Click here to Skip to main content
15,886,919 members
Home / Discussions / C / C++ / MFC
   

C / C++ / MFC

 
GeneralRe: DWORD Time Puzzle Pin
Stuart Dootson25-Sep-09 10:48
professionalStuart Dootson25-Sep-09 10:48 
GeneralRe: DWORD Time Puzzle Pin
phil241527-Sep-09 23:05
phil241527-Sep-09 23:05 
QuestionHow to prevent accelerators while certain childs have focus? Pin
i96danma24-Sep-09 5:28
i96danma24-Sep-09 5:28 
QuestionFast square root algorithm and using SSE Intrinsics to boost floating point calculation performance Pin
D_code_writer24-Sep-09 4:20
D_code_writer24-Sep-09 4:20 
AnswerRe: Fast square root algorithm and using SSE Intrinsics to boost floating point calculation performance Pin
Michael Schubert24-Sep-09 5:31
Michael Schubert24-Sep-09 5:31 
AnswerRe: Fast square root algorithm and using SSE Intrinsics to boost floating point calculation performance Pin
molesworth24-Sep-09 6:04
molesworth24-Sep-09 6:04 
AnswerRe: Fast square root algorithm and using SSE Intrinsics to boost floating point calculation performance Pin
Rick York24-Sep-09 6:56
mveRick York24-Sep-09 6:56 
AnswerRe: Fast square root algorithm and using SSE Intrinsics to boost floating point calculation performance Pin
Luc Pattyn24-Sep-09 7:55
sitebuilderLuc Pattyn24-Sep-09 7:55 
Hi,

is you application already using MMX/SSE code? is it vectorized at all?

if not, it won't make sense to use SSE just to get a square root; you would have to get the data in and out the vector processor, which would forego all the speed gain you might achieve.

So just apply regular optimization on doubles. Some of these have already been mentioned:
- avoid SQRT; don't use it when it isn't necessary.
- use an approximation, if that is acceptable.
- for the range of numbers you're interested in, find a fast way (often a polynomial, or something smart, sometimes called "magic").
- if you need SQRT on a series of related numbers, try using each result as the initial estimate for the next.

Smile | :)

Luc Pattyn

Local announcement (Antwerp region): Lange Wapper? Neen!


AnswerRe: Fast square root algorithm and using SSE Intrinsics to boost floating point calculation performance Pin
D_code_writer24-Sep-09 18:51
D_code_writer24-Sep-09 18:51 
QuestionCombine Two bmp images into one Pin
Game-point24-Sep-09 3:47
Game-point24-Sep-09 3:47 
AnswerRe: Combine Two bmp images into one Pin
Richard MacCutchan24-Sep-09 4:12
mveRichard MacCutchan24-Sep-09 4:12 
QuestionProperty sheet and page Pin
hrishiS24-Sep-09 3:46
hrishiS24-Sep-09 3:46 
AnswerRe: Property sheet and page Pin
David Crow24-Sep-09 4:02
David Crow24-Sep-09 4:02 
GeneralRe: Property sheet and page Pin
hrishiS24-Sep-09 4:26
hrishiS24-Sep-09 4:26 
GeneralRe: Property sheet and page Pin
David Crow24-Sep-09 4:33
David Crow24-Sep-09 4:33 
GeneralRe: Property sheet and page Pin
hrishiS24-Sep-09 5:02
hrishiS24-Sep-09 5:02 
GeneralRe: Property sheet and page Pin
David Crow24-Sep-09 5:09
David Crow24-Sep-09 5:09 
GeneralRe: Property sheet and page Pin
Chuck O'Toole24-Sep-09 15:46
Chuck O'Toole24-Sep-09 15:46 
GeneralRe: Property sheet and page Pin
David Crow25-Sep-09 2:41
David Crow25-Sep-09 2:41 
GeneralRe: Property sheet and page Pin
Chuck O'Toole25-Sep-09 4:02
Chuck O'Toole25-Sep-09 4:02 
AnswerRe: Property sheet and page Pin
Chuck O'Toole25-Sep-09 4:04
Chuck O'Toole25-Sep-09 4:04 
QuestionHow to hide SIP with mutiple dialog boxes? Pin
Rushikesh12324-Sep-09 2:55
Rushikesh12324-Sep-09 2:55 
Questioni have written create process now i want to terminate process but it is not terminated Pin
prerananit24-Sep-09 2:42
prerananit24-Sep-09 2:42 
AnswerRe: i have written create process now i want to terminate process but it is not terminated Pin
Nuri Ismail24-Sep-09 2:45
Nuri Ismail24-Sep-09 2:45 
GeneralRe: i have written create process now i want to terminate process but it is not terminated Pin
CPallini24-Sep-09 3:01
mveCPallini24-Sep-09 3:01 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.