Originally you had to have one or the other. But actually I don't want
either. (Or rather I want whatever is the minimum # of instructions.)
TODO: not sure where the best place to insert a check that driver hasn't
set *both* lower_negate and lower_sub?
Signed-off-by: Rob Clark <robclark@freedesktop.org>
In freedreno these get implemented as the matching f* instruction plus a
u2f to convert the result to float 1.0/0.0. But less lines of code to
just let nir_opt_algebraic handle this for us, plus opens up some small
window for other opt passes to improve (ie. if some shader ended up with
both a flt and slt with same src args, for example).
v2: use b2f rather than u2f
Signed-off-by: Rob Clark <robclark@freedesktop.org>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
No shader-db changes, probably because they're all removed by the GLSL
compiler optimization added in commit 69ad5fd4.
Reviewed-by: Eric Anholt <eric@anholt.net>
Doesn't work for analogous && cases, because of NaNs.
total instructions in shared programs: 6195712 -> 6194829 (-0.01%)
instructions in affected programs: 42000 -> 41117 (-2.10%)
helped: 403
Reviewed-by: Eric Anholt <eric@anholt.net>
total instructions in shared programs: 4422307 -> 4422363 (0.00%)
instructions in affected programs: 4230 -> 4286 (1.32%)
helped: 0
HURT: 12
While this does hurt some things, the losses are minor and it prevents the
compare-with-zero optimization from fighting with ffma which is much more
important.
Reviewed-by: Matt Turner <mattst88@gmail.com>
TGSI's conditional discards take float arg and negate it, so GLSL to TGSI
generates a b2f and negates that value. Only, in NIR we want a proper
bool once again, so we compare with 0. This is a lot of pointless extra
instructions.
total instructions in shared programs: 39735 -> 39702 (-0.08%)
instructions in affected programs: 1342 -> 1309 (-2.46%)
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Since we have patterns based on b2f, generate them if we see the b2f
equivalent using an iand. This is common when generating NIR from TGSI.
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
prog->nir will generate fsub opcodes, but i965 doesn't implement them.
We may as well lower them at the NIR level, since it's trivial to do.
Suggested by Connor Abbott.
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
I initially wrote this based on the "(('fneg', ('fneg', a)), a)" above,
but we can generalize it and make it more potentially useful. In the
specific original case of a 0 for our new 'a' argument, it'll get further
algebraic optimization once the 0 is an argument to the new add.
No shader-db effects.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
vc4 was already cleaning these up, but it does shave 4 NIR instructions in
shader-db.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
This could be done in a separate pass like we do in GLSL IR, but it seems
to me like having the definitions of the transformations in the two
directions next to each other makes a lot of sense.
v2: Reorder the comment about the transformation.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Mesa has a shader compiler struct flagging whether GLSL IR's opt_algebraic
and other passes should try and generate certain types of opcodes or
patterns. Extend that to NIR by defining our own struct, which is
automatically generated from the Mesa struct in glsl_to_nir and provided
directly by the driver in TGSI-to-NIR.
v2: Split out the previous two prep patches.
v3: Rebase to master (no TGSI->NIR present)
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org> (v2)
And unfortunately other shaders do the same thing but with >=/<= which
we can't apply this optimization to because of NaNs.
instructions in affected programs: 23309 -> 22938 (-1.59%)
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
No change on shader-db on i965.
v2: Reword the comment due to feedback from Erik Faye-Lund
Reviewed-by: Connor Abbott <cwabbott0@gmail.com> (v1)
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com> (v1)
We've probably never seen this ridiculous pattern in the wild, so it
didn't matter.
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
We end up with these from TGSI-to-NIR because the pass generating the
comparisons doesn't know if the arg is actually a bool input or not. vc4
results:
total instructions in shared programs: 41801 -> 41508 (-0.70%)
instructions in affected programs: 4253 -> 3960 (-6.89%)
Reviewed-by: Matt Turner <mattst88@gmail.com>
Most of these exist in the GLSL IR algebraic pass already. However,
SSA allows us to find more instances of the patterns.
total NIR instructions in shared programs: 2015593 -> 2011430 (-0.21%)
NIR instructions in affected programs: 124189 -> 120026 (-3.35%)
helped: 604
total i965 instructions in shared programs: 6025505 -> 6018717 (-0.11%)
i965 instructions in affected programs: 261295 -> 254507 (-2.60%)
helped: 1295
HURT: 3
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
The first batch removes bonus fnot/inot operations, possibly allowing
other optimizations to better recognize patterns.
The next batch replaces a fadd and constant 0.0 with an fneg - negation
is usually free on GPUs, while addition is not.
total NIR instructions in shared programs: 2020814 -> 2015593 (-0.26%)
NIR instructions in affected programs: 411143 -> 405922 (-1.27%)
helped: 2233
HURT: 214
A few shaders are hurt by a few instructions due to moving neg such
that it has a constant operand, which is then folded, resulting in two
distinct load_consts for x and -x. We can always clean that up later.
total i965 instructions in shared programs: 6035392 -> 6025505 (-0.16%)
i965 instructions in affected programs: 784980 -> 775093 (-1.26%)
helped: 4508
HURT: 2
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
The GLSL IR optimization pass contained these; we may as well include
them too.
v2: Fix a >> 0 and a << 0 optimizations (caught by Matt).
No change in the number of NIR instructions on a shader-db run.
total i965 instructions in shared programs: 6035397 -> 6035392 (-0.00%)
i965 instructions in affected programs: 542 -> 537 (-0.92%)
helped: 2 (in glamor)
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Matt and I noticed a bunch of "val <- ior a a" operations in a shader,
so we decided to add an algebraic optimization for that. While there,
I decided to add a bunch more of them.
v2: Delete bogus fand/for optimizations (caught by Jason).
total NIR instructions in shared programs: 2023511 -> 2020814 (-0.13%)
NIR instructions in affected programs: 149634 -> 146937 (-1.80%)
helped: 1032
total i965 instructions in shared programs: 6035392 -> 6035397 (0.00%)
i965 instructions in affected programs: 537 -> 542 (0.93%)
HURT: 2
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
This pass uses the previously built algebraic transformations framework and
should act as an example for anyone else wanting to make an algebraic
transformation pass for NIR.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
