Commit 08bfd710a2. (nir/dead_cf: Stop
relying on liveness analysis) introduced a new check that iterated
through a SSA def's uses, to see if it's used. But it only checked
normal uses, and not uses which are part of an 'if' condition. This
led to it thinking more nodes were dead than possible.
Fixes Piglit's variable-indexing/tcs-output-array-float-index-wr test
(and related tests) with the out-of-tree Iris driver.
Fixes: 08bfd710a2 nir/dead_cf: Stop relying on liveness analysis
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
The idea here is to reassociate a * (b * c) into (a * c) * b, when
b is a non-constant value, but a and c are constants, allowing them
to be combined.
But nothing was enforcing that 'b' must be non-constant, which meant
that running opt_algebraic in a loop would never terminate if the IR
contained non-folded constant expressions like 256 * 0.5 * 2. Normally,
we call constant folding in such a loop too, but IMO it's better for
nir_opt_algebraic to be robust and not rely on that.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109581
Fixes: 32e266a9a5 i965: Compile fp64 funcs only if we do not have 64-bit hardware support
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
This was probably useful when it was first written, however it
looks to be no longer necessary.
As far as I can tell these days dce is smart enough to remove useless
instructions from if branches. Once this is done
nir_opt_peephole_select() will end up removing the empty if.
Removing this support reduces the dolphin uber shader compilation
time spent in nir_opt_dead_cf() by a little over 7x.
No shader-db changes on i965 or radeonsi.
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
In opt_peel_initial_if optimization, when moving the continue list to
end of the continue block, before the jump, could happen that the
continue list itself also ends with a jump.
This would mean that we would have two jump instructions in a row: the
first one from the continue list and the second one from the contine
block.
As inserting an instruction after a jump is not allowed (and it does not
make sense, as it will not be executed), remove the jump from the
continue block and keep the one from continue list, as it will be
executed first.
CC: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
opt_split_alu_of_phi moves ALU instruction to the end of continue block.
But if the continue block ends with a jump instruction (an explicit
"continue" instruction) then the ALU must be inserted before the jump,
as it is illegal to add instructions after the jump.
CC: Ian Romanick <ian.d.romanick@intel.com>
Fixes: 0881e90c09 ("nir: Split ALU instructions in loops that read phis")
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
The liveness analysis pass is fairly expensive because it has to build
large bit-sets and run a fix-point algorithm on them. Instead of
requiring liveness for detecting if values escape a CF node, just take
advantage of the structured nature of NIR and use block indices instead.
This only requires the block index metadata which is the fastest we have
metadata to generate.
No shader-db changes on Kaby Lake
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
We want to handle live SSA values differently and it's going to involve
walking the instructions. We can make it a single instruction walk if
we combine it with cf_node_has_side_effects.
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
[28/716] Compiling C object 'src/compiler/nir/068b2c8@@nir@sta/nir_gather_xfb_info.c.o'.
../src/compiler/nir/nir_gather_xfb_info.c: In function ‘nir_gather_xfb_info’:
../src/compiler/nir/nir_gather_xfb_info.c:171:13: warning: variable ‘max_offset’ set but not used [-Wunused-but-set-variable]
unsigned max_offset[NIR_MAX_XFB_BUFFERS] = {0};
^~~~~~~~~~
[36/716] Compiling C object 'src/compiler/nir/068b2c8@@nir@sta/nir_instr_set.c.o'.
../src/compiler/nir/nir_instr_set.c:502:1: warning: ‘instr_each_src_and_dest_is_ssa’ defined but not used [-Wunused-function]
instr_each_src_and_dest_is_ssa(nir_instr *instr)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Everything should be in ssa form when we call this. This is a
hotpath so replace the check with an assert.
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Everthing should be in ssa form when this is called. Checking
for it here is expensive so turn this into an assert instead.
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
There is no need to hash the instruction twice, especially as we
end up adding it in the majority of cases.
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
if we have something like this:
loop {
...
if x {
break;
} else {
continue;
}
}
opt_if_loop_last_continue returns true marking progress allthough nothing
changes.
Fixes: 5921a19d4b "nir: add if opt opt_if_loop_last_continue()"
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Patch adds nir_lower_tex_options as parameter to sample_plane so that
we don't need to extend nir_tex_instr for this.
Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Eric and I would like a bitmask of which samplers are used, similar to
prog->SamplersUsed, but available in NIR. The linker uses SamplersUsed
for resource limit checking, but later optimizations may eliminate more
samplers. So instead of propagating it through, we gather a new one.
While there, we also gather the existing textures_used_by_txf bitmask.
Gathering these bitfields in nir_shader_gather_info is awkward at best.
The main reason is that it introduces an ordering dependency between the
two passes. If gathering runs before lower_samplers_as_deref, it can't
look at var->data.binding. If the driver doesn't use the full lowering
to texture_index/texture_array_size (like radeonsi), then the gathering
can't use those fields. Gathering might be run early /and/ late, first
to get varying info, and later to update it after variant lowering. At
this point, should gathering work on pre-lowered or post-lowered code?
Pre-lowered is also harder due to the presence of structure types.
Just doing the gathering when we do the lowering alleviates these
ordering problems. This fixes ordering issues in i965 and makes the
txf info gathering work for radeonsi (though they don't use it).
Reviewed-by: Eric Anholt <eric@anholt.net>
When nir_rematerialize_derefs_in_use_blocks_impl was first written, I
attempted to optimize things a bit by not bothering to re-materialize
the sources of deref instructions figuring that the final caller would
take care of that. However, in the case of more complex deref chains
where the first link or two lives in block A and then another link and
the load/store_deref intrinsic live in block B it doesn't work. The
code in rematerialize_deref_in_block looks at the tail of the chain,
sees that it's already in block B and skips it, not realizing that part
of the chain also lives in block A.
The easy solution here is to just rematerialize deref sources of deref
instructions as well. This may potentially lead to a few more deref
instructions being created by the conditions required for that to
actually happen are fairly unlikely and, thanks to the caching, it's all
linear time regardless.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109603
Fixes: 7d1d1208c2 "nir: Add a small pass to rematerialize derefs per-block"
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
v2: Remove the original ALU instruciton after all of its readers are
modified to read the new ALU instruction.
v3: Fix an issue where a bcsel that may not be executed on a loop
iteration due to a break statement is converted to a phi (and therefore
incorrectly "executed"). Noticed by Tim.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109216
Fixes: 8fb8ebfbb0 ("intel/compiler: More peephole select")
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
A single shader in Unigine Superposition is affected by this change.
A single iadd is moved to the end of a loop. This iadd is involved in
a complex set of logic to terminate the loop, and an extra mov
instruction is inserted. This shader really needs the optimization
suggested by bugzilla #94747, and I expect that to make this tiny
regression go away.
All Gen7+ platforms had similar results. (Skylake shown)
total instructions in shared programs: 15047543 -> 15047545 (<.01%)
instructions in affected programs: 565 -> 567 (0.35%)
helped: 0
HURT: 2
total cycles in shared programs: 369977253 -> 369978253 (<.01%)
cycles in affected programs: 127910 -> 128910 (0.78%)
helped: 0
HURT: 2
v2: Skip nir_op_vec{2,3,4} and nir_op_[fi]mov instructions to avoid
infinite optimization loops. Remove the original ALU instruciton after
all of its readers are modified to read the new ALU instruction.
v3: Extend to the more general case. The if the prev-block value from
the phi is not undef, this means the ALU instruction has to be
duplicated in both the prev-block and the continue-block.
Fixes: 8fb8ebfbb0 ("intel/compiler: More peephole select")
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
This will be used in a couple more places soon.
The function name is... horribly long. Neither Matt nor I could think
of any thing that was shorter and still more descriptive than
"is_phi_foo". I'm willing to entertain suggestions.
Fixes: 8fb8ebfbb0 ("intel/compiler: More peephole select")
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
There are a number of reasons for the rewrite.
1. Adding support for packing tess patch varyings in a sane way.
2. Making use of qsort allowing the code to be much easier to
follow.
3. Fixes a bug where different interp types caused component
packing to be skipped for all varyings in some scenarios.
4. Allows us to add a crude live range analysis for deciding
which components should be packed together. This support can
optionally be added in a future patch.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
This will be used in the following patches to determine if we
support packing the components of a varying.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
This adds support needed for marking the varyings as used but we
don't actually support packing patches in this patch.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Compact arrays are used for special variables like clip and cull
distances, or tessellation levels. Drivers using compact arrays
assume that these values will always be actual arrays. We don't
want to turn a float[1] gl_CullDistance into a single float; that
would confuse drivers.
Today, i965 uses compact arrays, and Gallium drivers use
nir_lower_io_arrays_to_elements, so we haven't had any overlap
that would demonstrate the issue. Iris will use both.
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
A couple places in st/nir assume that cull distances have been lowered
away, so it will need to call this lowering pass for drivers which opt
out of the GLSL IR lowering. The Intel backend also calls this pass,
for i965 and anv. We need to only do it once.
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
We have a GLSL IR pass to convert clip/cull distance float[] arrays
into vec4[2] arrays. In ff281e6204, we attempted to skip this pass
if the GLSL IR lowering had already run. But, that code was not quite
right, as we forgot to strip away the per-vertex IO array layer for
geometry and tessellation shader varyings.
If the GLSL IR pass has run, the variables will not be marked as
"compact". So we can simply check that and bail.
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
radeonsi uses a system value for gl_FragCoord rather than an input var.
These get translated into load_frag_coord NIR intrinsics, which lose the
pixel_center_integer and origin_upper_left decorations. To cope with
this, Tim added a shader_info field for pixel_center_integer, and made
glsl_to_nir set it accordingly.
prog_to_nir also needs to handle these fragcoord conventions. Instead
of duplicating the logic to set the info field, just move it to
nir_lower_system_values so it'll happen regardless of who makes the NIR.
(For what it's worth, we don't need an info flag for origin_upper_left,
because radeonsi lowers origin conventions in nir_lower_wpos_ytransform
before nir_lower_system_values destroys the variable and qualifiers.)
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
All things being equal is better to keep the original order. Since
the new block is empty, push the phis in order to tail.
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Daniel Schürmann <daniel.schuermann@campus.tu-berlin.de>
Use the trick of adding and then subtracting 2**52 (52 is the number of
explicit mantissa bits a double-precision floating-point value has) to
implement round-to-even.
Cuts the number of instructions on SKL of the piglit test
fs-roundEven-double.shader_test from 109 to 21.
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
These correspond roughly to reading/writing OpenCL global pointers. The
idea is that they just take a bare address and load/store from it. Of
course, exactly what this address means is driver-dependent.
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
In order to allow nir_gather_xfb_info to be used on OpenGL,
specifically ARB_gl_spirv.
So, from OpenGL 4.6 spec, section 11.1.2.1, "Output Variables":
"outputs specifying both an *XfbBuffer* and an *Offset* are
captured, while outputs not specifying both of these are not
captured. Values are captured each time the shader writes to such
a decorated object."
This implies that are captured if both are present, and not if one of
those are lacking. Technically, it doesn't explicitly point that
having just one or the other is a mistake. In some cases, glslang is
adding some extra XfbBuffer without XfbOffset around, and mentioning
that technically that is not a bug (see issue#1526)
And for the case of Vulkan, as the same glslang issue mentions, it is
not clear if that should be a mistake or not. But even if it is a
mistake, it is not really needed to be checked on the driver, and we
can let the validation layers to check that.
v2: simplify explicit_xfb_buffer and explicit_offset checks (Jason).
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Before, we were double-counting the component slots when we had a dvec3
or dvec4. Instead, just add them in once and manually offset the
recorded output offset.
Fixes: 19064b8c "nir: Add a pass for gathering transform feedback info"
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
If we have a transform feedback output like:
float[2] x2_out (VARYING_SLOT_VAR1.x, 0, 0)
which is lowered by nir_lower_io_arrays_to_elements to,
float x2_out (VARYING_SLOT_VAR1.x, 0, 0)
float x2_out@5 (VARYING_SLOT_VAR2.x, 0, 0)
We have to update the destination offset to avoid overwriting
the same value.
v2 (Jason Ekstrand):
- Compute the correct offsets for arrays of vectors and/or doubles
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
When a xfb buffer is explicitely declared on a varying
variable, we shouldn't remove it at link time.
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
