https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105119
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2022-11-28
Ever confirmed|0 |1
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The unsigned case is handled with r8-1550-g71f82be94fad15 .
The comment in match.pd is now:
/* (A / (1 << B)) -> (A >> B).
Only for unsigned A. For signed A, this would not preserve rounding
toward zero.
For example: (-1 / ( 1 << B)) != -1 >> B.
Also also [handle] widening conversions, like:
(A / (unsigned long long) (1U << B)) -> (A >> B)
or
(A / (unsigned long long) (1 << B)) -> (A >> B).
If the left shift is signed, it can be done only if the upper bits
of A starting from shift's type sign bit are zero, as
(unsigned long long) (1 << 31) is -2147483648ULL, not 2147483648ULL,
so it is valid only if A >> 31 is zero. */
Confirmed.
