src/share/vm/opto/divnode.cpp

Mon, 27 May 2013 12:56:34 +0200

author
stefank
date
Mon, 27 May 2013 12:56:34 +0200
changeset 5195
95c00927be11
parent 4153
b9a9ed0f8eeb
child 6876
710a3c8b516e
child 9614
bb44c0e88235
permissions
-rw-r--r--

8015428: Remove unused CDS support from StringTable
Summary: The string in StringTable is not used by CDS anymore. Remove the unnecessary code in preparation for 8015422: Large performance hit when the StringTable is walked twice in Parallel Scavenge
Reviewed-by: pliden, tschatzl, coleenp

     1 /*
     2  * Copyright (c) 1997, 2012, 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  */
    25 #include "precompiled.hpp"
    26 #include "memory/allocation.inline.hpp"
    27 #include "opto/addnode.hpp"
    28 #include "opto/connode.hpp"
    29 #include "opto/divnode.hpp"
    30 #include "opto/machnode.hpp"
    31 #include "opto/matcher.hpp"
    32 #include "opto/mulnode.hpp"
    33 #include "opto/phaseX.hpp"
    34 #include "opto/subnode.hpp"
    36 // Portions of code courtesy of Clifford Click
    38 // Optimization - Graph Style
    40 #include <math.h>
    42 //----------------------magic_int_divide_constants-----------------------------
    43 // Compute magic multiplier and shift constant for converting a 32 bit divide
    44 // by constant into a multiply/shift/add series. Return false if calculations
    45 // fail.
    46 //
    47 // Borrowed almost verbatim from Hacker's Delight by Henry S. Warren, Jr. with
    48 // minor type name and parameter changes.
    49 static bool magic_int_divide_constants(jint d, jint &M, jint &s) {
    50   int32_t p;
    51   uint32_t ad, anc, delta, q1, r1, q2, r2, t;
    52   const uint32_t two31 = 0x80000000L;     // 2**31.
    54   ad = ABS(d);
    55   if (d == 0 || d == 1) return false;
    56   t = two31 + ((uint32_t)d >> 31);
    57   anc = t - 1 - t%ad;     // Absolute value of nc.
    58   p = 31;                 // Init. p.
    59   q1 = two31/anc;         // Init. q1 = 2**p/|nc|.
    60   r1 = two31 - q1*anc;    // Init. r1 = rem(2**p, |nc|).
    61   q2 = two31/ad;          // Init. q2 = 2**p/|d|.
    62   r2 = two31 - q2*ad;     // Init. r2 = rem(2**p, |d|).
    63   do {
    64     p = p + 1;
    65     q1 = 2*q1;            // Update q1 = 2**p/|nc|.
    66     r1 = 2*r1;            // Update r1 = rem(2**p, |nc|).
    67     if (r1 >= anc) {      // (Must be an unsigned
    68       q1 = q1 + 1;        // comparison here).
    69       r1 = r1 - anc;
    70     }
    71     q2 = 2*q2;            // Update q2 = 2**p/|d|.
    72     r2 = 2*r2;            // Update r2 = rem(2**p, |d|).
    73     if (r2 >= ad) {       // (Must be an unsigned
    74       q2 = q2 + 1;        // comparison here).
    75       r2 = r2 - ad;
    76     }
    77     delta = ad - r2;
    78   } while (q1 < delta || (q1 == delta && r1 == 0));
    80   M = q2 + 1;
    81   if (d < 0) M = -M;      // Magic number and
    82   s = p - 32;             // shift amount to return.
    84   return true;
    85 }
    87 //--------------------------transform_int_divide-------------------------------
    88 // Convert a division by constant divisor into an alternate Ideal graph.
    89 // Return NULL if no transformation occurs.
    90 static Node *transform_int_divide( PhaseGVN *phase, Node *dividend, jint divisor ) {
    92   // Check for invalid divisors
    93   assert( divisor != 0 && divisor != min_jint,
    94           "bad divisor for transforming to long multiply" );
    96   bool d_pos = divisor >= 0;
    97   jint d = d_pos ? divisor : -divisor;
    98   const int N = 32;
   100   // Result
   101   Node *q = NULL;
   103   if (d == 1) {
   104     // division by +/- 1
   105     if (!d_pos) {
   106       // Just negate the value
   107       q = new (phase->C) SubINode(phase->intcon(0), dividend);
   108     }
   109   } else if ( is_power_of_2(d) ) {
   110     // division by +/- a power of 2
   112     // See if we can simply do a shift without rounding
   113     bool needs_rounding = true;
   114     const Type *dt = phase->type(dividend);
   115     const TypeInt *dti = dt->isa_int();
   116     if (dti && dti->_lo >= 0) {
   117       // we don't need to round a positive dividend
   118       needs_rounding = false;
   119     } else if( dividend->Opcode() == Op_AndI ) {
   120       // An AND mask of sufficient size clears the low bits and
   121       // I can avoid rounding.
   122       const TypeInt *andconi_t = phase->type( dividend->in(2) )->isa_int();
   123       if( andconi_t && andconi_t->is_con() ) {
   124         jint andconi = andconi_t->get_con();
   125         if( andconi < 0 && is_power_of_2(-andconi) && (-andconi) >= d ) {
   126           if( (-andconi) == d ) // Remove AND if it clears bits which will be shifted
   127             dividend = dividend->in(1);
   128           needs_rounding = false;
   129         }
   130       }
   131     }
   133     // Add rounding to the shift to handle the sign bit
   134     int l = log2_intptr(d-1)+1;
   135     if (needs_rounding) {
   136       // Divide-by-power-of-2 can be made into a shift, but you have to do
   137       // more math for the rounding.  You need to add 0 for positive
   138       // numbers, and "i-1" for negative numbers.  Example: i=4, so the
   139       // shift is by 2.  You need to add 3 to negative dividends and 0 to
   140       // positive ones.  So (-7+3)>>2 becomes -1, (-4+3)>>2 becomes -1,
   141       // (-2+3)>>2 becomes 0, etc.
   143       // Compute 0 or -1, based on sign bit
   144       Node *sign = phase->transform(new (phase->C) RShiftINode(dividend, phase->intcon(N - 1)));
   145       // Mask sign bit to the low sign bits
   146       Node *round = phase->transform(new (phase->C) URShiftINode(sign, phase->intcon(N - l)));
   147       // Round up before shifting
   148       dividend = phase->transform(new (phase->C) AddINode(dividend, round));
   149     }
   151     // Shift for division
   152     q = new (phase->C) RShiftINode(dividend, phase->intcon(l));
   154     if (!d_pos) {
   155       q = new (phase->C) SubINode(phase->intcon(0), phase->transform(q));
   156     }
   157   } else {
   158     // Attempt the jint constant divide -> multiply transform found in
   159     //   "Division by Invariant Integers using Multiplication"
   160     //     by Granlund and Montgomery
   161     // See also "Hacker's Delight", chapter 10 by Warren.
   163     jint magic_const;
   164     jint shift_const;
   165     if (magic_int_divide_constants(d, magic_const, shift_const)) {
   166       Node *magic = phase->longcon(magic_const);
   167       Node *dividend_long = phase->transform(new (phase->C) ConvI2LNode(dividend));
   169       // Compute the high half of the dividend x magic multiplication
   170       Node *mul_hi = phase->transform(new (phase->C) MulLNode(dividend_long, magic));
   172       if (magic_const < 0) {
   173         mul_hi = phase->transform(new (phase->C) RShiftLNode(mul_hi, phase->intcon(N)));
   174         mul_hi = phase->transform(new (phase->C) ConvL2INode(mul_hi));
   176         // The magic multiplier is too large for a 32 bit constant. We've adjusted
   177         // it down by 2^32, but have to add 1 dividend back in after the multiplication.
   178         // This handles the "overflow" case described by Granlund and Montgomery.
   179         mul_hi = phase->transform(new (phase->C) AddINode(dividend, mul_hi));
   181         // Shift over the (adjusted) mulhi
   182         if (shift_const != 0) {
   183           mul_hi = phase->transform(new (phase->C) RShiftINode(mul_hi, phase->intcon(shift_const)));
   184         }
   185       } else {
   186         // No add is required, we can merge the shifts together.
   187         mul_hi = phase->transform(new (phase->C) RShiftLNode(mul_hi, phase->intcon(N + shift_const)));
   188         mul_hi = phase->transform(new (phase->C) ConvL2INode(mul_hi));
   189       }
   191       // Get a 0 or -1 from the sign of the dividend.
   192       Node *addend0 = mul_hi;
   193       Node *addend1 = phase->transform(new (phase->C) RShiftINode(dividend, phase->intcon(N-1)));
   195       // If the divisor is negative, swap the order of the input addends;
   196       // this has the effect of negating the quotient.
   197       if (!d_pos) {
   198         Node *temp = addend0; addend0 = addend1; addend1 = temp;
   199       }
   201       // Adjust the final quotient by subtracting -1 (adding 1)
   202       // from the mul_hi.
   203       q = new (phase->C) SubINode(addend0, addend1);
   204     }
   205   }
   207   return q;
   208 }
   210 //---------------------magic_long_divide_constants-----------------------------
   211 // Compute magic multiplier and shift constant for converting a 64 bit divide
   212 // by constant into a multiply/shift/add series. Return false if calculations
   213 // fail.
   214 //
   215 // Borrowed almost verbatim from Hacker's Delight by Henry S. Warren, Jr. with
   216 // minor type name and parameter changes.  Adjusted to 64 bit word width.
   217 static bool magic_long_divide_constants(jlong d, jlong &M, jint &s) {
   218   int64_t p;
   219   uint64_t ad, anc, delta, q1, r1, q2, r2, t;
   220   const uint64_t two63 = 0x8000000000000000LL;     // 2**63.
   222   ad = ABS(d);
   223   if (d == 0 || d == 1) return false;
   224   t = two63 + ((uint64_t)d >> 63);
   225   anc = t - 1 - t%ad;     // Absolute value of nc.
   226   p = 63;                 // Init. p.
   227   q1 = two63/anc;         // Init. q1 = 2**p/|nc|.
   228   r1 = two63 - q1*anc;    // Init. r1 = rem(2**p, |nc|).
   229   q2 = two63/ad;          // Init. q2 = 2**p/|d|.
   230   r2 = two63 - q2*ad;     // Init. r2 = rem(2**p, |d|).
   231   do {
   232     p = p + 1;
   233     q1 = 2*q1;            // Update q1 = 2**p/|nc|.
   234     r1 = 2*r1;            // Update r1 = rem(2**p, |nc|).
   235     if (r1 >= anc) {      // (Must be an unsigned
   236       q1 = q1 + 1;        // comparison here).
   237       r1 = r1 - anc;
   238     }
   239     q2 = 2*q2;            // Update q2 = 2**p/|d|.
   240     r2 = 2*r2;            // Update r2 = rem(2**p, |d|).
   241     if (r2 >= ad) {       // (Must be an unsigned
   242       q2 = q2 + 1;        // comparison here).
   243       r2 = r2 - ad;
   244     }
   245     delta = ad - r2;
   246   } while (q1 < delta || (q1 == delta && r1 == 0));
   248   M = q2 + 1;
   249   if (d < 0) M = -M;      // Magic number and
   250   s = p - 64;             // shift amount to return.
   252   return true;
   253 }
   255 //---------------------long_by_long_mulhi--------------------------------------
   256 // Generate ideal node graph for upper half of a 64 bit x 64 bit multiplication
   257 static Node* long_by_long_mulhi(PhaseGVN* phase, Node* dividend, jlong magic_const) {
   258   // If the architecture supports a 64x64 mulhi, there is
   259   // no need to synthesize it in ideal nodes.
   260   if (Matcher::has_match_rule(Op_MulHiL)) {
   261     Node* v = phase->longcon(magic_const);
   262     return new (phase->C) MulHiLNode(dividend, v);
   263   }
   265   // Taken from Hacker's Delight, Fig. 8-2. Multiply high signed.
   266   // (http://www.hackersdelight.org/HDcode/mulhs.c)
   267   //
   268   // int mulhs(int u, int v) {
   269   //    unsigned u0, v0, w0;
   270   //    int u1, v1, w1, w2, t;
   271   //
   272   //    u0 = u & 0xFFFF;  u1 = u >> 16;
   273   //    v0 = v & 0xFFFF;  v1 = v >> 16;
   274   //    w0 = u0*v0;
   275   //    t  = u1*v0 + (w0 >> 16);
   276   //    w1 = t & 0xFFFF;
   277   //    w2 = t >> 16;
   278   //    w1 = u0*v1 + w1;
   279   //    return u1*v1 + w2 + (w1 >> 16);
   280   // }
   281   //
   282   // Note: The version above is for 32x32 multiplications, while the
   283   // following inline comments are adapted to 64x64.
   285   const int N = 64;
   287   // Dummy node to keep intermediate nodes alive during construction
   288   Node* hook = new (phase->C) Node(4);
   290   // u0 = u & 0xFFFFFFFF;  u1 = u >> 32;
   291   Node* u0 = phase->transform(new (phase->C) AndLNode(dividend, phase->longcon(0xFFFFFFFF)));
   292   Node* u1 = phase->transform(new (phase->C) RShiftLNode(dividend, phase->intcon(N / 2)));
   293   hook->init_req(0, u0);
   294   hook->init_req(1, u1);
   296   // v0 = v & 0xFFFFFFFF;  v1 = v >> 32;
   297   Node* v0 = phase->longcon(magic_const & 0xFFFFFFFF);
   298   Node* v1 = phase->longcon(magic_const >> (N / 2));
   300   // w0 = u0*v0;
   301   Node* w0 = phase->transform(new (phase->C) MulLNode(u0, v0));
   303   // t = u1*v0 + (w0 >> 32);
   304   Node* u1v0 = phase->transform(new (phase->C) MulLNode(u1, v0));
   305   Node* temp = phase->transform(new (phase->C) URShiftLNode(w0, phase->intcon(N / 2)));
   306   Node* t    = phase->transform(new (phase->C) AddLNode(u1v0, temp));
   307   hook->init_req(2, t);
   309   // w1 = t & 0xFFFFFFFF;
   310   Node* w1 = phase->transform(new (phase->C) AndLNode(t, phase->longcon(0xFFFFFFFF)));
   311   hook->init_req(3, w1);
   313   // w2 = t >> 32;
   314   Node* w2 = phase->transform(new (phase->C) RShiftLNode(t, phase->intcon(N / 2)));
   316   // w1 = u0*v1 + w1;
   317   Node* u0v1 = phase->transform(new (phase->C) MulLNode(u0, v1));
   318   w1         = phase->transform(new (phase->C) AddLNode(u0v1, w1));
   320   // return u1*v1 + w2 + (w1 >> 32);
   321   Node* u1v1  = phase->transform(new (phase->C) MulLNode(u1, v1));
   322   Node* temp1 = phase->transform(new (phase->C) AddLNode(u1v1, w2));
   323   Node* temp2 = phase->transform(new (phase->C) RShiftLNode(w1, phase->intcon(N / 2)));
   325   // Remove the bogus extra edges used to keep things alive
   326   PhaseIterGVN* igvn = phase->is_IterGVN();
   327   if (igvn != NULL) {
   328     igvn->remove_dead_node(hook);
   329   } else {
   330     for (int i = 0; i < 4; i++) {
   331       hook->set_req(i, NULL);
   332     }
   333   }
   335   return new (phase->C) AddLNode(temp1, temp2);
   336 }
   339 //--------------------------transform_long_divide------------------------------
   340 // Convert a division by constant divisor into an alternate Ideal graph.
   341 // Return NULL if no transformation occurs.
   342 static Node *transform_long_divide( PhaseGVN *phase, Node *dividend, jlong divisor ) {
   343   // Check for invalid divisors
   344   assert( divisor != 0L && divisor != min_jlong,
   345           "bad divisor for transforming to long multiply" );
   347   bool d_pos = divisor >= 0;
   348   jlong d = d_pos ? divisor : -divisor;
   349   const int N = 64;
   351   // Result
   352   Node *q = NULL;
   354   if (d == 1) {
   355     // division by +/- 1
   356     if (!d_pos) {
   357       // Just negate the value
   358       q = new (phase->C) SubLNode(phase->longcon(0), dividend);
   359     }
   360   } else if ( is_power_of_2_long(d) ) {
   362     // division by +/- a power of 2
   364     // See if we can simply do a shift without rounding
   365     bool needs_rounding = true;
   366     const Type *dt = phase->type(dividend);
   367     const TypeLong *dtl = dt->isa_long();
   369     if (dtl && dtl->_lo > 0) {
   370       // we don't need to round a positive dividend
   371       needs_rounding = false;
   372     } else if( dividend->Opcode() == Op_AndL ) {
   373       // An AND mask of sufficient size clears the low bits and
   374       // I can avoid rounding.
   375       const TypeLong *andconl_t = phase->type( dividend->in(2) )->isa_long();
   376       if( andconl_t && andconl_t->is_con() ) {
   377         jlong andconl = andconl_t->get_con();
   378         if( andconl < 0 && is_power_of_2_long(-andconl) && (-andconl) >= d ) {
   379           if( (-andconl) == d ) // Remove AND if it clears bits which will be shifted
   380             dividend = dividend->in(1);
   381           needs_rounding = false;
   382         }
   383       }
   384     }
   386     // Add rounding to the shift to handle the sign bit
   387     int l = log2_long(d-1)+1;
   388     if (needs_rounding) {
   389       // Divide-by-power-of-2 can be made into a shift, but you have to do
   390       // more math for the rounding.  You need to add 0 for positive
   391       // numbers, and "i-1" for negative numbers.  Example: i=4, so the
   392       // shift is by 2.  You need to add 3 to negative dividends and 0 to
   393       // positive ones.  So (-7+3)>>2 becomes -1, (-4+3)>>2 becomes -1,
   394       // (-2+3)>>2 becomes 0, etc.
   396       // Compute 0 or -1, based on sign bit
   397       Node *sign = phase->transform(new (phase->C) RShiftLNode(dividend, phase->intcon(N - 1)));
   398       // Mask sign bit to the low sign bits
   399       Node *round = phase->transform(new (phase->C) URShiftLNode(sign, phase->intcon(N - l)));
   400       // Round up before shifting
   401       dividend = phase->transform(new (phase->C) AddLNode(dividend, round));
   402     }
   404     // Shift for division
   405     q = new (phase->C) RShiftLNode(dividend, phase->intcon(l));
   407     if (!d_pos) {
   408       q = new (phase->C) SubLNode(phase->longcon(0), phase->transform(q));
   409     }
   410   } else if ( !Matcher::use_asm_for_ldiv_by_con(d) ) { // Use hardware DIV instruction when
   411                                                        // it is faster than code generated below.
   412     // Attempt the jlong constant divide -> multiply transform found in
   413     //   "Division by Invariant Integers using Multiplication"
   414     //     by Granlund and Montgomery
   415     // See also "Hacker's Delight", chapter 10 by Warren.
   417     jlong magic_const;
   418     jint shift_const;
   419     if (magic_long_divide_constants(d, magic_const, shift_const)) {
   420       // Compute the high half of the dividend x magic multiplication
   421       Node *mul_hi = phase->transform(long_by_long_mulhi(phase, dividend, magic_const));
   423       // The high half of the 128-bit multiply is computed.
   424       if (magic_const < 0) {
   425         // The magic multiplier is too large for a 64 bit constant. We've adjusted
   426         // it down by 2^64, but have to add 1 dividend back in after the multiplication.
   427         // This handles the "overflow" case described by Granlund and Montgomery.
   428         mul_hi = phase->transform(new (phase->C) AddLNode(dividend, mul_hi));
   429       }
   431       // Shift over the (adjusted) mulhi
   432       if (shift_const != 0) {
   433         mul_hi = phase->transform(new (phase->C) RShiftLNode(mul_hi, phase->intcon(shift_const)));
   434       }
   436       // Get a 0 or -1 from the sign of the dividend.
   437       Node *addend0 = mul_hi;
   438       Node *addend1 = phase->transform(new (phase->C) RShiftLNode(dividend, phase->intcon(N-1)));
   440       // If the divisor is negative, swap the order of the input addends;
   441       // this has the effect of negating the quotient.
   442       if (!d_pos) {
   443         Node *temp = addend0; addend0 = addend1; addend1 = temp;
   444       }
   446       // Adjust the final quotient by subtracting -1 (adding 1)
   447       // from the mul_hi.
   448       q = new (phase->C) SubLNode(addend0, addend1);
   449     }
   450   }
   452   return q;
   453 }
   455 //=============================================================================
   456 //------------------------------Identity---------------------------------------
   457 // If the divisor is 1, we are an identity on the dividend.
   458 Node *DivINode::Identity( PhaseTransform *phase ) {
   459   return (phase->type( in(2) )->higher_equal(TypeInt::ONE)) ? in(1) : this;
   460 }
   462 //------------------------------Idealize---------------------------------------
   463 // Divides can be changed to multiplies and/or shifts
   464 Node *DivINode::Ideal(PhaseGVN *phase, bool can_reshape) {
   465   if (in(0) && remove_dead_region(phase, can_reshape))  return this;
   466   // Don't bother trying to transform a dead node
   467   if( in(0) && in(0)->is_top() )  return NULL;
   469   const Type *t = phase->type( in(2) );
   470   if( t == TypeInt::ONE )       // Identity?
   471     return NULL;                // Skip it
   473   const TypeInt *ti = t->isa_int();
   474   if( !ti ) return NULL;
   475   if( !ti->is_con() ) return NULL;
   476   jint i = ti->get_con();       // Get divisor
   478   if (i == 0) return NULL;      // Dividing by zero constant does not idealize
   480   set_req(0,NULL);              // Dividing by a not-zero constant; no faulting
   482   // Dividing by MININT does not optimize as a power-of-2 shift.
   483   if( i == min_jint ) return NULL;
   485   return transform_int_divide( phase, in(1), i );
   486 }
   488 //------------------------------Value------------------------------------------
   489 // A DivINode divides its inputs.  The third input is a Control input, used to
   490 // prevent hoisting the divide above an unsafe test.
   491 const Type *DivINode::Value( PhaseTransform *phase ) const {
   492   // Either input is TOP ==> the result is TOP
   493   const Type *t1 = phase->type( in(1) );
   494   const Type *t2 = phase->type( in(2) );
   495   if( t1 == Type::TOP ) return Type::TOP;
   496   if( t2 == Type::TOP ) return Type::TOP;
   498   // x/x == 1 since we always generate the dynamic divisor check for 0.
   499   if( phase->eqv( in(1), in(2) ) )
   500     return TypeInt::ONE;
   502   // Either input is BOTTOM ==> the result is the local BOTTOM
   503   const Type *bot = bottom_type();
   504   if( (t1 == bot) || (t2 == bot) ||
   505       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
   506     return bot;
   508   // Divide the two numbers.  We approximate.
   509   // If divisor is a constant and not zero
   510   const TypeInt *i1 = t1->is_int();
   511   const TypeInt *i2 = t2->is_int();
   512   int widen = MAX2(i1->_widen, i2->_widen);
   514   if( i2->is_con() && i2->get_con() != 0 ) {
   515     int32 d = i2->get_con(); // Divisor
   516     jint lo, hi;
   517     if( d >= 0 ) {
   518       lo = i1->_lo/d;
   519       hi = i1->_hi/d;
   520     } else {
   521       if( d == -1 && i1->_lo == min_jint ) {
   522         // 'min_jint/-1' throws arithmetic exception during compilation
   523         lo = min_jint;
   524         // do not support holes, 'hi' must go to either min_jint or max_jint:
   525         // [min_jint, -10]/[-1,-1] ==> [min_jint] UNION [10,max_jint]
   526         hi = i1->_hi == min_jint ? min_jint : max_jint;
   527       } else {
   528         lo = i1->_hi/d;
   529         hi = i1->_lo/d;
   530       }
   531     }
   532     return TypeInt::make(lo, hi, widen);
   533   }
   535   // If the dividend is a constant
   536   if( i1->is_con() ) {
   537     int32 d = i1->get_con();
   538     if( d < 0 ) {
   539       if( d == min_jint ) {
   540         //  (-min_jint) == min_jint == (min_jint / -1)
   541         return TypeInt::make(min_jint, max_jint/2 + 1, widen);
   542       } else {
   543         return TypeInt::make(d, -d, widen);
   544       }
   545     }
   546     return TypeInt::make(-d, d, widen);
   547   }
   549   // Otherwise we give up all hope
   550   return TypeInt::INT;
   551 }
   554 //=============================================================================
   555 //------------------------------Identity---------------------------------------
   556 // If the divisor is 1, we are an identity on the dividend.
   557 Node *DivLNode::Identity( PhaseTransform *phase ) {
   558   return (phase->type( in(2) )->higher_equal(TypeLong::ONE)) ? in(1) : this;
   559 }
   561 //------------------------------Idealize---------------------------------------
   562 // Dividing by a power of 2 is a shift.
   563 Node *DivLNode::Ideal( PhaseGVN *phase, bool can_reshape) {
   564   if (in(0) && remove_dead_region(phase, can_reshape))  return this;
   565   // Don't bother trying to transform a dead node
   566   if( in(0) && in(0)->is_top() )  return NULL;
   568   const Type *t = phase->type( in(2) );
   569   if( t == TypeLong::ONE )      // Identity?
   570     return NULL;                // Skip it
   572   const TypeLong *tl = t->isa_long();
   573   if( !tl ) return NULL;
   574   if( !tl->is_con() ) return NULL;
   575   jlong l = tl->get_con();      // Get divisor
   577   if (l == 0) return NULL;      // Dividing by zero constant does not idealize
   579   set_req(0,NULL);              // Dividing by a not-zero constant; no faulting
   581   // Dividing by MINLONG does not optimize as a power-of-2 shift.
   582   if( l == min_jlong ) return NULL;
   584   return transform_long_divide( phase, in(1), l );
   585 }
   587 //------------------------------Value------------------------------------------
   588 // A DivLNode divides its inputs.  The third input is a Control input, used to
   589 // prevent hoisting the divide above an unsafe test.
   590 const Type *DivLNode::Value( PhaseTransform *phase ) const {
   591   // Either input is TOP ==> the result is TOP
   592   const Type *t1 = phase->type( in(1) );
   593   const Type *t2 = phase->type( in(2) );
   594   if( t1 == Type::TOP ) return Type::TOP;
   595   if( t2 == Type::TOP ) return Type::TOP;
   597   // x/x == 1 since we always generate the dynamic divisor check for 0.
   598   if( phase->eqv( in(1), in(2) ) )
   599     return TypeLong::ONE;
   601   // Either input is BOTTOM ==> the result is the local BOTTOM
   602   const Type *bot = bottom_type();
   603   if( (t1 == bot) || (t2 == bot) ||
   604       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
   605     return bot;
   607   // Divide the two numbers.  We approximate.
   608   // If divisor is a constant and not zero
   609   const TypeLong *i1 = t1->is_long();
   610   const TypeLong *i2 = t2->is_long();
   611   int widen = MAX2(i1->_widen, i2->_widen);
   613   if( i2->is_con() && i2->get_con() != 0 ) {
   614     jlong d = i2->get_con();    // Divisor
   615     jlong lo, hi;
   616     if( d >= 0 ) {
   617       lo = i1->_lo/d;
   618       hi = i1->_hi/d;
   619     } else {
   620       if( d == CONST64(-1) && i1->_lo == min_jlong ) {
   621         // 'min_jlong/-1' throws arithmetic exception during compilation
   622         lo = min_jlong;
   623         // do not support holes, 'hi' must go to either min_jlong or max_jlong:
   624         // [min_jlong, -10]/[-1,-1] ==> [min_jlong] UNION [10,max_jlong]
   625         hi = i1->_hi == min_jlong ? min_jlong : max_jlong;
   626       } else {
   627         lo = i1->_hi/d;
   628         hi = i1->_lo/d;
   629       }
   630     }
   631     return TypeLong::make(lo, hi, widen);
   632   }
   634   // If the dividend is a constant
   635   if( i1->is_con() ) {
   636     jlong d = i1->get_con();
   637     if( d < 0 ) {
   638       if( d == min_jlong ) {
   639         //  (-min_jlong) == min_jlong == (min_jlong / -1)
   640         return TypeLong::make(min_jlong, max_jlong/2 + 1, widen);
   641       } else {
   642         return TypeLong::make(d, -d, widen);
   643       }
   644     }
   645     return TypeLong::make(-d, d, widen);
   646   }
   648   // Otherwise we give up all hope
   649   return TypeLong::LONG;
   650 }
   653 //=============================================================================
   654 //------------------------------Value------------------------------------------
   655 // An DivFNode divides its inputs.  The third input is a Control input, used to
   656 // prevent hoisting the divide above an unsafe test.
   657 const Type *DivFNode::Value( PhaseTransform *phase ) const {
   658   // Either input is TOP ==> the result is TOP
   659   const Type *t1 = phase->type( in(1) );
   660   const Type *t2 = phase->type( in(2) );
   661   if( t1 == Type::TOP ) return Type::TOP;
   662   if( t2 == Type::TOP ) return Type::TOP;
   664   // Either input is BOTTOM ==> the result is the local BOTTOM
   665   const Type *bot = bottom_type();
   666   if( (t1 == bot) || (t2 == bot) ||
   667       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
   668     return bot;
   670   // x/x == 1, we ignore 0/0.
   671   // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
   672   // Does not work for variables because of NaN's
   673   if( phase->eqv( in(1), in(2) ) && t1->base() == Type::FloatCon)
   674     if (!g_isnan(t1->getf()) && g_isfinite(t1->getf()) && t1->getf() != 0.0) // could be negative ZERO or NaN
   675       return TypeF::ONE;
   677   if( t2 == TypeF::ONE )
   678     return t1;
   680   // If divisor is a constant and not zero, divide them numbers
   681   if( t1->base() == Type::FloatCon &&
   682       t2->base() == Type::FloatCon &&
   683       t2->getf() != 0.0 ) // could be negative zero
   684     return TypeF::make( t1->getf()/t2->getf() );
   686   // If the dividend is a constant zero
   687   // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
   688   // Test TypeF::ZERO is not sufficient as it could be negative zero
   690   if( t1 == TypeF::ZERO && !g_isnan(t2->getf()) && t2->getf() != 0.0 )
   691     return TypeF::ZERO;
   693   // Otherwise we give up all hope
   694   return Type::FLOAT;
   695 }
   697 //------------------------------isA_Copy---------------------------------------
   698 // Dividing by self is 1.
   699 // If the divisor is 1, we are an identity on the dividend.
   700 Node *DivFNode::Identity( PhaseTransform *phase ) {
   701   return (phase->type( in(2) ) == TypeF::ONE) ? in(1) : this;
   702 }
   705 //------------------------------Idealize---------------------------------------
   706 Node *DivFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   707   if (in(0) && remove_dead_region(phase, can_reshape))  return this;
   708   // Don't bother trying to transform a dead node
   709   if( in(0) && in(0)->is_top() )  return NULL;
   711   const Type *t2 = phase->type( in(2) );
   712   if( t2 == TypeF::ONE )         // Identity?
   713     return NULL;                // Skip it
   715   const TypeF *tf = t2->isa_float_constant();
   716   if( !tf ) return NULL;
   717   if( tf->base() != Type::FloatCon ) return NULL;
   719   // Check for out of range values
   720   if( tf->is_nan() || !tf->is_finite() ) return NULL;
   722   // Get the value
   723   float f = tf->getf();
   724   int exp;
   726   // Only for special case of dividing by a power of 2
   727   if( frexp((double)f, &exp) != 0.5 ) return NULL;
   729   // Limit the range of acceptable exponents
   730   if( exp < -126 || exp > 126 ) return NULL;
   732   // Compute the reciprocal
   733   float reciprocal = ((float)1.0) / f;
   735   assert( frexp((double)reciprocal, &exp) == 0.5, "reciprocal should be power of 2" );
   737   // return multiplication by the reciprocal
   738   return (new (phase->C) MulFNode(in(1), phase->makecon(TypeF::make(reciprocal))));
   739 }
   741 //=============================================================================
   742 //------------------------------Value------------------------------------------
   743 // An DivDNode divides its inputs.  The third input is a Control input, used to
   744 // prevent hoisting the divide above an unsafe test.
   745 const Type *DivDNode::Value( PhaseTransform *phase ) const {
   746   // Either input is TOP ==> the result is TOP
   747   const Type *t1 = phase->type( in(1) );
   748   const Type *t2 = phase->type( in(2) );
   749   if( t1 == Type::TOP ) return Type::TOP;
   750   if( t2 == Type::TOP ) return Type::TOP;
   752   // Either input is BOTTOM ==> the result is the local BOTTOM
   753   const Type *bot = bottom_type();
   754   if( (t1 == bot) || (t2 == bot) ||
   755       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
   756     return bot;
   758   // x/x == 1, we ignore 0/0.
   759   // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
   760   // Does not work for variables because of NaN's
   761   if( phase->eqv( in(1), in(2) ) && t1->base() == Type::DoubleCon)
   762     if (!g_isnan(t1->getd()) && g_isfinite(t1->getd()) && t1->getd() != 0.0) // could be negative ZERO or NaN
   763       return TypeD::ONE;
   765   if( t2 == TypeD::ONE )
   766     return t1;
   768 #if defined(IA32)
   769   if (!phase->C->method()->is_strict())
   770     // Can't trust native compilers to properly fold strict double
   771     // division with round-to-zero on this platform.
   772 #endif
   773     {
   774       // If divisor is a constant and not zero, divide them numbers
   775       if( t1->base() == Type::DoubleCon &&
   776           t2->base() == Type::DoubleCon &&
   777           t2->getd() != 0.0 ) // could be negative zero
   778         return TypeD::make( t1->getd()/t2->getd() );
   779     }
   781   // If the dividend is a constant zero
   782   // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
   783   // Test TypeF::ZERO is not sufficient as it could be negative zero
   784   if( t1 == TypeD::ZERO && !g_isnan(t2->getd()) && t2->getd() != 0.0 )
   785     return TypeD::ZERO;
   787   // Otherwise we give up all hope
   788   return Type::DOUBLE;
   789 }
   792 //------------------------------isA_Copy---------------------------------------
   793 // Dividing by self is 1.
   794 // If the divisor is 1, we are an identity on the dividend.
   795 Node *DivDNode::Identity( PhaseTransform *phase ) {
   796   return (phase->type( in(2) ) == TypeD::ONE) ? in(1) : this;
   797 }
   799 //------------------------------Idealize---------------------------------------
   800 Node *DivDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   801   if (in(0) && remove_dead_region(phase, can_reshape))  return this;
   802   // Don't bother trying to transform a dead node
   803   if( in(0) && in(0)->is_top() )  return NULL;
   805   const Type *t2 = phase->type( in(2) );
   806   if( t2 == TypeD::ONE )         // Identity?
   807     return NULL;                // Skip it
   809   const TypeD *td = t2->isa_double_constant();
   810   if( !td ) return NULL;
   811   if( td->base() != Type::DoubleCon ) return NULL;
   813   // Check for out of range values
   814   if( td->is_nan() || !td->is_finite() ) return NULL;
   816   // Get the value
   817   double d = td->getd();
   818   int exp;
   820   // Only for special case of dividing by a power of 2
   821   if( frexp(d, &exp) != 0.5 ) return NULL;
   823   // Limit the range of acceptable exponents
   824   if( exp < -1021 || exp > 1022 ) return NULL;
   826   // Compute the reciprocal
   827   double reciprocal = 1.0 / d;
   829   assert( frexp(reciprocal, &exp) == 0.5, "reciprocal should be power of 2" );
   831   // return multiplication by the reciprocal
   832   return (new (phase->C) MulDNode(in(1), phase->makecon(TypeD::make(reciprocal))));
   833 }
   835 //=============================================================================
   836 //------------------------------Idealize---------------------------------------
   837 Node *ModINode::Ideal(PhaseGVN *phase, bool can_reshape) {
   838   // Check for dead control input
   839   if( in(0) && remove_dead_region(phase, can_reshape) )  return this;
   840   // Don't bother trying to transform a dead node
   841   if( in(0) && in(0)->is_top() )  return NULL;
   843   // Get the modulus
   844   const Type *t = phase->type( in(2) );
   845   if( t == Type::TOP ) return NULL;
   846   const TypeInt *ti = t->is_int();
   848   // Check for useless control input
   849   // Check for excluding mod-zero case
   850   if( in(0) && (ti->_hi < 0 || ti->_lo > 0) ) {
   851     set_req(0, NULL);        // Yank control input
   852     return this;
   853   }
   855   // See if we are MOD'ing by 2^k or 2^k-1.
   856   if( !ti->is_con() ) return NULL;
   857   jint con = ti->get_con();
   859   Node *hook = new (phase->C) Node(1);
   861   // First, special check for modulo 2^k-1
   862   if( con >= 0 && con < max_jint && is_power_of_2(con+1) ) {
   863     uint k = exact_log2(con+1);  // Extract k
   865     // Basic algorithm by David Detlefs.  See fastmod_int.java for gory details.
   866     static int unroll_factor[] = { 999, 999, 29, 14, 9, 7, 5, 4, 4, 3, 3, 2, 2, 2, 2, 2, 1 /*past here we assume 1 forever*/};
   867     int trip_count = 1;
   868     if( k < ARRAY_SIZE(unroll_factor))  trip_count = unroll_factor[k];
   870     // If the unroll factor is not too large, and if conditional moves are
   871     // ok, then use this case
   872     if( trip_count <= 5 && ConditionalMoveLimit != 0 ) {
   873       Node *x = in(1);            // Value being mod'd
   874       Node *divisor = in(2);      // Also is mask
   876       hook->init_req(0, x);       // Add a use to x to prevent him from dying
   877       // Generate code to reduce X rapidly to nearly 2^k-1.
   878       for( int i = 0; i < trip_count; i++ ) {
   879         Node *xl = phase->transform( new (phase->C) AndINode(x,divisor) );
   880         Node *xh = phase->transform( new (phase->C) RShiftINode(x,phase->intcon(k)) ); // Must be signed
   881         x = phase->transform( new (phase->C) AddINode(xh,xl) );
   882         hook->set_req(0, x);
   883       }
   885       // Generate sign-fixup code.  Was original value positive?
   886       // int hack_res = (i >= 0) ? divisor : 1;
   887       Node *cmp1 = phase->transform( new (phase->C) CmpINode( in(1), phase->intcon(0) ) );
   888       Node *bol1 = phase->transform( new (phase->C) BoolNode( cmp1, BoolTest::ge ) );
   889       Node *cmov1= phase->transform( new (phase->C) CMoveINode(bol1, phase->intcon(1), divisor, TypeInt::POS) );
   890       // if( x >= hack_res ) x -= divisor;
   891       Node *sub  = phase->transform( new (phase->C) SubINode( x, divisor ) );
   892       Node *cmp2 = phase->transform( new (phase->C) CmpINode( x, cmov1 ) );
   893       Node *bol2 = phase->transform( new (phase->C) BoolNode( cmp2, BoolTest::ge ) );
   894       // Convention is to not transform the return value of an Ideal
   895       // since Ideal is expected to return a modified 'this' or a new node.
   896       Node *cmov2= new (phase->C) CMoveINode(bol2, x, sub, TypeInt::INT);
   897       // cmov2 is now the mod
   899       // Now remove the bogus extra edges used to keep things alive
   900       if (can_reshape) {
   901         phase->is_IterGVN()->remove_dead_node(hook);
   902       } else {
   903         hook->set_req(0, NULL);   // Just yank bogus edge during Parse phase
   904       }
   905       return cmov2;
   906     }
   907   }
   909   // Fell thru, the unroll case is not appropriate. Transform the modulo
   910   // into a long multiply/int multiply/subtract case
   912   // Cannot handle mod 0, and min_jint isn't handled by the transform
   913   if( con == 0 || con == min_jint ) return NULL;
   915   // Get the absolute value of the constant; at this point, we can use this
   916   jint pos_con = (con >= 0) ? con : -con;
   918   // integer Mod 1 is always 0
   919   if( pos_con == 1 ) return new (phase->C) ConINode(TypeInt::ZERO);
   921   int log2_con = -1;
   923   // If this is a power of two, they maybe we can mask it
   924   if( is_power_of_2(pos_con) ) {
   925     log2_con = log2_intptr((intptr_t)pos_con);
   927     const Type *dt = phase->type(in(1));
   928     const TypeInt *dti = dt->isa_int();
   930     // See if this can be masked, if the dividend is non-negative
   931     if( dti && dti->_lo >= 0 )
   932       return ( new (phase->C) AndINode( in(1), phase->intcon( pos_con-1 ) ) );
   933   }
   935   // Save in(1) so that it cannot be changed or deleted
   936   hook->init_req(0, in(1));
   938   // Divide using the transform from DivI to MulL
   939   Node *result = transform_int_divide( phase, in(1), pos_con );
   940   if (result != NULL) {
   941     Node *divide = phase->transform(result);
   943     // Re-multiply, using a shift if this is a power of two
   944     Node *mult = NULL;
   946     if( log2_con >= 0 )
   947       mult = phase->transform( new (phase->C) LShiftINode( divide, phase->intcon( log2_con ) ) );
   948     else
   949       mult = phase->transform( new (phase->C) MulINode( divide, phase->intcon( pos_con ) ) );
   951     // Finally, subtract the multiplied divided value from the original
   952     result = new (phase->C) SubINode( in(1), mult );
   953   }
   955   // Now remove the bogus extra edges used to keep things alive
   956   if (can_reshape) {
   957     phase->is_IterGVN()->remove_dead_node(hook);
   958   } else {
   959     hook->set_req(0, NULL);       // Just yank bogus edge during Parse phase
   960   }
   962   // return the value
   963   return result;
   964 }
   966 //------------------------------Value------------------------------------------
   967 const Type *ModINode::Value( PhaseTransform *phase ) const {
   968   // Either input is TOP ==> the result is TOP
   969   const Type *t1 = phase->type( in(1) );
   970   const Type *t2 = phase->type( in(2) );
   971   if( t1 == Type::TOP ) return Type::TOP;
   972   if( t2 == Type::TOP ) return Type::TOP;
   974   // We always generate the dynamic check for 0.
   975   // 0 MOD X is 0
   976   if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
   977   // X MOD X is 0
   978   if( phase->eqv( in(1), in(2) ) ) return TypeInt::ZERO;
   980   // Either input is BOTTOM ==> the result is the local BOTTOM
   981   const Type *bot = bottom_type();
   982   if( (t1 == bot) || (t2 == bot) ||
   983       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
   984     return bot;
   986   const TypeInt *i1 = t1->is_int();
   987   const TypeInt *i2 = t2->is_int();
   988   if( !i1->is_con() || !i2->is_con() ) {
   989     if( i1->_lo >= 0 && i2->_lo >= 0 )
   990       return TypeInt::POS;
   991     // If both numbers are not constants, we know little.
   992     return TypeInt::INT;
   993   }
   994   // Mod by zero?  Throw exception at runtime!
   995   if( !i2->get_con() ) return TypeInt::POS;
   997   // We must be modulo'ing 2 float constants.
   998   // Check for min_jint % '-1', result is defined to be '0'.
   999   if( i1->get_con() == min_jint && i2->get_con() == -1 )
  1000     return TypeInt::ZERO;
  1002   return TypeInt::make( i1->get_con() % i2->get_con() );
  1006 //=============================================================================
  1007 //------------------------------Idealize---------------------------------------
  1008 Node *ModLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
  1009   // Check for dead control input
  1010   if( in(0) && remove_dead_region(phase, can_reshape) )  return this;
  1011   // Don't bother trying to transform a dead node
  1012   if( in(0) && in(0)->is_top() )  return NULL;
  1014   // Get the modulus
  1015   const Type *t = phase->type( in(2) );
  1016   if( t == Type::TOP ) return NULL;
  1017   const TypeLong *tl = t->is_long();
  1019   // Check for useless control input
  1020   // Check for excluding mod-zero case
  1021   if( in(0) && (tl->_hi < 0 || tl->_lo > 0) ) {
  1022     set_req(0, NULL);        // Yank control input
  1023     return this;
  1026   // See if we are MOD'ing by 2^k or 2^k-1.
  1027   if( !tl->is_con() ) return NULL;
  1028   jlong con = tl->get_con();
  1030   Node *hook = new (phase->C) Node(1);
  1032   // Expand mod
  1033   if( con >= 0 && con < max_jlong && is_power_of_2_long(con+1) ) {
  1034     uint k = exact_log2_long(con+1);  // Extract k
  1036     // Basic algorithm by David Detlefs.  See fastmod_long.java for gory details.
  1037     // Used to help a popular random number generator which does a long-mod
  1038     // of 2^31-1 and shows up in SpecJBB and SciMark.
  1039     static int unroll_factor[] = { 999, 999, 61, 30, 20, 15, 12, 10, 8, 7, 6, 6, 5, 5, 4, 4, 4, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1 /*past here we assume 1 forever*/};
  1040     int trip_count = 1;
  1041     if( k < ARRAY_SIZE(unroll_factor)) trip_count = unroll_factor[k];
  1043     // If the unroll factor is not too large, and if conditional moves are
  1044     // ok, then use this case
  1045     if( trip_count <= 5 && ConditionalMoveLimit != 0 ) {
  1046       Node *x = in(1);            // Value being mod'd
  1047       Node *divisor = in(2);      // Also is mask
  1049       hook->init_req(0, x);       // Add a use to x to prevent him from dying
  1050       // Generate code to reduce X rapidly to nearly 2^k-1.
  1051       for( int i = 0; i < trip_count; i++ ) {
  1052         Node *xl = phase->transform( new (phase->C) AndLNode(x,divisor) );
  1053         Node *xh = phase->transform( new (phase->C) RShiftLNode(x,phase->intcon(k)) ); // Must be signed
  1054         x = phase->transform( new (phase->C) AddLNode(xh,xl) );
  1055         hook->set_req(0, x);    // Add a use to x to prevent him from dying
  1058       // Generate sign-fixup code.  Was original value positive?
  1059       // long hack_res = (i >= 0) ? divisor : CONST64(1);
  1060       Node *cmp1 = phase->transform( new (phase->C) CmpLNode( in(1), phase->longcon(0) ) );
  1061       Node *bol1 = phase->transform( new (phase->C) BoolNode( cmp1, BoolTest::ge ) );
  1062       Node *cmov1= phase->transform( new (phase->C) CMoveLNode(bol1, phase->longcon(1), divisor, TypeLong::LONG) );
  1063       // if( x >= hack_res ) x -= divisor;
  1064       Node *sub  = phase->transform( new (phase->C) SubLNode( x, divisor ) );
  1065       Node *cmp2 = phase->transform( new (phase->C) CmpLNode( x, cmov1 ) );
  1066       Node *bol2 = phase->transform( new (phase->C) BoolNode( cmp2, BoolTest::ge ) );
  1067       // Convention is to not transform the return value of an Ideal
  1068       // since Ideal is expected to return a modified 'this' or a new node.
  1069       Node *cmov2= new (phase->C) CMoveLNode(bol2, x, sub, TypeLong::LONG);
  1070       // cmov2 is now the mod
  1072       // Now remove the bogus extra edges used to keep things alive
  1073       if (can_reshape) {
  1074         phase->is_IterGVN()->remove_dead_node(hook);
  1075       } else {
  1076         hook->set_req(0, NULL);   // Just yank bogus edge during Parse phase
  1078       return cmov2;
  1082   // Fell thru, the unroll case is not appropriate. Transform the modulo
  1083   // into a long multiply/int multiply/subtract case
  1085   // Cannot handle mod 0, and min_jlong isn't handled by the transform
  1086   if( con == 0 || con == min_jlong ) return NULL;
  1088   // Get the absolute value of the constant; at this point, we can use this
  1089   jlong pos_con = (con >= 0) ? con : -con;
  1091   // integer Mod 1 is always 0
  1092   if( pos_con == 1 ) return new (phase->C) ConLNode(TypeLong::ZERO);
  1094   int log2_con = -1;
  1096   // If this is a power of two, then maybe we can mask it
  1097   if( is_power_of_2_long(pos_con) ) {
  1098     log2_con = exact_log2_long(pos_con);
  1100     const Type *dt = phase->type(in(1));
  1101     const TypeLong *dtl = dt->isa_long();
  1103     // See if this can be masked, if the dividend is non-negative
  1104     if( dtl && dtl->_lo >= 0 )
  1105       return ( new (phase->C) AndLNode( in(1), phase->longcon( pos_con-1 ) ) );
  1108   // Save in(1) so that it cannot be changed or deleted
  1109   hook->init_req(0, in(1));
  1111   // Divide using the transform from DivL to MulL
  1112   Node *result = transform_long_divide( phase, in(1), pos_con );
  1113   if (result != NULL) {
  1114     Node *divide = phase->transform(result);
  1116     // Re-multiply, using a shift if this is a power of two
  1117     Node *mult = NULL;
  1119     if( log2_con >= 0 )
  1120       mult = phase->transform( new (phase->C) LShiftLNode( divide, phase->intcon( log2_con ) ) );
  1121     else
  1122       mult = phase->transform( new (phase->C) MulLNode( divide, phase->longcon( pos_con ) ) );
  1124     // Finally, subtract the multiplied divided value from the original
  1125     result = new (phase->C) SubLNode( in(1), mult );
  1128   // Now remove the bogus extra edges used to keep things alive
  1129   if (can_reshape) {
  1130     phase->is_IterGVN()->remove_dead_node(hook);
  1131   } else {
  1132     hook->set_req(0, NULL);       // Just yank bogus edge during Parse phase
  1135   // return the value
  1136   return result;
  1139 //------------------------------Value------------------------------------------
  1140 const Type *ModLNode::Value( PhaseTransform *phase ) const {
  1141   // Either input is TOP ==> the result is TOP
  1142   const Type *t1 = phase->type( in(1) );
  1143   const Type *t2 = phase->type( in(2) );
  1144   if( t1 == Type::TOP ) return Type::TOP;
  1145   if( t2 == Type::TOP ) return Type::TOP;
  1147   // We always generate the dynamic check for 0.
  1148   // 0 MOD X is 0
  1149   if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
  1150   // X MOD X is 0
  1151   if( phase->eqv( in(1), in(2) ) ) return TypeLong::ZERO;
  1153   // Either input is BOTTOM ==> the result is the local BOTTOM
  1154   const Type *bot = bottom_type();
  1155   if( (t1 == bot) || (t2 == bot) ||
  1156       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
  1157     return bot;
  1159   const TypeLong *i1 = t1->is_long();
  1160   const TypeLong *i2 = t2->is_long();
  1161   if( !i1->is_con() || !i2->is_con() ) {
  1162     if( i1->_lo >= CONST64(0) && i2->_lo >= CONST64(0) )
  1163       return TypeLong::POS;
  1164     // If both numbers are not constants, we know little.
  1165     return TypeLong::LONG;
  1167   // Mod by zero?  Throw exception at runtime!
  1168   if( !i2->get_con() ) return TypeLong::POS;
  1170   // We must be modulo'ing 2 float constants.
  1171   // Check for min_jint % '-1', result is defined to be '0'.
  1172   if( i1->get_con() == min_jlong && i2->get_con() == -1 )
  1173     return TypeLong::ZERO;
  1175   return TypeLong::make( i1->get_con() % i2->get_con() );
  1179 //=============================================================================
  1180 //------------------------------Value------------------------------------------
  1181 const Type *ModFNode::Value( PhaseTransform *phase ) const {
  1182   // Either input is TOP ==> the result is TOP
  1183   const Type *t1 = phase->type( in(1) );
  1184   const Type *t2 = phase->type( in(2) );
  1185   if( t1 == Type::TOP ) return Type::TOP;
  1186   if( t2 == Type::TOP ) return Type::TOP;
  1188   // Either input is BOTTOM ==> the result is the local BOTTOM
  1189   const Type *bot = bottom_type();
  1190   if( (t1 == bot) || (t2 == bot) ||
  1191       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
  1192     return bot;
  1194   // If either number is not a constant, we know nothing.
  1195   if ((t1->base() != Type::FloatCon) || (t2->base() != Type::FloatCon)) {
  1196     return Type::FLOAT;         // note: x%x can be either NaN or 0
  1199   float f1 = t1->getf();
  1200   float f2 = t2->getf();
  1201   jint  x1 = jint_cast(f1);     // note:  *(int*)&f1, not just (int)f1
  1202   jint  x2 = jint_cast(f2);
  1204   // If either is a NaN, return an input NaN
  1205   if (g_isnan(f1))    return t1;
  1206   if (g_isnan(f2))    return t2;
  1208   // If an operand is infinity or the divisor is +/- zero, punt.
  1209   if (!g_isfinite(f1) || !g_isfinite(f2) || x2 == 0 || x2 == min_jint)
  1210     return Type::FLOAT;
  1212   // We must be modulo'ing 2 float constants.
  1213   // Make sure that the sign of the fmod is equal to the sign of the dividend
  1214   jint xr = jint_cast(fmod(f1, f2));
  1215   if ((x1 ^ xr) < 0) {
  1216     xr ^= min_jint;
  1219   return TypeF::make(jfloat_cast(xr));
  1223 //=============================================================================
  1224 //------------------------------Value------------------------------------------
  1225 const Type *ModDNode::Value( PhaseTransform *phase ) const {
  1226   // Either input is TOP ==> the result is TOP
  1227   const Type *t1 = phase->type( in(1) );
  1228   const Type *t2 = phase->type( in(2) );
  1229   if( t1 == Type::TOP ) return Type::TOP;
  1230   if( t2 == Type::TOP ) return Type::TOP;
  1232   // Either input is BOTTOM ==> the result is the local BOTTOM
  1233   const Type *bot = bottom_type();
  1234   if( (t1 == bot) || (t2 == bot) ||
  1235       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
  1236     return bot;
  1238   // If either number is not a constant, we know nothing.
  1239   if ((t1->base() != Type::DoubleCon) || (t2->base() != Type::DoubleCon)) {
  1240     return Type::DOUBLE;        // note: x%x can be either NaN or 0
  1243   double f1 = t1->getd();
  1244   double f2 = t2->getd();
  1245   jlong  x1 = jlong_cast(f1);   // note:  *(long*)&f1, not just (long)f1
  1246   jlong  x2 = jlong_cast(f2);
  1248   // If either is a NaN, return an input NaN
  1249   if (g_isnan(f1))    return t1;
  1250   if (g_isnan(f2))    return t2;
  1252   // If an operand is infinity or the divisor is +/- zero, punt.
  1253   if (!g_isfinite(f1) || !g_isfinite(f2) || x2 == 0 || x2 == min_jlong)
  1254     return Type::DOUBLE;
  1256   // We must be modulo'ing 2 double constants.
  1257   // Make sure that the sign of the fmod is equal to the sign of the dividend
  1258   jlong xr = jlong_cast(fmod(f1, f2));
  1259   if ((x1 ^ xr) < 0) {
  1260     xr ^= min_jlong;
  1263   return TypeD::make(jdouble_cast(xr));
  1266 //=============================================================================
  1268 DivModNode::DivModNode( Node *c, Node *dividend, Node *divisor ) : MultiNode(3) {
  1269   init_req(0, c);
  1270   init_req(1, dividend);
  1271   init_req(2, divisor);
  1274 //------------------------------make------------------------------------------
  1275 DivModINode* DivModINode::make(Compile* C, Node* div_or_mod) {
  1276   Node* n = div_or_mod;
  1277   assert(n->Opcode() == Op_DivI || n->Opcode() == Op_ModI,
  1278          "only div or mod input pattern accepted");
  1280   DivModINode* divmod = new (C) DivModINode(n->in(0), n->in(1), n->in(2));
  1281   Node*        dproj  = new (C) ProjNode(divmod, DivModNode::div_proj_num);
  1282   Node*        mproj  = new (C) ProjNode(divmod, DivModNode::mod_proj_num);
  1283   return divmod;
  1286 //------------------------------make------------------------------------------
  1287 DivModLNode* DivModLNode::make(Compile* C, Node* div_or_mod) {
  1288   Node* n = div_or_mod;
  1289   assert(n->Opcode() == Op_DivL || n->Opcode() == Op_ModL,
  1290          "only div or mod input pattern accepted");
  1292   DivModLNode* divmod = new (C) DivModLNode(n->in(0), n->in(1), n->in(2));
  1293   Node*        dproj  = new (C) ProjNode(divmod, DivModNode::div_proj_num);
  1294   Node*        mproj  = new (C) ProjNode(divmod, DivModNode::mod_proj_num);
  1295   return divmod;
  1298 //------------------------------match------------------------------------------
  1299 // return result(s) along with their RegMask info
  1300 Node *DivModINode::match( const ProjNode *proj, const Matcher *match ) {
  1301   uint ideal_reg = proj->ideal_reg();
  1302   RegMask rm;
  1303   if (proj->_con == div_proj_num) {
  1304     rm = match->divI_proj_mask();
  1305   } else {
  1306     assert(proj->_con == mod_proj_num, "must be div or mod projection");
  1307     rm = match->modI_proj_mask();
  1309   return new (match->C)MachProjNode(this, proj->_con, rm, ideal_reg);
  1313 //------------------------------match------------------------------------------
  1314 // return result(s) along with their RegMask info
  1315 Node *DivModLNode::match( const ProjNode *proj, const Matcher *match ) {
  1316   uint ideal_reg = proj->ideal_reg();
  1317   RegMask rm;
  1318   if (proj->_con == div_proj_num) {
  1319     rm = match->divL_proj_mask();
  1320   } else {
  1321     assert(proj->_con == mod_proj_num, "must be div or mod projection");
  1322     rm = match->modL_proj_mask();
  1324   return new (match->C)MachProjNode(this, proj->_con, rm, ideal_reg);

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