53 lines
1.3 KiB
C
53 lines
1.3 KiB
C
/****************************************************************
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* *
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* Copyright 2001 Sanchez Computer Associates, Inc. *
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* *
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* This source code contains the intellectual property *
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* of its copyright holder(s), and is made available *
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* under a license. If you do not know the terms of *
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* the license, please stop and do not read further. *
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* *
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****************************************************************/
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#include "mdef.h"
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#include "gtm_ffs.h"
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#define BITS_PER_UCHAR 8
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int gtm_ffs (uint4 offset, uchar_ptr_t addr, uint4 size)
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{
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uchar_ptr_t c;
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int i, j, top;
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c = addr + (offset / BITS_PER_UCHAR);
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if (i = (offset & (BITS_PER_UCHAR - 1)))
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{ /* partial byte starting at offset */
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for (j = 0; (i < BITS_PER_UCHAR) && (j < size); j++, i++)
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{
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if (*c & (1 << i))
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return (offset + j);
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}
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c++;
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}
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assert(c == (addr + (offset + BITS_PER_UCHAR - 1) / BITS_PER_UCHAR));
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for (i = ROUND_UP2(offset, BITS_PER_UCHAR), top = ROUND_DOWN2(size + offset, BITS_PER_UCHAR); i < top;
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c++, i += BITS_PER_UCHAR)
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{ /* full bytes offset to end */
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if (*c)
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{
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for (j = 0; j < BITS_PER_UCHAR; j++)
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{
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if (*c & (1 << j))
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return (i + j);
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}
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}
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}
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for (j = 0, top = size + offset; i < top; j++, i++)
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{ /* partial byte at end */
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assert(j < BITS_PER_UCHAR);
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if (*c & (1 << j))
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return i;
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}
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return -1;
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}
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