src/share/vm/opto/divnode.cpp

Wed, 06 May 2009 12:04:42 -0700

author
twisti
date
Wed, 06 May 2009 12:04:42 -0700
changeset 1191
cecd04fc6f93
parent 1040
98cb887364d3
child 1589
174ade00803b
permissions
-rw-r--r--

6837011: SIGSEGV in PhaseIdealLoop in 32bit jvm
Summary: The CR's test crashes with SIGSEGV when running with "-server -Xcomp" using using 32bit jvm.
Reviewed-by: kvn, never, rasbold

     1 /*
     2  * Copyright 1997-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 // Portions of code courtesy of Clifford Click
    27 // Optimization - Graph Style
    29 #include "incls/_precompiled.incl"
    30 #include "incls/_divnode.cpp.incl"
    31 #include <math.h>
    33 //----------------------magic_int_divide_constants-----------------------------
    34 // Compute magic multiplier and shift constant for converting a 32 bit divide
    35 // by constant into a multiply/shift/add series. Return false if calculations
    36 // fail.
    37 //
    38 // Borrowed almost verbatim from Hacker's Delight by Henry S. Warren, Jr. with
    39 // minor type name and parameter changes.
    40 static bool magic_int_divide_constants(jint d, jint &M, jint &s) {
    41   int32_t p;
    42   uint32_t ad, anc, delta, q1, r1, q2, r2, t;
    43   const uint32_t two31 = 0x80000000L;     // 2**31.
    45   ad = ABS(d);
    46   if (d == 0 || d == 1) return false;
    47   t = two31 + ((uint32_t)d >> 31);
    48   anc = t - 1 - t%ad;     // Absolute value of nc.
    49   p = 31;                 // Init. p.
    50   q1 = two31/anc;         // Init. q1 = 2**p/|nc|.
    51   r1 = two31 - q1*anc;    // Init. r1 = rem(2**p, |nc|).
    52   q2 = two31/ad;          // Init. q2 = 2**p/|d|.
    53   r2 = two31 - q2*ad;     // Init. r2 = rem(2**p, |d|).
    54   do {
    55     p = p + 1;
    56     q1 = 2*q1;            // Update q1 = 2**p/|nc|.
    57     r1 = 2*r1;            // Update r1 = rem(2**p, |nc|).
    58     if (r1 >= anc) {      // (Must be an unsigned
    59       q1 = q1 + 1;        // comparison here).
    60       r1 = r1 - anc;
    61     }
    62     q2 = 2*q2;            // Update q2 = 2**p/|d|.
    63     r2 = 2*r2;            // Update r2 = rem(2**p, |d|).
    64     if (r2 >= ad) {       // (Must be an unsigned
    65       q2 = q2 + 1;        // comparison here).
    66       r2 = r2 - ad;
    67     }
    68     delta = ad - r2;
    69   } while (q1 < delta || (q1 == delta && r1 == 0));
    71   M = q2 + 1;
    72   if (d < 0) M = -M;      // Magic number and
    73   s = p - 32;             // shift amount to return.
    75   return true;
    76 }
    78 //--------------------------transform_int_divide-------------------------------
    79 // Convert a division by constant divisor into an alternate Ideal graph.
    80 // Return NULL if no transformation occurs.
    81 static Node *transform_int_divide( PhaseGVN *phase, Node *dividend, jint divisor ) {
    83   // Check for invalid divisors
    84   assert( divisor != 0 && divisor != min_jint,
    85           "bad divisor for transforming to long multiply" );
    87   bool d_pos = divisor >= 0;
    88   jint d = d_pos ? divisor : -divisor;
    89   const int N = 32;
    91   // Result
    92   Node *q = NULL;
    94   if (d == 1) {
    95     // division by +/- 1
    96     if (!d_pos) {
    97       // Just negate the value
    98       q = new (phase->C, 3) SubINode(phase->intcon(0), dividend);
    99     }
   100   } else if ( is_power_of_2(d) ) {
   101     // division by +/- a power of 2
   103     // See if we can simply do a shift without rounding
   104     bool needs_rounding = true;
   105     const Type *dt = phase->type(dividend);
   106     const TypeInt *dti = dt->isa_int();
   107     if (dti && dti->_lo >= 0) {
   108       // we don't need to round a positive dividend
   109       needs_rounding = false;
   110     } else if( dividend->Opcode() == Op_AndI ) {
   111       // An AND mask of sufficient size clears the low bits and
   112       // I can avoid rounding.
   113       const TypeInt *andconi_t = phase->type( dividend->in(2) )->isa_int();
   114       if( andconi_t && andconi_t->is_con() ) {
   115         jint andconi = andconi_t->get_con();
   116         if( andconi < 0 && is_power_of_2(-andconi) && (-andconi) >= d ) {
   117           dividend = dividend->in(1);
   118           needs_rounding = false;
   119         }
   120       }
   121     }
   123     // Add rounding to the shift to handle the sign bit
   124     int l = log2_intptr(d-1)+1;
   125     if (needs_rounding) {
   126       // Divide-by-power-of-2 can be made into a shift, but you have to do
   127       // more math for the rounding.  You need to add 0 for positive
   128       // numbers, and "i-1" for negative numbers.  Example: i=4, so the
   129       // shift is by 2.  You need to add 3 to negative dividends and 0 to
   130       // positive ones.  So (-7+3)>>2 becomes -1, (-4+3)>>2 becomes -1,
   131       // (-2+3)>>2 becomes 0, etc.
   133       // Compute 0 or -1, based on sign bit
   134       Node *sign = phase->transform(new (phase->C, 3) RShiftINode(dividend, phase->intcon(N - 1)));
   135       // Mask sign bit to the low sign bits
   136       Node *round = phase->transform(new (phase->C, 3) URShiftINode(sign, phase->intcon(N - l)));
   137       // Round up before shifting
   138       dividend = phase->transform(new (phase->C, 3) AddINode(dividend, round));
   139     }
   141     // Shift for division
   142     q = new (phase->C, 3) RShiftINode(dividend, phase->intcon(l));
   144     if (!d_pos) {
   145       q = new (phase->C, 3) SubINode(phase->intcon(0), phase->transform(q));
   146     }
   147   } else {
   148     // Attempt the jint constant divide -> multiply transform found in
   149     //   "Division by Invariant Integers using Multiplication"
   150     //     by Granlund and Montgomery
   151     // See also "Hacker's Delight", chapter 10 by Warren.
   153     jint magic_const;
   154     jint shift_const;
   155     if (magic_int_divide_constants(d, magic_const, shift_const)) {
   156       Node *magic = phase->longcon(magic_const);
   157       Node *dividend_long = phase->transform(new (phase->C, 2) ConvI2LNode(dividend));
   159       // Compute the high half of the dividend x magic multiplication
   160       Node *mul_hi = phase->transform(new (phase->C, 3) MulLNode(dividend_long, magic));
   162       if (magic_const < 0) {
   163         mul_hi = phase->transform(new (phase->C, 3) RShiftLNode(mul_hi, phase->intcon(N)));
   164         mul_hi = phase->transform(new (phase->C, 2) ConvL2INode(mul_hi));
   166         // The magic multiplier is too large for a 32 bit constant. We've adjusted
   167         // it down by 2^32, but have to add 1 dividend back in after the multiplication.
   168         // This handles the "overflow" case described by Granlund and Montgomery.
   169         mul_hi = phase->transform(new (phase->C, 3) AddINode(dividend, mul_hi));
   171         // Shift over the (adjusted) mulhi
   172         if (shift_const != 0) {
   173           mul_hi = phase->transform(new (phase->C, 3) RShiftINode(mul_hi, phase->intcon(shift_const)));
   174         }
   175       } else {
   176         // No add is required, we can merge the shifts together.
   177         mul_hi = phase->transform(new (phase->C, 3) RShiftLNode(mul_hi, phase->intcon(N + shift_const)));
   178         mul_hi = phase->transform(new (phase->C, 2) ConvL2INode(mul_hi));
   179       }
   181       // Get a 0 or -1 from the sign of the dividend.
   182       Node *addend0 = mul_hi;
   183       Node *addend1 = phase->transform(new (phase->C, 3) RShiftINode(dividend, phase->intcon(N-1)));
   185       // If the divisor is negative, swap the order of the input addends;
   186       // this has the effect of negating the quotient.
   187       if (!d_pos) {
   188         Node *temp = addend0; addend0 = addend1; addend1 = temp;
   189       }
   191       // Adjust the final quotient by subtracting -1 (adding 1)
   192       // from the mul_hi.
   193       q = new (phase->C, 3) SubINode(addend0, addend1);
   194     }
   195   }
   197   return q;
   198 }
   200 //---------------------magic_long_divide_constants-----------------------------
   201 // Compute magic multiplier and shift constant for converting a 64 bit divide
   202 // by constant into a multiply/shift/add series. Return false if calculations
   203 // fail.
   204 //
   205 // Borrowed almost verbatim from Hacker's Delight by Henry S. Warren, Jr. with
   206 // minor type name and parameter changes.  Adjusted to 64 bit word width.
   207 static bool magic_long_divide_constants(jlong d, jlong &M, jint &s) {
   208   int64_t p;
   209   uint64_t ad, anc, delta, q1, r1, q2, r2, t;
   210   const uint64_t two63 = 0x8000000000000000LL;     // 2**63.
   212   ad = ABS(d);
   213   if (d == 0 || d == 1) return false;
   214   t = two63 + ((uint64_t)d >> 63);
   215   anc = t - 1 - t%ad;     // Absolute value of nc.
   216   p = 63;                 // Init. p.
   217   q1 = two63/anc;         // Init. q1 = 2**p/|nc|.
   218   r1 = two63 - q1*anc;    // Init. r1 = rem(2**p, |nc|).
   219   q2 = two63/ad;          // Init. q2 = 2**p/|d|.
   220   r2 = two63 - q2*ad;     // Init. r2 = rem(2**p, |d|).
   221   do {
   222     p = p + 1;
   223     q1 = 2*q1;            // Update q1 = 2**p/|nc|.
   224     r1 = 2*r1;            // Update r1 = rem(2**p, |nc|).
   225     if (r1 >= anc) {      // (Must be an unsigned
   226       q1 = q1 + 1;        // comparison here).
   227       r1 = r1 - anc;
   228     }
   229     q2 = 2*q2;            // Update q2 = 2**p/|d|.
   230     r2 = 2*r2;            // Update r2 = rem(2**p, |d|).
   231     if (r2 >= ad) {       // (Must be an unsigned
   232       q2 = q2 + 1;        // comparison here).
   233       r2 = r2 - ad;
   234     }
   235     delta = ad - r2;
   236   } while (q1 < delta || (q1 == delta && r1 == 0));
   238   M = q2 + 1;
   239   if (d < 0) M = -M;      // Magic number and
   240   s = p - 64;             // shift amount to return.
   242   return true;
   243 }
   245 //---------------------long_by_long_mulhi--------------------------------------
   246 // Generate ideal node graph for upper half of a 64 bit x 64 bit multiplication
   247 static Node* long_by_long_mulhi(PhaseGVN* phase, Node* dividend, jlong magic_const) {
   248   // If the architecture supports a 64x64 mulhi, there is
   249   // no need to synthesize it in ideal nodes.
   250   if (Matcher::has_match_rule(Op_MulHiL)) {
   251     Node* v = phase->longcon(magic_const);
   252     return new (phase->C, 3) MulHiLNode(dividend, v);
   253   }
   255   // Taken from Hacker's Delight, Fig. 8-2. Multiply high signed.
   256   // (http://www.hackersdelight.org/HDcode/mulhs.c)
   257   //
   258   // int mulhs(int u, int v) {
   259   //    unsigned u0, v0, w0;
   260   //    int u1, v1, w1, w2, t;
   261   //
   262   //    u0 = u & 0xFFFF;  u1 = u >> 16;
   263   //    v0 = v & 0xFFFF;  v1 = v >> 16;
   264   //    w0 = u0*v0;
   265   //    t  = u1*v0 + (w0 >> 16);
   266   //    w1 = t & 0xFFFF;
   267   //    w2 = t >> 16;
   268   //    w1 = u0*v1 + w1;
   269   //    return u1*v1 + w2 + (w1 >> 16);
   270   // }
   271   //
   272   // Note: The version above is for 32x32 multiplications, while the
   273   // following inline comments are adapted to 64x64.
   275   const int N = 64;
   277   // u0 = u & 0xFFFFFFFF;  u1 = u >> 32;
   278   Node* u0 = phase->transform(new (phase->C, 3) AndLNode(dividend, phase->longcon(0xFFFFFFFF)));
   279   Node* u1 = phase->transform(new (phase->C, 3) RShiftLNode(dividend, phase->intcon(N / 2)));
   281   // v0 = v & 0xFFFFFFFF;  v1 = v >> 32;
   282   Node* v0 = phase->longcon(magic_const & 0xFFFFFFFF);
   283   Node* v1 = phase->longcon(magic_const >> (N / 2));
   285   // w0 = u0*v0;
   286   Node* w0 = phase->transform(new (phase->C, 3) MulLNode(u0, v0));
   288   // t = u1*v0 + (w0 >> 32);
   289   Node* u1v0 = phase->transform(new (phase->C, 3) MulLNode(u1, v0));
   290   Node* temp = phase->transform(new (phase->C, 3) URShiftLNode(w0, phase->intcon(N / 2)));
   291   Node* t    = phase->transform(new (phase->C, 3) AddLNode(u1v0, temp));
   293   // w1 = t & 0xFFFFFFFF;
   294   Node* w1 = new (phase->C, 3) AndLNode(t, phase->longcon(0xFFFFFFFF));
   296   // w2 = t >> 32;
   297   Node* w2 = new (phase->C, 3) RShiftLNode(t, phase->intcon(N / 2));
   299   // 6732154: Construct both w1 and w2 before transforming, so t
   300   // doesn't go dead prematurely.
   301   // 6837011: We need to transform w2 before w1 because the
   302   // transformation of w1 could return t.
   303   w2 = phase->transform(w2);
   304   w1 = phase->transform(w1);
   306   // w1 = u0*v1 + w1;
   307   Node* u0v1 = phase->transform(new (phase->C, 3) MulLNode(u0, v1));
   308   w1         = phase->transform(new (phase->C, 3) AddLNode(u0v1, w1));
   310   // return u1*v1 + w2 + (w1 >> 32);
   311   Node* u1v1  = phase->transform(new (phase->C, 3) MulLNode(u1, v1));
   312   Node* temp1 = phase->transform(new (phase->C, 3) AddLNode(u1v1, w2));
   313   Node* temp2 = phase->transform(new (phase->C, 3) RShiftLNode(w1, phase->intcon(N / 2)));
   315   return new (phase->C, 3) AddLNode(temp1, temp2);
   316 }
   319 //--------------------------transform_long_divide------------------------------
   320 // Convert a division by constant divisor into an alternate Ideal graph.
   321 // Return NULL if no transformation occurs.
   322 static Node *transform_long_divide( PhaseGVN *phase, Node *dividend, jlong divisor ) {
   323   // Check for invalid divisors
   324   assert( divisor != 0L && divisor != min_jlong,
   325           "bad divisor for transforming to long multiply" );
   327   bool d_pos = divisor >= 0;
   328   jlong d = d_pos ? divisor : -divisor;
   329   const int N = 64;
   331   // Result
   332   Node *q = NULL;
   334   if (d == 1) {
   335     // division by +/- 1
   336     if (!d_pos) {
   337       // Just negate the value
   338       q = new (phase->C, 3) SubLNode(phase->longcon(0), dividend);
   339     }
   340   } else if ( is_power_of_2_long(d) ) {
   342     // division by +/- a power of 2
   344     // See if we can simply do a shift without rounding
   345     bool needs_rounding = true;
   346     const Type *dt = phase->type(dividend);
   347     const TypeLong *dtl = dt->isa_long();
   349     if (dtl && dtl->_lo > 0) {
   350       // we don't need to round a positive dividend
   351       needs_rounding = false;
   352     } else if( dividend->Opcode() == Op_AndL ) {
   353       // An AND mask of sufficient size clears the low bits and
   354       // I can avoid rounding.
   355       const TypeLong *andconl_t = phase->type( dividend->in(2) )->isa_long();
   356       if( andconl_t && andconl_t->is_con() ) {
   357         jlong andconl = andconl_t->get_con();
   358         if( andconl < 0 && is_power_of_2_long(-andconl) && (-andconl) >= d ) {
   359           dividend = dividend->in(1);
   360           needs_rounding = false;
   361         }
   362       }
   363     }
   365     // Add rounding to the shift to handle the sign bit
   366     int l = log2_long(d-1)+1;
   367     if (needs_rounding) {
   368       // Divide-by-power-of-2 can be made into a shift, but you have to do
   369       // more math for the rounding.  You need to add 0 for positive
   370       // numbers, and "i-1" for negative numbers.  Example: i=4, so the
   371       // shift is by 2.  You need to add 3 to negative dividends and 0 to
   372       // positive ones.  So (-7+3)>>2 becomes -1, (-4+3)>>2 becomes -1,
   373       // (-2+3)>>2 becomes 0, etc.
   375       // Compute 0 or -1, based on sign bit
   376       Node *sign = phase->transform(new (phase->C, 3) RShiftLNode(dividend, phase->intcon(N - 1)));
   377       // Mask sign bit to the low sign bits
   378       Node *round = phase->transform(new (phase->C, 3) URShiftLNode(sign, phase->intcon(N - l)));
   379       // Round up before shifting
   380       dividend = phase->transform(new (phase->C, 3) AddLNode(dividend, round));
   381     }
   383     // Shift for division
   384     q = new (phase->C, 3) RShiftLNode(dividend, phase->intcon(l));
   386     if (!d_pos) {
   387       q = new (phase->C, 3) SubLNode(phase->longcon(0), phase->transform(q));
   388     }
   389   } else {
   390     // Attempt the jlong constant divide -> multiply transform found in
   391     //   "Division by Invariant Integers using Multiplication"
   392     //     by Granlund and Montgomery
   393     // See also "Hacker's Delight", chapter 10 by Warren.
   395     jlong magic_const;
   396     jint shift_const;
   397     if (magic_long_divide_constants(d, magic_const, shift_const)) {
   398       // Compute the high half of the dividend x magic multiplication
   399       Node *mul_hi = phase->transform(long_by_long_mulhi(phase, dividend, magic_const));
   401       // The high half of the 128-bit multiply is computed.
   402       if (magic_const < 0) {
   403         // The magic multiplier is too large for a 64 bit constant. We've adjusted
   404         // it down by 2^64, but have to add 1 dividend back in after the multiplication.
   405         // This handles the "overflow" case described by Granlund and Montgomery.
   406         mul_hi = phase->transform(new (phase->C, 3) AddLNode(dividend, mul_hi));
   407       }
   409       // Shift over the (adjusted) mulhi
   410       if (shift_const != 0) {
   411         mul_hi = phase->transform(new (phase->C, 3) RShiftLNode(mul_hi, phase->intcon(shift_const)));
   412       }
   414       // Get a 0 or -1 from the sign of the dividend.
   415       Node *addend0 = mul_hi;
   416       Node *addend1 = phase->transform(new (phase->C, 3) RShiftLNode(dividend, phase->intcon(N-1)));
   418       // If the divisor is negative, swap the order of the input addends;
   419       // this has the effect of negating the quotient.
   420       if (!d_pos) {
   421         Node *temp = addend0; addend0 = addend1; addend1 = temp;
   422       }
   424       // Adjust the final quotient by subtracting -1 (adding 1)
   425       // from the mul_hi.
   426       q = new (phase->C, 3) SubLNode(addend0, addend1);
   427     }
   428   }
   430   return q;
   431 }
   433 //=============================================================================
   434 //------------------------------Identity---------------------------------------
   435 // If the divisor is 1, we are an identity on the dividend.
   436 Node *DivINode::Identity( PhaseTransform *phase ) {
   437   return (phase->type( in(2) )->higher_equal(TypeInt::ONE)) ? in(1) : this;
   438 }
   440 //------------------------------Idealize---------------------------------------
   441 // Divides can be changed to multiplies and/or shifts
   442 Node *DivINode::Ideal(PhaseGVN *phase, bool can_reshape) {
   443   if (in(0) && remove_dead_region(phase, can_reshape))  return this;
   444   // Don't bother trying to transform a dead node
   445   if( in(0) && in(0)->is_top() )  return NULL;
   447   const Type *t = phase->type( in(2) );
   448   if( t == TypeInt::ONE )       // Identity?
   449     return NULL;                // Skip it
   451   const TypeInt *ti = t->isa_int();
   452   if( !ti ) return NULL;
   453   if( !ti->is_con() ) return NULL;
   454   jint i = ti->get_con();       // Get divisor
   456   if (i == 0) return NULL;      // Dividing by zero constant does not idealize
   458   set_req(0,NULL);              // Dividing by a not-zero constant; no faulting
   460   // Dividing by MININT does not optimize as a power-of-2 shift.
   461   if( i == min_jint ) return NULL;
   463   return transform_int_divide( phase, in(1), i );
   464 }
   466 //------------------------------Value------------------------------------------
   467 // A DivINode divides its inputs.  The third input is a Control input, used to
   468 // prevent hoisting the divide above an unsafe test.
   469 const Type *DivINode::Value( PhaseTransform *phase ) const {
   470   // Either input is TOP ==> the result is TOP
   471   const Type *t1 = phase->type( in(1) );
   472   const Type *t2 = phase->type( in(2) );
   473   if( t1 == Type::TOP ) return Type::TOP;
   474   if( t2 == Type::TOP ) return Type::TOP;
   476   // x/x == 1 since we always generate the dynamic divisor check for 0.
   477   if( phase->eqv( in(1), in(2) ) )
   478     return TypeInt::ONE;
   480   // Either input is BOTTOM ==> the result is the local BOTTOM
   481   const Type *bot = bottom_type();
   482   if( (t1 == bot) || (t2 == bot) ||
   483       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
   484     return bot;
   486   // Divide the two numbers.  We approximate.
   487   // If divisor is a constant and not zero
   488   const TypeInt *i1 = t1->is_int();
   489   const TypeInt *i2 = t2->is_int();
   490   int widen = MAX2(i1->_widen, i2->_widen);
   492   if( i2->is_con() && i2->get_con() != 0 ) {
   493     int32 d = i2->get_con(); // Divisor
   494     jint lo, hi;
   495     if( d >= 0 ) {
   496       lo = i1->_lo/d;
   497       hi = i1->_hi/d;
   498     } else {
   499       if( d == -1 && i1->_lo == min_jint ) {
   500         // 'min_jint/-1' throws arithmetic exception during compilation
   501         lo = min_jint;
   502         // do not support holes, 'hi' must go to either min_jint or max_jint:
   503         // [min_jint, -10]/[-1,-1] ==> [min_jint] UNION [10,max_jint]
   504         hi = i1->_hi == min_jint ? min_jint : max_jint;
   505       } else {
   506         lo = i1->_hi/d;
   507         hi = i1->_lo/d;
   508       }
   509     }
   510     return TypeInt::make(lo, hi, widen);
   511   }
   513   // If the dividend is a constant
   514   if( i1->is_con() ) {
   515     int32 d = i1->get_con();
   516     if( d < 0 ) {
   517       if( d == min_jint ) {
   518         //  (-min_jint) == min_jint == (min_jint / -1)
   519         return TypeInt::make(min_jint, max_jint/2 + 1, widen);
   520       } else {
   521         return TypeInt::make(d, -d, widen);
   522       }
   523     }
   524     return TypeInt::make(-d, d, widen);
   525   }
   527   // Otherwise we give up all hope
   528   return TypeInt::INT;
   529 }
   532 //=============================================================================
   533 //------------------------------Identity---------------------------------------
   534 // If the divisor is 1, we are an identity on the dividend.
   535 Node *DivLNode::Identity( PhaseTransform *phase ) {
   536   return (phase->type( in(2) )->higher_equal(TypeLong::ONE)) ? in(1) : this;
   537 }
   539 //------------------------------Idealize---------------------------------------
   540 // Dividing by a power of 2 is a shift.
   541 Node *DivLNode::Ideal( PhaseGVN *phase, bool can_reshape) {
   542   if (in(0) && remove_dead_region(phase, can_reshape))  return this;
   543   // Don't bother trying to transform a dead node
   544   if( in(0) && in(0)->is_top() )  return NULL;
   546   const Type *t = phase->type( in(2) );
   547   if( t == TypeLong::ONE )      // Identity?
   548     return NULL;                // Skip it
   550   const TypeLong *tl = t->isa_long();
   551   if( !tl ) return NULL;
   552   if( !tl->is_con() ) return NULL;
   553   jlong l = tl->get_con();      // Get divisor
   555   if (l == 0) return NULL;      // Dividing by zero constant does not idealize
   557   set_req(0,NULL);              // Dividing by a not-zero constant; no faulting
   559   // Dividing by MININT does not optimize as a power-of-2 shift.
   560   if( l == min_jlong ) return NULL;
   562   return transform_long_divide( phase, in(1), l );
   563 }
   565 //------------------------------Value------------------------------------------
   566 // A DivLNode divides its inputs.  The third input is a Control input, used to
   567 // prevent hoisting the divide above an unsafe test.
   568 const Type *DivLNode::Value( PhaseTransform *phase ) const {
   569   // Either input is TOP ==> the result is TOP
   570   const Type *t1 = phase->type( in(1) );
   571   const Type *t2 = phase->type( in(2) );
   572   if( t1 == Type::TOP ) return Type::TOP;
   573   if( t2 == Type::TOP ) return Type::TOP;
   575   // x/x == 1 since we always generate the dynamic divisor check for 0.
   576   if( phase->eqv( in(1), in(2) ) )
   577     return TypeLong::ONE;
   579   // Either input is BOTTOM ==> the result is the local BOTTOM
   580   const Type *bot = bottom_type();
   581   if( (t1 == bot) || (t2 == bot) ||
   582       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
   583     return bot;
   585   // Divide the two numbers.  We approximate.
   586   // If divisor is a constant and not zero
   587   const TypeLong *i1 = t1->is_long();
   588   const TypeLong *i2 = t2->is_long();
   589   int widen = MAX2(i1->_widen, i2->_widen);
   591   if( i2->is_con() && i2->get_con() != 0 ) {
   592     jlong d = i2->get_con();    // Divisor
   593     jlong lo, hi;
   594     if( d >= 0 ) {
   595       lo = i1->_lo/d;
   596       hi = i1->_hi/d;
   597     } else {
   598       if( d == CONST64(-1) && i1->_lo == min_jlong ) {
   599         // 'min_jlong/-1' throws arithmetic exception during compilation
   600         lo = min_jlong;
   601         // do not support holes, 'hi' must go to either min_jlong or max_jlong:
   602         // [min_jlong, -10]/[-1,-1] ==> [min_jlong] UNION [10,max_jlong]
   603         hi = i1->_hi == min_jlong ? min_jlong : max_jlong;
   604       } else {
   605         lo = i1->_hi/d;
   606         hi = i1->_lo/d;
   607       }
   608     }
   609     return TypeLong::make(lo, hi, widen);
   610   }
   612   // If the dividend is a constant
   613   if( i1->is_con() ) {
   614     jlong d = i1->get_con();
   615     if( d < 0 ) {
   616       if( d == min_jlong ) {
   617         //  (-min_jlong) == min_jlong == (min_jlong / -1)
   618         return TypeLong::make(min_jlong, max_jlong/2 + 1, widen);
   619       } else {
   620         return TypeLong::make(d, -d, widen);
   621       }
   622     }
   623     return TypeLong::make(-d, d, widen);
   624   }
   626   // Otherwise we give up all hope
   627   return TypeLong::LONG;
   628 }
   631 //=============================================================================
   632 //------------------------------Value------------------------------------------
   633 // An DivFNode divides its inputs.  The third input is a Control input, used to
   634 // prevent hoisting the divide above an unsafe test.
   635 const Type *DivFNode::Value( PhaseTransform *phase ) const {
   636   // Either input is TOP ==> the result is TOP
   637   const Type *t1 = phase->type( in(1) );
   638   const Type *t2 = phase->type( in(2) );
   639   if( t1 == Type::TOP ) return Type::TOP;
   640   if( t2 == Type::TOP ) return Type::TOP;
   642   // Either input is BOTTOM ==> the result is the local BOTTOM
   643   const Type *bot = bottom_type();
   644   if( (t1 == bot) || (t2 == bot) ||
   645       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
   646     return bot;
   648   // x/x == 1, we ignore 0/0.
   649   // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
   650   // Does not work for variables because of NaN's
   651   if( phase->eqv( in(1), in(2) ) && t1->base() == Type::FloatCon)
   652     if (!g_isnan(t1->getf()) && g_isfinite(t1->getf()) && t1->getf() != 0.0) // could be negative ZERO or NaN
   653       return TypeF::ONE;
   655   if( t2 == TypeF::ONE )
   656     return t1;
   658   // If divisor is a constant and not zero, divide them numbers
   659   if( t1->base() == Type::FloatCon &&
   660       t2->base() == Type::FloatCon &&
   661       t2->getf() != 0.0 ) // could be negative zero
   662     return TypeF::make( t1->getf()/t2->getf() );
   664   // If the dividend is a constant zero
   665   // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
   666   // Test TypeF::ZERO is not sufficient as it could be negative zero
   668   if( t1 == TypeF::ZERO && !g_isnan(t2->getf()) && t2->getf() != 0.0 )
   669     return TypeF::ZERO;
   671   // Otherwise we give up all hope
   672   return Type::FLOAT;
   673 }
   675 //------------------------------isA_Copy---------------------------------------
   676 // Dividing by self is 1.
   677 // If the divisor is 1, we are an identity on the dividend.
   678 Node *DivFNode::Identity( PhaseTransform *phase ) {
   679   return (phase->type( in(2) ) == TypeF::ONE) ? in(1) : this;
   680 }
   683 //------------------------------Idealize---------------------------------------
   684 Node *DivFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   685   if (in(0) && remove_dead_region(phase, can_reshape))  return this;
   686   // Don't bother trying to transform a dead node
   687   if( in(0) && in(0)->is_top() )  return NULL;
   689   const Type *t2 = phase->type( in(2) );
   690   if( t2 == TypeF::ONE )         // Identity?
   691     return NULL;                // Skip it
   693   const TypeF *tf = t2->isa_float_constant();
   694   if( !tf ) return NULL;
   695   if( tf->base() != Type::FloatCon ) return NULL;
   697   // Check for out of range values
   698   if( tf->is_nan() || !tf->is_finite() ) return NULL;
   700   // Get the value
   701   float f = tf->getf();
   702   int exp;
   704   // Only for special case of dividing by a power of 2
   705   if( frexp((double)f, &exp) != 0.5 ) return NULL;
   707   // Limit the range of acceptable exponents
   708   if( exp < -126 || exp > 126 ) return NULL;
   710   // Compute the reciprocal
   711   float reciprocal = ((float)1.0) / f;
   713   assert( frexp((double)reciprocal, &exp) == 0.5, "reciprocal should be power of 2" );
   715   // return multiplication by the reciprocal
   716   return (new (phase->C, 3) MulFNode(in(1), phase->makecon(TypeF::make(reciprocal))));
   717 }
   719 //=============================================================================
   720 //------------------------------Value------------------------------------------
   721 // An DivDNode divides its inputs.  The third input is a Control input, used to
   722 // prevent hoisting the divide above an unsafe test.
   723 const Type *DivDNode::Value( PhaseTransform *phase ) const {
   724   // Either input is TOP ==> the result is TOP
   725   const Type *t1 = phase->type( in(1) );
   726   const Type *t2 = phase->type( in(2) );
   727   if( t1 == Type::TOP ) return Type::TOP;
   728   if( t2 == Type::TOP ) return Type::TOP;
   730   // Either input is BOTTOM ==> the result is the local BOTTOM
   731   const Type *bot = bottom_type();
   732   if( (t1 == bot) || (t2 == bot) ||
   733       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
   734     return bot;
   736   // x/x == 1, we ignore 0/0.
   737   // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
   738   // Does not work for variables because of NaN's
   739   if( phase->eqv( in(1), in(2) ) && t1->base() == Type::DoubleCon)
   740     if (!g_isnan(t1->getd()) && g_isfinite(t1->getd()) && t1->getd() != 0.0) // could be negative ZERO or NaN
   741       return TypeD::ONE;
   743   if( t2 == TypeD::ONE )
   744     return t1;
   746 #if defined(IA32)
   747   if (!phase->C->method()->is_strict())
   748     // Can't trust native compilers to properly fold strict double
   749     // division with round-to-zero on this platform.
   750 #endif
   751     {
   752       // If divisor is a constant and not zero, divide them numbers
   753       if( t1->base() == Type::DoubleCon &&
   754           t2->base() == Type::DoubleCon &&
   755           t2->getd() != 0.0 ) // could be negative zero
   756         return TypeD::make( t1->getd()/t2->getd() );
   757     }
   759   // If the dividend is a constant zero
   760   // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
   761   // Test TypeF::ZERO is not sufficient as it could be negative zero
   762   if( t1 == TypeD::ZERO && !g_isnan(t2->getd()) && t2->getd() != 0.0 )
   763     return TypeD::ZERO;
   765   // Otherwise we give up all hope
   766   return Type::DOUBLE;
   767 }
   770 //------------------------------isA_Copy---------------------------------------
   771 // Dividing by self is 1.
   772 // If the divisor is 1, we are an identity on the dividend.
   773 Node *DivDNode::Identity( PhaseTransform *phase ) {
   774   return (phase->type( in(2) ) == TypeD::ONE) ? in(1) : this;
   775 }
   777 //------------------------------Idealize---------------------------------------
   778 Node *DivDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   779   if (in(0) && remove_dead_region(phase, can_reshape))  return this;
   780   // Don't bother trying to transform a dead node
   781   if( in(0) && in(0)->is_top() )  return NULL;
   783   const Type *t2 = phase->type( in(2) );
   784   if( t2 == TypeD::ONE )         // Identity?
   785     return NULL;                // Skip it
   787   const TypeD *td = t2->isa_double_constant();
   788   if( !td ) return NULL;
   789   if( td->base() != Type::DoubleCon ) return NULL;
   791   // Check for out of range values
   792   if( td->is_nan() || !td->is_finite() ) return NULL;
   794   // Get the value
   795   double d = td->getd();
   796   int exp;
   798   // Only for special case of dividing by a power of 2
   799   if( frexp(d, &exp) != 0.5 ) return NULL;
   801   // Limit the range of acceptable exponents
   802   if( exp < -1021 || exp > 1022 ) return NULL;
   804   // Compute the reciprocal
   805   double reciprocal = 1.0 / d;
   807   assert( frexp(reciprocal, &exp) == 0.5, "reciprocal should be power of 2" );
   809   // return multiplication by the reciprocal
   810   return (new (phase->C, 3) MulDNode(in(1), phase->makecon(TypeD::make(reciprocal))));
   811 }
   813 //=============================================================================
   814 //------------------------------Idealize---------------------------------------
   815 Node *ModINode::Ideal(PhaseGVN *phase, bool can_reshape) {
   816   // Check for dead control input
   817   if( in(0) && remove_dead_region(phase, can_reshape) )  return this;
   818   // Don't bother trying to transform a dead node
   819   if( in(0) && in(0)->is_top() )  return NULL;
   821   // Get the modulus
   822   const Type *t = phase->type( in(2) );
   823   if( t == Type::TOP ) return NULL;
   824   const TypeInt *ti = t->is_int();
   826   // Check for useless control input
   827   // Check for excluding mod-zero case
   828   if( in(0) && (ti->_hi < 0 || ti->_lo > 0) ) {
   829     set_req(0, NULL);        // Yank control input
   830     return this;
   831   }
   833   // See if we are MOD'ing by 2^k or 2^k-1.
   834   if( !ti->is_con() ) return NULL;
   835   jint con = ti->get_con();
   837   Node *hook = new (phase->C, 1) Node(1);
   839   // First, special check for modulo 2^k-1
   840   if( con >= 0 && con < max_jint && is_power_of_2(con+1) ) {
   841     uint k = exact_log2(con+1);  // Extract k
   843     // Basic algorithm by David Detlefs.  See fastmod_int.java for gory details.
   844     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*/};
   845     int trip_count = 1;
   846     if( k < ARRAY_SIZE(unroll_factor))  trip_count = unroll_factor[k];
   848     // If the unroll factor is not too large, and if conditional moves are
   849     // ok, then use this case
   850     if( trip_count <= 5 && ConditionalMoveLimit != 0 ) {
   851       Node *x = in(1);            // Value being mod'd
   852       Node *divisor = in(2);      // Also is mask
   854       hook->init_req(0, x);       // Add a use to x to prevent him from dying
   855       // Generate code to reduce X rapidly to nearly 2^k-1.
   856       for( int i = 0; i < trip_count; i++ ) {
   857         Node *xl = phase->transform( new (phase->C, 3) AndINode(x,divisor) );
   858         Node *xh = phase->transform( new (phase->C, 3) RShiftINode(x,phase->intcon(k)) ); // Must be signed
   859         x = phase->transform( new (phase->C, 3) AddINode(xh,xl) );
   860         hook->set_req(0, x);
   861       }
   863       // Generate sign-fixup code.  Was original value positive?
   864       // int hack_res = (i >= 0) ? divisor : 1;
   865       Node *cmp1 = phase->transform( new (phase->C, 3) CmpINode( in(1), phase->intcon(0) ) );
   866       Node *bol1 = phase->transform( new (phase->C, 2) BoolNode( cmp1, BoolTest::ge ) );
   867       Node *cmov1= phase->transform( new (phase->C, 4) CMoveINode(bol1, phase->intcon(1), divisor, TypeInt::POS) );
   868       // if( x >= hack_res ) x -= divisor;
   869       Node *sub  = phase->transform( new (phase->C, 3) SubINode( x, divisor ) );
   870       Node *cmp2 = phase->transform( new (phase->C, 3) CmpINode( x, cmov1 ) );
   871       Node *bol2 = phase->transform( new (phase->C, 2) BoolNode( cmp2, BoolTest::ge ) );
   872       // Convention is to not transform the return value of an Ideal
   873       // since Ideal is expected to return a modified 'this' or a new node.
   874       Node *cmov2= new (phase->C, 4) CMoveINode(bol2, x, sub, TypeInt::INT);
   875       // cmov2 is now the mod
   877       // Now remove the bogus extra edges used to keep things alive
   878       if (can_reshape) {
   879         phase->is_IterGVN()->remove_dead_node(hook);
   880       } else {
   881         hook->set_req(0, NULL);   // Just yank bogus edge during Parse phase
   882       }
   883       return cmov2;
   884     }
   885   }
   887   // Fell thru, the unroll case is not appropriate. Transform the modulo
   888   // into a long multiply/int multiply/subtract case
   890   // Cannot handle mod 0, and min_jint isn't handled by the transform
   891   if( con == 0 || con == min_jint ) return NULL;
   893   // Get the absolute value of the constant; at this point, we can use this
   894   jint pos_con = (con >= 0) ? con : -con;
   896   // integer Mod 1 is always 0
   897   if( pos_con == 1 ) return new (phase->C, 1) ConINode(TypeInt::ZERO);
   899   int log2_con = -1;
   901   // If this is a power of two, they maybe we can mask it
   902   if( is_power_of_2(pos_con) ) {
   903     log2_con = log2_intptr((intptr_t)pos_con);
   905     const Type *dt = phase->type(in(1));
   906     const TypeInt *dti = dt->isa_int();
   908     // See if this can be masked, if the dividend is non-negative
   909     if( dti && dti->_lo >= 0 )
   910       return ( new (phase->C, 3) AndINode( in(1), phase->intcon( pos_con-1 ) ) );
   911   }
   913   // Save in(1) so that it cannot be changed or deleted
   914   hook->init_req(0, in(1));
   916   // Divide using the transform from DivI to MulL
   917   Node *result = transform_int_divide( phase, in(1), pos_con );
   918   if (result != NULL) {
   919     Node *divide = phase->transform(result);
   921     // Re-multiply, using a shift if this is a power of two
   922     Node *mult = NULL;
   924     if( log2_con >= 0 )
   925       mult = phase->transform( new (phase->C, 3) LShiftINode( divide, phase->intcon( log2_con ) ) );
   926     else
   927       mult = phase->transform( new (phase->C, 3) MulINode( divide, phase->intcon( pos_con ) ) );
   929     // Finally, subtract the multiplied divided value from the original
   930     result = new (phase->C, 3) SubINode( in(1), mult );
   931   }
   933   // Now remove the bogus extra edges used to keep things alive
   934   if (can_reshape) {
   935     phase->is_IterGVN()->remove_dead_node(hook);
   936   } else {
   937     hook->set_req(0, NULL);       // Just yank bogus edge during Parse phase
   938   }
   940   // return the value
   941   return result;
   942 }
   944 //------------------------------Value------------------------------------------
   945 const Type *ModINode::Value( PhaseTransform *phase ) const {
   946   // Either input is TOP ==> the result is TOP
   947   const Type *t1 = phase->type( in(1) );
   948   const Type *t2 = phase->type( in(2) );
   949   if( t1 == Type::TOP ) return Type::TOP;
   950   if( t2 == Type::TOP ) return Type::TOP;
   952   // We always generate the dynamic check for 0.
   953   // 0 MOD X is 0
   954   if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
   955   // X MOD X is 0
   956   if( phase->eqv( in(1), in(2) ) ) return TypeInt::ZERO;
   958   // Either input is BOTTOM ==> the result is the local BOTTOM
   959   const Type *bot = bottom_type();
   960   if( (t1 == bot) || (t2 == bot) ||
   961       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
   962     return bot;
   964   const TypeInt *i1 = t1->is_int();
   965   const TypeInt *i2 = t2->is_int();
   966   if( !i1->is_con() || !i2->is_con() ) {
   967     if( i1->_lo >= 0 && i2->_lo >= 0 )
   968       return TypeInt::POS;
   969     // If both numbers are not constants, we know little.
   970     return TypeInt::INT;
   971   }
   972   // Mod by zero?  Throw exception at runtime!
   973   if( !i2->get_con() ) return TypeInt::POS;
   975   // We must be modulo'ing 2 float constants.
   976   // Check for min_jint % '-1', result is defined to be '0'.
   977   if( i1->get_con() == min_jint && i2->get_con() == -1 )
   978     return TypeInt::ZERO;
   980   return TypeInt::make( i1->get_con() % i2->get_con() );
   981 }
   984 //=============================================================================
   985 //------------------------------Idealize---------------------------------------
   986 Node *ModLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   987   // Check for dead control input
   988   if( in(0) && remove_dead_region(phase, can_reshape) )  return this;
   989   // Don't bother trying to transform a dead node
   990   if( in(0) && in(0)->is_top() )  return NULL;
   992   // Get the modulus
   993   const Type *t = phase->type( in(2) );
   994   if( t == Type::TOP ) return NULL;
   995   const TypeLong *tl = t->is_long();
   997   // Check for useless control input
   998   // Check for excluding mod-zero case
   999   if( in(0) && (tl->_hi < 0 || tl->_lo > 0) ) {
  1000     set_req(0, NULL);        // Yank control input
  1001     return this;
  1004   // See if we are MOD'ing by 2^k or 2^k-1.
  1005   if( !tl->is_con() ) return NULL;
  1006   jlong con = tl->get_con();
  1008   Node *hook = new (phase->C, 1) Node(1);
  1010   // Expand mod
  1011   if( con >= 0 && con < max_jlong && is_power_of_2_long(con+1) ) {
  1012     uint k = exact_log2_long(con+1);  // Extract k
  1014     // Basic algorithm by David Detlefs.  See fastmod_long.java for gory details.
  1015     // Used to help a popular random number generator which does a long-mod
  1016     // of 2^31-1 and shows up in SpecJBB and SciMark.
  1017     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*/};
  1018     int trip_count = 1;
  1019     if( k < ARRAY_SIZE(unroll_factor)) trip_count = unroll_factor[k];
  1021     // If the unroll factor is not too large, and if conditional moves are
  1022     // ok, then use this case
  1023     if( trip_count <= 5 && ConditionalMoveLimit != 0 ) {
  1024       Node *x = in(1);            // Value being mod'd
  1025       Node *divisor = in(2);      // Also is mask
  1027       hook->init_req(0, x);       // Add a use to x to prevent him from dying
  1028       // Generate code to reduce X rapidly to nearly 2^k-1.
  1029       for( int i = 0; i < trip_count; i++ ) {
  1030         Node *xl = phase->transform( new (phase->C, 3) AndLNode(x,divisor) );
  1031         Node *xh = phase->transform( new (phase->C, 3) RShiftLNode(x,phase->intcon(k)) ); // Must be signed
  1032         x = phase->transform( new (phase->C, 3) AddLNode(xh,xl) );
  1033         hook->set_req(0, x);    // Add a use to x to prevent him from dying
  1036       // Generate sign-fixup code.  Was original value positive?
  1037       // long hack_res = (i >= 0) ? divisor : CONST64(1);
  1038       Node *cmp1 = phase->transform( new (phase->C, 3) CmpLNode( in(1), phase->longcon(0) ) );
  1039       Node *bol1 = phase->transform( new (phase->C, 2) BoolNode( cmp1, BoolTest::ge ) );
  1040       Node *cmov1= phase->transform( new (phase->C, 4) CMoveLNode(bol1, phase->longcon(1), divisor, TypeLong::LONG) );
  1041       // if( x >= hack_res ) x -= divisor;
  1042       Node *sub  = phase->transform( new (phase->C, 3) SubLNode( x, divisor ) );
  1043       Node *cmp2 = phase->transform( new (phase->C, 3) CmpLNode( x, cmov1 ) );
  1044       Node *bol2 = phase->transform( new (phase->C, 2) BoolNode( cmp2, BoolTest::ge ) );
  1045       // Convention is to not transform the return value of an Ideal
  1046       // since Ideal is expected to return a modified 'this' or a new node.
  1047       Node *cmov2= new (phase->C, 4) CMoveLNode(bol2, x, sub, TypeLong::LONG);
  1048       // cmov2 is now the mod
  1050       // Now remove the bogus extra edges used to keep things alive
  1051       if (can_reshape) {
  1052         phase->is_IterGVN()->remove_dead_node(hook);
  1053       } else {
  1054         hook->set_req(0, NULL);   // Just yank bogus edge during Parse phase
  1056       return cmov2;
  1060   // Fell thru, the unroll case is not appropriate. Transform the modulo
  1061   // into a long multiply/int multiply/subtract case
  1063   // Cannot handle mod 0, and min_jint isn't handled by the transform
  1064   if( con == 0 || con == min_jlong ) return NULL;
  1066   // Get the absolute value of the constant; at this point, we can use this
  1067   jlong pos_con = (con >= 0) ? con : -con;
  1069   // integer Mod 1 is always 0
  1070   if( pos_con == 1 ) return new (phase->C, 1) ConLNode(TypeLong::ZERO);
  1072   int log2_con = -1;
  1074   // If this is a power of two, then maybe we can mask it
  1075   if( is_power_of_2_long(pos_con) ) {
  1076     log2_con = log2_long(pos_con);
  1078     const Type *dt = phase->type(in(1));
  1079     const TypeLong *dtl = dt->isa_long();
  1081     // See if this can be masked, if the dividend is non-negative
  1082     if( dtl && dtl->_lo >= 0 )
  1083       return ( new (phase->C, 3) AndLNode( in(1), phase->longcon( pos_con-1 ) ) );
  1086   // Save in(1) so that it cannot be changed or deleted
  1087   hook->init_req(0, in(1));
  1089   // Divide using the transform from DivI to MulL
  1090   Node *result = transform_long_divide( phase, in(1), pos_con );
  1091   if (result != NULL) {
  1092     Node *divide = phase->transform(result);
  1094     // Re-multiply, using a shift if this is a power of two
  1095     Node *mult = NULL;
  1097     if( log2_con >= 0 )
  1098       mult = phase->transform( new (phase->C, 3) LShiftLNode( divide, phase->intcon( log2_con ) ) );
  1099     else
  1100       mult = phase->transform( new (phase->C, 3) MulLNode( divide, phase->longcon( pos_con ) ) );
  1102     // Finally, subtract the multiplied divided value from the original
  1103     result = new (phase->C, 3) SubLNode( in(1), mult );
  1106   // Now remove the bogus extra edges used to keep things alive
  1107   if (can_reshape) {
  1108     phase->is_IterGVN()->remove_dead_node(hook);
  1109   } else {
  1110     hook->set_req(0, NULL);       // Just yank bogus edge during Parse phase
  1113   // return the value
  1114   return result;
  1117 //------------------------------Value------------------------------------------
  1118 const Type *ModLNode::Value( PhaseTransform *phase ) const {
  1119   // Either input is TOP ==> the result is TOP
  1120   const Type *t1 = phase->type( in(1) );
  1121   const Type *t2 = phase->type( in(2) );
  1122   if( t1 == Type::TOP ) return Type::TOP;
  1123   if( t2 == Type::TOP ) return Type::TOP;
  1125   // We always generate the dynamic check for 0.
  1126   // 0 MOD X is 0
  1127   if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
  1128   // X MOD X is 0
  1129   if( phase->eqv( in(1), in(2) ) ) return TypeLong::ZERO;
  1131   // Either input is BOTTOM ==> the result is the local BOTTOM
  1132   const Type *bot = bottom_type();
  1133   if( (t1 == bot) || (t2 == bot) ||
  1134       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
  1135     return bot;
  1137   const TypeLong *i1 = t1->is_long();
  1138   const TypeLong *i2 = t2->is_long();
  1139   if( !i1->is_con() || !i2->is_con() ) {
  1140     if( i1->_lo >= CONST64(0) && i2->_lo >= CONST64(0) )
  1141       return TypeLong::POS;
  1142     // If both numbers are not constants, we know little.
  1143     return TypeLong::LONG;
  1145   // Mod by zero?  Throw exception at runtime!
  1146   if( !i2->get_con() ) return TypeLong::POS;
  1148   // We must be modulo'ing 2 float constants.
  1149   // Check for min_jint % '-1', result is defined to be '0'.
  1150   if( i1->get_con() == min_jlong && i2->get_con() == -1 )
  1151     return TypeLong::ZERO;
  1153   return TypeLong::make( i1->get_con() % i2->get_con() );
  1157 //=============================================================================
  1158 //------------------------------Value------------------------------------------
  1159 const Type *ModFNode::Value( PhaseTransform *phase ) const {
  1160   // Either input is TOP ==> the result is TOP
  1161   const Type *t1 = phase->type( in(1) );
  1162   const Type *t2 = phase->type( in(2) );
  1163   if( t1 == Type::TOP ) return Type::TOP;
  1164   if( t2 == Type::TOP ) return Type::TOP;
  1166   // Either input is BOTTOM ==> the result is the local BOTTOM
  1167   const Type *bot = bottom_type();
  1168   if( (t1 == bot) || (t2 == bot) ||
  1169       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
  1170     return bot;
  1172   // If either number is not a constant, we know nothing.
  1173   if ((t1->base() != Type::FloatCon) || (t2->base() != Type::FloatCon)) {
  1174     return Type::FLOAT;         // note: x%x can be either NaN or 0
  1177   float f1 = t1->getf();
  1178   float f2 = t2->getf();
  1179   jint  x1 = jint_cast(f1);     // note:  *(int*)&f1, not just (int)f1
  1180   jint  x2 = jint_cast(f2);
  1182   // If either is a NaN, return an input NaN
  1183   if (g_isnan(f1))    return t1;
  1184   if (g_isnan(f2))    return t2;
  1186   // If an operand is infinity or the divisor is +/- zero, punt.
  1187   if (!g_isfinite(f1) || !g_isfinite(f2) || x2 == 0 || x2 == min_jint)
  1188     return Type::FLOAT;
  1190   // We must be modulo'ing 2 float constants.
  1191   // Make sure that the sign of the fmod is equal to the sign of the dividend
  1192   jint xr = jint_cast(fmod(f1, f2));
  1193   if ((x1 ^ xr) < 0) {
  1194     xr ^= min_jint;
  1197   return TypeF::make(jfloat_cast(xr));
  1201 //=============================================================================
  1202 //------------------------------Value------------------------------------------
  1203 const Type *ModDNode::Value( PhaseTransform *phase ) const {
  1204   // Either input is TOP ==> the result is TOP
  1205   const Type *t1 = phase->type( in(1) );
  1206   const Type *t2 = phase->type( in(2) );
  1207   if( t1 == Type::TOP ) return Type::TOP;
  1208   if( t2 == Type::TOP ) return Type::TOP;
  1210   // Either input is BOTTOM ==> the result is the local BOTTOM
  1211   const Type *bot = bottom_type();
  1212   if( (t1 == bot) || (t2 == bot) ||
  1213       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
  1214     return bot;
  1216   // If either number is not a constant, we know nothing.
  1217   if ((t1->base() != Type::DoubleCon) || (t2->base() != Type::DoubleCon)) {
  1218     return Type::DOUBLE;        // note: x%x can be either NaN or 0
  1221   double f1 = t1->getd();
  1222   double f2 = t2->getd();
  1223   jlong  x1 = jlong_cast(f1);   // note:  *(long*)&f1, not just (long)f1
  1224   jlong  x2 = jlong_cast(f2);
  1226   // If either is a NaN, return an input NaN
  1227   if (g_isnan(f1))    return t1;
  1228   if (g_isnan(f2))    return t2;
  1230   // If an operand is infinity or the divisor is +/- zero, punt.
  1231   if (!g_isfinite(f1) || !g_isfinite(f2) || x2 == 0 || x2 == min_jlong)
  1232     return Type::DOUBLE;
  1234   // We must be modulo'ing 2 double constants.
  1235   // Make sure that the sign of the fmod is equal to the sign of the dividend
  1236   jlong xr = jlong_cast(fmod(f1, f2));
  1237   if ((x1 ^ xr) < 0) {
  1238     xr ^= min_jlong;
  1241   return TypeD::make(jdouble_cast(xr));
  1244 //=============================================================================
  1246 DivModNode::DivModNode( Node *c, Node *dividend, Node *divisor ) : MultiNode(3) {
  1247   init_req(0, c);
  1248   init_req(1, dividend);
  1249   init_req(2, divisor);
  1252 //------------------------------make------------------------------------------
  1253 DivModINode* DivModINode::make(Compile* C, Node* div_or_mod) {
  1254   Node* n = div_or_mod;
  1255   assert(n->Opcode() == Op_DivI || n->Opcode() == Op_ModI,
  1256          "only div or mod input pattern accepted");
  1258   DivModINode* divmod = new (C, 3) DivModINode(n->in(0), n->in(1), n->in(2));
  1259   Node*        dproj  = new (C, 1) ProjNode(divmod, DivModNode::div_proj_num);
  1260   Node*        mproj  = new (C, 1) ProjNode(divmod, DivModNode::mod_proj_num);
  1261   return divmod;
  1264 //------------------------------make------------------------------------------
  1265 DivModLNode* DivModLNode::make(Compile* C, Node* div_or_mod) {
  1266   Node* n = div_or_mod;
  1267   assert(n->Opcode() == Op_DivL || n->Opcode() == Op_ModL,
  1268          "only div or mod input pattern accepted");
  1270   DivModLNode* divmod = new (C, 3) DivModLNode(n->in(0), n->in(1), n->in(2));
  1271   Node*        dproj  = new (C, 1) ProjNode(divmod, DivModNode::div_proj_num);
  1272   Node*        mproj  = new (C, 1) ProjNode(divmod, DivModNode::mod_proj_num);
  1273   return divmod;
  1276 //------------------------------match------------------------------------------
  1277 // return result(s) along with their RegMask info
  1278 Node *DivModINode::match( const ProjNode *proj, const Matcher *match ) {
  1279   uint ideal_reg = proj->ideal_reg();
  1280   RegMask rm;
  1281   if (proj->_con == div_proj_num) {
  1282     rm = match->divI_proj_mask();
  1283   } else {
  1284     assert(proj->_con == mod_proj_num, "must be div or mod projection");
  1285     rm = match->modI_proj_mask();
  1287   return new (match->C, 1)MachProjNode(this, proj->_con, rm, ideal_reg);
  1291 //------------------------------match------------------------------------------
  1292 // return result(s) along with their RegMask info
  1293 Node *DivModLNode::match( const ProjNode *proj, const Matcher *match ) {
  1294   uint ideal_reg = proj->ideal_reg();
  1295   RegMask rm;
  1296   if (proj->_con == div_proj_num) {
  1297     rm = match->divL_proj_mask();
  1298   } else {
  1299     assert(proj->_con == mod_proj_num, "must be div or mod projection");
  1300     rm = match->modL_proj_mask();
  1302   return new (match->C, 1)MachProjNode(this, proj->_con, rm, ideal_reg);

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