[Bug tree-optimization/91029] missed optimization regarding value of modulo operation

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91029

--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:d3f293348768667c07770e433ff00af51fee73a2

commit r11-5186-gd3f293348768667c07770e433ff00af51fee73a2
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Fri Nov 20 00:02:21 2020 +0100

    ranger: Improve a % b operand ranges [PR91029]

    As mentioned in the PR, the previous PR91029 patch was testing
    op2 >= 0 which is unnecessary, even negative op2 values will work the same,
    furthermore, from if a % b > 0 we can deduce a > 0 rather than just a >= 0
    (0 % b would be 0), and it actually valid even for other constants than 0,
    a % b > 5 means a > 5 (a % b has the same sign as a and a in [0, 5] would
    result in a % b in [0, 5].  Also, we can deduce a range for the other
    operand, if we know
    a % b >= 20, then b must be (in absolute value for signed modulo) > 20,
    for a % [0, 20] the result would be [0, 19].

    2020-11-19  Jakub Jelinek  <jakub@redhat.com>

            PR tree-optimization/91029
            * range-op.cc (operator_trunc_mod::op1_range): Don't require signed
            types, nor require that op2 >= 0.  Implement (a % b) >= x && x > 0
            implies a >= x and (a % b) <= x && x < 0 implies a <= x.
            (operator_trunc_mod::op2_range): New method.

            * gcc.dg/tree-ssa/pr91029-1.c: New test.
            * gcc.dg/tree-ssa/pr91029-2.c: New test.