unrolled(9)

✨ NAME ✨

okay bestie, meet unrolled(9) — the Kernel API Manual page for loop attributes that literally ask the compiler to unroll your loop 💅. It's filed under unrolled, and its whole personality is: loop attributes to ask the compiler to unroll it. Slay.

🌸 SYNOPSIS 🌸

unrolled

🦋 DESCRIPTION 🦋

Here's the usage, bestie — copy-paste energy:

#define BATCH 8

unrolled_count(BATCH) for (u32 i = 0; i < BATCH; i++) // loop body
without cross-iteration dependencies

So yeah: unrolled_count(BATCH) goes right before that for loop, and the loop body is the no-cross-iteration-dependencies vibe. 👑

⚠️ plot twist: this is only a hint. The compiler is free to disable unrolling if it thinks the count is suboptimal and may hurt performance and/or hugely increase object code size. No cap — it can ghost your unroll 😭.

Not having any cross-iteration dependencies — i.e. when iter x + 1 depends on what iter x will do with variables — is not a strict requirement, but it provides best performance and object code size. That's the highkey ideal scenario ✨.

🌈 Available only on Clang and GCC 8.x onwards. If your compiler is older, this is not the vibe.

💜 SEE ALSO 💜

Kernel file ./include/linux/unroll.h — go peek, bestie 🫶.

made with 💖 from ./include/linux — October 2026 — unrolled(9) out 💅