jdk8-mips64-public/langtools: src/share/classes/com/sun/tools/javac/comp/ConstFold.java@af8417e590f4 (annotated)

src/share/classes/com/sun/tools/javac/comp/ConstFold.java@af8417e590f4 (annotated)

src/share/classes/com/sun/tools/javac/comp/ConstFold.java

Sun, 17 Feb 2013 16:44:55 -0500

author: dholmes
date: Sun, 17 Feb 2013 16:44:55 -0500
changeset 1571: af8417e590f4
parent 1521: 71f35e4b93a5
child 2525: 2eb010b6cb22
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 1999, 2013, Oracle and/or its affiliates. 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.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package com.sun.tools.javac.comp;
 import com.sun.tools.javac.code.*;
 import com.sun.tools.javac.jvm.*;
 import com.sun.tools.javac.util.*;
 import static com.sun.tools.javac.code.TypeTag.BOOLEAN;
 import static com.sun.tools.javac.jvm.ByteCodes.*;
 /** Helper class for constant folding, used by the attribution phase.
  *  This class is marked strictfp as mandated by JLS 15.4.
  *
  *  <p><b>This is NOT part of any supported API.
  *  If you write code that depends on this, you do so at your own risk.
  *  This code and its internal interfaces are subject to change or
  *  deletion without notice.</b>
  */
 strictfp class ConstFold {
     protected static final Context.Key<ConstFold> constFoldKey =
         new Context.Key<ConstFold>();
     private Symtab syms;
     public static ConstFold instance(Context context) {
         ConstFold instance = context.get(constFoldKey);
         if (instance == null)
             instance = new ConstFold(context);
         return instance;
     }
     private ConstFold(Context context) {
         context.put(constFoldKey, this);
         syms = Symtab.instance(context);
     }
     static final Integer minusOne = -1;
     static final Integer zero     = 0;
     static final Integer one      = 1;
    /** Convert boolean to integer (true = 1, false = 0).
     */
     private static Integer b2i(boolean b) {
         return b ? one : zero;
     }
     private static int intValue(Object x) { return ((Number)x).intValue(); }
     private static long longValue(Object x) { return ((Number)x).longValue(); }
     private static float floatValue(Object x) { return ((Number)x).floatValue(); }
     private static double doubleValue(Object x) { return ((Number)x).doubleValue(); }
     /** Fold binary or unary operation, returning constant type reflecting the
      *  operations result. Return null if fold failed due to an
      *  arithmetic exception.
      *  @param opcode    The operation's opcode instruction (usually a byte code),
      *                   as entered by class Symtab.
      *  @param argtypes  The operation's argument types (a list of length 1 or 2).
      *                   Argument types are assumed to have non-null constValue's.
      */
     Type fold(int opcode, List<Type> argtypes) {
         int argCount = argtypes.length();
         if (argCount == 1)
             return fold1(opcode, argtypes.head);
         else if (argCount == 2)
             return fold2(opcode, argtypes.head, argtypes.tail.head);
         else
             throw new AssertionError();
     }
     /** Fold unary operation.
      *  @param opcode    The operation's opcode instruction (usually a byte code),
      *                   as entered by class Symtab.
      *                   opcode's ifeq to ifge are for postprocessing
      *                   xcmp; ifxx pairs of instructions.
      *  @param operand   The operation's operand type.
      *                   Argument types are assumed to have non-null constValue's.
      */
     Type fold1(int opcode, Type operand) {
         try {
             Object od = operand.constValue();
             switch (opcode) {
             case nop:
                 return operand;
             case ineg: // unary -
                 return syms.intType.constType(-intValue(od));
             case ixor: // ~
                 return syms.intType.constType(~intValue(od));
             case bool_not: // !
                 return syms.booleanType.constType(b2i(intValue(od) == 0));
             case ifeq:
                 return syms.booleanType.constType(b2i(intValue(od) == 0));
             case ifne:
                 return syms.booleanType.constType(b2i(intValue(od) != 0));
             case iflt:
                 return syms.booleanType.constType(b2i(intValue(od) < 0));
             case ifgt:
                 return syms.booleanType.constType(b2i(intValue(od) > 0));
             case ifle:
                 return syms.booleanType.constType(b2i(intValue(od) <= 0));
             case ifge:
                 return syms.booleanType.constType(b2i(intValue(od) >= 0));
             case lneg: // unary -
                 return syms.longType.constType(new Long(-longValue(od)));
             case lxor: // ~
                 return syms.longType.constType(new Long(~longValue(od)));
             case fneg: // unary -
                 return syms.floatType.constType(new Float(-floatValue(od)));
             case dneg: // ~
                 return syms.doubleType.constType(new Double(-doubleValue(od)));
             default:
                 return null;
             }
         } catch (ArithmeticException e) {
             return null;
         }
     }
     /** Fold binary operation.
      *  @param opcode    The operation's opcode instruction (usually a byte code),
      *                   as entered by class Symtab.
      *                   opcode's ifeq to ifge are for postprocessing
      *                   xcmp; ifxx pairs of instructions.
      *  @param left      The type of the operation's left operand.
      *  @param right     The type of the operation's right operand.
      */
     Type fold2(int opcode, Type left, Type right) {
         try {
             if (opcode > ByteCodes.preMask) {
                 // we are seeing a composite instruction of the form xcmp; ifxx.
                 // In this case fold both instructions separately.
                 Type t1 = fold2(opcode >> ByteCodes.preShift, left, right);
                 return (t1.constValue() == null) ? t1
                     : fold1(opcode & ByteCodes.preMask, t1);
             } else {
                 Object l = left.constValue();
                 Object r = right.constValue();
                 switch (opcode) {
                 case iadd:
                     return syms.intType.constType(intValue(l) + intValue(r));
                 case isub:
                     return syms.intType.constType(intValue(l) - intValue(r));
                 case imul:
                     return syms.intType.constType(intValue(l) * intValue(r));
                 case idiv:
                     return syms.intType.constType(intValue(l) / intValue(r));
                 case imod:
                     return syms.intType.constType(intValue(l) % intValue(r));
                 case iand:
                     return (left.hasTag(BOOLEAN)
                       ? syms.booleanType : syms.intType)
                       .constType(intValue(l) & intValue(r));
                 case bool_and:
                     return syms.booleanType.constType(b2i((intValue(l) & intValue(r)) != 0));
                 case ior:
                     return (left.hasTag(BOOLEAN)
                       ? syms.booleanType : syms.intType)
                       .constType(intValue(l) | intValue(r));
                 case bool_or:
                     return syms.booleanType.constType(b2i((intValue(l) | intValue(r)) != 0));
                 case ixor:
                     return (left.hasTag(BOOLEAN)
                       ? syms.booleanType : syms.intType)
                       .constType(intValue(l) ^ intValue(r));
                 case ishl: case ishll:
                     return syms.intType.constType(intValue(l) << intValue(r));
                 case ishr: case ishrl:
                     return syms.intType.constType(intValue(l) >> intValue(r));
                 case iushr: case iushrl:
                     return syms.intType.constType(intValue(l) >>> intValue(r));
                 case if_icmpeq:
                     return syms.booleanType.constType(
                         b2i(intValue(l) == intValue(r)));
                 case if_icmpne:
                     return syms.booleanType.constType(
                         b2i(intValue(l) != intValue(r)));
                 case if_icmplt:
                     return syms.booleanType.constType(
                         b2i(intValue(l) < intValue(r)));
                 case if_icmpgt:
                     return syms.booleanType.constType(
                         b2i(intValue(l) > intValue(r)));
                 case if_icmple:
                     return syms.booleanType.constType(
                         b2i(intValue(l) <= intValue(r)));
                 case if_icmpge:
                     return syms.booleanType.constType(
                         b2i(intValue(l) >= intValue(r)));
                 case ladd:
                     return syms.longType.constType(
                         new Long(longValue(l) + longValue(r)));
                 case lsub:
                     return syms.longType.constType(
                         new Long(longValue(l) - longValue(r)));
                 case lmul:
                     return syms.longType.constType(
                         new Long(longValue(l) * longValue(r)));
                 case ldiv:
                     return syms.longType.constType(
                         new Long(longValue(l) / longValue(r)));
                 case lmod:
                     return syms.longType.constType(
                         new Long(longValue(l) % longValue(r)));
                 case land:
                     return syms.longType.constType(
                         new Long(longValue(l) & longValue(r)));
                 case lor:
                     return syms.longType.constType(
                         new Long(longValue(l) | longValue(r)));
                 case lxor:
                     return syms.longType.constType(
                         new Long(longValue(l) ^ longValue(r)));
                 case lshl: case lshll:
                     return syms.longType.constType(
                         new Long(longValue(l) << intValue(r)));
                 case lshr: case lshrl:
                     return syms.longType.constType(
                         new Long(longValue(l) >> intValue(r)));
                 case lushr:
                     return syms.longType.constType(
                         new Long(longValue(l) >>> intValue(r)));
                 case lcmp:
                     if (longValue(l) < longValue(r))
                         return syms.intType.constType(minusOne);
                     else if (longValue(l) > longValue(r))
                         return syms.intType.constType(one);
                     else
                         return syms.intType.constType(zero);
                 case fadd:
                     return syms.floatType.constType(
                         new Float(floatValue(l) + floatValue(r)));
                 case fsub:
                     return syms.floatType.constType(
                         new Float(floatValue(l) - floatValue(r)));
                 case fmul:
                     return syms.floatType.constType(
                         new Float(floatValue(l) * floatValue(r)));
                 case fdiv:
                     return syms.floatType.constType(
                         new Float(floatValue(l) / floatValue(r)));
                 case fmod:
                     return syms.floatType.constType(
                         new Float(floatValue(l) % floatValue(r)));
                 case fcmpg: case fcmpl:
                     if (floatValue(l) < floatValue(r))
                         return syms.intType.constType(minusOne);
                     else if (floatValue(l) > floatValue(r))
                         return syms.intType.constType(one);
                     else if (floatValue(l) == floatValue(r))
                         return syms.intType.constType(zero);
                     else if (opcode == fcmpg)
                         return syms.intType.constType(one);
                     else
                         return syms.intType.constType(minusOne);
                 case dadd:
                     return syms.doubleType.constType(
                         new Double(doubleValue(l) + doubleValue(r)));
                 case dsub:
                     return syms.doubleType.constType(
                         new Double(doubleValue(l) - doubleValue(r)));
                 case dmul:
                     return syms.doubleType.constType(
                         new Double(doubleValue(l) * doubleValue(r)));
                 case ddiv:
                     return syms.doubleType.constType(
                         new Double(doubleValue(l) / doubleValue(r)));
                 case dmod:
                     return syms.doubleType.constType(
                         new Double(doubleValue(l) % doubleValue(r)));
                 case dcmpg: case dcmpl:
                     if (doubleValue(l) < doubleValue(r))
                         return syms.intType.constType(minusOne);
                     else if (doubleValue(l) > doubleValue(r))
                         return syms.intType.constType(one);
                     else if (doubleValue(l) == doubleValue(r))
                         return syms.intType.constType(zero);
                     else if (opcode == dcmpg)
                         return syms.intType.constType(one);
                     else
                         return syms.intType.constType(minusOne);
                 case if_acmpeq:
                     return syms.booleanType.constType(b2i(l.equals(r)));
                 case if_acmpne:
                     return syms.booleanType.constType(b2i(!l.equals(r)));
                 case string_add:
                     return syms.stringType.constType(
                         left.stringValue() + right.stringValue());
                 default:
                     return null;
                 }
             }
         } catch (ArithmeticException e) {
             return null;
         }
     }
     /** Coerce constant type to target type.
      *  @param etype      The source type of the coercion,
      *                    which is assumed to be a constant type compatible with
      *                    ttype.
      *  @param ttype      The target type of the coercion.
      */
      Type coerce(Type etype, Type ttype) {
          // WAS if (etype.baseType() == ttype.baseType())
          if (etype.tsym.type == ttype.tsym.type)
              return etype;
          if (etype.isNumeric()) {
              Object n = etype.constValue();
              switch (ttype.getTag()) {
              case BYTE:
                  return syms.byteType.constType(0 + (byte)intValue(n));
              case CHAR:
                  return syms.charType.constType(0 + (char)intValue(n));
              case SHORT:
                  return syms.shortType.constType(0 + (short)intValue(n));
              case INT:
                  return syms.intType.constType(intValue(n));
              case LONG:
                  return syms.longType.constType(longValue(n));
              case FLOAT:
                  return syms.floatType.constType(floatValue(n));
              case DOUBLE:
                  return syms.doubleType.constType(doubleValue(n));
              }
          }
          return ttype;
      }
 }

Mercurial > jdk8-mips64-public > langtools / annotate

src/share/classes/com/sun/tools/javac/comp/ConstFold.java@af8417e590f4 (annotated)

src/share/classes/com/sun/tools/javac/comp/ConstFold.java