Commit Graph

52 Commits

Author SHA1 Message Date
Daniel Schürmann
89a842b2b6 nir/loop_analyze: consider instruction cost of nir_op_flrp
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12061>
2021-08-24 16:10:30 +00:00
Qiang Yu
3c93ebbae5 nir/loop_analyze: skip unsupported induction variable early
Instead of fail in trip count calculation, just don't mark such
kind of variable as induction from the beginning.

Don't bother inline uniform to deal with such kind of variable
either.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11950>
2021-08-19 02:17:35 +00:00
Qiang Yu
0b9639c35d nir/loop_analyze: record induction variables for each loop
For being used by uniform inline lowering pass.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11950>
2021-08-19 02:17:35 +00:00
Qiang Yu
c86ec09d11 nir/loop_analyze: move nir_is_supported_terminator_condition() to header
To be shared with uniform inline.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11950>
2021-08-19 02:17:35 +00:00
Rhys Perry
4832262560 nir/loop_analyze: initialize loop variables on demand
Zero'ing the allocation and calling initialize_ssa_def() for every
ssa def can be expensive. Since we only use a subset of the allocated
variables, initialize it only when needed.

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7511>
2020-11-20 13:57:34 +00:00
Jason Ekstrand
0f94ff8a6a nir: Only force loop unrolling if we know it's a in/out/temp
If we don't know the actual mode then we can't get to the variable so
it's going to be a scratch or other indirect load anyway and we aren't
saving ourselves anything by unrolling the loop.

Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6332>
2020-11-03 22:18:28 +00:00
Rhys Perry
4735c8a522 nir/loop_analyze: adjust force unrolling to only include interesting modes
Instead of force-unrolling any loop which reads an entire array, only do
it for arrays which might be faster to access with constant indices.

Significantly improves compile-time for these CTS tests, which could
previously timeout:
dEQP-VK.spirv_assembly.instruction.graphics.16bit_storage.struct_mixed_types.uniform_buffer_block_geom
dEQP-VK.spirv_assembly.instruction.graphics.16bit_storage.struct_mixed_types.uniform_geom
dEQP-VK.spirv_assembly.instruction.graphics.8bit_storage.struct_mixed_types.storage_buffer_geom
dEQP-VK.spirv_assembly.instruction.graphics.spirv_ids_abuse.lots_ids_geom

fossil-db (Navi):
Totals from 19 (0.01% of 137413) affected shaders:
SGPRs: 1728 -> 1688 (-2.31%)
VGPRs: 1176 -> 1168 (-0.68%)
CodeSize: 198496 -> 136580 (-31.19%)
MaxWaves: 154 -> 156 (+1.30%)
Instrs: 38889 -> 26029 (-33.07%)
Cycles: 446108 -> 1059924 (+137.59%); split: -0.91%, +138.51%
VMEM: 3245 -> 2926 (-9.83%)
SMEM: 850 -> 828 (-2.59%); split: +4.71%, -7.29%
VClause: 549 -> 533 (-2.91%)
SClause: 1810 -> 1522 (-15.91%)
Copies: 2209 -> 1705 (-22.82%); split: -22.95%, +0.14%
Branches: 854 -> 603 (-29.39%); split: -29.86%, +0.47%
PreSGPRs: 1512 -> 1506 (-0.40%); split: -0.53%, +0.13%

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7161>
2020-10-22 12:07:45 +01:00
Karol Herbst
e5899c1e88 nir: rename nir_op_fne to nir_op_fneu
It was always fneu but naming it fne causes confusion from time to time. So
lets rename it. Later we also want to add other unordered and fne, this is
a smaller preparation for that.

Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6377>
2020-08-21 17:26:21 +00:00
Kristian H. Kristensen
de856c6170 nir: Delete unused is_var_constant() helper
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3686>
2020-02-04 06:03:52 +00:00
Samuel Iglesias Gonsálvez
f7d73db353 nir: add support for flushing to zero denorm constants
v2:
- Refactor conditions and shared function (Connor).
- Move code to nir_eval_const_opcode() (Connor).
- Don't flush to zero on fquantize2f16
  From Vulkan spec, VK_KHR_shader_float_controls section:

  "3) Do denorm and rounding mode controls apply to OpSpecConstantOp?

  RESOLVED: Yes, except when the opcode is OpQuantizeToF16."

v3:
- Fix bit size (Connor).
- Fix execution mode on nir_loop_analize (Connor).

v4:
- Adapt after API changes to nir_eval_const_opcode (Andres).

v5:
- Simplify constant_denorm_flush_to_zero (Caio).

v6:
- Adapt after API changes and to use the new constant
  constructors (Andres).
- Replace MAYBE_UNUSED with UNUSED as the first is going
  away (Andres).

v7:
- Adapt to newly added calls (Andres).
- Simplified the auxiliary to flush denorms to zero (Caio).
- Updated to renamed supported capabilities member (Andres).

Signed-off-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Signed-off-by: Andres Gomez <agomez@igalia.com>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com> [v4]
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
2019-09-17 23:39:18 +03:00
Danylo Piliaiev
e71fc7f238 nir/loop_analyze: Treat do{}while(false) loops as 0 iterations
Loops like:

block block_0:
vec1 32 ssa_2 = load_const (0x00000020)
vec1 32 ssa_3 = load_const (0x00000001)
loop {
    vec1 32 ssa_7 = phi block_0: ssa_3, block_4: ssa_9
    vec1 1 ssa_8 = ige ssa_2, ssa_7
    if ssa_8 {
        break
    } else {
    }
    vec1 32 ssa_9 = iadd ssa_7, ssa_1
}

Were treated as having more than 1 iteration and after unrolling
produced wrong results, however such loop will exit during
the first iteration if not unrolled.

So we check if loop will actually loop.

Fixes tests/shaders/glsl-fs-loop-while-false-02.shader_test

Signed-off-by: Danylo Piliaiev <danylo.piliaiev@globallogic.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2019-08-21 11:01:15 +00:00
Jason Ekstrand
7e0fcea727 nir/loop_analyze: Pass nir_const_values directly to helpers
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2019-07-10 00:20:59 +00:00
Jason Ekstrand
ff972c7a3a nir/loop_analyze: Properly handle swizzles in loop conditions
This commit re-plumbs all of nir_loop_analyze to use nir_ssa_scalar for
all intermediate values so that we can properly handle swizzles.  Even
though if conditions are required to be scalars, they may still consume
swizzles so you could have ((a.yzw < b.zzx).xz && c.xx).y == 0 as your
loop termination condition.  The old code would just bail the moment it
saw its first non-zero swizzle but we can now properly chase the scalar
from the if condition to all the way to a, b, and c.

Shader-db results on Kaby Lake:

    total loops in shared programs: 4388 -> 4364 (-0.55%)
    loops in affected programs: 29 -> 5 (-82.76%)
    helped: 29
    HURT: 5

Shader-db results on Haswell:

    total loops in shared programs: 4370 -> 4373 (0.07%)
    loops in affected programs: 2 -> 5 (150.00%)
    helped: 2
    HURT: 5

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2019-07-10 00:20:59 +00:00
Jason Ekstrand
0333649e63 nir/loop_analyze: Refactor detection of limit vars
This commit reworks both get_induction_and_limit_vars() and
try_find_trip_count_vars_in_iand to return true on success and not
modify their output parameters on failure.  This makes their callers
significantly simpler.

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2019-07-10 00:20:59 +00:00
Jason Ekstrand
9a3cb6f5fe nir/loop_analyze: Bail if we encounter swizzles
None of the current code knows what to do with swizzles.  Take the safe
option for now and bail if we see one.  This does have a small shader-db
impact but it is at least safe.

Shader-db results on Kaby Lake:

    total loops in shared programs: 4364 -> 4388 (0.55%)
    loops in affected programs: 5 -> 29 (480.00%)
    helped: 5
    HURT: 29

Shader-db results on Haswell:

    total loops in shared programs: 4373 -> 4370 (-0.07%)
    loops in affected programs: 5 -> 2 (-60.00%)
    helped: 5
    HURT: 2

Fixes: 6772a17acc "nir: Add a loop analysis pass"
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2019-07-10 00:20:59 +00:00
Jason Ekstrand
6455fa9710 nir/loop_analyze: Use new eval_const_* helpers in test_iterations
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2019-07-10 00:20:59 +00:00
Jason Ekstrand
268ad47c11 nir/loop_analyze: Handle bit sizes correctly in calculate_iterations
The current code assumes everything is 32-bit which is very likely true
but not guaranteed by any means.  Instead, use nir_eval_const_opcode to
do the calculations in a bit-size-agnostic way.  We also use the new
constant constructors to build the correct size constants.

Fixes: 6772a17acc "nir: Add a loop analysis pass"
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2019-07-10 00:20:59 +00:00
Jason Ekstrand
9f7ffe41dd nir/loop_analyze: Fix phi-of-identical-alu detection
One issue was that the original version didn't check that swizzles
matched when comparing ALU instructions so it could end up matching
very different instructions.  Using the nir_instrs_equal function from
nir_instr_set.c which we use for CSE should be much more reliable.
Another was that the loop assumes it will only run two iterations which
may not be true.  If there's something which guarantees that this case
only happens for phis after ifs, it wasn't documented.

Fixes: 9e6b39e1d5 "nir: detect more induction variables"
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2019-07-10 00:20:59 +00:00
Karol Herbst
14531d676b nir: make nir_const_value scalar
v2: remove & operator in a couple of memsets
    add some memsets
v3: fixup lima

Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net> (v2)
2019-04-14 22:25:56 +02:00
Karol Herbst
e72beacb95 nir/loop_analyze: use nir_const_value.b for boolean results, not u32
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2019-04-14 22:25:56 +02:00
Caio Marcelo de Oliveira Filho
e5830e1132 nir: Handle array-deref-of-vector case in loop analysis
SPIR-V can produce those for SSBO and UBO access.  Found when testing
the ARB_gl_spirv series.

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2019-03-22 13:50:39 -07:00
Timothy Arceri
427a6fee43 nir: only override previous alu during loop analysis if supported
Users of this function expect alu to be a supported comparision
if the induction variable is not NULL. Since we attempt to
override the return values if the first limit is not a const, we
must make sure we are dealing with a valid comparision before
overriding the alu instruction.

Fixes an unreachable in inverse_comparison() with the game
Assasins Creed Odyssey.

Fixes: 3235a942c1 ("nir: find induction/limit vars in iand instructions")

Acked-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110216
2019-03-21 21:51:21 +11:00
Brian Paul
02c2863df5 nir: silence a couple new compiler warnings
[33/630] Compiling C object 'src/compiler/nir/nir@sta/nir_loop_analyze.c.o'.
../src/compiler/nir/nir_loop_analyze.c: In function ‘try_find_trip_count_vars_in_iand’:
../src/compiler/nir/nir_loop_analyze.c:846:29: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
    if (*ind == NULL || *ind && (*ind)->type != basic_induction ||
                             ^
[85/630] Compiling C object 'src/compiler/nir/nir@sta/nir_opt_loop_unroll.c.o'.
../src/compiler/nir/nir_opt_loop_unroll.c: In function ‘complex_unroll_single_terminator’:
../src/compiler/nir/nir_opt_loop_unroll.c:494:17: warning: unused variable ‘unroll_loc’ [-Wunused-variable]
    nir_cf_node *unroll_loc =
                 ^
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
2019-03-12 14:34:51 +11:00
Timothy Arceri
3235a942c1 nir: find induction/limit vars in iand instructions
This will be used to help find the trip count of loops that look
like the following:

   while (a < x && i < 8) {
      ...
      i++;
   }

Where the NIR will end up looking something like this:

   vec1 32 ssa_1 = load_const (0x00000004 /* 0.000000 */)
   loop {
      ...
      vec1 1 ssa_12 = ilt ssa_225, ssa_11
      vec1 1 ssa_17 = ilt ssa_226, ssa_1
      vec1 1 ssa_18 = iand ssa_12, ssa_17
      vec1 1 ssa_19 = inot ssa_18

      if ssa_19 {
         ...
         break
      } else {
         ...
      }
   }

On RADV this unrolls a bunch of loops in F1-2017 shaders.

Totals from affected shaders:
SGPRS: 4112 -> 4136 (0.58 %)
VGPRS: 4132 -> 4052 (-1.94 %)
Spilled SGPRs: 0 -> 0 (0.00 %)
Spilled VGPRs: 0 -> 0 (0.00 %)
Private memory VGPRs: 0 -> 0 (0.00 %)
Scratch size: 0 -> 0 (0.00 %) dwords per thread
Code Size: 515444 -> 587720 (14.02 %) bytes
LDS: 2 -> 2 (0.00 %) blocks
Max Waves: 194 -> 196 (1.03 %)
Wait states: 0 -> 0 (0.00 %)

It also unrolls a couple of loops in shader-db on radeonsi.

Totals from affected shaders:
SGPRS: 128 -> 128 (0.00 %)
VGPRS: 64 -> 64 (0.00 %)
Spilled SGPRs: 0 -> 0 (0.00 %)
Spilled VGPRs: 0 -> 0 (0.00 %)
Private memory VGPRs: 0 -> 0 (0.00 %)
Scratch size: 0 -> 0 (0.00 %) dwords per thread
Code Size: 6880 -> 9504 (38.14 %) bytes
LDS: 0 -> 0 (0.00 %) blocks
Max Waves: 16 -> 16 (0.00 %)
Wait states: 0 -> 0 (0.00 %)

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2019-03-12 00:52:30 +00:00
Timothy Arceri
67c3478482 nir: pass nir_op to calculate_iterations()
Rather than getting this from the alu instruction this allows us
some flexibility. In the following pass we instead pass the
inverse op.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2019-03-12 00:52:30 +00:00
Timothy Arceri
11e8f8a166 nir: add get_induction_and_limit_vars() helper to loop analysis
This helps make find_trip_count() a little easier to follow but
will also be used by a following patch.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2019-03-12 00:52:30 +00:00
Timothy Arceri
f219f6114d nir: add helper to return inversion op of a comparison
This will be used to help find the trip count of loops that look
like the following:

   while (a < x && i < 8) {
      ...
      i++;
   }

Where the NIR will end up looking something like this:

   vec1 32 ssa_1 = load_const (0x00000004 /* 0.000000 */)
   loop {
      ...
      vec1 1 ssa_12 = ilt ssa_225, ssa_11
      vec1 1 ssa_17 = ilt ssa_226, ssa_1
      vec1 1 ssa_18 = iand ssa_12, ssa_17
      vec1 1 ssa_19 = inot ssa_18

      if ssa_19 {
         ...
         break
      } else {
         ...
      }
   }

So in order to find the trip count we need to find the inverse of
ilt.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2019-03-12 00:52:30 +00:00
Timothy Arceri
090feaacdc nir: simplify the loop analysis trip count code a little
Here we create a helper is_supported_terminator_condition()
and use that rather than embedding all the trip count code
inside a switch.

The new helper will also be used in a following patch.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2019-03-12 00:52:30 +00:00
Timothy Arceri
68ce0ec222 nir: calculate trip count for more loops
This adds support to loop analysis for loops where the induction
variable is compared to the result of min(variable, constant).

For example:

   for (int i = 0; i < imin(x, 4); i++)
      ...

We add a new bool to the loop terminator struct in order to
differentiate terminators with this exit condition.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2019-03-12 00:52:30 +00:00
Timothy Arceri
03a452b7d0 nir: add guess trip count support to loop analysis
This detects an induction variable used as an array index to guess
the trip count of the loop. This enables us to do a partial
unroll of the loop, which can eventually result in the loop being
eliminated.

v2: check if the induction var is used to index more than a single
    array and if so get the size of the smallest array.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2019-03-12 00:52:30 +00:00
Jason Ekstrand
9314084237 nir: Teach loop unrolling about 64-bit instruction lowering
The lowering we do for 64-bit instructions can cause a single NIR ALU
instruction to blow up into hundreds or thousands of instructions
potentially with control flow.  If loop unrolling isn't aware of this,
it can unroll a loop 20 times which contains a nir_op_fsqrt which we
then lower to a full software implementation based on integer math.
Those 20 invocations suddenly get a lot more expensive than NIR loop
unrolling currently expects.  By giving it an approximate estimate
function, we can prevent loop unrolling from going to town when it
shouldn't.

Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2019-03-06 17:24:57 +00:00
Timothy Arceri
6dade5d534 nir: avoid uninitialized variable warning
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109231
2019-01-07 10:57:00 +11:00
Jason Ekstrand
44227453ec nir: Switch to using 1-bit Booleans for almost everything
This is a squash of a few distinct changes:

    glsl,spirv: Generate 1-bit Booleans

    Revert "Use 32-bit opcodes in the NIR producers and optimizations"

    Revert "nir/builder: Generate 32-bit bool opcodes transparently"

    nir/builder: Generate 1-bit Booleans in nir_build_imm_bool

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Tested-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
2018-12-16 21:03:02 +00:00
Jason Ekstrand
80e8dfe9de nir: Rename Boolean-related opcodes to include 32 in the name
This is a squash of a bunch of individual changes:

    nir/builder: Generate 32-bit bool opcodes transparently

    nir/algebraic: Remap Boolean opcodes to the 32-bit variant

    Use 32-bit opcodes in the NIR producers and optimizations

        Generated with a little hand-editing and the following sed commands:

        sed -i 's/nir_op_ball_fequal/nir_op_b32all_fequal/g' **/*.c
        sed -i 's/nir_op_bany_fnequal/nir_op_b32any_fnequal/g' **/*.c
        sed -i 's/nir_op_ball_iequal/nir_op_b32all_iequal/g' **/*.c
        sed -i 's/nir_op_bany_inequal/nir_op_b32any_inequal/g' **/*.c
        sed -i 's/nir_op_\([fiu]lt\)/nir_op_\132/g' **/*.c
        sed -i 's/nir_op_\([fiu]ge\)/nir_op_\132/g' **/*.c
        sed -i 's/nir_op_\([fiu]ne\)/nir_op_\132/g' **/*.c
        sed -i 's/nir_op_\([fiu]eq\)/nir_op_\132/g' **/*.c
        sed -i 's/nir_op_\([fi]\)ne32g/nir_op_\1neg/g' **/*.c
        sed -i 's/nir_op_bcsel/nir_op_b32csel/g' **/*.c

     Use 32-bit opcodes in the NIR back-ends

        Generated with a little hand-editing and the following sed commands:

        sed -i 's/nir_op_ball_fequal/nir_op_b32all_fequal/g' **/*.c
        sed -i 's/nir_op_bany_fnequal/nir_op_b32any_fnequal/g' **/*.c
        sed -i 's/nir_op_ball_iequal/nir_op_b32all_iequal/g' **/*.c
        sed -i 's/nir_op_bany_inequal/nir_op_b32any_inequal/g' **/*.c
        sed -i 's/nir_op_\([fiu]lt\)/nir_op_\132/g' **/*.c
        sed -i 's/nir_op_\([fiu]ge\)/nir_op_\132/g' **/*.c
        sed -i 's/nir_op_\([fiu]ne\)/nir_op_\132/g' **/*.c
        sed -i 's/nir_op_\([fiu]eq\)/nir_op_\132/g' **/*.c
        sed -i 's/nir_op_\([fi]\)ne32g/nir_op_\1neg/g' **/*.c
        sed -i 's/nir_op_bcsel/nir_op_b32csel/g' **/*.c

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Tested-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
2018-12-16 21:03:02 +00:00
Alejandro Piñeiro
c7bdcd67aa nir: remove unused variable
To avoid the following warning:
./src/compiler/nir/nir_loop_analyze.c:807:16: warning: unused variable ‘ns’ [-Wunused-variable]
    nir_shader *ns = impl->function->shader;
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
2018-12-13 16:35:21 +01:00
Timothy Arceri
9e6b39e1d5 nir: detect more induction variables
This allows loop analysis to detect inductions variables that
are incremented in both branches of an if rather than in a main
loop block. For example:

   loop {
      block block_1:
      /* preds: block_0 block_7 */
      vec1 32 ssa_8 = phi block_0: ssa_4, block_7: ssa_20
      vec1 32 ssa_9 = phi block_0: ssa_0, block_7: ssa_4
      vec1 32 ssa_10 = phi block_0: ssa_1, block_7: ssa_4
      vec1 32 ssa_11 = phi block_0: ssa_2, block_7: ssa_21
      vec1 32 ssa_12 = phi block_0: ssa_3, block_7: ssa_22
      vec4 32 ssa_13 = vec4 ssa_12, ssa_11, ssa_10, ssa_9
      vec1 32 ssa_14 = ige ssa_8, ssa_5
      /* succs: block_2 block_3 */
      if ssa_14 {
         block block_2:
         /* preds: block_1 */
         break
         /* succs: block_8 */
      } else {
         block block_3:
         /* preds: block_1 */
         /* succs: block_4 */
      }
      block block_4:
      /* preds: block_3 */
      vec1 32 ssa_15 = ilt ssa_6, ssa_8
      /* succs: block_5 block_6 */
      if ssa_15 {
         block block_5:
         /* preds: block_4 */
         vec1 32 ssa_16 = iadd ssa_8, ssa_7
         vec1 32 ssa_17 = load_const (0x3f800000 /* 1.000000*/)
         /* succs: block_7 */
      } else {
         block block_6:
         /* preds: block_4 */
         vec1 32 ssa_18 = iadd ssa_8, ssa_7
         vec1 32 ssa_19 = load_const (0x3f800000 /* 1.000000*/)
         /* succs: block_7 */
      }
      block block_7:
      /* preds: block_5 block_6 */
      vec1 32 ssa_20 = phi block_5: ssa_16, block_6: ssa_18
      vec1 32 ssa_21 = phi block_5: ssa_17, block_6: ssa_4
      vec1 32 ssa_22 = phi block_5: ssa_4, block_6: ssa_19
      /* succs: block_1 */
   }

Unfortunatly GCM could move the addition out of the if for us
(making this patch unrequired) but we still cannot enable the GCM
pass without regressions.

This unrolls a loop in Rise of The Tomb Raider.

vkpipeline-db results (VEGA):

Totals from affected shaders:
SGPRS: 88 -> 96 (9.09 %)
VGPRS: 56 -> 52 (-7.14 %)
Spilled SGPRs: 0 -> 0 (0.00 %)
Spilled VGPRs: 0 -> 0 (0.00 %)
Private memory VGPRs: 0 -> 0 (0.00 %)
Scratch size: 0 -> 0 (0.00 %) dwords per thread
Code Size: 2168 -> 4560 (110.33 %) bytes
LDS: 0 -> 0 (0.00 %) blocks
Max Waves: 4 -> 4 (0.00 %)
Wait states: 0 -> 0 (0.00 %)

Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=32211
2018-12-13 10:58:35 +11:00
Timothy Arceri
c03d6e61cc nir: reword code comment
Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
2018-12-13 10:58:35 +11:00
Timothy Arceri
48b40380e3 nir: in loop analysis track actual control flow type
This will allow us to improve analysis to find more induction
variables.

Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
2018-12-13 10:58:35 +11:00
Timothy Arceri
721566bddb nir: rework force_unroll_array_access()
Here we rework force_unroll_array_access() so that we can reuse
the induction variable detection in a following patch.

Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
2018-12-13 10:39:51 +11:00
Timothy Arceri
03d7c65ad8 nir: clarify some nit_loop_info member names
Following commits will introduce additional fields such as
guessed_trip_count. Renaming these will help avoid confusion
as our unrolling feature set grows.

Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-12-10 13:59:50 +11:00
Timothy Arceri
de0aee7638 nir: small tidy ups for nir_loop_analyze()
Reviewed-by: Thomas Helland <thomashelland90@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-12-10 13:59:50 +11:00
Timothy Arceri
5a6b04d94b nir: add complex_loop bool to loop info
In order to be sure loop_terminator_list is an accurate
representation of all the jumps in the loop we need to be sure we
didn't encounter any other complex behaviour such as continues,
nested breaks, etc during analysis.

This will be used in the following patch.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-08-29 16:02:05 +10:00
Timothy Arceri
fef6325e58 nir: always attempt to find loop terminators
This will help later patches with unrolling loops that end with a
break i.e. loops the always exit on their first interation.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-08-29 16:02:05 +10:00
Timothy Arceri
463f849097 nir: fix selection of loop terminator when two or more have the same limit
We need to add loop terminators to the list in the order we come
across them otherwise if two or more have the same exit condition
we will select that last one rather than the first one even though
its unreachable.

This fix is for simple unrolls where we only have a single exit
point. When unrolling these type of loops the unreachable
terminators and their unreachable branch are removed prior to
unrolling. Because of the logic change we also switch some
list access in the complex unrolling logic to avoid breakage.

Fixes: 6772a17acc ("nir: Add a loop analysis pass")

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2018-06-30 10:13:03 +10:00
Jason Ekstrand
9800b81ffb nir: Remove deref chain support from analyze_loops
Note that this patch needs to come late in the series since this pass
can be run after any pass that damages nir_metadata_loop_analysis.

Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2018-06-22 21:23:06 -07:00
Jason Ekstrand
414148cdc1 nir: Support deref instructions in loop_analyze
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2018-06-22 20:15:56 -07:00
Rob Clark
d80c342d89 nir: add deref lowering sanity checking
This will be removed at the end of the transition, but add some tracking
plus asserts to help ensure that lowering passes are called at the
correct point (pre or post deref instruction lowering) as passes are
converted and the point where lower_deref_instrs() is called is moved.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Acked-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2018-06-22 20:15:54 -07:00
Timothy Arceri
1098bc5e85 nir: move ends_in_break() helper to nir_loop_analyze.h
We will use the helper while simplifying potential loop terminators
in the following patch.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2018-06-07 11:33:04 +10:00
Matt Turner
d6e2bdfed3 nir: Stop using apostrophes to pluralize.
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
2017-03-23 14:34:43 -07:00
Elie TOURNIER
082d5b1aee nir: Delete unused arg in get_iteration
nir_const_value is not needed in get_iteration

Signed-off-by: Elie Tournier <tournier.elie@gmail.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
2017-02-27 14:35:16 +00:00