1 /*
  2  * Copyright (c) 2014, 2019, 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
 21  * questions.
 22  *
 23  */
 24 
 25 #include "precompiled.hpp"
 26 #include "opto/addnode.hpp"
 27 #include "opto/castnode.hpp"
 28 #include "opto/convertnode.hpp"

 29 #include "opto/matcher.hpp"
 30 #include "opto/phaseX.hpp"
 31 #include "opto/subnode.hpp"
 32 #include "runtime/sharedRuntime.hpp"
 33 
 34 //=============================================================================
 35 //------------------------------Identity---------------------------------------
 36 Node* Conv2BNode::Identity(PhaseGVN* phase) {
 37   const Type *t = phase->type( in(1) );
 38   if( t == Type::TOP ) return in(1);
 39   if( t == TypeInt::ZERO ) return in(1);
 40   if( t == TypeInt::ONE ) return in(1);
 41   if( t == TypeInt::BOOL ) return in(1);
 42   return this;
 43 }
 44 
 45 //------------------------------Value------------------------------------------
 46 const Type* Conv2BNode::Value(PhaseGVN* phase) const {
 47   const Type *t = phase->type( in(1) );
 48   if( t == Type::TOP ) return Type::TOP;
 49   if( t == TypeInt::ZERO ) return TypeInt::ZERO;
 50   if( t == TypePtr::NULL_PTR ) return TypeInt::ZERO;
 51   const TypePtr *tp = t->isa_ptr();
 52   if( tp != NULL ) {
 53     if( tp->ptr() == TypePtr::AnyNull ) return Type::TOP;
 54     if( tp->ptr() == TypePtr::Constant) return TypeInt::ONE;
 55     if (tp->ptr() == TypePtr::NotNull)  return TypeInt::ONE;
 56     return TypeInt::BOOL;
 57   }
 58   if (t->base() != Type::Int) return TypeInt::BOOL;
 59   const TypeInt *ti = t->is_int();
 60   if( ti->_hi < 0 || ti->_lo > 0 ) return TypeInt::ONE;
 61   return TypeInt::BOOL;
 62 }
 63 










 64 
 65 // The conversions operations are all Alpha sorted.  Please keep it that way!
 66 //=============================================================================
 67 //------------------------------Value------------------------------------------
 68 const Type* ConvD2FNode::Value(PhaseGVN* phase) const {
 69   const Type *t = phase->type( in(1) );
 70   if( t == Type::TOP ) return Type::TOP;
 71   if( t == Type::DOUBLE ) return Type::FLOAT;
 72   const TypeD *td = t->is_double_constant();
 73   return TypeF::make( (float)td->getd() );
 74 }
 75 
 76 //------------------------------Ideal------------------------------------------
 77 // If we see pattern ConvF2D SomeDoubleOp ConvD2F, do operation as float.
 78 Node *ConvD2FNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 79   if ( in(1)->Opcode() == Op_SqrtD ) {
 80     Node* sqrtd = in(1);
 81     if ( sqrtd->in(1)->Opcode() == Op_ConvF2D ) {
 82       if ( Matcher::match_rule_supported(Op_SqrtF) ) {
 83         Node* convf2d = sqrtd->in(1);
 84         return new SqrtFNode(phase->C, sqrtd->in(0), convf2d->in(1));
 85       }
 86     }
 87   }
 88   return NULL;
 89 }
 90 
 91 //------------------------------Identity---------------------------------------
 92 // Float's can be converted to doubles with no loss of bits.  Hence
 93 // converting a float to a double and back to a float is a NOP.
 94 Node* ConvD2FNode::Identity(PhaseGVN* phase) {
 95   return (in(1)->Opcode() == Op_ConvF2D) ? in(1)->in(1) : this;
 96 }
 97 
 98 //=============================================================================
 99 //------------------------------Value------------------------------------------
100 const Type* ConvD2INode::Value(PhaseGVN* phase) const {
101   const Type *t = phase->type( in(1) );
102   if( t == Type::TOP ) return Type::TOP;
103   if( t == Type::DOUBLE ) return TypeInt::INT;
104   const TypeD *td = t->is_double_constant();
105   return TypeInt::make( SharedRuntime::d2i( td->getd() ) );
106 }
107 
108 //------------------------------Ideal------------------------------------------
109 // If converting to an int type, skip any rounding nodes
110 Node *ConvD2INode::Ideal(PhaseGVN *phase, bool can_reshape) {
111   if (in(1)->Opcode() == Op_RoundDouble) {
112     set_req(1, in(1)->in(1));
113     return this;
114   }
115   return NULL;
116 }
117 
118 //------------------------------Identity---------------------------------------
119 // Int's can be converted to doubles with no loss of bits.  Hence
120 // converting an integer to a double and back to an integer is a NOP.
121 Node* ConvD2INode::Identity(PhaseGVN* phase) {
122   return (in(1)->Opcode() == Op_ConvI2D) ? in(1)->in(1) : this;
123 }
124 
125 //=============================================================================
126 //------------------------------Value------------------------------------------
127 const Type* ConvD2LNode::Value(PhaseGVN* phase) const {
128   const Type *t = phase->type( in(1) );
129   if( t == Type::TOP ) return Type::TOP;
130   if( t == Type::DOUBLE ) return TypeLong::LONG;
131   const TypeD *td = t->is_double_constant();
132   return TypeLong::make( SharedRuntime::d2l( td->getd() ) );
133 }
134 
135 //------------------------------Identity---------------------------------------
136 Node* ConvD2LNode::Identity(PhaseGVN* phase) {
137   // Remove ConvD2L->ConvL2D->ConvD2L sequences.
138   if( in(1)       ->Opcode() == Op_ConvL2D &&
139      in(1)->in(1)->Opcode() == Op_ConvD2L )
140   return in(1)->in(1);
141   return this;
142 }
143 
144 //------------------------------Ideal------------------------------------------
145 // If converting to an int type, skip any rounding nodes
146 Node *ConvD2LNode::Ideal(PhaseGVN *phase, bool can_reshape) {
147   if (in(1)->Opcode() == Op_RoundDouble) {
148     set_req(1, in(1)->in(1));
149     return this;
150   }
151   return NULL;
152 }
153 
154 //=============================================================================
155 //------------------------------Value------------------------------------------
156 const Type* ConvF2DNode::Value(PhaseGVN* phase) const {
157   const Type *t = phase->type( in(1) );
158   if( t == Type::TOP ) return Type::TOP;
159   if( t == Type::FLOAT ) return Type::DOUBLE;
160   const TypeF *tf = t->is_float_constant();
161   return TypeD::make( (double)tf->getf() );
162 }
163 
164 //=============================================================================
165 //------------------------------Value------------------------------------------
166 const Type* ConvF2INode::Value(PhaseGVN* phase) const {
167   const Type *t = phase->type( in(1) );
168   if( t == Type::TOP )       return Type::TOP;
169   if( t == Type::FLOAT ) return TypeInt::INT;
170   const TypeF *tf = t->is_float_constant();
171   return TypeInt::make( SharedRuntime::f2i( tf->getf() ) );
172 }
173 
174 //------------------------------Identity---------------------------------------
175 Node* ConvF2INode::Identity(PhaseGVN* phase) {
176   // Remove ConvF2I->ConvI2F->ConvF2I sequences.
177   if( in(1)       ->Opcode() == Op_ConvI2F &&
178      in(1)->in(1)->Opcode() == Op_ConvF2I )
179   return in(1)->in(1);
180   return this;
181 }
182 
183 //------------------------------Ideal------------------------------------------
184 // If converting to an int type, skip any rounding nodes
185 Node *ConvF2INode::Ideal(PhaseGVN *phase, bool can_reshape) {
186   if (in(1)->Opcode() == Op_RoundFloat) {
187     set_req(1, in(1)->in(1));
188     return this;
189   }
190   return NULL;
191 }
192 
193 //=============================================================================
194 //------------------------------Value------------------------------------------
195 const Type* ConvF2LNode::Value(PhaseGVN* phase) const {
196   const Type *t = phase->type( in(1) );
197   if( t == Type::TOP )       return Type::TOP;
198   if( t == Type::FLOAT ) return TypeLong::LONG;
199   const TypeF *tf = t->is_float_constant();
200   return TypeLong::make( SharedRuntime::f2l( tf->getf() ) );
201 }
202 
203 //------------------------------Identity---------------------------------------
204 Node* ConvF2LNode::Identity(PhaseGVN* phase) {
205   // Remove ConvF2L->ConvL2F->ConvF2L sequences.
206   if( in(1)       ->Opcode() == Op_ConvL2F &&
207      in(1)->in(1)->Opcode() == Op_ConvF2L )
208   return in(1)->in(1);
209   return this;
210 }
211 
212 //------------------------------Ideal------------------------------------------
213 // If converting to an int type, skip any rounding nodes
214 Node *ConvF2LNode::Ideal(PhaseGVN *phase, bool can_reshape) {
215   if (in(1)->Opcode() == Op_RoundFloat) {
216     set_req(1, in(1)->in(1));
217     return this;
218   }
219   return NULL;
220 }
221 
222 //=============================================================================
223 //------------------------------Value------------------------------------------
224 const Type* ConvI2DNode::Value(PhaseGVN* phase) const {
225   const Type *t = phase->type( in(1) );
226   if( t == Type::TOP ) return Type::TOP;
227   const TypeInt *ti = t->is_int();
228   if( ti->is_con() ) return TypeD::make( (double)ti->get_con() );
229   return bottom_type();
230 }
231 
232 //=============================================================================
233 //------------------------------Value------------------------------------------
234 const Type* ConvI2FNode::Value(PhaseGVN* phase) const {
235   const Type *t = phase->type( in(1) );
236   if( t == Type::TOP ) return Type::TOP;
237   const TypeInt *ti = t->is_int();
238   if( ti->is_con() ) return TypeF::make( (float)ti->get_con() );
239   return bottom_type();
240 }
241 
242 //------------------------------Identity---------------------------------------
243 Node* ConvI2FNode::Identity(PhaseGVN* phase) {
244   // Remove ConvI2F->ConvF2I->ConvI2F sequences.
245   if( in(1)       ->Opcode() == Op_ConvF2I &&
246      in(1)->in(1)->Opcode() == Op_ConvI2F )
247   return in(1)->in(1);
248   return this;
249 }
250 
251 //=============================================================================
252 //------------------------------Value------------------------------------------
253 const Type* ConvI2LNode::Value(PhaseGVN* phase) const {
254   const Type *t = phase->type( in(1) );
255   if (t == Type::TOP) {
256     return Type::TOP;
257   }
258   const TypeInt *ti = t->is_int();
259   const Type* tl = TypeLong::make(ti->_lo, ti->_hi, ti->_widen);
260   // Join my declared type against my incoming type.
261   tl = tl->filter(_type);
262   if (!tl->isa_long()) {
263     return tl;
264   }
265   const TypeLong* this_type = tl->is_long();
266   // Do NOT remove this node's type assertion until no more loop ops can happen.
267   if (phase->C->post_loop_opts_phase()) {
268     const TypeInt* in_type = phase->type(in(1))->isa_int();
269     if (in_type != NULL &&
270         (in_type->_lo != this_type->_lo ||
271          in_type->_hi != this_type->_hi)) {
272       // Although this WORSENS the type, it increases GVN opportunities,
273       // because I2L nodes with the same input will common up, regardless
274       // of slightly differing type assertions.  Such slight differences
275       // arise routinely as a result of loop unrolling, so this is a
276       // post-unrolling graph cleanup.  Choose a type which depends only
277       // on my input.  (Exception:  Keep a range assertion of >=0 or <0.)
278       jlong lo1 = this_type->_lo;
279       jlong hi1 = this_type->_hi;
280       int   w1  = this_type->_widen;
281       if (lo1 >= 0) {
282         // Keep a range assertion of >=0.
283         lo1 = 0;        hi1 = max_jint;
284       } else if (hi1 < 0) {
285         // Keep a range assertion of <0.
286         lo1 = min_jint; hi1 = -1;
287       } else {
288         lo1 = min_jint; hi1 = max_jint;
289       }
290       return TypeLong::make(MAX2((jlong)in_type->_lo, lo1),
291                             MIN2((jlong)in_type->_hi, hi1),
292                             MAX2((int)in_type->_widen, w1));
293     }
294   }
295   return this_type;
296 }
297 
298 static inline bool long_ranges_overlap(jlong lo1, jlong hi1,
299                                        jlong lo2, jlong hi2) {
300   // Two ranges overlap iff one range's low point falls in the other range.
301   return (lo2 <= lo1 && lo1 <= hi2) || (lo1 <= lo2 && lo2 <= hi1);
302 }
303 
304 #ifdef _LP64
305 // If there is an existing ConvI2L node with the given parent and type, return
306 // it. Otherwise, create and return a new one. Both reusing existing ConvI2L
307 // nodes and postponing the idealization of new ones are needed to avoid an
308 // explosion of recursive Ideal() calls when compiling long AddI chains.
309 static Node* find_or_make_convI2L(PhaseIterGVN* igvn, Node* parent,
310                                   const TypeLong* type) {
311   Node* n = new ConvI2LNode(parent, type);
312   Node* existing = igvn->hash_find_insert(n);
313   if (existing != NULL) {
314     n->destruct(igvn);
315     return existing;
316   }
317   return igvn->register_new_node_with_optimizer(n);
318 }
319 #endif
320 
321 bool Compile::push_thru_add(PhaseGVN* phase, Node* z, const TypeInteger* tz, const TypeInteger*& rx, const TypeInteger*& ry,
322                             BasicType bt) {
323   int op = z->Opcode();
324   if (op == Op_AddI || op == Op_SubI) {
325     Node* x = z->in(1);
326     Node* y = z->in(2);
327     assert (x != z && y != z, "dead loop in ConvI2LNode::Ideal");
328     if (phase->type(x) == Type::TOP) {
329       return false;
330     }
331     if (phase->type(y) == Type::TOP) {
332       return false;
333     }
334     const TypeInt*  tx = phase->type(x)->is_int();
335     const TypeInt*  ty = phase->type(y)->is_int();
336 
337     jlong xlo = tx->is_int()->_lo;
338     jlong xhi = tx->is_int()->_hi;
339     jlong ylo = ty->is_int()->_lo;
340     jlong yhi = ty->is_int()->_hi;
341     jlong zlo = tz->lo_as_long();
342     jlong zhi = tz->hi_as_long();
343     jlong vbit = CONST64(1) << BitsPerInt;
344     int widen =  MAX2(tx->_widen, ty->_widen);
345     if (op == Op_SubI) {
346       jlong ylo0 = ylo;
347       ylo = -yhi;
348       yhi = -ylo0;
349     }
350     // See if x+y can cause positive overflow into z+2**32
351     if (long_ranges_overlap(xlo+ylo, xhi+yhi, zlo+vbit, zhi+vbit)) {
352       return false;
353     }
354     // See if x+y can cause negative overflow into z-2**32
355     if (long_ranges_overlap(xlo+ylo, xhi+yhi, zlo-vbit, zhi-vbit)) {
356       return false;
357     }
358     // Now it's always safe to assume x+y does not overflow.
359     // This is true even if some pairs x,y might cause overflow, as long
360     // as that overflow value cannot fall into [zlo,zhi].
361 
362     // Confident that the arithmetic is "as if infinite precision",
363     // we can now use z's range to put constraints on those of x and y.
364     // The "natural" range of x [xlo,xhi] can perhaps be narrowed to a
365     // more "restricted" range by intersecting [xlo,xhi] with the
366     // range obtained by subtracting y's range from the asserted range
367     // of the I2L conversion.  Here's the interval arithmetic algebra:
368     //    x == z-y == [zlo,zhi]-[ylo,yhi] == [zlo,zhi]+[-yhi,-ylo]
369     //    => x in [zlo-yhi, zhi-ylo]
370     //    => x in [zlo-yhi, zhi-ylo] INTERSECT [xlo,xhi]
371     //    => x in [xlo MAX zlo-yhi, xhi MIN zhi-ylo]
372     jlong rxlo = MAX2(xlo, zlo - yhi);
373     jlong rxhi = MIN2(xhi, zhi - ylo);
374     // And similarly, x changing place with y:
375     jlong rylo = MAX2(ylo, zlo - xhi);
376     jlong ryhi = MIN2(yhi, zhi - xlo);
377     if (rxlo > rxhi || rylo > ryhi) {
378       return false;  // x or y is dying; don't mess w/ it
379     }
380     if (op == Op_SubI) {
381       jlong rylo0 = rylo;
382       rylo = -ryhi;
383       ryhi = -rylo0;
384     }
385     assert(rxlo == (int)rxlo && rxhi == (int)rxhi, "x should not overflow");
386     assert(rylo == (int)rylo && ryhi == (int)ryhi, "y should not overflow");
387     rx = TypeInteger::make(rxlo, rxhi, widen, bt);
388     ry = TypeInteger::make(rylo, ryhi, widen, bt);
389     return true;
390   }
391   return false;
392 }
393 
394 
395 //------------------------------Ideal------------------------------------------
396 Node *ConvI2LNode::Ideal(PhaseGVN *phase, bool can_reshape) {
397   const TypeLong* this_type = this->type()->is_long();
398   if (can_reshape && !phase->C->post_loop_opts_phase()) {
399     // makes sure we run ::Value to potentially remove type assertion after loop opts
400     phase->C->record_for_post_loop_opts_igvn(this);
401   }
402 #ifdef _LP64
403   // Convert ConvI2L(AddI(x, y)) to AddL(ConvI2L(x), ConvI2L(y))
404   // but only if x and y have subranges that cannot cause 32-bit overflow,
405   // under the assumption that x+y is in my own subrange this->type().
406 
407   // This assumption is based on a constraint (i.e., type assertion)
408   // established in Parse::array_addressing or perhaps elsewhere.
409   // This constraint has been adjoined to the "natural" type of
410   // the incoming argument in(0).  We know (because of runtime
411   // checks) - that the result value I2L(x+y) is in the joined range.
412   // Hence we can restrict the incoming terms (x, y) to values such
413   // that their sum also lands in that range.
414 
415   // This optimization is useful only on 64-bit systems, where we hope
416   // the addition will end up subsumed in an addressing mode.
417   // It is necessary to do this when optimizing an unrolled array
418   // copy loop such as x[i++] = y[i++].
419 
420   // On 32-bit systems, it's better to perform as much 32-bit math as
421   // possible before the I2L conversion, because 32-bit math is cheaper.
422   // There's no common reason to "leak" a constant offset through the I2L.
423   // Addressing arithmetic will not absorb it as part of a 64-bit AddL.
424   PhaseIterGVN* igvn = phase->is_IterGVN();
425   Node* z = in(1);
426   const TypeInteger* rx = NULL;
427   const TypeInteger* ry = NULL;
428   if (Compile::push_thru_add(phase, z, this_type, rx, ry, T_LONG)) {
429     if (igvn == NULL) {
430       // Postpone this optimization to iterative GVN, where we can handle deep
431       // AddI chains without an exponential number of recursive Ideal() calls.
432       phase->record_for_igvn(this);
433       return NULL;
434     }
435     int op = z->Opcode();
436     Node* x = z->in(1);
437     Node* y = z->in(2);
438 
439     Node* cx = find_or_make_convI2L(igvn, x, rx->is_long());
440     Node* cy = find_or_make_convI2L(igvn, y, ry->is_long());
441     switch (op) {
442       case Op_AddI:  return new AddLNode(cx, cy);
443       case Op_SubI:  return new SubLNode(cx, cy);
444       default:       ShouldNotReachHere();
445     }
446   }
447 #endif //_LP64
448 
449   return NULL;
450 }
451 
452 //=============================================================================
453 //------------------------------Value------------------------------------------
454 const Type* ConvL2DNode::Value(PhaseGVN* phase) const {
455   const Type *t = phase->type( in(1) );
456   if( t == Type::TOP ) return Type::TOP;
457   const TypeLong *tl = t->is_long();
458   if( tl->is_con() ) return TypeD::make( (double)tl->get_con() );
459   return bottom_type();
460 }
461 
462 //=============================================================================
463 //------------------------------Value------------------------------------------
464 const Type* ConvL2FNode::Value(PhaseGVN* phase) const {
465   const Type *t = phase->type( in(1) );
466   if( t == Type::TOP ) return Type::TOP;
467   const TypeLong *tl = t->is_long();
468   if( tl->is_con() ) return TypeF::make( (float)tl->get_con() );
469   return bottom_type();
470 }
471 
472 //=============================================================================
473 //----------------------------Identity-----------------------------------------
474 Node* ConvL2INode::Identity(PhaseGVN* phase) {
475   // Convert L2I(I2L(x)) => x
476   if (in(1)->Opcode() == Op_ConvI2L)  return in(1)->in(1);
477   return this;
478 }
479 
480 //------------------------------Value------------------------------------------
481 const Type* ConvL2INode::Value(PhaseGVN* phase) const {
482   const Type *t = phase->type( in(1) );
483   if( t == Type::TOP ) return Type::TOP;
484   const TypeLong *tl = t->is_long();
485   const TypeInt* ti = TypeInt::INT;
486   if (tl->is_con()) {
487     // Easy case.
488     ti = TypeInt::make((jint)tl->get_con());
489   } else if (tl->_lo >= min_jint && tl->_hi <= max_jint) {
490     ti = TypeInt::make((jint)tl->_lo, (jint)tl->_hi, tl->_widen);
491   }
492   return ti->filter(_type);
493 }
494 
495 //------------------------------Ideal------------------------------------------
496 // Return a node which is more "ideal" than the current node.
497 // Blow off prior masking to int
498 Node *ConvL2INode::Ideal(PhaseGVN *phase, bool can_reshape) {
499   Node *andl = in(1);
500   uint andl_op = andl->Opcode();
501   if( andl_op == Op_AndL ) {
502     // Blow off prior masking to int
503     if( phase->type(andl->in(2)) == TypeLong::make( 0xFFFFFFFF ) ) {
504       set_req_X(1,andl->in(1), phase);
505       return this;
506     }
507   }
508 
509   // Swap with a prior add: convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
510   // This replaces an 'AddL' with an 'AddI'.
511   if( andl_op == Op_AddL ) {
512     // Don't do this for nodes which have more than one user since
513     // we'll end up computing the long add anyway.
514     if (andl->outcnt() > 1) return NULL;
515 
516     Node* x = andl->in(1);
517     Node* y = andl->in(2);
518     assert( x != andl && y != andl, "dead loop in ConvL2INode::Ideal" );
519     if (phase->type(x) == Type::TOP)  return NULL;
520     if (phase->type(y) == Type::TOP)  return NULL;
521     Node *add1 = phase->transform(new ConvL2INode(x));
522     Node *add2 = phase->transform(new ConvL2INode(y));
523     return new AddINode(add1,add2);
524   }
525 
526   // Disable optimization: LoadL->ConvL2I ==> LoadI.
527   // It causes problems (sizes of Load and Store nodes do not match)
528   // in objects initialization code and Escape Analysis.
529   return NULL;
530 }
531 
532 
533 
534 //=============================================================================
535 //------------------------------Identity---------------------------------------
536 // Remove redundant roundings
537 Node* RoundFloatNode::Identity(PhaseGVN* phase) {
538   assert(Matcher::strict_fp_requires_explicit_rounding, "should only generate for Intel");
539   // Do not round constants
540   if (phase->type(in(1))->base() == Type::FloatCon)  return in(1);
541   int op = in(1)->Opcode();
542   // Redundant rounding
543   if( op == Op_RoundFloat ) return in(1);
544   // Already rounded
545   if( op == Op_Parm ) return in(1);
546   if( op == Op_LoadF ) return in(1);
547   return this;
548 }
549 
550 //------------------------------Value------------------------------------------
551 const Type* RoundFloatNode::Value(PhaseGVN* phase) const {
552   return phase->type( in(1) );
553 }
554 
555 //=============================================================================
556 //------------------------------Identity---------------------------------------
557 // Remove redundant roundings.  Incoming arguments are already rounded.
558 Node* RoundDoubleNode::Identity(PhaseGVN* phase) {
559   assert(Matcher::strict_fp_requires_explicit_rounding, "should only generate for Intel");
560   // Do not round constants
561   if (phase->type(in(1))->base() == Type::DoubleCon)  return in(1);
562   int op = in(1)->Opcode();
563   // Redundant rounding
564   if( op == Op_RoundDouble ) return in(1);
565   // Already rounded
566   if( op == Op_Parm ) return in(1);
567   if( op == Op_LoadD ) return in(1);
568   if( op == Op_ConvF2D ) return in(1);
569   if( op == Op_ConvI2D ) return in(1);
570   return this;
571 }
572 
573 //------------------------------Value------------------------------------------
574 const Type* RoundDoubleNode::Value(PhaseGVN* phase) const {
575   return phase->type( in(1) );
576 }
577 
578 //=============================================================================
579 RoundDoubleModeNode* RoundDoubleModeNode::make(PhaseGVN& gvn, Node* arg, RoundDoubleModeNode::RoundingMode rmode) {
580   ConINode* rm = gvn.intcon(rmode);
581   return new RoundDoubleModeNode(arg, (Node *)rm);
582 }
583 
584 //------------------------------Identity---------------------------------------
585 // Remove redundant roundings.
586 Node* RoundDoubleModeNode::Identity(PhaseGVN* phase) {
587   int op = in(1)->Opcode();
588   // Redundant rounding e.g. floor(ceil(n)) -> ceil(n)
589   if(op == Op_RoundDoubleMode) return in(1);
590   return this;
591 }
592 const Type* RoundDoubleModeNode::Value(PhaseGVN* phase) const {
593   return Type::DOUBLE;
594 }
595 //=============================================================================
--- EOF ---