This change makes copy propagation pass faster. Complete link time
spent in test case attached to bug 94477 goes down to ~400 secs from
over 500 secs on my HSW machine. Does not fix the actual issue but
brings down the total. No regressions seen in CI.
v2: do not leak hash_table structure
Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Valgrind detected that variable ir_copy_propagation_visitor::killed_all
is uninitialized.
Signed-off-by: Jan Ziak (http://atom-symbol.net) <0xe2.0x9a.0x9b@gmail.com>
Signed-off-by: Rob Clark <robdclark@gmail.com>
We've had a FINISHME here since Eric originally wrote the code in 2010.
This patch implements his suggested approach, which makes us actually
able to copy propagate into the loops, at the unfortunate cost of making
this pass even more expensive.
The shader-db statistics are not terribly impressive:
total instructions in shared programs: 9008589 -> 9008613 (0.00%)
instructions in affected programs: 4293 -> 4317 (0.56%)
helped: 0
HURT: 10
total cycles in shared programs: 78550978 -> 78575760 (0.03%)
cycles in affected programs: 655426 -> 680208 (3.78%)
helped: 75
HURT: 88
GAINED: 2
Most of the "regressions" appear to be us successfully copy propagating
uniforms, which i965 is loading as pull constants instead of push, so we
occasionally have two pulls instead of one. That doesn't seem like this
pass's job - it's propagating correctly, and we should be smarter about
pull loads in the backend.
This patch is also useful for a couple of reasons:
1. It can clean up copies created by varying packing (previously, we
couldn't if the uses were inside a loop).
This fixes a bug when interpolateAt*() is used on a packed varying
inside a loop: glsl_to_nir struggles to see through the extra copy
and mistakenly believed the variable was not an input.
2. It will help propagate uniform array access created by
lower_const_array_to_uniforms().
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.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>
