agx: Use a dynarray for predecessors

This imposes a fixed ordering, allowing phi sources to be implicitly ordered.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16268>

src/asahi/compiler/agx_compile.c

@@ -130,7 +130,7 @@ agx_block_add_successor(agx_block *block, agx_block *successor)
       }
 
       block->successors[i] = successor;
-      _mesa_set_add(successor->predecessors, block);
+      util_dynarray_append(&successor->predecessors, agx_block *, block);
       return;
    }
 
@@ -1053,8 +1053,7 @@ agx_create_block(agx_context *ctx)
 {
    agx_block *blk = rzalloc(ctx, agx_block);
 
-   blk->predecessors = _mesa_set_create(blk,
-         _mesa_hash_pointer, _mesa_key_pointer_equal);
+   util_dynarray_init(&blk->predecessors, blk);
 
    return blk;
 }

src/asahi/compiler/agx_compiler.h

@@ -351,7 +351,7 @@ typedef struct agx_block {
 
    /* Control flow graph */
    struct agx_block *successors[2];
-   struct set *predecessors;
+   struct util_dynarray predecessors;
    bool unconditional_jumps;
 
    /* Liveness analysis results */
@@ -540,13 +540,7 @@ agx_vec_for_intr(agx_context *ctx, nir_intrinsic_instr *instr)
          _v++, v = *_v) \
 
 #define agx_foreach_predecessor(blk, v) \
-   struct set_entry *_entry_##v; \
-   agx_block *v; \
-   for (_entry_##v = _mesa_set_next_entry(blk->predecessors, NULL), \
-         v = (agx_block *) (_entry_##v ? _entry_##v->key : NULL);  \
-         _entry_##v != NULL; \
-         _entry_##v = _mesa_set_next_entry(blk->predecessors, _entry_##v), \
-         v = (agx_block *) (_entry_##v ? _entry_##v->key : NULL))
+   util_dynarray_foreach(&blk->predecessors, agx_block *, v)
 
 #define agx_foreach_src(ins, v) \
    for (unsigned v = 0; v < ins->nr_srcs; ++v)

src/asahi/compiler/agx_liveness.c

@@ -123,10 +123,9 @@ agx_compute_liveness(agx_context *ctx)
       bool progress = liveness_block_update(blk, words);
 
       /* If we made progress, we need to process the predecessors */
-
-      if (progress || !blk->pass_flags) {
+      if (progress) {
          agx_foreach_predecessor(blk, pred)
-            _mesa_set_add(work_list, pred);
+            _mesa_set_add(work_list, *pred);
       }
 
       /* Use pass flags to communicate that we've visited this block */

src/asahi/compiler/agx_print.c

@@ -208,11 +208,11 @@ agx_print_block(agx_block *block, FILE *fp)
          fprintf(fp, "block%u ", succ->name);
    }
 
-   if (block->predecessors->entries) {
+   if (block->predecessors.size) {
       fprintf(fp, " from");
 
       agx_foreach_predecessor(block, pred)
-         fprintf(fp, " block%u", pred->name);
+         fprintf(fp, " block%u", (*pred)->name);
    }
 
    fprintf(fp, "\n\n");

src/asahi/compiler/agx_register_allocate.c

@@ -102,7 +102,7 @@ agx_ra_assign_local(agx_block *block, uint8_t *ssa_to_reg, uint8_t *ncomps, unsi
 
    agx_foreach_predecessor(block, pred) {
       for (unsigned i = 0; i < BITSET_WORDS(AGX_NUM_REGS); ++i)
-         used_regs[i] |= pred->regs_out[i];
+         used_regs[i] |= (*pred)->regs_out[i];
    }
 
    BITSET_SET(used_regs, 0); // control flow writes r0l

src/asahi/compiler/test/agx_test.h

@@ -40,10 +40,7 @@ agx_test_builder(void *memctx)
    list_inithead(&ctx->blocks);
 
    agx_block *blk = rzalloc(ctx, agx_block);
-
-   blk->predecessors = _mesa_set_create(blk,
-         _mesa_hash_pointer,
-         _mesa_key_pointer_equal);
+   util_dynarray_init(&blk->predecessors, NULL);
 
    list_addtail(&blk->link, &ctx->blocks);
    list_inithead(&blk->instructions);