Re: [webkit-dev] RFC: dropping support for x87

2019-03-21 Thread Xan
Since there were no negative comments in the list, just another extra
positive comment in the bug itself, we have landed this:
https://trac.webkit.org/changeset/243293/webkit

Xan

On Mon, Mar 11, 2019 at 7:00 PM Xan  wrote:

> Hi,
> as part of Igalia's work on 32bit support we spent some time trying to
> iron out some bugs in JSC/intel 32bit builds. A bunch of them were related
> to rounding errors (or more precisely, differences) caused by the extended
> precision FP registers used by default in x87; which, in turn, is the
> default in GCC when compiling with -m32.
>
> We discussed a number of solutions, but then we noticed that major
> browsers have in recent times already dropped support for x87:
>
> Firefox:
> https://support.mozilla.org/en-US/kb/your-hardware-no-longer-supported
> Chrome: https://support.google.com/chrome/a/answer/7100626?hl=en
>
> This removes a small maintenance burden and prevents future bugs like the
> ones we investigated. Also, in practice, intel hardware older than Pentium
> 4-era machines is very rare. All this considered, we decided it made sense
> to do the same in WebKit.
>
> In short, this email is a RFC to see if anyone in the WebKit community
> objects to this change, or has any comment about it. The bug where we have
> attached the patch for this change is:
> https://bugs.webkit.org/show_bug.cgi?id=194853
>
> Regards,
> Xan
>
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[webkit-dev] RFC: dropping support for x87

2019-03-11 Thread Xan
Hi,
as part of Igalia's work on 32bit support we spent some time trying to iron
out some bugs in JSC/intel 32bit builds. A bunch of them were related to
rounding errors (or more precisely, differences) caused by the extended
precision FP registers used by default in x87; which, in turn, is the
default in GCC when compiling with -m32.

We discussed a number of solutions, but then we noticed that major browsers
have in recent times already dropped support for x87:

Firefox:
https://support.mozilla.org/en-US/kb/your-hardware-no-longer-supported
Chrome: https://support.google.com/chrome/a/answer/7100626?hl=en

This removes a small maintenance burden and prevents future bugs like the
ones we investigated. Also, in practice, intel hardware older than Pentium
4-era machines is very rare. All this considered, we decided it made sense
to do the same in WebKit.

In short, this email is a RFC to see if anyone in the WebKit community
objects to this change, or has any comment about it. The bug where we have
attached the patch for this change is:
https://bugs.webkit.org/show_bug.cgi?id=194853

Regards,
Xan
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