[LLVMdev] X + 0.0

[Dale Johannesen]

On Jul 26, 2010, at 12:38 PMPDT, Jochen Wilhelmy wrote:

>
>>
>> The DAGCombiner appears to do both of these with -enable-unsafe-fp- 
>> math .
>>
> But isn't the DAGCombiner a part of the back-end? Is it possible to  
> get llvm ir
> out of the DAGCombiner? Do you mean the SelectionDAG?

I mean the pass found in DAGCombiner.cpp, which works on the  
SelectionDAG form, yes.

> I further process llvm ir and therefore need a "best possible"  
> optimization on llvm ir.

Currently we don't do any unsafe-math opts in InstCombine.  Not sure  
if this is policy or if it's just that nobody's implemented it.