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matrix multiply optimization
matrix multiply optimization
Posted Oct 27, 2007 21:55 UTC (Sat) by bartoldeman (subscriber, #4205)In reply to: matrix multiply optimization by giraffedata
Parent article: Memory part 5: What programmers can do
Because transposition uses O(N^2) accesses and multiplication O(N^3). The accesses in the transposition are more expensive but there are N times fewer than in the multiplication...
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matrix multiply optimization
Posted Oct 27, 2007 22:41 UTC (Sat) by giraffedata (subscriber, #1954) [Link]
Aha. Perfectly clear now. The article neglects to explain this; I'd probably say, "the original traverses mul2 in this expensive nonsequential way 1000 times, whereas the improved version does it only once."