src/freedreno/ir3/ir3_nir_analyze_ubo_ranges.c

   1 /*
   2  * Copyright © 2019 Google, Inc.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23
  24 #include "ir3_nir.h"
  25 #include "compiler/nir/nir.h"
  26 #include "compiler/nir/nir_builder.h"
  27 #include "util/u_dynarray.h"
  28 #include "mesa/main/macros.h"
  29
  30 struct ir3_ubo_analysis_state {
  31         unsigned lower_count;
  32 };
  33
  34 static void
  35 lower_ubo_load_to_uniform(nir_intrinsic_instr *instr, nir_builder *b,
  36                                                   struct ir3_ubo_analysis_state *state)
  37 {
  38         /* We don't lower dynamic block index UBO loads to load_uniform, but we
  39          * could probably with some effort determine a block stride in number of
  40          * registers.
  41          */
  42         if (!nir_src_is_const(instr->src[0]))
  43                 return;
  44
  45         const uint32_t block = nir_src_as_uint(instr->src[0]);
  46         if (block > 0)
  47                 return;
  48
  49         b->cursor = nir_before_instr(&instr->instr);
  50
  51         nir_ssa_def *ubo_offset = nir_ssa_for_src(b, instr->src[1], 1);
  52         nir_ssa_def *uniform_offset = ir3_nir_try_propagate_bit_shift(b, ubo_offset, -2);
  53         if (uniform_offset == NULL)
  54                 uniform_offset = nir_ushr(b, ubo_offset, nir_imm_int(b, 2));
  55
  56         nir_intrinsic_instr *uniform =
  57                 nir_intrinsic_instr_create(b->shader, nir_intrinsic_load_uniform);
  58         uniform->num_components = instr->num_components;
  59         uniform->src[0] = nir_src_for_ssa(uniform_offset);
  60         nir_ssa_dest_init(&uniform->instr, &uniform->dest,
  61                                           uniform->num_components, instr->dest.ssa.bit_size,
  62                                           instr->dest.ssa.name);
  63         nir_builder_instr_insert(b, &uniform->instr);
  64         nir_ssa_def_rewrite_uses(&instr->dest.ssa,
  65                                                          nir_src_for_ssa(&uniform->dest.ssa));
  66
  67         nir_instr_remove(&instr->instr);
  68
  69         state->lower_count++;
  70 }
  71
  72 bool
  73 ir3_nir_analyze_ubo_ranges(nir_shader *nir, struct ir3_shader *shader)
  74 {
  75         struct ir3_ubo_analysis_state state = { 0 };
  76
  77         nir_foreach_function(function, nir) {
  78                 if (function->impl) {
  79                         nir_builder builder;
  80                         nir_builder_init(&builder, function->impl);
  81                         nir_foreach_block(block, function->impl) {
  82                                 nir_foreach_instr_safe(instr, block) {
  83                                         if (instr->type == nir_instr_type_intrinsic &&
  84                                                 nir_instr_as_intrinsic(instr)->intrinsic == nir_intrinsic_load_ubo)
  85                                                 lower_ubo_load_to_uniform(nir_instr_as_intrinsic(instr), &builder, &state);
  86                                 }
  87                         }
  88
  89                         nir_metadata_preserve(function->impl, nir_metadata_block_index |
  90                                                                   nir_metadata_dominance);
  91                 }
  92         }
  93
  94         return state.lower_count > 0;
  95 }