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Blue Forest http://www.lslnet.com at 10:18 on June 6, 2006
"<c Language adapter and Implementation", "code of a doubt In Chapter 13 "vectors" section of the code are :
# Nbytes (practically) ((((practically) + 8 - 1) & (~ (8 - 1))) /8)
According to the book means that the Acer used to calculate [len/8], the question is :
1. I have seen this code to write and direct len/8 find no difference between Asia because :
(Practically + 8 - 1) & (~ (8 - 1)), is len+7 front, behind and on 7 premium is not that of seven away?
280-1 = 7, then why should be rewritten 8-1?
3. I carefully thought for a moment, think that this issue should be the exception and integer calculation, in the end what? |
"<c Language adapter and Implementation", "code of a doubt Of course there is a distinction. This procedure, if len<8, is the one and len/8 integer, if the len<8 is 0. |
"<c Language adapter and Implementation", "code of a doubt
| "<c Language adapter and Implementation", "code of a doubt In fact, nbytes (n) = n / 8 +1
And
If len<8, are given 1;
No contradiction!
I saw the wording to read, but I have no problem 8-1 and 7 clear; Repeat tomorrow ask the Supreme find! |
"<c Language adapter and Implementation", "code of a doubt Give you another example :
N = 9;
N/8==1;
(N+7) /8 ==2;
This is to take the whole, and not lose spaces
(N+7) &&! (8-1) and went to the same role |
"<c Language adapter and Implementation", "code of a doubt Right there! |
"<c Language adapter and Implementation", "code of a doubt (Len+8-1) & (~ (8-1)) = (len+7) /8, meaning two months is practically required 229 spaces occupied by the byte count.
After a written translation of the former than the latter wording of computational efficiency.
Written (8-1), which was to improve the readability and easy replacement. For example, eight replaced 16, it becomes practically two months short of the 229 spaces occupied by the few. |
"<c Language adapter and Implementation", "code of a doubt Agree bierdaci |
"<c Language adapter and Implementation", "code of a doubt -->
So that it makes sense |
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