FA-16059 / Floating-point arithmetic / Member archive

Exponent adjustment discards the mantissa sign · case 04

Exponent adjustment discards the mantissa sign.

Member previewVariant 4 · 3 implementations · 10 checks per implementation

Case contract

Recompose finite binary64 x after changing its exponent by integer shift. Return hex value, or signed overflow marker. Scaling preserves negative zero and gradual underflow. Inputs exclude NaN and infinity.

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
scale down	`"0x1.8000000000000p-4"`	`"-0x1.8000000000000p-4"`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.