1 /* 2 ********************************************************************** 3 * Copyright (C) 2002-2003, International Business Machines 4 * Corporation and others. All Rights Reserved. 5 ********************************************************************** 6 */ 7 8 #include "layout/LETypes.h" 9 #include "LXUtilities.h" 10 11 U_NAMESPACE_BEGIN 12 13 // 14 // Finds the high bit by binary searching 15 // through the bits in n. 16 // 17 le_int8 LXUtilities::highBit(le_int32 value) 18 { 19 if (value <= 0) { 20 return -32; 21 } 22 23 le_int8 bit = 0; 24 25 if (value >= 1 << 16) { 26 value >>= 16; 27 bit += 16; 28 } 29 30 if (value >= 1 << 8) { 31 value >>= 8; 32 bit += 8; 33 } 34 35 if (value >= 1 << 4) { 36 value >>= 4; 37 bit += 4; 38 } 39 40 if (value >= 1 << 2) { 41 value >>= 2; 42 bit += 2; 43 } 44 45 if (value >= 1 << 1) { 46 value >>= 1; 47 bit += 1; 48 } 49 50 return bit; 51 } 52 53 le_int32 LXUtilities::search(le_int32 value, const le_int32 array[], le_int32 count) 54 { 55 le_int32 power = 1 << highBit(count); 56 le_int32 extra = count - power; 57 le_int32 probe = power; 58 le_int32 index = 0; 59 60 if (value >= array[extra]) { 61 index = extra; 62 } 63 64 while (probe > (1 << 0)) { 65 probe >>= 1; 66 67 if (value >= array[index + probe]) { 68 index += probe; 69 } 70 } 71 72 return index; 73 } 74 75 void LXUtilities::reverse(le_int32 array[], le_int32 length) 76 { 77 le_int32 front, back; 78 79 for (front = 0, back = length - 1; front < back; front += 1, back -= 1) { 80 le_int32 swap = array[front]; 81 82 array[front] = array[back]; 83 array[back] = swap; 84 } 85 } 86 87 void LXUtilities::reverse(float array[], le_int32 length) 88 { 89 le_int32 front, back; 90 91 for (front = 0, back = length - 1; front < back; front += 1, back -= 1) { 92 float swap = array[front]; 93 94 array[front] = array[back]; 95 array[back] = swap; 96 } 97 } 98 99 U_NAMESPACE_END 100
