[llvm-commits] [PATCH] Address Space Alias Analysis

[Tobias Grosser]

On 10/11/2011 07:11 PM, Tobias Grosser wrote:
> On 10/11/2011 04:08 PM, Justin Holewinski wrote:
>> The attached patch provides a new alias analysis: Address Space Alias
>> Analysis.  This pass is off-by-default and has no impact on generated
>> code unless -asaa is provided to opt.
>>
>> This analysis signals NoAlias for pointers in different address spaces.
>>    The primary target for this pass is GPU back-ends which use LLVM
>> address spaces as a means for differentiating memory types (on-chip
>> shared, off-chip global, etc.) and hence pointers in different address
>> spaces cannot alias.  For OpenCL code compiled with the PTX back-end,
>> this improves performance by over 2x in some of my test kernels due to
>> LLVM using this alias information to remove redundant loads.
>>
>> Is this okay to commit?
>
> Otherwise, the code is pretty straightforward and should be OK to
> commit. As I have limited experience with the alias analysis framework, give
> other people two days to veto (or to 'okay' it entirely). If no problems
> are raised, please commit.

And one point I forgot myself. When commiting please update the 
following website:

http://www.llvm.org/docs/Passes.html

(It still does not mention -tbaa, but nevertheless it would be nice to 
add your -asaa).

Cheers
Tobi