diff --git a/src/compiler/nir/nir_deref.c b/src/compiler/nir/nir_deref.c index 174c4a3280e..460d3bf4656 100644 --- a/src/compiler/nir/nir_deref.c +++ b/src/compiler/nir/nir_deref.c @@ -697,11 +697,45 @@ opt_remove_cast_cast(nir_deref_instr *cast) return true; } +/** + * Is this casting a struct to a contained struct. + * struct a { struct b field0 }; + * ssa_5 is structa; + * deref_cast (structb *)ssa_5 (function_temp structb); + * converts to + * deref_struct &ssa_5->field0 (function_temp structb); + * This allows subsequent copy propagation to work. + */ static bool -opt_deref_cast(nir_deref_instr *cast) +opt_replace_struct_wrapper_cast(nir_builder *b, nir_deref_instr *cast) +{ + nir_deref_instr *parent = nir_src_as_deref(cast->parent); + if (!parent) + return false; + + if (!glsl_type_is_struct(parent->type)) + return false; + + if (glsl_get_struct_field_offset(parent->type, 0) != 0) + return false; + + if (cast->type != glsl_get_struct_field(parent->type, 0)) + return false; + + nir_deref_instr *replace = nir_build_deref_struct(b, parent, 0); + nir_ssa_def_rewrite_uses(&cast->dest.ssa, nir_src_for_ssa(&replace->dest.ssa)); + nir_deref_instr_remove_if_unused(cast); + return true; +} + +static bool +opt_deref_cast(nir_builder *b, nir_deref_instr *cast) { bool progress; + if (opt_replace_struct_wrapper_cast(b, cast)) + return true; + progress = opt_remove_cast_cast(cast); if (!is_trivial_deref_cast(cast)) return progress; @@ -798,7 +832,7 @@ nir_opt_deref_impl(nir_function_impl *impl) break; case nir_deref_type_cast: - if (opt_deref_cast(deref)) + if (opt_deref_cast(&b, deref)) progress = true; break;