[LLVMdev] CodeGenOpt

[Devang Patel]

On Feb 24, 2011, at 8:14 AM, David A. Greene wrote:

> Chris Lattner <clattner at apple.com> writes:
> 
>>> class CodeGenOpt {
>>> ...
>>> public
>>> getOptLevel() ...;
>>> getFPLevel() ...;
>>> getMemLevel() ...;
>>> };
>>> 
>>> Does this sound reasonable?
>> 
>> I don't think that this is the right way to go.  Higher level
>> decisions like that should affect your choice of passes to schedule.
> 
> But there's no way to do that at the codegen level.  LLVMTargetMachine
> keys off of CodeGenOpt.

If you look at addCommonCodeGenPasses() then you'll see that CodeGenOpt is not used to select passes. Yes, CodeGenOpt::None is checked at few places to ensure that we are doing optimization, but it is not checking *level* of optimization.

If seems you want better approach to influence pass selection in addCommonCodeGenPasses()  for your needs. If so, why not try to do what we did in 'opt' using StandardPasses.h ? (Note, I have not thought through this suggestion, I am just thinking loudly here)

-
Devang