src/compiler/nir/nir_gather_ssa_types.c

   1 /*
   2  * Copyright © 2019 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
  24 #include "nir.h"
  25 #include "util/bitset.h"
  26
  27 static void
  28 set_type(unsigned idx, nir_alu_type type, BITSET_WORD *float_types,
  29          BITSET_WORD *int_types, bool *progress)
  30 {
  31    switch (nir_alu_type_get_base_type(type)) {
  32    case nir_type_bool:
  33    case nir_type_int:
  34    case nir_type_uint:
  35       if (int_types && !BITSET_TEST(int_types, idx)) {
  36          *progress = true;
  37          BITSET_SET(int_types, idx);
  38       }
  39       break;
  40
  41    case nir_type_float:
  42       if (float_types && !BITSET_TEST(float_types, idx)) {
  43          *progress = true;
  44          BITSET_SET(float_types, idx);
  45       }
  46       break;
  47
  48    default:
  49       unreachable("Invalid base nir_alu_type");
  50    }
  51 }
  52
  53 static void
  54 copy_type(unsigned src, unsigned dst, bool src_is_sink,
  55           BITSET_WORD *types, bool *progress)
  56 {
  57    if (!types)
  58       return;
  59
  60    if (BITSET_TEST(types, dst)) {
  61       if (BITSET_TEST(types, src))
  62          return;
  63       BITSET_SET(types, src);
  64       *progress = true;
  65    } else if (BITSET_TEST(types, src) && !src_is_sink) {
  66       BITSET_SET(types, dst);
  67       *progress = true;
  68    }
  69 }
  70
  71 static void
  72 copy_types(nir_src src, nir_dest *dest, BITSET_WORD *float_types,
  73            BITSET_WORD *int_types, bool *progress)
  74 {
  75    bool src_is_sink = nir_src_is_const(src) ||
  76                       src.ssa->parent_instr->type == nir_instr_type_ssa_undef;
  77    copy_type(src.ssa->index, dest->ssa.index, src_is_sink, float_types, progress);
  78    copy_type(src.ssa->index, dest->ssa.index, src_is_sink, int_types, progress);
  79 }
  80
  81 /** Gather up ALU types for SSA values
  82  *
  83  * This pass attempts to determine, for each SSA value, the type of data (int
  84  * or float) that will be stored in it.  The pass is greedy in the sense that
  85  * it just assigns intness or floatness to types without any attempt to sort
  86  * out the interesting cases where a given type may be both.
  87  *
  88  * The output of the pass is a pair of bitsets which has the intness or
  89  * floatness of each SSA value recorded by index.  It is the responsibility of
  90  * the caller to index the SSA defs using nir_index_ssa_defs and allocate the
  91  * bitsets.  Either bitset is allowed to be NULL in which case no data is
  92  * recorded for that type.
  93  */
  94 void
  95 nir_gather_ssa_types(nir_function_impl *impl,
  96                      BITSET_WORD *float_types,
  97                      BITSET_WORD *int_types)
  98 {
  99    bool progress;
 100    do {
 101       progress = false;
 102
 103       nir_foreach_block(block, impl) {
 104          nir_foreach_instr(instr, block) {
 105             switch (instr->type) {
 106             case nir_instr_type_alu: {
 107                nir_alu_instr *alu = nir_instr_as_alu(instr);
 108                assert(alu->dest.dest.is_ssa);
 109                const nir_op_info *info = &nir_op_infos[alu->op];
 110                switch (alu->op) {
 111                case nir_op_mov:
 112                case nir_op_vec2:
 113                case nir_op_vec3:
 114                case nir_op_vec4:
 115                   for (unsigned i = 0; i < info->num_inputs; i++) {
 116                      copy_types(alu->src[i].src, &alu->dest.dest,
 117                                 float_types, int_types, &progress);
 118                   }
 119                   break;
 120
 121                case nir_op_bcsel:
 122                case nir_op_b32csel:
 123                   set_type(alu->src[0].src.ssa->index, nir_type_bool,
 124                            float_types, int_types, &progress);
 125                   copy_types(alu->src[1].src, &alu->dest.dest,
 126                              float_types, int_types, &progress);
 127                   copy_types(alu->src[2].src, &alu->dest.dest,
 128                              float_types, int_types, &progress);
 129                   break;
 130
 131                default:
 132                   for (unsigned i = 0; i < info->num_inputs; i++) {
 133                      assert(alu->src[i].src.is_ssa);
 134                      set_type(alu->src[i].src.ssa->index, info->input_types[i],
 135                               float_types, int_types, &progress);
 136                   }
 137                   set_type(alu->dest.dest.ssa.index, info->output_type,
 138                            float_types, int_types, &progress);
 139                }
 140                break;
 141             }
 142
 143             case nir_instr_type_tex: {
 144                nir_tex_instr *tex = nir_instr_as_tex(instr);
 145                for (unsigned i = 0; i < tex->num_srcs; i++) {
 146                   assert(tex->src[i].src.is_ssa);
 147                   set_type(tex->src[i].src.ssa->index,
 148                            nir_tex_instr_src_type(tex, i),
 149                            float_types, int_types, &progress);
 150                }
 151                assert(tex->dest.is_ssa);
 152                set_type(tex->dest.ssa.index, tex->dest_type,
 153                         float_types, int_types, &progress);
 154                break;
 155             }
 156
 157             case nir_instr_type_intrinsic: {
 158                nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
 159                /* We could go nuts here, but we'll just handle a few simple
 160                 * cases and let everything else be untyped.
 161                 */
 162                switch (intrin->intrinsic) {
 163                case nir_intrinsic_load_deref: {
 164                   nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]);
 165
 166                   assert(intrin->dest.is_ssa);
 167                   set_type(intrin->dest.ssa.index,
 168                            nir_get_nir_type_for_glsl_type(deref->type),
 169                            float_types, int_types, &progress);
 170                   break;
 171                }
 172
 173                case nir_intrinsic_store_deref: {
 174                   nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]);
 175
 176                   assert(intrin->src[1].is_ssa);
 177                   set_type(intrin->src[1].ssa->index,
 178                            nir_get_nir_type_for_glsl_type(deref->type),
 179                            float_types, int_types, &progress);
 180                   break;
 181                }
 182
 183                case nir_intrinsic_load_input:
 184                case nir_intrinsic_load_uniform:
 185                   assert(intrin->dest.is_ssa);
 186                   set_type(intrin->dest.ssa.index,
 187                            nir_intrinsic_type(intrin),
 188                            float_types, int_types, &progress);
 189                   break;
 190
 191                case nir_intrinsic_store_output:
 192                   assert(intrin->src[0].is_ssa);
 193                   set_type(intrin->src[0].ssa->index,
 194                            nir_intrinsic_type(intrin),
 195                            float_types, int_types, &progress);
 196                   break;
 197
 198                default:
 199                   break;
 200                }
 201
 202                /* For the most part, we leave other intrinsics alone.  Most
 203                 * of them don't matter in OpenGL ES 2.0 drivers anyway.
 204                 * However, we should at least check if this is some sort of
 205                 * IO intrinsic and flag it's offset and index sources.
 206                 */
 207                nir_src *offset_src = nir_get_io_offset_src(intrin);
 208                if (offset_src) {
 209                   assert(offset_src->is_ssa);
 210                   set_type(offset_src->ssa->index, nir_type_int,
 211                            float_types, int_types, &progress);
 212                }
 213                break;
 214             }
 215
 216             case nir_instr_type_phi: {
 217                nir_phi_instr *phi = nir_instr_as_phi(instr);
 218                assert(phi->dest.is_ssa);
 219                nir_foreach_phi_src(src, phi) {
 220                   copy_types(src->src, &phi->dest,
 221                              float_types, int_types, &progress);
 222                }
 223                break;
 224             }
 225
 226             default:
 227                break;
 228             }
 229          }
 230       }
 231    } while (progress);
 232 }