1 /*
  2  * Copyright (c) 1997, 2022, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
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 24 
 25 #ifndef SHARE_OPTO_SUBNODE_HPP
 26 #define SHARE_OPTO_SUBNODE_HPP
 27 
 28 #include "opto/node.hpp"
 29 #include "opto/opcodes.hpp"
 30 #include "opto/type.hpp"
 31 
 32 // Portions of code courtesy of Clifford Click
 33 
 34 //------------------------------SUBNode----------------------------------------
 35 // Class SUBTRACTION functionality.  This covers all the usual 'subtract'
 36 // behaviors.  Subtract-integer, -float, -double, binary xor, compare-integer,
 37 // -float, and -double are all inherited from this class.  The compare
 38 // functions behave like subtract functions, except that all negative answers
 39 // are compressed into -1, and all positive answers compressed to 1.
 40 class SubNode : public Node {
 41 public:
 42   SubNode( Node *in1, Node *in2 ) : Node(0,in1,in2) {
 43     init_class_id(Class_Sub);
 44   }
 45 
 46   // Handle algebraic identities here.  If we have an identity, return the Node
 47   // we are equivalent to.  We look for "add of zero" as an identity.
 48   virtual Node* Identity(PhaseGVN* phase);
 49 
 50   // Compute a new Type for this node.  Basically we just do the pre-check,
 51   // then call the virtual add() to set the type.
 52   virtual const Type* Value(PhaseGVN* phase) const;
 53   const Type* Value_common( PhaseTransform *phase ) const;
 54 
 55   // Supplied function returns the subtractend of the inputs.
 56   // This also type-checks the inputs for sanity.  Guaranteed never to
 57   // be passed a TOP or BOTTOM type, these are filtered out by a pre-check.
 58   virtual const Type *sub( const Type *, const Type * ) const = 0;
 59 
 60   // Supplied function to return the additive identity type.
 61   // This is returned whenever the subtracts inputs are the same.
 62   virtual const Type *add_id() const = 0;
 63 
 64   static SubNode* make(Node* in1, Node* in2, BasicType bt);
 65 };
 66 
 67 
 68 // NOTE: SubINode should be taken away and replaced by add and negate
 69 //------------------------------SubINode---------------------------------------
 70 // Subtract 2 integers
 71 class SubINode : public SubNode {
 72 public:
 73   SubINode( Node *in1, Node *in2 ) : SubNode(in1,in2) {}
 74   virtual int Opcode() const;
 75   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 76   virtual const Type *sub( const Type *, const Type * ) const;
 77   const Type *add_id() const { return TypeInt::ZERO; }
 78   const Type *bottom_type() const { return TypeInt::INT; }
 79   virtual uint ideal_reg() const { return Op_RegI; }
 80 };
 81 
 82 //------------------------------SubLNode---------------------------------------
 83 // Subtract 2 integers
 84 class SubLNode : public SubNode {
 85 public:
 86   SubLNode( Node *in1, Node *in2 ) : SubNode(in1,in2) {}
 87   virtual int Opcode() const;
 88   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
 89   virtual const Type *sub( const Type *, const Type * ) const;
 90   const Type *add_id() const { return TypeLong::ZERO; }
 91   const Type *bottom_type() const { return TypeLong::LONG; }
 92   virtual uint ideal_reg() const { return Op_RegL; }
 93 };
 94 
 95 // NOTE: SubFPNode should be taken away and replaced by add and negate
 96 //------------------------------SubFPNode--------------------------------------
 97 // Subtract 2 floats or doubles
 98 class SubFPNode : public SubNode {
 99 protected:
100   SubFPNode( Node *in1, Node *in2 ) : SubNode(in1,in2) {}
101 public:
102   const Type* Value(PhaseGVN* phase) const;
103 };
104 
105 // NOTE: SubFNode should be taken away and replaced by add and negate
106 //------------------------------SubFNode---------------------------------------
107 // Subtract 2 doubles
108 class SubFNode : public SubFPNode {
109 public:
110   SubFNode( Node *in1, Node *in2 ) : SubFPNode(in1,in2) {}
111   virtual int Opcode() const;
112   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
113   virtual const Type *sub( const Type *, const Type * ) const;
114   const Type   *add_id() const { return TypeF::ZERO; }
115   const Type   *bottom_type() const { return Type::FLOAT; }
116   virtual uint  ideal_reg() const { return Op_RegF; }
117 };
118 
119 // NOTE: SubDNode should be taken away and replaced by add and negate
120 //------------------------------SubDNode---------------------------------------
121 // Subtract 2 doubles
122 class SubDNode : public SubFPNode {
123 public:
124   SubDNode( Node *in1, Node *in2 ) : SubFPNode(in1,in2) {}
125   virtual int Opcode() const;
126   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
127   virtual const Type *sub( const Type *, const Type * ) const;
128   const Type   *add_id() const { return TypeD::ZERO; }
129   const Type   *bottom_type() const { return Type::DOUBLE; }
130   virtual uint  ideal_reg() const { return Op_RegD; }
131 };
132 
133 //------------------------------CmpNode---------------------------------------
134 // Compare 2 values, returning condition codes (-1, 0 or 1).
135 class CmpNode : public SubNode {
136 public:
137   CmpNode( Node *in1, Node *in2 ) : SubNode(in1,in2) {
138     init_class_id(Class_Cmp);
139   }
140   virtual Node* Identity(PhaseGVN* phase);
141   const Type *add_id() const { return TypeInt::ZERO; }
142   const Type *bottom_type() const { return TypeInt::CC; }
143   virtual uint ideal_reg() const { return Op_RegFlags; }
144 
145   static CmpNode *make(Node *in1, Node *in2, BasicType bt, bool unsigned_comp = false);
146 
147 #ifndef PRODUCT
148   // CmpNode and subclasses include all data inputs (until hitting a control
149   // boundary) in their related node set, as well as all outputs until and
150   // including eventual control nodes and their projections.
151   virtual void related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const;
152 #endif
153 };
154 
155 //------------------------------CmpINode---------------------------------------
156 // Compare 2 signed values, returning condition codes (-1, 0 or 1).
157 class CmpINode : public CmpNode {
158 public:
159   CmpINode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
160   virtual int Opcode() const;
161   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
162   virtual const Type *sub( const Type *, const Type * ) const;
163 };
164 
165 //------------------------------CmpUNode---------------------------------------
166 // Compare 2 unsigned values (integer or pointer), returning condition codes (-1, 0 or 1).
167 class CmpUNode : public CmpNode {
168 public:
169   CmpUNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
170   virtual int Opcode() const;
171   virtual const Type *sub( const Type *, const Type * ) const;
172   const Type* Value(PhaseGVN* phase) const;
173   bool is_index_range_check() const;
174 };
175 
176 //------------------------------CmpPNode---------------------------------------
177 // Compare 2 pointer values, returning condition codes (-1, 0 or 1).
178 class CmpPNode : public CmpNode {
179 public:
180   CmpPNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
181   virtual int Opcode() const;
182   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
183   virtual const Type *sub( const Type *, const Type * ) const;
184 };
185 
186 //------------------------------CmpNNode--------------------------------------
187 // Compare 2 narrow oop values, returning condition codes (-1, 0 or 1).
188 class CmpNNode : public CmpNode {
189 public:
190   CmpNNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
191   virtual int Opcode() const;
192   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
193   virtual const Type *sub( const Type *, const Type * ) const;
194 };
195 
196 //------------------------------CmpLNode---------------------------------------
197 // Compare 2 long values, returning condition codes (-1, 0 or 1).
198 class CmpLNode : public CmpNode {
199 public:
200   CmpLNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
201   virtual int    Opcode() const;
202   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
203   virtual const Type *sub( const Type *, const Type * ) const;
204 };
205 
206 //------------------------------CmpULNode---------------------------------------
207 // Compare 2 unsigned long values, returning condition codes (-1, 0 or 1).
208 class CmpULNode : public CmpNode {
209 public:
210   CmpULNode(Node* in1, Node* in2) : CmpNode(in1, in2) { }
211   virtual int Opcode() const;
212   virtual const Type* sub(const Type*, const Type*) const;
213 };
214 
215 //------------------------------CmpL3Node--------------------------------------
216 // Compare 2 long values, returning integer value (-1, 0 or 1).
217 class CmpL3Node : public CmpLNode {
218 public:
219   CmpL3Node( Node *in1, Node *in2 ) : CmpLNode(in1,in2) {
220     // Since it is not consumed by Bools, it is not really a Cmp.
221     init_class_id(Class_Sub);
222   }
223   virtual int    Opcode() const;
224   virtual uint ideal_reg() const { return Op_RegI; }
225 };
226 
227 //------------------------------CmpFNode---------------------------------------
228 // Compare 2 float values, returning condition codes (-1, 0 or 1).
229 // This implements the Java bytecode fcmpl, so unordered returns -1.
230 // Operands may not commute.
231 class CmpFNode : public CmpNode {
232 public:
233   CmpFNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
234   virtual int Opcode() const;
235   virtual const Type *sub( const Type *, const Type * ) const { ShouldNotReachHere(); return NULL; }
236   const Type* Value(PhaseGVN* phase) const;
237 };
238 
239 //------------------------------CmpF3Node--------------------------------------
240 // Compare 2 float values, returning integer value (-1, 0 or 1).
241 // This implements the Java bytecode fcmpl, so unordered returns -1.
242 // Operands may not commute.
243 class CmpF3Node : public CmpFNode {
244 public:
245   CmpF3Node( Node *in1, Node *in2 ) : CmpFNode(in1,in2) {
246     // Since it is not consumed by Bools, it is not really a Cmp.
247     init_class_id(Class_Sub);
248   }
249   virtual int Opcode() const;
250   // Since it is not consumed by Bools, it is not really a Cmp.
251   virtual uint ideal_reg() const { return Op_RegI; }
252 };
253 
254 
255 //------------------------------CmpDNode---------------------------------------
256 // Compare 2 double values, returning condition codes (-1, 0 or 1).
257 // This implements the Java bytecode dcmpl, so unordered returns -1.
258 // Operands may not commute.
259 class CmpDNode : public CmpNode {
260 public:
261   CmpDNode( Node *in1, Node *in2 ) : CmpNode(in1,in2) {}
262   virtual int Opcode() const;
263   virtual const Type *sub( const Type *, const Type * ) const { ShouldNotReachHere(); return NULL; }
264   const Type* Value(PhaseGVN* phase) const;
265   virtual Node  *Ideal(PhaseGVN *phase, bool can_reshape);
266 };
267 
268 //------------------------------CmpD3Node--------------------------------------
269 // Compare 2 double values, returning integer value (-1, 0 or 1).
270 // This implements the Java bytecode dcmpl, so unordered returns -1.
271 // Operands may not commute.
272 class CmpD3Node : public CmpDNode {
273 public:
274   CmpD3Node( Node *in1, Node *in2 ) : CmpDNode(in1,in2) {
275     // Since it is not consumed by Bools, it is not really a Cmp.
276     init_class_id(Class_Sub);
277   }
278   virtual int Opcode() const;
279   virtual uint ideal_reg() const { return Op_RegI; }
280 };
281 
282 
283 //------------------------------BoolTest---------------------------------------
284 // Convert condition codes to a boolean test value (0 or -1).
285 // We pick the values as 3 bits; the low order 2 bits we compare against the
286 // condition codes, the high bit flips the sense of the result.
287 // For vector compares, additionally, the 4th bit indicates if the compare is unsigned
288 struct BoolTest {
289   enum mask { eq = 0, ne = 4, le = 5, ge = 7, lt = 3, gt = 1, overflow = 2, no_overflow = 6, never = 8, illegal = 9,
290               // The following values are used with vector compares
291               // A BoolTest value should not be constructed for such values
292               unsigned_compare = 16,
293               ule = unsigned_compare | le, uge = unsigned_compare | ge, ult = unsigned_compare | lt, ugt = unsigned_compare | gt };
294   mask _test;
295   BoolTest( mask btm ) : _test(btm) { assert((btm & unsigned_compare) == 0, "unsupported");}
296   const Type *cc2logical( const Type *CC ) const;
297   // Commute the test.  I use a small table lookup.  The table is created as
298   // a simple char array where each element is the ASCII version of a 'mask'
299   // enum from above.
300   mask commute( ) const { return mask("032147658"[_test]-'0'); }
301   mask negate( ) const { return mask(_test^4); }
302   bool is_canonical( ) const { return (_test == BoolTest::ne || _test == BoolTest::lt || _test == BoolTest::le || _test == BoolTest::overflow); }
303   bool is_less( )  const { return _test == BoolTest::lt || _test == BoolTest::le; }
304   bool is_greater( ) const { return _test == BoolTest::gt || _test == BoolTest::ge; }
305   void dump_on(outputStream *st) const;
306   mask merge(BoolTest other) const;
307 };
308 
309 //------------------------------BoolNode---------------------------------------
310 // A Node to convert a Condition Codes to a Logical result.
311 class BoolNode : public Node {
312   virtual uint hash() const;
313   virtual bool cmp( const Node &n ) const;
314   virtual uint size_of() const;
315 
316   // Try to optimize signed integer comparison
317   Node* fold_cmpI(PhaseGVN* phase, SubNode* cmp, Node* cmp1, int cmp_op,
318                   int cmp1_op, const TypeInt* cmp2_type);
319 public:
320   const BoolTest _test;
321   BoolNode(Node *cc, BoolTest::mask t): Node(NULL,cc), _test(t) {
322     init_class_id(Class_Bool);
323   }
324   // Convert an arbitrary int value to a Bool or other suitable predicate.
325   static Node* make_predicate(Node* test_value, PhaseGVN* phase);
326   // Convert self back to an integer value.
327   Node* as_int_value(PhaseGVN* phase);
328   // Invert sense of self, returning new Bool.
329   BoolNode* negate(PhaseGVN* phase);
330   virtual int Opcode() const;
331   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
332   virtual const Type* Value(PhaseGVN* phase) const;
333   virtual const Type *bottom_type() const { return TypeInt::BOOL; }
334   uint match_edge(uint idx) const { return 0; }
335   virtual uint ideal_reg() const { return Op_RegI; }
336 
337   bool is_counted_loop_exit_test();
338 #ifndef PRODUCT
339   virtual void dump_spec(outputStream *st) const;
340   virtual void related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const;
341 #endif
342 };
343 
344 //------------------------------AbsNode----------------------------------------
345 // Abstract class for absolute value.  Mostly used to get a handy wrapper
346 // for finding this pattern in the graph.
347 class AbsNode : public Node {
348 public:
349   AbsNode( Node *value ) : Node(0,value) {}
350   virtual Node* Identity(PhaseGVN* phase);
351   virtual Node* Ideal(PhaseGVN* phase, bool can_reshape);
352   virtual const Type* Value(PhaseGVN* phase) const;
353 };
354 
355 //------------------------------AbsINode---------------------------------------
356 // Absolute value an integer.  Since a naive graph involves control flow, we
357 // "match" it in the ideal world (so the control flow can be removed).
358 class AbsINode : public AbsNode {
359 public:
360   AbsINode( Node *in1 ) : AbsNode(in1) {}
361   virtual int Opcode() const;
362   const Type *bottom_type() const { return TypeInt::INT; }
363   virtual uint ideal_reg() const { return Op_RegI; }
364 };
365 
366 //------------------------------AbsLNode---------------------------------------
367 // Absolute value a long.  Since a naive graph involves control flow, we
368 // "match" it in the ideal world (so the control flow can be removed).
369 class AbsLNode : public AbsNode {
370 public:
371   AbsLNode( Node *in1 ) : AbsNode(in1) {}
372   virtual int Opcode() const;
373   const Type *bottom_type() const { return TypeLong::LONG; }
374   virtual uint ideal_reg() const { return Op_RegL; }
375 };
376 
377 //------------------------------AbsFNode---------------------------------------
378 // Absolute value a float, a common float-point idiom with a cheap hardware
379 // implementation on most chips.  Since a naive graph involves control flow, we
380 // "match" it in the ideal world (so the control flow can be removed).
381 class AbsFNode : public AbsNode {
382 public:
383   AbsFNode( Node *in1 ) : AbsNode(in1) {}
384   virtual int Opcode() const;
385   const Type *bottom_type() const { return Type::FLOAT; }
386   virtual uint ideal_reg() const { return Op_RegF; }
387 };
388 
389 //------------------------------AbsDNode---------------------------------------
390 // Absolute value a double, a common float-point idiom with a cheap hardware
391 // implementation on most chips.  Since a naive graph involves control flow, we
392 // "match" it in the ideal world (so the control flow can be removed).
393 class AbsDNode : public AbsNode {
394 public:
395   AbsDNode( Node *in1 ) : AbsNode(in1) {}
396   virtual int Opcode() const;
397   const Type *bottom_type() const { return Type::DOUBLE; }
398   virtual uint ideal_reg() const { return Op_RegD; }
399 };
400 
401 
402 //------------------------------CmpLTMaskNode----------------------------------
403 // If p < q, return -1 else return 0.  Nice for flow-free idioms.
404 class CmpLTMaskNode : public Node {
405 public:
406   CmpLTMaskNode( Node *p, Node *q ) : Node(0, p, q) {}
407   virtual int Opcode() const;
408   const Type *bottom_type() const { return TypeInt::INT; }
409   virtual uint ideal_reg() const { return Op_RegI; }
410 };
411 
412 
413 //------------------------------NegNode----------------------------------------
414 class NegNode : public Node {
415 public:
416   NegNode( Node *in1 ) : Node(0,in1) {}
417 };
418 
419 //------------------------------NegINode---------------------------------------
420 // Negate value an int.  For int values, negation is the same as subtraction
421 // from zero
422 class NegINode : public NegNode {
423 public:
424   NegINode(Node *in1) : NegNode(in1) {}
425   virtual int Opcode() const;
426   const Type *bottom_type() const { return TypeInt::INT; }
427   virtual uint ideal_reg() const { return Op_RegI; }
428 };
429 
430 //------------------------------NegLNode---------------------------------------
431 // Negate value an int.  For int values, negation is the same as subtraction
432 // from zero
433 class NegLNode : public NegNode {
434 public:
435   NegLNode(Node *in1) : NegNode(in1) {}
436   virtual int Opcode() const;
437   const Type *bottom_type() const { return TypeLong::LONG; }
438   virtual uint ideal_reg() const { return Op_RegL; }
439 };
440 
441 //------------------------------NegFNode---------------------------------------
442 // Negate value a float.  Negating 0.0 returns -0.0, but subtracting from
443 // zero returns +0.0 (per JVM spec on 'fneg' bytecode).  As subtraction
444 // cannot be used to replace negation we have to implement negation as ideal
445 // node; note that negation and addition can replace subtraction.
446 class NegFNode : public NegNode {
447 public:
448   NegFNode( Node *in1 ) : NegNode(in1) {}
449   virtual int Opcode() const;
450   const Type *bottom_type() const { return Type::FLOAT; }
451   virtual uint ideal_reg() const { return Op_RegF; }
452 };
453 
454 //------------------------------NegDNode---------------------------------------
455 // Negate value a double.  Negating 0.0 returns -0.0, but subtracting from
456 // zero returns +0.0 (per JVM spec on 'dneg' bytecode).  As subtraction
457 // cannot be used to replace negation we have to implement negation as ideal
458 // node; note that negation and addition can replace subtraction.
459 class NegDNode : public NegNode {
460 public:
461   NegDNode( Node *in1 ) : NegNode(in1) {}
462   virtual int Opcode() const;
463   const Type *bottom_type() const { return Type::DOUBLE; }
464   virtual uint ideal_reg() const { return Op_RegD; }
465 };
466 
467 //------------------------------AtanDNode--------------------------------------
468 // arcus tangens of a double
469 class AtanDNode : public Node {
470 public:
471   AtanDNode(Node *c, Node *in1, Node *in2  ) : Node(c, in1, in2) {}
472   virtual int Opcode() const;
473   const Type *bottom_type() const { return Type::DOUBLE; }
474   virtual uint ideal_reg() const { return Op_RegD; }
475 };
476 
477 
478 //------------------------------SqrtDNode--------------------------------------
479 // square root a double
480 class SqrtDNode : public Node {
481 public:
482   SqrtDNode(Compile* C, Node *c, Node *in1) : Node(c, in1) {
483     init_flags(Flag_is_expensive);
484     C->add_expensive_node(this);
485   }
486   virtual int Opcode() const;
487   const Type *bottom_type() const { return Type::DOUBLE; }
488   virtual uint ideal_reg() const { return Op_RegD; }
489   virtual const Type* Value(PhaseGVN* phase) const;
490 };
491 
492 //------------------------------SqrtFNode--------------------------------------
493 // square root a float
494 class SqrtFNode : public Node {
495 public:
496   SqrtFNode(Compile* C, Node *c, Node *in1) : Node(c, in1) {
497     init_flags(Flag_is_expensive);
498     if (c != NULL) {
499       // Treat node only as expensive if a control input is set because it might
500       // be created from a SqrtDNode in ConvD2FNode::Ideal() that was found to
501       // be unique and therefore has no control input.
502       C->add_expensive_node(this);
503     }
504   }
505   virtual int Opcode() const;
506   const Type *bottom_type() const { return Type::FLOAT; }
507   virtual uint ideal_reg() const { return Op_RegF; }
508   virtual const Type* Value(PhaseGVN* phase) const;
509 };
510 
511 //-------------------------------ReverseBytesINode--------------------------------
512 // reverse bytes of an integer
513 class ReverseBytesINode : public Node {
514 public:
515   ReverseBytesINode(Node *c, Node *in1) : Node(c, in1) {}
516   virtual int Opcode() const;
517   const Type *bottom_type() const { return TypeInt::INT; }
518   virtual uint ideal_reg() const { return Op_RegI; }
519 };
520 
521 //-------------------------------ReverseBytesLNode--------------------------------
522 // reverse bytes of a long
523 class ReverseBytesLNode : public Node {
524 public:
525   ReverseBytesLNode(Node *c, Node *in1) : Node(c, in1) {}
526   virtual int Opcode() const;
527   const Type *bottom_type() const { return TypeLong::LONG; }
528   virtual uint ideal_reg() const { return Op_RegL; }
529 };
530 
531 //-------------------------------ReverseBytesUSNode--------------------------------
532 // reverse bytes of an unsigned short / char
533 class ReverseBytesUSNode : public Node {
534 public:
535   ReverseBytesUSNode(Node *c, Node *in1) : Node(c, in1) {}
536   virtual int Opcode() const;
537   const Type *bottom_type() const { return TypeInt::CHAR; }
538   virtual uint ideal_reg() const { return Op_RegI; }
539 };
540 
541 //-------------------------------ReverseBytesSNode--------------------------------
542 // reverse bytes of a short
543 class ReverseBytesSNode : public Node {
544 public:
545   ReverseBytesSNode(Node *c, Node *in1) : Node(c, in1) {}
546   virtual int Opcode() const;
547   const Type *bottom_type() const { return TypeInt::SHORT; }
548   virtual uint ideal_reg() const { return Op_RegI; }
549 };
550 
551 #endif // SHARE_OPTO_SUBNODE_HPP