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//
// bitops.h
//
// Bitmap manipulation routines
//
// Copyright (C) 2002 Michael Ringgaard. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. 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.
// 3. Neither the name of the project 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 BITOPS_H
#define BITOPS_H
#ifdef __cplusplus
extern "C" {
#endif
__inline void set_bit(void *bitmap, int pos) {
__asm {
mov eax, pos
mov ebx, bitmap
bts dword ptr [ebx], eax
}
}
__inline void clear_bit(void *bitmap, int pos) {
__asm {
mov eax, pos
mov ebx, bitmap
btr dword ptr [ebx], eax
}
}
__inline int test_bit(void *bitmap, int pos) {
int result;
__asm {
mov eax, pos
mov ebx, bitmap
bt dword ptr [ebx], eax
sbb eax, eax
mov result, eax
}
return result;
}
static __inline int find_lowest_bit(unsigned mask) {
int n;
__asm {
bsf eax, mask
mov n, eax
}
return n;
}
#if 0
static __inline int find_highest_bit(unsigned mask) {
int n;
__asm {
bsr eax, mask
mov n, eax
}
return n;
}
#else
static __inline int find_highest_bit(unsigned mask) {
int n = 31;
while (n > 0 && !(mask & 0x80000000)) {
mask <<= 1;
n--;
}
return n;
}
#endif
__inline void set_bits(void *bitmap, int pos, int len) {
while (len-- > 0) set_bit(bitmap, pos++);
}
int find_first_zero_bit(void *bitmap, int len);
int find_next_zero_bit(void *bitmap, int len, int start);
#ifdef __cplusplus
}
#endif
#endif