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dft_tools/test/speed
Olivier Parcollet b534936589 Fix matrix * alias issue and adapt det_manip
- The previous version of the * operator for matrix was too clever.
It was giving a lazy object and then rewriting C = A *B into gemm (a,A,B,0,C).
The pb was in case of aliasing : when e.g. C = A, or is a part of A.
gemm is not correct that case, and as a result generic code like
a = a *b
may not be correct in matrix case, which is unacceptable.

- So we revert to a simple * operator for matrix
that does immediate computation.
Same thing for matrix* vector

- we also suppress a_x_ty class.

-> for M = a * b,
when M is a matrix, there is no overhead due to move assignment
-> however, when M is a view, there is an additionnal copy.

-Correctness comes first, hence the fix.
However, if one wants more speed and one can guarantee that
there is no aliasing possible, then one has to write a direct gemm call.

-> det_manip class was adapted, since in that case, we can show there
no alias, and we want the speed gain, so the * ops where replaced
by direct blas call (using the array blas interface).

-> also gemm, gemv, ger were overloaded in the case the return
matrix/vector (i.e. last parameter of the function) is not an lvalue,
but a temporary view created on the fly.
2013-09-11 18:49:22 +02:00
..
apply_on_tuple_s.cpp First commit : triqs libs version 1.0 alpha1 2013-07-17 19:24:07 +02:00
array1.cpp Fix matrix * alias issue and adapt det_manip 2013-09-11 18:49:22 +02:00
array2.cpp First commit : triqs libs version 1.0 alpha1 2013-07-17 19:24:07 +02:00
array_lazy_assign.cpp First commit : triqs libs version 1.0 alpha1 2013-07-17 19:24:07 +02:00
array_short1.cpp Fix matrix * alias issue and adapt det_manip 2013-09-11 18:49:22 +02:00
array_view.cpp arrays: new ref counting and weak views 2013-07-23 08:13:44 +02:00
clef1.cpp First commit : triqs libs version 1.0 alpha1 2013-07-17 19:24:07 +02:00
clef_common.hpp clef : new version using lvalues and moving rvalues 2013-09-08 15:04:12 +02:00
CMakeLists.txt First commit : triqs libs version 1.0 alpha1 2013-07-17 19:24:07 +02:00
gemv.cpp Fix matrix * alias issue and adapt det_manip 2013-09-11 18:49:22 +02:00
gf_s.cpp [API BREAK] rename directory gf -> gfs 2013-07-29 11:53:02 +02:00
isol_array_foreach_pb.cpp First commit : triqs libs version 1.0 alpha1 2013-07-17 19:24:07 +02:00
matmul_s.cpp First commit : triqs libs version 1.0 alpha1 2013-07-17 19:24:07 +02:00
pool.cpp First commit : triqs libs version 1.0 alpha1 2013-07-17 19:24:07 +02:00
speed_tester.hpp First commit : triqs libs version 1.0 alpha1 2013-07-17 19:24:07 +02:00