| /* |
| * Copyright © 2018 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.h" |
| #include "nir_builder.h" |
| #include "nir_deref.h" |
| #include "util/hash_table.h" |
| |
| static bool |
| is_trivial_deref_cast(nir_deref_instr *cast) |
| { |
| nir_deref_instr *parent = nir_src_as_deref(cast->parent); |
| if (!parent) |
| return false; |
| |
| return cast->mode == parent->mode && |
| cast->type == parent->type && |
| cast->dest.ssa.num_components == parent->dest.ssa.num_components && |
| cast->dest.ssa.bit_size == parent->dest.ssa.bit_size; |
| } |
| |
| void |
| nir_deref_path_init(nir_deref_path *path, |
| nir_deref_instr *deref, void *mem_ctx) |
| { |
| assert(deref != NULL); |
| |
| /* The length of the short path is at most ARRAY_SIZE - 1 because we need |
| * room for the NULL terminator. |
| */ |
| static const int max_short_path_len = ARRAY_SIZE(path->_short_path) - 1; |
| |
| int count = 0; |
| |
| nir_deref_instr **tail = &path->_short_path[max_short_path_len]; |
| nir_deref_instr **head = tail; |
| |
| *tail = NULL; |
| for (nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) { |
| if (d->deref_type == nir_deref_type_cast && is_trivial_deref_cast(d)) |
| continue; |
| count++; |
| if (count <= max_short_path_len) |
| *(--head) = d; |
| } |
| |
| if (count <= max_short_path_len) { |
| /* If we're under max_short_path_len, just use the short path. */ |
| path->path = head; |
| goto done; |
| } |
| |
| #ifndef NDEBUG |
| /* Just in case someone uses short_path by accident */ |
| for (unsigned i = 0; i < ARRAY_SIZE(path->_short_path); i++) |
| path->_short_path[i] = (void *)(uintptr_t)0xdeadbeef; |
| #endif |
| |
| path->path = ralloc_array(mem_ctx, nir_deref_instr *, count + 1); |
| head = tail = path->path + count; |
| *tail = NULL; |
| for (nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) { |
| if (d->deref_type == nir_deref_type_cast && is_trivial_deref_cast(d)) |
| continue; |
| *(--head) = d; |
| } |
| |
| done: |
| assert(head == path->path); |
| assert(tail == head + count); |
| assert(*tail == NULL); |
| } |
| |
| void |
| nir_deref_path_finish(nir_deref_path *path) |
| { |
| if (path->path < &path->_short_path[0] || |
| path->path > &path->_short_path[ARRAY_SIZE(path->_short_path) - 1]) |
| ralloc_free(path->path); |
| } |
| |
| /** |
| * Recursively removes unused deref instructions |
| */ |
| bool |
| nir_deref_instr_remove_if_unused(nir_deref_instr *instr) |
| { |
| bool progress = false; |
| |
| for (nir_deref_instr *d = instr; d; d = nir_deref_instr_parent(d)) { |
| /* If anyone is using this deref, leave it alone */ |
| assert(d->dest.is_ssa); |
| if (!list_is_empty(&d->dest.ssa.uses)) |
| break; |
| |
| nir_instr_remove(&d->instr); |
| progress = true; |
| } |
| |
| return progress; |
| } |
| |
| bool |
| nir_deref_instr_has_indirect(nir_deref_instr *instr) |
| { |
| while (instr->deref_type != nir_deref_type_var) { |
| /* Consider casts to be indirects */ |
| if (instr->deref_type == nir_deref_type_cast) |
| return true; |
| |
| if ((instr->deref_type == nir_deref_type_array || |
| instr->deref_type == nir_deref_type_ptr_as_array) && |
| !nir_src_is_const(instr->arr.index)) |
| return true; |
| |
| instr = nir_deref_instr_parent(instr); |
| } |
| |
| return false; |
| } |
| |
| bool |
| nir_deref_instr_is_known_out_of_bounds(nir_deref_instr *instr) |
| { |
| for (; instr; instr = nir_deref_instr_parent(instr)) { |
| if (instr->deref_type == nir_deref_type_array && |
| nir_src_is_const(instr->arr.index) && |
| nir_src_as_uint(instr->arr.index) >= |
| glsl_get_length(nir_deref_instr_parent(instr)->type)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| bool |
| nir_deref_instr_has_complex_use(nir_deref_instr *deref) |
| { |
| nir_foreach_use(use_src, &deref->dest.ssa) { |
| nir_instr *use_instr = use_src->parent_instr; |
| |
| switch (use_instr->type) { |
| case nir_instr_type_deref: { |
| nir_deref_instr *use_deref = nir_instr_as_deref(use_instr); |
| |
| /* A var deref has no sources */ |
| assert(use_deref->deref_type != nir_deref_type_var); |
| |
| /* If a deref shows up in an array index or something like that, it's |
| * a complex use. |
| */ |
| if (use_src != &use_deref->parent) |
| return true; |
| |
| /* Anything that isn't a basic struct or array deref is considered to |
| * be a "complex" use. In particular, we don't allow ptr_as_array |
| * because we assume that opt_deref will turn any non-complex |
| * ptr_as_array derefs into regular array derefs eventually so passes |
| * which only want to handle simple derefs will pick them up in a |
| * later pass. |
| */ |
| if (use_deref->deref_type != nir_deref_type_struct && |
| use_deref->deref_type != nir_deref_type_array_wildcard && |
| use_deref->deref_type != nir_deref_type_array) |
| return true; |
| |
| if (nir_deref_instr_has_complex_use(use_deref)) |
| return true; |
| |
| continue; |
| } |
| |
| case nir_instr_type_intrinsic: { |
| nir_intrinsic_instr *use_intrin = nir_instr_as_intrinsic(use_instr); |
| switch (use_intrin->intrinsic) { |
| case nir_intrinsic_load_deref: |
| assert(use_src == &use_intrin->src[0]); |
| continue; |
| |
| case nir_intrinsic_copy_deref: |
| assert(use_src == &use_intrin->src[0] || |
| use_src == &use_intrin->src[1]); |
| continue; |
| |
| case nir_intrinsic_store_deref: |
| /* A use in src[1] of a store means we're taking that pointer and |
| * writing it to a variable. Because we have no idea who will |
| * read that variable and what they will do with the pointer, it's |
| * considered a "complex" use. A use in src[0], on the other |
| * hand, is a simple use because we're just going to dereference |
| * it and write a value there. |
| */ |
| if (use_src == &use_intrin->src[0]) |
| continue; |
| return true; |
| |
| default: |
| return true; |
| } |
| unreachable("Switch default failed"); |
| } |
| |
| default: |
| return true; |
| } |
| } |
| |
| nir_foreach_if_use(use, &deref->dest.ssa) |
| return true; |
| |
| return false; |
| } |
| |
| static unsigned |
| type_scalar_size_bytes(const struct glsl_type *type) |
| { |
| assert(glsl_type_is_vector_or_scalar(type) || |
| glsl_type_is_matrix(type)); |
| return glsl_type_is_boolean(type) ? 4 : glsl_get_bit_size(type) / 8; |
| } |
| |
| unsigned |
| nir_deref_instr_array_stride(nir_deref_instr *deref) |
| { |
| switch (deref->deref_type) { |
| case nir_deref_type_array: |
| case nir_deref_type_array_wildcard: { |
| const struct glsl_type *arr_type = nir_deref_instr_parent(deref)->type; |
| unsigned stride = glsl_get_explicit_stride(arr_type); |
| |
| if ((glsl_type_is_matrix(arr_type) && |
| glsl_matrix_type_is_row_major(arr_type)) || |
| (glsl_type_is_vector(arr_type) && stride == 0)) |
| stride = type_scalar_size_bytes(arr_type); |
| |
| return stride; |
| } |
| case nir_deref_type_ptr_as_array: |
| return nir_deref_instr_array_stride(nir_deref_instr_parent(deref)); |
| case nir_deref_type_cast: |
| return deref->cast.ptr_stride; |
| default: |
| return 0; |
| } |
| } |
| |
| static unsigned |
| type_get_array_stride(const struct glsl_type *elem_type, |
| glsl_type_size_align_func size_align) |
| { |
| unsigned elem_size, elem_align; |
| size_align(elem_type, &elem_size, &elem_align); |
| return ALIGN_POT(elem_size, elem_align); |
| } |
| |
| static unsigned |
| struct_type_get_field_offset(const struct glsl_type *struct_type, |
| glsl_type_size_align_func size_align, |
| unsigned field_idx) |
| { |
| assert(glsl_type_is_struct_or_ifc(struct_type)); |
| unsigned offset = 0; |
| for (unsigned i = 0; i <= field_idx; i++) { |
| unsigned elem_size, elem_align; |
| size_align(glsl_get_struct_field(struct_type, i), &elem_size, &elem_align); |
| offset = ALIGN_POT(offset, elem_align); |
| if (i < field_idx) |
| offset += elem_size; |
| } |
| return offset; |
| } |
| |
| unsigned |
| nir_deref_instr_get_const_offset(nir_deref_instr *deref, |
| glsl_type_size_align_func size_align) |
| { |
| nir_deref_path path; |
| nir_deref_path_init(&path, deref, NULL); |
| |
| unsigned offset = 0; |
| for (nir_deref_instr **p = &path.path[1]; *p; p++) { |
| switch ((*p)->deref_type) { |
| case nir_deref_type_array: |
| offset += nir_src_as_uint((*p)->arr.index) * |
| type_get_array_stride((*p)->type, size_align); |
| break; |
| case nir_deref_type_struct: { |
| /* p starts at path[1], so this is safe */ |
| nir_deref_instr *parent = *(p - 1); |
| offset += struct_type_get_field_offset(parent->type, size_align, |
| (*p)->strct.index); |
| break; |
| } |
| case nir_deref_type_cast: |
| /* A cast doesn't contribute to the offset */ |
| break; |
| default: |
| unreachable("Unsupported deref type"); |
| } |
| } |
| |
| nir_deref_path_finish(&path); |
| |
| return offset; |
| } |
| |
| nir_ssa_def * |
| nir_build_deref_offset(nir_builder *b, nir_deref_instr *deref, |
| glsl_type_size_align_func size_align) |
| { |
| nir_deref_path path; |
| nir_deref_path_init(&path, deref, NULL); |
| |
| nir_ssa_def *offset = nir_imm_intN_t(b, 0, deref->dest.ssa.bit_size); |
| for (nir_deref_instr **p = &path.path[1]; *p; p++) { |
| switch ((*p)->deref_type) { |
| case nir_deref_type_array: { |
| nir_ssa_def *index = nir_ssa_for_src(b, (*p)->arr.index, 1); |
| int stride = type_get_array_stride((*p)->type, size_align); |
| offset = nir_iadd(b, offset, nir_amul_imm(b, index, stride)); |
| break; |
| } |
| case nir_deref_type_struct: { |
| /* p starts at path[1], so this is safe */ |
| nir_deref_instr *parent = *(p - 1); |
| unsigned field_offset = |
| struct_type_get_field_offset(parent->type, size_align, |
| (*p)->strct.index); |
| offset = nir_iadd_imm(b, offset, field_offset); |
| break; |
| } |
| case nir_deref_type_cast: |
| /* A cast doesn't contribute to the offset */ |
| break; |
| default: |
| unreachable("Unsupported deref type"); |
| } |
| } |
| |
| nir_deref_path_finish(&path); |
| |
| return offset; |
| } |
| |
| bool |
| nir_remove_dead_derefs_impl(nir_function_impl *impl) |
| { |
| bool progress = false; |
| |
| nir_foreach_block(block, impl) { |
| nir_foreach_instr_safe(instr, block) { |
| if (instr->type == nir_instr_type_deref && |
| nir_deref_instr_remove_if_unused(nir_instr_as_deref(instr))) |
| progress = true; |
| } |
| } |
| |
| if (progress) |
| nir_metadata_preserve(impl, nir_metadata_block_index | |
| nir_metadata_dominance); |
| |
| return progress; |
| } |
| |
| bool |
| nir_remove_dead_derefs(nir_shader *shader) |
| { |
| bool progress = false; |
| nir_foreach_function(function, shader) { |
| if (function->impl && nir_remove_dead_derefs_impl(function->impl)) |
| progress = true; |
| } |
| |
| return progress; |
| } |
| |
| void |
| nir_fixup_deref_modes(nir_shader *shader) |
| { |
| nir_foreach_function(function, shader) { |
| if (!function->impl) |
| continue; |
| |
| nir_foreach_block(block, function->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_cast) |
| continue; |
| |
| nir_variable_mode parent_mode; |
| if (deref->deref_type == nir_deref_type_var) { |
| parent_mode = deref->var->data.mode; |
| } else { |
| assert(deref->parent.is_ssa); |
| nir_deref_instr *parent = |
| nir_instr_as_deref(deref->parent.ssa->parent_instr); |
| parent_mode = parent->mode; |
| } |
| |
| deref->mode = parent_mode; |
| } |
| } |
| } |
| } |
| |
| static bool |
| modes_may_alias(nir_variable_mode a, nir_variable_mode b) |
| { |
| /* Generic pointers can alias with SSBOs */ |
| if ((a == nir_var_mem_ssbo || a == nir_var_mem_global) && |
| (b == nir_var_mem_ssbo || b == nir_var_mem_global)) |
| return true; |
| |
| /* In the general case, pointers can only alias if they have the same mode. |
| * |
| * NOTE: In future, with things like OpenCL generic pointers, this may not |
| * be true and will have to be re-evaluated. However, with graphics only, |
| * it should be safe. |
| */ |
| return a == b; |
| } |
| |
| static bool |
| deref_path_contains_coherent_decoration(nir_deref_path *path) |
| { |
| assert(path->path[0]->deref_type == nir_deref_type_var); |
| |
| if (path->path[0]->var->data.access & ACCESS_COHERENT) |
| return true; |
| |
| for (nir_deref_instr **p = &path->path[1]; *p; p++) { |
| if ((*p)->deref_type != nir_deref_type_struct) |
| continue; |
| |
| const struct glsl_type *struct_type = (*(p - 1))->type; |
| const struct glsl_struct_field *field = |
| glsl_get_struct_field_data(struct_type, (*p)->strct.index); |
| if (field->memory_coherent) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| nir_deref_compare_result |
| nir_compare_deref_paths(nir_deref_path *a_path, |
| nir_deref_path *b_path) |
| { |
| if (!modes_may_alias(b_path->path[0]->mode, a_path->path[0]->mode)) |
| return nir_derefs_do_not_alias; |
| |
| if (a_path->path[0]->deref_type != b_path->path[0]->deref_type) |
| return nir_derefs_may_alias_bit; |
| |
| if (a_path->path[0]->deref_type == nir_deref_type_var) { |
| if (a_path->path[0]->var != b_path->path[0]->var) { |
| /* Shader and function temporaries aren't backed by memory so two |
| * distinct variables never alias. |
| */ |
| static const nir_variable_mode temp_var_modes = |
| nir_var_shader_temp | nir_var_function_temp; |
| if ((a_path->path[0]->mode & temp_var_modes) || |
| (b_path->path[0]->mode & temp_var_modes)) |
| return nir_derefs_do_not_alias; |
| |
| /* If they are both declared coherent or have coherent somewhere in |
| * their path (due to a member of an interface being declared |
| * coherent), we have to assume we that we could have any kind of |
| * aliasing. Otherwise, they could still alias but the client didn't |
| * tell us and that's their fault. |
| */ |
| if (deref_path_contains_coherent_decoration(a_path) && |
| deref_path_contains_coherent_decoration(b_path)) |
| return nir_derefs_may_alias_bit; |
| |
| /* If we can chase the deref all the way back to the variable and |
| * they're not the same variable and at least one is not declared |
| * coherent, we know they can't possibly alias. |
| */ |
| return nir_derefs_do_not_alias; |
| } |
| } else { |
| assert(a_path->path[0]->deref_type == nir_deref_type_cast); |
| /* If they're not exactly the same cast, it's hard to compare them so we |
| * just assume they alias. Comparing casts is tricky as there are lots |
| * of things such as mode, type, etc. to make sure work out; for now, we |
| * just assume nit_opt_deref will combine them and compare the deref |
| * instructions. |
| * |
| * TODO: At some point in the future, we could be clever and understand |
| * that a float[] and int[] have the same layout and aliasing structure |
| * but double[] and vec3[] do not and we could potentially be a bit |
| * smarter here. |
| */ |
| if (a_path->path[0] != b_path->path[0]) |
| return nir_derefs_may_alias_bit; |
| } |
| |
| /* Start off assuming they fully compare. We ignore equality for now. In |
| * the end, we'll determine that by containment. |
| */ |
| nir_deref_compare_result result = nir_derefs_may_alias_bit | |
| nir_derefs_a_contains_b_bit | |
| nir_derefs_b_contains_a_bit; |
| |
| nir_deref_instr **a_p = &a_path->path[1]; |
| nir_deref_instr **b_p = &b_path->path[1]; |
| while (*a_p != NULL && *a_p == *b_p) { |
| a_p++; |
| b_p++; |
| } |
| |
| /* We're at either the tail or the divergence point between the two deref |
| * paths. Look to see if either contains cast or a ptr_as_array deref. If |
| * it does we don't know how to safely make any inferences. Hopefully, |
| * nir_opt_deref will clean most of these up and we can start inferring |
| * things again. |
| * |
| * In theory, we could do a bit better. For instance, we could detect the |
| * case where we have exactly one ptr_as_array deref in the chain after the |
| * divergence point and it's matched in both chains and the two chains have |
| * different constant indices. |
| */ |
| for (nir_deref_instr **t_p = a_p; *t_p; t_p++) { |
| if ((*t_p)->deref_type == nir_deref_type_cast || |
| (*t_p)->deref_type == nir_deref_type_ptr_as_array) |
| return nir_derefs_may_alias_bit; |
| } |
| for (nir_deref_instr **t_p = b_p; *t_p; t_p++) { |
| if ((*t_p)->deref_type == nir_deref_type_cast || |
| (*t_p)->deref_type == nir_deref_type_ptr_as_array) |
| return nir_derefs_may_alias_bit; |
| } |
| |
| while (*a_p != NULL && *b_p != NULL) { |
| nir_deref_instr *a_tail = *(a_p++); |
| nir_deref_instr *b_tail = *(b_p++); |
| |
| switch (a_tail->deref_type) { |
| case nir_deref_type_array: |
| case nir_deref_type_array_wildcard: { |
| assert(b_tail->deref_type == nir_deref_type_array || |
| b_tail->deref_type == nir_deref_type_array_wildcard); |
| |
| if (a_tail->deref_type == nir_deref_type_array_wildcard) { |
| if (b_tail->deref_type != nir_deref_type_array_wildcard) |
| result &= ~nir_derefs_b_contains_a_bit; |
| } else if (b_tail->deref_type == nir_deref_type_array_wildcard) { |
| if (a_tail->deref_type != nir_deref_type_array_wildcard) |
| result &= ~nir_derefs_a_contains_b_bit; |
| } else { |
| assert(a_tail->deref_type == nir_deref_type_array && |
| b_tail->deref_type == nir_deref_type_array); |
| assert(a_tail->arr.index.is_ssa && b_tail->arr.index.is_ssa); |
| |
| if (nir_src_is_const(a_tail->arr.index) && |
| nir_src_is_const(b_tail->arr.index)) { |
| /* If they're both direct and have different offsets, they |
| * don't even alias much less anything else. |
| */ |
| if (nir_src_as_uint(a_tail->arr.index) != |
| nir_src_as_uint(b_tail->arr.index)) |
| return nir_derefs_do_not_alias; |
| } else if (a_tail->arr.index.ssa == b_tail->arr.index.ssa) { |
| /* They're the same indirect, continue on */ |
| } else { |
| /* They're not the same index so we can't prove anything about |
| * containment. |
| */ |
| result &= ~(nir_derefs_a_contains_b_bit | nir_derefs_b_contains_a_bit); |
| } |
| } |
| break; |
| } |
| |
| case nir_deref_type_struct: { |
| /* If they're different struct members, they don't even alias */ |
| if (a_tail->strct.index != b_tail->strct.index) |
| return nir_derefs_do_not_alias; |
| break; |
| } |
| |
| default: |
| unreachable("Invalid deref type"); |
| } |
| } |
| |
| /* If a is longer than b, then it can't contain b */ |
| if (*a_p != NULL) |
| result &= ~nir_derefs_a_contains_b_bit; |
| if (*b_p != NULL) |
| result &= ~nir_derefs_b_contains_a_bit; |
| |
| /* If a contains b and b contains a they must be equal. */ |
| if ((result & nir_derefs_a_contains_b_bit) && (result & nir_derefs_b_contains_a_bit)) |
| result |= nir_derefs_equal_bit; |
| |
| return result; |
| } |
| |
| nir_deref_compare_result |
| nir_compare_derefs(nir_deref_instr *a, nir_deref_instr *b) |
| { |
| if (a == b) { |
| return nir_derefs_equal_bit | nir_derefs_may_alias_bit | |
| nir_derefs_a_contains_b_bit | nir_derefs_b_contains_a_bit; |
| } |
| |
| nir_deref_path a_path, b_path; |
| nir_deref_path_init(&a_path, a, NULL); |
| nir_deref_path_init(&b_path, b, NULL); |
| assert(a_path.path[0]->deref_type == nir_deref_type_var || |
| a_path.path[0]->deref_type == nir_deref_type_cast); |
| assert(b_path.path[0]->deref_type == nir_deref_type_var || |
| b_path.path[0]->deref_type == nir_deref_type_cast); |
| |
| nir_deref_compare_result result = nir_compare_deref_paths(&a_path, &b_path); |
| |
| nir_deref_path_finish(&a_path); |
| nir_deref_path_finish(&b_path); |
| |
| return result; |
| } |
| |
| struct rematerialize_deref_state { |
| bool progress; |
| nir_builder builder; |
| nir_block *block; |
| struct hash_table *cache; |
| }; |
| |
| static nir_deref_instr * |
| rematerialize_deref_in_block(nir_deref_instr *deref, |
| struct rematerialize_deref_state *state) |
| { |
| if (deref->instr.block == state->block) |
| return deref; |
| |
| if (!state->cache) { |
| state->cache = _mesa_pointer_hash_table_create(NULL); |
| } |
| |
| struct hash_entry *cached = _mesa_hash_table_search(state->cache, deref); |
| if (cached) |
| return cached->data; |
| |
| nir_builder *b = &state->builder; |
| nir_deref_instr *new_deref = |
| nir_deref_instr_create(b->shader, deref->deref_type); |
| new_deref->mode = deref->mode; |
| new_deref->type = deref->type; |
| |
| if (deref->deref_type == nir_deref_type_var) { |
| new_deref->var = deref->var; |
| } else { |
| nir_deref_instr *parent = nir_src_as_deref(deref->parent); |
| if (parent) { |
| parent = rematerialize_deref_in_block(parent, state); |
| new_deref->parent = nir_src_for_ssa(&parent->dest.ssa); |
| } else { |
| nir_src_copy(&new_deref->parent, &deref->parent, new_deref); |
| } |
| } |
| |
| switch (deref->deref_type) { |
| case nir_deref_type_var: |
| case nir_deref_type_array_wildcard: |
| /* Nothing more to do */ |
| break; |
| |
| case nir_deref_type_cast: |
| new_deref->cast.ptr_stride = deref->cast.ptr_stride; |
| break; |
| |
| case nir_deref_type_array: |
| case nir_deref_type_ptr_as_array: |
| assert(!nir_src_as_deref(deref->arr.index)); |
| nir_src_copy(&new_deref->arr.index, &deref->arr.index, new_deref); |
| break; |
| |
| case nir_deref_type_struct: |
| new_deref->strct.index = deref->strct.index; |
| break; |
| |
| default: |
| unreachable("Invalid deref instruction type"); |
| } |
| |
| nir_ssa_dest_init(&new_deref->instr, &new_deref->dest, |
| deref->dest.ssa.num_components, |
| deref->dest.ssa.bit_size, |
| deref->dest.ssa.name); |
| nir_builder_instr_insert(b, &new_deref->instr); |
| |
| return new_deref; |
| } |
| |
| static bool |
| rematerialize_deref_src(nir_src *src, void *_state) |
| { |
| struct rematerialize_deref_state *state = _state; |
| |
| nir_deref_instr *deref = nir_src_as_deref(*src); |
| if (!deref) |
| return true; |
| |
| nir_deref_instr *block_deref = rematerialize_deref_in_block(deref, state); |
| if (block_deref != deref) { |
| nir_instr_rewrite_src(src->parent_instr, src, |
| nir_src_for_ssa(&block_deref->dest.ssa)); |
| nir_deref_instr_remove_if_unused(deref); |
| state->progress = true; |
| } |
| |
| return true; |
| } |
| |
| /** Re-materialize derefs in every block |
| * |
| * This pass re-materializes deref instructions in every block in which it is |
| * used. After this pass has been run, every use of a deref will be of a |
| * deref in the same block as the use. Also, all unused derefs will be |
| * deleted as a side-effect. |
| * |
| * Derefs used as sources of phi instructions are not rematerialized. |
| */ |
| bool |
| nir_rematerialize_derefs_in_use_blocks_impl(nir_function_impl *impl) |
| { |
| struct rematerialize_deref_state state = { 0 }; |
| nir_builder_init(&state.builder, impl); |
| |
| nir_foreach_block_unstructured(block, impl) { |
| state.block = block; |
| |
| /* Start each block with a fresh cache */ |
| if (state.cache) |
| _mesa_hash_table_clear(state.cache, NULL); |
| |
| nir_foreach_instr_safe(instr, block) { |
| if (instr->type == nir_instr_type_deref && |
| nir_deref_instr_remove_if_unused(nir_instr_as_deref(instr))) |
| continue; |
| |
| /* If a deref is used in a phi, we can't rematerialize it, as the new |
| * derefs would appear before the phi, which is not valid. |
| */ |
| if (instr->type == nir_instr_type_phi) |
| continue; |
| |
| state.builder.cursor = nir_before_instr(instr); |
| nir_foreach_src(instr, rematerialize_deref_src, &state); |
| } |
| |
| #ifndef NDEBUG |
| nir_if *following_if = nir_block_get_following_if(block); |
| if (following_if) |
| assert(!nir_src_as_deref(following_if->condition)); |
| #endif |
| } |
| |
| _mesa_hash_table_destroy(state.cache, NULL); |
| |
| return state.progress; |
| } |
| |
| static void |
| nir_deref_instr_fixup_child_types(nir_deref_instr *parent) |
| { |
| nir_foreach_use(use, &parent->dest.ssa) { |
| if (use->parent_instr->type != nir_instr_type_deref) |
| continue; |
| |
| nir_deref_instr *child = nir_instr_as_deref(use->parent_instr); |
| switch (child->deref_type) { |
| case nir_deref_type_var: |
| unreachable("nir_deref_type_var cannot be a child"); |
| |
| case nir_deref_type_array: |
| case nir_deref_type_array_wildcard: |
| child->type = glsl_get_array_element(parent->type); |
| break; |
| |
| case nir_deref_type_ptr_as_array: |
| child->type = parent->type; |
| break; |
| |
| case nir_deref_type_struct: |
| child->type = glsl_get_struct_field(parent->type, |
| child->strct.index); |
| break; |
| |
| case nir_deref_type_cast: |
| /* We stop the recursion here */ |
| continue; |
| } |
| |
| /* Recurse into children */ |
| nir_deref_instr_fixup_child_types(child); |
| } |
| } |
| |
| static bool |
| is_trivial_array_deref_cast(nir_deref_instr *cast) |
| { |
| assert(is_trivial_deref_cast(cast)); |
| |
| nir_deref_instr *parent = nir_src_as_deref(cast->parent); |
| |
| if (parent->deref_type == nir_deref_type_array) { |
| return cast->cast.ptr_stride == |
| glsl_get_explicit_stride(nir_deref_instr_parent(parent)->type); |
| } else if (parent->deref_type == nir_deref_type_ptr_as_array) { |
| return cast->cast.ptr_stride == |
| nir_deref_instr_array_stride(parent); |
| } else { |
| return false; |
| } |
| } |
| |
| static bool |
| is_deref_ptr_as_array(nir_instr *instr) |
| { |
| return instr->type == nir_instr_type_deref && |
| nir_instr_as_deref(instr)->deref_type == nir_deref_type_ptr_as_array; |
| } |
| |
| /** |
| * Remove casts that just wrap other casts. |
| */ |
| static bool |
| opt_remove_cast_cast(nir_deref_instr *cast) |
| { |
| nir_deref_instr *first_cast = cast; |
| |
| while (true) { |
| nir_deref_instr *parent = nir_deref_instr_parent(first_cast); |
| if (parent == NULL || parent->deref_type != nir_deref_type_cast) |
| break; |
| first_cast = parent; |
| } |
| if (cast == first_cast) |
| return false; |
| |
| nir_instr_rewrite_src(&cast->instr, &cast->parent, |
| nir_src_for_ssa(first_cast->parent.ssa)); |
| return true; |
| } |
| |
| static bool |
| opt_remove_sampler_cast(nir_deref_instr *cast) |
| { |
| assert(cast->deref_type == nir_deref_type_cast); |
| nir_deref_instr *parent = nir_src_as_deref(cast->parent); |
| if (parent == NULL) |
| return false; |
| |
| /* Strip both types down to their non-array type and bail if there are any |
| * discrepancies in array lengths. |
| */ |
| const struct glsl_type *parent_type = parent->type; |
| const struct glsl_type *cast_type = cast->type; |
| while (glsl_type_is_array(parent_type) && glsl_type_is_array(cast_type)) { |
| if (glsl_get_length(parent_type) != glsl_get_length(cast_type)) |
| return false; |
| parent_type = glsl_get_array_element(parent_type); |
| cast_type = glsl_get_array_element(cast_type); |
| } |
| |
| if (glsl_type_is_array(parent_type) || glsl_type_is_array(cast_type)) |
| return false; |
| |
| if (!glsl_type_is_sampler(parent_type) || |
| cast_type != glsl_bare_sampler_type()) |
| return false; |
| |
| /* We're a cast from a more detailed sampler type to a bare sampler */ |
| nir_ssa_def_rewrite_uses(&cast->dest.ssa, |
| nir_src_for_ssa(&parent->dest.ssa)); |
| nir_instr_remove(&cast->instr); |
| |
| /* Recursively crawl the deref tree and clean up types */ |
| nir_deref_instr_fixup_child_types(parent); |
| |
| 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_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 (cast->cast.align_mul > 0) |
| 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; |
| |
| if (opt_remove_sampler_cast(cast)) |
| return true; |
| |
| progress = opt_remove_cast_cast(cast); |
| if (!is_trivial_deref_cast(cast)) |
| return progress; |
| |
| /* If this deref still contains useful alignment information, we don't want |
| * to delete it. |
| */ |
| if (cast->cast.align_mul > 0) |
| return progress; |
| |
| bool trivial_array_cast = is_trivial_array_deref_cast(cast); |
| |
| assert(cast->dest.is_ssa); |
| assert(cast->parent.is_ssa); |
| |
| nir_foreach_use_safe(use_src, &cast->dest.ssa) { |
| /* If this isn't a trivial array cast, we can't propagate into |
| * ptr_as_array derefs. |
| */ |
| if (is_deref_ptr_as_array(use_src->parent_instr) && |
| !trivial_array_cast) |
| continue; |
| |
| nir_instr_rewrite_src(use_src->parent_instr, use_src, cast->parent); |
| progress = true; |
| } |
| |
| /* If uses would be a bit crazy */ |
| assert(list_is_empty(&cast->dest.ssa.if_uses)); |
| |
| if (nir_deref_instr_remove_if_unused(cast)) |
| progress = true; |
| |
| return progress; |
| } |
| |
| static bool |
| opt_deref_ptr_as_array(nir_builder *b, nir_deref_instr *deref) |
| { |
| assert(deref->deref_type == nir_deref_type_ptr_as_array); |
| |
| nir_deref_instr *parent = nir_deref_instr_parent(deref); |
| |
| if (nir_src_is_const(deref->arr.index) && |
| nir_src_as_int(deref->arr.index) == 0) { |
| /* If it's a ptr_as_array deref with an index of 0, it does nothing |
| * and we can just replace its uses with its parent. |
| * |
| * The source of a ptr_as_array deref always has a deref_type of |
| * nir_deref_type_array or nir_deref_type_cast. If it's a cast, it |
| * may be trivial and we may be able to get rid of that too. Any |
| * trivial cast of trivial cast cases should be handled already by |
| * opt_deref_cast() above. |
| */ |
| if (parent->deref_type == nir_deref_type_cast && |
| is_trivial_deref_cast(parent)) |
| parent = nir_deref_instr_parent(parent); |
| nir_ssa_def_rewrite_uses(&deref->dest.ssa, |
| nir_src_for_ssa(&parent->dest.ssa)); |
| nir_instr_remove(&deref->instr); |
| return true; |
| } |
| |
| if (parent->deref_type != nir_deref_type_array && |
| parent->deref_type != nir_deref_type_ptr_as_array) |
| return false; |
| |
| assert(parent->parent.is_ssa); |
| assert(parent->arr.index.is_ssa); |
| assert(deref->arr.index.is_ssa); |
| |
| nir_ssa_def *new_idx = nir_iadd(b, parent->arr.index.ssa, |
| deref->arr.index.ssa); |
| |
| deref->deref_type = parent->deref_type; |
| nir_instr_rewrite_src(&deref->instr, &deref->parent, parent->parent); |
| nir_instr_rewrite_src(&deref->instr, &deref->arr.index, |
| nir_src_for_ssa(new_idx)); |
| return true; |
| } |
| |
| bool |
| nir_opt_deref_impl(nir_function_impl *impl) |
| { |
| bool progress = false; |
| |
| nir_builder b; |
| nir_builder_init(&b, impl); |
| |
| nir_foreach_block(block, impl) { |
| nir_foreach_instr_safe(instr, block) { |
| if (instr->type != nir_instr_type_deref) |
| continue; |
| |
| b.cursor = nir_before_instr(instr); |
| |
| nir_deref_instr *deref = nir_instr_as_deref(instr); |
| switch (deref->deref_type) { |
| case nir_deref_type_ptr_as_array: |
| if (opt_deref_ptr_as_array(&b, deref)) |
| progress = true; |
| break; |
| |
| case nir_deref_type_cast: |
| if (opt_deref_cast(&b, deref)) |
| progress = true; |
| break; |
| |
| default: |
| /* Do nothing */ |
| break; |
| } |
| } |
| } |
| |
| 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_deref(nir_shader *shader) |
| { |
| bool progress = false; |
| |
| nir_foreach_function(func, shader) { |
| if (func->impl && nir_opt_deref_impl(func->impl)) |
| progress = true; |
| } |
| |
| return progress; |
| } |
