/* * Copyright © 2019 Valve Corporation * * SPDX-License-Identifier: MIT */ #include "aco_builder.h" #include "aco_ir.h" #include "util/bitset.h" #include #include #include #include #include namespace aco { namespace { struct State { Program* program; Block* block; std::vector> old_instructions; }; struct NOP_ctx_gfx6 { void join(const NOP_ctx_gfx6& other) { set_vskip_mode_then_vector = MAX2(set_vskip_mode_then_vector, other.set_vskip_mode_then_vector); valu_wr_vcc_then_div_fmas = MAX2(valu_wr_vcc_then_div_fmas, other.valu_wr_vcc_then_div_fmas); salu_wr_m0_then_gds_msg_ttrace = MAX2(salu_wr_m0_then_gds_msg_ttrace, other.salu_wr_m0_then_gds_msg_ttrace); valu_wr_exec_then_dpp = MAX2(valu_wr_exec_then_dpp, other.valu_wr_exec_then_dpp); salu_wr_m0_then_lds = MAX2(salu_wr_m0_then_lds, other.salu_wr_m0_then_lds); salu_wr_m0_then_moverel = MAX2(salu_wr_m0_then_moverel, other.salu_wr_m0_then_moverel); setreg_then_getsetreg = MAX2(setreg_then_getsetreg, other.setreg_then_getsetreg); vmem_store_then_wr_data |= other.vmem_store_then_wr_data; smem_clause |= other.smem_clause; smem_write |= other.smem_write; for (unsigned i = 0; i < BITSET_WORDS(128); i++) { smem_clause_read_write[i] |= other.smem_clause_read_write[i]; smem_clause_write[i] |= other.smem_clause_write[i]; } } bool operator==(const NOP_ctx_gfx6& other) { return set_vskip_mode_then_vector == other.set_vskip_mode_then_vector && valu_wr_vcc_then_div_fmas == other.valu_wr_vcc_then_div_fmas && vmem_store_then_wr_data == other.vmem_store_then_wr_data && salu_wr_m0_then_gds_msg_ttrace == other.salu_wr_m0_then_gds_msg_ttrace && valu_wr_exec_then_dpp == other.valu_wr_exec_then_dpp && salu_wr_m0_then_lds == other.salu_wr_m0_then_lds && salu_wr_m0_then_moverel == other.salu_wr_m0_then_moverel && setreg_then_getsetreg == other.setreg_then_getsetreg && smem_clause == other.smem_clause && smem_write == other.smem_write && BITSET_EQUAL(smem_clause_read_write, other.smem_clause_read_write) && BITSET_EQUAL(smem_clause_write, other.smem_clause_write); } void add_wait_states(unsigned amount) { if ((set_vskip_mode_then_vector -= amount) < 0) set_vskip_mode_then_vector = 0; if ((valu_wr_vcc_then_div_fmas -= amount) < 0) valu_wr_vcc_then_div_fmas = 0; if ((salu_wr_m0_then_gds_msg_ttrace -= amount) < 0) salu_wr_m0_then_gds_msg_ttrace = 0; if ((valu_wr_exec_then_dpp -= amount) < 0) valu_wr_exec_then_dpp = 0; if ((salu_wr_m0_then_lds -= amount) < 0) salu_wr_m0_then_lds = 0; if ((salu_wr_m0_then_moverel -= amount) < 0) salu_wr_m0_then_moverel = 0; if ((setreg_then_getsetreg -= amount) < 0) setreg_then_getsetreg = 0; vmem_store_then_wr_data.reset(); } /* setting MODE.vskip and then any vector op requires 2 wait states */ int8_t set_vskip_mode_then_vector = 0; /* VALU writing VCC followed by v_div_fmas require 4 wait states */ int8_t valu_wr_vcc_then_div_fmas = 0; /* SALU writing M0 followed by GDS, s_sendmsg or s_ttrace_data requires 1 wait state */ int8_t salu_wr_m0_then_gds_msg_ttrace = 0; /* VALU writing EXEC followed by DPP requires 5 wait states */ int8_t valu_wr_exec_then_dpp = 0; /* SALU writing M0 followed by some LDS instructions requires 1 wait state on GFX10 */ int8_t salu_wr_m0_then_lds = 0; /* SALU writing M0 followed by s_moverel requires 1 wait state on GFX9 */ int8_t salu_wr_m0_then_moverel = 0; /* s_setreg followed by a s_getreg/s_setreg of the same register needs 2 wait states * currently we don't look at the actual register */ int8_t setreg_then_getsetreg = 0; /* some memory instructions writing >64bit followed by a instructions * writing the VGPRs holding the writedata requires 1 wait state */ std::bitset<256> vmem_store_then_wr_data; /* we break up SMEM clauses that contain stores or overwrite an * operand/definition of another instruction in the clause */ bool smem_clause = false; bool smem_write = false; BITSET_DECLARE(smem_clause_read_write, 128) = {0}; BITSET_DECLARE(smem_clause_write, 128) = {0}; }; struct NOP_ctx_gfx10 { bool has_VOPC_write_exec = false; bool has_nonVALU_exec_read = false; bool has_VMEM = false; bool has_branch_after_VMEM = false; bool has_DS = false; bool has_branch_after_DS = false; bool has_NSA_MIMG = false; bool has_writelane = false; std::bitset<128> sgprs_read_by_VMEM; std::bitset<128> sgprs_read_by_VMEM_store; std::bitset<128> sgprs_read_by_DS; std::bitset<128> sgprs_read_by_SMEM; void join(const NOP_ctx_gfx10& other) { has_VOPC_write_exec |= other.has_VOPC_write_exec; has_nonVALU_exec_read |= other.has_nonVALU_exec_read; has_VMEM |= other.has_VMEM; has_branch_after_VMEM |= other.has_branch_after_VMEM; has_DS |= other.has_DS; has_branch_after_DS |= other.has_branch_after_DS; has_NSA_MIMG |= other.has_NSA_MIMG; has_writelane |= other.has_writelane; sgprs_read_by_VMEM |= other.sgprs_read_by_VMEM; sgprs_read_by_DS |= other.sgprs_read_by_DS; sgprs_read_by_VMEM_store |= other.sgprs_read_by_VMEM_store; sgprs_read_by_SMEM |= other.sgprs_read_by_SMEM; } bool operator==(const NOP_ctx_gfx10& other) { return has_VOPC_write_exec == other.has_VOPC_write_exec && has_nonVALU_exec_read == other.has_nonVALU_exec_read && has_VMEM == other.has_VMEM && has_branch_after_VMEM == other.has_branch_after_VMEM && has_DS == other.has_DS && has_branch_after_DS == other.has_branch_after_DS && has_NSA_MIMG == other.has_NSA_MIMG && has_writelane == other.has_writelane && sgprs_read_by_VMEM == other.sgprs_read_by_VMEM && sgprs_read_by_DS == other.sgprs_read_by_DS && sgprs_read_by_VMEM_store == other.sgprs_read_by_VMEM_store && sgprs_read_by_SMEM == other.sgprs_read_by_SMEM; } }; template struct RegCounterMap { void inc() { base++; } void set(PhysReg reg) { update(reg, 0); } uint8_t get(PhysReg reg) { if (present.test(reg.reg() & 0x7F)) { for (entry& e : list) { if (e.reg == reg.reg()) return MIN2(base - e.val, Max); } } return Max; } void reset() { present.reset(); list.clear(); base = 0; } bool empty() { for (entry& e : list) { if (base - e.val < Max) return false; } return true; } void join_min(const RegCounterMap& other) { for (const entry& e : other.list) { int idx = other.base - e.val; if (idx >= Max) continue; update(e.reg, idx); } } void update(uint16_t reg, int idx) { int16_t val = base - idx; for (entry& e : list) { if (e.reg == reg) { e.val = MAX2(e.val, val); return; } } list.push_back(entry{reg, val}); present.set(reg & 0x7F); } bool operator==(const RegCounterMap& other) const { /* Two maps with different bases could also be equal, but for our use case, * i.e. checking for changes at loop headers, this is sufficient since we * always join the predecessors into an empty map with base=0. */ return base == other.base && list == other.list; } private: struct entry { uint16_t reg; int16_t val; bool operator!=(const entry& other) const { return reg != other.reg || val != other.val; } }; std::bitset<128> present; small_vec list; int base = 0; }; struct NOP_ctx_gfx11 { /* VcmpxPermlaneHazard */ bool has_Vcmpx = false; /* LdsDirectVMEMHazard */ std::bitset<256> vgpr_used_by_vmem_load; std::bitset<256> vgpr_used_by_vmem_sample; std::bitset<256> vgpr_used_by_vmem_bvh; std::bitset<256> vgpr_used_by_vmem_store; std::bitset<256> vgpr_used_by_ds; /* VALUTransUseHazard */ RegCounterMap<6> valu_since_wr_by_trans; RegCounterMap<2> trans_since_wr_by_trans; /* VALUMaskWriteHazard */ std::bitset<128> sgpr_read_by_valu_as_lanemask; std::bitset<128> sgpr_read_by_valu_as_lanemask_then_wr_by_salu; /* WMMAHazards */ std::bitset<256> vgpr_written_by_wmma; /* VALUReadSGPRHazard */ std::bitset sgpr_read_by_valu; /* SGPR pairs, excluding null, exec, m0 and scc */ RegCounterMap<11> sgpr_read_by_valu_then_wr_by_salu; void join(const NOP_ctx_gfx11& other) { has_Vcmpx |= other.has_Vcmpx; vgpr_used_by_vmem_load |= other.vgpr_used_by_vmem_load; vgpr_used_by_vmem_sample |= other.vgpr_used_by_vmem_sample; vgpr_used_by_vmem_bvh |= other.vgpr_used_by_vmem_bvh; vgpr_used_by_vmem_store |= other.vgpr_used_by_vmem_store; vgpr_used_by_ds |= other.vgpr_used_by_ds; valu_since_wr_by_trans.join_min(other.valu_since_wr_by_trans); trans_since_wr_by_trans.join_min(other.trans_since_wr_by_trans); sgpr_read_by_valu_as_lanemask |= other.sgpr_read_by_valu_as_lanemask; sgpr_read_by_valu_as_lanemask_then_wr_by_salu |= other.sgpr_read_by_valu_as_lanemask_then_wr_by_salu; vgpr_written_by_wmma |= other.vgpr_written_by_wmma; sgpr_read_by_valu |= other.sgpr_read_by_valu; sgpr_read_by_valu_then_wr_by_salu.join_min(other.sgpr_read_by_valu_then_wr_by_salu); } bool operator==(const NOP_ctx_gfx11& other) { return has_Vcmpx == other.has_Vcmpx && vgpr_used_by_vmem_load == other.vgpr_used_by_vmem_load && vgpr_used_by_vmem_sample == other.vgpr_used_by_vmem_sample && vgpr_used_by_vmem_bvh == other.vgpr_used_by_vmem_bvh && vgpr_used_by_vmem_store == other.vgpr_used_by_vmem_store && vgpr_used_by_ds == other.vgpr_used_by_ds && valu_since_wr_by_trans == other.valu_since_wr_by_trans && trans_since_wr_by_trans == other.trans_since_wr_by_trans && sgpr_read_by_valu_as_lanemask == other.sgpr_read_by_valu_as_lanemask && sgpr_read_by_valu_as_lanemask_then_wr_by_salu == other.sgpr_read_by_valu_as_lanemask_then_wr_by_salu && vgpr_written_by_wmma == other.vgpr_written_by_wmma && sgpr_read_by_valu == other.sgpr_read_by_valu && sgpr_read_by_valu_then_wr_by_salu == other.sgpr_read_by_valu_then_wr_by_salu; } }; int get_wait_states(aco_ptr& instr) { if (instr->opcode == aco_opcode::s_nop) return instr->salu().imm + 1; else if (instr->opcode == aco_opcode::p_constaddr) return 3; /* lowered to 3 instructions in the assembler */ else return 1; } bool regs_intersect(PhysReg a_reg, unsigned a_size, PhysReg b_reg, unsigned b_size) { return a_reg > b_reg ? (a_reg - b_reg < b_size) : (b_reg - a_reg < a_size); } template &)> void search_backwards_internal(State& state, GlobalState& global_state, BlockState block_state, Block* block, bool start_at_end) { if (block == state.block && start_at_end) { /* If it's the current block, block->instructions is incomplete. */ for (int pred_idx = state.old_instructions.size() - 1; pred_idx >= 0; pred_idx--) { aco_ptr& instr = state.old_instructions[pred_idx]; if (!instr) break; /* Instruction has been moved to block->instructions. */ if (instr_cb(global_state, block_state, instr)) return; } } for (int pred_idx = block->instructions.size() - 1; pred_idx >= 0; pred_idx--) { if (instr_cb(global_state, block_state, block->instructions[pred_idx])) return; } PRAGMA_DIAGNOSTIC_PUSH PRAGMA_DIAGNOSTIC_IGNORED(-Waddress) if (block_cb != nullptr && !block_cb(global_state, block_state, block)) return; PRAGMA_DIAGNOSTIC_POP for (unsigned lin_pred : block->linear_preds) { search_backwards_internal( state, global_state, block_state, &state.program->blocks[lin_pred], true); } } template &)> void search_backwards(State& state, GlobalState& global_state, BlockState& block_state) { search_backwards_internal( state, global_state, block_state, state.block, false); } struct HandleRawHazardGlobalState { PhysReg reg; int nops_needed; }; struct HandleRawHazardBlockState { uint32_t mask; int nops_needed; }; template bool handle_raw_hazard_instr(HandleRawHazardGlobalState& global_state, HandleRawHazardBlockState& block_state, aco_ptr& pred) { unsigned mask_size = util_last_bit(block_state.mask); uint32_t writemask = 0; for (Definition& def : pred->definitions) { if (regs_intersect(global_state.reg, mask_size, def.physReg(), def.size())) { unsigned start = def.physReg() > global_state.reg ? def.physReg() - global_state.reg : 0; unsigned end = MIN2(mask_size, start + def.size()); writemask |= u_bit_consecutive(start, end - start); } } bool is_hazard = writemask != 0 && ((pred->isVALU() && Valu) || (pred->isVINTRP() && Vintrp) || (pred->isSALU() && Salu)); if (is_hazard) { global_state.nops_needed = MAX2(global_state.nops_needed, block_state.nops_needed); return true; } block_state.mask &= ~writemask; block_state.nops_needed = MAX2(block_state.nops_needed - get_wait_states(pred), 0); if (block_state.mask == 0) block_state.nops_needed = 0; return block_state.nops_needed == 0; } template void handle_raw_hazard(State& state, int* NOPs, int min_states, Operand op) { if (*NOPs >= min_states) return; HandleRawHazardGlobalState global = {op.physReg(), 0}; HandleRawHazardBlockState block = {u_bit_consecutive(0, op.size()), min_states}; /* Loops require branch instructions, which count towards the wait * states. So even with loops this should finish unless nops_needed is some * huge value. */ search_backwards>(state, global, block); *NOPs = MAX2(*NOPs, global.nops_needed); } static auto handle_valu_then_read_hazard = handle_raw_hazard; static auto handle_vintrp_then_read_hazard = handle_raw_hazard; static auto handle_valu_salu_then_read_hazard = handle_raw_hazard; void set_bitset_range(BITSET_WORD* words, unsigned start, unsigned size) { unsigned end = start + size - 1; unsigned start_mod = start % BITSET_WORDBITS; if (start_mod + size <= BITSET_WORDBITS) { BITSET_SET_RANGE_INSIDE_WORD(words, start, end); } else { unsigned first_size = BITSET_WORDBITS - start_mod; set_bitset_range(words, start, BITSET_WORDBITS - start_mod); set_bitset_range(words, start + first_size, size - first_size); } } bool test_bitset_range(BITSET_WORD* words, unsigned start, unsigned size) { unsigned end = start + size - 1; unsigned start_mod = start % BITSET_WORDBITS; if (start_mod + size <= BITSET_WORDBITS) { return BITSET_TEST_RANGE(words, start, end); } else { unsigned first_size = BITSET_WORDBITS - start_mod; return test_bitset_range(words, start, BITSET_WORDBITS - start_mod) || test_bitset_range(words, start + first_size, size - first_size); } } /* A SMEM clause is any group of consecutive SMEM instructions. The * instructions in this group may return out of order and/or may be replayed. * * To fix this potential hazard correctly, we have to make sure that when a * clause has more than one instruction, no instruction in the clause writes * to a register that is read by another instruction in the clause (including * itself). In this case, we have to break the SMEM clause by inserting non * SMEM instructions. * * SMEM clauses are only present on GFX8+, and only matter when XNACK is set. */ void handle_smem_clause_hazards(Program* program, NOP_ctx_gfx6& ctx, aco_ptr& instr, int* NOPs) { /* break off from previous SMEM clause if needed */ if (!*NOPs & (ctx.smem_clause || ctx.smem_write)) { /* Don't allow clauses with store instructions since the clause's * instructions may use the same address. */ if (ctx.smem_write || instr->definitions.empty() || instr_info.is_atomic[(unsigned)instr->opcode]) { *NOPs = 1; } else if (program->dev.xnack_enabled) { for (Operand op : instr->operands) { if (!op.isConstant() && test_bitset_range(ctx.smem_clause_write, op.physReg(), op.size())) { *NOPs = 1; break; } } Definition def = instr->definitions[0]; if (!*NOPs && test_bitset_range(ctx.smem_clause_read_write, def.physReg(), def.size())) *NOPs = 1; } } } /* TODO: we don't handle accessing VCC using the actual SGPR instead of using the alias */ void handle_instruction_gfx6(State& state, NOP_ctx_gfx6& ctx, aco_ptr& instr, std::vector>& new_instructions) { /* check hazards */ int NOPs = 0; if (instr->isSMEM()) { if (state.program->gfx_level == GFX6) { /* A read of an SGPR by SMRD instruction requires 4 wait states * when the SGPR was written by a VALU instruction. According to LLVM, * there is also an undocumented hardware behavior when the buffer * descriptor is written by a SALU instruction */ for (unsigned i = 0; i < instr->operands.size(); i++) { Operand op = instr->operands[i]; if (op.isConstant()) continue; bool is_buffer_desc = i == 0 && op.size() > 2; if (is_buffer_desc) handle_valu_salu_then_read_hazard(state, &NOPs, 4, op); else handle_valu_then_read_hazard(state, &NOPs, 4, op); } } handle_smem_clause_hazards(state.program, ctx, instr, &NOPs); } else if (instr->isSALU()) { if (instr->opcode == aco_opcode::s_setreg_b32 || instr->opcode == aco_opcode::s_setreg_imm32_b32 || instr->opcode == aco_opcode::s_getreg_b32) { NOPs = MAX2(NOPs, ctx.setreg_then_getsetreg); } if (state.program->gfx_level == GFX9) { if (instr->opcode == aco_opcode::s_movrels_b32 || instr->opcode == aco_opcode::s_movrels_b64 || instr->opcode == aco_opcode::s_movreld_b32 || instr->opcode == aco_opcode::s_movreld_b64) { NOPs = MAX2(NOPs, ctx.salu_wr_m0_then_moverel); } } if (instr->opcode == aco_opcode::s_sendmsg || instr->opcode == aco_opcode::s_ttracedata) NOPs = MAX2(NOPs, ctx.salu_wr_m0_then_gds_msg_ttrace); } else if (instr->isDS() && instr->ds().gds) { NOPs = MAX2(NOPs, ctx.salu_wr_m0_then_gds_msg_ttrace); } else if (instr->isVALU() || instr->isVINTRP()) { if (instr->isDPP()) { NOPs = MAX2(NOPs, ctx.valu_wr_exec_then_dpp); handle_valu_then_read_hazard(state, &NOPs, 2, instr->operands[0]); } for (Definition def : instr->definitions) { if (def.regClass().type() != RegType::sgpr) { for (unsigned i = 0; i < def.size(); i++) NOPs = MAX2(NOPs, ctx.vmem_store_then_wr_data[(def.physReg() & 0xff) + i]); } } if ((instr->opcode == aco_opcode::v_readlane_b32 || instr->opcode == aco_opcode::v_readlane_b32_e64 || instr->opcode == aco_opcode::v_writelane_b32 || instr->opcode == aco_opcode::v_writelane_b32_e64) && !instr->operands[1].isConstant()) { handle_valu_then_read_hazard(state, &NOPs, 4, instr->operands[1]); } /* It's required to insert 1 wait state if the dst VGPR of any v_interp_* * is followed by a read with v_readfirstlane or v_readlane to fix GPU * hangs on GFX6. Note that v_writelane_* is apparently not affected. * This hazard isn't documented anywhere but AMD confirmed that hazard. */ if (state.program->gfx_level == GFX6 && (instr->opcode == aco_opcode::v_readlane_b32 || /* GFX6 doesn't have v_readlane_b32_e64 */ instr->opcode == aco_opcode::v_readfirstlane_b32)) { handle_vintrp_then_read_hazard(state, &NOPs, 1, instr->operands[0]); } if (instr->opcode == aco_opcode::v_div_fmas_f32 || instr->opcode == aco_opcode::v_div_fmas_f64) NOPs = MAX2(NOPs, ctx.valu_wr_vcc_then_div_fmas); } else if (instr->isVMEM() || instr->isFlatLike()) { /* If the VALU writes the SGPR that is used by a VMEM, the user must add five wait states. */ for (Operand op : instr->operands) { if (!op.isConstant() && !op.isUndefined() && op.regClass().type() == RegType::sgpr) handle_valu_then_read_hazard(state, &NOPs, 5, op); } } if (!instr->isSALU() && instr->format != Format::SMEM) NOPs = MAX2(NOPs, ctx.set_vskip_mode_then_vector); if (state.program->gfx_level == GFX9) { bool lds_scratch_global = (instr->isScratch() || instr->isGlobal()) && instr->flatlike().lds; if (instr->isVINTRP() || lds_scratch_global || instr->opcode == aco_opcode::ds_read_addtid_b32 || instr->opcode == aco_opcode::ds_write_addtid_b32 || instr->opcode == aco_opcode::buffer_store_lds_dword) { NOPs = MAX2(NOPs, ctx.salu_wr_m0_then_lds); } } ctx.add_wait_states(NOPs + get_wait_states(instr)); // TODO: try to schedule the NOP-causing instruction up to reduce the number of stall cycles if (NOPs) { /* create NOP */ aco_ptr nop{create_instruction(aco_opcode::s_nop, Format::SOPP, 0, 0)}; nop->salu().imm = NOPs - 1; new_instructions.emplace_back(std::move(nop)); } /* update information to check for later hazards */ if ((ctx.smem_clause || ctx.smem_write) && (NOPs || instr->format != Format::SMEM)) { ctx.smem_clause = false; ctx.smem_write = false; if (state.program->dev.xnack_enabled) { BITSET_ZERO(ctx.smem_clause_read_write); BITSET_ZERO(ctx.smem_clause_write); } } if (instr->isSMEM()) { if (instr->definitions.empty() || instr_info.is_atomic[(unsigned)instr->opcode]) { ctx.smem_write = true; } else { ctx.smem_clause = true; if (state.program->dev.xnack_enabled) { for (Operand op : instr->operands) { if (!op.isConstant()) { set_bitset_range(ctx.smem_clause_read_write, op.physReg(), op.size()); } } Definition def = instr->definitions[0]; set_bitset_range(ctx.smem_clause_read_write, def.physReg(), def.size()); set_bitset_range(ctx.smem_clause_write, def.physReg(), def.size()); } } } else if (instr->isVALU()) { for (Definition def : instr->definitions) { if (def.regClass().type() == RegType::sgpr) { if (def.physReg() == vcc || def.physReg() == vcc_hi) { ctx.valu_wr_vcc_then_div_fmas = 4; } if (def.physReg() == exec || def.physReg() == exec_hi) { ctx.valu_wr_exec_then_dpp = 5; } } } } else if (instr->isSALU()) { if (!instr->definitions.empty()) { /* all other definitions should be SCC */ Definition def = instr->definitions[0]; if (def.physReg() == m0) { ctx.salu_wr_m0_then_gds_msg_ttrace = 1; ctx.salu_wr_m0_then_lds = 1; ctx.salu_wr_m0_then_moverel = 1; } } else if (instr->opcode == aco_opcode::s_setreg_b32 || instr->opcode == aco_opcode::s_setreg_imm32_b32) { SALU_instruction& sopk = instr->salu(); unsigned offset = (sopk.imm >> 6) & 0x1f; unsigned size = ((sopk.imm >> 11) & 0x1f) + 1; unsigned reg = sopk.imm & 0x3f; ctx.setreg_then_getsetreg = 2; if (reg == 1 && offset >= 28 && size > (28 - offset)) ctx.set_vskip_mode_then_vector = 2; } } else if (instr->isVMEM() || instr->isFlatLike()) { /* >64-bit MUBUF/MTBUF store with a constant in SOFFSET */ bool consider_buf = (instr->isMUBUF() || instr->isMTBUF()) && instr->operands.size() == 4 && instr->operands[3].size() > 2 && instr->operands[2].physReg() >= 128; /* MIMG store with a 128-bit T# with more than two bits set in dmask (making it a >64-bit * store) */ bool consider_mimg = instr->isMIMG() && instr->operands[1].regClass().type() == RegType::vgpr && instr->operands[1].size() > 2 && instr->operands[0].size() == 4; /* FLAT/GLOBAL/SCRATCH store with >64-bit data */ bool consider_flat = instr->isFlatLike() && instr->operands.size() == 3 && instr->operands[2].size() > 2; if (consider_buf || consider_mimg || consider_flat) { PhysReg wrdata = instr->operands[consider_flat ? 2 : 3].physReg(); unsigned size = instr->operands[consider_flat ? 2 : 3].size(); for (unsigned i = 0; i < size; i++) ctx.vmem_store_then_wr_data[(wrdata & 0xff) + i] = 1; } } } bool is_latest_instr_vintrp(bool& global_state, bool& block_state, aco_ptr& pred) { if (pred->isVINTRP()) global_state = true; return true; } template bool handle_wr_hazard_instr(int& global_state, int& block_state, aco_ptr& pred) { if (Salu ? pred->isSALU() : (pred->isVALU() || pred->isVINTRP())) { for (Definition dst : pred->definitions) { if ((dst.physReg().reg() < 256) == Sgpr) { global_state = MAX2(global_state, block_state); return true; } } } block_state -= get_wait_states(pred); return block_state <= 0; } template void handle_wr_hazard(State& state, int* NOPs, int min_states) { if (*NOPs >= min_states) return; int global = 0; int block = min_states; search_backwards>(state, global, block); *NOPs = MAX2(*NOPs, global); } void resolve_all_gfx6(State& state, NOP_ctx_gfx6& ctx, std::vector>& new_instructions) { int NOPs = 0; /* SGPR->SMEM hazards */ if (state.program->gfx_level == GFX6) { handle_wr_hazard(state, &NOPs, 4); handle_wr_hazard(state, &NOPs, 4); } /* Break up SMEM clauses */ if (ctx.smem_clause || ctx.smem_write) NOPs = MAX2(NOPs, 1); /* SALU/GDS hazards */ NOPs = MAX2(NOPs, ctx.setreg_then_getsetreg); if (state.program->gfx_level == GFX9) NOPs = MAX2(NOPs, ctx.salu_wr_m0_then_moverel); NOPs = MAX2(NOPs, ctx.salu_wr_m0_then_gds_msg_ttrace); /* VALU hazards */ NOPs = MAX2(NOPs, ctx.valu_wr_exec_then_dpp); if (state.program->gfx_level >= GFX8) handle_wr_hazard(state, &NOPs, 2); /* VALU->DPP */ NOPs = MAX2(NOPs, ctx.vmem_store_then_wr_data.any() ? 1 : 0); if (state.program->gfx_level == GFX6) { /* VINTRP->v_readlane_b32/etc */ bool vintrp = false; search_backwards(state, vintrp, vintrp); if (vintrp) NOPs = MAX2(NOPs, 1); } NOPs = MAX2(NOPs, ctx.valu_wr_vcc_then_div_fmas); /* VALU(sgpr)->VMEM/v_readlane_b32/etc hazards. v_readlane_b32/etc require only 4 NOPs. */ handle_wr_hazard(state, &NOPs, 5); NOPs = MAX2(NOPs, ctx.set_vskip_mode_then_vector); if (state.program->gfx_level == GFX9) NOPs = MAX2(NOPs, ctx.salu_wr_m0_then_lds); ctx.add_wait_states(NOPs); if (NOPs) { Builder bld(state.program, &new_instructions); bld.sopp(aco_opcode::s_nop, NOPs - 1); } } template bool check_written_regs(const aco_ptr& instr, const std::bitset& check_regs) { return std::any_of(instr->definitions.begin(), instr->definitions.end(), [&check_regs](const Definition& def) -> bool { bool writes_any = false; for (unsigned i = 0; i < def.size(); i++) { unsigned def_reg = def.physReg() + i; writes_any |= def_reg < check_regs.size() && check_regs[def_reg]; } return writes_any; }); } template bool check_read_regs(const aco_ptr& instr, const std::bitset& check_regs) { return std::any_of(instr->operands.begin(), instr->operands.end(), [&check_regs](const Operand& op) -> bool { if (op.isConstant()) return false; bool writes_any = false; for (unsigned i = 0; i < op.size(); i++) { unsigned op_reg = op.physReg() + i; writes_any |= op_reg < check_regs.size() && check_regs[op_reg]; } return writes_any; }); } template void mark_read_regs(const aco_ptr& instr, std::bitset& reg_reads) { for (const Operand& op : instr->operands) { for (unsigned i = 0; i < op.size(); i++) { unsigned reg = op.physReg() + i; if (reg < reg_reads.size()) reg_reads.set(reg); } } } template void mark_read_regs_exec(State& state, const aco_ptr& instr, std::bitset& reg_reads) { mark_read_regs(instr, reg_reads); reg_reads.set(exec); if (state.program->wave_size == 64) reg_reads.set(exec_hi); } bool VALU_writes_sgpr(aco_ptr& instr) { if (instr->isVOPC()) return true; if (instr->isVOP3() && instr->definitions.size() == 2) return true; if (instr->opcode == aco_opcode::v_readfirstlane_b32 || instr->opcode == aco_opcode::v_readlane_b32 || instr->opcode == aco_opcode::v_readlane_b32_e64) return true; return false; } bool instr_writes_sgpr(const aco_ptr& instr) { return std::any_of(instr->definitions.begin(), instr->definitions.end(), [](const Definition& def) -> bool { return def.getTemp().type() == RegType::sgpr; }); } inline bool instr_is_branch(const aco_ptr& instr) { return instr->opcode == aco_opcode::s_branch || instr->opcode == aco_opcode::s_cbranch_scc0 || instr->opcode == aco_opcode::s_cbranch_scc1 || instr->opcode == aco_opcode::s_cbranch_vccz || instr->opcode == aco_opcode::s_cbranch_vccnz || instr->opcode == aco_opcode::s_cbranch_execz || instr->opcode == aco_opcode::s_cbranch_execnz || instr->opcode == aco_opcode::s_cbranch_cdbgsys || instr->opcode == aco_opcode::s_cbranch_cdbguser || instr->opcode == aco_opcode::s_cbranch_cdbgsys_or_user || instr->opcode == aco_opcode::s_cbranch_cdbgsys_and_user || instr->opcode == aco_opcode::s_subvector_loop_begin || instr->opcode == aco_opcode::s_subvector_loop_end || instr->opcode == aco_opcode::s_setpc_b64 || instr->opcode == aco_opcode::s_swappc_b64 || instr->opcode == aco_opcode::s_getpc_b64 || instr->opcode == aco_opcode::s_call_b64; } void handle_instruction_gfx10(State& state, NOP_ctx_gfx10& ctx, aco_ptr& instr, std::vector>& new_instructions) { // TODO: s_dcache_inv needs to be in it's own group on GFX10 Builder bld(state.program, &new_instructions); unsigned vm_vsrc = 7; unsigned sa_sdst = 1; if (debug_flags & DEBUG_FORCE_WAITDEPS) { bld.sopp(aco_opcode::s_waitcnt_depctr, 0x0000); vm_vsrc = 0; sa_sdst = 0; } else if (instr->opcode == aco_opcode::s_waitcnt_depctr) { vm_vsrc = (instr->salu().imm >> 2) & 0x7; sa_sdst = instr->salu().imm & 0x1; } /* VMEMtoScalarWriteHazard * Handle EXEC/M0/SGPR write following a VMEM/DS instruction without a VALU or "waitcnt vmcnt(0)" * in-between. */ if (instr->isVMEM() || instr->isFlatLike() || instr->isDS()) { /* Remember all SGPRs that are read by the VMEM/DS instruction */ if (instr->isVMEM() || instr->isFlatLike()) mark_read_regs_exec( state, instr, instr->definitions.empty() ? ctx.sgprs_read_by_VMEM_store : ctx.sgprs_read_by_VMEM); if (instr->isFlat() || instr->isDS()) mark_read_regs_exec(state, instr, ctx.sgprs_read_by_DS); } else if (instr->isSALU() || instr->isSMEM()) { wait_imm imm; if (imm.unpack(state.program->gfx_level, instr.get())) { if (imm.vm == 0) ctx.sgprs_read_by_VMEM.reset(); if (imm.lgkm == 0) ctx.sgprs_read_by_DS.reset(); if (imm.vs == 0) ctx.sgprs_read_by_VMEM_store.reset(); } else if (vm_vsrc == 0) { ctx.sgprs_read_by_VMEM.reset(); ctx.sgprs_read_by_DS.reset(); ctx.sgprs_read_by_VMEM_store.reset(); } /* Check if SALU writes an SGPR that was previously read by the VALU */ if (check_written_regs(instr, ctx.sgprs_read_by_VMEM) || check_written_regs(instr, ctx.sgprs_read_by_DS) || check_written_regs(instr, ctx.sgprs_read_by_VMEM_store)) { ctx.sgprs_read_by_VMEM.reset(); ctx.sgprs_read_by_DS.reset(); ctx.sgprs_read_by_VMEM_store.reset(); /* Insert s_waitcnt_depctr instruction with magic imm to mitigate the problem */ bld.sopp(aco_opcode::s_waitcnt_depctr, 0xffe3); } } else if (instr->isVALU()) { /* Hazard is mitigated by any VALU instruction */ ctx.sgprs_read_by_VMEM.reset(); ctx.sgprs_read_by_DS.reset(); ctx.sgprs_read_by_VMEM_store.reset(); } /* VcmpxPermlaneHazard * Handle any permlane following a VOPC instruction writing exec, insert v_mov between them. */ if (instr->isVOPC() && instr->definitions[0].physReg() == exec) { /* we only need to check definitions[0] because since GFX10 v_cmpx only writes one dest */ ctx.has_VOPC_write_exec = true; } else if (ctx.has_VOPC_write_exec && (instr->opcode == aco_opcode::v_permlane16_b32 || instr->opcode == aco_opcode::v_permlanex16_b32)) { ctx.has_VOPC_write_exec = false; /* v_nop would be discarded by SQ, so use v_mov with the first operand of the permlane */ bld.vop1(aco_opcode::v_mov_b32, Definition(instr->operands[0].physReg(), v1), Operand(instr->operands[0].physReg(), v1)); } else if (instr->isVALU() && instr->opcode != aco_opcode::v_nop) { ctx.has_VOPC_write_exec = false; } /* VcmpxExecWARHazard * Handle any VALU instruction writing the exec mask after it was read by a non-VALU instruction. */ if (!instr->isVALU() && instr->reads_exec()) { ctx.has_nonVALU_exec_read = true; } else if (instr->isVALU() && ctx.has_nonVALU_exec_read) { if (instr->writes_exec()) { ctx.has_nonVALU_exec_read = false; /* Insert s_waitcnt_depctr instruction with magic imm to mitigate the problem */ bld.sopp(aco_opcode::s_waitcnt_depctr, 0xfffe); } else if (instr_writes_sgpr(instr)) { /* Any VALU instruction that writes an SGPR mitigates the problem */ ctx.has_nonVALU_exec_read = false; } } else if (sa_sdst == 0) { ctx.has_nonVALU_exec_read = false; } /* SMEMtoVectorWriteHazard * Handle any VALU instruction writing an SGPR after an SMEM reads it. */ if (instr->isSMEM()) { /* Remember all SGPRs that are read by the SMEM instruction */ mark_read_regs(instr, ctx.sgprs_read_by_SMEM); } else if (VALU_writes_sgpr(instr)) { /* Check if VALU writes an SGPR that was previously read by SMEM */ if (check_written_regs(instr, ctx.sgprs_read_by_SMEM)) { ctx.sgprs_read_by_SMEM.reset(); /* Insert s_mov to mitigate the problem */ bld.sop1(aco_opcode::s_mov_b32, Definition(sgpr_null, s1), Operand::zero()); } } else if (instr->isSALU()) { wait_imm imm; if (imm.unpack(state.program->gfx_level, instr.get()) && imm.lgkm == 0) { /* Reducing lgkmcnt count to 0 always mitigates the hazard. */ ctx.sgprs_read_by_SMEM.reset(); } else if (instr->format != Format::SOPP && instr->definitions.size()) { /* SALU can mitigate the hazard */ ctx.sgprs_read_by_SMEM.reset(); } } /* LdsBranchVmemWARHazard * Handle VMEM/GLOBAL/SCRATCH->branch->DS and DS->branch->VMEM/GLOBAL/SCRATCH patterns. */ if (instr->isVMEM() || instr->isGlobal() || instr->isScratch()) { if (ctx.has_branch_after_DS) bld.sopk(aco_opcode::s_waitcnt_vscnt, Operand(sgpr_null, s1), 0); ctx.has_branch_after_VMEM = ctx.has_branch_after_DS = ctx.has_DS = false; ctx.has_VMEM = true; } else if (instr->isDS()) { if (ctx.has_branch_after_VMEM) bld.sopk(aco_opcode::s_waitcnt_vscnt, Operand(sgpr_null, s1), 0); ctx.has_branch_after_VMEM = ctx.has_branch_after_DS = ctx.has_VMEM = false; ctx.has_DS = true; } else if (instr_is_branch(instr)) { ctx.has_branch_after_VMEM |= ctx.has_VMEM; ctx.has_branch_after_DS |= ctx.has_DS; ctx.has_VMEM = ctx.has_DS = false; } else if (instr->opcode == aco_opcode::s_waitcnt_vscnt) { /* Only s_waitcnt_vscnt can mitigate the hazard */ const SALU_instruction& sopk = instr->salu(); if (sopk.operands[0].physReg() == sgpr_null && sopk.imm == 0) ctx.has_VMEM = ctx.has_branch_after_VMEM = ctx.has_DS = ctx.has_branch_after_DS = false; } /* NSAToVMEMBug * Handles NSA MIMG (4 or more dwords) immediately followed by MUBUF/MTBUF (with offset[2:1] != * 0). */ if (instr->isMIMG() && get_mimg_nsa_dwords(instr.get()) > 1) { ctx.has_NSA_MIMG = true; } else if (ctx.has_NSA_MIMG) { ctx.has_NSA_MIMG = false; if (instr->isMUBUF() || instr->isMTBUF()) { uint32_t offset = instr->isMUBUF() ? instr->mubuf().offset : instr->mtbuf().offset; if (offset & 6) bld.sopp(aco_opcode::s_nop, 0); } } /* waNsaCannotFollowWritelane * Handles NSA MIMG immediately following a v_writelane_b32. */ if (instr->opcode == aco_opcode::v_writelane_b32_e64) { ctx.has_writelane = true; } else if (ctx.has_writelane) { ctx.has_writelane = false; if (instr->isMIMG() && get_mimg_nsa_dwords(instr.get()) > 0) bld.sopp(aco_opcode::s_nop, 0); } } void resolve_all_gfx10(State& state, NOP_ctx_gfx10& ctx, std::vector>& new_instructions) { Builder bld(state.program, &new_instructions); size_t prev_count = new_instructions.size(); /* VcmpxPermlaneHazard */ if (ctx.has_VOPC_write_exec) { ctx.has_VOPC_write_exec = false; bld.vop1(aco_opcode::v_mov_b32, Definition(PhysReg(256), v1), Operand(PhysReg(256), v1)); /* VALU mitigates VMEMtoScalarWriteHazard. */ ctx.sgprs_read_by_VMEM.reset(); ctx.sgprs_read_by_DS.reset(); ctx.sgprs_read_by_VMEM_store.reset(); } unsigned waitcnt_depctr = 0xffff; /* VMEMtoScalarWriteHazard */ if (ctx.sgprs_read_by_VMEM.any() || ctx.sgprs_read_by_DS.any() || ctx.sgprs_read_by_VMEM_store.any()) { ctx.sgprs_read_by_VMEM.reset(); ctx.sgprs_read_by_DS.reset(); ctx.sgprs_read_by_VMEM_store.reset(); waitcnt_depctr &= 0xffe3; } /* VcmpxExecWARHazard */ if (ctx.has_nonVALU_exec_read) { ctx.has_nonVALU_exec_read = false; waitcnt_depctr &= 0xfffe; } if (waitcnt_depctr != 0xffff) bld.sopp(aco_opcode::s_waitcnt_depctr, waitcnt_depctr); /* SMEMtoVectorWriteHazard */ if (ctx.sgprs_read_by_SMEM.any()) { ctx.sgprs_read_by_SMEM.reset(); bld.sop1(aco_opcode::s_mov_b32, Definition(sgpr_null, s1), Operand::zero()); } /* LdsBranchVmemWARHazard */ if (ctx.has_VMEM || ctx.has_branch_after_VMEM || ctx.has_DS || ctx.has_branch_after_DS) { bld.sopk(aco_opcode::s_waitcnt_vscnt, Operand(sgpr_null, s1), 0); ctx.has_VMEM = ctx.has_branch_after_VMEM = ctx.has_DS = ctx.has_branch_after_DS = false; } /* NSAToVMEMBug/waNsaCannotFollowWritelane */ if (ctx.has_NSA_MIMG || ctx.has_writelane) { ctx.has_NSA_MIMG = ctx.has_writelane = false; /* Any instruction resolves these hazards. */ if (new_instructions.size() == prev_count) bld.sopp(aco_opcode::s_nop, 0); } } void fill_vgpr_bitset(std::bitset<256>& set, PhysReg reg, unsigned bytes) { if (reg.reg() < 256) return; for (unsigned i = 0; i < DIV_ROUND_UP(bytes, 4); i++) set.set(reg.reg() - 256 + i); } bool test_vgpr_bitset(std::bitset<256>& set, Operand op) { if (op.physReg().reg() < 256) return false; for (unsigned i = 0; i < op.size(); i++) { if (set[op.physReg().reg() - 256 + i]) return true; } return false; } /* GFX11 */ struct LdsDirectVALUHazardGlobalState { unsigned wait_vdst = 15; PhysReg vgpr; std::set loop_headers_visited; }; struct LdsDirectVALUHazardBlockState { unsigned num_valu = 0; bool has_trans = false; unsigned num_instrs = 0; unsigned num_blocks = 0; }; bool handle_lds_direct_valu_hazard_instr(LdsDirectVALUHazardGlobalState& global_state, LdsDirectVALUHazardBlockState& block_state, aco_ptr& instr) { if (instr->isVALU()) { block_state.has_trans |= instr->isTrans(); bool uses_vgpr = false; for (Definition& def : instr->definitions) uses_vgpr |= regs_intersect(def.physReg(), def.size(), global_state.vgpr, 1); for (Operand& op : instr->operands) { uses_vgpr |= !op.isConstant() && regs_intersect(op.physReg(), op.size(), global_state.vgpr, 1); } if (uses_vgpr) { /* Transcendentals execute in parallel to other VALU and va_vdst count becomes unusable */ global_state.wait_vdst = MIN2(global_state.wait_vdst, block_state.has_trans ? 0 : block_state.num_valu); return true; } block_state.num_valu++; } if (parse_depctr_wait(instr.get()).va_vdst == 0) return true; block_state.num_instrs++; if (block_state.num_instrs > 256 || block_state.num_blocks > 32) { /* Exit to limit compile times and set wait_vdst to be safe. */ global_state.wait_vdst = MIN2(global_state.wait_vdst, block_state.has_trans ? 0 : block_state.num_valu); return true; } return block_state.num_valu >= global_state.wait_vdst; } bool handle_lds_direct_valu_hazard_block(LdsDirectVALUHazardGlobalState& global_state, LdsDirectVALUHazardBlockState& block_state, Block* block) { if (block->kind & block_kind_loop_header) { if (global_state.loop_headers_visited.count(block->index)) return false; global_state.loop_headers_visited.insert(block->index); } block_state.num_blocks++; return true; } unsigned handle_lds_direct_valu_hazard(State& state, aco_ptr& instr) { /* LdsDirectVALUHazard * Handle LDSDIR writing a VGPR after it's used by a VALU instruction. */ if (instr->ldsdir().wait_vdst == 0) return 0; /* early exit */ LdsDirectVALUHazardGlobalState global_state; global_state.wait_vdst = instr->ldsdir().wait_vdst; global_state.vgpr = instr->definitions[0].physReg(); LdsDirectVALUHazardBlockState block_state; search_backwards( state, global_state, block_state); return global_state.wait_vdst; } enum VALUPartialForwardingHazardState : uint8_t { nothing_written, written_after_exec_write, exec_written, }; struct VALUPartialForwardingHazardGlobalState { bool hazard_found = false; std::set loop_headers_visited; }; struct VALUPartialForwardingHazardBlockState { /* initialized by number of VGPRs read by VALU, decrement when encountered to return early */ uint8_t num_vgprs_read = 0; BITSET_DECLARE(vgprs_read, 256) = {0}; enum VALUPartialForwardingHazardState state = nothing_written; unsigned num_valu_since_read = 0; unsigned num_valu_since_write = 0; unsigned num_instrs = 0; unsigned num_blocks = 0; }; bool handle_valu_partial_forwarding_hazard_instr(VALUPartialForwardingHazardGlobalState& global_state, VALUPartialForwardingHazardBlockState& block_state, aco_ptr& instr) { /* Check if there is already a hazard found on some other control flow path. */ if (global_state.hazard_found) return true; if (instr->isSALU() && !instr->definitions.empty()) { if (block_state.state == written_after_exec_write && instr->writes_exec()) block_state.state = exec_written; } else if (instr->isVALU()) { bool vgpr_write = false; for (Definition& def : instr->definitions) { if (def.physReg().reg() < 256) continue; for (unsigned i = 0; i < def.size(); i++) { unsigned reg = def.physReg().reg() - 256 + i; if (!BITSET_TEST(block_state.vgprs_read, reg)) continue; if (block_state.state == exec_written && block_state.num_valu_since_write < 3) { global_state.hazard_found = true; return true; } BITSET_CLEAR(block_state.vgprs_read, reg); block_state.num_vgprs_read--; vgpr_write = true; } } if (vgpr_write) { /* If the state is nothing_written: the check below should ensure that this write is * close enough to the read. * * If the state is exec_written: the current choice of second write has failed. Reset and * try with the current write as the second one, if it's close enough to the read. * * If the state is written_after_exec_write: a further second write would be better, if * it's close enough to the read. */ if (block_state.state == nothing_written || block_state.num_valu_since_read < 5) { block_state.state = written_after_exec_write; block_state.num_valu_since_write = 0; } else { block_state.num_valu_since_write++; } } else { block_state.num_valu_since_write++; } block_state.num_valu_since_read++; } else if (parse_depctr_wait(instr.get()).va_vdst == 0) { return true; } if (block_state.num_valu_since_read >= (block_state.state == nothing_written ? 5 : 8)) return true; /* Hazard not possible at this distance. */ if (block_state.num_vgprs_read == 0) return true; /* All VGPRs have been written and a hazard was never found. */ block_state.num_instrs++; if (block_state.num_instrs > 256 || block_state.num_blocks > 32) { /* Exit to limit compile times and set hazard_found=true to be safe. */ global_state.hazard_found = true; return true; } return false; } bool handle_valu_partial_forwarding_hazard_block(VALUPartialForwardingHazardGlobalState& global_state, VALUPartialForwardingHazardBlockState& block_state, Block* block) { if (block->kind & block_kind_loop_header) { if (global_state.loop_headers_visited.count(block->index)) return false; global_state.loop_headers_visited.insert(block->index); } block_state.num_blocks++; return true; } bool handle_valu_partial_forwarding_hazard(State& state, aco_ptr& instr) { /* VALUPartialForwardingHazard * VALU instruction reads two VGPRs: one written before an exec write by SALU and one after. * For the hazard, there must be less than 3 VALU between the first and second VGPR writes. * There also must be less than 5 VALU between the second VGPR write and the current instruction. */ if (state.program->wave_size != 64 || !instr->isVALU()) return false; unsigned num_vgprs = 0; for (Operand& op : instr->operands) num_vgprs += op.physReg().reg() < 256 ? op.size() : 1; if (num_vgprs <= 1) return false; /* early exit */ VALUPartialForwardingHazardBlockState block_state; for (unsigned i = 0; i < instr->operands.size(); i++) { Operand& op = instr->operands[i]; if (op.physReg().reg() < 256) continue; for (unsigned j = 0; j < op.size(); j++) BITSET_SET(block_state.vgprs_read, op.physReg().reg() - 256 + j); } block_state.num_vgprs_read = BITSET_COUNT(block_state.vgprs_read); if (block_state.num_vgprs_read <= 1) return false; /* early exit */ VALUPartialForwardingHazardGlobalState global_state; search_backwards(state, global_state, block_state); return global_state.hazard_found; } void handle_instruction_gfx11(State& state, NOP_ctx_gfx11& ctx, aco_ptr& instr, std::vector>& new_instructions) { Builder bld(state.program, &new_instructions); /* Due to a hazard, an s_nop is needed before "s_sendmsg sendmsg_dealloc_vgprs". */ if (instr->opcode == aco_opcode::s_sendmsg && instr->salu().imm == sendmsg_dealloc_vgprs && (new_instructions.empty() || new_instructions.back()->opcode != aco_opcode::s_nop)) { bld.sopp(aco_opcode::s_nop, 0); } /* VcmpxPermlaneHazard * Handle any permlane following a VOPC instruction writing exec, insert v_mov between them. */ if (instr->isVOPC() && instr->definitions[0].physReg() == exec) { ctx.has_Vcmpx = true; } else if (ctx.has_Vcmpx && (instr->opcode == aco_opcode::v_permlane16_b32 || instr->opcode == aco_opcode::v_permlanex16_b32 || instr->opcode == aco_opcode::v_permlane64_b32 || instr->opcode == aco_opcode::v_permlane16_var_b32 || instr->opcode == aco_opcode::v_permlanex16_var_b32)) { ctx.has_Vcmpx = false; /* Unlike on GFX10, v_nop should resolve the hazard on GFX11. */ bld.vop1(aco_opcode::v_nop); } else if (instr->isVALU()) { ctx.has_Vcmpx = false; } unsigned va_vdst = parse_depctr_wait(instr.get()).va_vdst; unsigned vm_vsrc = 7; unsigned sa_sdst = 1; if (debug_flags & DEBUG_FORCE_WAITDEPS) { bld.sopp(aco_opcode::s_waitcnt_depctr, 0x0000); va_vdst = 0; vm_vsrc = 0; sa_sdst = 0; } else if (instr->opcode == aco_opcode::s_waitcnt_depctr) { /* va_vdst already obtained through parse_depctr_wait(). */ vm_vsrc = (instr->salu().imm >> 2) & 0x7; sa_sdst = instr->salu().imm & 0x1; } else if (instr->isLDSDIR() && state.program->gfx_level >= GFX12) { vm_vsrc = instr->ldsdir().wait_vsrc ? 7 : 0; } if (instr->isLDSDIR()) { unsigned count = handle_lds_direct_valu_hazard(state, instr); LDSDIR_instruction* ldsdir = &instr->ldsdir(); if (count < va_vdst) { ldsdir->wait_vdst = MIN2(ldsdir->wait_vdst, count); va_vdst = MIN2(va_vdst, count); } } /* VALUTransUseHazard * VALU reads VGPR written by transcendental instruction without 6+ VALU or 2+ transcendental * in-between. */ if (state.program->gfx_level < GFX11_5 && va_vdst > 0 && instr->isVALU()) { uint8_t num_valu = 15; uint8_t num_trans = 15; for (Operand& op : instr->operands) { if (op.physReg().reg() < 256) continue; for (unsigned i = 0; i < op.size(); i++) { PhysReg reg = op.physReg().advance(i * 4); num_valu = std::min(num_valu, ctx.valu_since_wr_by_trans.get(reg)); num_trans = std::min(num_trans, ctx.trans_since_wr_by_trans.get(reg)); } } if (num_trans <= 1 && num_valu <= 5) { bld.sopp(aco_opcode::s_waitcnt_depctr, 0x0fff); va_vdst = 0; } } if (va_vdst > 0 && state.program->gfx_level < GFX12 && handle_valu_partial_forwarding_hazard(state, instr)) { bld.sopp(aco_opcode::s_waitcnt_depctr, 0x0fff); va_vdst = 0; } if (state.program->gfx_level < GFX12) { /* VALUMaskWriteHazard * VALU reads SGPR as a lane mask and later written by SALU cannot safely be read by SALU or * VALU. */ if (state.program->wave_size == 64 && (instr->isSALU() || instr->isVALU()) && check_read_regs(instr, ctx.sgpr_read_by_valu_as_lanemask_then_wr_by_salu)) { bld.sopp(aco_opcode::s_waitcnt_depctr, 0xfffe); sa_sdst = 0; } if (va_vdst == 0) { ctx.valu_since_wr_by_trans.reset(); ctx.trans_since_wr_by_trans.reset(); } if (sa_sdst == 0) ctx.sgpr_read_by_valu_as_lanemask_then_wr_by_salu.reset(); if (state.program->wave_size == 64 && instr->isSALU() && check_written_regs(instr, ctx.sgpr_read_by_valu_as_lanemask)) { unsigned reg = instr->definitions[0].physReg().reg(); for (unsigned i = 0; i < instr->definitions[0].size(); i++) ctx.sgpr_read_by_valu_as_lanemask_then_wr_by_salu[reg + i] = 1; } if (instr->isVALU()) { bool is_trans = instr->isTrans(); ctx.valu_since_wr_by_trans.inc(); if (is_trans) ctx.trans_since_wr_by_trans.inc(); if (is_trans) { for (Definition& def : instr->definitions) { for (unsigned i = 0; i < def.size(); i++) { PhysReg reg = def.physReg().advance(i * 4); ctx.valu_since_wr_by_trans.set(reg); ctx.trans_since_wr_by_trans.set(reg); } } } if (state.program->wave_size == 64) { for (Operand& op : instr->operands) { /* This should ignore exec reads */ if (!op.isConstant() && op.physReg().reg() < 126) ctx.sgpr_read_by_valu_as_lanemask.reset(); } switch (instr->opcode) { case aco_opcode::v_addc_co_u32: case aco_opcode::v_subb_co_u32: case aco_opcode::v_subbrev_co_u32: case aco_opcode::v_cndmask_b16: case aco_opcode::v_cndmask_b32: case aco_opcode::v_div_fmas_f32: case aco_opcode::v_div_fmas_f64: if (instr->operands.back().physReg() != exec) { ctx.sgpr_read_by_valu_as_lanemask.set(instr->operands.back().physReg().reg()); ctx.sgpr_read_by_valu_as_lanemask.set(instr->operands.back().physReg().reg() + 1); } break; default: break; } } } } else { /* VALUReadSGPRHazard * VALU reads SGPR and later written by SALU cannot safely be read by VALU/SALU. */ if (instr->isVALU() || instr->isSALU()) { unsigned expiry_count = instr->isSALU() ? 10 : 11; for (Operand& op : instr->operands) { if (sa_sdst == 0) break; for (unsigned i = 0; i < op.size(); i++) { PhysReg reg = op.physReg().advance(i * 4); if (reg <= m0 && ctx.sgpr_read_by_valu_then_wr_by_salu.get(reg) < expiry_count) { bld.sopp(aco_opcode::s_waitcnt_depctr, 0xfffe); sa_sdst = 0; break; } } } } if (sa_sdst == 0) ctx.sgpr_read_by_valu_then_wr_by_salu.reset(); else if (instr->isSALU() && !instr->isSOPP()) ctx.sgpr_read_by_valu_then_wr_by_salu.inc(); if (instr->isVALU()) { for (const Operand& op : instr->operands) { for (unsigned i = 0; i < DIV_ROUND_UP(op.size(), 2); i++) { unsigned reg = (op.physReg() / 2) + i; if (reg < ctx.sgpr_read_by_valu.size()) ctx.sgpr_read_by_valu.set(reg); } } } else if (instr->isSALU() && !instr->definitions.empty()) { for (unsigned i = 0; i < instr->definitions[0].size(); i++) { PhysReg def_reg = instr->definitions[0].physReg().advance(i * 4); if ((def_reg / 2) < ctx.sgpr_read_by_valu.size() && ctx.sgpr_read_by_valu[def_reg / 2]) ctx.sgpr_read_by_valu_then_wr_by_salu.set(def_reg); } } } /* LdsDirectVMEMHazard * Handle LDSDIR writing a VGPR after it's used by a VMEM/DS instruction. */ if (instr->isVMEM() || instr->isFlatLike()) { if (instr->definitions.empty()) { for (Operand& op : instr->operands) fill_vgpr_bitset(ctx.vgpr_used_by_vmem_store, op.physReg(), op.bytes()); } else { uint8_t vmem_type = state.program->gfx_level >= GFX12 ? get_vmem_type(state.program->gfx_level, instr.get()) : vmem_nosampler; std::bitset<256>* vgprs = &ctx.vgpr_used_by_vmem_load; if (vmem_type == vmem_sampler) vgprs = &ctx.vgpr_used_by_vmem_sample; else if (vmem_type == vmem_bvh) vgprs = &ctx.vgpr_used_by_vmem_bvh; for (Definition& def : instr->definitions) fill_vgpr_bitset(*vgprs, def.physReg(), def.bytes()); for (Operand& op : instr->operands) fill_vgpr_bitset(*vgprs, op.physReg(), op.bytes()); } } if (instr->isDS() || instr->isFlat()) { for (Definition& def : instr->definitions) fill_vgpr_bitset(ctx.vgpr_used_by_ds, def.physReg(), def.bytes()); for (Operand& op : instr->operands) fill_vgpr_bitset(ctx.vgpr_used_by_ds, op.physReg(), op.bytes()); } wait_imm imm; if (instr->isVALU() || instr->isEXP() || vm_vsrc == 0) { ctx.vgpr_used_by_vmem_load.reset(); ctx.vgpr_used_by_vmem_sample.reset(); ctx.vgpr_used_by_vmem_bvh.reset(); ctx.vgpr_used_by_vmem_store.reset(); ctx.vgpr_used_by_ds.reset(); } else if (imm.unpack(state.program->gfx_level, instr.get())) { if (imm.vm == 0) ctx.vgpr_used_by_vmem_load.reset(); if (imm.sample == 0) ctx.vgpr_used_by_vmem_sample.reset(); if (imm.bvh == 0) ctx.vgpr_used_by_vmem_bvh.reset(); if (imm.lgkm == 0) ctx.vgpr_used_by_ds.reset(); if (imm.vs == 0) ctx.vgpr_used_by_vmem_store.reset(); } if (instr->isLDSDIR()) { if (ctx.vgpr_used_by_vmem_load[instr->definitions[0].physReg().reg() - 256] || ctx.vgpr_used_by_vmem_sample[instr->definitions[0].physReg().reg() - 256] || ctx.vgpr_used_by_vmem_bvh[instr->definitions[0].physReg().reg() - 256] || ctx.vgpr_used_by_vmem_store[instr->definitions[0].physReg().reg() - 256] || ctx.vgpr_used_by_ds[instr->definitions[0].physReg().reg() - 256]) { if (state.program->gfx_level >= GFX12) instr->ldsdir().wait_vsrc = 0; else bld.sopp(aco_opcode::s_waitcnt_depctr, 0xffe3); ctx.vgpr_used_by_vmem_load.reset(); ctx.vgpr_used_by_vmem_sample.reset(); ctx.vgpr_used_by_vmem_bvh.reset(); ctx.vgpr_used_by_vmem_store.reset(); ctx.vgpr_used_by_ds.reset(); } } /* WMMA Hazards */ if (instr_info.classes[(int)instr->opcode] == instr_class::wmma) { assert(instr->operands.back().regClass() == instr->definitions[0].regClass()); bool is_swmma = instr->operands.size() == 4; if (test_vgpr_bitset(ctx.vgpr_written_by_wmma, instr->operands[0]) || test_vgpr_bitset(ctx.vgpr_written_by_wmma, instr->operands[1]) || (is_swmma && test_vgpr_bitset(ctx.vgpr_written_by_wmma, instr->operands[2]))) { bld.vop1(aco_opcode::v_nop); } ctx.vgpr_written_by_wmma.reset(); fill_vgpr_bitset(ctx.vgpr_written_by_wmma, instr->definitions[0].physReg(), instr->definitions[0].bytes()); } else if (instr->isVALU()) { ctx.vgpr_written_by_wmma.reset(); } } bool has_vdst0_since_valu_instr(bool& global_state, unsigned& block_state, aco_ptr& pred) { if (parse_depctr_wait(pred.get()).va_vdst == 0) return true; if (--block_state == 0) { global_state = false; return true; } if (pred->isVALU()) { bool vgpr_rd_or_wr = false; for (Definition def : pred->definitions) { if (def.physReg().reg() >= 256) vgpr_rd_or_wr = true; } for (Operand op : pred->operands) { if (op.physReg().reg() >= 256) vgpr_rd_or_wr = true; } if (vgpr_rd_or_wr) { global_state = false; return true; } } return false; } void resolve_all_gfx11(State& state, NOP_ctx_gfx11& ctx, std::vector>& new_instructions) { Builder bld(state.program, &new_instructions); unsigned waitcnt_depctr = 0xffff; bool valu_read_sgpr = false; /* LdsDirectVALUHazard/VALUPartialForwardingHazard/VALUTransUseHazard */ bool has_vdst0_since_valu = true; unsigned depth = 16; search_backwards( state, has_vdst0_since_valu, depth); if (!has_vdst0_since_valu) { waitcnt_depctr &= 0x0fff; ctx.valu_since_wr_by_trans.reset(); ctx.trans_since_wr_by_trans.reset(); } /* VcmpxPermlaneHazard/WMMAHazards */ if (ctx.has_Vcmpx || ctx.vgpr_written_by_wmma.any()) { ctx.has_Vcmpx = false; ctx.vgpr_written_by_wmma.reset(); bld.vop1(aco_opcode::v_nop); } /* VALUMaskWriteHazard */ if (state.program->gfx_level < GFX12 && state.program->wave_size == 64) { if (ctx.sgpr_read_by_valu_as_lanemask_then_wr_by_salu.any()) { waitcnt_depctr &= 0xfffe; ctx.sgpr_read_by_valu_as_lanemask_then_wr_by_salu.reset(); } if (ctx.sgpr_read_by_valu_as_lanemask.any()) { valu_read_sgpr = true; ctx.sgpr_read_by_valu_as_lanemask.reset(); } } /* VALUReadSGPRHazard */ if (state.program->gfx_level >= GFX12) { if (!ctx.sgpr_read_by_valu_then_wr_by_salu.empty()) waitcnt_depctr &= 0xfffe; ctx.sgpr_read_by_valu_then_wr_by_salu.reset(); } /* LdsDirectVMEMHazard */ if (ctx.vgpr_used_by_vmem_load.any() || ctx.vgpr_used_by_vmem_store.any() || ctx.vgpr_used_by_ds.any() || ctx.vgpr_used_by_vmem_sample.any() || ctx.vgpr_used_by_vmem_bvh.any()) { waitcnt_depctr &= 0xffe3; ctx.vgpr_used_by_vmem_load.reset(); ctx.vgpr_used_by_vmem_store.reset(); ctx.vgpr_used_by_ds.reset(); } if (waitcnt_depctr != 0xffff) bld.sopp(aco_opcode::s_waitcnt_depctr, waitcnt_depctr); if (valu_read_sgpr) { /* This has to be after the s_waitcnt_depctr so that the instruction is not involved in any * other hazards. */ bld.vop3(aco_opcode::v_xor3_b32, Definition(PhysReg(256), v1), Operand(PhysReg(256), v1), Operand(PhysReg(0), s1), Operand(PhysReg(0), s1)); /* workaround possible LdsDirectVALUHazard/VALUPartialForwardingHazard */ bld.sopp(aco_opcode::s_waitcnt_depctr, 0x0fff); } } template using HandleInstr = void (*)(State& state, Ctx&, aco_ptr&, std::vector>&); template using ResolveAll = void (*)(State& state, Ctx&, std::vector>&); template Handle, ResolveAll Resolve> void handle_block(Program* program, Ctx& ctx, Block& block) { if (block.instructions.empty()) return; State state; state.program = program; state.block = █ state.old_instructions = std::move(block.instructions); block.instructions.clear(); // Silence clang-analyzer-cplusplus.Move warning block.instructions.reserve(state.old_instructions.size()); bool found_end = false; for (aco_ptr& instr : state.old_instructions) { Handle(state, ctx, instr, block.instructions); /* Resolve all possible hazards (we don't know what s_setpc_b64 jumps to). */ if (instr->opcode == aco_opcode::s_setpc_b64) { block.instructions.emplace_back(std::move(instr)); std::vector> resolve_instrs; Resolve(state, ctx, resolve_instrs); block.instructions.insert(std::prev(block.instructions.end()), std::move_iterator(resolve_instrs.begin()), std::move_iterator(resolve_instrs.end())); found_end = true; continue; } found_end |= instr->opcode == aco_opcode::s_endpgm; block.instructions.emplace_back(std::move(instr)); } /* Resolve all possible hazards (we don't know what the shader is concatenated with). */ if (block.linear_succs.empty() && !found_end) Resolve(state, ctx, block.instructions); } template Handle, ResolveAll Resolve> void mitigate_hazards(Program* program, Ctx initial_ctx = Ctx()) { std::vector all_ctx(program->blocks.size()); std::stack> loop_header_indices; for (unsigned i = 0; i < program->blocks.size(); i++) { Block& block = program->blocks[i]; Ctx& ctx = all_ctx[i]; if (i == 0 || (block.kind & block_kind_resume)) ctx = initial_ctx; if (block.kind & block_kind_loop_header) { loop_header_indices.push(i); } else if (block.kind & block_kind_loop_exit) { /* Go through the whole loop again */ for (unsigned idx = loop_header_indices.top(); idx < i; idx++) { Ctx loop_block_ctx; for (unsigned b : program->blocks[idx].linear_preds) loop_block_ctx.join(all_ctx[b]); handle_block(program, loop_block_ctx, program->blocks[idx]); /* We only need to continue if the loop header context changed */ if (idx == loop_header_indices.top() && loop_block_ctx == all_ctx[idx]) break; all_ctx[idx] = loop_block_ctx; } loop_header_indices.pop(); } for (unsigned b : block.linear_preds) ctx.join(all_ctx[b]); handle_block(program, ctx, block); } } /* FeatureRequiredExportPriority in LLVM */ void required_export_priority(Program* program) { /* Skip callees, assuming that the caller has already increased the priority. */ bool increase_priority = !program->is_epilog && !program->info.vs.has_prolog && (!program->info.merged_shader_compiled_separately || program->stage.sw == SWStage::VS || program->stage.sw == SWStage::TES); increase_priority |= program->is_prolog; for (Block& block : program->blocks) { std::vector> new_instructions; new_instructions.reserve(block.instructions.size() + 6); Builder bld(program, &new_instructions); if (increase_priority && block.index == 0) { if (!block.instructions.empty() && block.instructions[0]->opcode == aco_opcode::s_setprio) block.instructions[0]->salu().imm = MAX2(block.instructions[0]->salu().imm, 2); else bld.sopp(aco_opcode::s_setprio, 2); } for (unsigned i = 0; i < block.instructions.size(); i++) { Instruction* instr = block.instructions[i].get(); new_instructions.push_back(std::move(block.instructions[i])); if (instr->opcode == aco_opcode::s_setprio) { instr->salu().imm = MAX2(instr->salu().imm, 2); continue; } bool end_of_export_sequence = instr->isEXP() && (i == block.instructions.size() - 1 || !block.instructions[i + 1]->isEXP()); if (!end_of_export_sequence) continue; bool before_endpgm = false; if (i != block.instructions.size() - 1) { before_endpgm = block.instructions[i + 1]->opcode == aco_opcode::s_endpgm; } else { /* Does this fallthrough to a s_endpgm? */ for (unsigned j = block.index + 1; j < program->blocks.size(); j++) { if (program->blocks[j].instructions.size() == 1 && program->blocks[j].instructions[0]->opcode == aco_opcode::s_endpgm) before_endpgm = true; if (!program->blocks[j].instructions.empty()) break; } } bld.sopp(aco_opcode::s_setprio, 0); if (!before_endpgm) bld.sopk(aco_opcode::s_waitcnt_expcnt, Operand(sgpr_null, s1), 0); bld.sopp(aco_opcode::s_nop, 0); bld.sopp(aco_opcode::s_nop, 0); if (!before_endpgm) bld.sopp(aco_opcode::s_setprio, 2); } block.instructions = std::move(new_instructions); } } } /* end namespace */ void insert_NOPs(Program* program) { if (program->gfx_level >= GFX11) { NOP_ctx_gfx11 initial_ctx; bool has_previous_part = program->is_epilog || program->info.vs.has_prolog || program->info.ps.has_prolog || (program->info.merged_shader_compiled_separately && program->stage.sw != SWStage::VS && program->stage.sw != SWStage::TES) || program->stage == raytracing_cs; if (program->gfx_level >= GFX12 && has_previous_part) { /* resolve_all_gfx11 can't resolve VALUReadSGPRHazard entirely. We have to assume that any * SGPR might have been read by VALU if there was a previous shader part. */ initial_ctx.sgpr_read_by_valu.flip(); } mitigate_hazards(program, initial_ctx); } else if (program->gfx_level >= GFX10_3) { ; /* no hazards/bugs to mitigate */ } else if (program->gfx_level >= GFX10) { mitigate_hazards(program); } else { mitigate_hazards(program); } if (program->gfx_level == GFX11_5 && (program->stage.hw == AC_HW_NEXT_GEN_GEOMETRY_SHADER || program->stage.hw == AC_HW_PIXEL_SHADER)) required_export_priority(program); } } // namespace aco