Fix NaN lanes in the default SimdComplexField::simd_to_exp - #88
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marknefedov wants to merge 1 commit into
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Fix NaN lanes in the default SimdComplexField::simd_to_exp#88marknefedov wants to merge 1 commit into
marknefedov wants to merge 1 commit into
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The default implementation tested whether the modulus was zero on all lanes at once, so mixed zero/nonzero inputs took the division path and computed 0 / 0 on the zero lanes. The resulting NaNs propagated through simd_signum. The zero test is now lane-wise: the division uses a safe modulus and the identity result is selected on the zero lanes. Reachable through num_complex::Complex over any SIMD type that does not override the default (the Wide* wrappers among them); includes a regression test for the mixed-lane and all-zero cases.
marknefedov
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August 14, 2026 21:32
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The default
simd_to_exptests whether the modulus is zero with a whole-vectoris_zero. An input with mixed zero and nonzero lanes takes the division path and computes 0/0 on the zero lanes; the NaNs propagate throughsimd_signum.The zero test is now lane-wise: the division uses a safe modulus (1 on the zero lanes) and the identity result is selected for those lanes afterwards. All-zero and all-nonzero inputs behave exactly as before.
Reachable through
num_complex::Complexover any SIMD type that does not override the default, including theWide*wrappers. Includes a regression test for the mixed-lane and all-zero cases.