| /* |
| * Copyright © 2020 Intel Corporation |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| */ |
| |
| #include "nir_builder.h" |
| |
| static bool |
| opt_memcpy_deref_cast(nir_intrinsic_instr *cpy, nir_src *deref_src) |
| { |
| assert(cpy->intrinsic == nir_intrinsic_memcpy_deref); |
| |
| nir_deref_instr *cast = nir_src_as_deref(*deref_src); |
| if (cast == NULL || cast->deref_type != nir_deref_type_cast) |
| return false; |
| |
| /* We always have to replace the source with a deref, not a bare uint |
| * pointer. If it's the first deref in the chain, bail. |
| */ |
| nir_deref_instr *parent = nir_src_as_deref(cast->parent); |
| if (parent == NULL) |
| return false; |
| |
| /* If it has useful alignment information, we want to keep that */ |
| if (cast->cast.align_mul > 0) |
| return false; |
| |
| /* Casts to uint8 or int8 never do us any good; get rid of them */ |
| if (cast->type == glsl_int8_t_type() || |
| cast->type == glsl_uint8_t_type()) { |
| nir_instr_rewrite_src(&cpy->instr, deref_src, |
| nir_src_for_ssa(&parent->dest.ssa)); |
| return true; |
| } |
| |
| int64_t parent_type_size = glsl_get_explicit_size(parent->type, false); |
| if (parent_type_size < 0) |
| return false; |
| |
| if (!nir_src_is_const(cpy->src[2])) |
| return false; |
| |
| /* We don't want to get rid of the cast if the resulting type would be |
| * smaller than the amount of data we're copying. |
| */ |
| if (nir_src_as_uint(cpy->src[2]) < (uint64_t)parent_type_size) |
| return false; |
| |
| nir_instr_rewrite_src(&cpy->instr, deref_src, |
| nir_src_for_ssa(&parent->dest.ssa)); |
| return true; |
| } |
| |
| static bool |
| type_is_tightly_packed(const struct glsl_type *type, unsigned *size_out) |
| { |
| unsigned size = 0; |
| if (glsl_type_is_struct_or_ifc(type)) { |
| unsigned num_fields = glsl_get_length(type); |
| for (unsigned i = 0; i < num_fields; i++) { |
| const struct glsl_struct_field *field = |
| glsl_get_struct_field_data(type, i); |
| |
| if (field->offset < 0 || field->offset != size) |
| return false; |
| |
| unsigned field_size; |
| if (!type_is_tightly_packed(field->type, &field_size)) |
| return false; |
| |
| size = field->offset + field_size; |
| } |
| } else if (glsl_type_is_array_or_matrix(type)) { |
| if (glsl_type_is_unsized_array(type)) |
| return false; |
| |
| unsigned stride = glsl_get_explicit_stride(type); |
| if (stride == 0) |
| return false; |
| |
| const struct glsl_type *elem_type = glsl_get_array_element(type); |
| |
| unsigned elem_size; |
| if (!type_is_tightly_packed(elem_type, &elem_size)) |
| return false; |
| |
| if (elem_size != stride) |
| return false; |
| |
| size = stride * glsl_get_length(type); |
| } else { |
| assert(glsl_type_is_vector_or_scalar(type)); |
| if (glsl_get_explicit_stride(type) > 0) |
| return false; |
| |
| if (glsl_type_is_boolean(type)) |
| return false; |
| |
| size = glsl_get_explicit_size(type, false); |
| } |
| |
| if (size_out) |
| *size_out = size; |
| return true; |
| } |
| |
| static bool |
| try_lower_memcpy(nir_builder *b, nir_intrinsic_instr *cpy, |
| struct set *complex_vars) |
| { |
| nir_deref_instr *dst = nir_src_as_deref(cpy->src[0]); |
| nir_deref_instr *src = nir_src_as_deref(cpy->src[1]); |
| |
| /* A self-copy can always be eliminated */ |
| if (dst == src) { |
| nir_instr_remove(&cpy->instr); |
| return true; |
| } |
| |
| if (!nir_src_is_const(cpy->src[2])) |
| return false; |
| |
| uint64_t size = nir_src_as_uint(cpy->src[2]); |
| if (size == 0) { |
| nir_instr_remove(&cpy->instr); |
| return true; |
| } |
| |
| if (glsl_type_is_vector_or_scalar(src->type) && |
| glsl_type_is_vector_or_scalar(dst->type) && |
| glsl_get_explicit_size(dst->type, false) == size && |
| glsl_get_explicit_size(src->type, false) == size) { |
| b->cursor = nir_instr_remove(&cpy->instr); |
| nir_ssa_def *data = |
| nir_load_deref_with_access(b, src, nir_intrinsic_src_access(cpy)); |
| data = nir_bitcast_vector(b, data, glsl_get_bit_size(dst->type)); |
| assert(data->num_components == glsl_get_vector_elements(dst->type)); |
| nir_store_deref_with_access(b, dst, data, ~0 /* write mask */, |
| nir_intrinsic_dst_access(cpy)); |
| return true; |
| } |
| |
| unsigned type_size; |
| if (dst->type == src->type && |
| type_is_tightly_packed(dst->type, &type_size) && |
| type_size == size) { |
| b->cursor = nir_instr_remove(&cpy->instr); |
| nir_copy_deref_with_access(b, dst, src, |
| nir_intrinsic_dst_access(cpy), |
| nir_intrinsic_src_access(cpy)); |
| return true; |
| } |
| |
| /* If one of the two types is tightly packed and happens to equal the |
| * memcpy size, then we can get the memcpy by casting to that type and |
| * doing a deref copy. |
| * |
| * However, if we blindly apply this logic, we may end up with extra casts |
| * where we don't want them. The whole point of converting memcpy to |
| * copy_deref is in the hopes that nir_opt_copy_prop_vars or |
| * nir_lower_vars_to_ssa will get rid of the copy and those passes don't |
| * handle casts well. Heuristically, only do this optimization if the |
| * tightly packed type is on a deref with nir_var_function_temp so we stick |
| * the cast on the other mode. |
| */ |
| if (dst->modes == nir_var_function_temp && |
| type_is_tightly_packed(dst->type, &type_size) && |
| type_size == size) { |
| b->cursor = nir_instr_remove(&cpy->instr); |
| src = nir_build_deref_cast(b, &src->dest.ssa, |
| src->modes, dst->type, 0); |
| nir_copy_deref_with_access(b, dst, src, |
| nir_intrinsic_dst_access(cpy), |
| nir_intrinsic_src_access(cpy)); |
| return true; |
| } |
| |
| /* If we can get at the variable AND the only complex use of that variable |
| * is as a memcpy destination, then we don't have to care about any empty |
| * space in the variable. In particular, we know that the variable is never |
| * cast to any other type and it's never used as a memcpy source so nothing |
| * can see any padding bytes. This holds even if some other memcpy only |
| * writes to part of the variable. |
| */ |
| if (dst->deref_type == nir_deref_type_var && |
| dst->modes == nir_var_function_temp && |
| _mesa_set_search(complex_vars, dst->var) == NULL && |
| glsl_get_explicit_size(dst->type, false) <= size) { |
| b->cursor = nir_instr_remove(&cpy->instr); |
| src = nir_build_deref_cast(b, &src->dest.ssa, |
| src->modes, dst->type, 0); |
| nir_copy_deref_with_access(b, dst, src, |
| nir_intrinsic_dst_access(cpy), |
| nir_intrinsic_src_access(cpy)); |
| return true; |
| } |
| |
| if (src->modes == nir_var_function_temp && |
| type_is_tightly_packed(src->type, &type_size) && |
| type_size == size) { |
| b->cursor = nir_instr_remove(&cpy->instr); |
| dst = nir_build_deref_cast(b, &dst->dest.ssa, |
| dst->modes, src->type, 0); |
| nir_copy_deref_with_access(b, dst, src, |
| nir_intrinsic_dst_access(cpy), |
| nir_intrinsic_src_access(cpy)); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static bool |
| opt_memcpy_impl(nir_function_impl *impl) |
| { |
| bool progress = false; |
| |
| nir_builder b; |
| nir_builder_init(&b, impl); |
| |
| struct set *complex_vars = _mesa_pointer_set_create(NULL); |
| |
| nir_foreach_block(block, impl) { |
| nir_foreach_instr(instr, block) { |
| if (instr->type != nir_instr_type_deref) |
| continue; |
| |
| nir_deref_instr *deref = nir_instr_as_deref(instr); |
| if (deref->deref_type != nir_deref_type_var) |
| continue; |
| |
| nir_deref_instr_has_complex_use_options opts = |
| nir_deref_instr_has_complex_use_allow_memcpy_dst; |
| if (nir_deref_instr_has_complex_use(deref, opts)) |
| _mesa_set_add(complex_vars, deref->var); |
| } |
| } |
| |
| nir_foreach_block(block, impl) { |
| nir_foreach_instr_safe(instr, block) { |
| if (instr->type != nir_instr_type_intrinsic) |
| continue; |
| |
| nir_intrinsic_instr *cpy = nir_instr_as_intrinsic(instr); |
| if (cpy->intrinsic != nir_intrinsic_memcpy_deref) |
| continue; |
| |
| while (opt_memcpy_deref_cast(cpy, &cpy->src[0])) |
| progress = true; |
| while (opt_memcpy_deref_cast(cpy, &cpy->src[1])) |
| progress = true; |
| |
| if (try_lower_memcpy(&b, cpy, complex_vars)) { |
| progress = true; |
| continue; |
| } |
| } |
| } |
| |
| _mesa_set_destroy(complex_vars, NULL); |
| |
| if (progress) { |
| nir_metadata_preserve(impl, nir_metadata_block_index | |
| nir_metadata_dominance); |
| } else { |
| nir_metadata_preserve(impl, nir_metadata_all); |
| } |
| |
| return progress; |
| } |
| |
| bool |
| nir_opt_memcpy(nir_shader *shader) |
| { |
| bool progress = false; |
| |
| nir_foreach_function(function, shader) { |
| if (function->impl && opt_memcpy_impl(function->impl)) |
| progress = true; |
| } |
| |
| return progress; |
| } |
