Set of opcodes doesn't have enough flexibility in certain cases. E.g.
Utgard PP has vector conditional select operation, but condition is always
scalar. Lowering all the vector selects to scalar increases instruction
number, so we need a way to filter only those ops that can't be handled
in hardware.
Reviewed-by: Qiang Yu <yuq825@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
These helpers are unused, as flagged by cppcheck.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
In practice, the new post-schedule print is just as useful.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
It has not been used in a long time; I forgot this file even existed.
Flagged by cppcheck.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
We already had a perfectly cromulent pass for this, but one landed in
common NIR code so let's switch and lighten our tree.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
This optimization depended on RA running before scheduling. It therefore
no longer applies and is now unused.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
This is a tradeoff.
Scheduling before RA means we don't do RA on what-will-become pipeline
registers. Importantly, it means the scheduler is able to reorder
instructions, as registers have not been decided yet.
Unfortunately, it also complicates register spilling, since the spills
themselves won't get bundled optimally and we can only spill twice per
ALU bundle (only one spill per bundle allowed here). It also prevents us
from eliminating dead moves introduced by register allocation, as they
are not dead before RA. The shader-db regressions are from poor spilling
choices introduced by the new bundling requirements. These could be
solved by the combination of a post-scheduler (to combine adjacent
spills into bundles) with a VLIW-aware spill cost calculation.
Nevertheless, the change is small enough that I feel it's worth it to
eat a tiny shader-db regression for the sake of flexibility.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Rather than using a pile of hacks and awkward constructs in MIR to
ensure the writeout parameter gets written into r0, let's add a
dedicated shadow register class for writeout (interfering with work
register r0) so we can express the writeout condition succintly and
directly.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
There's no slot for it; you'll end up writing into the void and
clobbering stuff. Don't. do it.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
When running the register allocator after scheduling, the MIR looks a
little different, so we need to extend the RA to handle a few of these
extra cases correctly.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
After scheduling, we still have valid MIR, but we have additional
bundling annotations which we would like to keep debug, so print these.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Rather than a vague "br.??" line, annotate the branch with its target
type (useful for disambiguating discards) and whether it was inverted.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
I'm not sure if this is strictly necessary but it makes debugging easier
and minimizes the diff with the experimental scheduler.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Scheduling occurs on a per-block basis, strongly assuming that a given
block contains at most a single branch. This does not always map to the
source NIR control flow, particularly when discard intrinsics are
involved. The solution is to allow scheduling barriers, which will
terminate a block early in code generation and open a new block.
To facilitate this, we need to move some post-block processing to a new
pass, rather than relying hackily on the current_block pointer.
This allows us to cleanup some logic analyzing branches in other parts
of the driver us well, now that the MIR is much more well-formed.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
It's sometimes convenient to call this with no instruction specified. By
definition, a missing instruction cannot reference any argument, so
let's check for NULL and shortciruit to false.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
The branch has the writeout specified in its source list, making this
special even if it's not explicitly part of r0.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
In order to run register allocation after scheduling, it is sometimes
necessary to be able to insert instructions into an already-scheduled
program. This is suboptimal, since it forces us to do a worst-case
scheduling, but it is nevertheless required for correct handling of
spills/fills. Let's add helpers to insert instructions as standalone
bundles for use in spilling code.
These helpers are minimal -- they *only* work on load/store ops or
moves. They should not be used for anything but register spilling; any
other instructions should be added prior to the schedule.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
While it doesn't matter with an unconditional move to the conditional
register (r31), when we try to elide that move we'll need to track the
swizzle explicitly, and there is no slot for that yet since ALU ops are
normally binary.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Oh boy. Midgard scheduling is crazy... These are all just the
requirements, not even the algorithm yet.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
This does not affect shaders in any way. Rather, it makes the shader-db
instruction count recorded in the compiler accurate with the in-order
scheduler, matching up with what we calculate from pandecode.
Though shaders are the same, instruction counts cannot be compared
across this commit for this reason.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Instructions attached to blocks are never explicitly freed. Let's
use ralloc() to attach those objects to the compiler context so that
they are automatically freed when the ctx object is freed.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Add an assert() in schedule_bundle() to make sure all instruction
pointers in bundle.instructions[] are valid.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Right now we're leaking all block and instruction objects allocated by
the compiler. Let's clean things up before leaving
midgard_compile_shader_nir().
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
When moving constants, if switching to a floating-point representation
doesn't break anything, we'd rather have an fmov than an imov,
permitting inlining the constant in many circumstances.
total quadwords in shared programs: 3408 -> 3366 (-1.23%)
quadwords in affected programs: 1188 -> 1146 (-3.54%)
helped: 41
HURT: 0
helped stats (abs) min: 1 max: 2 x̄: 1.02 x̃: 1
helped stats (rel) min: 0.19% max: 25.00% x̄: 9.65% x̃: 11.11%
95% mean confidence interval for quadwords value: -1.07 -0.98
95% mean confidence interval for quadwords %-change: -11.38% -7.93%
Quadwords are helped.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Storing constants as float doesn't make sense when we have integer
instructions; better to switch to be integer natively and coerce to/from
float rather than the opposite.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
We can statically determine from the disassembly if helper invocations
will be needed, so we can validate the corresponding bit in the
cmdstream and thus avoid printing the bit itself in the decode.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
We check for texture ops which calculate derivatives (either explicitly
via dFd* or implicitly) and mark the shader as requiring helper
invocations.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
