[Mesa-dev] [Bug 100613] Regression in Mesa 17 on s390x (zSystems)

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=100613

--- Comment #21 from Ray Strode [halfline] <rstrode at redhat.com> ---
Unless I'm misunderstanding something, I think this comment in u_format.h is
the crux of the issue:

    * If each channel is accessed as an individual N-byte value, X is always•
    * at the lowest address in memory, Y is always next, and so on.  For all•
    * currently-defined formats, the N-byte value has native endianness.•
    *•
    * If instead a group of channels is accessed as a single N-byte value,•
    * the order of the channels within that value depends on endianness.•
    * For big-endian targets, X is the most significant subvalue,•
    * otherwise it is the least significant one.•
    *•

I guess vector fetch is the first paragraph, and scalar fetch is the second
paragraph.  So they can't behave the same on big endian unless we introduce
swaps.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20170504/53b9914b/attachment.html>