test__insn_x86(9)

💅 test__insn_x86(9) — the x86 instruction decoder test, new-instructions edition 🎀

okay bestie, this one lives in the Kernel API Manual (section 9, iykyk) and it's literally just called test__insn_x86. Let's get into it ✨

---

🦋 SYNOPSIS 🦋

int test__insn_x86 (struct test_suite *test , int subtest );

---

🌸 ARGUMENTS 🌸

• test — -- undescribed -- 🙈 that's it, that's the whole description, the manpage really said "no thoughts, head empty" on this one.
• subtest — also -- undescribed -- 💀 same energy, bestie. No description given, no cap.

---

✨ DESCRIPTION ✨

so this function is basically the vibe check for the x86 instruction decoder 🔥 It runs a test that decodes a whole selection of instructions and then checks the results. Like, did you decode correctly or did you fumble? 👑

and it's not just the decoder — the Intel PT function that further categorizes instructions (that's intel_pt_get_insn, mwah 💋) gets checked too.

now here's the behind-the-scenes lore 🎬 The instructions originally live in insn-x86-dat-src.c, which has been processed by the scripts gen-insn-x86-dat.sh and gen-insn-x86-dat.awk to produce insn-x86-dat-32.c and insn-x86-dat-64.c — and those two get included into this program. i.e. it's giving pipeline realness 🧚

so if you wanna add new instructions to the test, the whole little ritual is: edit insn-x86-dat-src.c, run the gen-insn-x86-dat.sh script, make perf, and then run the test. slay, that's the workflow 💅

and the results? If the test passes, 0 is returned. Otherwise -1 is returned. dramatic but fair 😭

wanna see everything? Use the verbose (-v) option to see all the instructions and whether or not they decoded successfully. that's the main character setting fr fr 👑

---

💜 SEE ALSO 💜

• Kernel file ./tools/perf/arch/x86/tests/insn-x86.c — go read it, it's right there 🫶

---

and that's the whole page, bestie! this icon was brought to you by the source tree ./tools/perf/arch/x86/tests, dated October 2026 — screenshot it, frame it, put it on the fridge 🌈⭐💖