PATCH: Enable TFmode for SSE2

[Richard Guenther]

On Sun, Jun 29, 2008 at 10:24 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
> Richard Guenther wrote:
>
>>> You can create a TImode/TFmode sign bitmask via CONST_VECTOR, just look
>>> at
>>> ix86_build_const_vector for an example. TFmode mask is currently created
>>> as
>>> CONST_DOUBLE just because 128bit modes were enabled for 64bit targets
>>> only
>>> and this was the simplest way ;)
>>>
>>> And we will again avoid 64bit HWI.
>>>
>>
>> Why not simply use 64bit HWI on i?86?
>>
>
> I'm worried a bit about compile times on 32bit hosts. Please note that not
> everybody has 2^N-core 64bit gear to play with. OTOH, I don't recall if
> anybody measured bootstrap time with 64bit HWI on 32bit target yet. This is
> the data we need to consider before enabling 64bit HWI.
>
> Also note, that 128bit constants can be decomposed to a const vector and
> loaded from memory as CONST_VECTOR.

Some distributors enable 64bit HWI on i686 to be able to enable 64bit
mutlilib there.  Debian for example does this.  ISTR x86-darwin also does it,
but I am not sure.  (no, SUSE doesn't do it (yet))

Richard.