Hi,

Thanks for all the suggestions.
Please find attached the modified patch as per your suggestions.

I had missed a mail as pointed by Marc Glisse. Now I have implemented
everything suggested.
Please review the patch and let me know if any further modifications are required.

I have some queries regarding the whole discussions along the course of
this patch.
It would be very helpful for my understanding of the code.

>> /* Fold (A & ~B) - (A & B) into (A ^ B) - B.  */
>> Likewise the fold code handles both constant and non-constant B.

How do we know that fold code handles both constant and non-constant B
and not A?

>> Fold (a * (1 << b)) into (a << b)
>> So either way I think we should only allow nop conversions
>> here (as fold-const.c did).

How do we recognize from the fold-const code that it allows only nop
conversions.

>> We want to minimize the number of lines in match.pd and this doesn't
>> really achieve this compared to duplicating the whole pattern.

Yes. Even, I have the same question to understand this better.
Is it worth and does it acheive any extra optimization after moving
it using simplify and match?

Should I have the other three patterns duplicated and implemented
or leave it in fold-const code?

Thanks,
Naveen