[PATCH] Add useAA() to TargetSubtargetInfo

[Hal Finkel]

----- Original Message -----
> 
> On Aug 28, 2013, at 2:42 PM, Hal Finkel <hfinkel at anl.gov> wrote:
> 
> > Andy, et al.,
> > 
> > This patch adds a Boolean useAA() to TargetSubtargetInfo. There are
> > several optional (off-by-default) features in CodeGen that can
> > make
> > use of alias analysis. These features are important for generating
> > code for some kinds of cores (for example the (in-order) PPC A2
> > core). This adds a useAA() function to TargetSubtargetInfo to
> > allow these features to be enabled by default on a per-subtarget
> > basis.
> > 
> > The first patch adds TargetSubtargetInfo::useAA() and uses it to
> > control the default of the -enable-aa-sched-mi feature.
> 
> I’m curious, do you prefer the Option.getNumOccurrences() idiom to
> boolOrDefault options?
> 
> > The second patch uses TargetSubtargetInfo::useAA() to control the
> > defaults of the -combiner-alias-analysis and
> > -combiner-global-alias-analysis options. Why use the same function
> > to control both the scheduling and DAGCombine defaults? Because
> > I'd like to control them both in the same way, and DAGCombine is
> > eventually going to go away and be replaced with something
> > MI-like.
> 
> 
> I wouldn’t design anything yet around the expectation of DAGCombine
> going away. However, I don’t see a problem using the same hook for
> now until someone needs another hook.
> 
> The patch looks great to me. Thanks.

Committed r189563/r189564. Thanks again!

 -Hal

> 
> -Andy
> 
> 
> 

-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory