) {
711     if (addr->in(AddPNode::Base) != base) {
712       // give up
713       return -1;
714     }
715     elements[count++] = addr->in(AddPNode::Offset);
716     if (count == length) {
717       // give up
718       return -1;
719     }
720     addr = addr->in(AddPNode::Address);
721   }
722   if (addr != base) {
723     return -1;
724   }
725   return count;
726 }
727 
728 //------------------------------match_edge-------------------------------------
729 // Do we Match on this edge index or not?  Do not match base pointer edge
match_edge(uint idx) const730 uint AddPNode::match_edge(uint idx) const {
731   return idx > Base;
732 }
733 
734 //=============================================================================
735 //------------------------------Identity---------------------------------------
Identity(PhaseGVN * phase)736 Node* OrINode::Identity(PhaseGVN* phase) {
737   // x | x => x
738   if (phase->eqv(in(1), in(2))) {
739     return in(1);
740   }
741 
742   return AddNode::Identity(phase);
743 }
744 
745 //------------------------------add_ring---------------------------------------
746 // Supplied function returns the sum of the inputs IN THE CURRENT RING.  For
747 // the logical operations the ring's ADD is really a logical OR function.
748 // This also type-checks the inputs for sanity.  Guaranteed never to
749 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
add_ring(const Type * t0,const Type * t1) const750 const Type *OrINode::add_ring( const Type *t0, const Type *t1 ) const {
751   const TypeInt *r0 = t0->is_int(); // Handy access
752   const TypeInt *r1 = t1->is_int();
753 
754   // If both args are bool, can figure out better types
755   if ( r0 == TypeInt::BOOL ) {
756     if ( r1 == TypeInt::ONE) {
757       return TypeInt::ONE;
758     } else if ( r1 == TypeInt::BOOL ) {
759       return TypeInt::BOOL;
760     }
761   } else if ( r0 == TypeInt::ONE ) {
762     if ( r1 == TypeInt::BOOL ) {
763       return TypeInt::ONE;
764     }
765   }
766 
767   // If either input is not a constant, just return all integers.
768   if( !r0->is_con() || !r1->is_con() )
769     return TypeInt::INT;        // Any integer, but still no symbols.
770 
771   // Otherwise just OR them bits.
772   return TypeInt::make( r0->get_con() | r1->get_con() );
773 }
774 
775 //=============================================================================
776 //------------------------------Identity---------------------------------------
Identity(PhaseGVN * phase)777 Node* OrLNode::Identity(PhaseGVN* phase) {
778   // x | x => x
779   if (phase->eqv(in(1), in(2))) {
780     return in(1);
781   }
782 
783   return AddNode::Identity(phase);
784 }
785 
786 //------------------------------add_ring---------------------------------------
add_ring(const Type * t0,const Type * t1) const787 const Type *OrLNode::add_ring( const Type *t0, const Type *t1 ) const {
788   const TypeLong *r0 = t0->is_long(); // Handy access
789   const TypeLong *r1 = t1->is_long();
790 
791   // If either input is not a constant, just return all integers.
792   if( !r0->is_con() || !r1->is_con() )
793     return TypeLong::LONG;      // Any integer, but still no symbols.
794 
795   // Otherwise just OR them bits.
796   return TypeLong::make( r0->get_con() | r1->get_con() );
797 }
798 
799 //=============================================================================
800 //------------------------------add_ring---------------------------------------
801 // Supplied function returns the sum of the inputs IN THE CURRENT RING.  For
802 // the logical operations the ring's ADD is really a logical OR function.
803 // This also type-checks the inputs for sanity.  Guaranteed never to
804 // be passed a TOP or BOTTOM type, these are filtered out by pre-check.
add_ring(const Type * t0,const Type * t1) const805 const Type *XorINode::add_ring( const Type *t0, const Type *t1 ) const {
806   const TypeInt *r0 = t0->is_int(); // Handy access
807   const TypeInt *r1 = t1->is_int();
808 
809   // Complementing a boolean?
810   if( r0 == TypeInt::BOOL && ( r1 == TypeInt::ONE
811                                || r1 == TypeInt::BOOL))
812     return TypeInt::BOOL;
813 
814   if( !r0->is_con() || !r1->is_con() ) // Not constants
815     return TypeInt::INT;        // Any integer, but still no symbols.
816 
817   // Otherwise just XOR them bits.
818   return TypeInt::make( r0->get_con() ^ r1->get_con() );
819 }
820 
821 //=============================================================================
822 //------------------------------add_ring---------------------------------------
add_ring(const Type * t0,const Type * t1) const823 const Type *XorLNode::add_ring( const Type *t0, const Type *t1 ) const {
824   const TypeLong *r0 = t0->is_long(); // Handy access
825   const TypeLong *r1 = t1->is_long();
826 
827   // If either input is not a constant, just return all integers.
828   if( !r0->is_con() || !r1->is_con() )
829     return TypeLong::LONG;      // Any integer, but still no symbols.
830 
831   // Otherwise just OR them bits.
832   return TypeLong::make( r0->get_con() ^ r1->get_con() );
833 }
834 
835 //=============================================================================
836 //------------------------------add_ring---------------------------------------
837 // Supplied function returns the sum of the inputs.
add_ring(const Type * t0,const Type * t1) const838 const Type *MaxINode::add_ring( const Type *t0, const Type *t1 ) const {
839   const TypeInt *r0 = t0->is_int(); // Handy access
840   const TypeInt *r1 = t1->is_int();
841 
842   // Otherwise just MAX them bits.
843   return TypeInt::make( MAX2(r0->_lo,r1->_lo), MAX2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
844 }
845 
846 //=============================================================================
847 //------------------------------Idealize---------------------------------------
848 // MINs show up in range-check loop limit calculations.  Look for
849 // "MIN2(x+c0,MIN2(y,x+c1))".  Pick the smaller constant: "MIN2(x+c0,y)"
Ideal(PhaseGVN * phase,bool can_reshape)850 Node *MinINode::Ideal(PhaseGVN *phase, bool can_reshape) {
851   Node *progress = NULL;
852   // Force a right-spline graph
853   Node *l = in(1);
854   Node *r = in(2);
855   // Transform  MinI1( MinI2(a,b), c)  into  MinI1( a, MinI2(b,c) )
856   // to force a right-spline graph for the rest of MinINode::Ideal().
857   if( l->Opcode() == Op_MinI ) {
858     assert( l != l->in(1), "dead loop in MinINode::Ideal" );
859     r = phase->transform(new MinINode(l->in(2),r));
860     l = l->in(1);
861     set_req(1, l);
862     set_req(2, r);
863     return this;
864   }
865 
866   // Get left input & constant
867   Node *x = l;
868   int x_off = 0;
869   if( x->Opcode() == Op_AddI && // Check for "x+c0" and collect constant
870       x->in(2)->is_Con() ) {
871     const Type *t = x->in(2)->bottom_type();
872     if( t == Type::TOP ) return NULL;  // No progress
873     x_off = t->is_int()->get_con();
874     x = x->in(1);
875   }
876 
877   // Scan a right-spline-tree for MINs
878   Node *y = r;
879   int y_off = 0;
880   // Check final part of MIN tree
881   if( y->Opcode() == Op_AddI && // Check for "y+c1" and collect constant
882       y->in(2)->is_Con() ) {
883     const Type *t = y->in(2)->bottom_type();
884     if( t == Type::TOP ) return NULL;  // No progress
885     y_off = t->is_int()->get_con();
886     y = y->in(1);
887   }
888   if( x->_idx > y->_idx && r->Opcode() != Op_MinI ) {
889     swap_edges(1, 2);
890     return this;
891   }
892 
893 
894   if( r->Opcode() == Op_MinI ) {
895     assert( r != r->in(2), "dead loop in MinINode::Ideal" );
896     y = r->in(1);
897     // Check final part of MIN tree
898     if( y->Opcode() == Op_AddI &&// Check for "y+c1" and collect constant
899         y->in(2)->is_Con() ) {
900       const Type *t = y->in(2)->bottom_type();
901       if( t == Type::TOP ) return NULL;  // No progress
902       y_off = t->is_int()->get_con();
903       y = y->in(1);
904     }
905 
906     if( x->_idx > y->_idx )
907       return new MinINode(r->in(1),phase->transform(new MinINode(l,r->in(2))));
908 
909     // See if covers: MIN2(x+c0,MIN2(y+c1,z))
910     if( !phase->eqv(x,y) ) return NULL;
911     // If (y == x) transform MIN2(x+c0, MIN2(x+c1,z)) into
912     // MIN2(x+c0 or x+c1 which less, z).
913     return new MinINode(phase->transform(new AddINode(x,phase->intcon(MIN2(x_off,y_off)))),r->in(2));
914   } else {
915     // See if covers: MIN2(x+c0,y+c1)
916     if( !phase->eqv(x,y) ) return NULL;
917     // If (y == x) transform MIN2(x+c0,x+c1) into x+c0 or x+c1 which less.
918     return new AddINode(x,phase->intcon(MIN2(x_off,y_off)));
919   }
920 
921 }
922 
923 //------------------------------add_ring---------------------------------------
924 // Supplied function returns the sum of the inputs.
add_ring(const Type * t0,const Type * t1) const925 const Type *MinINode::add_ring( const Type *t0, const Type *t1 ) const {
926   const TypeInt *r0 = t0->is_int(); // Handy access
927   const TypeInt *r1 = t1->is_int();
928 
929   // Otherwise just MIN them bits.
930   return TypeInt::make( MIN2(r0->_lo,r1->_lo), MIN2(r0->_hi,r1->_hi), MAX2(r0->_widen,r1->_widen) );
931 }
932 
933 //------------------------------add_ring---------------------------------------
add_ring(const Type * t0,const Type * t1) const934 const Type *MinFNode::add_ring( const Type *t0, const Type *t1 ) const {
935   const TypeF *r0 = t0->is_float_constant();
936   const TypeF *r1 = t1->is_float_constant();
937 
938   if (r0->is_nan()) {
939     return r0;
940   }
941   if (r1->is_nan()) {
942     return r1;
943   }
944 
945   float f0 = r0->getf();
946   float f1 = r1->getf();
947   if (f0 != 0.0f || f1 != 0.0f) {
948     return f0 < f1 ? r0 : r1;
949   }
950 
951   // handle min of 0.0, -0.0 case.
952   return (jint_cast(f0) < jint_cast(f1)) ? r0 : r1;
953 }
954 
955 //------------------------------add_ring---------------------------------------
add_ring(const Type * t0,const Type * t1) const956 const Type *MinDNode::add_ring( const Type *t0, const Type *t1 ) const {
957   const TypeD *r0 = t0->is_double_constant();
958   const TypeD *r1 = t1->is_double_constant();
959 
960   if (r0->is_nan()) {
961     return r0;
962   }
963   if (r1->is_nan()) {
964     return r1;
965   }
966 
967   double d0 = r0->getd();
968   double d1 = r1->getd();
969   if (d0 != 0.0 || d1 != 0.0) {
970     return d0 < d1 ? r0 : r1;
971   }
972 
973   // handle min of 0.0, -0.0 case.
974   return (jlong_cast(d0) < jlong_cast(d1)) ? r0 : r1;
975 }
976 
977 //------------------------------add_ring---------------------------------------
add_ring(const Type * t0,const Type * t1) const978 const Type *MaxFNode::add_ring( const Type *t0, const Type *t1 ) const {
979   const TypeF *r0 = t0->is_float_constant();
980   const TypeF *r1 = t1->is_float_constant();
981 
982   if (r0->is_nan()) {
983     return r0;
984   }
985   if (r1->is_nan()) {
986     return r1;
987   }
988 
989   float f0 = r0->getf();
990   float f1 = r1->getf();
991   if (f0 != 0.0f || f1 != 0.0f) {
992     return f0 > f1 ? r0 : r1;
993   }
994 
995   // handle max of 0.0,-0.0 case.
996   return (jint_cast(f0) > jint_cast(f1)) ? r0 : r1;
997 }
998 
999 //------------------------------add_ring---------------------------------------
add_ring(const Type * t0,const Type * t1) const1000 const Type *MaxDNode::add_ring( const Type *t0, const Type *t1 ) const {
1001   const TypeD *r0 = t0->is_double_constant();
1002   const TypeD *r1 = t1->is_double_constant();
1003 
1004   if (r0->is_nan()) {
1005     return r0;
1006   }
1007   if (r1->is_nan()) {
1008     return r1;
1009   }
1010 
1011   double d0 = r0->getd();
1012   double d1 = r1->getd();
1013   if (d0 != 0.0 || d1 != 0.0) {
1014     return d0 > d1 ? r0 : r1;
1015   }
1016 
1017   // handle max of 0.0, -0.0 case.
1018   return (jlong_cast(d0) > jlong_cast(d1)) ? r0 : r1;
1019 }
1020