For m32c chips, The address space is a flat 24-bit address space.
Address registers are 24 bits (i.e. they cannot hold an SImode) but
size_t is 16 bits originally because there aren't enough 24-bit math
ops and 32-bit math is too expensive. I've tried to use PSImode for
size_t recently (different
On 04/28/2013 11:13 PM, DJ Delorie wrote:
>
>> I have patches to let one specify a precision for partial int types,
>> easy enough to do, and the rest of the compiler plays nicely for the
>> most part with it...
>
> If you can make size_t truly be a 24-bit value, I'd be very happy :-)
This confu
> I have patches to let one specify a precision for partial int types,
> easy enough to do, and the rest of the compiler plays nicely for the
> most part with it...
If you can make size_t truly be a 24-bit value, I'd be very happy :-)
On Apr 26, 2013, at 4:05 AM, Bernd Schmidt wrote:
> On 04/24/2013 09:14 PM, DJ Delorie wrote:
>>> 24 bits stored as three bytes, or four? How does this affect vtable
>>> layout? I would have expected the C++ frontend and libsupc++ to
>>> currently be inconsistent with each other given such a setup
On 04/24/2013 09:14 PM, DJ Delorie wrote:
>> 24 bits stored as three bytes, or four? How does this affect vtable
>> layout? I would have expected the C++ frontend and libsupc++ to
>> currently be inconsistent with each other given such a setup.
>
> In memory, four, I think. The address registers
> 24 bits stored as three bytes, or four? How does this affect vtable
> layout? I would have expected the C++ frontend and libsupc++ to
> currently be inconsistent with each other given such a setup.
In memory, four, I think. The address registers really are three
bytes though. They're PSImode
On 04/24/2013 05:10 PM, DJ Delorie wrote:
>
>> this isn't true, it would be helpful to know. Given the size_t/uintptr_t
>> testsuite patch I just submitted I'm thinking they don't exist, but I'm
>> kind of wondering about m32c, so Cc'ing DJ.
>
> For m32c-elf with -mcpu=m32c, size_t is 16 bits but
> this isn't true, it would be helpful to know. Given the size_t/uintptr_t
> testsuite patch I just submitted I'm thinking they don't exist, but I'm
> kind of wondering about m32c, so Cc'ing DJ.
For m32c-elf with -mcpu=m32c, size_t is 16 bits but void* is 24 bits.
This is a patch series that changes the way vtables are constructed in
the C++ frontend (the first two are small preliminary patches, the meat
will be in 3/3). The problem I was trying to solve was that on the port
I was working on, function pointers are smaller than data pointers, and
size_t is sm
