src/panfrost/midgard/midgard_liveness.c

   1 /*
   2  * Copyright (C) 2018-2019 Alyssa Rosenzweig <alyssa@rosenzweig.io>
   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 FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23
  24 #include "compiler.h"
  25
  26 void
  27 mir_liveness_ins_update(uint16_t *live, midgard_instruction *ins, unsigned max)
  28 {
  29         /* live_in[s] = GEN[s] + (live_out[s] - KILL[s]) */
  30
  31         pan_liveness_kill(live, ins->dest, max, mir_bytemask(ins));
  32
  33         mir_foreach_src(ins, src) {
  34                 unsigned node = ins->src[src];
  35                 unsigned bytemask = mir_bytemask_of_read_components(ins, node);
  36
  37                 pan_liveness_gen(live, node, max, bytemask);
  38         }
  39 }
  40
  41 static void
  42 mir_liveness_ins_update_wrap(uint16_t *live, void *ins, unsigned max)
  43 {
  44         mir_liveness_ins_update(live, (midgard_instruction *) ins, max);
  45 }
  46
  47 void
  48 mir_compute_liveness(compiler_context *ctx)
  49 {
  50         /* If we already have fresh liveness, nothing to do */
  51         if (ctx->metadata & MIDGARD_METADATA_LIVENESS)
  52                 return;
  53
  54         mir_compute_temp_count(ctx);
  55         pan_compute_liveness(&ctx->blocks, ctx->temp_count, mir_liveness_ins_update_wrap);
  56
  57         /* Liveness is now valid */
  58         ctx->metadata |= MIDGARD_METADATA_LIVENESS;
  59 }
  60
  61 /* Once liveness data is no longer valid, call this */
  62
  63 void
  64 mir_invalidate_liveness(compiler_context *ctx)
  65 {
  66         /* If we didn't already compute liveness, there's nothing to do */
  67         if (!(ctx->metadata & MIDGARD_METADATA_LIVENESS))
  68                 return;
  69
  70         pan_free_liveness(&ctx->blocks);
  71
  72         /* It's now invalid regardless */
  73         ctx->metadata &= ~MIDGARD_METADATA_LIVENESS;
  74 }
  75
  76 bool
  77 mir_is_live_after(compiler_context *ctx, midgard_block *block, midgard_instruction *start, int src)
  78 {
  79         mir_compute_liveness(ctx);
  80
  81         /* Check whether we're live in the successors */
  82
  83         if (pan_liveness_get(block->base.live_out, src, ctx->temp_count))
  84                 return true;
  85
  86         /* Check the rest of the block for liveness */
  87
  88         mir_foreach_instr_in_block_from(block, ins, mir_next_op(start)) {
  89                 if (mir_has_arg(ins, src))
  90                         return true;
  91         }
  92
  93         return false;
  94 }