Port netcdf c 3093#260
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Port netcdf-c PR #3093 -- all quantization loops in ccr_bgr() and ccr_gbr() now skip ±0.0 and NaN via (val != 0.0 && !isnan(val)), superseding the bit-pattern u*_ptr[idx] != 0U checks that only caught +0.0. The has_mss_val == 0 fallback now uses NaN as a no-op sentinel (NC_FILL_FLOAT/DOUBLE macros dropped).
The loop bodies have well-defined behavior only for finite inputs:
BitRound's per-value bit-shift becomes an out-of-range shift on ±Inf
(undefined behavior), and BitGroom's loop turns ±Inf bit patterns
into NaN by ORing low mantissa bits. Both guards now use isfinite(val)
instead of !isnan(val) to block ±Inf in addition to NaN. New h5filter_specials_{bitround,bitgroom} round-trip tests
write NaN, ±Inf, ±0.0, and normal values via H5Pset_filter, read back,
and assert in C that the special values pass through unchanged while
at least one normal value was quantized.
ajelenak
requested review from
bmribler,
brtnfld,
fortnern,
glennsong09,
jhendersonHDF,
lrknox and
mattjala
as code owners
bmribler
requested changes
Jun 23, 2026
bmribler
reviewed
Jun 24, 2026
bmribler
approved these changes
Jun 25, 2026
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ccr_gbr() now skip ±0.0 and NaN.