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41 lines
843 B
C
41 lines
843 B
C
// Copyright 2019-2020, Collabora, Ltd.
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// SPDX-License-Identifier: BSL-1.0
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/*!
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* @file
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* @brief Functions for manipulating tightly packed data as bits.
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* @author Jakob Bornecrantz <jakob@collabora.com>
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* @author Pete Black <pete.black@collabora.com>
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* @ingroup aux_util
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*/
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#include "util/u_bitwise.h"
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#include <stdio.h>
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#include <limits.h>
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int
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get_bit(const unsigned char *b, int num)
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{
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int index = num / CHAR_BIT;
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return (b[index] >> ((CHAR_BIT - 1) - (num % CHAR_BIT))) & 1;
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}
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int
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get_bits(const unsigned char *b, int start, int num)
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{
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int ret = 0;
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for (int i = 0; i < num; i++) {
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ret <<= 1;
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ret |= get_bit(b, start + i);
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}
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return ret;
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}
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int
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sign_extend_13(uint32_t i)
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{
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#define INCOMING_INT_WIDTH (13)
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#define ADJUSTMENT ((sizeof(i) * CHAR_BIT) - INCOMING_INT_WIDTH)
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return ((int)(i << ADJUSTMENT)) >> ADJUSTMENT;
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}
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