ifcvt/crossjump patch: Fix PR 42496, 21803

[Bernd Schmidt]

On 07/24/2010 12:05 AM, Eric Botcazou wrote:
>> Before you do that, here's a new version.  This corrects a few errors in
>> the register lifetime handling, and adds support for moving across two
>> basic blocks, which is very useful for switch statements but happens in
>> other cases as well.  
> 
> This implementation really moves insns whereas cross-jumping, the reversed  
> transformation, is implemented by means of operations on the CFG.  Although 
> this is probably not as straightforward in this direction, did you consider 
> the CFG approach instead?  Wouldn't it simplify a little the integration in 
> the cfgcleanup.c framework?

Please be more specific about what you envision.


Bernd