Commit 1ed8d907b3998b847daa26154ca0261f55f0de23 inadvertently dropped
emitting the tessellator domain for domain shaders. Although Vulkan
environments allow us to write the tessellator domain from the hull
shader, the domain shader, or both, that's not generally true for OpenGL
environments.
We're explicitly replacing zero with one in the only place where the
plane count being zero or one makes a difference. It also make sense:
UNKNOWN is used for buffers, which for all intents and purposes have one
plane.
Uncovered by the ininf() test in the next commit. This is why we insist
on test coverage; unfortunately this one slipped through in
fd1beedc07becc7e5e49b64273f7bde7f9a8b2a0.
Vertex shaders do not have CMP, so we use SLT and MAD.
For example, this vertex shader:
uniform float4 f;
void main(inout float4 pos : position, out float4 t1 : TEXCOORD1)
{
t1 = (int4)f;
}
results in:
vs_2_0
dcl_position v0
slt r0, c0, -c0
frc r1, c0
add r2, -r1, c0
slt r1, -r1, r1
mad oT1, r0, r1, r2
mov oPos, v0
while we have the lower_cmp() pass, each time it is applied many
instructions are generated, so this patch introduces a specialized
version of the cast-to-int lowering for efficiency.
