# Lower

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## Table of contents

-   [Overview](#overview)

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## Overview

Lowering takes the SemIR and produces LLVM IR. At present, this is done in a
single pass, although it's possible we may need to do a second pass so that we
can first generate type information for function arguments.

Lowering is done per `SemIR::InstBlock`. This minimizes changes to the
`IRBuilder` insertion point, something that is both expensive and potentially
fragile.