Re: [PATCH][RFC][wide-int] Fix some build errors on arm in wide-int branch and report ICE

[Richard Biener <richard dot guenther at gmail dot com>]

On Wed, Apr 23, 2014 at 4:29 PM, Kenneth Zadeck
<zadeck@naturalbridge.com> wrote:
> On 04/23/2014 05:47 AM, Richard Biener wrote:
>>
>> On Tue, Apr 22, 2014 at 6:04 PM, Mike Stump <mikestump@comcast.net> wrote:
>>>
>>> On Apr 22, 2014, at 8:33 AM, Richard Sandiford
>>> <rdsandiford@googlemail.com> wrote:
>>>>
>>>> Kyrill Tkachov <kyrylo.tkachov@arm.com> writes:
>>>>>
>>>>> Ping.
>>>>> http://gcc.gnu.org/ml/gcc-patches/2014-04/msg00769.html
>>>>> Any ideas? I recall chatter on IRC that we want to merge wide-int into
>>>>> trunk
>>>>> soon. Bootstrap failure on arm would prevent that...
>>>>
>>>> Sorry for the late reply.  I hadn't forgotten, but I wanted to wait
>>>> until I had chance to look into the ICE before replying, which I haven't
>>>> had chance to do yet.
>>>
>>> They are separable issues, so, I checked in the change.
>>>
>>>> It's a shame we can't use C++ style casts,
>>>> but I suppose that's the price to pay for being able to write
>>>> "unsigned HOST_WIDE_INTâ.
>>>
>>> unsigned_HOST_WIDE_INT isnât horrible, but, yeah, my fingers were
>>> expecting a typedef or better.  I slightly prefer the int (1) style, but I
>>> think we should go the direction of the patch.
>>
>> Well, on my list of things to try for 4.10 is to kill off HOST_WIDE_* and
>> require a 64bit integer type on the host and force all targets to use
>> a 64bit 'hwi'.  Thus, s/HOST_WIDE_INT/int64_t/ (and the appropriate
>> related changes).
>>
>> Richard.
>
> I should point out that there is a community that wants to go in the
> opposite direction here.   They are the people with real 32 bit hosts who
> want to go back to a world where they are allowed to make hwi a 32 bit
> value.    They have been waiting wide-int to be committed because they see
> this as a way to get back to world where most of the math is done natively.
>
> I am not part of this community but they feel that if the math that has the
> potential to be big to be is done in wide-ints, then they can go back to
> using a 32 bit hwi for everything else.    For them, a wide-int built on 32
> hwi's would be a win.

That wide-int builds on HWI is an implementation detail.  It can easily
be changed to build on int32_t.

Btw, what important target still supports a 32bit HWI?  None for what
I know.  Look at config.gcc and what does _not_ set need_64bit_hwint.
Even plain arm needs it.

Richard.

> kenny