Particularly constant colours, but also (more obscurely) SNORM.
Fixes arb_color_buffer_float-render with SNORM framebuffers. Issue affects both
Asahi and Panfrost (the latter after we start advertising EXT_render_snorm).
v2: Check the blend factor to avoid unnecessary clamps. This avoids regressing
blend shader code quality on Panfrost.
Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Reviewed-by: Gert Wollny <gert.wollny@collabora.com> [v1]
Acked-by: Emma Anholt <emma@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20016>
In this case we have 4 components but the value of the fourth component
is undefined. Apply the fixup we already have.
Fixes
dEQP-GLES3.functional.draw_buffers_indexed.random.max_implementation_draw_buffers.0
on Asahi. That test blend with DST_ALPHA with its RGB565 attachment,
which is fine if RGB565 is preserved, but Asahi is demoting that
format to RGBX8 which means -- after lowering the tilebuffer access --
we blend with an ssa_undef.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20016>
The option struct passed to nir_lower_blend doesn't have a "blending
disabled" flag. Unless blending is skipped due to logic ops or
framebuffer formats, nir_lower_blend always blends, even if the blend
mode is "replace" (corresponding to the API level blend disable).
That's mostly okay, since NIR can optimize out the code, at the expense
of a little compile time. However, there's a catch: nir_lower_blend
emits fsat at the start of the shader (for UNORM framebuffers, or
fsat_signed for SNORM). We can expect hardware to saturate the input to
store_output itself, so these operations are redundant, but it's tricky
to optimize these instructions out otherwise. Don't even try: detect the
replace blend mode and don't call nir_blend in that case. Colour masking
is still applied as usual.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Emma Anholt <emma@anholt.net>
Reviewed-by: Jason Ekstrand <jason.ekstrand@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18535>
Because we pull the RT from the variable location and use that to look
up formats, we need a constant RT index. To deal with arrays (possibly
of arrays), we would either need to handle array derefs (we don't today)
or we need to require the variables to be split into one variable per
RT. Given that we have to lower indirect derefs anyway (to get constant
indices), we may as well require the client to split output variables by
calling nir_lower_io_arrays_to_elements_no_indirect().
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16309>
The BITFIELD_MASK() macro is intended for using with actual bitfields,
not with nir_component_mask_t. This means we do some extra work to
handle values that are invalid for nir_component_mask_t in the first
place.
This eliminates some warnings on Clang, where the compiler complains
about casting UINT32_MAX to UINT16_MAX.
Reviewed-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15547>
nir_lower_blend was written against the OpenGL ES 3.2 specification,
which does not support blending SNORM render targets. The ES spec
says that non-floating point buffers get clamped to [0, 1] before
blending. The story is not so simple: SNORM buffers are blendable in
OpenGL and must clamped to [-1, 1] rather than [0, 1]. Handle this case.
NIR does have the fsat_signed_mali instruction to clamp to [-1, 1], but
it is only implemented in Panfrost, and this pass is in common code.
Open code it instead. Panfrost optimizes the open coded version, so this
is good enough.
Fixes SNORM subtests of Piglit arb_texture_view-rendering-formats.
Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13499>
Make sure the new and old sources have the same number of components,
otherwise the NIR validation pass complains.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13060>
SCALED formats are interpreted as floats, but not in the usual [0, 1]
or [-1, 1] range, meaning that the blend lowering logic can't directly
apply to those. Assert that the format being passed is not a scaled
format.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13060>
The caller doesn't necessarily want to lower blend operations on all
render targets since some of them might be supported natively (panvk
will be in that case). Let's just skip RTs that have a format set to
PIPE_FORMAT_NONE to allow that.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13060>
nir_ssa_for_src() is not supposed to pad the src vector if
dst->num_components > src->num_components. Let's pad things explicitly
with nir_pad_vector().
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13060>
This pass was originally developed for Panfrost, where it passes the
relevant dEQP tests. Upstreaming so it can be extended and then shared
with:
* Asahi, for blending
* Zink, for logic ops
* Lavapipe, for advanced blending
Note that using this with MRT in a fragment shader (as non-panfrost
drivers will) has not yet been tested. Logic ops with integer
framebuffers are probably todo. It's been enough for Panfrost, will
suffice for ES2 on Asahi, and provides an upstream base for kusma's work
on advanced blending, so overall the merge is a net benefit.
v2: Remove bogus assert that the format layout is PLAIN. We need to
render R11G11B10, which Mesa reports as layout OTHER. The code is still
correct.
Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com> [v1]
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10601>
