Fix numeric_limits digits for NVFP8/6/4
#4070
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miscco
requested changes
Mar 10, 2025
| @@ -194,9 +194,9 @@ class __numeric_limits_impl<__nv_fp8_e4m3, __numeric_limits_type::__floating_poi | |||
| static constexpr bool is_specialized = true; | |||
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| static constexpr bool is_signed = true; | |||
| static constexpr int digits = 3; | |||
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I am actually not sure whether this change is correct.
From cppreference:
For floating-point types, this is the digits of the mantissa (for IEC 559/IEEE 754 implementations, this is the number of digits stored for the mantissa plus one, because the mantissa has an implicit leading 1 and binary point).
These types return false for is_iec559 so I guess digits should be equal to the digits of the mantissa, which in this case is 3 not 4
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This PR fixes
numeric_limits::digitsfor NVFP8/6/4 types.The
digitsstatic member should have the value ofmant_nbits + 1.