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by brian
clean slate |
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/******************************************************************
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Various utilities
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(c) 1994, 1995 Innobase Oy
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Created 5/30/1994 Heikki Tuuri
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*******************************************************************/
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/**********************************************************
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Calculates the minimum of two ulints. */
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UNIV_INLINE |
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ulint |
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ut_min(
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/*===*/
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/* out: minimum */ |
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ulint n1, /* in: first number */ |
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ulint n2) /* in: second number */ |
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{
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return((n1 <= n2) ? n1 : n2); |
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}
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/**********************************************************
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Calculates the maximum of two ulints. */
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UNIV_INLINE |
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ulint |
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ut_max(
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/*===*/
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/* out: maximum */ |
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ulint n1, /* in: first number */ |
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ulint n2) /* in: second number */ |
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{
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return((n1 <= n2) ? n2 : n1); |
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}
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/********************************************************************
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Calculates minimum of two ulint-pairs. */
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UNIV_INLINE |
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void |
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ut_pair_min(
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/*========*/
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ulint* a, /* out: more significant part of minimum */ |
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ulint* b, /* out: less significant part of minimum */ |
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ulint a1, /* in: more significant part of first pair */ |
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ulint b1, /* in: less significant part of first pair */ |
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ulint a2, /* in: more significant part of second pair */ |
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ulint b2) /* in: less significant part of second pair */ |
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{
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if (a1 == a2) { |
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*a = a1; |
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*b = ut_min(b1, b2); |
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} else if (a1 < a2) { |
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*a = a1; |
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*b = b1; |
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} else { |
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*a = a2; |
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*b = b2; |
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} |
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}
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/**********************************************************
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Compares two ulints. */
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UNIV_INLINE |
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int |
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ut_ulint_cmp(
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/*=========*/
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/* out: 1 if a > b, 0 if a == b, -1 if a < b */ |
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ulint a, /* in: ulint */ |
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ulint b) /* in: ulint */ |
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{
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if (a < b) { |
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return(-1); |
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} else if (a == b) { |
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return(0); |
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} else { |
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return(1); |
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} |
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}
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/***********************************************************
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Compares two pairs of ulints. */
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UNIV_INLINE |
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int |
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ut_pair_cmp(
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/*========*/
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/* out: -1 if a < b, 0 if a == b, 1 if a > b */ |
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ulint a1, /* in: more significant part of first pair */ |
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ulint a2, /* in: less significant part of first pair */ |
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ulint b1, /* in: more significant part of second pair */ |
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ulint b2) /* in: less significant part of second pair */ |
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{
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if (a1 > b1) { |
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return(1); |
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} else if (a1 < b1) { |
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return(-1); |
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} else if (a2 > b2) { |
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return(1); |
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} else if (a2 < b2) { |
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return(-1); |
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} else { |
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return(0); |
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} |
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}
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/*****************************************************************
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Calculates fast the remainder when divided by a power of two. */
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UNIV_INLINE |
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ulint |
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ut_2pow_remainder(
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/*==============*/ /* out: remainder */ |
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ulint n, /* in: number to be divided */ |
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ulint m) /* in: divisor; power of 2 */ |
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{
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ut_ad(0x80000000UL % m == 0); |
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return(n & (m - 1)); |
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}
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/*****************************************************************
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Calculates fast a value rounded to a multiple of a power of 2. */
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UNIV_INLINE |
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ulint |
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ut_2pow_round(
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/*==========*/ /* out: value of n rounded down to nearest |
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multiple of m */
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ulint n, /* in: number to be rounded */ |
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ulint m) /* in: divisor; power of 2 */ |
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{
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ut_ad(0x80000000UL % m == 0); |
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return(n & ~(m - 1)); |
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}
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/*****************************************************************
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Calculates fast the 2-logarithm of a number, rounded upward to an
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integer. */
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UNIV_INLINE |
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ulint |
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ut_2_log(
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/*=====*/
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/* out: logarithm in the base 2, rounded upward */ |
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ulint n) /* in: number != 0 */ |
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{
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ulint res; |
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res = 0; |
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ut_ad(n > 0); |
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n = n - 1; |
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for (;;) { |
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n = n / 2; |
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if (n == 0) { |
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break; |
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} |
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res++; |
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} |
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return(res + 1); |
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}
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/*****************************************************************
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Calculates 2 to power n. */
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UNIV_INLINE |
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ulint |
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ut_2_exp(
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/*=====*/
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/* out: 2 to power n */ |
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ulint n) /* in: number */ |
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{
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return((ulint) 1 << n); |
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}
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