[llvm-commits] [llvm] r89421 - /llvm/trunk/lib/Analysis/CaptureTracking.cpp

[Chris Lattner]

On Nov 21, 2009, at 7:53 AM, Duncan Sands wrote:

> Hi Chris,
> 
>>> I think this is wrong, consider the following pseudocode example:
>> While this example is "possible" I really don't think this is worth worrying about.  It is not valid C code, is not likely to exist in practice, etc.  Beyond that, comparison against null is really common and we really do want "nocapture" in this cases.
> 
> well, it's a slippery slope :)  Dan later changed this to only allow
> comparisons against malloc return values and other noalias function
> results.

Is such paranoia really worthwhile?  Doing such a thing introduces an 'abstraction penalty' where malloc wrappers now get pessimized where direct calls to malloc don't.

-Chris