When Connor originally drafted NIR, he copied the same function+overload
system that GLSL IR had with a few names changed. However, this
double-indirection is not really needed and has only served to confuse
people. Instead, let's just have functions which may not have unique names
and may or may not have an implementation. If someone wants to do overload
resolving, they can hav a hash table based function+overload system in the
overload resolving pass. There's no good reason to keep it in core NIR.
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Acked-by: Kenneth Graunke <kenneth@whitecape.org>
ir3 bits are
Reviewed-by: Rob Clark <robclark@gmail.com>
Tessellation control shaders need to be careful when writing outputs.
Because multiple threads can concurrently write the same output
variables, we need to only write the exact components we were told.
Traditionally, for sub-vector writes, we've read the whole vector,
updated the temporary, and written the whole vector back. This breaks
down with concurrent access.
This patch prepares the way for a solution by adding a writemask field
to store_var intrinsics, as well as the other store intrinsics. It then
updates all produces to emit a writemask of "all channels enabled". It
updates nir_lower_io to copy the writemask to output store intrinsics.
Finally, it updates nir_lower_vars_to_ssa to handle partial writemasks
by doing a read-modify-write cycle (which is safe, because local
variables are specific to a single thread).
This should have no functional change, since no one actually emits
partial writemasks yet.
v2: Make nir_validate momentarily assert that writemasks cover the
complete value - we shouldn't have partial writemasks yet
(requested by Jason Ekstrand).
v3: Fix accidental SSBO change that arose from merge conflicts.
v4: Don't try to handle writemasks in ir3_compiler_nir - my code
for indirects was likely wrong, and TTN doesn't generate partial
writemasks today anyway. Change them to asserts as requested by
Rob Clark.
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com> [v3]
Previously, this function returned the number of elements for structures
and arrays and 0 for everything else. In NIR, this is almost never what
you want because we also treat matricies as arrays so you have to
special-case constantly. This commit glsl_get_length treat matrices
as an array of columns by returning the number of columns instead of 0
This also fixes a bug in locals_to_regs caused by not checking for the
matrix case in one place.
v2: Only special-case for matrices and return a length of 0 for vectors as
we did before. This was needed to not break the TGSI-based drivers and
doesn't really affect NIR at the moment.
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Tested-by: Rob Clark <robclark@freedesktop.org>
Jason pointed out that variable dereferences in NIR are really part of
their parent instruction, and should have the same lifetime.
Unlike in GLSL IR, they're not used very often - just for intrinsic
variables, call parameters & return, and indirect samplers for
texturing. Also, nir_deref_var is the top-level concept, and
nir_deref_array/nir_deref_record are child nodes.
This patch attempts to allocate nir_deref_vars out of their parent
instruction, and any sub-dereferences out of their parent deref.
It enforces these restrictions in the validator as well.
This means that freeing an instruction should free its associated
dereference chain as well. The memory sweeper pass can also happily
ignore them.
v2: Rename make_deref to evaluate_deref and make it take a nir_instr *
instead of void *. This involves adding &instr->instr everywhere.
(Requested by Jason Ekstrand.)
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
Almost all instructions we nir_ssa_def_init() for are nir_dests, and you
have to keep from forgetting to set is_ssa when you do. Just provide the
simpler helper, instead.
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
