[LLVMdev] What is the purpose of the %”alloca point” line which occurs in llvm code

[Eli Friedman]

On Thu, Aug 20, 2009 at 11:27 PM, David Terei<davidterei at gmail.com> wrote:
> I'm interested in the purpose of the line:
>
> %"alloca point" = bitcast i32 0 to i32          ; <i32> [#uses=0]

It's there as a placeholder for where to insert temporaries: alloca's
go before the bitcast, and actual code generation starts after it.
It's simply a convenience for the front-end; instcombine will
eliminate it, and basically everything else will simply ignore it.

-Eli