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