Bitwise Tricks in C

From the C cheat sheet · Bit Manipulation · verified Jul 2026

Bitwise Tricks

Masks, flags, and shifts.

c
// Quick Reference
x & mask     // test bits
x | flag     // set bits
x & ~flag    // clear bits
x ^ flag     // toggle bits
x << n       // shift left
💡 1u << n makes a mask for bit n; use it to set, clear, toggle, or test that bit.
⚡ Combine flags with |, test with &, remove with & ~flag.
📌 Prefer unsigned types for bit work - right-shifting signed negatives is implementation-defined.
🟢 x << 1 and x >> 1 are fast multiply/divide by 2 (for non-negative values).
bitwiseflags
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