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b534936589
- 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.
19 lines
549 B
C++
19 lines
549 B
C++
#include "./common.hpp"
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using std::cout; using std::endl;
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using namespace triqs::arrays;
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// to be extended to more complex case
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// calling lapack on view to test cache securities....
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//
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int main() {
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array<std::complex<double>,3> TMPALL (2,2,5); TMPALL()=-1;
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matrix_view<std::complex<double> > TMP ( TMPALL (range(), range(), 2));
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matrix<std::complex<double> > M1(2,2), Res(2,2);
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M1()=0; M1(0,0) = 2; M1(1,1) = 3.2;
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Res()=0; Res(0,0) = 8; Res(1,1) = 16.64;
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TMP() =0;
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TMP() = M1*( M1 + 2.0 );
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assert_all_close(TMP(), Res, 1.e-10);
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}
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