Fixed bug in parallelization in MPS simulator. #292
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…push_back. Need to use assignment instead.
merav-aharoni
changed the title
| #pragma omp parallel for | ||
| #else | ||
| #pragma omp parallel for collapse(2) | ||
| #endif | ||
| for(uint_t row = 0; row < num_rows; row++) { |
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We need to change the type of row to int_t due to incompatibilities with Windows OpenMP support.
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Corrected both places as you pointed out.
It is a problem to catch failures that only happen non-deterministically. I can only suggest running the unittest a few times.
We also use another kind of testing here - we create random circuits and then compare results between the mps and the statevector. If you are interested, I can add these somewhere as well.
| #pragma omp parallel for | ||
| #else | ||
| #pragma omp parallel for collapse(2) | ||
| #endif | ||
| for(uint_t row = 0; row < num_rows; row++) { | ||
| for(uint_t col = 0; col < num_cols; col++) { |
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We need to chage this type too: uint_t col => int_t col
CHANGELOG.md
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| @@ -35,6 +35,7 @@ Removed | |||
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| Fixed | |||
| ----- | |||
| - Bug in handling parallelization in matrix_product_state.cpp | |||
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We need to add the number of the PR at the end of this line (see the other entries) :)
* Fixed bug in parallelization. It does not work correctly with vector push_back. Need to use assignment instead.
* Fixed bug in parallelization. It does not work correctly with vector push_back. Need to use assignment instead.
Summary
There was an "omp parallel" on a for loop that had a vector that was assigned values using push_back. That caused undeterministic behavior. Changed the push_back to assignment.
Details and comments