It was not taken into account that without Offset decoration
the output is not written into XFB.
Aside from eliminating more outputs this change prevents gl_PerVertex
builtins generated by glslang from being kept alive in case when XFB
is enabled. Keeping such outputs alive may upset a driver.
VUID-StandaloneSpirv-Offset-04716:
"Only variables or block members in the output interface decorated
with Offset can be captured for transform feedback, and those
variables or block members must also be decorated with XfbBuffer
and XfbStride, or inherit XfbBuffer and XfbStride decorations from
a block containing them"
Additional info about glslang behavior could be found at:
https://github.com/KhronosGroup/glslang/issues/1526
Signed-off-by: Danylo Piliaiev <dpiliaiev@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24318>
This encapsulates all the little bits needed to turn a shader module
into some mostly reasonable NIR. It handles inlining functions,
lowering variable initializers, handling per-member structs and other
trickiness that is needed for consuming the output of spirv_to_nir.
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15305>
