[Mesa-dev] [PATCH 1/2] nir: add nir_opt_move_load_ubo() optimization pass

[Timothy Arceri]

Series:

Reviewed-by: Timothy Arceri <tarceri at itsqueeze.com>

On 09/03/18 01:50, Samuel Pitoiset wrote:
> This pass moves load UBO operations just before their first use,
> loosely based on nir_opt_move_comparisons.
> 
> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
> ---
>   src/compiler/Makefile.sources            |   1 +
>   src/compiler/nir/meson.build             |   1 +
>   src/compiler/nir/nir.h                   |   2 +
>   src/compiler/nir/nir_opt_move_load_ubo.c | 116 +++++++++++++++++++++++++++++++
>   4 files changed, 120 insertions(+)
>   create mode 100644 src/compiler/nir/nir_opt_move_load_ubo.c
> 
> diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources
> index 37340ba809..55143dbc66 100644
> --- a/src/compiler/Makefile.sources
> +++ b/src/compiler/Makefile.sources
> @@ -266,6 +266,7 @@ NIR_FILES = \
>   	nir/nir_opt_intrinsics.c \
>   	nir/nir_opt_loop_unroll.c \
>   	nir/nir_opt_move_comparisons.c \
> +	nir/nir_opt_move_load_ubo.c \
>   	nir/nir_opt_peephole_select.c \
>   	nir/nir_opt_remove_phis.c \
>   	nir/nir_opt_shrink_load.c \
> diff --git a/src/compiler/nir/meson.build b/src/compiler/nir/meson.build
> index a70c236b95..289bb9ea78 100644
> --- a/src/compiler/nir/meson.build
> +++ b/src/compiler/nir/meson.build
> @@ -160,6 +160,7 @@ files_libnir = files(
>     'nir_opt_intrinsics.c',
>     'nir_opt_loop_unroll.c',
>     'nir_opt_move_comparisons.c',
> +  'nir_opt_move_load_ubo.c',
>     'nir_opt_peephole_select.c',
>     'nir_opt_remove_phis.c',
>     'nir_opt_shrink_load.c',
> diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
> index 5b28c727c8..4224da5f82 100644
> --- a/src/compiler/nir/nir.h
> +++ b/src/compiler/nir/nir.h
> @@ -2786,6 +2786,8 @@ bool nir_opt_loop_unroll(nir_shader *shader, nir_variable_mode indirect_mask);
>   
>   bool nir_opt_move_comparisons(nir_shader *shader);
>   
> +bool nir_opt_move_load_ubo(nir_shader *shader);
> +
>   bool nir_opt_peephole_select(nir_shader *shader, unsigned limit);
>   
>   bool nir_opt_remove_phis(nir_shader *shader);
> diff --git a/src/compiler/nir/nir_opt_move_load_ubo.c b/src/compiler/nir/nir_opt_move_load_ubo.c
> new file mode 100644
> index 0000000000..642651152b
> --- /dev/null
> +++ b/src/compiler/nir/nir_opt_move_load_ubo.c
> @@ -0,0 +1,116 @@
> +/*
> + * Copyright © 2016 Intel Corporation
> + * Copyright © 2018 Valve Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#include "nir.h"
> +
> +/**
> + * \file nir_opt_move_load_ubo.c
> + *
> + * This pass moves load UBO operations just before their first use.
> + */
> +static bool
> +move_load_ubo_source(nir_src *src, nir_block *block, nir_instr *before)
> +{
> +   if (!src->is_ssa)
> +      return false;
> +
> +   nir_instr *src_instr = src->ssa->parent_instr;
> +
> +   if (src_instr->block == block &&
> +       src_instr->type == nir_instr_type_intrinsic &&
> +       nir_instr_as_intrinsic(src_instr)->intrinsic == nir_intrinsic_load_ubo) {
> +
> +      exec_node_remove(&src_instr->node);
> +
> +      if (before)
> +         exec_node_insert_node_before(&before->node, &src_instr->node);
> +      else
> +         exec_list_push_tail(&block->instr_list, &src_instr->node);
> +
> +      return true;
> +   }
> +   return false;
> +}
> +
> +static bool
> +move_load_ubo_source_cb(nir_src *src, void *data)
> +{
> +   bool *progress = data;
> +
> +   nir_instr *instr = src->parent_instr;
> +   if (move_load_ubo_source(src, instr->block, instr))
> +      *progress = true;
> +
> +   return true; /* nir_foreach_src should keep going */
> +}
> +
> +static bool
> +move_load_ubo(nir_block *block)
> +{
> +   bool progress = false;
> +
> +   nir_if *iff = nir_block_get_following_if(block);
> +   if (iff) {
> +      progress |= move_load_ubo_source(&iff->condition, block, NULL);
> +   }
> +
> +   nir_foreach_instr_reverse(instr, block) {
> +
> +      if (instr->type == nir_instr_type_phi) {
> +         /* We're going backwards so everything else is a phi too */
> +      } else if (instr->type == nir_instr_type_alu) {
> +         nir_alu_instr *alu = nir_instr_as_alu(instr);
> +
> +         for (int i = nir_op_infos[alu->op].num_inputs - 1; i >= 0; i--) {
> +            progress |= move_load_ubo_source(&alu->src[i].src, block, instr);
> +         }
> +      } else {
> +         nir_foreach_src(instr, move_load_ubo_source_cb, &progress);
> +      }
> +   }
> +
> +   return false;
> +}
> +
> +bool
> +nir_opt_move_load_ubo(nir_shader *shader)
> +{
> +   bool progress = false;
> +
> +   nir_foreach_function(func, shader) {
> +      if (!func->impl)
> +         continue;
> +
> +      nir_foreach_block(block, func->impl) {
> +         if (move_load_ubo(block)) {
> +            nir_metadata_preserve(func->impl, nir_metadata_block_index |
> +                                              nir_metadata_dominance |
> +                                              nir_metadata_live_ssa_defs);
> +            progress = true;
> +         }
> +      }
> +   }
> +
> +   return progress;
> +}
>