[Bug tree-optimization/96542] Failure to optimize simple code to a constant when storing part of the operation in a variable

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96542

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Andrew Macleod <amacl...@gcc.gnu.org>:

https://gcc.gnu.org/g:704e8a825c78b9a8424c291509413bbb48e602c7

commit r12-2381-g704e8a825c78b9a8424c291509413bbb48e602c7
Author: Andrew MacLeod <amacl...@redhat.com>
Date:   Fri Jul 16 11:42:14 2021 -0400

    Add wi_fold_in_parts.

    range-ops uses wi_fold to individually fold subranges one at a time and
    then combined them.  This patch first calls wi_fold_in_parts which checks
if
    one of the subranges is small, and if so, further splits that subrange
    into constants.

            gcc/
            PR tree-optimization/96542
            * range-op.cc (range_operator::wi_fold_in_parts): New.
            (range_operator::fold_range): Call wi_fold_in_parts.
            (operator_lshift::wi_fold): Fix broken lshift by [0,0].
            * range-op.h (wi_fold_in_parts): Add prototype.

            gcc/testsuite
            * gcc.dg/pr96542.c: New.