ir3: Remove loop shared copy check

This is now handled by inserting LCSSA phis similar to how it's handled
in ACO.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28573>

src/freedreno/ir3/ir3.h

@@ -666,7 +666,6 @@ struct ir3_block {
    uint32_t dom_pre_index;
    uint32_t dom_post_index;
 
-   uint32_t loop_id;
    uint32_t loop_depth;
 
 #if MESA_DEBUG

src/freedreno/ir3/ir3_compiler_nir.c

@@ -3769,7 +3769,6 @@ emit_block(struct ir3_context *ctx, nir_block *nblock)
 
    list_addtail(&ctx->block->node, &ctx->ir->block_list);
 
-   ctx->block->loop_id = ctx->loop_id;
    ctx->block->loop_depth = ctx->loop_depth;
 
    /* re-emit addr register in each block if needed: */
@@ -3926,8 +3925,6 @@ static void
 emit_loop(struct ir3_context *ctx, nir_loop *nloop)
 {
    assert(!nir_loop_has_continue_construct(nloop));
-   unsigned old_loop_id = ctx->loop_id;
-   ctx->loop_id = ctx->so->loops + 1;
    ctx->loop_depth++;
 
    struct nir_block *nstart = nir_loop_first_block(nloop);
@@ -3948,14 +3945,12 @@ emit_loop(struct ir3_context *ctx, nir_loop *nloop)
       struct ir3_block *start = get_block(ctx, nstart);
       ir3_JUMP(continue_blk);
       continue_blk->successors[0] = start;
-      continue_blk->loop_id = ctx->loop_id;
       continue_blk->loop_depth = ctx->loop_depth;
       list_addtail(&continue_blk->node, &ctx->ir->block_list);
    }
 
    ctx->so->loops++;
    ctx->loop_depth--;
-   ctx->loop_id = old_loop_id;
 }
 
 static void

src/freedreno/ir3/ir3_context.h

@@ -107,7 +107,6 @@ struct ir3_context {
 
    unsigned num_arrays;
 
-   unsigned loop_id;
    unsigned loop_depth;
 
    /* a common pattern for indirect addressing is to request the

src/freedreno/ir3/ir3_cp.c

@@ -304,22 +304,6 @@ try_swap_mad_two_srcs(struct ir3_instruction *instr, unsigned new_flags)
    return valid_swap;
 }
 
-/* Values that are uniform inside a loop can become divergent outside
- * it if the loop has a divergent trip count. This means that we can't
- * propagate a copy of a shared to non-shared register if it would
- * make the shared reg's live range extend outside of its loop. Users
- * outside the loop would see the value for the thread(s) that last
- * exited the loop, rather than for their own thread.
- */
-static bool
-is_valid_shared_copy(struct ir3_instruction *dst_instr,
-                     struct ir3_instruction *src_instr,
-                     struct ir3_register *src_reg)
-{
-   return !(src_reg->flags & IR3_REG_SHARED) ||
-      dst_instr->block->loop_id == src_instr->block->loop_id;
-}
-
 /**
  * Handle cp for a given src register.  This additionally handles
  * the cases of collapsing immedate/const (which replace the src
@@ -338,9 +322,6 @@ reg_cp(struct ir3_cp_ctx *ctx, struct ir3_instruction *instr,
       struct ir3_register *src_reg = src->srcs[0];
       unsigned new_flags = reg->flags;
 
-      if (!is_valid_shared_copy(instr, src, src_reg))
-         return false;
-
       combine_flags(&new_flags, src);
 
       if (ir3_valid_flags(instr, n, new_flags)) {
@@ -366,9 +347,6 @@ reg_cp(struct ir3_cp_ctx *ctx, struct ir3_instruction *instr,
       struct ir3_register *src_reg = src->srcs[0];
       unsigned new_flags = reg->flags;
 
-      if (!is_valid_shared_copy(instr, src, src_reg))
-         return false;
-
       if (src_reg->flags & IR3_REG_ARRAY)
          return false;