STRUCT ANNOTATED_OP_LOC(9)

✨ struct annotated_op_loc(9) ✨

okay so bestie, welcome to struct annotated_op_loc(9) — straight out of the Kernel API Manual and honestly? it's giving "small struct, big responsibilities" 💅 this little cutie is your go-to for Location info of instruction operand 🎀 like it literally exists to tell you where an operand lives and what it's doing. no cap.

🌸 SYNOPSIS 🌸

struct annotated_op_loc {
    int reg1;
    int reg2;
    int offset;
    u8 segment;
    bool mem_ref;
    bool multi_regs;
    bool imm;
 };

that's the whole vibe. seven fields, zero drama. let's meet them 🫶

💖 Members 💖

• reg1 — the first register in the operand. the main character of registers, if you will 👑
• reg2 — the second register in the operand. yes bestie, sometimes there's a whole second one 😭
• offset — the memory access offset in the operand. it's an offset. it offsets. we love that for it ✨
• segment — the segment selector register (type u8, very compact, very demure 🎀)
• mem_ref — a bool that answers the question "does the operand access memory?" 🧚 either it does or it doesn't, no in-between
• multi_regs — a bool telling you whether the second register is actually used 👀 so like, reg2 might be sitting there existing but not being used. relatable honestly
• imm — a bool for whether the operand is an immediate value — and the important detail: it lives in offset 🍓 so like, the offset field is doing double duty, iykyk

🦋 reminder: imm means the immediate value is stored in offset. do not go looking in a separate field, bestie, it's not there, fr fr.

🌈 SEE ALSO 🌈

all the siblings in the family tree 💜:

• struct sym_hist(9)
• struct cyc_hist(9)
• struct annotated_source(9)
• struct annotated_branch(9)
• struct annotated_insn_loc(9)
• struct annotated_basic_block(9)

and if you wanna come stare at the source yourself, it's living its best life in the kernel file ./tools/perf/util/annotate.h 🔥

and that's the whole page, bestie!! 💕 big slay to the folks at ./tools/perf/util — this doc dropped October 2026, so mark your calendar and stan accordingly ⭐ 👑 ✨