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      1 /*
      2  * Copyright  2014 Intel Corporation
      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
     20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
     21  * IN THE SOFTWARE.
     22  *
     23  * Authors:
     24  *    Connor Abbott (cwabbott0 (at) gmail.com)
     25  *
     26  */
     27 
     28 #include "compiler/glsl/ir_uniform.h"
     29 #include "nir.h"
     30 #include "main/config.h"
     31 #include <assert.h>
     32 
     33 /*
     34  * replace atomic counter intrinsics that use a variable with intrinsics
     35  * that directly store the buffer index and byte offset
     36  */
     37 
     38 static bool
     39 lower_instr(nir_intrinsic_instr *instr,
     40             const struct gl_shader_program *shader_program,
     41             nir_shader *shader)
     42 {
     43    nir_intrinsic_op op;
     44    switch (instr->intrinsic) {
     45    case nir_intrinsic_atomic_counter_read_var:
     46       op = nir_intrinsic_atomic_counter_read;
     47       break;
     48 
     49    case nir_intrinsic_atomic_counter_inc_var:
     50       op = nir_intrinsic_atomic_counter_inc;
     51       break;
     52 
     53    case nir_intrinsic_atomic_counter_dec_var:
     54       op = nir_intrinsic_atomic_counter_dec;
     55       break;
     56 
     57    case nir_intrinsic_atomic_counter_add_var:
     58       op = nir_intrinsic_atomic_counter_add;
     59       break;
     60 
     61    case nir_intrinsic_atomic_counter_min_var:
     62       op = nir_intrinsic_atomic_counter_min;
     63       break;
     64 
     65    case nir_intrinsic_atomic_counter_max_var:
     66       op = nir_intrinsic_atomic_counter_max;
     67       break;
     68 
     69    case nir_intrinsic_atomic_counter_and_var:
     70       op = nir_intrinsic_atomic_counter_and;
     71       break;
     72 
     73    case nir_intrinsic_atomic_counter_or_var:
     74       op = nir_intrinsic_atomic_counter_or;
     75       break;
     76 
     77    case nir_intrinsic_atomic_counter_xor_var:
     78       op = nir_intrinsic_atomic_counter_xor;
     79       break;
     80 
     81    case nir_intrinsic_atomic_counter_exchange_var:
     82       op = nir_intrinsic_atomic_counter_exchange;
     83       break;
     84 
     85    case nir_intrinsic_atomic_counter_comp_swap_var:
     86       op = nir_intrinsic_atomic_counter_comp_swap;
     87       break;
     88 
     89    default:
     90       return false;
     91    }
     92 
     93    if (instr->variables[0]->var->data.mode != nir_var_uniform &&
     94        instr->variables[0]->var->data.mode != nir_var_shader_storage &&
     95        instr->variables[0]->var->data.mode != nir_var_shared)
     96       return false; /* atomics passed as function arguments can't be lowered */
     97 
     98    void *mem_ctx = ralloc_parent(instr);
     99    unsigned uniform_loc = instr->variables[0]->var->data.location;
    100 
    101    nir_intrinsic_instr *new_instr = nir_intrinsic_instr_create(mem_ctx, op);
    102    nir_intrinsic_set_base(new_instr,
    103       shader_program->data->UniformStorage[uniform_loc].opaque[shader->info.stage].index);
    104 
    105    nir_load_const_instr *offset_const =
    106       nir_load_const_instr_create(mem_ctx, 1, 32);
    107    offset_const->value.u32[0] = instr->variables[0]->var->data.offset;
    108 
    109    nir_instr_insert_before(&instr->instr, &offset_const->instr);
    110 
    111    nir_ssa_def *offset_def = &offset_const->def;
    112 
    113    nir_deref *tail = &instr->variables[0]->deref;
    114    while (tail->child != NULL) {
    115       nir_deref_array *deref_array = nir_deref_as_array(tail->child);
    116       tail = tail->child;
    117 
    118       unsigned child_array_elements = tail->child != NULL ?
    119          glsl_get_aoa_size(tail->type) : 1;
    120 
    121       offset_const->value.u32[0] += deref_array->base_offset *
    122          child_array_elements * ATOMIC_COUNTER_SIZE;
    123 
    124       if (deref_array->deref_array_type == nir_deref_array_type_indirect) {
    125          nir_load_const_instr *atomic_counter_size =
    126             nir_load_const_instr_create(mem_ctx, 1, 32);
    127          atomic_counter_size->value.u32[0] = child_array_elements * ATOMIC_COUNTER_SIZE;
    128          nir_instr_insert_before(&instr->instr, &atomic_counter_size->instr);
    129 
    130          nir_alu_instr *mul = nir_alu_instr_create(mem_ctx, nir_op_imul);
    131          nir_ssa_dest_init(&mul->instr, &mul->dest.dest, 1, 32, NULL);
    132          mul->dest.write_mask = 0x1;
    133          nir_src_copy(&mul->src[0].src, &deref_array->indirect, mul);
    134          mul->src[1].src.is_ssa = true;
    135          mul->src[1].src.ssa = &atomic_counter_size->def;
    136          nir_instr_insert_before(&instr->instr, &mul->instr);
    137 
    138          nir_alu_instr *add = nir_alu_instr_create(mem_ctx, nir_op_iadd);
    139          nir_ssa_dest_init(&add->instr, &add->dest.dest, 1, 32, NULL);
    140          add->dest.write_mask = 0x1;
    141          add->src[0].src.is_ssa = true;
    142          add->src[0].src.ssa = &mul->dest.dest.ssa;
    143          add->src[1].src.is_ssa = true;
    144          add->src[1].src.ssa = offset_def;
    145          nir_instr_insert_before(&instr->instr, &add->instr);
    146 
    147          offset_def = &add->dest.dest.ssa;
    148       }
    149    }
    150 
    151    new_instr->src[0].is_ssa = true;
    152    new_instr->src[0].ssa = offset_def;
    153 
    154    /* Copy the other sources, if any, from the original instruction to the new
    155     * instruction.
    156     */
    157    for (unsigned i = 0; i < nir_intrinsic_infos[instr->intrinsic].num_srcs; i++)
    158       nir_src_copy(&new_instr->src[i + 1], &instr->src[i], new_instr);
    159 
    160    if (instr->dest.is_ssa) {
    161       nir_ssa_dest_init(&new_instr->instr, &new_instr->dest,
    162                         instr->dest.ssa.num_components, 32, NULL);
    163       nir_ssa_def_rewrite_uses(&instr->dest.ssa,
    164                                nir_src_for_ssa(&new_instr->dest.ssa));
    165    } else {
    166       nir_dest_copy(&new_instr->dest, &instr->dest, mem_ctx);
    167    }
    168 
    169    nir_instr_insert_before(&instr->instr, &new_instr->instr);
    170    nir_instr_remove(&instr->instr);
    171 
    172    return true;
    173 }
    174 
    175 bool
    176 nir_lower_atomics(nir_shader *shader,
    177                   const struct gl_shader_program *shader_program)
    178 {
    179    bool progress = false;
    180 
    181    nir_foreach_function(function, shader) {
    182       if (function->impl) {
    183          nir_foreach_block(block, function->impl) {
    184             nir_foreach_instr_safe(instr, block) {
    185                if (instr->type == nir_instr_type_intrinsic)
    186                   progress |= lower_instr(nir_instr_as_intrinsic(instr),
    187                                           shader_program, shader);
    188             }
    189          }
    190 
    191          nir_metadata_preserve(function->impl, nir_metadata_block_index |
    192                                                nir_metadata_dominance);
    193       }
    194    }
    195 
    196    return progress;
    197 }
    198