intmath.hh revision 2020
1/* 2 * Copyright (c) 2001, 2003-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#ifndef __INTMATH_HH__ 30#define __INTMATH_HH__ 31 32#include <assert.h> 33 34#include "sim/host.hh" 35 36// Returns the prime number one less than n. 37int prevPrime(int n); 38 39// Determine if a number is prime 40template <class T> 41inline bool 42isPrime(T n) 43{ 44 T i; 45 46 if (n == 2 || n == 3) 47 return true; 48 49 // Don't try every odd number to prove if it is a prime. 50 // Toggle between every 2nd and 4th number. 51 // (This is because every 6th odd number is divisible by 3.) 52 for (i = 5; i*i <= n; i += 6) { 53 if (((n % i) == 0 ) || ((n % (i + 2)) == 0) ) { 54 return false; 55 } 56 } 57 58 return true; 59} 60 61template <class T> 62inline T 63leastSigBit(T n) 64{ 65 return n & ~(n - 1); 66} 67 68template <class T> 69inline bool 70isPowerOf2(T n) 71{ 72 return n != 0 && leastSigBit(n) == n; 73} 74 75inline int 76floorLog2(unsigned x) 77{ 78 assert(x > 0); 79 80 int y = 0; 81 82 if (x & 0xffff0000) { y += 16; x >>= 16; } 83 if (x & 0x0000ff00) { y += 8; x >>= 8; } 84 if (x & 0x000000f0) { y += 4; x >>= 4; } 85 if (x & 0x0000000c) { y += 2; x >>= 2; } 86 if (x & 0x00000002) { y += 1; } 87 88 return y; 89} 90 91inline int 92floorLog2(unsigned long x) 93{ 94 assert(x > 0); 95 96 int y = 0; 97 98#if defined(__LP64__) 99 if (x & ULL(0xffffffff00000000)) { y += 32; x >>= 32; } 100#endif 101 if (x & 0xffff0000) { y += 16; x >>= 16; } 102 if (x & 0x0000ff00) { y += 8; x >>= 8; } 103 if (x & 0x000000f0) { y += 4; x >>= 4; } 104 if (x & 0x0000000c) { y += 2; x >>= 2; } 105 if (x & 0x00000002) { y += 1; } 106 107 return y; 108} 109 110inline int 111floorLog2(unsigned long long x) 112{ 113 assert(x > 0); 114 115 int y = 0; 116 117 if (x & ULL(0xffffffff00000000)) { y += 32; x >>= 32; } 118 if (x & ULL(0x00000000ffff0000)) { y += 16; x >>= 16; } 119 if (x & ULL(0x000000000000ff00)) { y += 8; x >>= 8; } 120 if (x & ULL(0x00000000000000f0)) { y += 4; x >>= 4; } 121 if (x & ULL(0x000000000000000c)) { y += 2; x >>= 2; } 122 if (x & ULL(0x0000000000000002)) { y += 1; } 123 124 return y; 125} 126 127inline int 128floorLog2(int x) 129{ 130 assert(x > 0); 131 return floorLog2((unsigned)x); 132} 133 134inline int 135floorLog2(long x) 136{ 137 assert(x > 0); 138 return floorLog2((unsigned long)x); 139} 140 141inline int 142floorLog2(long long x) 143{ 144 assert(x > 0); 145 return floorLog2((unsigned long long)x); 146} 147 148#if defined(__APPLE__) 149inline int 150floorLog2(size_t x) 151{ 152 assert(x > 0); 153 assert(sizeof(size_t) == 4 || sizeof(size_t) == 8); 154 155 // It's my hope that this is optimized away? 156 if (sizeof(size_t) == 4) 157 return floorLog2((uint32_t)x); 158 else if (sizeof(size_t) == 8) 159 return floorLog2((uint64_t)x); 160 161} 162#endif 163 164template <class T> 165inline int 166ceilLog2(T n) 167{ 168 if (n == 1) 169 return 0; 170 171 return floorLog2(n - (T)1) + 1; 172} 173 174template <class T> 175inline T 176floorPow2(T n) 177{ 178 return (T)1 << floorLog2(n); 179} 180 181template <class T> 182inline T 183ceilPow2(T n) 184{ 185 return (T)1 << ceilLog2(n); 186} 187 188template <class T> 189inline T 190divCeil(T a, T b) 191{ 192 return (a + b - 1) / b; 193} 194 195template <class T> 196inline T 197roundUp(T val, T align) 198{ 199 T mask = align - 1; 200 return (val + mask) & ~mask; 201} 202 203template <class T> 204inline T 205roundDown(T val, T align) 206{ 207 T mask = align - 1; 208 return val & ~mask; 209} 210 211inline bool 212isHex(char c) 213{ 214 return c >= '0' && c <= '9' || 215 c >= 'A' && c <= 'F' || 216 c >= 'a' && c <= 'f'; 217} 218 219inline bool 220isOct(char c) 221{ 222 return c >= '0' && c <= '7'; 223} 224 225inline bool 226isDec(char c) 227{ 228 return c >= '0' && c <= '9'; 229} 230 231inline int 232hex2Int(char c) 233{ 234 if (c >= '0' && c <= '9') 235 return (c - '0'); 236 237 if (c >= 'A' && c <= 'F') 238 return (c - 'A') + 10; 239 240 if (c >= 'a' && c <= 'f') 241 return (c - 'a') + 10; 242 243 return 0; 244} 245 246#endif // __INTMATH_HH__ 247