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Shiven Solanki
cd3dc424fb
core: support fp8 depths in countNonZero and hasNonZero - #30463 Fixes #30461 ### Problem `countNonZeroTab` (`count_non_zero.simd.hpp`) and `hasNonZeroTab` (`has_non_zero.simd.hpp`) have `0` in the `CV_8F_E4M3FN` and `CV_8F_E4M3FNUZ` slots, so `cv::countNonZero` and `cv::hasNonZero` fail with `func != 0` for fp8 input. `cv::findNonZero` already supports both depths since #30341. ### Fix - `CV_8F_E4M3FN`: new `countNonZero8f` / `hasNonZero8f` kernels. Same as the 8u kernels, but the sign bit is ignored so `-0.0` (`0x80`) counts as zero: the vector path reuses the `v_add_wrap(x, x)` compare of the 16f kernels, and the scalar tail uses `CHECK_NZ_FP8(x) = ((x) & 0x7f) != 0`. - `CV_8F_E4M3FNUZ`: the existing 8u kernels. This format has no `-0`; `0x80` is its NaN and counts as non-zero, the same as in `findNonZero`. ### Tests - `CountNonZero1D` now also runs on both fp8 depths. - `HasNonZeroNegZeros` now also covers `CV_8F_E4M3FNC1`. - New `CountNonZeroFP8.sign_bit`, a `TEST_P` over both fp8 depths and n = 1, 100, 1031 (scalar tail, single-vector loop, unrolled loop). It fills a `CV_32F` Mat with random values in ±[0.5, 4), sets every 5th element and the last one to `-0.0`, `NaN` or `+0.0`, converts it to fp8, and checks `countNonZero` / `hasNonZero` against the number of non-zero values set. `-0.0` becomes `0x80` in E4M3FN and must count as zero; `NaN` becomes `0x80` in E4M3FNUZ and must count as non-zero. These fail on current 5.x (`func != 0`) and pass with this patch. All `*NonZero*` and `*FP8*` tests in `opencv_test_core` pass locally on Apple M1 (190 tests), with OpenCL enabled and with `OPENCV_OPENCL_DEVICE=disabled`. ### Pull Request Readiness Checklist See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request - [x] I agree to contribute to the project under Apache 2 License. - [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV - [x] The PR is proposed to the proper branch - [x] There is a reference to the original bug report and related work - [x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable Patch to opencv_extra has the same branch name. - [ ] The feature is well documented and sample code can be built with the project CMake
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