pco: Move DITR and DITRP fencing from translation to legalization

Signed-off-by: Caius Moldovan <caius.moldovan@imgtec.com>
Reviewed-by: Simon Perretta <simon.perretta@imgtec.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/40724>

src/imagination/pco/pco_internal.h

@@ -1781,6 +1781,7 @@ bool pco_const_imms(pco_shader *shader);
 bool pco_bool(pco_shader *shader);
 bool pco_cf(pco_shader *shader);
 bool pco_dce(pco_shader *shader);
+bool pco_post_ra_legalize(pco_shader *shader);
 bool pco_end(pco_shader *shader);
 bool pco_group_instrs(pco_shader *shader);
 bool pco_index(pco_shader *shader, bool skip_ssa);

src/imagination/pco/pco_ir.c

@@ -55,6 +55,7 @@ void pco_process_ir(pco_ctx *ctx, pco_shader *shader)
    PCO_PASS(_, shader, pco_schedule);
    PCO_PASS(_, shader, pco_legalize);
    PCO_PASS(_, shader, pco_ra);
+   PCO_PASS(_, shader, pco_post_ra_legalize);
    PCO_PASS(_, shader, pco_end);
    PCO_PASS(_, shader, pco_group_instrs);
 

src/imagination/pco/pco_legalize.c

@@ -396,6 +396,25 @@ static bool try_legalize_large_hwreg_offsets(pco_instr *instr,
    return true;
 }
 
+static bool try_legalize_ditr_fence(pco_instr *instr)
+{
+   if (instr->op != PCO_OP_DITR && instr->op != PCO_OP_DITRP)
+      return false;
+
+   pco_builder b =
+      pco_builder_create(instr->parent_func, pco_cursor_before_instr(instr));
+   pco_flush_p0(&b);
+   pco_br_next(&b, .exec_cnd = PCO_EXEC_CND_E1_Z1);
+   pco_br_next(&b, .exec_cnd = PCO_EXEC_CND_E1_Z0);
+
+   b.cursor = pco_cursor_after_instr(instr);
+   pco_flush_p0(&b);
+   pco_br_next(&b, .exec_cnd = PCO_EXEC_CND_E1_Z1);
+   pco_br_next(&b, .exec_cnd = PCO_EXEC_CND_E1_Z0);
+
+   return true;
+}
+
 /**
  * \brief Try to legalizes an instruction.
  *
@@ -441,3 +460,24 @@ bool pco_legalize(pco_shader *shader)
    shader->is_legalized = true;
    return progress;
 }
+
+/**
+ * \brief Post-RA legalization pass.
+ *
+ * \param[in,out] shader PCO shader.
+ * \return True if the pass made progress.
+ */
+bool pco_post_ra_legalize(pco_shader *shader)
+{
+   bool progress = false;
+
+   assert(!shader->is_grouped);
+
+   pco_foreach_func_in_shader (func, shader) {
+      pco_foreach_instr_in_func_safe (instr, func) {
+         progress |= try_legalize_ditr_fence(instr);
+      }
+   }
+
+   return progress;
+}

src/imagination/pco/pco_trans_nir.c

@@ -44,13 +44,6 @@ static pco_block *trans_cf_nodes(trans_ctx *tctx,
                                  struct list_head *cf_node_list,
                                  struct exec_list *nir_cf_node_list);
 
-static inline void pco_fence(pco_builder *b)
-{
-   pco_flush_p0(b);
-   pco_br_next(b, .exec_cnd = PCO_EXEC_CND_E1_Z1);
-   pco_br_next(b, .exec_cnd = PCO_EXEC_CND_E1_Z0);
-}
-
 /**
  * \brief Splits a vector destination into scalar components.
  *
@@ -325,14 +318,8 @@ static inline pco_instr *build_itr(pco_builder *b,
 
    pco_instr_set_itr_mode(instr, itr_mode);
 
-   if (d)
-      pco_fence(b);
-
    pco_builder_insert_instr(b, instr);
 
-   if (d)
-      pco_fence(b);
-
    return instr;
 }