This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [RFC] Changes to the wide-int classes

On 09/02/2013 05:35 AM, Richard Biener wrote:
On Mon, 2 Sep 2013, Richard Sandiford wrote:

Kenneth Zadeck <> writes:
There is no place for exactly two HWIs in the machine independent parts
of the compiler,
I totally agree.  In fact I was taking that so much for granted that
I didn't even think to add a rider about it, sorry.  I didn't mean
to imply that we should keep double_int around.

I think the reason for doing this is to prove that it can be done
(so that the wide_int code isn't too big a change for the tree level)
and to make it easier to merge the wide-int patches into trunk piecemeal
if we need to.
Note that changing the tree rep to non-double_int is easy.  Also note
that I only want 'double_int' to stay around to have a fast type
that can work on two HWIs for the code that need more precision
than a HWI.  The only important cases I know of are in
get_inner_reference and get_ref_base_and_extent and friends.  Those
are heavily used (and the only double-int function callers that
even show up in regular cc1 profiles).

So if wide_int_fixed<2> ('2' better be replaced with
works for those cases then fine (and we can drop double-ints).
This is what the addr_wide_int is for - it sniffs the port and is guaranteed to big enough to hold the largest pointer, + 4 bits (3 bits for bitposition and 1 bit so that unsigned things come over with no loss) then that is rounded up to the next hwi. (i will admit that the sniffing code needs a little work but that can be fixed without changing the api).


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]