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->alu.op)) continue;
  38
  39                 unsigned from = ins->src[1];
  40                 unsigned to = ins->dest;
  41
  42                 if (!(to & PAN_IS_REG))  continue;
  43                 if (from & PAN_IS_REG) continue;
  44
  45                 if (ins->has_inline_constant) continue;
  46                 if (ins->has_constants) continue;
  47                 if (mir_nontrivial_source2_mod(ins)) continue;
  48                 if (mir_nontrivial_outmod(ins)) continue;
  49                 if (!mir_single_use(ctx, from)) continue;
  50
  51                 /* Ensure mask is continguous from 0 */
  52                 if (!(ins->mask & (1 << COMPONENT_X))) continue;
  53                 if (ins->mask & (ins->mask + 1)) continue;
  54
  55                 mir_rewrite_index_dst(ctx, from, ins->dest);
  56                 mir_remove_instruction(ins);
  57                 progress |= true;
  58         }
  59
  60         return progress;
  61 }
  62
  63 bool
  64 midgard_opt_copy_prop(compiler_context *ctx, midgard_block *block)
  65 {
  66         bool progress = false;
  67
  68         mir_foreach_instr_in_block_safe(block, ins) {
  69                 if (ins->type != TAG_ALU_4) continue;
  70                 if (!OP_IS_MOVE(ins->alu.op)) continue;
  71
  72                 unsigned from = ins->src[1];
  73                 unsigned to = ins->dest;
  74
  75                 /* We only work on pure SSA */
  76
  77                 if (to & PAN_IS_REG) continue;
  78                 if (from & PAN_IS_REG) continue;
  79
  80                 /* Constant propagation is not handled here, either */
  81                 if (ins->has_inline_constant) continue;
  82                 if (ins->has_constants) continue;
  83
  84                 /* Modifier propagation is not handled here */
  85                 if (mir_nontrivial_source2_mod_simple(ins)) continue;
  86                 if (mir_nontrivial_outmod(ins)) continue;
  87
  88                 /* Shortened arguments (bias for textures, extra load/store
  89                  * arguments, etc.) do not get a swizzle, only a start
  90                  * component and even that is restricted. Fragment writeout
  91                  * doesn't even get that much */
  92
  93                 bool skip = false;
  94
  95                 mir_foreach_instr_global(ctx, q) {
  96                         bool is_tex = q->type == TAG_TEXTURE_4;
  97                         bool is_ldst = q->type == TAG_LOAD_STORE_4;
  98                         bool is_branch = q->compact_branch;
  99
 100                         if (!(is_tex || is_ldst || is_branch)) continue;
 101
 102                         /* For textures, we get a real swizzle for the
 103                          * coordinate and the content. For stores, we get one.
 104                          * For loads, we get none. */
 105
 106                         unsigned start =
 107                                 is_tex ? 2 :
 108                                 OP_IS_STORE(q->load_store.op) ? 1 : 0;
 109
 110                         mir_foreach_src(q, s) {
 111                                 if ((s >= start) && q->src[s] == to) {
 112                                         skip = true;
 113                                         break;
 114                                 }
 115                         }
 116                 }
 117
 118                 if (skip)
 119                         continue;
 120
 121                 /* We're clear -- rewrite, composing the swizzle */
 122                 mir_rewrite_index_src_swizzle(ctx, to, from, ins->swizzle[1]);
 123                 mir_remove_instruction(ins);
 124                 progress |= true;
 125         }
 126
 127         return progress | midgard_opt_copy_prop_reg(ctx, block);
 128 }