diff options
Diffstat (limited to 'src/base/intmath.hh')
| -rw-r--r-- | src/base/intmath.hh | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/src/base/intmath.hh b/src/base/intmath.hh new file mode 100644 index 000000000..51baddb91 --- /dev/null +++ b/src/base/intmath.hh @@ -0,0 +1,230 @@ +/* + * Copyright (c) 2001, 2003-2005 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef __INTMATH_HH__ +#define __INTMATH_HH__ + +#include <assert.h> + +#include "sim/host.hh" + +// Returns the prime number one less than n. +int prevPrime(int n); + +// Determine if a number is prime +template <class T> +inline bool +isPrime(T n) +{ + T i; + + if (n == 2 || n == 3) + return true; + + // Don't try every odd number to prove if it is a prime. + // Toggle between every 2nd and 4th number. + // (This is because every 6th odd number is divisible by 3.) + for (i = 5; i*i <= n; i += 6) { + if (((n % i) == 0 ) || ((n % (i + 2)) == 0) ) { + return false; + } + } + + return true; +} + +template <class T> +inline T +leastSigBit(T n) +{ + return n & ~(n - 1); +} + +template <class T> +inline bool +isPowerOf2(T n) +{ + return n != 0 && leastSigBit(n) == n; +} + +inline int +floorLog2(unsigned x) +{ + assert(x > 0); + + int y = 0; + + if (x & 0xffff0000) { y += 16; x >>= 16; } + if (x & 0x0000ff00) { y += 8; x >>= 8; } + if (x & 0x000000f0) { y += 4; x >>= 4; } + if (x & 0x0000000c) { y += 2; x >>= 2; } + if (x & 0x00000002) { y += 1; } + + return y; +} + +inline int +floorLog2(unsigned long x) +{ + assert(x > 0); + + int y = 0; + +#if defined(__LP64__) + if (x & ULL(0xffffffff00000000)) { y += 32; x >>= 32; } +#endif + if (x & 0xffff0000) { y += 16; x >>= 16; } + if (x & 0x0000ff00) { y += 8; x >>= 8; } + if (x & 0x000000f0) { y += 4; x >>= 4; } + if (x & 0x0000000c) { y += 2; x >>= 2; } + if (x & 0x00000002) { y += 1; } + + return y; +} + +inline int +floorLog2(unsigned long long x) +{ + assert(x > 0); + + int y = 0; + + if (x & ULL(0xffffffff00000000)) { y += 32; x >>= 32; } + if (x & ULL(0x00000000ffff0000)) { y += 16; x >>= 16; } + if (x & ULL(0x000000000000ff00)) { y += 8; x >>= 8; } + if (x & ULL(0x00000000000000f0)) { y += 4; x >>= 4; } + if (x & ULL(0x000000000000000c)) { y += 2; x >>= 2; } + if (x & ULL(0x0000000000000002)) { y += 1; } + + return y; +} + +inline int +floorLog2(int x) +{ + assert(x > 0); + return floorLog2((unsigned)x); +} + +inline int +floorLog2(long x) +{ + assert(x > 0); + return floorLog2((unsigned long)x); +} + +inline int +floorLog2(long long x) +{ + assert(x > 0); + return floorLog2((unsigned long long)x); +} + +template <class T> +inline int +ceilLog2(T n) +{ + if (n == 1) + return 0; + + return floorLog2(n - (T)1) + 1; +} + +template <class T> +inline T +floorPow2(T n) +{ + return (T)1 << floorLog2(n); +} + +template <class T> +inline T +ceilPow2(T n) +{ + return (T)1 << ceilLog2(n); +} + +template <class T> +inline T +divCeil(T a, T b) +{ + return (a + b - 1) / b; +} + +template <class T> +inline T +roundUp(T val, int align) +{ + T mask = (T)align - 1; + return (val + mask) & ~mask; +} + +template <class T> +inline T +roundDown(T val, int align) +{ + T mask = (T)align - 1; + return val & ~mask; +} + +inline bool +isHex(char c) +{ + return c >= '0' && c <= '9' || + c >= 'A' && c <= 'F' || + c >= 'a' && c <= 'f'; +} + +inline bool +isOct(char c) +{ + return c >= '0' && c <= '7'; +} + +inline bool +isDec(char c) +{ + return c >= '0' && c <= '9'; +} + +inline int +hex2Int(char c) +{ + if (c >= '0' && c <= '9') + return (c - '0'); + + if (c >= 'A' && c <= 'F') + return (c - 'A') + 10; + + if (c >= 'a' && c <= 'f') + return (c - 'a') + 10; + + return 0; +} + +#endif // __INTMATH_HH__ |