EB: use a finite marker instead of NaN for edges with no intercept - #5668
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WeiqunZhang merged 2 commits intoSep 12, 2026
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The edge intercept arrays used a quiet NaN to mark an edge that is entirely regular or entirely covered, and updateIntercept read it back with amrex::isnan. That test is not reliable: under -ffinite-math-only, which -ffast-math implies, both gcc and clang fold std::isnan to false, so the marker becomes undetectable. Cray builds add -ffast-math unconditionally in non-debug mode, and GeometryShop.H is a header, so it also picks up the flags of an application built that way. Replace the marker with EB2::no_intercept, a large finite value that cannot be mistaken for a physical coordinate, and test it with an ordinary comparison. The marker never escapes geometry construction: build_faces reads an intercept only for irregular edges, and intercept_to_edge_centroid then overwrites every entry, so no user-visible data changes.
asalmgren
approved these changes
Sep 11, 2026
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The edge intercept arrays used a quiet NaN to mark an edge that is entirely regular or entirely covered, and updateIntercept read it back with amrex::isnan. That test is not reliable: under -ffinite-math-only, which -ffast-math implies, both gcc and clang fold std::isnan to false, so the marker becomes undetectable. Cray builds add -ffast-math unconditionally in non-debug mode, and GeometryShop.H is a header, so it also picks up the flags of an application built that way.
Replace the marker with EB2::no_intercept, a large finite value that cannot be mistaken for a physical coordinate, and test it with an ordinary comparison.
The marker never escapes geometry construction: build_faces reads an intercept only for irregular edges, and intercept_to_edge_centroid then overwrites every entry, so no user-visible data changes.