[webkit-dev] Fix for Vector::m_inlineBuffer alignment?
ppedriana at gmail.com
Thu Sep 4 02:24:10 PDT 2008
This is a hardware issue and can vary between different versions. Some
hardware of course generates an unhandled exception on unaligned access;
some hardware generates an internally handled exception and restarts the
access with a different and more expensive pathway or with microcode;
some hardware efficiently handles it as it goes and has minimal impact.
Sometimes this behavior is different depending on whether the hardware
is in big endian vs. little endian mode. A new generation of the same
processor family or a version by a different company may act differently
than another. Finally, if that memory is accessed by a different means
than the CPU (e.g. via DMA or the video bus), then it may require
alignment where it doesn't otherwise.
What I'm getting at here is that I think we would need to be careful
about disabling it for any hardware, including even forgiving hardware
> On Sep 4, 2008, at 12:20 PM, Paul Pedriana wrote:
>> I'll make a patch and attach it to
>> <https://bugs.webkit.org/show_bug.cgi?id=16925>, if that's OK.
> That would be great!
> One thing I'm not sure about is whether we want to enforce alignment
> on platforms that don't require it - performance testing should answer
> - WBR, Alexey Proskuryakov
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