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/*
SuperCollider real time audio synthesis system
Copyright (c) 2002 James McCartney. All rights reserved.
http://www.audiosynth.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
count leading zeroes function and those that can be derived from it
*/
#ifndef _CLZ_
#define _CLZ_
#include "SC_Types.h"
#ifdef __MWERKS__
#define __PPC__ 1
#define __X86__ 0
// powerpc native count leading zeroes instruction:
#define CLZ(x) ((int)__cntlzw((unsigned int)x))
#elif defined(SC_WIN32) && !defined(__GCC__)
static int32 CLZ( int32 arg )
{
__asm{
bsr eax, arg
jnz non_zero
mov arg, 32
jmp end
non_zero:
xor eax, 31
mov arg, eax
end:
}
return arg;
}
#elif defined(__ppc__) || defined(__powerpc__) || defined(__PPC__)
static __inline__ int32 CLZ(int32 arg) {
__asm__ volatile("cntlzw %0, %1" : "=r" (arg) : "r" (arg));
return arg;
}
#elif defined(__i386__) || defined(__x86_64__)
static __inline__ int32 CLZ(int32 arg) {
if (arg) {
__asm__ volatile("bsrl %0, %0\nxorl $31, %0\n"
: "=r" (arg) : "0" (arg));
} else {
arg = 32;
}
return arg;
}
#else
# error "clz.h: Unsupported architecture"
#endif
// count trailing zeroes
inline int32 CTZ(int32 x)
{
return 32 - CLZ(~x & (x-1));
}
// count leading ones
inline int32 CLO(int32 x)
{
return CLZ(~x);
}
// count trailing ones
inline int32 CTO(int32 x)
{
return 32 - CLZ(x & (~x-1));
}
// number of bits required to represent x.
inline int32 NUMBITS(int32 x)
{
return 32 - CLZ(x);
}
// log2 of the next power of two greater than or equal to x.
inline int32 LOG2CEIL(int32 x)
{
return 32 - CLZ(x - 1);
}
// next power of two greater than or equal to x
inline int32 NEXTPOWEROFTWO(int32 x)
{
return 1L << LOG2CEIL(x);
}
// is x a power of two
inline bool ISPOWEROFTWO(int32 x)
{
return (x & (x-1)) == 0;
}
// input a series of counting integers, outputs a series of gray codes .
inline int32 GRAYCODE(int32 x)
{
return x & (x>>1);
}
// find least significant bit
inline int32 LSBit(int32 x)
{
return x & -x;
}
// find least significant bit position
inline int32 LSBitPos(int32 x)
{
return CTZ(x & -x);
}
// find most significant bit position
inline int32 MSBitPos(int32 x)
{
return 31 - CLZ(x);
}
// find most significant bit
inline int32 MSBit(int32 x)
{
return 1L << MSBitPos(x);
}
// count number of one bits
inline uint32 ONES(uint32 x)
{
uint32 t;
x = x - ((x >> 1) & 0x55555555);
t = ((x >> 2) & 0x33333333);
x = (x & 0x33333333) + t;
x = (x + (x >> 4)) & 0x0F0F0F0F;
x = x + (x << 8);
x = x + (x << 16);
return x >> 24;
}
// count number of zero bits
inline uint32 ZEROES(uint32 x)
{
return ONES(~x);
}
// reverse bits in a word
inline uint32 BitReverse(uint32 x)
{
x = ((x & 0xAAAAAAAA) >> 1) | ((x & 0x55555555) << 1);
x = ((x & 0xCCCCCCCC) >> 2) | ((x & 0x33333333) << 2);
x = ((x & 0xF0F0F0F0) >> 4) | ((x & 0x0F0F0F0F) << 4);
x = ((x & 0xFF00FF00) >> 8) | ((x & 0x00FF00FF) << 8);
return (x >> 16) | (x << 16);
}
// barrel shifts
inline uint32 RotateRight (uint32 x, uint32 s)
{
s = s & 31;
return (x << (32-s)) | (x >> s);
}
inline uint32 RotateLeft (uint32 x, uint32 s)
{
s = s & 31;
return (x >> (32-s)) | (x << s);
}
#endif
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