生成32位、64位和128位的交织位模式(morton密钥）
Produce interleaving bit patterns (morton keys) for 32 bit , 64 bit and 128bit
我想用最佳代码为32位、64位和128位生成一个morton密钥！解决方案是什么？
以下是我的python脚本解决方案：
我从他的评论中得到了暗示：Fabian"ryg"Giesen
阅读下面的长评论！我们需要跟踪哪些部分需要走多远
然后在每一步中，我们选择这些位并移动它们，并应用位掩码（见最后一行的注释）来掩码它们！
10位数字和2个交错位（32位）的python脚本的位掩码生成器输出（见下文）：
Bit Distances: [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]
Shifting bits by 1 for bits idx: []
Shifting bits by 2 for bits idx: [1, 3, 5, 7, 9]
Shifting bits by 4 for bits idx: [2, 3, 6, 7]
Shifting bits by 8 for bits idx: [4, 5, 6, 7]
Shifting bits by 16 for bits idx: [8, 9]
BitPositions: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Current Mask: 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 1111 1111
Which bits to shift: 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 0000 0000 hex: 0x300
Shifted part (<< 16): 0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 0000 0000 0000 0000 0000 0000 hex: 0x3000000
NonShifted Part: 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1111 1111 hex: 0xff
Bitmask is now : 0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 0000 0000 0000 0000 1111 1111 hex: 0x30000ff
(this is : bitMask = shifted | nonshifted)
Current Mask: 0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 0000 0000 0000 0000 1111 1111
Which bits to shift: 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1111 0000 hex: 0xf0
Shifted part (<< 8): 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1111 0000 0000 0000 hex: 0xf000
NonShifted Part: 0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 0000 0000 0000 0000 0000 1111 hex: 0x300000f
Bitmask is now : 0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 0000 0000 1111 0000 0000 1111 hex: 0x300f00f
(this is : bitMask = shifted | nonshifted)
Current Mask: 0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 0000 0000 1111 0000 0000 1111
Which bits to shift: 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1100 0000 0000 1100 hex: 0xc00c
Shifted part (<< 4): 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1100 0000 0000 1100 0000 hex: 0xc00c0
NonShifted Part: 0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 0000 0000 0011 0000 0000 0011 hex: 0x3003003
Bitmask is now : 0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 0000 1100 0011 0000 1100 0011 hex: 0x30c30c3
(this is : bitMask = shifted | nonshifted)
Current Mask: 0000 0000 0000 0000 0000 0000 0000 0000 0000 0011 0000 1100 0011 0000 1100 0011
Which bits to shift: 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 0000 1000 0010 0000 1000 0010 hex: 0x2082082
Shifted part (<< 2): 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000 0010 0000 1000 0010 0000 1000 hex: 0x8208208
NonShifted Part: 0000 0000 0000 0000 0000 0000 0000 0000 0000 0001 0000 0100 0001 0000 0100 0001 hex: 0x1041041
Bitmask is now : 0000 0000 0000 0000 0000 0000 0000 0000 0000 1001 0010 0100 1001 0010 0100 1001 hex: 0x9249249
(this is : bitMask = shifted | nonshifted)
x &= 0x3ff
x = (x | (x << 16)) & 0x30000ff
x = (x | (x << 8)) & 0x300f00f
x = (x | (x << 4)) & 0x30c30c3
x = (x | (x << 2)) & 0x9249249
因此，对于10位数字和2个交织位（对于32位），您需要执行以下操作！：
x &= 0x3ff
x = (x | x << 16) & 0x30000ff #<<< THIS IS THE MASK for shifting 16 (for bit 8 and 9)
x = (x | x << 8) & 0x300f00f
x = (x | x << 4) & 0x30c30c3
x = (x | x << 2) & 0x9249249
对于21位数字和2个交织位（对于64位），您需要执行以下操作！：
x &= 0x1fffff
x = (x | x << 32) & 0x1f00000000ffff
x = (x | x << 16) & 0x1f0000ff0000ff
x = (x | x << 8) & 0x100f00f00f00f00f
x = (x | x << 4) & 0x10c30c30c30c30c3
x = (x | x << 2) & 0x1249249249249249
对于42位数字和2个交织位（对于128位），您需要执行以下操作（如果需要；-）：
x &= 0x3ffffffffff
x = (x | x << 64) & 0x3ff0000000000000000ffffffffL
x = (x | x << 32) & 0x3ff00000000ffff00000000ffffL
x = (x | x << 16) & 0x30000ff0000ff0000ff0000ff0000ffL
x = (x | x << 8) & 0x300f00f00f00f00f00f00f00f00f00fL
x = (x | x << 4) & 0x30c30c30c30c30c30c30c30c30c30c3L
x = (x | x << 2) & 0x9249249249249249249249249249249L
生成并检查交错模式的Python脚本
import random;
def prettyBinString(x,d=32,steps=4,sep=".",emptyChar="0"):
b = bin(x)[2:]
zeros = d - len(b)
if zeros <= 0:
zeros = 0
k = steps - (len(b) % steps)
else:
k = steps - (d % steps)
s = ""
#print("zeros" , zeros)
#print("k" , k)
for i in range(zeros):
#print("k:",k)
if(k%steps==0 and i!= 0):
s+=sep
s += emptyChar
k+=1
for i in range(len(b)):
if( (k%steps==0 and i!=0 and zeros == 0) or (k%steps==0 and zeros != 0) ):
s+=sep
s += b[i]
k+=1
return s
def binStr(x): return prettyBinString(x,64,4," ","0")
def computeBitMaskPatternAndCode(numberOfBits, numberOfEmptyBits):
bitDistances=[ i*numberOfEmptyBits for i in range(numberOfBits) ]
print("Bit Distances: " + str(bitDistances))
bitDistancesB = [bin(dist)[2:] for dist in bitDistances]
#print("Bit Distances (binary): " + str(bitDistancesB))
moveBits=[] #Liste mit allen Bits welche aufsteigend um 2, 4,8,16,32,64,128 stellen geschoben werden müssen
maxLength = len(max(bitDistancesB, key=len))
abort = False
for i in range(maxLength):
moveBits.append([])
for idx,bits in enumerate(bitDistancesB):
if not len(bits) - 1 < i:
if(bits[len(bits)-i-1] == "1"):
moveBits[i].append(idx)
for i in range(len(moveBits)):
print("Shifting bits by " + str(2**i) + "t for bits idx: " + str(moveBits[i]))
bitPositions = list(range(numberOfBits));
print("BitPositions: " + str(bitPositions))
maskOld = (1 << numberOfBits) -1
codeString = "x &= " + hex(maskOld) + "n"
for idx in range(len(moveBits)-1, -1, -1):
if len(moveBits[idx]):
shifted = 0
for bitIdxToMove in moveBits[idx]:
shifted |= 1<<bitPositions[bitIdxToMove];
bitPositions[bitIdxToMove] += 2**idx; # keep track where the actual bit stands! might get moved several times
# Get the non shifted part!
nonshifted = ~shifted & maskOld
print("nCurrent Mask:tt" + binStr(maskOld))
print("Which bits to shift:t" + binStr(shifted) + "t hex: " + hex(shifted))
shifted = shifted << 2**idx
print("Shifted part (<< " + str(2**idx) + "):t" + binStr(shifted)+ "t hex: " + hex(shifted))
print("NonShifted Part:t" + binStr(nonshifted) + "t hex: " + hex(nonshifted))
maskNew = shifted | nonshifted
print("Bitmask is now :t" + binStr(maskNew) + "t hex: " + hex(maskNew) +"n (this is : bitMask = shifted | nonshifted) n")
#print("Code: " + "x = x | x << " +str(2**idx)+ " & " +hex(maskNew))
codeString += "x = (x | (x << " +str(2**idx)+")) & " + hex(maskNew) + "n"
maskOld = maskNew
return codeString
numberOfBits = 10;
numberOfEmptyBits = 2;
codeString = computeBitMaskPatternAndCode(numberOfBits,numberOfEmptyBits);
print(codeString)
def partitionBy2(x):
l=locals();
exec(codeString,None,l)
return l['x']
def checkPartition(x):
print("Check partition for: t" + binStr(x))
part = partitionBy2(x);
print("Partition is : tt" + binStr(part))
#make the pattern manualy
partC = int(0);
for bitIdx in range(numberOfBits):
partC = partC | (x & (1<<bitIdx)) << numberOfEmptyBits*bitIdx
print("Partition check is :t" + binStr(partC))
if(partC == part):
return True
else:
return False
checkError = False
for i in range(20):
x = random.getrandbits(numberOfBits);
if(checkPartition(x) == False):
checkError = True
break
if not checkError:
print("CHECK PARTITION SUCCESSFUL!!!!!!!!!!!!!!!!...")
else:
print("checkPartition has ERROR!!!!")
相关文章：
- 具有奇怪重复模板模式的派生类中的成员变量已损坏
- 为什么在保护模式下继承升级不起作用
- 如何在全屏模式下(在OpenGL中）使背景透明
- 为什么使用__LINE_的代码在发布模式下在MSVC下编译，而不是在调试模式下
- 派生类是否可以在抽象工厂设计模式中具有数据成员
- 此模式的C++RegEx
- avrogencpp能为模式中的每种类型生成单独的头文件吗
- 使用可变模板的Broadcaster/Listener模式
- c++方法参数只能在linux的发布模式下自行更改
- 资源管理设计模式
- 使用 mod_gsoap 部署服务时，如何在 Gsoap 中更改 soap 上下文的模式？
- C++ 无法在字符数组中使用 for 循环打印字母模式
- 小字符串优化(调试与发布模式）
- 可视化C++：发布模式的运行时库作为'Multi-threaded Debug DLL'
- 如何设计具有不同类型的通知和观察器的观察者模式?
- 在C++的一系列数字中查找重复模式
- 是否允许使用带有"w+"模式的 freopen 进行标准设置？
- C++ 使用存储在动态数组中的文本文件中的数据查找模式
- С++ wxWidgets:代码架构，设计原则和模式
- 生成32位、64位和128位的交织位模式(morton密钥）
