[#llvm-LiveRegUnit]
= xref:llvm.adoc[llvm]::LiveRegUnit
:relfileprefix: ../
:mrdocs:

Live physical register unit with its defining or reading operand.

== Synopsis

Declared in `<llvm/CodeGen/MachineTraceMetrics.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
struct LiveRegUnit;
----

== Description

Keep track of physreg data dependencies by recording each live register unit. Associate each regunit with an instruction operand. Depending on the direction instructions are scanned, it could be the operand that defined the regunit, or the highest operand to read the regunit.

== Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:llvm/LiveRegUnit/2constructor.adoc[`LiveRegUnit`]         [.small]#[constructor]#
| Construct a live regunit entry for `RU.`
| xref:llvm/LiveRegUnit/getSparseSetIndex.adoc[`getSparseSetIndex`] 
| Return the sparse‐set index for this regunit.
|===


== Data Members

[cols="1,4"]
|===
| Name| Description
| xref:llvm/LiveRegUnit/Cycle.adoc[`Cycle`] 
| Cycle at which `RegUnit` is defined or last read.
| xref:llvm/LiveRegUnit/MI.adoc[`MI`] 
| Instruction associated with `Op.`
| xref:llvm/LiveRegUnit/Op.adoc[`Op`] 
| Operand index of `MI` that defines or reads `RegUnit.`
| xref:llvm/LiveRegUnit/RegUnit.adoc[`RegUnit`] 
| Physical register unit being tracked.
|===



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