LAPACKE: don't allocate transposed matrix in ?lantr_work #382
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@@ Coverage Diff @@
## master #382 +/- ##
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+ Coverage 80.88% 83.24% +2.35%
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Files 1863 1808 -55
Lines 181151 170181 -10970
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- Hits 146528 141664 -4864
+ Misses 34623 28517 -6106
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langou
approved these changes
Mar 25, 2021
weslleyspereira
approved these changes
Mar 25, 2021
christoph-conrads
pushed a commit
to christoph-conrads/lapack
that referenced
this pull request
May 23, 2021
…tr-no-alloc-trans LAPACKE: don't allocate transposed matrix in ?lantr_work
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This PR modifies
LAPACKE_?lantr_workfunctions to avoid allocation (and filling) of the transposed triangular matrixa_t. It uses the standard trick that a lower triangular matrix in row-major storage can be viewed as an upper triangular matrix in column-major (and vice versa) if the parameters are properly adjusted. In fact, this is the same approach thatLAPACKE_?lange_workfunctions use. With this approach a newworkarray must be allocated because the rows and columns are "swapped" between row/column-major (and not because LAPACKE is taking into account that it would make sense to haveworksized differently in row major as I originally misunderstood).I feel a little uneasy because of the lack of any tests but at least for double precision our Gonum test passes.