1 /*
   2  * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.marlin;
  27 
  28 /**
  29  * Faster Math ceil / floor routines derived from StrictMath
  30  */
  31 public final class FloatMath implements MarlinConst {
  32 
  33     // overflow / NaN handling enabled:
  34     static final boolean CHECK_OVERFLOW = true;
  35     static final boolean CHECK_NAN = true;
  36 
  37     private FloatMath() {
  38         // utility class
  39     }
  40 
  41     // faster inlined min/max functions in the branch prediction is high
  42     public static int max(final int a, final int b) {
  43         return (a >= b) ? a : b;
  44     }
  45 
  46     public static int min(final int a, final int b) {
  47         return (a <= b) ? a : b;
  48     }
  49 
  50     /**
  51      * Faster alternative to ceil(float) optimized for the integer domain
  52      * and supporting NaN and +/-Infinity.
  53      *
  54      * @param a a value.
  55      * @return the largest (closest to positive infinity) integer value
  56      * that less than or equal to the argument and is equal to a mathematical
  57      * integer.
  58      */
  59     public static int ceil_int(final float a) {
  60         final int intpart = (int) a;
  61 
  62         if (a <= intpart
  63                 || (CHECK_OVERFLOW && intpart == Integer.MAX_VALUE)
  64                 || CHECK_NAN && Float.isNaN(a)) {
  65             return intpart;
  66         }
  67         return intpart + 1;
  68     }
  69 
  70     /**
  71      * Faster alternative to ceil(double) optimized for the integer domain
  72      * and supporting NaN and +/-Infinity.
  73      *
  74      * @param a a value.
  75      * @return the largest (closest to positive infinity) integer value
  76      * that less than or equal to the argument and is equal to a mathematical
  77      * integer.
  78      */
  79     public static int ceil_int(final double a) {
  80         final int intpart = (int) a;
  81 
  82         if (a <= intpart
  83                 || (CHECK_OVERFLOW && intpart == Integer.MAX_VALUE)
  84                 || CHECK_NAN && Double.isNaN(a)) {
  85             return intpart;
  86         }
  87         return intpart + 1;
  88     }
  89 
  90     /**
  91      * Faster alternative to floor(float) optimized for the integer domain
  92      * and supporting NaN and +/-Infinity.
  93      *
  94      * @param a a value.
  95      * @return the largest (closest to positive infinity) floating-point value
  96      * that less than or equal to the argument and is equal to a mathematical
  97      * integer.
  98      */
  99     public static int floor_int(final float a) {
 100         final int intpart = (int) a;
 101 
 102         if (a >= intpart
 103                 || (CHECK_OVERFLOW && intpart == Integer.MIN_VALUE)
 104                 || CHECK_NAN && Float.isNaN(a)) {
 105             return intpart;
 106         }
 107         return intpart - 1;
 108     }
 109 
 110     /**
 111      * Faster alternative to floor(double) optimized for the integer domain
 112      * and supporting NaN and +/-Infinity.
 113      *
 114      * @param a a value.
 115      * @return the largest (closest to positive infinity) floating-point value
 116      * that less than or equal to the argument and is equal to a mathematical
 117      * integer.
 118      */
 119     public static int floor_int(final double a) {
 120         final int intpart = (int) a;
 121 
 122         if (a >= intpart
 123                 || (CHECK_OVERFLOW && intpart == Integer.MIN_VALUE)
 124                 || CHECK_NAN && Double.isNaN(a)) {
 125             return intpart;
 126         }
 127         return intpart - 1;
 128     }
 129 }