/* * Copyright © 2015 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 "vtn_private.h" #include "spirv_info.h" #include "nir/nir_vla.h" #include "util/u_debug.h" static unsigned glsl_type_count_function_params(const struct glsl_type *type) { if (glsl_type_is_vector_or_scalar(type)) { return 1; } else if (glsl_type_is_array_or_matrix(type)) { return glsl_get_length(type) * glsl_type_count_function_params(glsl_get_array_element(type)); } else { assert(glsl_type_is_struct_or_ifc(type)); unsigned count = 0; unsigned elems = glsl_get_length(type); for (unsigned i = 0; i < elems; i++) { const struct glsl_type *elem_type = glsl_get_struct_field(type, i); count += glsl_type_count_function_params(elem_type); } return count; } } static void glsl_type_add_to_function_params(const struct glsl_type *type, nir_function *func, unsigned *param_idx) { if (glsl_type_is_vector_or_scalar(type)) { func->params[(*param_idx)++] = (nir_parameter) { .num_components = glsl_get_vector_elements(type), .bit_size = glsl_get_bit_size(type), }; } else if (glsl_type_is_array_or_matrix(type)) { unsigned elems = glsl_get_length(type); const struct glsl_type *elem_type = glsl_get_array_element(type); for (unsigned i = 0; i < elems; i++) glsl_type_add_to_function_params(elem_type,func, param_idx); } else { assert(glsl_type_is_struct_or_ifc(type)); unsigned elems = glsl_get_length(type); for (unsigned i = 0; i < elems; i++) { const struct glsl_type *elem_type = glsl_get_struct_field(type, i); glsl_type_add_to_function_params(elem_type, func, param_idx); } } } static void vtn_ssa_value_add_to_call_params(struct vtn_builder *b, struct vtn_ssa_value *value, nir_call_instr *call, unsigned *param_idx) { if (glsl_type_is_vector_or_scalar(value->type)) { call->params[(*param_idx)++] = nir_src_for_ssa(value->def); } else { unsigned elems = glsl_get_length(value->type); for (unsigned i = 0; i < elems; i++) { vtn_ssa_value_add_to_call_params(b, value->elems[i], call, param_idx); } } } static void vtn_ssa_value_load_function_param(struct vtn_builder *b, struct vtn_ssa_value *value, unsigned *param_idx) { if (glsl_type_is_vector_or_scalar(value->type)) { value->def = nir_load_param(&b->nb, (*param_idx)++); } else { unsigned elems = glsl_get_length(value->type); for (unsigned i = 0; i < elems; i++) vtn_ssa_value_load_function_param(b, value->elems[i], param_idx); } } void vtn_handle_function_call(struct vtn_builder *b, SpvOp opcode, const uint32_t *w, unsigned count) { struct vtn_function *vtn_callee = vtn_value(b, w[3], vtn_value_type_function)->func; vtn_callee->referenced = true; nir_call_instr *call = nir_call_instr_create(b->nb.shader, vtn_callee->nir_func); unsigned param_idx = 0; nir_deref_instr *ret_deref = NULL; struct vtn_type *ret_type = vtn_callee->type->return_type; if (ret_type->base_type != vtn_base_type_void) { nir_variable *ret_tmp = nir_local_variable_create(b->nb.impl, glsl_get_bare_type(ret_type->type), "return_tmp"); ret_deref = nir_build_deref_var(&b->nb, ret_tmp); call->params[param_idx++] = nir_src_for_ssa(&ret_deref->def); } for (unsigned i = 0; i < vtn_callee->type->length; i++) { vtn_ssa_value_add_to_call_params(b, vtn_ssa_value(b, w[4 + i]), call, ¶m_idx); } assert(param_idx == call->num_params); nir_builder_instr_insert(&b->nb, &call->instr); if (ret_type->base_type == vtn_base_type_void) { vtn_push_value(b, w[2], vtn_value_type_undef); } else { vtn_push_ssa_value(b, w[2], vtn_local_load(b, ret_deref, 0)); } } static void function_decoration_cb(struct vtn_builder *b, struct vtn_value *val, int member, const struct vtn_decoration *dec, void *void_func) { struct vtn_function *func = void_func; switch (dec->decoration) { case SpvDecorationLinkageAttributes: { unsigned name_words; const char *name = vtn_string_literal(b, dec->operands, dec->num_operands, &name_words); vtn_fail_if(name_words >= dec->num_operands, "Malformed LinkageAttributes decoration"); (void)name; /* TODO: What is this? */ func->linkage = dec->operands[name_words]; break; } default: break; } } bool vtn_cfg_handle_prepass_instruction(struct vtn_builder *b, SpvOp opcode, const uint32_t *w, unsigned count) { switch (opcode) { case SpvOpFunction: { vtn_assert(b->func == NULL); b->func = vtn_zalloc(b, struct vtn_function); list_inithead(&b->func->body); b->func->linkage = SpvLinkageTypeMax; b->func->control = w[3]; list_inithead(&b->func->constructs); UNUSED const struct glsl_type *result_type = vtn_get_type(b, w[1])->type; struct vtn_value *val = vtn_push_value(b, w[2], vtn_value_type_function); val->func = b->func; vtn_foreach_decoration(b, val, function_decoration_cb, b->func); b->func->type = vtn_get_type(b, w[4]); const struct vtn_type *func_type = b->func->type; vtn_assert(func_type->return_type->type == result_type); nir_function *func = nir_function_create(b->shader, ralloc_strdup(b->shader, val->name)); unsigned num_params = 0; for (unsigned i = 0; i < func_type->length; i++) num_params += glsl_type_count_function_params(func_type->params[i]->type); /* Add one parameter for the function return value */ if (func_type->return_type->base_type != vtn_base_type_void) num_params++; func->should_inline = b->func->control & SpvFunctionControlInlineMask; func->dont_inline = b->func->control & SpvFunctionControlDontInlineMask; func->is_exported = b->func->linkage == SpvLinkageTypeExport; func->num_params = num_params; func->params = ralloc_array(b->shader, nir_parameter, num_params); unsigned idx = 0; if (func_type->return_type->base_type != vtn_base_type_void) { nir_address_format addr_format = vtn_mode_to_address_format(b, vtn_variable_mode_function); /* The return value is a regular pointer */ func->params[idx++] = (nir_parameter) { .num_components = nir_address_format_num_components(addr_format), .bit_size = nir_address_format_bit_size(addr_format), }; } for (unsigned i = 0; i < func_type->length; i++) glsl_type_add_to_function_params(func_type->params[i]->type, func, &idx); assert(idx == num_params); b->func->nir_func = func; /* Set up a nir_function_impl and the builder so we can load arguments * directly in our OpFunctionParameter handler. */ nir_function_impl *impl = nir_function_impl_create(func); b->nb = nir_builder_at(nir_before_impl(impl)); b->nb.exact = b->exact; b->func_param_idx = 0; /* The return value is the first parameter */ if (func_type->return_type->base_type != vtn_base_type_void) b->func_param_idx++; break; } case SpvOpFunctionEnd: b->func->end = w; if (b->func->start_block == NULL) { vtn_fail_if(b->func->linkage != SpvLinkageTypeImport, "A function declaration (an OpFunction with no basic " "blocks), must have a Linkage Attributes Decoration " "with the Import Linkage Type."); /* In this case, the function didn't have any actual blocks. It's * just a prototype so delete the function_impl. */ b->func->nir_func->impl = NULL; } else { vtn_fail_if(b->func->linkage == SpvLinkageTypeImport, "A function definition (an OpFunction with basic blocks) " "cannot be decorated with the Import Linkage Type."); } b->func = NULL; break; case SpvOpFunctionParameter: { vtn_assert(b->func_param_idx < b->func->nir_func->num_params); struct vtn_type *type = vtn_get_type(b, w[1]); struct vtn_ssa_value *value = vtn_create_ssa_value(b, type->type); vtn_ssa_value_load_function_param(b, value, &b->func_param_idx); vtn_push_ssa_value(b, w[2], value); break; } case SpvOpLabel: { vtn_assert(b->block == NULL); b->block = vtn_zalloc(b, struct vtn_block); b->block->label = w; vtn_push_value(b, w[1], vtn_value_type_block)->block = b->block; b->func->block_count++; if (b->func->start_block == NULL) { /* This is the first block encountered for this function. In this * case, we set the start block and add it to the list of * implemented functions that we'll walk later. */ b->func->start_block = b->block; list_addtail(&b->func->link, &b->functions); } break; } case SpvOpSelectionMerge: case SpvOpLoopMerge: vtn_assert(b->block && b->block->merge == NULL); b->block->merge = w; break; case SpvOpBranch: case SpvOpBranchConditional: case SpvOpSwitch: case SpvOpKill: case SpvOpTerminateInvocation: case SpvOpIgnoreIntersectionKHR: case SpvOpTerminateRayKHR: case SpvOpEmitMeshTasksEXT: case SpvOpReturn: case SpvOpReturnValue: case SpvOpUnreachable: if (b->wa_ignore_return_after_emit_mesh_tasks && opcode == SpvOpReturn && !b->block) { /* At this point block was already reset by * SpvOpEmitMeshTasksEXT. */ break; } vtn_assert(b->block && b->block->branch == NULL); b->block->branch = w; b->block = NULL; break; default: /* Continue on as per normal */ return true; } return true; } /* returns the default block */ void vtn_parse_switch(struct vtn_builder *b, const uint32_t *branch, struct list_head *case_list) { const uint32_t *branch_end = branch + (branch[0] >> SpvWordCountShift); struct vtn_value *sel_val = vtn_untyped_value(b, branch[1]); vtn_fail_if(!sel_val->type || sel_val->type->base_type != vtn_base_type_scalar, "Selector of OpSwitch must have a type of OpTypeInt"); nir_alu_type sel_type = nir_get_nir_type_for_glsl_type(sel_val->type->type); vtn_fail_if(nir_alu_type_get_base_type(sel_type) != nir_type_int && nir_alu_type_get_base_type(sel_type) != nir_type_uint, "Selector of OpSwitch must have a type of OpTypeInt"); struct hash_table *block_to_case = _mesa_pointer_hash_table_create(b); bool is_default = true; const unsigned bitsize = nir_alu_type_get_type_size(sel_type); for (const uint32_t *w = branch + 2; w < branch_end;) { uint64_t literal = 0; if (!is_default) { if (bitsize <= 32) { literal = *(w++); } else { assert(bitsize == 64); literal = vtn_u64_literal(w); w += 2; } } struct vtn_block *case_block = vtn_block(b, *(w++)); struct hash_entry *case_entry = _mesa_hash_table_search(block_to_case, case_block); struct vtn_case *cse; if (case_entry) { cse = case_entry->data; } else { cse = vtn_zalloc(b, struct vtn_case); cse->block = case_block; cse->block->switch_case = cse; util_dynarray_init(&cse->values, b); list_addtail(&cse->link, case_list); _mesa_hash_table_insert(block_to_case, case_block, cse); } if (is_default) { cse->is_default = true; } else { util_dynarray_append(&cse->values, uint64_t, literal); } is_default = false; } _mesa_hash_table_destroy(block_to_case, NULL); } void vtn_build_cfg(struct vtn_builder *b, const uint32_t *words, const uint32_t *end) { vtn_foreach_instruction(b, words, end, vtn_cfg_handle_prepass_instruction); if (b->shader->info.stage == MESA_SHADER_KERNEL) return; vtn_build_structured_cfg(b, words, end); } bool vtn_handle_phis_first_pass(struct vtn_builder *b, SpvOp opcode, const uint32_t *w, unsigned count) { if (opcode == SpvOpLabel) return true; /* Nothing to do */ /* If this isn't a phi node, stop. */ if (opcode != SpvOpPhi) return false; /* For handling phi nodes, we do a poor-man's out-of-ssa on the spot. * For each phi, we create a variable with the appropreate type and * do a load from that variable. Then, in a second pass, we add * stores to that variable to each of the predecessor blocks. * * We could do something more intelligent here. However, in order to * handle loops and things properly, we really need dominance * information. It would end up basically being the into-SSA * algorithm all over again. It's easier if we just let * lower_vars_to_ssa do that for us instead of repeating it here. */ struct vtn_type *type = vtn_get_type(b, w[1]); nir_variable *phi_var = nir_local_variable_create(b->nb.impl, type->type, "phi"); struct vtn_value *phi_val = vtn_untyped_value(b, w[2]); if (vtn_value_is_relaxed_precision(b, phi_val)) phi_var->data.precision = GLSL_PRECISION_MEDIUM; _mesa_hash_table_insert(b->phi_table, w, phi_var); vtn_push_ssa_value(b, w[2], vtn_local_load(b, nir_build_deref_var(&b->nb, phi_var), 0)); return true; } static bool vtn_handle_phi_second_pass(struct vtn_builder *b, SpvOp opcode, const uint32_t *w, unsigned count) { if (opcode != SpvOpPhi) return true; struct hash_entry *phi_entry = _mesa_hash_table_search(b->phi_table, w); /* It's possible that this phi is in an unreachable block in which case it * may never have been emitted and therefore may not be in the hash table. * In this case, there's no var for it and it's safe to just bail. */ if (phi_entry == NULL) return true; nir_variable *phi_var = phi_entry->data; for (unsigned i = 3; i < count; i += 2) { struct vtn_block *pred = vtn_block(b, w[i + 1]); /* If block does not have end_nop, that is because it is an unreacheable * block, and hence it is not worth to handle it */ if (!pred->end_nop) continue; b->nb.cursor = nir_after_instr(&pred->end_nop->instr); struct vtn_ssa_value *src = vtn_ssa_value(b, w[i]); vtn_local_store(b, src, nir_build_deref_var(&b->nb, phi_var), 0); } return true; } void vtn_emit_ret_store(struct vtn_builder *b, const struct vtn_block *block) { if ((*block->branch & SpvOpCodeMask) != SpvOpReturnValue) return; vtn_fail_if(b->func->type->return_type->base_type == vtn_base_type_void, "Return with a value from a function returning void"); struct vtn_ssa_value *src = vtn_ssa_value(b, block->branch[1]); const struct glsl_type *ret_type = glsl_get_bare_type(b->func->type->return_type->type); nir_deref_instr *ret_deref = nir_build_deref_cast(&b->nb, nir_load_param(&b->nb, 0), nir_var_function_temp, ret_type, 0); vtn_local_store(b, src, ret_deref, 0); } static struct nir_block * vtn_new_unstructured_block(struct vtn_builder *b, struct vtn_function *func) { struct nir_block *n = nir_block_create(b->shader); exec_list_push_tail(&func->nir_func->impl->body, &n->cf_node.node); n->cf_node.parent = &func->nir_func->impl->cf_node; return n; } static void vtn_add_unstructured_block(struct vtn_builder *b, struct vtn_function *func, struct list_head *work_list, struct vtn_block *block) { if (!block->block) { block->block = vtn_new_unstructured_block(b, func); list_addtail(&block->link, work_list); } } static void vtn_emit_cf_func_unstructured(struct vtn_builder *b, struct vtn_function *func, vtn_instruction_handler handler) { struct list_head work_list; list_inithead(&work_list); func->start_block->block = nir_start_block(func->nir_func->impl); list_addtail(&func->start_block->link, &work_list); while (!list_is_empty(&work_list)) { struct vtn_block *block = list_first_entry(&work_list, struct vtn_block, link); list_del(&block->link); vtn_assert(block->block); const uint32_t *block_start = block->label; const uint32_t *block_end = block->branch; b->nb.cursor = nir_after_block(block->block); block_start = vtn_foreach_instruction(b, block_start, block_end, vtn_handle_phis_first_pass); vtn_foreach_instruction(b, block_start, block_end, handler); block->end_nop = nir_nop(&b->nb); SpvOp op = *block_end & SpvOpCodeMask; switch (op) { case SpvOpBranch: { struct vtn_block *branch_block = vtn_block(b, block->branch[1]); vtn_add_unstructured_block(b, func, &work_list, branch_block); nir_goto(&b->nb, branch_block->block); break; } case SpvOpBranchConditional: { nir_def *cond = vtn_ssa_value(b, block->branch[1])->def; struct vtn_block *then_block = vtn_block(b, block->branch[2]); struct vtn_block *else_block = vtn_block(b, block->branch[3]); vtn_add_unstructured_block(b, func, &work_list, then_block); if (then_block == else_block) { nir_goto(&b->nb, then_block->block); } else { vtn_add_unstructured_block(b, func, &work_list, else_block); nir_goto_if(&b->nb, then_block->block, cond, else_block->block); } break; } case SpvOpSwitch: { struct list_head cases; list_inithead(&cases); vtn_parse_switch(b, block->branch, &cases); nir_def *sel = vtn_get_nir_ssa(b, block->branch[1]); struct vtn_case *def = NULL; vtn_foreach_case(cse, &cases) { if (cse->is_default) { assert(def == NULL); def = cse; continue; } nir_def *cond = nir_imm_false(&b->nb); util_dynarray_foreach(&cse->values, uint64_t, val) cond = nir_ior(&b->nb, cond, nir_ieq_imm(&b->nb, sel, *val)); /* block for the next check */ nir_block *e = vtn_new_unstructured_block(b, func); vtn_add_unstructured_block(b, func, &work_list, cse->block); /* add branching */ nir_goto_if(&b->nb, cse->block->block, cond, e); b->nb.cursor = nir_after_block(e); } vtn_assert(def != NULL); vtn_add_unstructured_block(b, func, &work_list, def->block); /* now that all cases are handled, branch into the default block */ nir_goto(&b->nb, def->block->block); break; } case SpvOpKill: { nir_discard(&b->nb); nir_goto(&b->nb, b->func->nir_func->impl->end_block); break; } case SpvOpUnreachable: case SpvOpReturn: case SpvOpReturnValue: { vtn_emit_ret_store(b, block); nir_goto(&b->nb, b->func->nir_func->impl->end_block); break; } default: vtn_fail("Unhandled opcode %s", spirv_op_to_string(op)); } } } void vtn_function_emit(struct vtn_builder *b, struct vtn_function *func, vtn_instruction_handler instruction_handler) { static int force_unstructured = -1; if (force_unstructured < 0) { force_unstructured = debug_get_bool_option("MESA_SPIRV_FORCE_UNSTRUCTURED", false); } nir_function_impl *impl = func->nir_func->impl; b->nb = nir_builder_at(nir_after_impl(impl)); b->func = func; b->nb.exact = b->exact; b->phi_table = _mesa_pointer_hash_table_create(b); if (b->shader->info.stage == MESA_SHADER_KERNEL || force_unstructured) { impl->structured = false; vtn_emit_cf_func_unstructured(b, func, instruction_handler); } else { vtn_emit_cf_func_structured(b, func, instruction_handler); } vtn_foreach_instruction(b, func->start_block->label, func->end, vtn_handle_phi_second_pass); if (func->nir_func->impl->structured) nir_copy_prop_impl(impl); nir_rematerialize_derefs_in_use_blocks_impl(impl); /* * There are some cases where we need to repair SSA to insert * the needed phi nodes: * * - Early termination instructions `OpKill` and `OpTerminateInvocation`, * in NIR. They're represented by regular intrinsics with no control-flow * semantics. This means that the SSA form from the SPIR-V may not * 100% match NIR. * * - Switches with only default case may also define SSA which may * subsequently be used out of the switch. */ if (func->nir_func->impl->structured) nir_repair_ssa_impl(impl); func->emitted = true; }