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
  41         list_for_each_entry(struct qinst, inst, &c->instructions, link) {
  42                 /* The small immediate value sits in the raddr B field, so we
  43                  * can't have 2 small immediates in one instruction (unless
  44                  * they're the same value, but that should be optimized away
  45                  * elsewhere).
  46                  */
  47                 bool uses_small_imm = false;
  48                 for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
  49                         if (inst->src[i].file == QFILE_SMALL_IMM)
  50                                 uses_small_imm = true;
  51                 }
  52                 if (uses_small_imm)
  53                         continue;
  54
  55                 for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
  56                         struct qreg src = qir_follow_movs(c, inst->src[i]);
  57
  58                         if (src.file != QFILE_UNIF ||
  59                             c->uniform_contents[src.index] !=
  60                             QUNIFORM_CONSTANT) {
  61                                 continue;
  62                         }
  63
  64                         if (i == 1 &&
  65                             (inst->op == QOP_TEX_S ||
  66                              inst->op == QOP_TEX_T ||
  67                              inst->op == QOP_TEX_R ||
  68                              inst->op == QOP_TEX_B)) {
  69                                 /* No turning the implicit uniform read into
  70                                  * an immediate.
  71                                  */
  72                                 continue;
  73                         }
  74
  75                         if (qir_src_needs_a_file(inst))
  76                                 continue;
  77
  78                         uint32_t imm = c->uniform_data[src.index];
  79                         uint32_t small_imm = qpu_encode_small_immediate(imm);
  80                         if (small_imm == ~0)
  81                                 continue;
  82
  83                         if (debug) {
  84                                 fprintf(stderr, "opt_small_immediate() from: ");
  85                                 qir_dump_inst(c, inst);
  86                                 fprintf(stderr, "\n");
  87                         }
  88                         inst->src[i].file = QFILE_SMALL_IMM;
  89                         inst->src[i].index = imm;
  90                         if (debug) {
  91                                 fprintf(stderr, "to: ");
  92                                 qir_dump_inst(c, inst);
  93                                 fprintf(stderr, "\n");
  94                         }
  95                         progress = true;
  96                         break;
  97                 }
  98         }
  99
 100         return progress;
 101 }