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AnswerRe: how to use a work thread write file and the main thread show a carton Pin
Randor 6-Jan-13 18:39
professional Randor 6-Jan-13 18:39 
QuestioncapDriverConnect displays captured frame in CView Pin
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QuestionWhat is the merit to rewrite memcpy? Pin
econy4-Jan-13 8:31
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AnswerRe: What is the merit to rewrite memcpy? Pin
Richard MacCutchan4-Jan-13 10:19
mveRichard MacCutchan4-Jan-13 10:19 
GeneralRe: What is the merit to rewrite memcpy? Pin
econy4-Jan-13 11:31
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GeneralRe: What is the merit to rewrite memcpy? Pin
jeron14-Jan-13 11:49
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GeneralRe: What is the merit to rewrite memcpy? Pin
Richard MacCutchan5-Jan-13 2:20
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AnswerRe: What is the merit to rewrite memcpy? Pin
jschell6-Jan-13 6:02
jschell6-Jan-13 6:02 
econy wrote:
I wonder why the coder didnot use standard C memcpy functio


1. They didn't know it existed.
2. The 'volatile' is important.
3. They thought 'volatile' was important. Perhaps due to the source of the pointers being passed.
4. They are doing a lot of very small copies and the compiler will optimize those with a user method but will not do so with a library method (it will always call the library method rather than attempting to unroll it.)
5. memcpy returns a value, the method doesn't. Perhaps that was important in terms of stack space.
6. The code was originally written with a very early version of the compiler and memcpy was buggy. Or the coder thought it was buggy. No one has challenged that since then.

Could also be a combination of the above.
AnswerRe: What is the merit to rewrite memcpy? Pin
Joe Woodbury7-Jan-13 11:15
professionalJoe Woodbury7-Jan-13 11:15 
QuestionWhat is the benefit using duplicate loop statement [solved] Pin
econy4-Jan-13 5:53
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AnswerRe: What is the benefit using duplicate loop statement Pin
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econy4-Jan-13 7:37
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jeron14-Jan-13 7:58
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GeneralRe: What is the benefit using duplicate loop statement Pin
Richard MacCutchan4-Jan-13 7:59
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AnswerRe: What is the benefit using duplicate loop statement [solved] Pin
CPallini7-Jan-13 0:09
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AnswerRe: What is the benefit using duplicate loop statement [solved] Pin
Joe Woodbury7-Jan-13 11:19
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QuestionIt's too slow to use the DrawDibDraw to draw a frame. Pin
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Questionhow to create font by unicode value? Pin
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Questionwhen writing file,dispaly a animation with avi Pin
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QuestionMS Visual Studio Express 2010, Cygwin, Eclipse together Pin
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