What is the difference between signed and unsigned conditional jumps?

Signed comparisons use l/g (less/greater); unsigned ones use b/a (below/above) — the mnemonic tells you how the code treats the value.

* Same bits, two readings: signed uses jl/jg (less/greater), unsigned uses jb/ja (below/above). *

Why it matters: For a value like 0xFFFFFFFF:

• Signed: it's -1, so jl (jump if less) would trigger vs 0
• Unsigned: it's 4294967295, so ja (jump if above) would trigger vs 0

Tip: If you see ja/jb/jbe/jae, the code is treating values as unsigned (common for array bounds, sizes, and addresses).

Go deeper:

• Jcc reference: less/greater vs above/below — spells out that less/greater are signed and above/below are unsigned, and which flags each checks.
• x86 assembly language (Wikipedia) — background on signed vs unsigned interpretation of the same register bits.