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Bug 483 - Optimize outer products for non rank-1 update operation
Summary: Optimize outer products for non rank-1 update operation
Alias: None
Product: Eigen
Classification: Unclassified
Component: Core - matrix products (show other bugs)
Version: unspecified
Hardware: All All
: Normal Unknown
Assignee: Nobody
Depends on:
Blocks: 3.2
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Reported: 2012-06-28 18:50 UTC by Gael Guennebaud
Modified: 2019-12-04 11:45 UTC (History)
0 users


Description Gael Guennebaud 2012-06-28 18:50:32 UTC
Currently the outer product impl. is optimized for:

 A += v1 * v2.transpose();

making a simple:

A = v1 * v2.transpose();

significantly slower than what it could be because of the additional A.setZero() and additional adds.
Comment 1 Gael Guennebaud 2013-02-25 13:32:49 UTC
Not very elegant, but it works:
changeset:   086be9eedd4b
user:        ggael
date:        2013-02-25 13:31:42
summary:     Fix bug 483: optimize outer-products to skip setZero and a scalar multiple when not needed.
Comment 2 Nobody 2019-12-04 11:45:28 UTC
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