src/gallium/drivers/vc4/vc4_opt_small_immediates.c

   1 /*
   2  * Copyright © 2014 Broadcom
   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
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 /**
  25  * @file vc4_opt_small_immediates.c
  26  *
  27  * Turns references to small constant uniform values into small immediates
  28  * fields.
  29  */
  30
  31 #include "vc4_qir.h"
  32 #include "vc4_qpu.h"
  33
  34 static bool debug;
  35
  36 bool
  37 qir_opt_small_immediates(struct vc4_compile *c)
  38 {
  39         bool progress = false;
  40         struct simple_node *node;
  41         struct qinst *defs[c->num_temps];
  42
  43         foreach(node, &c->instructions) {
  44                 struct qinst *inst = (struct qinst *)node;
  45
  46                 if (inst->dst.file == QFILE_TEMP)
  47                         defs[inst->dst.index] = inst;
  48
  49                 /* The small immediate value sits in the raddr B field, so we
  50                  * can't have 2 small immediates in one instruction (unless
  51                  * they're the same value, but that should be optimized away
  52                  * elsewhere).
  53                  */
  54                 bool uses_small_imm = false;
  55                 for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
  56                         if (inst->src[i].file == QFILE_SMALL_IMM)
  57                                 uses_small_imm = true;
  58                 }
  59                 if (uses_small_imm)
  60                         continue;
  61
  62                 for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
  63                         struct qreg src = qir_follow_movs(defs, inst->src[i]);
  64
  65                         if (src.file != QFILE_UNIF ||
  66                             c->uniform_contents[src.index] !=
  67                             QUNIFORM_CONSTANT) {
  68                                 continue;
  69                         }
  70
  71                         if (i == 1 &&
  72                             (inst->op == QOP_TEX_S ||
  73                              inst->op == QOP_TEX_T ||
  74                              inst->op == QOP_TEX_R ||
  75                              inst->op == QOP_TEX_B)) {
  76                                 /* No turning the implicit uniform read into
  77                                  * an immediate.
  78                                  */
  79                                 continue;
  80                         }
  81
  82                         uint32_t imm = c->uniform_data[src.index];
  83                         uint32_t small_imm = qpu_encode_small_immediate(imm);
  84                         if (small_imm == ~0)
  85                                 continue;
  86
  87                         if (debug) {
  88                                 fprintf(stderr, "opt_small_immediate() from: ");
  89                                 qir_dump_inst(c, inst);
  90                                 fprintf(stderr, "\n");
  91                         }
  92                         inst->src[i].file = QFILE_SMALL_IMM;
  93                         inst->src[i].index = imm;
  94                         if (debug) {
  95                                 fprintf(stderr, "to: ");
  96                                 qir_dump_inst(c, inst);
  97                                 fprintf(stderr, "\n");
  98                         }
  99                         progress = true;
 100                         break;
 101                 }
 102         }
 103
 104         return progress;
 105 }