_tir_packed_to_unsigned_convert_with_zeros performed the zero-point subtraction in the unsigned packed storage dtype before casting to the requested output dtype. Values below the zero-point therefore wrapped modulo the storage width.
Cast the unpacked field and zero-point to the output dtype before subtraction so asymmetric dequantization preserves negative values.
Add CUDA regression coverage for uint32-packed 4-bit values decoded with a non-zero zero-point.
Fixes#2947
J.W (Jun)
25908d48a6