Fix modification of rotation matrix in Givens rotation#1379
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In the Givens rotation function, the rotation matrix was modified, leading to different results when the function was called again with the same rotation matrix. The function now makes a copy of the matrix. A test was added to ensure subsequent calls are identical.
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This pull request modifies optimal_givens_decomposition to copy the input unitary matrix before processing, preventing side effects from in-place modifications. A corresponding unit test, test_consecutive_optimal_givens_decomposition, has been added to verify that consecutive calls with the same matrix produce identical circuits. There are no review comments, and I have no additional feedback to provide.
mhucka
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Jun 26, 2026
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Fixes #761 (supersedes #1344). In the
optimal_givens_decomposition()function, the rotation matrix was modified, leading to different results when the function was called again with the same rotation matrix. The function now makes a copy of the rotation matrix parameter to avoid this issue. A test was added to ensure consecutive calls tooptimal_givens_decomposition()yield identical results.