[LLVMdev] Tail Duplication Questions

[dag at cray.com]

Arnold Schwaighofer <arnolds at codeaurora.org> writes:

> http://llvm.org/viewvc/llvm-project/llvm/tags/RELEASE_31/final/lib/CodeGen/Passes.cpp?revision=156747&view=markup
>
> void TargetPassConfig::addMachineSSAOptimization() {
>   // Pre-ra tail duplication.
>   if (addPass(EarlyTailDuplicateID) != &NoPassID)
>     printAndVerify("After Pre-RegAlloc TailDuplicate");
>
>
> /// Add passes that optimize machine instructions after register allocation.
> void TargetPassConfig::addMachineLateOptimization() {
>   // Branch folding must be run after regalloc and prolog/epilog insertion.
>   if (addPass(BranchFolderPassID) != &NoPassID)
>     printAndVerify("After BranchFolding");
>
>   // Tail duplication.
>   if (addPass(TailDuplicateID) != &NoPassID)
>     printAndVerify("After TailDuplicate");

Hmm.  Why doesn't -tailduplication show up in llc -help?