Currently only one ir assignment is removed for each var in a single
dead code optimisation pass. This means if a var has more than one
assignment, then it requires all the glsl optimisations to be run again
for each additional assignment to be removed.
Another pass is also required to remove the variable itself.
With this change all assignments and the variable are removed in a single
pass.
Some of the arrays of arrays conformance tests that were looping
through 8 dimensions ended up with a var with hundreds of assignments.
This change helps ES31-CTS.arrays_of_arrays.InteractionFunctionCalls1
go from around 3 min 20 sec -> 2 min
ES31-CTS.arrays_of_arrays.InteractionFunctionCalls2 went from
around 9 min 20 sec to 7 min 30 sec
I had difficulty getting the public shader-db to give a consistent result
with or without this change but the results seemed unchanged at between
15-20 seconds.
Thomas Helland measured change with shader-db on his machine from
approx 117 secs to 112 secs.
V3: Simplify freeing of list as suggested by Ian, and spelling fixes.
V2: Add assert to be sure references are counted before assignments.
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Tested-By: Thomas Helland <thomashelland90@gmail.com>
Tested-by: Ian Romanick <ian.d.romanick@intel.com>
This patch replaces the ir_loop fields "from", "to", "increment",
"counter", and "cmp" with a single integer ("normative_bound") that
serves the same purpose.
I've used the name "normative_bound" to emphasize the fact that the
back-end is required to emit code to prevent the loop from running
more than normative_bound times. (By contrast, an "informative" bound
would be a bound that is informational only).
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
If an ir_loop has a non-null "counter" field, the variable referred to
by this field is implicitly read and written by the loop. We need to
account for this in ir_variable_refcount, otherwise there is a danger
we will try to dead-code-eliminate the loop counter variable.
Note: at the moment the dead code elimination bug doesn't occur due to
a bug in ir_hierarchical_visitor: it doesn't visit the "counter"
field, so dead code elimination doesn't treat it as a candidate for
elimination. But the patch to follow will fix that bug, so we need to
fix ir_variable_refcount first in order to avoid breaking dead code
elimination.
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Exporting a publicly visible class with a generic name like
"variable_entry" via ir_variable_refcount.h is kind of mean.
Many IR transformers would like to define their own "variable_entry"
class. If they accidentally include this header, the compiler/linker
may get confused and try to instantiate the wrong variable_entry class,
leading to bizarre runtime crashes.
The hope is that renaming this one will allow .cpp files to safely
declare and use their own file-scope "variable_entry" classes.
This avoids crashes caused by converting src/glsl to automake.
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-and-tested-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
