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 /* Special case for copypropagating the results of vectors */
  29
  30 static bool
  31 midgard_opt_copy_prop_reg(compiler_context *ctx, midgard_block *block)
  32 {
  33         bool progress = false;
  34
  35         mir_foreach_instr_in_block_safe(block, ins) {
  36                 if (ins->type != TAG_ALU_4) continue;
  37                 if (!OP_IS_MOVE(ins->op)) continue;
  38                 if (ins->is_pack) continue;
  39
  40                 unsigned from = ins->src[1];
  41                 unsigned to = ins->dest;
  42
  43                 if (!(to & PAN_IS_REG))  continue;
  44                 if (from & PAN_IS_REG) continue;
  45
  46                 if (ins->has_inline_constant) continue;
  47                 if (ins->has_constants) continue;
  48                 if (mir_nontrivial_mod(ins, 1, true)) continue;
  49                 if (mir_nontrivial_outmod(ins)) continue;
  50                 if (!mir_single_use(ctx, from)) continue;
  51
  52                 /* Ensure mask is continguous from 0 */
  53                 if (!(ins->mask & (1 << COMPONENT_X))) continue;
  54                 if (ins->mask & (ins->mask + 1)) continue;
  55
  56                 mir_rewrite_index_dst(ctx, from, ins->dest);
  57                 mir_remove_instruction(ins);
  58                 progress |= true;
  59         }
  60
  61         return progress;
  62 }
  63
  64 bool
  65 midgard_opt_copy_prop(compiler_context *ctx, midgard_block *block)
  66 {
  67         bool progress = false;
  68
  69         mir_foreach_instr_in_block_safe(block, ins) {
  70                 if (ins->type != TAG_ALU_4) continue;
  71                 if (!OP_IS_MOVE(ins->op)) continue;
  72                 if (ins->is_pack) continue;
  73
  74                 unsigned from = ins->src[1];
  75                 unsigned to = ins->dest;
  76
  77                 /* We only work on pure SSA */
  78
  79                 if (to & PAN_IS_REG) continue;
  80                 if (from & PAN_IS_REG) continue;
  81
  82                 /* Constant propagation is not handled here, either */
  83                 if (ins->has_inline_constant) continue;
  84                 if (ins->has_constants) continue;
  85
  86                 /* Modifier propagation is not handled here */
  87                 if (mir_nontrivial_mod(ins, 1, false)) continue;
  88                 if (mir_nontrivial_outmod(ins)) continue;
  89
  90                 /* Shortened arguments (bias for textures, extra load/store
  91                  * arguments, etc.) do not get a swizzle, only a start
  92                  * component and even that is restricted. Fragment writeout
  93                  * doesn't even get that much */
  94
  95                 bool skip = false;
  96
  97                 mir_foreach_instr_global(ctx, q) {
  98                         bool is_tex = q->type == TAG_TEXTURE_4;
  99                         bool is_ldst = q->type == TAG_LOAD_STORE_4;
 100                         bool is_branch = q->compact_branch;
 101
 102                         if (!(is_tex || is_ldst || is_branch)) continue;
 103
 104                         /* For textures, we get a real swizzle for the
 105                          * coordinate and the content. For stores, we get one.
 106                          * For loads, we get none. */
 107
 108                         unsigned start =
 109                                 is_tex ? 2 :
 110                                 OP_IS_STORE(q->op) ? 1 : 0;
 111
 112                         mir_foreach_src(q, s) {
 113                                 if ((s >= start) && q->src[s] == to) {
 114                                         skip = true;
 115                                         break;
 116                                 }
 117                         }
 118                 }
 119
 120                 if (skip)
 121                         continue;
 122
 123                 if (ctx->blend_src1 == to)
 124                         ctx->blend_src1 = from;
 125
 126                 /* We're clear -- rewrite, composing the swizzle */
 127                 mir_rewrite_index_src_swizzle(ctx, to, from, ins->swizzle[1]);
 128                 mir_remove_instruction(ins);
 129                 progress |= true;
 130         }
 131
 132         return progress | midgard_opt_copy_prop_reg(ctx, block);
 133 }