src/panfrost/bifrost/bi_liveness.c

   1 /*
   2  * Copyright (C) 2020 Collabora, Ltd.
   3  * Copyright (C) 2018-2019 Alyssa Rosenzweig <alyssa@rosenzweig.io>
   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
  27 void
  28 bi_liveness_ins_update(uint16_t *live, bi_instruction *ins, unsigned max)
  29 {
  30         /* live_in[s] = GEN[s] + (live_out[s] - KILL[s]) */
  31
  32         pan_liveness_kill(live, ins->dest, max, bi_writemask(ins));
  33
  34         bi_foreach_src(ins, src) {
  35                 unsigned node = ins->src[src];
  36                 unsigned bytemask = bi_bytemask_of_read_components(ins, node);
  37
  38                 pan_liveness_gen(live, node, max, bytemask);
  39         }
  40 }
  41
  42 static void
  43 bi_liveness_ins_update_wrap(uint16_t *live, void *ins, unsigned max)
  44 {
  45         bi_liveness_ins_update(live, (bi_instruction *) ins, max);
  46 }
  47
  48 void
  49 bi_compute_liveness(bi_context *ctx)
  50 {
  51         if (ctx->has_liveness)
  52                 return;
  53
  54         pan_compute_liveness(&ctx->blocks, bi_max_temp(ctx), bi_liveness_ins_update_wrap);
  55
  56         ctx->has_liveness = true;
  57 }
  58
  59 /* Once liveness data is no longer valid, call this */
  60
  61 void
  62 bi_invalidate_liveness(bi_context *ctx)
  63 {
  64         if (ctx->has_liveness)
  65                 pan_free_liveness(&ctx->blocks);
  66
  67         ctx->has_liveness = false;
  68 }
  69
  70 bool
  71 bi_is_live_after(bi_context *ctx, bi_block *block, bi_instruction *start, int src)
  72 {
  73         bi_compute_liveness(ctx);
  74
  75         /* Check whether we're live in the successors */
  76
  77         if (pan_liveness_get(block->base.live_out, src, bi_max_temp(ctx)))
  78                 return true;
  79
  80         /* Check the rest of the block for liveness */
  81
  82         bi_foreach_instr_in_block_from(block, ins, bi_next_op(start)) {
  83                 if (bi_has_arg(ins, src))
  84                         return true;
  85         }
  86
  87         return false;
  88 }