On Tue, Sep 1, 2015 at 10:57 AM, Hurugalawadi, Naveen
<[email protected]> wrote:
> Hi,
>
> Please find attached the patch "pr67351.patch" that implements the
> pattern << N & >> N optimizers.
+ (bit_and @0 (lshift { build_minus_one_cst (type); } @1))))
please use
(bit_and @0 { wide_int_to_tree (type, wi::lshift (-1, @1)); })
and wi::arshift for the other pattern. It should then be possible
to drop the tree_fits_uhwi_p tests and replace the precision test
with wi::ltu_p (@1, TYPE_PRECISION (type)).
Ok with these changes.
Thanks,
Richard.
>
> Please review and let me know if its okay.
>
> Regression tested on AARH64 and x86_64.
>
> Thanks,
> Naveen
>
> 2015-09-01 Naveen H.S <[email protected]>
>
> gcc/ChangeLog:
>
> PR middle-end/67351
> * fold-const.c (fold_binary_loc) : Move
> Transform (x >> c) << c into x & (-1<<c) or
> transform (x << c) >> c into x & ((unsigned)-1 >> c) for unsigned
> types using simplify and match.
> * match.pd (lshift (rshift @0 INTEGER_CST@1) @1) : New simplifier.
> (rshift (lshift @0 INTEGER_CST@1) @1) : New Simplifier.
>
> gcc/testsuite/ChangeLog:
>
> PR middle-end/67351
> * g++.dg/pr66752-2.C: New test.
