Problem with LoopDependenceAnalysis

Shanmuhka wrote:

I looked at the sanjoys patch for SIV Test. And i figured out that this is exactly what i need.
as the comments said, check if subscript A can possibly have the same value as B in analyseSIV(A,B)
but i didn't get How to use this information ?

lets just say in the above program
When i use depends function it shows the dependency from load of x to store in x. similarily for array a.
but how can i be sure that there is no dependence from store of x to load of x in the next iteration ?

LoopDependenceAnalysis isn't really ready for use yet.
When it is ready, you would be able to ask explicitly:

    Is there a dependence from the store of x to (one of) the loads of x?

For your example, it would tell you that no such dependence exists.

Preston

Hi Preston,

Shanmuhka wrote:

I looked at the sanjoys patch for SIV Test. And i figured out that this is exactly what i need.
as the comments said, check if subscript A can possibly have the same value as B in analyseSIV(A,B)
but i didn’t get How to use this information ?

lets just say in the above program
When i use depends function it shows the dependency from load of x to store in x. similarily for array a.
but how can i be sure that there is no dependence from store of x to load of x in the next iteration ?

LoopDependenceAnalysis isn’t really ready for use yet.
When it is ready, you would be able to ask explicitly:

Is there a dependence from the store of x to (one of) the loads of x?

For your example, it would tell you that no such dependence exists.

Its not showing no such dependence exist.
I am new to llvm.
So i dont know how to use it properly.
could you please tell me how do i use it?