| /* |
| * Copyright © 2019 Valve Corporation |
| * |
| * SPDX-License-Identifier: MIT |
| */ |
| |
| #include "aco_builder.h" |
| #include "aco_ir.h" |
| |
| #include <vector> |
| |
| namespace aco { |
| |
| namespace { |
| |
| enum WQMState : uint8_t { |
| Unspecified = 0, |
| Exact, |
| WQM, /* with control flow applied */ |
| }; |
| |
| enum mask_type : uint8_t { |
| mask_type_global = 1 << 0, |
| mask_type_exact = 1 << 1, |
| mask_type_wqm = 1 << 2, |
| mask_type_loop = 1 << 3, /* active lanes of a loop */ |
| }; |
| |
| struct loop_info { |
| Block* loop_header; |
| uint16_t num_exec_masks; |
| bool has_divergent_break; |
| bool has_divergent_continue; |
| bool has_discard; /* has a discard or demote */ |
| loop_info(Block* b, uint16_t num, bool breaks, bool cont, bool discard) |
| : loop_header(b), num_exec_masks(num), has_divergent_break(breaks), |
| has_divergent_continue(cont), has_discard(discard) |
| {} |
| }; |
| |
| struct exec_info { |
| Operand op; /* Either a temporary, exec or const -1. */ |
| uint8_t type; /* enum mask_type */ |
| exec_info() = default; |
| exec_info(const Operand& op_, const uint8_t& type_) : op(op_), type(type_) {} |
| }; |
| |
| struct block_info { |
| std::vector<exec_info> exec; |
| }; |
| |
| struct exec_ctx { |
| Program* program; |
| std::vector<block_info> info; |
| std::vector<loop_info> loop; |
| bool handle_wqm = false; |
| exec_ctx(Program* program_) : program(program_), info(program->blocks.size()) {} |
| }; |
| |
| bool |
| needs_exact(aco_ptr<Instruction>& instr) |
| { |
| if (instr->isMUBUF()) { |
| return instr->mubuf().disable_wqm; |
| } else if (instr->isMTBUF()) { |
| return instr->mtbuf().disable_wqm; |
| } else if (instr->isMIMG()) { |
| return instr->mimg().disable_wqm; |
| } else if (instr->isFlatLike()) { |
| return instr->flatlike().disable_wqm; |
| } else { |
| /* Require Exact for p_jump_to_epilog because if p_exit_early_if_not is |
| * emitted inside the same block, the main FS will always jump to the PS |
| * epilog without considering the exec mask. |
| */ |
| return instr->isEXP() || instr->opcode == aco_opcode::p_jump_to_epilog || |
| instr->opcode == aco_opcode::p_dual_src_export_gfx11; |
| } |
| } |
| |
| WQMState |
| get_instr_needs(aco_ptr<Instruction>& instr) |
| { |
| if (needs_exact(instr)) |
| return Exact; |
| |
| bool pred_by_exec = needs_exec_mask(instr.get()) || instr->opcode == aco_opcode::p_logical_end || |
| instr->isBranch(); |
| |
| return pred_by_exec ? WQM : Unspecified; |
| } |
| |
| void |
| transition_to_WQM(exec_ctx& ctx, Builder bld, unsigned idx) |
| { |
| if (ctx.info[idx].exec.back().type & mask_type_wqm) |
| return; |
| if (ctx.info[idx].exec.back().type & mask_type_global) { |
| Operand exec_mask = ctx.info[idx].exec.back().op; |
| if (exec_mask == Operand(exec, bld.lm)) |
| ctx.info[idx].exec.back().op = bld.copy(bld.def(bld.lm), exec_mask); |
| |
| bld.sop1(Builder::s_wqm, Definition(exec, bld.lm), bld.def(s1, scc), exec_mask); |
| ctx.info[idx].exec.emplace_back(Operand(exec, bld.lm), mask_type_global | mask_type_wqm); |
| return; |
| } |
| /* otherwise, the WQM mask should be one below the current mask */ |
| ctx.info[idx].exec.pop_back(); |
| assert(ctx.info[idx].exec.back().type & mask_type_wqm); |
| assert(ctx.info[idx].exec.back().op.size() == bld.lm.size()); |
| assert(ctx.info[idx].exec.back().op.isTemp()); |
| bld.copy(Definition(exec, bld.lm), ctx.info[idx].exec.back().op); |
| } |
| |
| void |
| transition_to_Exact(exec_ctx& ctx, Builder bld, unsigned idx) |
| { |
| if (ctx.info[idx].exec.back().type & mask_type_exact) |
| return; |
| /* We can't remove the loop exec mask, because that can cause exec.size() to |
| * be less than num_exec_masks. The loop exec mask also needs to be kept |
| * around for various uses. */ |
| if ((ctx.info[idx].exec.back().type & mask_type_global) && |
| !(ctx.info[idx].exec.back().type & mask_type_loop)) { |
| ctx.info[idx].exec.pop_back(); |
| assert(ctx.info[idx].exec.back().type & mask_type_exact); |
| assert(ctx.info[idx].exec.back().op.size() == bld.lm.size()); |
| assert(ctx.info[idx].exec.back().op.isTemp()); |
| bld.copy(Definition(exec, bld.lm), ctx.info[idx].exec.back().op); |
| return; |
| } |
| /* otherwise, we create an exact mask and push to the stack */ |
| Operand wqm = ctx.info[idx].exec.back().op; |
| if (wqm == Operand(exec, bld.lm)) { |
| wqm = bld.sop1(Builder::s_and_saveexec, bld.def(bld.lm), bld.def(s1, scc), |
| Definition(exec, bld.lm), ctx.info[idx].exec[0].op, Operand(exec, bld.lm)); |
| } else { |
| bld.sop2(Builder::s_and, Definition(exec, bld.lm), bld.def(s1, scc), ctx.info[idx].exec[0].op, |
| wqm); |
| } |
| ctx.info[idx].exec.back().op = Operand(wqm); |
| ctx.info[idx].exec.emplace_back(Operand(exec, bld.lm), mask_type_exact); |
| } |
| |
| unsigned |
| add_coupling_code(exec_ctx& ctx, Block* block, std::vector<aco_ptr<Instruction>>& instructions) |
| { |
| unsigned idx = block->index; |
| Builder bld(ctx.program, &instructions); |
| Block::edge_vec& preds = block->linear_preds; |
| bool restore_exec = false; |
| |
| /* start block */ |
| if (preds.empty()) { |
| aco_ptr<Instruction>& startpgm = block->instructions[0]; |
| assert(startpgm->opcode == aco_opcode::p_startpgm); |
| bld.insert(std::move(startpgm)); |
| |
| unsigned count = 1; |
| while (block->instructions[count]->opcode == aco_opcode::p_init_scratch || |
| block->instructions[count]->opcode == aco_opcode::s_setprio) { |
| bld.insert(std::move(block->instructions[count])); |
| count++; |
| } |
| |
| Operand start_exec(exec, bld.lm); |
| |
| /* exec seems to need to be manually initialized with combined shaders */ |
| if (ctx.program->stage.num_sw_stages() > 1 || |
| ctx.program->stage.hw == AC_HW_NEXT_GEN_GEOMETRY_SHADER || |
| (ctx.program->stage.sw == SWStage::VS && |
| (ctx.program->stage.hw == AC_HW_HULL_SHADER || |
| ctx.program->stage.hw == AC_HW_LEGACY_GEOMETRY_SHADER)) || |
| (ctx.program->stage.sw == SWStage::TES && |
| ctx.program->stage.hw == AC_HW_LEGACY_GEOMETRY_SHADER)) { |
| start_exec = Operand::c32_or_c64(-1u, bld.lm == s2); |
| bld.copy(Definition(exec, bld.lm), start_exec); |
| } |
| |
| /* EXEC is automatically initialized by the HW for compute shaders. |
| * We know for sure exec is initially -1 when the shader always has full subgroups. |
| */ |
| if (ctx.program->stage == compute_cs && ctx.program->info.cs.uses_full_subgroups) |
| start_exec = Operand::c32_or_c64(-1u, bld.lm == s2); |
| |
| if (ctx.handle_wqm) { |
| ctx.info[idx].exec.emplace_back(start_exec, mask_type_global | mask_type_exact); |
| /* Initialize WQM already */ |
| transition_to_WQM(ctx, bld, idx); |
| } else { |
| uint8_t mask = mask_type_global; |
| if (ctx.program->needs_wqm) { |
| bld.sop1(Builder::s_wqm, Definition(exec, bld.lm), bld.def(s1, scc), |
| Operand(exec, bld.lm)); |
| mask |= mask_type_wqm; |
| } else { |
| mask |= mask_type_exact; |
| } |
| ctx.info[idx].exec.emplace_back(start_exec, mask); |
| } |
| |
| return count; |
| } |
| |
| /* loop entry block */ |
| if (block->kind & block_kind_loop_header) { |
| assert(preds[0] == idx - 1); |
| ctx.info[idx].exec = ctx.info[idx - 1].exec; |
| loop_info& info = ctx.loop.back(); |
| assert(ctx.info[idx].exec.size() == info.num_exec_masks); |
| |
| /* create ssa names for outer exec masks */ |
| if (info.has_discard && preds.size() > 1) { |
| aco_ptr<Instruction> phi; |
| for (int i = 0; i < info.num_exec_masks - 1; i++) { |
| phi.reset( |
| create_instruction(aco_opcode::p_linear_phi, Format::PSEUDO, preds.size(), 1)); |
| phi->definitions[0] = bld.def(bld.lm); |
| phi->operands[0] = ctx.info[preds[0]].exec[i].op; |
| ctx.info[idx].exec[i].op = bld.insert(std::move(phi)); |
| } |
| } |
| |
| ctx.info[idx].exec.back().type |= mask_type_loop; |
| |
| if (info.has_divergent_continue) { |
| /* create ssa name for loop active mask */ |
| aco_ptr<Instruction> phi{ |
| create_instruction(aco_opcode::p_linear_phi, Format::PSEUDO, preds.size(), 1)}; |
| phi->definitions[0] = bld.def(bld.lm); |
| phi->operands[0] = ctx.info[preds[0]].exec.back().op; |
| ctx.info[idx].exec.back().op = bld.insert(std::move(phi)); |
| |
| restore_exec = true; |
| uint8_t mask_type = ctx.info[idx].exec.back().type & (mask_type_wqm | mask_type_exact); |
| ctx.info[idx].exec.emplace_back(ctx.info[idx].exec.back().op, mask_type); |
| } |
| |
| } else if (block->kind & block_kind_loop_exit) { |
| Block* header = ctx.loop.back().loop_header; |
| loop_info& info = ctx.loop.back(); |
| |
| for (ASSERTED unsigned pred : preds) |
| assert(ctx.info[pred].exec.size() >= info.num_exec_masks); |
| |
| /* fill the loop header phis */ |
| Block::edge_vec& header_preds = header->linear_preds; |
| int instr_idx = 0; |
| if (info.has_discard && header_preds.size() > 1) { |
| while (instr_idx < info.num_exec_masks - 1) { |
| aco_ptr<Instruction>& phi = header->instructions[instr_idx]; |
| assert(phi->opcode == aco_opcode::p_linear_phi); |
| for (unsigned i = 1; i < phi->operands.size(); i++) |
| phi->operands[i] = ctx.info[header_preds[i]].exec[instr_idx].op; |
| instr_idx++; |
| } |
| } |
| |
| if (info.has_divergent_continue) { |
| aco_ptr<Instruction>& phi = header->instructions[instr_idx++]; |
| assert(phi->opcode == aco_opcode::p_linear_phi); |
| for (unsigned i = 1; i < phi->operands.size(); i++) |
| phi->operands[i] = ctx.info[header_preds[i]].exec[info.num_exec_masks - 1].op; |
| restore_exec = true; |
| } |
| |
| if (info.has_divergent_break) { |
| restore_exec = true; |
| /* Drop the loop active mask. */ |
| info.num_exec_masks--; |
| } |
| assert(!(block->kind & block_kind_top_level) || info.num_exec_masks <= 2); |
| |
| /* create the loop exit phis if not trivial */ |
| for (unsigned exec_idx = 0; exec_idx < info.num_exec_masks; exec_idx++) { |
| Operand same = ctx.info[preds[0]].exec[exec_idx].op; |
| uint8_t type = ctx.info[header_preds[0]].exec[exec_idx].type; |
| bool trivial = true; |
| |
| for (unsigned i = 1; i < preds.size() && trivial; i++) { |
| if (ctx.info[preds[i]].exec[exec_idx].op != same) |
| trivial = false; |
| } |
| |
| if (trivial) { |
| ctx.info[idx].exec.emplace_back(same, type); |
| } else { |
| /* create phi for loop footer */ |
| aco_ptr<Instruction> phi{ |
| create_instruction(aco_opcode::p_linear_phi, Format::PSEUDO, preds.size(), 1)}; |
| phi->definitions[0] = bld.def(bld.lm); |
| for (unsigned i = 0; i < phi->operands.size(); i++) |
| phi->operands[i] = ctx.info[preds[i]].exec[exec_idx].op; |
| ctx.info[idx].exec.emplace_back(bld.insert(std::move(phi)), type); |
| } |
| } |
| |
| assert(ctx.info[idx].exec.size() == info.num_exec_masks); |
| ctx.loop.pop_back(); |
| |
| } else if (preds.size() == 1) { |
| ctx.info[idx].exec = ctx.info[preds[0]].exec; |
| } else { |
| assert(preds.size() == 2); |
| assert(ctx.info[preds[0]].exec.size() == ctx.info[preds[1]].exec.size()); |
| |
| unsigned last = ctx.info[preds[0]].exec.size() - 1; |
| |
| /* create phis for diverged temporary exec masks */ |
| for (unsigned i = 0; i < last; i++) { |
| /* skip trivial phis */ |
| if (ctx.info[preds[0]].exec[i].op == ctx.info[preds[1]].exec[i].op) { |
| Operand op = ctx.info[preds[0]].exec[i].op; |
| /* discard/demote can change the state of the current exec mask */ |
| assert(!op.isTemp() || |
| ctx.info[preds[0]].exec[i].type == ctx.info[preds[1]].exec[i].type); |
| uint8_t mask = ctx.info[preds[0]].exec[i].type & ctx.info[preds[1]].exec[i].type; |
| ctx.info[idx].exec.emplace_back(op, mask); |
| continue; |
| } |
| |
| Operand phi = bld.pseudo(aco_opcode::p_linear_phi, bld.def(bld.lm), |
| ctx.info[preds[0]].exec[i].op, ctx.info[preds[1]].exec[i].op); |
| uint8_t mask_type = ctx.info[preds[0]].exec[i].type & ctx.info[preds[1]].exec[i].type; |
| ctx.info[idx].exec.emplace_back(phi, mask_type); |
| } |
| |
| if (block->kind & block_kind_merge) { |
| restore_exec = true; |
| } else { |
| /* The last mask is already in exec. */ |
| Operand current_exec = Operand(exec, bld.lm); |
| if (ctx.info[preds[0]].exec[last].op == ctx.info[preds[1]].exec[last].op) { |
| current_exec = ctx.info[preds[0]].exec[last].op; |
| } |
| uint8_t mask_type = |
| ctx.info[preds[0]].exec[last].type & ctx.info[preds[1]].exec[last].type; |
| ctx.info[idx].exec.emplace_back(current_exec, mask_type); |
| } |
| } |
| |
| unsigned i = 0; |
| while (block->instructions[i]->opcode == aco_opcode::p_phi || |
| block->instructions[i]->opcode == aco_opcode::p_linear_phi) { |
| bld.insert(std::move(block->instructions[i])); |
| i++; |
| } |
| |
| if (ctx.handle_wqm) { |
| /* End WQM handling if not needed anymore */ |
| if (block->kind & block_kind_top_level && ctx.info[idx].exec.size() == 2) { |
| if (block->instructions[i]->opcode == aco_opcode::p_end_wqm) { |
| ctx.info[idx].exec.back().type |= mask_type_global; |
| transition_to_Exact(ctx, bld, idx); |
| ctx.handle_wqm = false; |
| restore_exec = false; |
| i++; |
| } |
| } |
| } |
| |
| /* restore exec mask after divergent control flow */ |
| if (restore_exec) { |
| Operand restore = ctx.info[idx].exec.back().op; |
| assert(restore.size() == bld.lm.size()); |
| bld.copy(Definition(exec, bld.lm), restore); |
| } |
| |
| return i; |
| } |
| |
| /* Avoid live-range splits in Exact mode: |
| * Because the data register of atomic VMEM instructions |
| * is shared between src and dst, it might be necessary |
| * to create live-range splits during RA. |
| * Make the live-range splits explicit in WQM mode. |
| */ |
| void |
| handle_atomic_data(exec_ctx& ctx, Builder& bld, unsigned block_idx, aco_ptr<Instruction>& instr) |
| { |
| /* check if this is an atomic VMEM instruction */ |
| int idx = -1; |
| if (!instr->isVMEM() || instr->definitions.empty()) |
| return; |
| else if (instr->isMIMG()) |
| idx = instr->operands[2].isTemp() ? 2 : -1; |
| else if (instr->operands.size() == 4) |
| idx = 3; |
| |
| if (idx != -1) { |
| /* insert explicit copy of atomic data in WQM-mode */ |
| transition_to_WQM(ctx, bld, block_idx); |
| Temp data = instr->operands[idx].getTemp(); |
| data = bld.copy(bld.def(data.regClass()), data); |
| instr->operands[idx].setTemp(data); |
| } |
| } |
| |
| void |
| process_instructions(exec_ctx& ctx, Block* block, std::vector<aco_ptr<Instruction>>& instructions, |
| unsigned idx) |
| { |
| block_info& info = ctx.info[block->index]; |
| WQMState state; |
| if (info.exec.back().type & mask_type_wqm) { |
| state = WQM; |
| } else { |
| assert(!ctx.handle_wqm || info.exec.back().type & mask_type_exact); |
| state = Exact; |
| } |
| |
| Builder bld(ctx.program, &instructions); |
| |
| for (; idx < block->instructions.size(); idx++) { |
| aco_ptr<Instruction> instr = std::move(block->instructions[idx]); |
| |
| WQMState needs = ctx.handle_wqm ? get_instr_needs(instr) : Unspecified; |
| |
| if (needs == WQM && state != WQM) { |
| transition_to_WQM(ctx, bld, block->index); |
| state = WQM; |
| } else if (needs == Exact) { |
| if (ctx.handle_wqm) |
| handle_atomic_data(ctx, bld, block->index, instr); |
| transition_to_Exact(ctx, bld, block->index); |
| state = Exact; |
| } |
| |
| if (instr->opcode == aco_opcode::p_discard_if) { |
| Operand current_exec = Operand(exec, bld.lm); |
| |
| if (block->instructions[idx + 1]->opcode == aco_opcode::p_end_wqm) { |
| /* Transition to Exact without extra instruction. */ |
| info.exec.resize(1); |
| assert(info.exec[0].type == (mask_type_exact | mask_type_global)); |
| current_exec = info.exec[0].op; |
| info.exec[0].op = Operand(exec, bld.lm); |
| state = Exact; |
| } else if (info.exec.size() >= 2 && ctx.handle_wqm) { |
| /* Preserve the WQM mask */ |
| info.exec[1].type &= ~mask_type_global; |
| } |
| |
| Temp cond; |
| if (instr->operands[0].isConstant()) { |
| assert(instr->operands[0].constantValue() == -1u); |
| /* save condition and set exec to zero */ |
| cond = bld.sop1(Builder::s_and_saveexec, bld.def(bld.lm), bld.def(s1, scc), |
| Definition(exec, bld.lm), Operand::zero(), Operand(exec, bld.lm)); |
| } else { |
| cond = instr->operands[0].getTemp(); |
| /* discard from current exec */ |
| bld.sop2(Builder::s_andn2, Definition(exec, bld.lm), bld.def(s1, scc), current_exec, |
| cond); |
| } |
| |
| if (info.exec.size() == 1) { |
| instr->operands[0] = Operand(exec, bld.lm); |
| } else { |
| /* discard from inner to outer exec mask on stack */ |
| int num = info.exec.size() - 2; |
| Temp exit_cond; |
| for (int i = num; i >= 0; i--) { |
| Instruction* andn2 = bld.sop2(Builder::s_andn2, bld.def(bld.lm), bld.def(s1, scc), |
| info.exec[i].op, cond); |
| info.exec[i].op = Operand(andn2->definitions[0].getTemp()); |
| exit_cond = andn2->definitions[1].getTemp(); |
| } |
| instr->operands[0] = bld.scc(exit_cond); |
| } |
| |
| info.exec.back().op = Operand(exec, bld.lm); |
| instr->opcode = aco_opcode::p_exit_early_if_not; |
| assert(!ctx.handle_wqm || (info.exec[0].type & mask_type_wqm) == 0); |
| } else if (instr->opcode == aco_opcode::p_is_helper) { |
| Definition dst = instr->definitions[0]; |
| assert(dst.size() == bld.lm.size()); |
| if (state == Exact) { |
| instr.reset(create_instruction(bld.w64or32(Builder::s_mov), Format::SOP1, 1, 1)); |
| instr->operands[0] = Operand::zero(); |
| instr->definitions[0] = dst; |
| } else { |
| exec_info& exact_mask = info.exec[0]; |
| assert(exact_mask.type & mask_type_exact); |
| |
| instr.reset(create_instruction(bld.w64or32(Builder::s_andn2), Format::SOP2, 2, 2)); |
| instr->operands[0] = Operand(exec, bld.lm); /* current exec */ |
| instr->operands[1] = Operand(exact_mask.op); |
| instr->definitions[0] = dst; |
| instr->definitions[1] = bld.def(s1, scc); |
| } |
| } else if (instr->opcode == aco_opcode::p_demote_to_helper) { |
| assert((info.exec[0].type & mask_type_exact) && (info.exec[0].type & mask_type_global)); |
| |
| const bool nested_cf = !(info.exec.back().type & mask_type_global); |
| if (ctx.handle_wqm && state == Exact && nested_cf) { |
| /* Transition back to WQM without extra instruction. */ |
| info.exec.pop_back(); |
| state = WQM; |
| } else if (block->instructions[idx + 1]->opcode == aco_opcode::p_end_wqm) { |
| /* Transition to Exact without extra instruction. */ |
| info.exec.resize(1); |
| state = Exact; |
| } else if (nested_cf) { |
| /* Save curent exec temporarily. */ |
| info.exec.back().op = bld.copy(bld.def(bld.lm), Operand(exec, bld.lm)); |
| } else { |
| info.exec.back().op = Operand(exec, bld.lm); |
| } |
| |
| /* Remove invocations from global exact mask. */ |
| Definition def = state == Exact ? Definition(exec, bld.lm) : bld.def(bld.lm); |
| Operand src = instr->operands[0].isConstant() ? Operand(exec, bld.lm) : instr->operands[0]; |
| |
| bld.sop2(Builder::s_andn2, def, bld.def(s1, scc), info.exec[0].op, src); |
| info.exec[0].op = def.isTemp() ? Operand(def.getTemp()) : Operand(exec, bld.lm); |
| |
| /* Update global WQM mask and store in exec. */ |
| if (state == WQM) { |
| assert(info.exec.size() > 1); |
| bld.sop1(Builder::s_wqm, Definition(exec, bld.lm), bld.def(s1, scc), def.getTemp()); |
| } |
| |
| /* End shader if global mask is zero. */ |
| instr->opcode = aco_opcode::p_exit_early_if_not; |
| instr->operands[0] = Operand(exec, bld.lm); |
| bld.insert(std::move(instr)); |
| |
| /* Update all other exec masks. */ |
| if (nested_cf) { |
| const unsigned global_idx = state == WQM ? 1 : 0; |
| for (unsigned i = global_idx + 1; i < info.exec.size() - 1; i++) { |
| info.exec[i].op = bld.sop2(Builder::s_and, bld.def(bld.lm), bld.def(s1, scc), |
| info.exec[i].op, Operand(exec, bld.lm)); |
| } |
| /* Update current exec and save WQM mask. */ |
| info.exec[global_idx].op = |
| bld.sop1(Builder::s_and_saveexec, bld.def(bld.lm), bld.def(s1, scc), |
| Definition(exec, bld.lm), info.exec.back().op, Operand(exec, bld.lm)); |
| info.exec.back().op = Operand(exec, bld.lm); |
| } |
| continue; |
| |
| } else if (instr->opcode == aco_opcode::p_elect) { |
| bool all_lanes_enabled = info.exec.back().op.constantEquals(-1u); |
| Definition dst = instr->definitions[0]; |
| |
| if (all_lanes_enabled) { |
| bld.copy(Definition(dst), Operand::c32_or_c64(1u, dst.size() == 2)); |
| } else { |
| Temp first_lane_idx = bld.sop1(Builder::s_ff1_i32, bld.def(s1), Operand(exec, bld.lm)); |
| bld.sop2(Builder::s_lshl, Definition(dst), bld.def(s1, scc), |
| Operand::c32_or_c64(1u, dst.size() == 2), Operand(first_lane_idx)); |
| } |
| continue; |
| } else if (instr->opcode == aco_opcode::p_end_wqm) { |
| assert(block->kind & block_kind_top_level); |
| assert(info.exec.size() <= 2); |
| /* This instruction indicates the end of WQM mode. */ |
| info.exec.back().type |= mask_type_global; |
| transition_to_Exact(ctx, bld, block->index); |
| state = Exact; |
| ctx.handle_wqm = false; |
| continue; |
| } |
| |
| bld.insert(std::move(instr)); |
| } |
| } |
| |
| void |
| add_branch_code(exec_ctx& ctx, Block* block) |
| { |
| unsigned idx = block->index; |
| Builder bld(ctx.program, block); |
| |
| if (block->linear_succs.empty()) |
| return; |
| |
| if (block->kind & block_kind_loop_preheader) { |
| /* collect information about the succeeding loop */ |
| bool has_divergent_break = false; |
| bool has_divergent_continue = false; |
| bool has_discard = false; |
| unsigned loop_nest_depth = ctx.program->blocks[idx + 1].loop_nest_depth; |
| |
| for (unsigned i = idx + 1; ctx.program->blocks[i].loop_nest_depth >= loop_nest_depth; i++) { |
| Block& loop_block = ctx.program->blocks[i]; |
| |
| if (loop_block.kind & block_kind_uses_discard) |
| has_discard = true; |
| if (loop_block.loop_nest_depth != loop_nest_depth) |
| continue; |
| |
| if (loop_block.kind & block_kind_uniform) |
| continue; |
| else if (loop_block.kind & block_kind_break) |
| has_divergent_break = true; |
| else if (loop_block.kind & block_kind_continue) |
| has_divergent_continue = true; |
| } |
| |
| if (has_divergent_break) { |
| /* save restore exec mask */ |
| const Operand& current_exec = ctx.info[idx].exec.back().op; |
| if (!current_exec.isTemp() && !current_exec.isConstant()) { |
| bld.reset(bld.instructions, std::prev(bld.instructions->end())); |
| Operand restore = bld.copy(bld.def(bld.lm), Operand(exec, bld.lm)); |
| ctx.info[idx].exec.back().op = restore; |
| bld.reset(bld.instructions); |
| } |
| uint8_t mask = ctx.info[idx].exec.back().type & (mask_type_wqm | mask_type_exact); |
| ctx.info[idx].exec.emplace_back(Operand(exec, bld.lm), mask); |
| } |
| unsigned num_exec_masks = ctx.info[idx].exec.size(); |
| |
| ctx.loop.emplace_back(&ctx.program->blocks[block->linear_succs[0]], num_exec_masks, |
| has_divergent_break, has_divergent_continue, has_discard); |
| |
| Pseudo_branch_instruction& branch = block->instructions.back()->branch(); |
| branch.target[0] = block->linear_succs[0]; |
| } else if (block->kind & block_kind_continue_or_break) { |
| assert(ctx.program->blocks[ctx.program->blocks[block->linear_succs[1]].linear_succs[0]].kind & |
| block_kind_loop_header); |
| assert(ctx.program->blocks[ctx.program->blocks[block->linear_succs[0]].linear_succs[0]].kind & |
| block_kind_loop_exit); |
| assert(block->instructions.back()->opcode == aco_opcode::p_branch); |
| block->instructions.pop_back(); |
| |
| bool need_parallelcopy = false; |
| while (!(ctx.info[idx].exec.back().type & mask_type_loop)) { |
| ctx.info[idx].exec.pop_back(); |
| need_parallelcopy = true; |
| } |
| |
| if (need_parallelcopy) |
| bld.copy(Definition(exec, bld.lm), ctx.info[idx].exec.back().op); |
| bld.branch(aco_opcode::p_cbranch_nz, Operand(exec, bld.lm), block->linear_succs[1], |
| block->linear_succs[0]); |
| } else if (block->kind & block_kind_uniform) { |
| Pseudo_branch_instruction& branch = block->instructions.back()->branch(); |
| if (branch.opcode == aco_opcode::p_branch) { |
| branch.target[0] = block->linear_succs[0]; |
| } else { |
| branch.target[0] = block->linear_succs[1]; |
| branch.target[1] = block->linear_succs[0]; |
| } |
| } else if (block->kind & block_kind_branch) { |
| // orig = s_and_saveexec_b64 |
| assert(block->linear_succs.size() == 2); |
| assert(block->instructions.back()->opcode == aco_opcode::p_cbranch_z); |
| Temp cond = block->instructions.back()->operands[0].getTemp(); |
| aco_ptr<Instruction> branch = std::move(block->instructions.back()); |
| block->instructions.pop_back(); |
| |
| uint8_t mask_type = ctx.info[idx].exec.back().type & (mask_type_wqm | mask_type_exact); |
| if (ctx.info[idx].exec.back().op.constantEquals(-1u)) { |
| bld.copy(Definition(exec, bld.lm), cond); |
| } else if (ctx.info[idx].exec.back().op.isTemp()) { |
| bld.sop2(Builder::s_and, Definition(exec, bld.lm), bld.def(s1, scc), cond, |
| Operand(exec, bld.lm)); |
| } else { |
| Temp old_exec = bld.sop1(Builder::s_and_saveexec, bld.def(bld.lm), bld.def(s1, scc), |
| Definition(exec, bld.lm), cond, Operand(exec, bld.lm)); |
| |
| ctx.info[idx].exec.back().op = Operand(old_exec); |
| } |
| |
| /* add next current exec to the stack */ |
| ctx.info[idx].exec.emplace_back(Operand(exec, bld.lm), mask_type); |
| |
| Builder::Result r = bld.branch(aco_opcode::p_cbranch_z, Operand(exec, bld.lm), |
| block->linear_succs[1], block->linear_succs[0]); |
| r->branch().rarely_taken = branch->branch().rarely_taken; |
| r->branch().never_taken = branch->branch().never_taken; |
| } else if (block->kind & block_kind_invert) { |
| // exec = s_andn2_b64 (original_exec, exec) |
| assert(block->instructions.back()->opcode == aco_opcode::p_branch); |
| aco_ptr<Instruction> branch = std::move(block->instructions.back()); |
| block->instructions.pop_back(); |
| assert(ctx.info[idx].exec.size() >= 2); |
| Operand orig_exec = ctx.info[idx].exec[ctx.info[idx].exec.size() - 2].op; |
| bld.sop2(Builder::s_andn2, Definition(exec, bld.lm), bld.def(s1, scc), orig_exec, |
| Operand(exec, bld.lm)); |
| |
| Builder::Result r = bld.branch(aco_opcode::p_cbranch_z, Operand(exec, bld.lm), |
| block->linear_succs[1], block->linear_succs[0]); |
| r->branch().rarely_taken = branch->branch().rarely_taken; |
| r->branch().never_taken = branch->branch().never_taken; |
| } else if (block->kind & block_kind_break) { |
| // loop_mask = s_andn2_b64 (loop_mask, exec) |
| assert(block->instructions.back()->opcode == aco_opcode::p_branch); |
| block->instructions.pop_back(); |
| |
| Temp cond = Temp(); |
| for (int exec_idx = ctx.info[idx].exec.size() - 2; exec_idx >= 0; exec_idx--) { |
| cond = bld.tmp(s1); |
| Operand exec_mask = ctx.info[idx].exec[exec_idx].op; |
| exec_mask = bld.sop2(Builder::s_andn2, bld.def(bld.lm), bld.scc(Definition(cond)), |
| exec_mask, Operand(exec, bld.lm)); |
| ctx.info[idx].exec[exec_idx].op = exec_mask; |
| if (ctx.info[idx].exec[exec_idx].type & mask_type_loop) |
| break; |
| } |
| |
| /* check if the successor is the merge block, otherwise set exec to 0 */ |
| // TODO: this could be done better by directly branching to the merge block |
| unsigned succ_idx = ctx.program->blocks[block->linear_succs[1]].linear_succs[0]; |
| Block& succ = ctx.program->blocks[succ_idx]; |
| if (!(succ.kind & block_kind_invert || succ.kind & block_kind_merge)) { |
| bld.copy(Definition(exec, bld.lm), Operand::zero(bld.lm.bytes())); |
| } |
| |
| bld.branch(aco_opcode::p_cbranch_nz, bld.scc(cond), block->linear_succs[1], |
| block->linear_succs[0]); |
| } else if (block->kind & block_kind_continue) { |
| assert(block->instructions.back()->opcode == aco_opcode::p_branch); |
| block->instructions.pop_back(); |
| |
| Temp cond = Temp(); |
| for (int exec_idx = ctx.info[idx].exec.size() - 2; exec_idx >= 0; exec_idx--) { |
| if (ctx.info[idx].exec[exec_idx].type & mask_type_loop) |
| break; |
| cond = bld.tmp(s1); |
| Operand exec_mask = ctx.info[idx].exec[exec_idx].op; |
| exec_mask = bld.sop2(Builder::s_andn2, bld.def(bld.lm), bld.scc(Definition(cond)), |
| exec_mask, Operand(exec, bld.lm)); |
| ctx.info[idx].exec[exec_idx].op = exec_mask; |
| } |
| assert(cond != Temp()); |
| |
| /* check if the successor is the merge block, otherwise set exec to 0 */ |
| // TODO: this could be done better by directly branching to the merge block |
| unsigned succ_idx = ctx.program->blocks[block->linear_succs[1]].linear_succs[0]; |
| Block& succ = ctx.program->blocks[succ_idx]; |
| if (!(succ.kind & block_kind_invert || succ.kind & block_kind_merge)) { |
| bld.copy(Definition(exec, bld.lm), Operand::zero(bld.lm.bytes())); |
| } |
| |
| bld.branch(aco_opcode::p_cbranch_nz, bld.scc(cond), block->linear_succs[1], |
| block->linear_succs[0]); |
| } else { |
| unreachable("unknown/invalid block type"); |
| } |
| } |
| |
| void |
| process_block(exec_ctx& ctx, Block* block) |
| { |
| std::vector<aco_ptr<Instruction>> instructions; |
| instructions.reserve(block->instructions.size()); |
| |
| unsigned idx = add_coupling_code(ctx, block, instructions); |
| |
| assert(!block->linear_succs.empty() || ctx.info[block->index].exec.size() <= 2); |
| |
| process_instructions(ctx, block, instructions, idx); |
| |
| block->instructions = std::move(instructions); |
| |
| add_branch_code(ctx, block); |
| } |
| |
| } /* end namespace */ |
| |
| void |
| insert_exec_mask(Program* program) |
| { |
| exec_ctx ctx(program); |
| |
| if (program->needs_wqm && program->needs_exact) |
| ctx.handle_wqm = true; |
| |
| for (Block& block : program->blocks) |
| process_block(ctx, &block); |
| } |
| |
| } // namespace aco |
