specialize copyto! and multiplication by numbers for Q from qr #39533
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This fixes two performance bugs reported in #38972 and #38972 (multiplication of
Q
fromqr
by aDiagonal
orUniformScaling
). In particular, it improves the performance of generating random orthogonal matrices as described in #38972.Latest Julia nightly (v1.7.0-DEV.448)
This PR
Of course, further performance optimizations are likely possibly by introducing better specializations of various multiplication methods of
Q
by something from the left/right as mentioned in #38972, but this should be a good first step.I cannot add labels to this, but "linear algebra" and "performance" would be appropriate, I think.