[#llvm-SplitBlockAndInsertIfThen-07]
= xref:llvm.adoc[llvm]::SplitBlockAndInsertIfThen
:relfileprefix: ../
:mrdocs:

Split a block and insert a then‐branch at an instruction.

== Synopsis

Declared in `<llvm/Transforms/Utils/BasicBlockUtils.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
xref:llvm/Instruction.adoc[Instruction]*
SplitBlockAndInsertIfThen(
    xref:llvm/Value.adoc[Value]* Cond,
    xref:llvm/Instruction.adoc[Instruction]* SplitBefore,
    bool Unreachable,
    xref:llvm/MDNode.adoc[MDNode]* BranchWeights = nullptr,
    xref:llvm/DomTreeUpdater.adoc[DomTreeUpdater]* DTU = nullptr,
    xref:llvm/LoopInfo.adoc[LoopInfo]* LI = nullptr,
    xref:llvm/BasicBlock.adoc[BasicBlock]* ThenBlock = nullptr);
----

== Return Value

The terminator of the then‐block.

== Parameters

[cols="1,4"]
|===
| Name| Description
| *Cond*
| Condition controlling the inserted branch.
| *SplitBefore*
| Instruction at which the block is split.
| *Unreachable*
| Whether the then‐block ends with unreachable.
| *BranchWeights*
| Optional branch‐weight metadata for the new branch.
| *DTU*
| Optional dominator‐tree updater for CFG changes.
| *LI*
| Optional loop info to update.
| *ThenBlock*
| Optional existing block to use as the then‐block.
|===


[.small]#Created with https://www.mrdocs.com[MrDocs]#