nir/loop_analyze: skip unsupported induction variable early

Instead of fail in trip count calculation, just don't mark such
kind of variable as induction from the beginning.

Don't bother inline uniform to deal with such kind of variable
either.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11950>

diff --git a/src/compiler/nir/nir_loop_analyze.c b/src/compiler/nir/nir_loop_analyze.c
index 551680d..65291a7 100644 (file)
--- a/src/compiler/nir/nir_loop_analyze.c
+++ b/src/compiler/nir/nir_loop_analyze.c
@@ -416,6 +416,10 @@ compute_induction_information(loop_info_state *state)
             alu_src_var = src_var;
             nir_alu_instr *alu = nir_instr_as_alu(src_var->def->parent_instr);
 
+            /* Check for unsupported alu operations */
+            if (alu->op != nir_op_iadd && alu->op != nir_op_fadd)
+               break;
+
             if (nir_op_infos[alu->op].num_inputs == 2) {
                for (unsigned i = 0; i < 2; i++) {
                   /* Is one of the operands const or uniform, and the other the phi.
@@ -857,9 +861,8 @@ calculate_iterations(nir_const_value initial, nir_const_value step,
              induction_base_type);
    }
 
-   /* Check for nsupported alu operations */
-   if (alu->op != nir_op_iadd && alu->op != nir_op_fadd)
-      return -1;
+   /* Only variable with these update ops were marked as induction. */
+   assert(alu->op == nir_op_iadd || alu->op == nir_op_fadd);
 
    /* do-while loops can increment the starting value before the condition is
     * checked. e.g.