Now, instead of a magic write register for VPM stores we have an
instruction to do them (which means no packing of other ALU ops into it),
with the ability to reorder the VPM stores due to the offset being baked
into the instruction.
VPM loads also gain the ability to be reordered by packing the row into
the A argument. They also no longer write to the r3 accumulator, and
instead must be stored to a physical register.
The WRTMUC replaces the implicit uniform loads in the first two texture
instructions. LDVPM disappears in favor of an ALU op. LDVARY, LDTMU,
LDTLB, and LDUNIF*RF now write to arbitrary registers, which required
passing the devinfo through to a few more functions.
This means that with no flatshading we'll emit the single-byte
ZERO_ALL_FLAT_SHADE_FLAGS, and otherwise emit a set of FLAT_SHADE_FLAGS to
get all the bits we need set.
There's a _SET enum in the packet we could use to possibly set entire
ranges of the bitfield without using another packet, but this at least
fixes the conformance failure.
In updating the simulator, behavior changed slightly so that our old code
wasn't getting glxgears's flatshading interpolated right. Emit flat
shading code just like we would for a normal flat-shaded varying, by
passing a flag in the shader key for glShadeModel(GL_FLAT) state and
customizing the color inputs based on that.
The compiler decides how many LDTMUs we're going to emit, and that must
match the P1 flags. This brings the return channel counting to a single
place (so all that's passed into the compiler is "how many return channels
you may request from this texture's format), and was a necessary step for
shadow samplers once we stop using OVRTMUOUT=0.
The HW has no native sampler support for multisample textures, but since
we only need to support txf_ms and the layout is UIF, we just need to
scale up the texcoords and then add in the sample.
This drops the old TEXTURE_MSAA_ADDR special uniform, since we're treating
MSAA textures as textures, rather than basically texbos like VC4 had to.
I already had the texture's wrapping set up to use different behavior for
nearest or linear, so we just needed to saturate the coordinates in linear
mode to get the "proper" blend between the edge and border values.
A bit of spec text suggested that (like vc4) condition codes should be
used for discards, and the simulator was fine with it, but the 7268
disagrees and you have to use SETMSF instead or the color comes through.
Fixes glsl-fs-discard-01 and many of the interpolation-with-clipping
tests.
In order to keep early-Z from writing early in a discard shader, you need
to set the "modifies Z" bit in the shader state (which the new
prog_data.discards will indicate). Then, in the shader we do a TLB write
to make Z passthrough happen (the QPU result is ignored, so we use a NULL
source).
This is a pretty straightforward fork of VC4's NIR compiler to VC5. The
condition codes, registers, and I/O have all changed, making the backend
hard to share, though their heritage is still recognizable.
v2: Move to src/broadcom/compiler to match intel's layout, rename more
"vc5" to "v3d", rename QIR to VIR ("V3D IR") to avoid symbol conflicts
with vc4, use new v3d_debug header, add compiler init/free functions,
do texture swizzling in NIR to allow optimization.
