diff --git a/src/compiler/nir/nir_loop_analyze.c b/src/compiler/nir/nir_loop_analyze.c index 4a7397d2149..3de45401975 100644 --- a/src/compiler/nir/nir_loop_analyze.c +++ b/src/compiler/nir/nir_loop_analyze.c @@ -245,6 +245,42 @@ compute_induction_information(loop_info_state *state) if (src_var->in_if_branch || src_var->in_nested_loop) break; + /* Detect inductions variables that are incremented in both branches + * of an unnested if rather than in a loop block. + */ + if (is_var_phi(src_var)) { + nir_phi_instr *src_phi = + nir_instr_as_phi(src_var->def->parent_instr); + + nir_op alu_op; + nir_ssa_def *alu_srcs[2] = {0}; + nir_foreach_phi_src(src2, src_phi) { + nir_loop_variable *src_var2 = + get_loop_var(src2->src.ssa, state); + + if (!src_var2->in_if_branch || !is_var_alu(src_var2)) + break; + + nir_alu_instr *alu = + nir_instr_as_alu(src_var2->def->parent_instr); + if (nir_op_infos[alu->op].num_inputs != 2) + break; + + if (alu->src[0].src.ssa == alu_srcs[0] && + alu->src[1].src.ssa == alu_srcs[1] && + alu->op == alu_op) { + /* Both branches perform the same calculation so we can use + * one of them to find the induction variable. + */ + src_var = src_var2; + } else { + alu_srcs[0] = alu->src[0].src.ssa; + alu_srcs[1] = alu->src[1].src.ssa; + alu_op = alu->op; + } + } + } + if (!src_var->in_loop) { biv->def_outside_loop = src_var; } else if (is_var_alu(src_var)) {