src/panfrost/midgard/midgard_opt_copy_prop.c

   1 /*
   2  * Copyright (C) 2018 Alyssa Rosenzweig
   3  * Copyright (C) 2019 Collabora, Ltd.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  */
  24
  25 #include "compiler.h"
  26 #include "midgard_ops.h"
  27
  28 static bool
  29 mir_nontrivial_outmod(midgard_instruction *ins)
  30 {
  31         bool is_int = midgard_is_integer_op(ins->alu.op);
  32         unsigned mod = ins->alu.outmod;
  33
  34         /* Type conversion is a sort of outmod */
  35         if (ins->alu.dest_override != midgard_dest_override_none)
  36                 return true;
  37
  38         if (is_int)
  39                 return mod != midgard_outmod_int_wrap;
  40         else
  41                 return mod != midgard_outmod_none;
  42 }
  43
  44 bool
  45 midgard_opt_copy_prop(compiler_context *ctx, midgard_block *block)
  46 {
  47         bool progress = false;
  48
  49         mir_foreach_instr_in_block_safe(block, ins) {
  50                 if (ins->type != TAG_ALU_4) continue;
  51                 if (!OP_IS_MOVE(ins->alu.op)) continue;
  52
  53                 unsigned from = ins->ssa_args.src1;
  54                 unsigned to = ins->ssa_args.dest;
  55
  56                 /* We only work on pure SSA */
  57
  58                 if (to >= SSA_FIXED_MINIMUM) continue;
  59                 if (from >= SSA_FIXED_MINIMUM) continue;
  60                 if (to >= ctx->func->impl->ssa_alloc) continue;
  61                 if (from >= ctx->func->impl->ssa_alloc) continue;
  62
  63                 /* Constant propagation is not handled here, either */
  64                 if (ins->ssa_args.inline_constant) continue;
  65                 if (ins->has_constants) continue;
  66
  67                 /* Modifier propagation is not handled here */
  68                 if (mir_nontrivial_source2_mod(ins)) continue;
  69                 if (mir_nontrivial_outmod(ins)) continue;
  70
  71                 /* We're clear -- rewrite */
  72                 mir_rewrite_index_src(ctx, to, from);
  73                 mir_remove_instruction(ins);
  74                 progress |= true;
  75         }
  76
  77         return progress;
  78 }