[llvm-dev] Regarding Dependence distance dump

[Venkataramanan Kumar via llvm-dev]

Hi,

For the below test case, I need the dependence distance between the array
references  "a[j][i]"  and "a[j-1][i-2]".

--Snip--
int a[5][5];
int b[10];

void test()
{
        for (int j=1;j<5;j++)
                for (int i=2;i<5;i++)
                {
                        a[j][i] = 3.0;
                        b[i]= a[j-1][i-2] ;
                }
}
--Snip-

Compile steps
clang -O1 -emit-llvm -S test.c
opt  -analyze -da dist.ll

I tried dumping the dependence information with LLVM trunk (2018_09_17), it
shows:

Printing analysis 'Dependence Analysis' for function 'test':
da analyze - none!
da analyze - flow [< <>]! <== dumps direction vector
da analyze - none!
da analyze - none!
da analyze - none!
da analyze - consistent output [S 0]!

LLVM Release 6.0.1 dumps the expected distance.
Printing analysis 'Dependence Analysis' for function 'test':
da analyze - none!
da analyze - consistent flow [1 2]!
da analyze - none!
da analyze - none!
da analyze - none!
da analyze - consistent output [S 0]!

In trunk, it is now showing directions instead of distances.
How to get the dependence distance?

regards,
Venkat.
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