[PATCH] Added InstCombine Transformation for (A^B)^((~A)&B) -> A&(~B)

Anton Korobeynikov anton at korobeynikov.info
Thu Aug 28 04:55:01 PDT 2014

There are infinitely many expressions which one can form using logical
operations. And for given expression there surely is the minimal form
which one can use to compute.The question is how often such
transformation occur so it's profitable to explicitly match in

Will you please provide some numbers, for example how often such
pattern occurs in LLVM testsuite and in SPEC?

On Thu, Aug 28, 2014 at 1:36 PM, Ankur Garg <ankur29.garg at samsung.com> wrote:
> Hi Anton,
> Thank You for reviewing the patch.
> The simplified expression reduces the number of operations required for the calculation of the original expression from 4 to 3. Just like most of the other transformations, it will reduce the computation. I am not exactly sure what you meant by real world examples. Can you please clarify ?
> Thanks.
> Regards,
> Ankur Garg
> http://reviews.llvm.org/D5002

With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University

More information about the llvm-commits mailing list