jdk8-mips64-public/hotspot: src/share/vm/opto/divnode.cpp@a61af66fc99e (annotated)

src/share/vm/opto/divnode.cpp@a61af66fc99e (annotated)

src/share/vm/opto/divnode.cpp

Sat, 01 Dec 2007 00:00:00 +0000

author: duke
date: Sat, 01 Dec 2007 00:00:00 +0000
changeset 435: a61af66fc99e
child 566: 6e825ad773c6
permissions: -rw-r--r--

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 /*
  * Copyright 1997-2006 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 // Portions of code courtesy of Clifford Click
 // Optimization - Graph Style
 #include "incls/_precompiled.incl"
 #include "incls/_divnode.cpp.incl"
 #include <math.h>
 // Implement the integer constant divide -> long multiply transform found in
 //   "Division by Invariant Integers using Multiplication"
 //     by Granlund and Montgomery
 static Node *transform_int_divide_to_long_multiply( PhaseGVN *phase, Node *dividend, int divisor ) {
   // Check for invalid divisors
   assert( divisor != 0 && divisor != min_jint && divisor != 1,
     "bad divisor for transforming to long multiply" );
   // Compute l = ceiling(log2(d))
   //   presumes d is more likely small
   bool d_pos = divisor >= 0;
   int d = d_pos ? divisor : -divisor;
   unsigned ud = (unsigned)d;
   const int N = 32;
   int l = log2_intptr(d-1)+1;
   int sh_post = l;
   const uint64_t U1 = (uint64_t)1;
   // Cliff pointed out how to prevent overflow (from the paper)
   uint64_t m_low  =  (((U1 << l) - ud) << N)                  / ud + (U1 << N);
   uint64_t m_high = ((((U1 << l) - ud) << N) + (U1 << (l+1))) / ud + (U1 << N);
   // Reduce to lowest terms
   for ( ; sh_post > 0; sh_post-- ) {
     uint64_t m_low_1  = m_low  >> 1;
     uint64_t m_high_1 = m_high >> 1;
     if ( m_low_1 >= m_high_1 )
       break;
     m_low  = m_low_1;
     m_high = m_high_1;
   }
   // Result
   Node *q;
   // division by +/- 1
   if (d == 1) {
     // Filtered out as identity above
     if (d_pos)
       return NULL;
     // Just negate the value
     else {
       q = new (phase->C, 3) SubINode(phase->intcon(0), dividend);
     }
   }
   // division by +/- a power of 2
   else if ( is_power_of_2(d) ) {
     // See if we can simply do a shift without rounding
     bool needs_rounding = true;
     const Type *dt = phase->type(dividend);
     const TypeInt *dti = dt->isa_int();
     // we don't need to round a positive dividend
     if (dti && dti->_lo >= 0)
       needs_rounding = false;
     // An AND mask of sufficient size clears the low bits and
     // I can avoid rounding.
     else if( dividend->Opcode() == Op_AndI ) {
       const TypeInt *andconi = phase->type( dividend->in(2) )->isa_int();
       if( andconi && andconi->is_con(-d) ) {
         dividend = dividend->in(1);
         needs_rounding = false;
       }
     }
     // Add rounding to the shift to handle the sign bit
     if( needs_rounding ) {
       Node *t1 = phase->transform(new (phase->C, 3) RShiftINode(dividend, phase->intcon(l - 1)));
       Node *t2 = phase->transform(new (phase->C, 3) URShiftINode(t1, phase->intcon(N - l)));
       dividend = phase->transform(new (phase->C, 3) AddINode(dividend, t2));
     }
     q = new (phase->C, 3) RShiftINode(dividend, phase->intcon(l));
     if (!d_pos)
       q = new (phase->C, 3) SubINode(phase->intcon(0), phase->transform(q));
   }
   // division by something else
   else if (m_high < (U1 << (N-1))) {
     Node *t1 = phase->transform(new (phase->C, 2) ConvI2LNode(dividend));
     Node *t2 = phase->transform(new (phase->C, 3) MulLNode(t1, phase->longcon(m_high)));
     Node *t3 = phase->transform(new (phase->C, 3) RShiftLNode(t2, phase->intcon(sh_post+N)));
     Node *t4 = phase->transform(new (phase->C, 2) ConvL2INode(t3));
     Node *t5 = phase->transform(new (phase->C, 3) RShiftINode(dividend, phase->intcon(N-1)));
     q = new (phase->C, 3) SubINode(d_pos ? t4 : t5, d_pos ? t5 : t4);
   }
   // This handles that case where m_high is >= 2**(N-1). In that case,
   // we subtract out 2**N from the multiply and add it in later as
   // "dividend" in the equation (t5). This case computes the same result
   // as the immediately preceeding case, save that rounding and overflow
   // are accounted for.
   else {
     Node *t1 = phase->transform(new (phase->C, 2) ConvI2LNode(dividend));
     Node *t2 = phase->transform(new (phase->C, 3) MulLNode(t1, phase->longcon(m_high - (U1 << N))));
     Node *t3 = phase->transform(new (phase->C, 3) RShiftLNode(t2, phase->intcon(N)));
     Node *t4 = phase->transform(new (phase->C, 2) ConvL2INode(t3));
     Node *t5 = phase->transform(new (phase->C, 3) AddINode(dividend, t4));
     Node *t6 = phase->transform(new (phase->C, 3) RShiftINode(t5, phase->intcon(sh_post)));
     Node *t7 = phase->transform(new (phase->C, 3) RShiftINode(dividend, phase->intcon(N-1)));
     q = new (phase->C, 3) SubINode(d_pos ? t6 : t7, d_pos ? t7 : t6);
   }
   return (q);
 }
 //=============================================================================
 //------------------------------Identity---------------------------------------
 // If the divisor is 1, we are an identity on the dividend.
 Node *DivINode::Identity( PhaseTransform *phase ) {
   return (phase->type( in(2) )->higher_equal(TypeInt::ONE)) ? in(1) : this;
 }
 //------------------------------Idealize---------------------------------------
 // Divides can be changed to multiplies and/or shifts
 Node *DivINode::Ideal(PhaseGVN *phase, bool can_reshape) {
   if (in(0) && remove_dead_region(phase, can_reshape))  return this;
   const Type *t = phase->type( in(2) );
   if( t == TypeInt::ONE )       // Identity?
     return NULL;                // Skip it
   const TypeInt *ti = t->isa_int();
   if( !ti ) return NULL;
   if( !ti->is_con() ) return NULL;
   int i = ti->get_con();        // Get divisor
   if (i == 0) return NULL;      // Dividing by zero constant does not idealize
   set_req(0,NULL);              // Dividing by a not-zero constant; no faulting
   // Dividing by MININT does not optimize as a power-of-2 shift.
   if( i == min_jint ) return NULL;
   return transform_int_divide_to_long_multiply( phase, in(1), i );
 }
 //------------------------------Value------------------------------------------
 // A DivINode divides its inputs.  The third input is a Control input, used to
 // prevent hoisting the divide above an unsafe test.
 const Type *DivINode::Value( PhaseTransform *phase ) const {
   // Either input is TOP ==> the result is TOP
   const Type *t1 = phase->type( in(1) );
   const Type *t2 = phase->type( in(2) );
   if( t1 == Type::TOP ) return Type::TOP;
   if( t2 == Type::TOP ) return Type::TOP;
   // x/x == 1 since we always generate the dynamic divisor check for 0.
   if( phase->eqv( in(1), in(2) ) )
     return TypeInt::ONE;
   // Either input is BOTTOM ==> the result is the local BOTTOM
   const Type *bot = bottom_type();
   if( (t1 == bot) || (t2 == bot) ||
       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
     return bot;
   // Divide the two numbers.  We approximate.
   // If divisor is a constant and not zero
   const TypeInt *i1 = t1->is_int();
   const TypeInt *i2 = t2->is_int();
   int widen = MAX2(i1->_widen, i2->_widen);
   if( i2->is_con() && i2->get_con() != 0 ) {
     int32 d = i2->get_con(); // Divisor
     jint lo, hi;
     if( d >= 0 ) {
       lo = i1->_lo/d;
       hi = i1->_hi/d;
     } else {
       if( d == -1 && i1->_lo == min_jint ) {
         // 'min_jint/-1' throws arithmetic exception during compilation
         lo = min_jint;
         // do not support holes, 'hi' must go to either min_jint or max_jint:
         // [min_jint, -10]/[-1,-1] ==> [min_jint] UNION [10,max_jint]
         hi = i1->_hi == min_jint ? min_jint : max_jint;
       } else {
         lo = i1->_hi/d;
         hi = i1->_lo/d;
       }
     }
     return TypeInt::make(lo, hi, widen);
   }
   // If the dividend is a constant
   if( i1->is_con() ) {
     int32 d = i1->get_con();
     if( d < 0 ) {
       if( d == min_jint ) {
         //  (-min_jint) == min_jint == (min_jint / -1)
         return TypeInt::make(min_jint, max_jint/2 + 1, widen);
       } else {
         return TypeInt::make(d, -d, widen);
       }
     }
     return TypeInt::make(-d, d, widen);
   }
   // Otherwise we give up all hope
   return TypeInt::INT;
 }
 //=============================================================================
 //------------------------------Identity---------------------------------------
 // If the divisor is 1, we are an identity on the dividend.
 Node *DivLNode::Identity( PhaseTransform *phase ) {
   return (phase->type( in(2) )->higher_equal(TypeLong::ONE)) ? in(1) : this;
 }
 //------------------------------Idealize---------------------------------------
 // Dividing by a power of 2 is a shift.
 Node *DivLNode::Ideal( PhaseGVN *phase, bool can_reshape) {
   if (in(0) && remove_dead_region(phase, can_reshape))  return this;
   const Type *t = phase->type( in(2) );
   if( t == TypeLong::ONE )       // Identity?
     return NULL;                // Skip it
   const TypeLong *ti = t->isa_long();
   if( !ti ) return NULL;
   if( !ti->is_con() ) return NULL;
   jlong i = ti->get_con();      // Get divisor
   if( i ) set_req(0, NULL);     // Dividing by a not-zero constant; no faulting
   // Dividing by MININT does not optimize as a power-of-2 shift.
   if( i == min_jlong ) return NULL;
   // Check for negative power of 2 divisor, if so, negate it and set a flag
   // to indicate result needs to be negated.  Note that negating the dividend
   // here does not work when it has the value MININT
   Node *dividend = in(1);
   bool negate_res = false;
   if (is_power_of_2_long(-i)) {
     i = -i;                     // Flip divisor
     negate_res = true;
   }
   // Check for power of 2
   if (!is_power_of_2_long(i))   // Is divisor a power of 2?
     return NULL;                // Not a power of 2
   // Compute number of bits to shift
   int log_i = log2_long(i);
   // See if we can simply do a shift without rounding
   bool needs_rounding = true;
   const Type *dt = phase->type(dividend);
   const TypeLong *dtl = dt->isa_long();
   if (dtl && dtl->_lo > 0) {
     // we don't need to round a positive dividend
     needs_rounding = false;
   } else if( dividend->Opcode() == Op_AndL ) {
     // An AND mask of sufficient size clears the low bits and
     // I can avoid rounding.
     const TypeLong *andconi = phase->type( dividend->in(2) )->isa_long();
     if( andconi &&
         andconi->is_con() &&
         andconi->get_con() == -i ) {
       dividend = dividend->in(1);
       needs_rounding = false;
     }
   }
   if (!needs_rounding) {
     Node *result = new (phase->C, 3) RShiftLNode(dividend, phase->intcon(log_i));
     if (negate_res) {
       result = phase->transform(result);
       result = new (phase->C, 3) SubLNode(phase->longcon(0), result);
     }
     return result;
   }
   // Divide-by-power-of-2 can be made into a shift, but you have to do
   // more math for the rounding.  You need to add 0 for positive
   // numbers, and "i-1" for negative numbers.  Example: i=4, so the
   // shift is by 2.  You need to add 3 to negative dividends and 0 to
   // positive ones.  So (-7+3)>>2 becomes -1, (-4+3)>>2 becomes -1,
   // (-2+3)>>2 becomes 0, etc.
   // Compute 0 or -1, based on sign bit
   Node *sign = phase->transform(new (phase->C, 3) RShiftLNode(dividend,phase->intcon(63)));
   // Mask sign bit to the low sign bits
   Node *round = phase->transform(new (phase->C, 3) AndLNode(sign,phase->longcon(i-1)));
   // Round up before shifting
   Node *sum = phase->transform(new (phase->C, 3) AddLNode(dividend,round));
   // Shift for division
   Node *result = new (phase->C, 3) RShiftLNode(sum, phase->intcon(log_i));
   if (negate_res) {
     result = phase->transform(result);
     result = new (phase->C, 3) SubLNode(phase->longcon(0), result);
   }
   return result;
 }
 //------------------------------Value------------------------------------------
 // A DivLNode divides its inputs.  The third input is a Control input, used to
 // prevent hoisting the divide above an unsafe test.
 const Type *DivLNode::Value( PhaseTransform *phase ) const {
   // Either input is TOP ==> the result is TOP
   const Type *t1 = phase->type( in(1) );
   const Type *t2 = phase->type( in(2) );
   if( t1 == Type::TOP ) return Type::TOP;
   if( t2 == Type::TOP ) return Type::TOP;
   // x/x == 1 since we always generate the dynamic divisor check for 0.
   if( phase->eqv( in(1), in(2) ) )
     return TypeLong::ONE;
   // Either input is BOTTOM ==> the result is the local BOTTOM
   const Type *bot = bottom_type();
   if( (t1 == bot) || (t2 == bot) ||
       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
     return bot;
   // Divide the two numbers.  We approximate.
   // If divisor is a constant and not zero
   const TypeLong *i1 = t1->is_long();
   const TypeLong *i2 = t2->is_long();
   int widen = MAX2(i1->_widen, i2->_widen);
   if( i2->is_con() && i2->get_con() != 0 ) {
     jlong d = i2->get_con();    // Divisor
     jlong lo, hi;
     if( d >= 0 ) {
       lo = i1->_lo/d;
       hi = i1->_hi/d;
     } else {
       if( d == CONST64(-1) && i1->_lo == min_jlong ) {
         // 'min_jlong/-1' throws arithmetic exception during compilation
         lo = min_jlong;
         // do not support holes, 'hi' must go to either min_jlong or max_jlong:
         // [min_jlong, -10]/[-1,-1] ==> [min_jlong] UNION [10,max_jlong]
         hi = i1->_hi == min_jlong ? min_jlong : max_jlong;
       } else {
         lo = i1->_hi/d;
         hi = i1->_lo/d;
       }
     }
     return TypeLong::make(lo, hi, widen);
   }
   // If the dividend is a constant
   if( i1->is_con() ) {
     jlong d = i1->get_con();
     if( d < 0 ) {
       if( d == min_jlong ) {
         //  (-min_jlong) == min_jlong == (min_jlong / -1)
         return TypeLong::make(min_jlong, max_jlong/2 + 1, widen);
       } else {
         return TypeLong::make(d, -d, widen);
       }
     }
     return TypeLong::make(-d, d, widen);
   }
   // Otherwise we give up all hope
   return TypeLong::LONG;
 }
 //=============================================================================
 //------------------------------Value------------------------------------------
 // An DivFNode divides its inputs.  The third input is a Control input, used to
 // prevent hoisting the divide above an unsafe test.
 const Type *DivFNode::Value( PhaseTransform *phase ) const {
   // Either input is TOP ==> the result is TOP
   const Type *t1 = phase->type( in(1) );
   const Type *t2 = phase->type( in(2) );
   if( t1 == Type::TOP ) return Type::TOP;
   if( t2 == Type::TOP ) return Type::TOP;
   // Either input is BOTTOM ==> the result is the local BOTTOM
   const Type *bot = bottom_type();
   if( (t1 == bot) || (t2 == bot) ||
       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
     return bot;
   // x/x == 1, we ignore 0/0.
   // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
   // does not work for variables because of NaN's
   if( phase->eqv( in(1), in(2) ) && t1->base() == Type::FloatCon)
     if (!g_isnan(t1->getf()) && g_isfinite(t1->getf()) && t1->getf() != 0.0) // could be negative ZERO or NaN
       return TypeF::ONE;
   if( t2 == TypeF::ONE )
     return t1;
   // If divisor is a constant and not zero, divide them numbers
   if( t1->base() == Type::FloatCon &&
       t2->base() == Type::FloatCon &&
       t2->getf() != 0.0 ) // could be negative zero
     return TypeF::make( t1->getf()/t2->getf() );
   // If the dividend is a constant zero
   // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
   // Test TypeF::ZERO is not sufficient as it could be negative zero
   if( t1 == TypeF::ZERO && !g_isnan(t2->getf()) && t2->getf() != 0.0 )
     return TypeF::ZERO;
   // Otherwise we give up all hope
   return Type::FLOAT;
 }
 //------------------------------isA_Copy---------------------------------------
 // Dividing by self is 1.
 // If the divisor is 1, we are an identity on the dividend.
 Node *DivFNode::Identity( PhaseTransform *phase ) {
   return (phase->type( in(2) ) == TypeF::ONE) ? in(1) : this;
 }
 //------------------------------Idealize---------------------------------------
 Node *DivFNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   if (in(0) && remove_dead_region(phase, can_reshape))  return this;
   const Type *t2 = phase->type( in(2) );
   if( t2 == TypeF::ONE )         // Identity?
     return NULL;                // Skip it
   const TypeF *tf = t2->isa_float_constant();
   if( !tf ) return NULL;
   if( tf->base() != Type::FloatCon ) return NULL;
   // Check for out of range values
   if( tf->is_nan() || !tf->is_finite() ) return NULL;
   // Get the value
   float f = tf->getf();
   int exp;
   // Only for special case of dividing by a power of 2
   if( frexp((double)f, &exp) != 0.5 ) return NULL;
   // Limit the range of acceptable exponents
   if( exp < -126 || exp > 126 ) return NULL;
   // Compute the reciprocal
   float reciprocal = ((float)1.0) / f;
   assert( frexp((double)reciprocal, &exp) == 0.5, "reciprocal should be power of 2" );
   // return multiplication by the reciprocal
   return (new (phase->C, 3) MulFNode(in(1), phase->makecon(TypeF::make(reciprocal))));
 }
 //=============================================================================
 //------------------------------Value------------------------------------------
 // An DivDNode divides its inputs.  The third input is a Control input, used to
 // prvent hoisting the divide above an unsafe test.
 const Type *DivDNode::Value( PhaseTransform *phase ) const {
   // Either input is TOP ==> the result is TOP
   const Type *t1 = phase->type( in(1) );
   const Type *t2 = phase->type( in(2) );
   if( t1 == Type::TOP ) return Type::TOP;
   if( t2 == Type::TOP ) return Type::TOP;
   // Either input is BOTTOM ==> the result is the local BOTTOM
   const Type *bot = bottom_type();
   if( (t1 == bot) || (t2 == bot) ||
       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
     return bot;
   // x/x == 1, we ignore 0/0.
   // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
   // Does not work for variables because of NaN's
   if( phase->eqv( in(1), in(2) ) && t1->base() == Type::DoubleCon)
     if (!g_isnan(t1->getd()) && g_isfinite(t1->getd()) && t1->getd() != 0.0) // could be negative ZERO or NaN
       return TypeD::ONE;
   if( t2 == TypeD::ONE )
     return t1;
   // If divisor is a constant and not zero, divide them numbers
   if( t1->base() == Type::DoubleCon &&
       t2->base() == Type::DoubleCon &&
       t2->getd() != 0.0 ) // could be negative zero
     return TypeD::make( t1->getd()/t2->getd() );
   // If the dividend is a constant zero
   // Note: if t1 and t2 are zero then result is NaN (JVMS page 213)
   // Test TypeF::ZERO is not sufficient as it could be negative zero
   if( t1 == TypeD::ZERO && !g_isnan(t2->getd()) && t2->getd() != 0.0 )
     return TypeD::ZERO;
   // Otherwise we give up all hope
   return Type::DOUBLE;
 }
 //------------------------------isA_Copy---------------------------------------
 // Dividing by self is 1.
 // If the divisor is 1, we are an identity on the dividend.
 Node *DivDNode::Identity( PhaseTransform *phase ) {
   return (phase->type( in(2) ) == TypeD::ONE) ? in(1) : this;
 }
 //------------------------------Idealize---------------------------------------
 Node *DivDNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   if (in(0) && remove_dead_region(phase, can_reshape))  return this;
   const Type *t2 = phase->type( in(2) );
   if( t2 == TypeD::ONE )         // Identity?
     return NULL;                // Skip it
   const TypeD *td = t2->isa_double_constant();
   if( !td ) return NULL;
   if( td->base() != Type::DoubleCon ) return NULL;
   // Check for out of range values
   if( td->is_nan() || !td->is_finite() ) return NULL;
   // Get the value
   double d = td->getd();
   int exp;
   // Only for special case of dividing by a power of 2
   if( frexp(d, &exp) != 0.5 ) return NULL;
   // Limit the range of acceptable exponents
   if( exp < -1021 || exp > 1022 ) return NULL;
   // Compute the reciprocal
   double reciprocal = 1.0 / d;
   assert( frexp(reciprocal, &exp) == 0.5, "reciprocal should be power of 2" );
   // return multiplication by the reciprocal
   return (new (phase->C, 3) MulDNode(in(1), phase->makecon(TypeD::make(reciprocal))));
 }
 //=============================================================================
 //------------------------------Idealize---------------------------------------
 Node *ModINode::Ideal(PhaseGVN *phase, bool can_reshape) {
   // Check for dead control input
   if( remove_dead_region(phase, can_reshape) )  return this;
   // Get the modulus
   const Type *t = phase->type( in(2) );
   if( t == Type::TOP ) return NULL;
   const TypeInt *ti = t->is_int();
   // Check for useless control input
   // Check for excluding mod-zero case
   if( in(0) && (ti->_hi < 0 || ti->_lo > 0) ) {
     set_req(0, NULL);        // Yank control input
     return this;
   }
   // See if we are MOD'ing by 2^k or 2^k-1.
   if( !ti->is_con() ) return NULL;
   jint con = ti->get_con();
   Node *hook = new (phase->C, 1) Node(1);
   // First, special check for modulo 2^k-1
   if( con >= 0 && con < max_jint && is_power_of_2(con+1) ) {
     uint k = exact_log2(con+1);  // Extract k
     // Basic algorithm by David Detlefs.  See fastmod_int.java for gory details.
     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*/};
     int trip_count = 1;
     if( k < ARRAY_SIZE(unroll_factor))  trip_count = unroll_factor[k];
     // If the unroll factor is not too large, and if conditional moves are
     // ok, then use this case
     if( trip_count <= 5 && ConditionalMoveLimit != 0 ) {
       Node *x = in(1);            // Value being mod'd
       Node *divisor = in(2);      // Also is mask
       hook->init_req(0, x);       // Add a use to x to prevent him from dying
       // Generate code to reduce X rapidly to nearly 2^k-1.
       for( int i = 0; i < trip_count; i++ ) {
           Node *xl = phase->transform( new (phase->C, 3) AndINode(x,divisor) );
           Node *xh = phase->transform( new (phase->C, 3) RShiftINode(x,phase->intcon(k)) ); // Must be signed
           x = phase->transform( new (phase->C, 3) AddINode(xh,xl) );
           hook->set_req(0, x);
       }
       // Generate sign-fixup code.  Was original value positive?
       // int hack_res = (i >= 0) ? divisor : 1;
       Node *cmp1 = phase->transform( new (phase->C, 3) CmpINode( in(1), phase->intcon(0) ) );
       Node *bol1 = phase->transform( new (phase->C, 2) BoolNode( cmp1, BoolTest::ge ) );
       Node *cmov1= phase->transform( new (phase->C, 4) CMoveINode(bol1, phase->intcon(1), divisor, TypeInt::POS) );
       // if( x >= hack_res ) x -= divisor;
       Node *sub  = phase->transform( new (phase->C, 3) SubINode( x, divisor ) );
       Node *cmp2 = phase->transform( new (phase->C, 3) CmpINode( x, cmov1 ) );
       Node *bol2 = phase->transform( new (phase->C, 2) BoolNode( cmp2, BoolTest::ge ) );
       // Convention is to not transform the return value of an Ideal
       // since Ideal is expected to return a modified 'this' or a new node.
       Node *cmov2= new (phase->C, 4) CMoveINode(bol2, x, sub, TypeInt::INT);
       // cmov2 is now the mod
       // Now remove the bogus extra edges used to keep things alive
       if (can_reshape) {
         phase->is_IterGVN()->remove_dead_node(hook);
       } else {
         hook->set_req(0, NULL);   // Just yank bogus edge during Parse phase
       }
       return cmov2;
     }
   }
   // Fell thru, the unroll case is not appropriate. Transform the modulo
   // into a long multiply/int multiply/subtract case
   // Cannot handle mod 0, and min_jint isn't handled by the transform
   if( con == 0 || con == min_jint ) return NULL;
   // Get the absolute value of the constant; at this point, we can use this
   jint pos_con = (con >= 0) ? con : -con;
   // integer Mod 1 is always 0
   if( pos_con == 1 ) return new (phase->C, 1) ConINode(TypeInt::ZERO);
   int log2_con = -1;
   // If this is a power of two, they maybe we can mask it
   if( is_power_of_2(pos_con) ) {
     log2_con = log2_intptr((intptr_t)pos_con);
     const Type *dt = phase->type(in(1));
     const TypeInt *dti = dt->isa_int();
     // See if this can be masked, if the dividend is non-negative
     if( dti && dti->_lo >= 0 )
       return ( new (phase->C, 3) AndINode( in(1), phase->intcon( pos_con-1 ) ) );
   }
   // Save in(1) so that it cannot be changed or deleted
   hook->init_req(0, in(1));
   // Divide using the transform from DivI to MulL
   Node *divide = phase->transform( transform_int_divide_to_long_multiply( phase, in(1), pos_con ) );
   // Re-multiply, using a shift if this is a power of two
   Node *mult = NULL;
   if( log2_con >= 0 )
     mult = phase->transform( new (phase->C, 3) LShiftINode( divide, phase->intcon( log2_con ) ) );
   else
     mult = phase->transform( new (phase->C, 3) MulINode( divide, phase->intcon( pos_con ) ) );
   // Finally, subtract the multiplied divided value from the original
   Node *result = new (phase->C, 3) SubINode( in(1), mult );
   // Now remove the bogus extra edges used to keep things alive
   if (can_reshape) {
     phase->is_IterGVN()->remove_dead_node(hook);
   } else {
     hook->set_req(0, NULL);       // Just yank bogus edge during Parse phase
   }
   // return the value
   return result;
 }
 //------------------------------Value------------------------------------------
 const Type *ModINode::Value( PhaseTransform *phase ) const {
   // Either input is TOP ==> the result is TOP
   const Type *t1 = phase->type( in(1) );
   const Type *t2 = phase->type( in(2) );
   if( t1 == Type::TOP ) return Type::TOP;
   if( t2 == Type::TOP ) return Type::TOP;
   // We always generate the dynamic check for 0.
   // 0 MOD X is 0
   if( t1 == TypeInt::ZERO ) return TypeInt::ZERO;
   // X MOD X is 0
   if( phase->eqv( in(1), in(2) ) ) return TypeInt::ZERO;
   // Either input is BOTTOM ==> the result is the local BOTTOM
   const Type *bot = bottom_type();
   if( (t1 == bot) || (t2 == bot) ||
       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
     return bot;
   const TypeInt *i1 = t1->is_int();
   const TypeInt *i2 = t2->is_int();
   if( !i1->is_con() || !i2->is_con() ) {
     if( i1->_lo >= 0 && i2->_lo >= 0 )
       return TypeInt::POS;
     // If both numbers are not constants, we know little.
     return TypeInt::INT;
   }
   // Mod by zero?  Throw exception at runtime!
   if( !i2->get_con() ) return TypeInt::POS;
   // We must be modulo'ing 2 float constants.
   // Check for min_jint % '-1', result is defined to be '0'.
   if( i1->get_con() == min_jint && i2->get_con() == -1 )
     return TypeInt::ZERO;
   return TypeInt::make( i1->get_con() % i2->get_con() );
 }
 //=============================================================================
 //------------------------------Idealize---------------------------------------
 Node *ModLNode::Ideal(PhaseGVN *phase, bool can_reshape) {
   // Check for dead control input
   if( remove_dead_region(phase, can_reshape) )  return this;
   // Get the modulus
   const Type *t = phase->type( in(2) );
   if( t == Type::TOP ) return NULL;
   const TypeLong *ti = t->is_long();
   // Check for useless control input
   // Check for excluding mod-zero case
   if( in(0) && (ti->_hi < 0 || ti->_lo > 0) ) {
     set_req(0, NULL);        // Yank control input
     return this;
   }
   // See if we are MOD'ing by 2^k or 2^k-1.
   if( !ti->is_con() ) return NULL;
   jlong con = ti->get_con();
   bool m1 = false;
   if( !is_power_of_2_long(con) ) {      // Not 2^k
     if( !is_power_of_2_long(con+1) ) // Not 2^k-1?
       return NULL;              // No interesting mod hacks
     m1 = true;                  // Found 2^k-1
     con++;                      // Convert to 2^k form
   }
   uint k = log2_long(con);       // Extract k
   // Expand mod
   if( !m1 ) {                   // Case 2^k
   } else {                      // Case 2^k-1
     // Basic algorithm by David Detlefs.  See fastmod_long.java for gory details.
     // Used to help a popular random number generator which does a long-mod
     // of 2^31-1 and shows up in SpecJBB and SciMark.
     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*/};
     int trip_count = 1;
     if( k < ARRAY_SIZE(unroll_factor)) trip_count = unroll_factor[k];
     if( trip_count > 4 ) return NULL; // Too much unrolling
     if (ConditionalMoveLimit == 0) return NULL;  // cmov is required
     Node *x = in(1);            // Value being mod'd
     Node *divisor = in(2);      // Also is mask
     Node *hook = new (phase->C, 1) Node(x);
     // Generate code to reduce X rapidly to nearly 2^k-1.
     for( int i = 0; i < trip_count; i++ ) {
         Node *xl = phase->transform( new (phase->C, 3) AndLNode(x,divisor) );
         Node *xh = phase->transform( new (phase->C, 3) RShiftLNode(x,phase->intcon(k)) ); // Must be signed
         x = phase->transform( new (phase->C, 3) AddLNode(xh,xl) );
         hook->set_req(0, x);    // Add a use to x to prevent him from dying
     }
     // Generate sign-fixup code.  Was original value positive?
     // long hack_res = (i >= 0) ? divisor : CONST64(1);
     Node *cmp1 = phase->transform( new (phase->C, 3) CmpLNode( in(1), phase->longcon(0) ) );
     Node *bol1 = phase->transform( new (phase->C, 2) BoolNode( cmp1, BoolTest::ge ) );
     Node *cmov1= phase->transform( new (phase->C, 4) CMoveLNode(bol1, phase->longcon(1), divisor, TypeLong::LONG) );
     // if( x >= hack_res ) x -= divisor;
     Node *sub  = phase->transform( new (phase->C, 3) SubLNode( x, divisor ) );
     Node *cmp2 = phase->transform( new (phase->C, 3) CmpLNode( x, cmov1 ) );
     Node *bol2 = phase->transform( new (phase->C, 2) BoolNode( cmp2, BoolTest::ge ) );
     // Convention is to not transform the return value of an Ideal
     // since Ideal is expected to return a modified 'this' or a new node.
     Node *cmov2= new (phase->C, 4) CMoveLNode(bol2, x, sub, TypeLong::LONG);
     // cmov2 is now the mod
     // Now remove the bogus extra edges used to keep things alive
     if (can_reshape) {
       phase->is_IterGVN()->remove_dead_node(hook);
     } else {
       hook->set_req(0, NULL);   // Just yank bogus edge during Parse phase
     }
     return cmov2;
   }
   return NULL;
 }
 //------------------------------Value------------------------------------------
 const Type *ModLNode::Value( PhaseTransform *phase ) const {
   // Either input is TOP ==> the result is TOP
   const Type *t1 = phase->type( in(1) );
   const Type *t2 = phase->type( in(2) );
   if( t1 == Type::TOP ) return Type::TOP;
   if( t2 == Type::TOP ) return Type::TOP;
   // We always generate the dynamic check for 0.
   // 0 MOD X is 0
   if( t1 == TypeLong::ZERO ) return TypeLong::ZERO;
   // X MOD X is 0
   if( phase->eqv( in(1), in(2) ) ) return TypeLong::ZERO;
   // Either input is BOTTOM ==> the result is the local BOTTOM
   const Type *bot = bottom_type();
   if( (t1 == bot) || (t2 == bot) ||
       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
     return bot;
   const TypeLong *i1 = t1->is_long();
   const TypeLong *i2 = t2->is_long();
   if( !i1->is_con() || !i2->is_con() ) {
     if( i1->_lo >= CONST64(0) && i2->_lo >= CONST64(0) )
       return TypeLong::POS;
     // If both numbers are not constants, we know little.
     return TypeLong::LONG;
   }
   // Mod by zero?  Throw exception at runtime!
   if( !i2->get_con() ) return TypeLong::POS;
   // We must be modulo'ing 2 float constants.
   // Check for min_jint % '-1', result is defined to be '0'.
   if( i1->get_con() == min_jlong && i2->get_con() == -1 )
     return TypeLong::ZERO;
   return TypeLong::make( i1->get_con() % i2->get_con() );
 }
 //=============================================================================
 //------------------------------Value------------------------------------------
 const Type *ModFNode::Value( PhaseTransform *phase ) const {
   // Either input is TOP ==> the result is TOP
   const Type *t1 = phase->type( in(1) );
   const Type *t2 = phase->type( in(2) );
   if( t1 == Type::TOP ) return Type::TOP;
   if( t2 == Type::TOP ) return Type::TOP;
   // Either input is BOTTOM ==> the result is the local BOTTOM
   const Type *bot = bottom_type();
   if( (t1 == bot) || (t2 == bot) ||
       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
     return bot;
   // If either is a NaN, return an input NaN
   if( g_isnan(t1->getf()) )    return t1;
   if( g_isnan(t2->getf()) )    return t2;
   // It is not worth trying to constant fold this stuff!
   return Type::FLOAT;
   /*
   // If dividend is infinity or divisor is zero, or both, the result is NaN
   if( !g_isfinite(t1->getf()) || ((t2->getf() == 0.0) || (jint_cast(t2->getf()) == 0x80000000)) )
   // X MOD infinity = X
   if( !g_isfinite(t2->getf()) && !g_isnan(t2->getf()) ) return t1;
   // 0 MOD finite = dividend (positive or negative zero)
   // Not valid for: NaN MOD any; any MOD nan; 0 MOD 0; or for 0 MOD NaN
   // NaNs are handled previously.
   if( !(t2->getf() == 0.0) && !((int)t2->getf() == 0x80000000)) {
     if (((t1->getf() == 0.0) || ((int)t1->getf() == 0x80000000)) && g_isfinite(t2->getf()) ) {
       return t1;
     }
   }
   // X MOD X is 0
   // Does not work for variables because of NaN's
   if( phase->eqv( in(1), in(2) ) && t1->base() == Type::FloatCon)
     if (!g_isnan(t1->getf()) && (t1->getf() != 0.0) && ((int)t1->getf() != 0x80000000)) {
       if(t1->getf() < 0.0) {
         float result = jfloat_cast(0x80000000);
         return TypeF::make( result );
       }
       else
         return TypeF::ZERO;
     }
   // If both numbers are not constants, we know nothing.
   if( (t1->base() != Type::FloatCon) || (t2->base() != Type::FloatCon) )
     return Type::FLOAT;
   // We must be modulo'ing 2 float constants.
   // Make sure that the sign of the fmod is equal to the sign of the dividend
   float result = (float)fmod( t1->getf(), t2->getf() );
   float dividend = t1->getf();
   if( (dividend < 0.0) || ((int)dividend == 0x80000000) ) {
     if( result > 0.0 )
       result = 0.0 - result;
     else if( result == 0.0 ) {
       result = jfloat_cast(0x80000000);
     }
   }
   return TypeF::make( result );
   */
 }
 //=============================================================================
 //------------------------------Value------------------------------------------
 const Type *ModDNode::Value( PhaseTransform *phase ) const {
   // Either input is TOP ==> the result is TOP
   const Type *t1 = phase->type( in(1) );
   const Type *t2 = phase->type( in(2) );
   if( t1 == Type::TOP ) return Type::TOP;
   if( t2 == Type::TOP ) return Type::TOP;
   // Either input is BOTTOM ==> the result is the local BOTTOM
   const Type *bot = bottom_type();
   if( (t1 == bot) || (t2 == bot) ||
       (t1 == Type::BOTTOM) || (t2 == Type::BOTTOM) )
     return bot;
   // If either is a NaN, return an input NaN
   if( g_isnan(t1->getd()) )    return t1;
   if( g_isnan(t2->getd()) )    return t2;
   // X MOD infinity = X
   if( !g_isfinite(t2->getd())) return t1;
   // 0 MOD finite = dividend (positive or negative zero)
   // Not valid for: NaN MOD any; any MOD nan; 0 MOD 0; or for 0 MOD NaN
   // NaNs are handled previously.
   if( !(t2->getd() == 0.0) ) {
     if( t1->getd() == 0.0 && g_isfinite(t2->getd()) ) {
       return t1;
     }
   }
   // X MOD X is 0
   // does not work for variables because of NaN's
   if( phase->eqv( in(1), in(2) ) && t1->base() == Type::DoubleCon )
     if (!g_isnan(t1->getd()) && t1->getd() != 0.0)
       return TypeD::ZERO;
   // If both numbers are not constants, we know nothing.
   if( (t1->base() != Type::DoubleCon) || (t2->base() != Type::DoubleCon) )
     return Type::DOUBLE;
   // We must be modulo'ing 2 double constants.
   return TypeD::make( fmod( t1->getd(), t2->getd() ) );
 }
 //=============================================================================
 DivModNode::DivModNode( Node *c, Node *dividend, Node *divisor ) : MultiNode(3) {
   init_req(0, c);
   init_req(1, dividend);
   init_req(2, divisor);
 }
 //------------------------------make------------------------------------------
 DivModINode* DivModINode::make(Compile* C, Node* div_or_mod) {
   Node* n = div_or_mod;
   assert(n->Opcode() == Op_DivI || n->Opcode() == Op_ModI,
          "only div or mod input pattern accepted");
   DivModINode* divmod = new (C, 3) DivModINode(n->in(0), n->in(1), n->in(2));
   Node*        dproj  = new (C, 1) ProjNode(divmod, DivModNode::div_proj_num);
   Node*        mproj  = new (C, 1) ProjNode(divmod, DivModNode::mod_proj_num);
   return divmod;
 }
 //------------------------------make------------------------------------------
 DivModLNode* DivModLNode::make(Compile* C, Node* div_or_mod) {
   Node* n = div_or_mod;
   assert(n->Opcode() == Op_DivL || n->Opcode() == Op_ModL,
          "only div or mod input pattern accepted");
   DivModLNode* divmod = new (C, 3) DivModLNode(n->in(0), n->in(1), n->in(2));
   Node*        dproj  = new (C, 1) ProjNode(divmod, DivModNode::div_proj_num);
   Node*        mproj  = new (C, 1) ProjNode(divmod, DivModNode::mod_proj_num);
   return divmod;
 }
 //------------------------------match------------------------------------------
 // return result(s) along with their RegMask info
 Node *DivModINode::match( const ProjNode *proj, const Matcher *match ) {
   uint ideal_reg = proj->ideal_reg();
   RegMask rm;
   if (proj->_con == div_proj_num) {
     rm = match->divI_proj_mask();
   } else {
     assert(proj->_con == mod_proj_num, "must be div or mod projection");
     rm = match->modI_proj_mask();
   }
   return new (match->C, 1)MachProjNode(this, proj->_con, rm, ideal_reg);
 }
 //------------------------------match------------------------------------------
 // return result(s) along with their RegMask info
 Node *DivModLNode::match( const ProjNode *proj, const Matcher *match ) {
   uint ideal_reg = proj->ideal_reg();
   RegMask rm;
   if (proj->_con == div_proj_num) {
     rm = match->divL_proj_mask();
   } else {
     assert(proj->_con == mod_proj_num, "must be div or mod projection");
     rm = match->modL_proj_mask();
   }
   return new (match->C, 1)MachProjNode(this, proj->_con, rm, ideal_reg);
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/divnode.cpp@a61af66fc99e (annotated)

src/share/vm/opto/divnode.cpp