/* * Copyright (C) 2020 Collabora, Ltd. * * 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 "compiler.h" /* This file contains the final passes of the compiler. Running after * scheduling and RA, the IR is now finalized, so we need to emit it to actual * bits on the wire (as well as fixup branches) */ static uint64_t bi_pack_header(bi_clause *clause, bi_clause *next_1, bi_clause *next_2) { /* next_dependencies are the union of the dependencies of successors' * dependencies */ unsigned dependency_wait = next_1 ? next_1->dependencies : 0; dependency_wait |= next_2 ? next_2->dependencies : 0; bool staging_barrier = next_1 ? next_1->staging_barrier : false; staging_barrier |= next_2 ? next_2->staging_barrier : 0; struct bifrost_header header = { .flow_control = (next_1 == NULL && next_2 == NULL) ? BIFROST_FLOW_END : clause->flow_control, .terminate_discarded_threads = clause->td, .next_clause_prefetch = clause->next_clause_prefetch && next_1, .staging_barrier = staging_barrier, .staging_register = clause->staging_register, .dependency_wait = dependency_wait, .dependency_slot = clause->scoreboard_id, .message_type = clause->message_type, .next_message_type = next_1 ? next_1->message_type : 0, }; uint64_t u = 0; memcpy(&u, &header, sizeof(header)); return u; } /* Assigns a slot for reading, before anything is written */ static void bi_assign_slot_read(bi_registers *regs, bi_index src) { /* We only assign for registers */ if (src.type != BI_INDEX_REGISTER) return; /* Check if we already assigned the slot */ for (unsigned i = 0; i <= 1; ++i) { if (regs->slot[i] == src.value && regs->enabled[i]) return; } if (regs->slot[2] == src.value && regs->slot23.slot2 == BIFROST_OP_READ) return; /* Assign it now */ for (unsigned i = 0; i <= 1; ++i) { if (!regs->enabled[i]) { regs->slot[i] = src.value; regs->enabled[i] = true; return; } } if (!regs->slot23.slot3) { regs->slot[2] = src.value; regs->slot23.slot2 = BIFROST_OP_READ; return; } bi_print_slots(regs, stderr); unreachable("Failed to find a free slot for src"); } static bi_registers bi_assign_slots(bi_tuple *now, bi_tuple *prev) { /* We assign slots for the main register mechanism. Special ops * use the data registers, which has its own mechanism entirely * and thus gets skipped over here. */ bool read_dreg = now->add && bi_opcode_props[now->add->op].sr_read; bool write_dreg = prev->add && bi_opcode_props[prev->add->op].sr_write; /* First, assign reads */ if (now->fma) bi_foreach_src(now->fma, src) bi_assign_slot_read(&now->regs, (now->fma)->src[src]); if (now->add) { bi_foreach_src(now->add, src) { if (!(src == 0 && read_dreg)) bi_assign_slot_read(&now->regs, (now->add)->src[src]); } } /* Next, assign writes. Staging writes are assigned separately, but * +ATEST wants its destination written to both a staging register * _and_ a regular write, because it may not generate a message */ if (prev->add && (!write_dreg || prev->add->op == BI_OPCODE_ATEST)) { bi_index idx = prev->add->dest[0]; if (idx.type == BI_INDEX_REGISTER) { now->regs.slot[3] = idx.value; now->regs.slot23.slot3 = BIFROST_OP_WRITE; } } if (prev->fma) { bi_index idx = (prev->fma)->dest[0]; if (idx.type == BI_INDEX_REGISTER) { if (now->regs.slot23.slot3) { /* Scheduler constraint: cannot read 3 and write 2 */ assert(!now->regs.slot23.slot2); now->regs.slot[2] = idx.value; now->regs.slot23.slot2 = BIFROST_OP_WRITE; } else { now->regs.slot[3] = idx.value; now->regs.slot23.slot3 = BIFROST_OP_WRITE; now->regs.slot23.slot3_fma = true; } } } return now->regs; } static enum bifrost_reg_mode bi_pack_register_mode(bi_registers r) { /* Handle idle as a special case */ if (!(r.slot23.slot2 | r.slot23.slot3)) return r.first_instruction ? BIFROST_IDLE_1 : BIFROST_IDLE; /* Otherwise, use the LUT */ for (unsigned i = 0; i < ARRAY_SIZE(bifrost_reg_ctrl_lut); ++i) { if (memcmp(bifrost_reg_ctrl_lut + i, &r.slot23, sizeof(r.slot23)) == 0) return i; } bi_print_slots(&r, stderr); unreachable("Invalid slot assignment"); } static uint64_t bi_pack_registers(bi_registers regs) { enum bifrost_reg_mode mode = bi_pack_register_mode(regs); struct bifrost_regs s = { 0 }; uint64_t packed = 0; /* Need to pack 5-bit mode as a 4-bit field. The decoder moves bit 3 to bit 4 for * first instruction and adds 16 when reg 2 == reg 3 */ unsigned ctrl; bool r2_equals_r3 = false; if (regs.first_instruction) { /* Bit 3 implicitly must be clear for first instructions. * The affected patterns all write both ADD/FMA, but that * is forbidden for the last instruction (whose writes are * encoded by the first), so this does not add additional * encoding constraints */ assert(!(mode & 0x8)); /* Move bit 4 to bit 3, since bit 3 is clear */ ctrl = (mode & 0x7) | ((mode & 0x10) >> 1); /* If we can let r2 equal r3, we have to or the hardware raises * INSTR_INVALID_ENC (it's unclear why). */ if (!(regs.slot23.slot2 && regs.slot23.slot3)) r2_equals_r3 = true; } else { /* We force r2=r3 or not for the upper bit */ ctrl = (mode & 0xF); r2_equals_r3 = (mode & 0x10); } if (regs.enabled[1]) { /* Gotta save that bit!~ Required by the 63-x trick */ assert(regs.slot[1] > regs.slot[0]); assert(regs.enabled[0]); /* Do the 63-x trick, see docs/disasm */ if (regs.slot[0] > 31) { regs.slot[0] = 63 - regs.slot[0]; regs.slot[1] = 63 - regs.slot[1]; } assert(regs.slot[0] <= 31); assert(regs.slot[1] <= 63); s.ctrl = ctrl; s.reg1 = regs.slot[1]; s.reg0 = regs.slot[0]; } else { /* slot 1 disabled, so set to zero and use slot 1 for ctrl */ s.ctrl = 0; s.reg1 = ctrl << 2; if (regs.enabled[0]) { /* Bit 0 upper bit of slot 0 */ s.reg1 |= (regs.slot[0] >> 5); /* Rest of slot 0 in usual spot */ s.reg0 = (regs.slot[0] & 0b11111); } else { /* Bit 1 set if slot 0 also disabled */ s.reg1 |= (1 << 1); } } /* Force r2 =/!= r3 as needed */ if (r2_equals_r3) { assert(regs.slot[3] == regs.slot[2] || !(regs.slot23.slot2 && regs.slot23.slot3)); if (regs.slot23.slot2) regs.slot[3] = regs.slot[2]; else regs.slot[2] = regs.slot[3]; } else if (!regs.first_instruction) { /* Enforced by the encoding anyway */ assert(regs.slot[2] != regs.slot[3]); } s.reg2 = regs.slot[2]; s.reg3 = regs.slot[3]; s.fau_idx = regs.fau_idx; memcpy(&packed, &s, sizeof(s)); return packed; } /* We must ensure slot 1 > slot 0 for the 63-x trick to function, so we fix * this up at pack time. (Scheduling doesn't care.) */ static void bi_flip_slots(bi_registers *regs) { if (regs->enabled[0] && regs->enabled[1] && regs->slot[1] < regs->slot[0]) { unsigned temp = regs->slot[0]; regs->slot[0] = regs->slot[1]; regs->slot[1] = temp; } } static inline enum bifrost_packed_src bi_get_src_slot(bi_registers *regs, unsigned reg) { if (regs->slot[0] == reg && regs->enabled[0]) return BIFROST_SRC_PORT0; else if (regs->slot[1] == reg && regs->enabled[1]) return BIFROST_SRC_PORT1; else if (regs->slot[2] == reg && regs->slot23.slot2 == BIFROST_OP_READ) return BIFROST_SRC_PORT2; else unreachable("Tried to access register with no port"); } static inline enum bifrost_packed_src bi_get_src_new(bi_instr *ins, bi_registers *regs, unsigned s) { if (!ins) return 0; bi_index src = ins->src[s]; if (src.type == BI_INDEX_REGISTER) return bi_get_src_slot(regs, src.value); else if (src.type == BI_INDEX_PASS) return src.value; else if (bi_is_null(src) && ins->op == BI_OPCODE_ZS_EMIT && s < 2) return BIFROST_SRC_STAGE; else { /* TODO make safer */ return BIFROST_SRC_STAGE; } } static struct bi_packed_tuple bi_pack_tuple(bi_clause *clause, bi_tuple *tuple, bi_tuple *prev, bool first_tuple, gl_shader_stage stage) { bi_assign_slots(tuple, prev); tuple->regs.fau_idx = tuple->fau_idx; tuple->regs.first_instruction = first_tuple; bi_flip_slots(&tuple->regs); bool sr_read = tuple->add && bi_opcode_props[(tuple->add)->op].sr_read; uint64_t reg = bi_pack_registers(tuple->regs); uint64_t fma = bi_pack_fma(tuple->fma, bi_get_src_new(tuple->fma, &tuple->regs, 0), bi_get_src_new(tuple->fma, &tuple->regs, 1), bi_get_src_new(tuple->fma, &tuple->regs, 2), bi_get_src_new(tuple->fma, &tuple->regs, 3)); uint64_t add = bi_pack_add(tuple->add, bi_get_src_new(tuple->add, &tuple->regs, sr_read + 0), bi_get_src_new(tuple->add, &tuple->regs, sr_read + 1), bi_get_src_new(tuple->add, &tuple->regs, sr_read + 2), 0); if (tuple->add) { bi_instr *add = tuple->add; bool sr_write = bi_opcode_props[add->op].sr_write && !bi_is_null(add->dest[0]); if (sr_read && !bi_is_null(add->src[0])) { assert(add->src[0].type == BI_INDEX_REGISTER); clause->staging_register = add->src[0].value; if (sr_write) assert(bi_is_equiv(add->src[0], add->dest[0])); } else if (sr_write) { assert(add->dest[0].type == BI_INDEX_REGISTER); clause->staging_register = add->dest[0].value; } } struct bi_packed_tuple packed = { .lo = reg | (fma << 35) | ((add & 0b111111) << 58), .hi = add >> 6 }; return packed; } /* A block contains at most one PC-relative constant, from a terminal branch. * Find the last instruction and if it is a relative branch, fix up the * PC-relative constant to contain the absolute offset. This occurs at pack * time instead of schedule time because the number of quadwords between each * block is not known until after all other passes have finished. */ static void bi_assign_branch_offset(bi_context *ctx, bi_block *block) { if (list_is_empty(&block->clauses)) return; bi_clause *clause = list_last_entry(&block->clauses, bi_clause, link); bi_instr *br = bi_last_instr_in_clause(clause); if (!br->branch_target) return; /* Put it in the high place */ int32_t qwords = bi_block_offset(ctx, clause, br->branch_target); int32_t bytes = qwords * 16; /* Copy so we can toy with the sign without undefined behaviour */ uint32_t raw = 0; memcpy(&raw, &bytes, sizeof(raw)); /* Clear off top bits for A1/B1 bits */ raw &= ~0xF0000000; /* Put in top 32-bits */ assert(clause->pcrel_idx < 8); clause->constants[clause->pcrel_idx] |= ((uint64_t) raw) << 32ull; } static void bi_pack_constants(unsigned tuple_count, uint64_t *constants, unsigned word_idx, unsigned constant_words, bool ec0_packed, struct util_dynarray *emission) { unsigned index = (word_idx << 1) + ec0_packed; /* Do more constants follow */ bool more = (word_idx + 1) < constant_words; /* Indexed first by tuple count and second by constant word number, * indicates the position in the clause */ unsigned pos_lookup[8][3] = { { 0 }, { 1 }, { 3 }, { 2, 5 }, { 4, 8 }, { 7, 11, 14 }, { 6, 10, 13 }, { 9, 12 } }; /* Compute the pos, and check everything is reasonable */ assert((tuple_count - 1) < 8); assert(word_idx < 3); unsigned pos = pos_lookup[tuple_count - 1][word_idx]; assert(pos != 0 || (tuple_count == 1 && word_idx == 0)); struct bifrost_fmt_constant quad = { .pos = pos, .tag = more ? BIFROST_FMTC_CONSTANTS : BIFROST_FMTC_FINAL, .imm_1 = constants[index + 0] >> 4, .imm_2 = constants[index + 1] >> 4, }; util_dynarray_append(emission, struct bifrost_fmt_constant, quad); } uint8_t bi_pack_literal(enum bi_clause_subword literal) { assert(literal >= BI_CLAUSE_SUBWORD_LITERAL_0); assert(literal <= BI_CLAUSE_SUBWORD_LITERAL_7); return (literal - BI_CLAUSE_SUBWORD_LITERAL_0); } static inline uint8_t bi_clause_upper(unsigned val, struct bi_packed_tuple *tuples, ASSERTED unsigned tuple_count) { assert(val < tuple_count); /* top 3-bits of 78-bits is tuple >> 75 == (tuple >> 64) >> 11 */ struct bi_packed_tuple tuple = tuples[val]; return (tuple.hi >> 11); } uint8_t bi_pack_upper(enum bi_clause_subword upper, struct bi_packed_tuple *tuples, ASSERTED unsigned tuple_count) { assert(upper >= BI_CLAUSE_SUBWORD_UPPER_0); assert(upper <= BI_CLAUSE_SUBWORD_UPPER_7); return bi_clause_upper(upper - BI_CLAUSE_SUBWORD_UPPER_0, tuples, tuple_count); } uint64_t bi_pack_tuple_bits(enum bi_clause_subword idx, struct bi_packed_tuple *tuples, ASSERTED unsigned tuple_count, unsigned offset, unsigned nbits) { assert(idx >= BI_CLAUSE_SUBWORD_TUPLE_0); assert(idx <= BI_CLAUSE_SUBWORD_TUPLE_7); unsigned val = (idx - BI_CLAUSE_SUBWORD_TUPLE_0); assert(val < tuple_count); struct bi_packed_tuple tuple = tuples[val]; assert(offset + nbits < 78); assert(nbits <= 64); /* (X >> start) & m * = (((hi << 64) | lo) >> start) & m * = (((hi << 64) >> start) | (lo >> start)) & m * = { ((hi << (64 - start)) | (lo >> start)) & m if start <= 64 * { ((hi >> (start - 64)) | (lo >> start)) & m if start >= 64 * = { ((hi << (64 - start)) & m) | ((lo >> start) & m) if start <= 64 * { ((hi >> (start - 64)) & m) | ((lo >> start) & m) if start >= 64 * * By setting m = 2^64 - 1, we justify doing the respective shifts as * 64-bit integers. Zero special cased to avoid undefined behaviour. */ uint64_t lo = (tuple.lo >> offset); uint64_t hi = (offset == 0) ? 0 : (offset > 64) ? (tuple.hi >> (offset - 64)) : (tuple.hi << (64 - offset)); return (lo | hi) & ((1ULL << nbits) - 1); } static inline uint16_t bi_pack_lu(enum bi_clause_subword word, struct bi_packed_tuple *tuples, ASSERTED unsigned tuple_count) { return (word >= BI_CLAUSE_SUBWORD_UPPER_0) ? bi_pack_upper(word, tuples, tuple_count) : bi_pack_literal(word); } uint8_t bi_pack_sync(enum bi_clause_subword t1, enum bi_clause_subword t2, enum bi_clause_subword t3, struct bi_packed_tuple *tuples, ASSERTED unsigned tuple_count, bool z) { uint8_t sync = (bi_pack_lu(t3, tuples, tuple_count) << 0) | (bi_pack_lu(t2, tuples, tuple_count) << 3); if (t1 == BI_CLAUSE_SUBWORD_Z) sync |= z << 6; else sync |= bi_pack_literal(t1) << 6; return sync; } static inline uint64_t bi_pack_t_ec(enum bi_clause_subword word, struct bi_packed_tuple *tuples, ASSERTED unsigned tuple_count, uint64_t ec0) { if (word == BI_CLAUSE_SUBWORD_CONSTANT) return ec0; else return bi_pack_tuple_bits(word, tuples, tuple_count, 0, 60); } static uint32_t bi_pack_subwords_56(enum bi_clause_subword t, struct bi_packed_tuple *tuples, ASSERTED unsigned tuple_count, uint64_t header, uint64_t ec0, unsigned tuple_subword) { switch (t) { case BI_CLAUSE_SUBWORD_HEADER: return (header & ((1 << 30) - 1)); case BI_CLAUSE_SUBWORD_RESERVED: return 0; case BI_CLAUSE_SUBWORD_CONSTANT: return (ec0 >> 15) & ((1 << 30) - 1); default: return bi_pack_tuple_bits(t, tuples, tuple_count, tuple_subword * 15, 30); } } static uint16_t bi_pack_subword(enum bi_clause_subword t, unsigned format, struct bi_packed_tuple *tuples, ASSERTED unsigned tuple_count, uint64_t header, uint64_t ec0, unsigned m0, unsigned tuple_subword) { switch (t) { case BI_CLAUSE_SUBWORD_HEADER: return header >> 30; case BI_CLAUSE_SUBWORD_M: return m0; case BI_CLAUSE_SUBWORD_CONSTANT: return (format == 5 || format == 10) ? (ec0 & ((1 << 15) - 1)) : (ec0 >> (15 + 30)); case BI_CLAUSE_SUBWORD_UPPER_23: return (bi_clause_upper(2, tuples, tuple_count) << 12) | (bi_clause_upper(3, tuples, tuple_count) << 9); case BI_CLAUSE_SUBWORD_UPPER_56: return (bi_clause_upper(5, tuples, tuple_count) << 12) | (bi_clause_upper(6, tuples, tuple_count) << 9); case BI_CLAUSE_SUBWORD_UPPER_0 ... BI_CLAUSE_SUBWORD_UPPER_7: return bi_pack_upper(t, tuples, tuple_count) << 12; default: return bi_pack_tuple_bits(t, tuples, tuple_count, tuple_subword * 15, 15); } } /* EC0 is 60-bits (bottom 4 already shifted off) */ void bi_pack_format(struct util_dynarray *emission, unsigned index, struct bi_packed_tuple *tuples, ASSERTED unsigned tuple_count, uint64_t header, uint64_t ec0, unsigned m0, bool z) { struct bi_clause_format format = bi_clause_formats[index]; uint8_t sync = bi_pack_sync(format.tag_1, format.tag_2, format.tag_3, tuples, tuple_count, z); uint64_t s0_s3 = bi_pack_t_ec(format.s0_s3, tuples, tuple_count, ec0); uint16_t s4 = bi_pack_subword(format.s4, format.format, tuples, tuple_count, header, ec0, m0, 4); uint32_t s5_s6 = bi_pack_subwords_56(format.s5_s6, tuples, tuple_count, header, ec0, (format.format == 2 || format.format == 7) ? 0 : 3); uint64_t s7 = bi_pack_subword(format.s7, format.format, tuples, tuple_count, header, ec0, m0, 2); /* Now that subwords are packed, split into 64-bit halves and emit */ uint64_t lo = sync | ((s0_s3 & ((1ull << 56) - 1)) << 8); uint64_t hi = (s0_s3 >> 56) | ((uint64_t) s4 << 4) | ((uint64_t) s5_s6 << 19) | ((uint64_t) s7 << 49); util_dynarray_append(emission, uint64_t, lo); util_dynarray_append(emission, uint64_t, hi); } static void bi_pack_clause(bi_context *ctx, bi_clause *clause, bi_clause *next_1, bi_clause *next_2, struct util_dynarray *emission, gl_shader_stage stage) { struct bi_packed_tuple ins[8] = { 0 }; for (unsigned i = 0; i < clause->tuple_count; ++i) { unsigned prev = ((i == 0) ? clause->tuple_count : i) - 1; ins[i] = bi_pack_tuple(clause, &clause->tuples[i], &clause->tuples[prev], i == 0, stage); } bool ec0_packed = bi_ec0_packed(clause->tuple_count); if (ec0_packed) clause->constant_count = MAX2(clause->constant_count, 1); unsigned constant_quads = DIV_ROUND_UP(clause->constant_count - (ec0_packed ? 1 : 0), 2); uint64_t header = bi_pack_header(clause, next_1, next_2); uint64_t ec0 = (clause->constants[0] >> 4); unsigned m0 = (clause->pcrel_idx == 0) ? 4 : 0; unsigned counts[8] = { 1, 2, 3, 3, 4, 5, 5, 6 }; unsigned indices[8][6] = { { 1 }, { 0, 2 }, { 0, 3, 4 }, { 0, 3, 6 }, { 0, 3, 7, 8 }, { 0, 3, 5, 9, 10 }, { 0, 3, 5, 9, 11 }, { 0, 3, 5, 9, 12, 13 }, }; unsigned count = counts[clause->tuple_count - 1]; for (unsigned pos = 0; pos < count; ++pos) { ASSERTED unsigned idx = indices[clause->tuple_count - 1][pos]; assert(bi_clause_formats[idx].pos == pos); assert((bi_clause_formats[idx].tag_1 == BI_CLAUSE_SUBWORD_Z) == (pos == count - 1)); /* Whether to end the clause immediately after the last tuple */ bool z = (constant_quads == 0); bi_pack_format(emission, indices[clause->tuple_count - 1][pos], ins, clause->tuple_count, header, ec0, m0, z); } /* Pack the remaining constants */ for (unsigned pos = 0; pos < constant_quads; ++pos) { bi_pack_constants(clause->tuple_count, clause->constants, pos, constant_quads, ec0_packed, emission); } } static void bi_collect_blend_ret_addr(bi_context *ctx, struct util_dynarray *emission, const bi_clause *clause) { /* No need to collect return addresses when we're in a blend shader. */ if (ctx->inputs->is_blend) return; const bi_tuple *tuple = &clause->tuples[clause->tuple_count - 1]; const bi_instr *ins = tuple->add; if (!ins || ins->op != BI_OPCODE_BLEND) return; unsigned loc = tuple->regs.fau_idx - BIR_FAU_BLEND_0; assert(loc < ARRAY_SIZE(ctx->info->bifrost.blend)); assert(!ctx->info->bifrost.blend[loc].return_offset); ctx->info->bifrost.blend[loc].return_offset = util_dynarray_num_elements(emission, uint8_t); assert(!(ctx->info->bifrost.blend[loc].return_offset & 0x7)); } unsigned bi_pack(bi_context *ctx, struct util_dynarray *emission) { unsigned previous_size = emission->size; bi_foreach_block(ctx, block) { bi_assign_branch_offset(ctx, block); bi_foreach_clause_in_block(block, clause) { bool is_last = (clause->link.next == &block->clauses); /* Get the succeeding clauses, either two successors of * the block for the last clause in the block or just * the next clause within the block */ bi_clause *next = NULL, *next_2 = NULL; if (is_last) { next = bi_next_clause(ctx, block->successors[0], NULL); next_2 = bi_next_clause(ctx, block->successors[1], NULL); } else { next = bi_next_clause(ctx, block, clause); } previous_size = emission->size; bi_pack_clause(ctx, clause, next, next_2, emission, ctx->stage); if (!is_last) bi_collect_blend_ret_addr(ctx, emission, clause); } } return emission->size - previous_size; }