This implementation was removed by 8b8af6d3 ("gallium/util: Switch
util_float_to_half to _mesa_float_to_half()'s impl.")
It was not actually broken, but _mesa_float_to_half() implements
round-to-nearest-even, whereas util_float_to_half() implemented
round-to-zero. So rename it appropriately.
GL actually never cares about rounding (except a broken piglit test),
however d3d10 very much does and requires RTZ for float to half
conversion. Moreover, apparently at least radeon gpus actually always
do RTZ when doing RT writes (and I'd suspect for shader image writes
as well). Hence it seems appropriate to hook up this rtz function to
the format instead. This will cause llvmpipe and softpipe to use rtz
rounding for clears with half float formats, and softpipe would use rtz
behavior for rt writes as well (llvmpipe has that hardcoded), not sure
if "real" hw drivers hit this function for much.
(For shader opcodes would still need to figure out what rounding to use
appropriately, but this is a question for another day.)
Note should probably unify with _mesa_float_to_float16_rtz. Unclear at
this point which one is better, so just restore previous function here.
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4312>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4312>
This reverts the functional part of commit
d17ff2f7f1, leaving the unit test for
mesa/pipe agreement on what's an array.
The issue is that the util_channel_desc.shift values on array formats are
not used for bit addressing in memory, they're bit addressing within a
word treating a pixel of the format as a native type, as seen by
llvmpipe's use of the values to do shifts (see
lp_build_unpack_arith_rgba_aos() for example). This means the values are
nonsensical for 3-byte RGB, but then llvmpipe doesn't expose those formats
so it works out.
I still want to clean up our big-endian format handling at some point, but
let's fix the s390x regression first, sort out our format unit tests in
CI, then be able to refactor with confidence.
Fixes: d17ff2f7f1 ("gallium: Fix big-endian addressing of non-bitmask array formats.")
Closes: #2472
Acked-by: Marek Olšák <marek.olsak@amd.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3721>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3721>
Eric recently added PIPE_FORMAT_FXT1_RGB[A] as part of his format
unification work. This was really most of the work of implementing
the extension. We just need to handle it in a couple of places and
expose the extension.
v2: Reject the new formats in llvmpipe_is_format_supported to prevent
crashes because it doesn't know how to handle the new formats.
Reviewed-by: Marek Olšák <marek.olsak@amd.com> [v1]
Reviewed-by: Eric Anholt <eric@anholt.net> [v1]
To make PIPE_FORMATs usable from non-gallium parts of Mesa, I want to
move their helpers out of gallium. Since u_format used
util_copy_rect(), I moved that in there, too.
I've put it in a separate directory in util/ because it's a big chunk
of related code, and it's not clear to me whether we might want it as
a separate library from libmesa_util at some point.
Closes: #1905
Acked-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
