Hi,

Thanks for the review, views and comments on the issue.

>> -1 is an integer constant, so that's still invalid. It is also invalid for
>> unsigned. The :s are useless since the output is a single insn.

The patch is modified as per your review comments.

Currently the following conditions had been taken care in the patch
as per your suggestions:-

a * c op b * c -> Optimizes for all cases
a * c op b * c -> Does not optimize when  c = 0

a * -c eq/ne b * -c -> Optimizes for all cases
a * -c lt/gt/ge/le b * -c -> Optimizes when c is positive
a * -c lt/gt/ge/le b * -c -> Optimizes and becomes b lt/gt/ge/le when c is negative

Have added a minimal testcase which covers all the above instances.
Please review the patch and let me know if its okay?

Thanks,
Naveen