1 /*
   2  * Copyright (c) 2014, 2015, 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 NULL;
 114 }
 115 
 116 //------------------------------Identity---------------------------------------
 117 // Int's can be converted to doubles with no loss of bits.  Hence
 118 // converting an integer to a double and back to an integer is a NOP.
 119 Node* ConvD2INode::Identity(PhaseGVN* phase) {
 120   return (in(1)->Opcode() == Op_ConvI2D) ? in(1)->in(1) : this;
 121 }
 122 
 123 //=============================================================================
 124 //------------------------------Value------------------------------------------
 125 const Type* ConvD2LNode::Value(PhaseGVN* phase) const {
 126   const Type *t = phase->type( in(1) );
 127   if( t == Type::TOP ) return Type::TOP;
 128   if( t == Type::DOUBLE ) return TypeLong::LONG;
 129   const TypeD *td = t->is_double_constant();
 130   return TypeLong::make( SharedRuntime::d2l( td->getd() ) );
 131 }
 132 
 133 //------------------------------Identity---------------------------------------
 134 Node* ConvD2LNode::Identity(PhaseGVN* phase) {
 135   // Remove ConvD2L->ConvL2D->ConvD2L sequences.
 136   if( in(1)       ->Opcode() == Op_ConvL2D &&
 137      in(1)->in(1)->Opcode() == Op_ConvD2L )
 138   return in(1)->in(1);
 139   return this;
 140 }
 141 
 142 //------------------------------Ideal------------------------------------------
 143 // If converting to an int type, skip any rounding nodes
 144 Node *ConvD2LNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 145   if( in(1)->Opcode() == Op_RoundDouble )
 146   set_req(1,in(1)->in(1));
 147   return NULL;
 148 }
 149 
 150 //=============================================================================
 151 //------------------------------Value------------------------------------------
 152 const Type* ConvF2DNode::Value(PhaseGVN* phase) const {
 153   const Type *t = phase->type( in(1) );
 154   if( t == Type::TOP ) return Type::TOP;
 155   if( t == Type::FLOAT ) return Type::DOUBLE;
 156   const TypeF *tf = t->is_float_constant();
 157   return TypeD::make( (double)tf->getf() );
 158 }
 159 
 160 //=============================================================================
 161 //------------------------------Value------------------------------------------
 162 const Type* ConvF2INode::Value(PhaseGVN* phase) const {
 163   const Type *t = phase->type( in(1) );
 164   if( t == Type::TOP )       return Type::TOP;
 165   if( t == Type::FLOAT ) return TypeInt::INT;
 166   const TypeF *tf = t->is_float_constant();
 167   return TypeInt::make( SharedRuntime::f2i( tf->getf() ) );
 168 }
 169 
 170 //------------------------------Identity---------------------------------------
 171 Node* ConvF2INode::Identity(PhaseGVN* phase) {
 172   // Remove ConvF2I->ConvI2F->ConvF2I sequences.
 173   if( in(1)       ->Opcode() == Op_ConvI2F &&
 174      in(1)->in(1)->Opcode() == Op_ConvF2I )
 175   return in(1)->in(1);
 176   return this;
 177 }
 178 
 179 //------------------------------Ideal------------------------------------------
 180 // If converting to an int type, skip any rounding nodes
 181 Node *ConvF2INode::Ideal(PhaseGVN *phase, bool can_reshape) {
 182   if( in(1)->Opcode() == Op_RoundFloat )
 183   set_req(1,in(1)->in(1));
 184   return NULL;
 185 }
 186 
 187 //=============================================================================
 188 //------------------------------Value------------------------------------------
 189 const Type* ConvF2LNode::Value(PhaseGVN* phase) const {
 190   const Type *t = phase->type( in(1) );
 191   if( t == Type::TOP )       return Type::TOP;
 192   if( t == Type::FLOAT ) return TypeLong::LONG;
 193   const TypeF *tf = t->is_float_constant();
 194   return TypeLong::make( SharedRuntime::f2l( tf->getf() ) );
 195 }
 196 
 197 //------------------------------Identity---------------------------------------
 198 Node* ConvF2LNode::Identity(PhaseGVN* phase) {
 199   // Remove ConvF2L->ConvL2F->ConvF2L sequences.
 200   if( in(1)       ->Opcode() == Op_ConvL2F &&
 201      in(1)->in(1)->Opcode() == Op_ConvF2L )
 202   return in(1)->in(1);
 203   return this;
 204 }
 205 
 206 //------------------------------Ideal------------------------------------------
 207 // If converting to an int type, skip any rounding nodes
 208 Node *ConvF2LNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 209   if( in(1)->Opcode() == Op_RoundFloat )
 210   set_req(1,in(1)->in(1));
 211   return NULL;
 212 }
 213 
 214 //=============================================================================
 215 //------------------------------Value------------------------------------------
 216 const Type* ConvI2DNode::Value(PhaseGVN* phase) const {
 217   const Type *t = phase->type( in(1) );
 218   if( t == Type::TOP ) return Type::TOP;
 219   const TypeInt *ti = t->is_int();
 220   if( ti->is_con() ) return TypeD::make( (double)ti->get_con() );
 221   return bottom_type();
 222 }
 223 
 224 //=============================================================================
 225 //------------------------------Value------------------------------------------
 226 const Type* ConvI2FNode::Value(PhaseGVN* phase) const {
 227   const Type *t = phase->type( in(1) );
 228   if( t == Type::TOP ) return Type::TOP;
 229   const TypeInt *ti = t->is_int();
 230   if( ti->is_con() ) return TypeF::make( (float)ti->get_con() );
 231   return bottom_type();
 232 }
 233 
 234 //------------------------------Identity---------------------------------------
 235 Node* ConvI2FNode::Identity(PhaseGVN* phase) {
 236   // Remove ConvI2F->ConvF2I->ConvI2F sequences.
 237   if( in(1)       ->Opcode() == Op_ConvF2I &&
 238      in(1)->in(1)->Opcode() == Op_ConvI2F )
 239   return in(1)->in(1);
 240   return this;
 241 }
 242 
 243 //=============================================================================
 244 //------------------------------Value------------------------------------------
 245 const Type* ConvI2LNode::Value(PhaseGVN* phase) const {
 246   const Type *t = phase->type( in(1) );
 247   if( t == Type::TOP ) return Type::TOP;
 248   const TypeInt *ti = t->is_int();
 249   const Type* tl = TypeLong::make(ti->_lo, ti->_hi, ti->_widen);
 250   // Join my declared type against my incoming type.
 251   tl = tl->filter(_type);
 252   return tl;
 253 }
 254 
 255 #ifdef _LP64
 256 static inline bool long_ranges_overlap(jlong lo1, jlong hi1,
 257                                        jlong lo2, jlong hi2) {
 258   // Two ranges overlap iff one range's low point falls in the other range.
 259   return (lo2 <= lo1 && lo1 <= hi2) || (lo1 <= lo2 && lo2 <= hi1);
 260 }
 261 #endif
 262 
 263 //------------------------------Ideal------------------------------------------
 264 Node *ConvI2LNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 265   const TypeLong* this_type = this->type()->is_long();
 266   Node* this_changed = NULL;
 267 
 268   // If _major_progress, then more loop optimizations follow.  Do NOT
 269   // remove this node's type assertion until no more loop ops can happen.
 270   // The progress bit is set in the major loop optimizations THEN comes the
 271   // call to IterGVN and any chance of hitting this code.  Cf. Opaque1Node.
 272   if (can_reshape && !phase->C->major_progress()) {
 273     const TypeInt* in_type = phase->type(in(1))->isa_int();
 274     if (in_type != NULL && this_type != NULL &&
 275         (in_type->_lo != this_type->_lo ||
 276          in_type->_hi != this_type->_hi)) {
 277           // Although this WORSENS the type, it increases GVN opportunities,
 278           // because I2L nodes with the same input will common up, regardless
 279           // of slightly differing type assertions.  Such slight differences
 280           // arise routinely as a result of loop unrolling, so this is a
 281           // post-unrolling graph cleanup.  Choose a type which depends only
 282           // on my input.  (Exception:  Keep a range assertion of >=0 or <0.)
 283           jlong lo1 = this_type->_lo;
 284           jlong hi1 = this_type->_hi;
 285           int   w1  = this_type->_widen;
 286           if (lo1 != (jint)lo1 ||
 287               hi1 != (jint)hi1 ||
 288               lo1 > hi1) {
 289             // Overflow leads to wraparound, wraparound leads to range saturation.
 290             lo1 = min_jint; hi1 = max_jint;
 291           } else if (lo1 >= 0) {
 292             // Keep a range assertion of >=0.
 293             lo1 = 0;        hi1 = max_jint;
 294           } else if (hi1 < 0) {
 295             // Keep a range assertion of <0.
 296             lo1 = min_jint; hi1 = -1;
 297           } else {
 298             lo1 = min_jint; hi1 = max_jint;
 299           }
 300           const TypeLong* wtype = TypeLong::make(MAX2((jlong)in_type->_lo, lo1),
 301                                                  MIN2((jlong)in_type->_hi, hi1),
 302                                                  MAX2((int)in_type->_widen, w1));
 303           if (wtype != type()) {
 304             set_type(wtype);
 305             // Note: this_type still has old type value, for the logic below.
 306             this_changed = this;
 307           }
 308         }
 309   }
 310 
 311 #ifdef _LP64
 312   // Convert ConvI2L(AddI(x, y)) to AddL(ConvI2L(x), ConvI2L(y))
 313   // but only if x and y have subranges that cannot cause 32-bit overflow,
 314   // under the assumption that x+y is in my own subrange this->type().
 315 
 316   // This assumption is based on a constraint (i.e., type assertion)
 317   // established in Parse::array_addressing or perhaps elsewhere.
 318   // This constraint has been adjoined to the "natural" type of
 319   // the incoming argument in(0).  We know (because of runtime
 320   // checks) - that the result value I2L(x+y) is in the joined range.
 321   // Hence we can restrict the incoming terms (x, y) to values such
 322   // that their sum also lands in that range.
 323 
 324   // This optimization is useful only on 64-bit systems, where we hope
 325   // the addition will end up subsumed in an addressing mode.
 326   // It is necessary to do this when optimizing an unrolled array
 327   // copy loop such as x[i++] = y[i++].
 328 
 329   // On 32-bit systems, it's better to perform as much 32-bit math as
 330   // possible before the I2L conversion, because 32-bit math is cheaper.
 331   // There's no common reason to "leak" a constant offset through the I2L.
 332   // Addressing arithmetic will not absorb it as part of a 64-bit AddL.
 333 
 334   Node* z = in(1);
 335   int op = z->Opcode();
 336   if (op == Op_AddI || op == Op_SubI) {
 337     Node* x = z->in(1);
 338     Node* y = z->in(2);
 339     assert (x != z && y != z, "dead loop in ConvI2LNode::Ideal");
 340     if (phase->type(x) == Type::TOP)  return this_changed;
 341     if (phase->type(y) == Type::TOP)  return this_changed;
 342     const TypeInt*  tx = phase->type(x)->is_int();
 343     const TypeInt*  ty = phase->type(y)->is_int();
 344     const TypeLong* tz = this_type;
 345     jlong xlo = tx->_lo;
 346     jlong xhi = tx->_hi;
 347     jlong ylo = ty->_lo;
 348     jlong yhi = ty->_hi;
 349     jlong zlo = tz->_lo;
 350     jlong zhi = tz->_hi;
 351     jlong vbit = CONST64(1) << BitsPerInt;
 352     int widen =  MAX2(tx->_widen, ty->_widen);
 353     if (op == Op_SubI) {
 354       jlong ylo0 = ylo;
 355       ylo = -yhi;
 356       yhi = -ylo0;
 357     }
 358     // See if x+y can cause positive overflow into z+2**32
 359     if (long_ranges_overlap(xlo+ylo, xhi+yhi, zlo+vbit, zhi+vbit)) {
 360       return this_changed;
 361     }
 362     // See if x+y can cause negative overflow into z-2**32
 363     if (long_ranges_overlap(xlo+ylo, xhi+yhi, zlo-vbit, zhi-vbit)) {
 364       return this_changed;
 365     }
 366     // Now it's always safe to assume x+y does not overflow.
 367     // This is true even if some pairs x,y might cause overflow, as long
 368     // as that overflow value cannot fall into [zlo,zhi].
 369 
 370     // Confident that the arithmetic is "as if infinite precision",
 371     // we can now use z's range to put constraints on those of x and y.
 372     // The "natural" range of x [xlo,xhi] can perhaps be narrowed to a
 373     // more "restricted" range by intersecting [xlo,xhi] with the
 374     // range obtained by subtracting y's range from the asserted range
 375     // of the I2L conversion.  Here's the interval arithmetic algebra:
 376     //    x == z-y == [zlo,zhi]-[ylo,yhi] == [zlo,zhi]+[-yhi,-ylo]
 377     //    => x in [zlo-yhi, zhi-ylo]
 378     //    => x in [zlo-yhi, zhi-ylo] INTERSECT [xlo,xhi]
 379     //    => x in [xlo MAX zlo-yhi, xhi MIN zhi-ylo]
 380     jlong rxlo = MAX2(xlo, zlo - yhi);
 381     jlong rxhi = MIN2(xhi, zhi - ylo);
 382     // And similarly, x changing place with y:
 383     jlong rylo = MAX2(ylo, zlo - xhi);
 384     jlong ryhi = MIN2(yhi, zhi - xlo);
 385     if (rxlo > rxhi || rylo > ryhi) {
 386       return this_changed;  // x or y is dying; don't mess w/ it
 387     }
 388     if (op == Op_SubI) {
 389       jlong rylo0 = rylo;
 390       rylo = -ryhi;
 391       ryhi = -rylo0;
 392     }
 393     assert(rxlo == (int)rxlo && rxhi == (int)rxhi, "x should not overflow");
 394     assert(rylo == (int)rylo && ryhi == (int)ryhi, "y should not overflow");
 395     Node* cx = phase->C->constrained_convI2L(phase, x, TypeInt::make(rxlo, rxhi, widen), NULL);
 396     Node* cy = phase->C->constrained_convI2L(phase, y, TypeInt::make(rylo, ryhi, widen), NULL);
 397     switch (op) {
 398       case Op_AddI:  return new AddLNode(cx, cy);
 399       case Op_SubI:  return new SubLNode(cx, cy);
 400       default:       ShouldNotReachHere();
 401     }
 402   }
 403 #endif //_LP64
 404 
 405   return this_changed;
 406 }
 407 
 408 //=============================================================================
 409 //------------------------------Value------------------------------------------
 410 const Type* ConvL2DNode::Value(PhaseGVN* phase) const {
 411   const Type *t = phase->type( in(1) );
 412   if( t == Type::TOP ) return Type::TOP;
 413   const TypeLong *tl = t->is_long();
 414   if( tl->is_con() ) return TypeD::make( (double)tl->get_con() );
 415   return bottom_type();
 416 }
 417 
 418 //=============================================================================
 419 //------------------------------Value------------------------------------------
 420 const Type* ConvL2FNode::Value(PhaseGVN* phase) const {
 421   const Type *t = phase->type( in(1) );
 422   if( t == Type::TOP ) return Type::TOP;
 423   const TypeLong *tl = t->is_long();
 424   if( tl->is_con() ) return TypeF::make( (float)tl->get_con() );
 425   return bottom_type();
 426 }
 427 
 428 //=============================================================================
 429 //----------------------------Identity-----------------------------------------
 430 Node* ConvL2INode::Identity(PhaseGVN* phase) {
 431   // Convert L2I(I2L(x)) => x
 432   if (in(1)->Opcode() == Op_ConvI2L)  return in(1)->in(1);
 433   return this;
 434 }
 435 
 436 //------------------------------Value------------------------------------------
 437 const Type* ConvL2INode::Value(PhaseGVN* phase) const {
 438   const Type *t = phase->type( in(1) );
 439   if( t == Type::TOP ) return Type::TOP;
 440   const TypeLong *tl = t->is_long();
 441   if (tl->is_con())
 442   // Easy case.
 443   return TypeInt::make((jint)tl->get_con());
 444   return bottom_type();
 445 }
 446 
 447 //------------------------------Ideal------------------------------------------
 448 // Return a node which is more "ideal" than the current node.
 449 // Blow off prior masking to int
 450 Node *ConvL2INode::Ideal(PhaseGVN *phase, bool can_reshape) {
 451   Node *andl = in(1);
 452   uint andl_op = andl->Opcode();
 453   if( andl_op == Op_AndL ) {
 454     // Blow off prior masking to int
 455     if( phase->type(andl->in(2)) == TypeLong::make( 0xFFFFFFFF ) ) {
 456       set_req(1,andl->in(1));
 457       return this;
 458     }
 459   }
 460 
 461   // Swap with a prior add: convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
 462   // This replaces an 'AddL' with an 'AddI'.
 463   if( andl_op == Op_AddL ) {
 464     // Don't do this for nodes which have more than one user since
 465     // we'll end up computing the long add anyway.
 466     if (andl->outcnt() > 1) return NULL;
 467 
 468     Node* x = andl->in(1);
 469     Node* y = andl->in(2);
 470     assert( x != andl && y != andl, "dead loop in ConvL2INode::Ideal" );
 471     if (phase->type(x) == Type::TOP)  return NULL;
 472     if (phase->type(y) == Type::TOP)  return NULL;
 473     Node *add1 = phase->transform(new ConvL2INode(x));
 474     Node *add2 = phase->transform(new ConvL2INode(y));
 475     return new AddINode(add1,add2);
 476   }
 477 
 478   // Disable optimization: LoadL->ConvL2I ==> LoadI.
 479   // It causes problems (sizes of Load and Store nodes do not match)
 480   // in objects initialization code and Escape Analysis.
 481   return NULL;
 482 }
 483 
 484 
 485 
 486 //=============================================================================
 487 //------------------------------Identity---------------------------------------
 488 // Remove redundant roundings
 489 Node* RoundFloatNode::Identity(PhaseGVN* phase) {
 490   assert(Matcher::strict_fp_requires_explicit_rounding, "should only generate for Intel");
 491   // Do not round constants
 492   if (phase->type(in(1))->base() == Type::FloatCon)  return in(1);
 493   int op = in(1)->Opcode();
 494   // Redundant rounding
 495   if( op == Op_RoundFloat ) return in(1);
 496   // Already rounded
 497   if( op == Op_Parm ) return in(1);
 498   if( op == Op_LoadF ) return in(1);
 499   return this;
 500 }
 501 
 502 //------------------------------Value------------------------------------------
 503 const Type* RoundFloatNode::Value(PhaseGVN* phase) const {
 504   return phase->type( in(1) );
 505 }
 506 
 507 //=============================================================================
 508 //------------------------------Identity---------------------------------------
 509 // Remove redundant roundings.  Incoming arguments are already rounded.
 510 Node* RoundDoubleNode::Identity(PhaseGVN* phase) {
 511   assert(Matcher::strict_fp_requires_explicit_rounding, "should only generate for Intel");
 512   // Do not round constants
 513   if (phase->type(in(1))->base() == Type::DoubleCon)  return in(1);
 514   int op = in(1)->Opcode();
 515   // Redundant rounding
 516   if( op == Op_RoundDouble ) return in(1);
 517   // Already rounded
 518   if( op == Op_Parm ) return in(1);
 519   if( op == Op_LoadD ) return in(1);
 520   if( op == Op_ConvF2D ) return in(1);
 521   if( op == Op_ConvI2D ) return in(1);
 522   return this;
 523 }
 524 
 525 //------------------------------Value------------------------------------------
 526 const Type* RoundDoubleNode::Value(PhaseGVN* phase) const {
 527   return phase->type( in(1) );
 528 }
 529 
 530