[Bug middle-end/79665] gcc's signed (x*x)/200 is slower than clang's

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79665

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |jakub at gcc dot gnu.org

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
What we can do IMHO is in expand_divmod, if we have division or modulo by
constant and the first operand is known to have 0 MSB (from get_range_info or
get_nonzero_bits), then we can expand it as both signed or unsigned
division/modulo, regardless what unsignedp is.  Then we could compare costs of
both expansions and decide what is faster.