src/panfrost/midgard/mir.c

   1 /*
   2  * Copyright (C) 2019 Alyssa Rosenzweig <alyssa@rosenzweig.io>
   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 "compiler.h"
  25 #include "midgard_ops.h"
  26
  27 void mir_rewrite_index_src_single(midgard_instruction *ins, unsigned old, unsigned new)
  28 {
  29         if (ins->ssa_args.src0 == old)
  30                 ins->ssa_args.src0 = new;
  31
  32         if (ins->ssa_args.src1 == old &&
  33             !ins->ssa_args.inline_constant)
  34                 ins->ssa_args.src1 = new;
  35 }
  36
  37
  38 void
  39 mir_rewrite_index_src(compiler_context *ctx, unsigned old, unsigned new)
  40 {
  41         mir_foreach_instr_global(ctx, ins) {
  42                 mir_rewrite_index_src_single(ins, old, new);
  43         }
  44 }
  45
  46 void
  47 mir_rewrite_index_src_tag(compiler_context *ctx, unsigned old, unsigned new, unsigned tag)
  48 {
  49         mir_foreach_instr_global(ctx, ins) {
  50                 if (ins->type != tag)
  51                         continue;
  52
  53                 mir_rewrite_index_src_single(ins, old, new);
  54         }
  55 }
  56
  57
  58
  59 void
  60 mir_rewrite_index_dst(compiler_context *ctx, unsigned old, unsigned new)
  61 {
  62         mir_foreach_instr_global(ctx, ins) {
  63                 if (ins->ssa_args.dest == old)
  64                         ins->ssa_args.dest = new;
  65         }
  66 }
  67
  68 void
  69 mir_rewrite_index_dst_tag(compiler_context *ctx, unsigned old, unsigned new, unsigned tag)
  70 {
  71         mir_foreach_instr_global(ctx, ins) {
  72                 if (ins->type != tag)
  73                         continue;
  74
  75                 if (ins->ssa_args.dest == old)
  76                         ins->ssa_args.dest = new;
  77         }
  78 }
  79
  80
  81
  82 void
  83 mir_rewrite_index(compiler_context *ctx, unsigned old, unsigned new)
  84 {
  85         mir_rewrite_index_src(ctx, old, new);
  86         mir_rewrite_index_dst(ctx, old, new);
  87 }
  88
  89 unsigned
  90 mir_use_count(compiler_context *ctx, unsigned value)
  91 {
  92         unsigned used_count = 0;
  93
  94         mir_foreach_instr_global(ctx, ins) {
  95                 if (mir_has_arg(ins, value))
  96                         ++used_count;
  97         }
  98
  99         return used_count;
 100 }
 101
 102 /* Checks if a value is used only once (or totally dead), which is an important
 103  * heuristic to figure out if certain optimizations are Worth It (TM) */
 104
 105 bool
 106 mir_single_use(compiler_context *ctx, unsigned value)
 107 {
 108         return mir_use_count(ctx, value) <= 1;
 109 }
 110
 111 bool
 112 mir_nontrivial_mod(midgard_vector_alu_src src, bool is_int, unsigned mask)
 113 {
 114         /* abs or neg */
 115         if (!is_int && src.mod) return true;
 116
 117         /* Other int mods don't matter in isolation */
 118         if (is_int && src.mod == midgard_int_shift) return true;
 119
 120         /* size-conversion */
 121         if (src.half) return true;
 122
 123         /* swizzle */
 124         for (unsigned c = 0; c < 4; ++c) {
 125                 if (!(mask & (1 << c))) continue;
 126                 if (((src.swizzle >> (2*c)) & 3) != c) return true;
 127         }
 128
 129         return false;
 130 }
 131
 132 bool
 133 mir_nontrivial_source2_mod(midgard_instruction *ins)
 134 {
 135         bool is_int = midgard_is_integer_op(ins->alu.op);
 136
 137         midgard_vector_alu_src src2 =
 138                 vector_alu_from_unsigned(ins->alu.src2);
 139
 140         return mir_nontrivial_mod(src2, is_int, ins->mask);
 141 }
 142
 143 /* Checks if an index will be used as a special register -- basically, if we're
 144  * used as the input to a non-ALU op */
 145
 146 bool
 147 mir_special_index(compiler_context *ctx, unsigned idx)
 148 {
 149         mir_foreach_instr_global(ctx, ins) {
 150                 bool is_ldst = ins->type == TAG_LOAD_STORE_4;
 151                 bool is_tex = ins->type == TAG_TEXTURE_4;
 152
 153                 if (!(is_ldst || is_tex))
 154                         continue;
 155
 156                 if (mir_has_arg(ins, idx))
 157                         return true;
 158         }
 159
 160         return false;
 161 }