Speeding bitand / bitshift and type conversion
显示 更早的评论
We have a uint32 data word that is made of two uint16 variables, the first 16 bits is variable #1, the second 16 bits is variable #2. To convert, we are using bitand and type casting:
% Take 32-bit DataWord, convert into two 16-bit variables:
Var1 = uint16(bitshift(bitand(DataWord1,uint32(4294901760)),-16)); % 4294901760 = 0b11111111111111110000000000000000
Var2 = uint16(bitand(DataWord1,uint32(65535))); % 65535 = 0b00000000000000001111111111111111
We do this on an incoming data stream, and unfortunatley, our code above is too slow.
Originally we were using bitget, but it returns a row vector of bits, so getting that row vector into a single uint16 variable was even slower.
Thanks for any help to speed up the above.
回答（1 个）
James Tursa
2020-3-9
编辑：James Tursa
2020-3-9
Try this:
DataWord16 = typecast(DataWord1,'uint16'); % shared data copy for later versions of MATLAB
Var1 = DataWord16(1:2:end);
Var2 = DataWord16(2:2:end);
3 个评论
Walter Roberson
2020-3-9
In some cases you would swapbytes() the result of typecast
James Tursa
2020-3-9
Good point.
C R
2020-3-10
类别
在 帮助中心 和 File Exchange 中查找有关 Data Type Conversion 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
