code-generation-and-backends

code-generation-and-backends is a skill for Claude Code, Codex from mohitmishra786/low-level-dev-skills. It costs 59 tokens per session (827 once invoked), scanned A, original, MIT.

A guide to the LLVM compiler stage that turns intermediate code into machine instructions for a particular processor architecture.

In plain words
What is it for?
Use it to read llc output, understand instruction selection, register allocation, scheduling, and target lowering, or plan LLVM support for a new processor.
Why use it?
It explains why the compiler changes operations or adds steps for a target processor, helping diagnose incorrect assembly or understand what porting to a new architecture involves.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to read llc output, understand instruction selection, register allocation, scheduling, and target lowering, or plan LLVM support for a new processor.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/mohitmishra786/low-level-dev-skills/code-generation-and-backends
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add mohitmishra786/low-level-dev-skills --skill code-generation-and-backends
Clone the repo
git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for code-generation-and-backends

README.md
[![agentmods](https://agentmods.dev/badge/skills/mohitmishra786/low-level-dev-skills/code-generation-and-backends/github.svg)](https://agentmods.dev/skills/mohitmishra786/low-level-dev-skills/code-generation-and-backends)
Your own site
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Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for code-generation-and-backends

Your own site · 80×15
<a href="https://agentmods.dev/skills/mohitmishra786/low-level-dev-skills/code-generation-and-backends"><img src="https://agentmods.dev/badge/skills/mohitmishra786/low-level-dev-skills/code-generation-and-backends.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 59 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 827 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00059 $0.00827
Opus 5 $0.00030 $0.00413
Sonnet 5 $0.00012 $0.00165
Haiku 4.5 $0.00006 $0.00083

Measured 9d ago against content hash a7dfd642aeb3, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

code-generation-and-backends scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/compiler-internals/code-generation-and-backends/SKILL.md · 96 lines

How it starts

The opening of the file, as written. The whole thing — 96 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Code Generation and Backends

Purpose

Overview LLVM (and general compiler) backend code generation: IR legalization, SelectionDAG instruction selection, register allocation, assembly emission, and what adding a new target entails — complementing IR skills and skills/compiler-internals/llvm-passes.

When to Use

  • Reading llc output for a specific target
  • Understanding why IR type legalizer inserted extra ops
  • Evaluating porting compiler to new architecture (high level)
  • Debugging wrong code at asm layer (not IR)

Workflow

1. Backend pipeline (LLVM)

LLVM IR per function
├── IR legalizer (types/ops target supports)
├── SelectionDAGBuilder
├── LegalizeTypes / LegalizeOps
├── Instruction selection (pattern match TableGen)
├── Scheduling (pre-RA)
├── Register allocation
├── Prolog/epilog insertion
└── AsmPrinter → .s object

2. llc usage

clang -c -emit-llvm -O2 -o foo.bc foo.c
llc -march=aarch64 -O2 foo.bc -o foo.s
llc -march=riscv64 -O2 foo.bc -o foo-rv.s

3. TableGen patterns (conceptual)

def ADD32rr : Pat<(add i32 GPR:$a, GPR:$b),
                  (ADD32rr GPR:$a, GPR:$b)>;

Patterns map DAG nodes to machine instructions. .td files define registers, calling conv, instr formats.

4. Calling convention lowering

ABI rules become CC_AArch64 / CC_X86_64 in TableGen — ties to skills/computer-architecture/abi-and-calling-conventions.

5. Target triple

clang --target=arm-none-eabi -c -O2 foo.c
llc -mtriple=thumbv7em-none-eabi foo.bc

Mismatch between triple and CPU features (+neon, +crc) causes legalizer failures or suboptimal code.

6. Adding a target (outline)

  1. Define register classes and instr formats in TableGen
  2. Implement lowering hooks (TargetLowering)
  3. AsmPrinter and MC layer for relocations
  4. Builtin calling convention and ELF/COFF object writer

Full port is large — reuse existing backend closest to arch.

7. Agent usage

/code-generation-and-backends Trace how this IR add becomes AArch64 ADD instruction

Read the full file on GitHub · 96 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 96 lines · 59 tokens per session scan A a7dfd642aeb3

Subscribe to this mod's changes

code-generation-and-backends is a skill published in the GitHub repository mohitmishra786/low-level-dev-skills (198 stars, last pushed 2mo ago), licensed MIT. It adds 59 tokens to every session and 827 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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