gallivm: some bits of seamless cube filtering implementation

Simply adjust wrap mode to clamp_to_edge. This is all that's needed for a
correct implementation for nearest filtering, and it's way better than
using repeat wrap for instance for linear filtering (though obviously this
doesn't actually do seamless filtering).

v2: fix s/t wrap not r/s...

Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
i965/gs: Add new primitive types.

As part of its support for geometry shaders, GL 3.2 introduces four
new primitive types: GL_LINES_ADJACENCY, GL_LINE_STRIP_ADJACENCY,
GL_TRIANGLES_ADJACENCY, and GL_TRIANGLE_STRIP_ADJACENCY.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
i965/gs: New gs primitive types are supported by HW primitive restart.

When we previously implemented primitive restart, we didn't add cases
to brw_primitive_restart.c's can_cut_index_handle_prims() for the
primitive types that are introduced with geometry shaders.  It turns
out that all of the new primitive types are supported by hardware
primitive restart.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
i965/gs: Implement basic gl_PrimitiveIDIn functionality.

If the geometry shader refers to the built-in variable
gl_PrimitiveIDIn, we need to set a bit in 3DSTATE_GS to tell the
hardware to dispatch primitive ID to r1, and we need to leave room for
it when allocating registers.

Note: this feature doesn't yet work properly when software primitive
restart is in use (the primitive ID counter will incorrectly reset
with each primitive restart, since software primitive restart works by
performing multiple draw calls).  I plan to address that in a future
patch series.

Fixes piglit test "spec/glsl-1.50/execution/geometry/primitive-id-in".

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
i965: Add some missing bits to {mesa,brw,cache}_bits[].

These data structures are used for debug output, so it wasn't hurting
anything that there were missing bits.  But it's good to keep things
up to date.

This patch also adds static asserts so that the {brw,cache}_bits[]
arrays are the proper size, so that we don't forget to add to them in
the future.  Unfortunately there's no convenient way to assert that
mesa_bits[] is the proper size.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
glsl: Keep track of location for interface block fields.

This patch adds a "location" element to struct glsl_struct_field, so
that we can keep track of the gl_varying_slot associated with each
built-in geometry shader input.

In lower_named_interface_blocks, we use this value to populate the
"location" field in the ir_variable that stores each geometry shader
input.
glsl/gs: add gl_in support to builtin_variables.cpp.

Previously, builtin_variables.cpp was written assuming that we
supported ARB_geometry_shader4 style geometry shader inputs, meaning
that each built-in varying input to a geometry was supplied via an
array variable whose name ended in "In", e.g. gl_PositionIn or
gl_PointSizeIn.

However, in GLSL 1.50 style geometry shaders, things work
differently--built-in inputs are supplied to geometry shaders via a
built-in interface block called gl_in, which contains all the built-in
inputs using their usual names (e.g. the gl_Position input is supplied
to the geometry shader as gl_in[i].gl_Position).

This patch adds the necessary logic to builtin_variables.cpp to create
the gl_in interface block and populate it accordingly for geometry
shader inputs.  The old ARB_geometry_shader4 style varyings are
removed, though they can easily be added back in the future if we
decide to support ARB_geometry_shader4.
glsl/gs: handle gl_ClipDistance geometry input in lower_clip_distance.

This corresponds to the lowering of gl_ClipDistance to
gl_ClipDistanceMESA for vertex and geometry shader outputs.  Since
this lowering pass occurs after lower_named_interface blocks, it deals
with 2D arrays (gl_ClipDistance[vertex][clip_plane]) rather than 1D
arrays in an interface block
(gl_in[vertex].gl_ClipDistance[clip_plane]).

v2 (Paul Berry <stereotype441@gmail.com>): Fix indexing order for
gl_ClipDistance input lowering.  Properly lower bulk assignment of
gl_ClipDistance inputs.  Rework for GLSL 1.50 style geometry shaders.
i965/gs: Fixup gl_PointSize on entry to geometry shaders.

gl_PointSize is stored in the w component of VARYING_SLOT_PSIZ, but
the geometry shader infrastructure assumes that it should look for all
geometry shader inputs of type float in the x component.  So when
compiling a geomtery shader that uses a gl_PointSize input, fix it up
during the shader prolog by moving the w component to the x component.

This is similar to how we emit fixups and workarounds for vertex
shader attributes.

Fixes piglit test spec/glsl-1.50/execution/geometry/core-inputs.
!UPSTREAM: i965/gs: Generalize some error messages for GS.

TODO: find more places to generalize.
TODO: Don't use "VS/GS" terminology.  Use "vec4" terminology, since that will endure longer.
!UPSTREAM: glsl: Add new geometry shader constants.

TOOD:
- These constants need to be plumbed through to the driver back-ends.
main: Expose geometry shader constants in GL 3.0.
!UPSTREAM: mesa: fix transform feedback when a geometry shader is active.

TODO: test
!UPSTREAM: glsl/linker: Fail if linking geometry shader with 0 GEOMETRY_VERTICES_OUT.

ARB_geometry_shader4 spec 2.15.2:
"Linking will also fail [...] if the program object contains objects to form a
geometry shader, and the value of GEOMETRY_VERTICES_OUT_ARB is zero."

Reviewed-by: Paul Berry <stereotype441@gmail.com>

TODO: May not be necessary for GLSL 1.50 style geometry shaders.  Make a test to validate.
!UPSTREAM: i965: turn on GS.

TODO:
- Commit message
!UPSTREAM: Debug optimization passes.
!UPSTREAM: Expose GLSL 1.50 and GL 3.2 core contexts.

This lets me run tests normally, since globally doing GL version override
can break tests that require a compatibility context.
vbo: Make vbo_sw_primitive_restart optionally count primitives.

This will be necessary in order to get the i965 back-end to produce
the correct value of gl_PrimitiveIDIn when using software primitive
restart.
!UPSTREAM: i965/gs: Fix gl_PrimitiveIDIn when using SW primitive restart.

TODO: We really ought to set _NEW_PROGRAM_CONSTANTS only when software
primitive restart is in use.  Currently we set it for hardware
primitive restart too.
!UPSTREAM: i965/gs: Set the REORDER bit in 3DSTATE_GS.

Ivy Bridge's "reorder enable" bit gives us a binary choice for the
order in which vertices from triangle strips are delivered to the
geometry shader.  Neither choice follows the OpenGL spec, but setting
the bit is better, because it gets triangle orientation correct.

Haswell replaces the "reorder enable" bit with a new "reorder mode"
bit (which occupies the same location in the command packet).  This
bit gives us a different binary choice, which affects both triangle
strips and triangle strips with adjacency.  Setting the bit gives the
proper order according to the OpenGL spec.

So in either case we want to set the bit.

On Ivy Bridge, fixes piglit test
spec/glsl-1.50/execution/geometry/triangle-strip-orientation.

On Haswell, should fix piglit tests
spec/glsl-1.50/glsl-1.50-geometry-primitive-types
{GL_TRIANGLE_STRIP,GL_TRIANGLE_STRIP_ADJACENCY}, but I haven't tested
this.

TODO: test on HSW