llvmpipe: add EXT_packed_float render target format support

New conversion code to handle conversion from/to r11g11b10 AoS to/from
SoA floats, and also add code for conversion from rgb9e5 AoS to float SoA
(which works pretty much the same as r11g11b10 except for the packing).
(This code should also be used for texture sampling instead of
relying on u_format conversion but it's not yet, so rgb9e5 is unused.)
Unfortunately a crazy amount of hacks is necessary to get the conversion
code running in llvmpipe's generate_unswizzled_blend, which isn't well
suited for formats where the storage representation has nothing to do
with what's needed for blending (moreover, the conversion will convert
from packed AoS values, which is the storage format, to float SoA values,
because this is much more natural for the conversion, and likewise from
SoA values to packed AoS values - but the "blend" (which includes
trivial things like partial mask) works on AoS values, so incoming fs
values will go SoA->AoS, values from destination will go packed
AoS->SoA->AoS, then do blend, then AoS->SoA->packed AoS which probably
isn't the most efficient way though the shuffles are probably bearable).

Passes piglit fbo-blending-formats (with GL_EXT_packed_float parameter),
still need to verify Inf/NaNs (where most of the complexity in the
conversion comes from actually).

v2: drop the (very bogus) rgb9e5 part, and do component extraction
in the helper code for r11g11b10 to float conversion, making the code
slightly more compact (suggested by Jose), now that there are no other
callers left this works quite well. (Could do the same for the
opposite way but it's less than ideal there, final part of packing
needs to be done in caller anyway and there'd be another conditional.)

v3: minor style and comment fixes. Also fix a potential issue with
negative zero being potentially returned by max(src, zero) as we
don't have well-defined min/max behavior (fortunately no additonal cost).

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
mesa: handle HALF_FLOAT like FLOAT in get_tex_rgba

NOTE: This is a candidate for the stable branches.

Reviewed-by: Brian Paul <brianp@vmware.com>
Tested-by: Brian Paul <brianp@vmware.com>
mesa: add a common function returning transfer ops for ReadPixels

I'll need both new functions for later. For now, it consolidates the code
for determining what the transfer ops should be and makes it a little bit
smarter.

v2: added "const"

Reviewed-by: Brian Paul <brianp@vmware.com>
Tested-by: Brian Paul <brianp@vmware.com>
mesa: add helper func for checking combined depthstencil buffers from st/mesa

Reviewed-by: Brian Paul <brianp@vmware.com>
Tested-by: Brian Paul <brianp@vmware.com>
mesa: add common format-independent memcpy-based ReadPixels path

I'll need the _mesa_readpixels_needs_slow_path function for the blit-based
version, but it's also useful to have this memcpy-based path in one place
and not scattered across several functions.

v2: add "const" to function parameters

Reviewed-by: Brian Paul <brianp@vmware.com>
Tested-by: Brian Paul <brianp@vmware.com>
st/mesa: implement blit-based ReadPixels

Initial version contributed by: Martin Andersson <g02maran@gmail.com>

This is only used if the memcpy path cannot be used and if no transfer ops
are needed. It's pretty similar to our TexImage and GetTexImage
implementations.

The motivation behind this is to be able to use ReadPixels every frame and
still have at least 20 fps (or 60 fps with a powerful GPU and CPU)
instead of 0.5 fps.

Reviewed-by: Brian Paul <brianp@vmware.com>
Tested-by: Brian Paul <brianp@vmware.com>
gallium,st/mesa: don't use blit-based transfers with software rasterizers

The blit-based paths for TexImage, GetTexImage, and ReadPixels aren't very
fast with software rasterizer. Now Gallium drivers have the ability to turn
them off.

Reviewed-by: Brian Paul <brianp@vmware.com>
Tested-by: Brian Paul <brianp@vmware.com>
gallivm: Add code for rgb9e5 shared exponent format to float conversion

And use this (and the code for r11g11b10 packed float to float conversion)
in the soa texturing code (the generated code looks quite good).
Should be an order of magnitude faster probably than using the fallback
(not measured).
Tested with piglit texwrap GL_EXT_packed_float and
GL_EXT_texture_shared_exponent respectively (didn't find much else using
it).

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
clover: add dynamic_cast results checking down in clSetKernelArgument() code path.

Signed-off-by: Dmitry Cherkassov <dcherkassov@gmail.com>
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
mesa: allow internalformat_query with multisample texture targets

Now that we support ARB_texture_multisample, there are multiple targets
accepted for this query, and they may have target-dependent limits, so
pass the target to the driverfunc.

For example, the sampling hardware may not be able to do general
texelFetch() for some format/sample count combination, but the driver
may still be able to implement a reasonable resolve operation, so it can
be supported for renderbuffers.

V2: - Don't break Gallium compile.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
mesa: helper for checking renderbuffer sample count

Pulls the checking of the sample count into a helper function, and
extends the existing logic to include the interactions with both
ARB_texture_multisample and ARB_internalformat_query.

_mesa_check_sample_count() checks a desired sample count against a
a combination of target/internalformat, and returns the error enum
to be produced, if any. Unfortunately the conditions are messy and the
errors vary.

V2: - Tidy up spurious block.
    - Move _mesa_check_sample_count() to multisample.c instead; It
      doesn't really belong in fbobject.c or teximage.c.
    - Inlined spec quotes

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
mesa: use _mesa_check_sample_count() for multisample textures

Extends _mesa_check_sample_count() to properly support the
TEXTURE_2D_MULTISAMPLE and TEXTURE_2D_MULTISAMPLE_ARRAY targets, which
have subtly different limits than renderbuffers.

This resolves the remaining TODO in the implementation of
TexImage*DMultisample.

V2: - Don't introduce spurious block.
    - Do this in multisample.c instead.
    - Fix typo in error message.
    - Inline spec quotes

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
i965: bump MAX_DEPTH_TEXTURE_SAMPLES to 4/8

Bump MAX_DEPTH_TEXTURE_SAMPLES to match what GetInternalformativ is
claiming. Since that limit is what is actually enforced now, this
doesn't actually change anything except the queried value.

There's still no piglits verifying that multisample depth textures work,
but this works in the Unigine demos.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
i965/gen7: Use WE_all mode when enabling channel masks for URB write.

Gen7 adds mask bits to the message header for a URB write which allow
the write to apply only to certain channels.  We don't use this
functionality, so to ensure that the entire write always occurs, we
emit an OR instruction to set the mask bits.

With the advent of geometry shaders, URB writes won't just happen at
the end of a thread; they will happen in mid-thread too.  Thus, we can
no longer rely on channel 0 being enabled, so we need to emit the OR
instruction in WE_all mode to ensure that it is executed.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
i965: Clarify nomenclature: vert_result -> varying

This patch removes the terminology "vert_result" from the i965 driver,
replacing it with "varying".  The old terminology, "vert_result", was
confusing because (a) it referred to the enum gl_vert_result, which no
longer exists (it was replaced with gl_varying_slot), and (b) it
implied a vertex output, but with the advent of geometry shaders, it
could be either a vertex or a geometry output, depending what shaders
are in use.  The generic term "varying" is less confusing.

No functional change.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

v2: Whitespace fixes.
i965: Move brw_vs_prog_data::outputs_written into VUE map.

Future patches will allow for there to be separate VUE maps when both
a geometry shader and a vertex shader are in use.  When this happens,
we will want to have correspondingly separate outputs_written
bitfields.  Moving outputs_written into the VUE map will make this
easy.

For consistency with the terminology used in the VUE map, the bitfield
is renamed to "slots_valid" in the process.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
i965: Store the geometry output VUE map in brw_context.

Currently, the GPU pipeline has one active VUE map in effect at any
given time--the one representing the layout of vertex data coming from
the vertex shader.  However, when geometry shaders are added, they
will have their own independent VUE map.  Later pipeline stages (clip,
sf, fs) will need to consult the geometry shader VUE map if a geometry
shader is in use, and the vertex shader VUE map otherwise.

This patch adds a new field to brw_context, vue_map_geom_out, which
contains the VUE map that should be used by later pipeline stages.  It
also adds a new state flag, BRW_NEW_VUE_MAP_GEOM_OUT, which is
signalled whenever the contents of the VUE map changes.

Since we don't support geometry shaders yet, vue_map_geom_out is
currently set only by the brw_vs_prog state atom.

v2: Don't set vue_map_geom_out in do_vs_prog--that's redundant and
possibly problematic for precompiles.  Only set it in
brw_upload_vs_prog.  Also, make a copy instead of using a
pointer--this makes it possible to detect when the VUE map hasn't
changed, so we can avoid redundant state uploads.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
i965: Use brw.vue_map_geom_out instead of VS output VUE map where appropriate.

This patch modifies post-GS pipeline stages (transform feedback, clip,
sf, fs) to refer to the VUE map through brw->vue_map_geom_out rather
than brw->vs.prog_data->vue_map.  This ensures that when geometry
shader support is added, these pipeline stages will consult the
geometry shader output VUE map when appropriate, rather than the
vertex shader output VUE map.

v2: Fixed some stale "CACHE_NEW_VS_PROG" comments.
i965/fs: Rename vp_outputs_written to input_slots_valid.

With the introduction of geometry shaders, fragment inputs will no
longer come exclusively from the vertex shader; sometimes they come
from the geometry shader.  So the name "vp_outputs_written" will
become a misnomer.  This patch renames vp_outputs_written to
input_slots_valid, to reflect the true meaning of the bitfield from
the fragment shader's point of view: it indicates which of the
possible input slots contain valid data that was written by the
previous shader stage.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
i965: Shrink brw_vue_map struct.

This patch changes the arrays in brw_vue_map (which only ever contain
values from -1 to 58) from ints to signed chars.  This reduces the
size of the struct from 488 bytes to 136 bytes.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>