[llvm-commits] [PATCH] Add Pattern ID Information

[Jakob Stoklund Olesen]

On Aug 5, 2011, at 4:07 PM, Villmow, Micah wrote:

>> We added AsmPrinterFlags almost two years ago. In that time, nobody has
>> defined more flags, and the existing ReloadReuse flag is only written
>> by VirtRegRewriter.cpp which isn't even in the default pipeline any
>> more.
>> 
> [Villmow, Micah] This is extremely useful for our internal backend. I use it
> to encode per instruction information that does not fit into the 'flags' 
> field without having to extend the MachineInstr class. 

I think we discussed this before. You really shouldn't be using AsmPrinterFlags to carry anything important, it is intended for debugging annotations.

You would be better off using an immediate operand to encode your extra semantics.

/jakob