On Thu, Mar 08, 2018 at 10:25:45PM +0000, Christos Zoulas wrote: > In article <20180308215453.gb22...@britannica.bec.de>, > Joerg Sonnenberger <jo...@bec.de> wrote: > >On Thu, Mar 08, 2018 at 03:32:33PM -0500, Christos Zoulas wrote: > >> Module Name: src > >> Committed By: christos > >> Date: Thu Mar 8 20:32:33 UTC 2018 > >> > >> Modified Files: > >> src/sys/sys: bitops.h > >> > >> Log Message: > >> PR/53081: Fix size of the shift to depend on the type of the bitmap so that > >> we get the correct width. > > > >Please don't use __typeof__. 1ull is good enough and we can depend on > >a non-stupid compiler to truncate the intermediate. > > The __typeof__ ship has already sailed: > > $ fgrep -r __typeof__ /usr/include/sys/ | wc -l > 3
Of those, only the rounddown2 is non-optional. That falls into the same category even, it doesn't really hurt to widen there. > Doing a 64 bit calculation on a 32 bit platform when it is not needed > is a waste (and produces narrowing warnings). It's not a 64bit calculation if the compiler is at least trying to create sane code. The bit masking should ensure that. Joerg
