Fixture written by libhdf5 2.2.0 (built from tag 2.2.0) through ctypes:
every bit pattern of FP4 E2M1, FP6 E2M3/E3M2, FP8 E4M3/E5M2 and a
bfloat16 LE/BE set, as datasets and attributes, with what H5Dread/H5Aread
return into double and float and the conversion exceptions libhdf5
raises. clawhdf5 already decoded every value as libhdf5 does, including
an all-ones exponent as inf/NaN in the OCP formats that have none
(documented as a deliberate match in known-issues).
- data_read: NaNs of non-native float layouts get libhdf5's bits (sign
kept, every mantissa bit set) in f64 and f32.
- h5rs dump/ls name these types as h5dump/h5ls 2.x do
(H5T_FLOAT_F4E2M1, "FP4 E2M1 4-bit float", float4-e2m1 ...), checked
against h5dump 2.2.0's output of the fixture.
- Python bindings read them as h5py 3.16 does (float32 for bfloat16,
float16 for the 1-byte formats, file byte order, same bytes as h5py);
writing them in 'r+' is refused.
Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
