[llvm-commits] [llvm] r85346 - in /llvm/trunk: include/llvm/CodeGen/Passes.h lib/CodeGen/BranchFolding.cpp lib/CodeGen/BranchFolding.h lib/CodeGen/IfConversion.cpp lib/CodeGen/LLVMTargetMachine.cpp lib/Target/ARM/ARMTargetMachine.cpp

[Chris Lattner]

On Oct 28, 2009, at 10:21 AM, Dale Johannesen wrote:

>> If so, yes, I think that would work.  In fact, I think it would be a
>> good idea.  At -O2, that would mean that we would be optimizing for
>> performance at a small cost in code size.  That's a more aggressive
>> change than mine, but I think it would be a good idea.
>>
>> Shall I go ahead with that?
>
> Branch folding is a size optimization.  It would not surprise me if
> turning it off completely at
> -O3 was the right thing for performance.  My only strong belief is
> that any change should be based on measurements, not arguments.

Doesn't it also do some code layout to encourage better fall-throughs  
etc?

-Chris