src/gallium/drivers/freedreno/ir3/ir3_visitor.h

   1 /* -*- mode: C; c-file-style: "k&r"; tab-width 4; indent-tabs-mode: t; -*- */
   2
   3 /*
   4  * Copyright (C) 2014 Rob Clark <robclark@freedesktop.org>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the next
  14  * paragraph) shall be included in all copies or substantial portions of the
  15  * Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  *
  25  * Authors:
  26  *    Rob Clark <robclark@freedesktop.org>
  27  */
  28
  29 #ifndef IR3_VISITOR_H_
  30 #define IR3_VISITOR_H_
  31
  32 /**
  33  * Visitor which follows dst to src relationships between instructions,
  34  * first visiting the dst (writer) instruction, followed by src (reader)
  35  * instruction(s).
  36  *
  37  * TODO maybe we want multiple different visitors to walk the
  38  * graph in different ways?
  39  */
  40
  41 struct ir3_visitor;
  42
  43 typedef void (*ir3_visit_instr_func)(struct ir3_visitor *v,
  44                 struct ir3_instruction *instr);
  45
  46 typedef void (*ir3_visit_reg_func)(struct ir3_visitor *v,
  47                 struct ir3_instruction *instr, struct ir3_register *reg);
  48
  49 struct ir3_visitor_funcs {
  50         ir3_visit_instr_func instr;  // TODO do we need??
  51
  52         ir3_visit_reg_func dst_shader_input;
  53         ir3_visit_reg_func dst_block_input;
  54         ir3_visit_reg_func dst_fanout;
  55         ir3_visit_reg_func dst_fanin;
  56         ir3_visit_reg_func dst;
  57
  58         ir3_visit_reg_func src_block_input;
  59         ir3_visit_reg_func src_fanout;
  60         ir3_visit_reg_func src_fanin;
  61         ir3_visit_reg_func src;
  62 };
  63
  64 struct ir3_visitor {
  65         const struct ir3_visitor_funcs *funcs;
  66         bool error;
  67 };
  68
  69 #include "util/u_debug.h"
  70
  71 static void visit_instr_dst(struct ir3_visitor *v,
  72                 struct ir3_instruction *instr)
  73 {
  74         struct ir3_register *reg = instr->regs[0];
  75
  76         if (is_meta(instr)) {
  77                 switch (instr->opc) {
  78                 case OPC_META_INPUT:
  79                         if (instr->regs_count == 1)
  80                                 v->funcs->dst_shader_input(v, instr, reg);
  81                         else
  82                                 v->funcs->dst_block_input(v, instr, reg);
  83                         return;
  84                 case OPC_META_FO:
  85                         v->funcs->dst_fanout(v, instr, reg);
  86                         return;
  87                 case OPC_META_FI:
  88                         v->funcs->dst_fanin(v, instr, reg);
  89                         return;
  90                 default:
  91                         break;
  92
  93                 }
  94         }
  95
  96         v->funcs->dst(v, instr, reg);
  97 }
  98
  99 static void visit_instr_src(struct ir3_visitor *v,
 100                 struct ir3_instruction *instr, struct ir3_register *reg)
 101 {
 102         if (is_meta(instr)) {
 103                 switch (instr->opc) {
 104                 case OPC_META_INPUT:
 105                         /* shader-input does not have a src, only block input: */
 106                         debug_assert(instr->regs_count == 2);
 107                         v->funcs->src_block_input(v, instr, reg);
 108                         return;
 109                 case OPC_META_FO:
 110                         v->funcs->src_fanout(v, instr, reg);
 111                         return;
 112                 case OPC_META_FI:
 113                         v->funcs->src_fanin(v, instr, reg);
 114                         return;
 115                 default:
 116                         break;
 117
 118                 }
 119         }
 120
 121         v->funcs->src(v, instr, reg);
 122 }
 123
 124 static void ir3_visit_instr(struct ir3_visitor *v,
 125                 struct ir3_instruction *instr)
 126 {
 127         struct ir3_instruction *n;
 128
 129         /* visit instruction that assigns value: */
 130         if (instr->regs_count > 0)
 131                 visit_instr_dst(v, instr);
 132
 133         /* and of any following instructions which read that value: */
 134         n = instr->next;
 135         while (n && !v->error) {
 136                 unsigned i;
 137
 138                 for (i = 1; i < n->regs_count; i++) {
 139                         struct ir3_register *reg = n->regs[i];
 140                         if ((reg->flags & IR3_REG_SSA) && (reg->instr == instr))
 141                                 visit_instr_src(v, n, reg);
 142                 }
 143
 144                 n = n->next;
 145         }
 146 }
 147
 148 static void ir3_visit_reg(struct ir3_visitor *v,
 149                 struct ir3_instruction *instr, struct ir3_register *reg)
 150 {
 151         /* no-op */
 152 }
 153
 154 #endif /* IR3_VISITOR_H_ */