Commit graph

2290 commits

Author SHA1 Message Date
Jason Ekstrand
5bfce5fcc2 nir/system_values: Use the bit size from the load_deref
This isn't a great solution for bit-sizes but we don't have a
particularly convenient way to get a bit size from the system value enum
and this keeps the lowering pass from changing it.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
2018-10-26 11:45:29 -05:00
Jason Ekstrand
a3b4cb3458 nir/opt_if: Rework condition propagation
Instead of doing our own constant folding, we just emit instructions and
let constant folding happen.  This is substantially simpler and lets us
use the nir_imm_bool helper instead of dealing with the const_value's
ourselves.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2018-10-26 11:45:29 -05:00
Jason Ekstrand
4cd8a58595 nir/search: Use the nir_imm_* helpers from nir_builder
This requires that we rework the interface a bit to use nir_builder but
that's a nice little modernization anyway.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
2018-10-26 11:45:29 -05:00
Jason Ekstrand
6e32115bd6 nir/builder: Handle 16-bit floats in nir_imm_floatN_t
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
2018-10-26 11:45:29 -05:00
Jason Ekstrand
ff45649bc2 nir/builder: Add a nir_imm_true/false helpers
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
2018-10-26 11:45:29 -05:00
Jason Ekstrand
249e32ab17 nir/constant_folding: Use nir_src_as_bool for discard_if
Missed one while converting to the nir_src_as_* helpers.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
2018-10-26 11:45:29 -05:00
Jason Ekstrand
6de1869e86 nir/constant_folding: Add an unreachable to a switch
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
2018-10-26 11:45:29 -05:00
Jason Ekstrand
28bb6abd1d nir/validate: Print when the validation failed
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
2018-10-26 11:45:29 -05:00
Eric Engestrom
e27902a261 util: use C99 declaration in the for-loop set_foreach() macro
Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2018-10-25 12:43:18 +01:00
Eric Engestrom
bb84fa146f util: use C99 declaration in the for-loop hash_table_foreach() macro
Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2018-10-25 12:43:18 +01:00
Jose Fonseca
d9a04196d9 nir: Fix array initializer.
Empty initializer is not standard C.  This fixes MSVC build.

Trivial.
2018-10-24 11:37:09 +01:00
Juan A. Suarez Romero
3112da346b nir: fix nir_copy_propagation test
Use nir_src_comp_as_uint() to read the proper second component, as
nir_src_as_uint() returns the first one.

v2: Use nir_src_comp_as_uint() [Jason]

Fixes: 16870de8a0 ("nir: Use nir_src_is_const and nir_src_as_* in core
                     code")
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108532
Tested-by: Michel Dänzer <michel.daenzer@amd.com>
Tested-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-10-24 09:13:24 +02:00
Samuel Pitoiset
7c694cbfa4 nir: add linking helper nir_link_xfb_varyings()
The linking opts shouldn't try removing or compacting XFB varyings
in the consumer. To avoid this we copy the always_active_io flag
from the producer.

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2018-10-24 08:21:29 +11:00
Jason Ekstrand
ecb7775e1c nir/algebraic: Fix a typo in the bit size validation code
The conon_bit_class and canon_var_class variables got switched.

Fixes: 932c650e0b "nir/algebraic: Loosen a restriction on variables"
Reported-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2018-10-23 12:22:29 -05:00
Jason Ekstrand
bf441d22a7 nir/algebraic: Provide descriptive asserts for bit size checks
This will hopefully make debugging opt_algebraic bit-size compile
failures easier.

Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
2018-10-22 16:00:18 -05:00
Jason Ekstrand
932c650e0b nir/algebraic: Loosen a restriction on variables
Previously, we would fail if a variable had an assigned but unknown bit
size X and we tried to assign it an actual bit size.  However, this is
ok because, at the time we do the search, the variable does have an
actual bit size and it will match X because of the NIR rules.

Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
2018-10-22 16:00:18 -05:00
Jason Ekstrand
ea9e651423 nir/algebraic: A bit of validation refactoring'
We rename some local variables in validate() to be more readable and
plumb the var through to get/set_var_bit_class instead of the var index.

Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
2018-10-22 16:00:18 -05:00
Jason Ekstrand
641f4be8e8 nir/algebraic: Make internal classes str-able
Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
2018-10-22 16:00:18 -05:00
Jason Ekstrand
6068be543b nir/algebraic: Generalize an optimization
There's nothing boolean about (a | ~a) ~> -1

Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
2018-10-22 16:00:18 -05:00
Jason Ekstrand
69618a8678 nir/algebraic: Use bool internally instead of bool32
Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
2018-10-22 16:00:18 -05:00
Jason Ekstrand
16870de8a0 nir: Use nir_src_is_const and nir_src_as_* in core code
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
2018-10-22 14:24:15 -05:00
Jason Ekstrand
ce36f412c9 nir/search_helpers: Use nir_src_is_const and friends
This not only makes them safe for more bit sizes but it also fixes a bug
in is_zero_to_one where it would return true for constant NaN.

Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
2018-10-22 14:24:15 -05:00
Jason Ekstrand
7bae7828aa nir/search: Use nir_src_is_const and friends
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
2018-10-22 14:24:15 -05:00
Jason Ekstrand
bca5c2c688 nir: Add some new helpers for working with const sources
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
2018-10-22 14:24:15 -05:00
Dave Airlie
ff281e6204 nir: fix clip cull lowering to not assert if GLSL already lowered.
If GLSL has already done the lowering, we'd rather not crash in this pass.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2018-10-15 18:53:48 -07:00
Caio Marcelo de Oliveira Filho
b3c6146925 nir: Copy propagation between blocks
Extend the pass to propagate the copies information along the control
flow graph.  It performs two walks, first it collects the vars
that were written inside each node. Then it walks applying the copy
propagation using a list of copies previously available.  At each node
the list is invalidated according to results from the first walk.

This approach is simpler than a full data-flow analysis, but covers
various cases.  If derefs are used for operating on more memory
resources (e.g. SSBOs), the difference from a regular pass is expected
to be more visible -- as the SSA copy propagation pass won't apply to
those.

A full data-flow analysis would handle more scenarios: conditional
breaks in the control flow and merge equivalent effects from multiple
branches (e.g. using a phi node to merge the source for writes to the
same deref).  However, as previous commentary in the code stated, its
complexity 'rapidly get out of hand'.  The current patch is a good
intermediate step towards more complex analysis.

The 'copies' linked list was modified to use util_dynarray to make it
more convenient to clone it (to handle ifs/loops).

Annotated shader-db results for Skylake:

    total instructions in shared programs: 15105796 -> 15105451 (<.01%)
    instructions in affected programs: 152293 -> 151948 (-0.23%)
    helped: 96
    HURT: 17

        All the HURTs and many HELPs are one instruction.  Looking
        at pass by pass outputs, the copy prop kicks in removing a
        bunch of loads correctly, which ends up altering what other
        other optimizations kick.  In those cases the copies would be
        propagated after lowering to SSA.

        In few HELPs we are actually helping doing more than was
        possible previously, e.g. consolidating load_uniforms from
        different blocks.  Most of those are from
        shaders/dolphin/ubershaders/.

    total cycles in shared programs: 566048861 -> 565954876 (-0.02%)
    cycles in affected programs: 151461830 -> 151367845 (-0.06%)
    helped: 2933
    HURT: 2950

        A lot of noise on both sides.

    total loops in shared programs: 4603 -> 4603 (0.00%)
    loops in affected programs: 0 -> 0
    helped: 0
    HURT: 0

    total spills in shared programs: 11085 -> 11073 (-0.11%)
    spills in affected programs: 23 -> 11 (-52.17%)
    helped: 1
    HURT: 0

        The shaders/dolphin/ubershaders/12.shader_test was able to
        pull a couple of loads from inside if statements and reuse
        them.

    total fills in shared programs: 23143 -> 23089 (-0.23%)
    fills in affected programs: 2718 -> 2664 (-1.99%)
    helped: 27
    HURT: 0

        All from shaders/dolphin/ubershaders/.

    LOST:   0
    GAINED: 0

The other generations follow the same overall shape.  The spills and
fills HURTs are all from the same game.

shader-db results for Broadwell.

    total instructions in shared programs: 15402037 -> 15401841 (<.01%)
    instructions in affected programs: 144386 -> 144190 (-0.14%)
    helped: 86
    HURT: 9

    total cycles in shared programs: 600912755 -> 600902486 (<.01%)
    cycles in affected programs: 185662820 -> 185652551 (<.01%)
    helped: 2598
    HURT: 3053

    total loops in shared programs: 4579 -> 4579 (0.00%)
    loops in affected programs: 0 -> 0
    helped: 0
    HURT: 0

    total spills in shared programs: 80929 -> 80924 (<.01%)
    spills in affected programs: 720 -> 715 (-0.69%)
    helped: 1
    HURT: 5

    total fills in shared programs: 93057 -> 93013 (-0.05%)
    fills in affected programs: 3398 -> 3354 (-1.29%)
    helped: 27
    HURT: 5

    LOST:   0
    GAINED: 2

shader-db results for Haswell:

    total instructions in shared programs: 9231975 -> 9230357 (-0.02%)
    instructions in affected programs: 44992 -> 43374 (-3.60%)
    helped: 27
    HURT: 69

    total cycles in shared programs: 87760587 -> 87727502 (-0.04%)
    cycles in affected programs: 7720673 -> 7687588 (-0.43%)
    helped: 1609
    HURT: 1416

    total loops in shared programs: 1830 -> 1830 (0.00%)
    loops in affected programs: 0 -> 0
    helped: 0
    HURT: 0

    total spills in shared programs: 1988 -> 1692 (-14.89%)
    spills in affected programs: 296 -> 0
    helped: 1
    HURT: 0

    total fills in shared programs: 2103 -> 1668 (-20.68%)
    fills in affected programs: 438 -> 3 (-99.32%)
    helped: 4
    HURT: 0

    LOST:   0
    GAINED: 1

v2: Remove the DISABLE prefix from tests we now pass.

v3: Add comments about missing write_mask handling. (Caio)
    Add unreachable when switching on cf_node type. (Jason)
    Properly merge the component information in written map
    instead of replacing. (Jason)
    Explain how removal from written arrays works. (Jason)
    Use mode directly from deref instead of getting the var. (Jason)

v4: Register the local written mode for calls. (Jason)
    Prefer cf_node instead of node. (Jason)
    Clarify that remove inside iteration only works in backward
    iterations. (Jason)

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-10-15 17:29:46 -07:00
Caio Marcelo de Oliveira Filho
dc349f07b5 nir: Take call instruction into account in copy_prop_vars
Calls are not used yet (functions are inlined), but since new code is
already taking them into account, do it here too.  The convention here
and in other places is that no writable memory is assumed to remain
unchanged, as well as global variables.

Also, explicitly state the modes affected (instead of using the
reverse logic) in one of the apply_for_barrier_modes calls.

Suggested by Jason.

v2: Consider local vars used by a call to be conservative, SPIR-V has
    such cases. (Jason)

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-10-15 17:29:46 -07:00
Caio Marcelo de Oliveira Filho
797f01c220 nir: Add tests for copy propagation of derefs
Also tests for removal of redundant loads, that we currently handle as
part of the copy propagation.

Note some tests involve multiple blocks and are currently DISABLED
because they (expectedly) fail.

v2: Add missing DISABLED prefix to "multi block" tests. (Jason)

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-10-15 17:29:46 -07:00
Caio Marcelo de Oliveira Filho
4dfa7adc10 nir: Remove handling of dead writes from copy_prop_vars
These are covered by another pass now.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-10-15 17:29:46 -07:00
Caio Marcelo de Oliveira Filho
cb126cf67a nir: Separate dead write removal into its own pass
Instead of doing this as part of the existing copy_prop_vars pass.

Separation makes easier to expand the scope of both passes to be more
than per-block.  For copy propagation, the information about valid
copies comes from previous instructions; while the dead write removal
depends on information from later instructions ("have any instruction
used this deref before overwrite it?").

Also change the tests to use this pass (instead of copy prop vars).
Note that the disabled tests continue to fail, since the standalone
pass is still per-block.

v2: Remove entries from dynarray instead of marking items as
    deleted.  Use foreach_reverse. (Caio)

    (all from Jason)
    Do not cache nir_deref_path.  Not worthy for this patch.
    Clear unused writes when hitting a call instruction.
    Clean up enumeration of modes for barriers.
    Move metadata calls to the inner function.

v3: For copies, use the vector length to calculate the mask.

    (all from Jason)
    Use nir_component_mask_t when applicable.
    Rename functions for clarity.
    Consider local vars used by a call to be conservative (SPIR-V has
    such cases).
    Comment and assert the assumption that stores and copies are
    always to a deref that ends with a vector or scalar.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-10-15 17:29:46 -07:00
Caio Marcelo de Oliveira Filho
a02fd7000d nir: Add tests for dead write elimination
Note at the moment the pass called is nir_opt_copy_prop_vars, because
dead write elimination is implemented there.

Also added tests that involve identifying dead writes in multiple
blocks (e.g. the overwrite happens in another block).  Those currently
fail as expected, so are marked to be skipped.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-10-15 17:29:46 -07:00
Caio Marcelo de Oliveira Filho
bbda2a17f7 nir: Add test file for vars related passes
Add basic helpers for doing tests on the vars related optimization
passes.  The main goal is to lower the barrier to create tests during
development and debugging of the passes.  Full coverage is not a
requirement.

v2: Make find_next_intrinsic() skip blocks before 'after'. (Jason)
    Move nir_imm_ivec2() to nir_builder.h. (Jason)

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-10-15 17:29:46 -07:00
Caio Marcelo de Oliveira Filho
c869646b7d nir: Add nir_imm_ivec2 helper
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-10-15 17:29:46 -07:00
Eric Anholt
7d77fe1bcc nir: Expose nir_remove_unused_io_vars().
For gallium drivers where you want to do some linking at variant compile
time, you don't have the other producer/consumer shader on hand to modify.
By exposing the inner function, the driver can have the used varyings in
the compiled shader cache key and still do linking.

This is also useful for V3D, where the binning shader wants to only output
position and TF varyings.  We've been removing those after nir_lower_io,
but this will be less driver-specific code and let more of the shader get
DCEed early in NIR.

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2018-10-15 17:16:44 -07:00
Eric Anholt
b788ab6d5c nir: Be sure to fix deref modes after demoting shader i/o vars to global.
Fixes assertion failures when calling nir_remove_unused_varyings() or
nir_remove_unused_io_vars().

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2018-10-15 17:16:44 -07:00
Kenneth Graunke
ed169c9ad2 nir: Create sampler2D variables in nir_lower_{bitmap,drawpixels}.
This is needed for nir_gather_info to actually count the new textures,
since it operates solely on variables.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Dave Airlie <airlied@redhat.com>
2018-10-14 23:35:35 -07:00
Samuel Pitoiset
4b74f05f6b spirv/nir: handle memory access qualifiers for SSBO loads/stores
v2: - change how the access qualifiers are accumulated
v3: - duplicate members in struct_member_decoration_cb()
    - handle access qualifiers on variables
    - remove access qualifiers handling in _vtn_variable_load_store()
    - fix setting access qualifiers on type->array_element

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net
2018-10-12 08:42:08 +02:00
Jason Ekstrand
d7e0d47b9d nir: Add a bunch of b2[if] optimizations
The b2f and b2i conversions always produce zero or one which are both
representable in every type and size.  Since b2i and b2f support all bit
sizes, we can just get rid of the conversion opcode.

total instructions in shared programs: 15089335 -> 15084368 (-0.03%)
instructions in affected programs: 212564 -> 207597 (-2.34%)
helped: 896
HURT: 0

total cycles in shared programs: 369831123 -> 369826267 (<.01%)
cycles in affected programs: 2008647 -> 2003791 (-0.24%)
helped: 693
HURT: 216

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2018-10-11 15:21:19 -05:00
Ian Romanick
a68dd47b91 nir/algebraic: Simplify fsat of fsign
These allows us to not support fsign.sat in the Intel compiler backend,
and that will simplify some later changes.

No shader-db changes on any Intel platform.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
2018-10-09 13:56:42 -07:00
Ian Romanick
1546204cdd nir/algebraic: sign(x)*x*x is abs(x)*x
shader-db results:

All Gen7+ platforms had similar results. (Skylake shown)
total instructions in shared programs: 15106023 -> 15105981 (<.01%)
instructions in affected programs: 300 -> 258 (-14.00%)
helped: 6
HURT: 0
helped stats (abs) min: 7 max: 7 x̄: 7.00 x̃: 7
helped stats (rel) min: 14.00% max: 14.00% x̄: 14.00% x̃: 14.00%
95% mean confidence interval for instructions value: -7.00 -7.00
95% mean confidence interval for instructions %-change: -14.00% -14.00%
Instructions are helped.

total cycles in shared programs: 566050327 -> 566050075 (<.01%)
cycles in affected programs: 2826 -> 2574 (-8.92%)
helped: 6
HURT: 0
helped stats (abs) min: 40 max: 44 x̄: 42.00 x̃: 42
helped stats (rel) min: 8.89% max: 8.94% x̄: 8.92% x̃: 8.92%
95% mean confidence interval for cycles value: -44.30 -39.70
95% mean confidence interval for cycles %-change: -8.95% -8.88%
Cycles are helped.

No changes on Gen6 or earlier.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
2018-10-09 13:56:42 -07:00
Ian Romanick
10f4a8871e nir: Add helper functions to get the instruction that generated a nir_src
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
2018-10-09 13:56:42 -07:00
Jason Ekstrand
dd553bc67f nir/alu_to_scalar: Use ssa_for_alu_src in hand-rolled expansions
The ssa_for_alu_src helper will correctly handle swizzles and other
source modifiers for you.  The expansions for unpack_half_2x16,
pack_uvec2_to_uint, and pack_uvec4_to_uint were all broken with regards
to swizzles.  The brokenness of unpack_half_2x16 was causing rendering
errors in Rise of the Tomb Raider on Intel ever since c11833ab24
which added an extra copy propagation to the optimization pipeline and
caused us to start seeing swizzles where we hadn't seen any before.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107926
Fixes: 9ce901058f "nir: Add lowering of nir_op_unpack_half_2x16."
Fixes: 9b8786eba9 "nir: Add lowering support for packing opcodes."
Tested-by: Alex Smith <asmith@feralinteractive.com>
Tested-by: Józef Kucia <joseph.kucia@gmail.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
2018-10-04 12:43:59 -05:00
Jason Ekstrand
00f385e6d4 nir/from_ssa: Don't rewrite derefs destinations to registers
We already call nir_rematerialize_derefs_in_use_blocks_impl prior to
calling nir_lower_ssa_defs_to_regs_block so the assertion that all deref
uses in the block should hold.  This fixes the following CTS test when
SPIR-V optimization recipe 1:

dEQP-VK.glsl.struct.local.loop_nested_struct_array_vertex

Fixes: 606eb56ab9 "intel/nir: Only lower load/store derefs"
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2018-10-02 10:24:56 -05:00
Jason Ekstrand
bfc89c668e nir/cf: Remove phi sources if needed in nir_handle_add_jump
If the block in which the jump is inserted is the predecessor of a phi
then we need to remove phi sources otherwise the phi may end up with
things improperly connected.  This fixes the following CTS test when
dEQP is run with SPIR-V optimization recipe 1:

dEQP-VK.glsl.functions.control_flow.return_in_nested_loop_vertex

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2018-10-02 10:24:56 -05:00
Juan A. Suarez Romero
0c82e3603e nir: add initializer data to fix MSVC compile error
CC: Jason Ekstrand <jason@jlekstrand.net>
Fixes: 82799a5d1b8 ("nir: Add a small pass to rematerialize derefs
per-block")
Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
2018-09-19 11:46:44 +02:00
Jason Ekstrand
976046a8d8 nir: Add some asserts that we don't put derefs in phis
The lcssa and phis_to_regs passes are used by various NIR optimizations
that modify the CFG.  Putting a couple of asserts will help ensure that
we don't accidentally put derefs in phis as part of an optimization
pass.

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2018-09-19 02:00:49 -05:00
Jason Ekstrand
864c780566 nir/opt_if: Re-materialize derefs in use blocks before peeling loops
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107879
Cc: "18.2" <mesa-stable@lists.freedesktop.org>
2018-09-19 02:00:49 -05:00
Jason Ekstrand
0796c3934e nir/loop_unroll: Re-materialize derefs in use blocks before unrolling
When we're about to re-arrange a bunch of blocks, it's a good idea to
make sure that we don't have deref uses crossing block boundaries.
Otherwise we may end up with a deref going through a phi and that would
be bad.

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Cc: "18.2" <mesa-stable@lists.freedesktop.org>
2018-09-19 01:59:40 -05:00
Jason Ekstrand
7d1d1208c2 nir: Add a small pass to rematerialize derefs per-block
This pass re-materializes deref instructions on a per-block basis to
ensure that every use of a deref occurs in the same block as the
instruction which uses it.

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Cc: "18.2" <mesa-stable@lists.freedesktop.org>
2018-09-19 01:59:40 -05:00
Timothy Arceri
21e34bab09 nir: add loop unroll support for complex wrapper loops
In GLSL IR we cheat with switch statements and simply convert them
into loops with a single iteration. This allowed us to make use of
the existing jump instruction handling provided by the loop handing
code, it also allows dead code to be cleaned up once we have
wrapped the code in a loop.

However using loops in this way created previously unrollable loops
which limits further optimisations. Here we provide a way to unroll
loops that end in a break and have multiple other exits.

All shader-db changes are from the dolphin uber shaders. There is a
small amount of HURT shaders but in general the improvements far
exceed the HURT.

shader-db results IVB:

total instructions in shared programs: 10018187 -> 10016468 (-0.02%)
instructions in affected programs: 104080 -> 102361 (-1.65%)
helped: 36
HURT: 15

total cycles in shared programs: 220065064 -> 154529655 (-29.78%)
cycles in affected programs: 126063017 -> 60527608 (-51.99%)
helped: 51
HURT: 0

total loops in shared programs: 2515 -> 2308 (-8.23%)
loops in affected programs: 903 -> 696 (-22.92%)
helped: 51
HURT: 0

total spills in shared programs: 4370 -> 4124 (-5.63%)
spills in affected programs: 1397 -> 1151 (-17.61%)
helped: 9
HURT: 12

total fills in shared programs: 4581 -> 4419 (-3.54%)
fills in affected programs: 2201 -> 2039 (-7.36%)
helped: 9
HURT: 15

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-09-14 16:07:36 +10:00