As per this optimisations description:
"Takes assignments to variables that are dereferenced only
once and pastes the RHS expression into where the variables
dereferenced."
However the optimisation is run at compile time before multiple
shaders from the same stage could have been pasted together.
So this optimisation can incorrectly assume a global is only
referenced once since it cannot see the other pieces of the
shader stage until link time.
Here we skip the optimisation if the variable is a global. We
could change it to only run at link time however this
optimisation is only run at link time if we are being forced
to use GLSL IR to inline a function that glsl to nir cannot
handle and this will also be removed in a future patchset.
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/10482
Fixes: d75a36a9ee ("glsl: remove do_copy_propagation_elements() optimisation pass")
Acked-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27351>
Extra validation is added to ir_validate to make sure this is
always updated to the correct numer of operands, as passes like
lower_instructions modify the instructions directly rather then
generating a new one.
The reduction in time is so small that it is not really
measurable. However callgrind was reporting this function as
being called just under 34 million times while compiling the
Deus Ex shaders (just pre-linking was profiled) with 0.20%
spent in this function.
v2:
- make num_operands a unit8_t
- fix unsigned/signed mismatches
Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
git grep -l comparitor | xargs sed -i 's/comparitor/comparator/g'
Just happened to notice this in a patch that was sent and included one
of the tokens in question.
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Acked-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
This is kind of a hack. We currently track precise requirements
by decorating ir_variables. Propagating or grafting the RHS of an
assignment to a precise value into some other expression tree can
lose those decorations.
In the long run, it might be better to replace these ir_variable
decorations with an "exact" decoration on ir_expression nodes,
similar to what NIR does.
In the short run, this is probably good enough. It preserves
enough information for glsl_to_nir to generate "exact" decorations,
and NIR will then handle optimizing these expressions reasonably.
Fixes ES31-CTS.gpu_shader5.precise_qualifier.
v2: Drop invariant handling, as it shouldn't be necessary (caught
by Jason Ekstrand).
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
