llvm dev - Jul 2010 - [LLVMdev] X + 0.0

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

-Jochen

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.

>
> 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.
>
perhaps in can be implemented using the existing flag 
-enable-unsafe-fp-math.
what do you think?

-Jochen