FA-16094 / Floating-point arithmetic / Member archive

ULP distance leaves the first negative encoding unsigned · case 04

ULP distance leaves the first negative encoding unsigned.

Member previewVariant 4 · 3 implementations · 9 checks per implementation

Case contract

Distance between finite binary64 values in representable steps, treating the two zeros as a single position; NaN or infinity yields null. Negative and positive subnormals are adjacent through zero.

Why this case matters

An offline floating representation model isolates a reproducible arithmetic fault.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
zero signs	`9223372036854775808`	`0`	Failed

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