/* * Copyright(c) 2019-2023 Qualcomm Innovation Center, Inc. All Rights Reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . */ #include "qemu/osdep.h" #include "iclass.h" #include "attribs.h" #include "genptr.h" #include "decode.h" #include "insn.h" #include "printinsn.h" #include "mmvec/decode_ext_mmvec.h" #define fZXTN(N, M, VAL) ((VAL) & ((1LL << (N)) - 1)) enum { EXT_IDX_noext = 0, EXT_IDX_noext_AFTER = 4, EXT_IDX_mmvec = 4, EXT_IDX_mmvec_AFTER = 8, XX_LAST_EXT_IDX }; /* * Certain operand types represent a non-contiguous set of values. * For example, the compound compare-and-jump instruction can only access * registers R0-R7 and R16-23. * This table represents the mapping from the encoding to the actual values. */ #define DEF_REGMAP(NAME, ELEMENTS, ...) \ static const unsigned int DECODE_REGISTER_##NAME[ELEMENTS] = \ { __VA_ARGS__ }; /* Name Num Table */ DEF_REGMAP(R_16, 16, 0, 1, 2, 3, 4, 5, 6, 7, 16, 17, 18, 19, 20, 21, 22, 23) DEF_REGMAP(R__8, 8, 0, 2, 4, 6, 16, 18, 20, 22) DEF_REGMAP(R_8, 8, 0, 1, 2, 3, 4, 5, 6, 7) #define DECODE_MAPPED_REG(OPNUM, NAME) \ insn->regno[OPNUM] = DECODE_REGISTER_##NAME[insn->regno[OPNUM]]; /* Helper functions for decode_*_generated.c.inc */ #define DECODE_MAPPED(NAME) \ static int decode_mapped_reg_##NAME(DisasContext *ctx, int x) \ { \ return DECODE_REGISTER_##NAME[x]; \ } DECODE_MAPPED(R_16) DECODE_MAPPED(R_8) DECODE_MAPPED(R__8) /* Helper function for decodetree_trans_funcs_generated.c.inc */ static int shift_left(DisasContext *ctx, int x, int n, int immno) { int ret = x; Insn *insn = ctx->insn; if (!insn->extension_valid || insn->which_extended != immno) { ret <<= n; } return ret; } /* Include the generated decoder for 32 bit insn */ #include "decode_normal_generated.c.inc" #include "decode_hvx_generated.c.inc" /* Include the generated decoder for 16 bit insn */ #include "decode_subinsn_a_generated.c.inc" #include "decode_subinsn_l1_generated.c.inc" #include "decode_subinsn_l2_generated.c.inc" #include "decode_subinsn_s1_generated.c.inc" #include "decode_subinsn_s2_generated.c.inc" /* Include the generated helpers for the decoder */ #include "decodetree_trans_funcs_generated.c.inc" void decode_send_insn_to(Packet *packet, int start, int newloc) { Insn tmpinsn; int direction; int i; if (start == newloc) { return; } if (start < newloc) { /* Move towards end */ direction = 1; } else { /* move towards beginning */ direction = -1; } for (i = start; i != newloc; i += direction) { tmpinsn = packet->insn[i]; packet->insn[i] = packet->insn[i + direction]; packet->insn[i + direction] = tmpinsn; } } /* Fill newvalue registers with the correct regno */ static void decode_fill_newvalue_regno(Packet *packet) { int i, use_regidx, offset, def_idx, dst_idx; for (i = 1; i < packet->num_insns; i++) { if (GET_ATTRIB(packet->insn[i].opcode, A_DOTNEWVALUE) && !GET_ATTRIB(packet->insn[i].opcode, A_EXTENSION)) { g_assert(packet->insn[i].new_read_idx != -1); use_regidx = packet->insn[i].new_read_idx; /* * What's encoded at the N-field is the offset to who's producing * the value. Shift off the LSB which indicates odd/even register, * then walk backwards and skip over the constant extenders. */ offset = packet->insn[i].regno[use_regidx] >> 1; def_idx = i - offset; for (int j = 0; j < offset; j++) { if (GET_ATTRIB(packet->insn[i - j - 1].opcode, A_IT_EXTENDER)) { def_idx--; } } /* * Check for a badly encoded N-field which points to an instruction * out-of-range */ g_assert(!((def_idx < 0) || (def_idx > (packet->num_insns - 1)))); /* Now patch up the consumer with the register number */ g_assert(packet->insn[def_idx].dest_idx != -1); dst_idx = packet->insn[def_idx].dest_idx; packet->insn[i].regno[use_regidx] = packet->insn[def_idx].regno[dst_idx]; /* * We need to remember who produces this value to later * check if it was dynamically cancelled */ packet->insn[i].new_value_producer_slot = packet->insn[def_idx].slot; } } } /* Split CJ into a compare and a jump */ static void decode_split_cmpjump(Packet *pkt) { int last, i; int numinsns = pkt->num_insns; /* * First, split all compare-jumps. * The compare is sent to the end as a new instruction. * Do it this way so we don't reorder dual jumps. Those need to stay in * original order. */ for (i = 0; i < numinsns; i++) { /* It's a cmp-jump */ if (GET_ATTRIB(pkt->insn[i].opcode, A_NEWCMPJUMP)) { last = pkt->num_insns; pkt->insn[last] = pkt->insn[i]; /* copy the instruction */ pkt->insn[last].part1 = true; /* last insn does the CMP */ pkt->insn[i].part1 = false; /* existing insn does the JUMP */ pkt->num_insns++; } } /* Now re-shuffle all the compares back to the beginning */ for (i = 0; i < pkt->num_insns; i++) { if (pkt->insn[i].part1) { decode_send_insn_to(pkt, i, 0); } } } static bool decode_opcode_can_jump(int opcode) { if ((GET_ATTRIB(opcode, A_JUMP)) || (GET_ATTRIB(opcode, A_CALL)) || (opcode == J2_trap0) || (opcode == J2_pause)) { /* Exception to A_JUMP attribute */ if (opcode == J4_hintjumpr) { return false; } return true; } return false; } static bool decode_opcode_ends_loop(int opcode) { return GET_ATTRIB(opcode, A_HWLOOP0_END) || GET_ATTRIB(opcode, A_HWLOOP1_END); } /* Set the is_* fields in each instruction */ static void decode_set_insn_attr_fields(Packet *pkt) { int i; int numinsns = pkt->num_insns; uint16_t opcode; pkt->pkt_has_cof = false; pkt->pkt_has_multi_cof = false; pkt->pkt_has_endloop = false; pkt->pkt_has_dczeroa = false; for (i = 0; i < numinsns; i++) { opcode = pkt->insn[i].opcode; if (pkt->insn[i].part1) { continue; /* Skip compare of cmp-jumps */ } if (GET_ATTRIB(opcode, A_DCZEROA)) { pkt->pkt_has_dczeroa = true; } if (GET_ATTRIB(opcode, A_STORE)) { if (GET_ATTRIB(opcode, A_SCALAR_STORE) && !GET_ATTRIB(opcode, A_MEMSIZE_0B)) { if (pkt->insn[i].slot == 0) { pkt->pkt_has_store_s0 = true; } else { pkt->pkt_has_store_s1 = true; } } } if (decode_opcode_can_jump(opcode)) { if (pkt->pkt_has_cof) { pkt->pkt_has_multi_cof = true; } pkt->pkt_has_cof = true; } pkt->insn[i].is_endloop = decode_opcode_ends_loop(opcode); pkt->pkt_has_endloop |= pkt->insn[i].is_endloop; if (pkt->pkt_has_endloop) { if (pkt->pkt_has_cof) { pkt->pkt_has_multi_cof = true; } pkt->pkt_has_cof = true; } } } /* * Shuffle for execution * Move stores to end (in same order as encoding) * Move compares to beginning (for use by .new insns) */ static void decode_shuffle_for_execution(Packet *packet) { bool changed = false; int i; bool flag; /* flag means we've seen a non-memory instruction */ int n_mems; int last_insn = packet->num_insns - 1; /* * Skip end loops, somehow an end loop is getting in and messing * up the order */ if (decode_opcode_ends_loop(packet->insn[last_insn].opcode)) { last_insn--; } do { changed = false; /* * Stores go last, must not reorder. * Cannot shuffle stores past loads, either. * Iterate backwards. If we see a non-memory instruction, * then a store, shuffle the store to the front. Don't shuffle * stores wrt each other or a load. */ for (flag = false, n_mems = 0, i = last_insn; i >= 0; i--) { int opcode = packet->insn[i].opcode; if (flag && GET_ATTRIB(opcode, A_STORE)) { decode_send_insn_to(packet, i, last_insn - n_mems); n_mems++; changed = true; } else if (GET_ATTRIB(opcode, A_STORE)) { n_mems++; } else if (GET_ATTRIB(opcode, A_LOAD)) { /* * Don't set flag, since we don't want to shuffle a * store past a load */ n_mems++; } else if (GET_ATTRIB(opcode, A_DOTNEWVALUE)) { /* * Don't set flag, since we don't want to shuffle past * a .new value */ } else { flag = true; } } if (changed) { continue; } /* Compares go first, may be reordered wrt each other */ for (flag = false, i = 0; i < last_insn + 1; i++) { int opcode = packet->insn[i].opcode; if (packet->insn[i].has_pred_dest && GET_ATTRIB(opcode, A_STORE) == 0) { /* This should be a compare (not a store conditional) */ if (flag) { decode_send_insn_to(packet, i, 0); changed = true; continue; } } else if (GET_ATTRIB(opcode, A_IMPLICIT_WRITES_P3) && !decode_opcode_ends_loop(packet->insn[i].opcode)) { /* * spNloop instruction * Don't reorder endloops; they are not valid for .new uses, * and we want to match HW */ if (flag) { decode_send_insn_to(packet, i, 0); changed = true; continue; } } else if (GET_ATTRIB(opcode, A_IMPLICIT_WRITES_P0) && !GET_ATTRIB(opcode, A_NEWCMPJUMP)) { if (flag) { decode_send_insn_to(packet, i, 0); changed = true; continue; } } else { flag = true; } } if (changed) { continue; } } while (changed); /* * If we have a .new register compare/branch, move that to the very * very end, past stores */ for (i = 0; i < last_insn; i++) { if (GET_ATTRIB(packet->insn[i].opcode, A_DOTNEWVALUE)) { decode_send_insn_to(packet, i, last_insn); break; } } } static void apply_extender(Packet *pkt, int i, uint32_t extender) { int immed_num; uint32_t base_immed; immed_num = pkt->insn[i].which_extended; base_immed = pkt->insn[i].immed[immed_num]; pkt->insn[i].immed[immed_num] = extender | fZXTN(6, 32, base_immed); } static void decode_apply_extenders(Packet *packet) { int i; for (i = 0; i < packet->num_insns; i++) { if (GET_ATTRIB(packet->insn[i].opcode, A_IT_EXTENDER)) { packet->insn[i + 1].extension_valid = true; apply_extender(packet, i + 1, packet->insn[i].immed[0]); } } } static void decode_remove_extenders(Packet *packet) { int i, j; for (i = 0; i < packet->num_insns; i++) { if (GET_ATTRIB(packet->insn[i].opcode, A_IT_EXTENDER)) { /* Remove this one by moving the remaining instructions down */ for (j = i; (j < packet->num_insns - 1) && (j < INSTRUCTIONS_MAX - 1); j++) { packet->insn[j] = packet->insn[j + 1]; } packet->num_insns--; } } } static SlotMask get_valid_slots(const Packet *pkt, unsigned int slot) { if (GET_ATTRIB(pkt->insn[slot].opcode, A_EXTENSION)) { return mmvec_ext_decode_find_iclass_slots(pkt->insn[slot].opcode); } else { return find_iclass_slots(pkt->insn[slot].opcode, pkt->insn[slot].iclass); } } /* * Section 10.3 of the Hexagon V73 Programmer's Reference Manual * * A duplex is encoded as a 32-bit instruction with bits [15:14] set to 00. * The sub-instructions that comprise a duplex are encoded as 13-bit fields * in the duplex. * * Per table 10-4, the 4-bit duplex iclass is encoded in bits 31:29, 13 */ static uint32_t get_duplex_iclass(uint32_t encoding) { uint32_t iclass = extract32(encoding, 13, 1); iclass = deposit32(iclass, 1, 3, extract32(encoding, 29, 3)); return iclass; } /* * Per table 10-5, the duplex ICLASS field values that specify the group of * each sub-instruction in a duplex * * This table points to the decode instruction for each entry in the table */ typedef bool (*subinsn_decode_func)(DisasContext *ctx, uint16_t insn); typedef struct { subinsn_decode_func decode_slot0_subinsn; subinsn_decode_func decode_slot1_subinsn; } subinsn_decode_groups; static const subinsn_decode_groups decode_groups[16] = { [0x0] = { decode_subinsn_l1, decode_subinsn_l1 }, [0x1] = { decode_subinsn_l2, decode_subinsn_l1 }, [0x2] = { decode_subinsn_l2, decode_subinsn_l2 }, [0x3] = { decode_subinsn_a, decode_subinsn_a }, [0x4] = { decode_subinsn_l1, decode_subinsn_a }, [0x5] = { decode_subinsn_l2, decode_subinsn_a }, [0x6] = { decode_subinsn_s1, decode_subinsn_a }, [0x7] = { decode_subinsn_s2, decode_subinsn_a }, [0x8] = { decode_subinsn_s1, decode_subinsn_l1 }, [0x9] = { decode_subinsn_s1, decode_subinsn_l2 }, [0xa] = { decode_subinsn_s1, decode_subinsn_s1 }, [0xb] = { decode_subinsn_s2, decode_subinsn_s1 }, [0xc] = { decode_subinsn_s2, decode_subinsn_l1 }, [0xd] = { decode_subinsn_s2, decode_subinsn_l2 }, [0xe] = { decode_subinsn_s2, decode_subinsn_s2 }, [0xf] = { NULL, NULL }, /* Reserved */ }; static uint16_t get_slot0_subinsn(uint32_t encoding) { return extract32(encoding, 0, 13); } static uint16_t get_slot1_subinsn(uint32_t encoding) { return extract32(encoding, 16, 13); } static unsigned int decode_insns(DisasContext *ctx, Insn *insn, uint32_t encoding) { if (parse_bits(encoding) != 0) { if (decode_normal(ctx, encoding) || decode_hvx(ctx, encoding)) { insn->generate = opcode_genptr[insn->opcode]; insn->iclass = iclass_bits(encoding); return 1; } g_assert_not_reached(); } else { uint32_t iclass = get_duplex_iclass(encoding); unsigned int slot0_subinsn = get_slot0_subinsn(encoding); unsigned int slot1_subinsn = get_slot1_subinsn(encoding); subinsn_decode_func decode_slot0_subinsn = decode_groups[iclass].decode_slot0_subinsn; subinsn_decode_func decode_slot1_subinsn = decode_groups[iclass].decode_slot1_subinsn; /* The slot1 subinsn needs to be in the packet first */ if (decode_slot1_subinsn(ctx, slot1_subinsn)) { insn->generate = opcode_genptr[insn->opcode]; insn->iclass = iclass_bits(encoding); ctx->insn = ++insn; if (decode_slot0_subinsn(ctx, slot0_subinsn)) { insn->generate = opcode_genptr[insn->opcode]; insn->iclass = iclass_bits(encoding); return 2; } } g_assert_not_reached(); } } static void decode_add_endloop_insn(Insn *insn, int loopnum) { if (loopnum == 10) { insn->opcode = J2_endloop01; insn->generate = opcode_genptr[J2_endloop01]; } else if (loopnum == 1) { insn->opcode = J2_endloop1; insn->generate = opcode_genptr[J2_endloop1]; } else if (loopnum == 0) { insn->opcode = J2_endloop0; insn->generate = opcode_genptr[J2_endloop0]; } else { g_assert_not_reached(); } } static bool decode_parsebits_is_loopend(uint32_t encoding32) { uint32_t bits = parse_bits(encoding32); return bits == 0x2; } static bool has_valid_slot_assignment(Packet *pkt) { int used_slots = 0; for (int i = 0; i < pkt->num_insns; i++) { int slot_mask; Insn *insn = &pkt->insn[i]; if (decode_opcode_ends_loop(insn->opcode)) { /* We overload slot 0 for endloop. */ continue; } slot_mask = 1 << insn->slot; if (used_slots & slot_mask) { return false; } used_slots |= slot_mask; } return true; } static bool decode_set_slot_number(Packet *pkt) { int slot; int i; bool hit_mem_insn = false; bool hit_duplex = false; bool slot0_found = false; bool slot1_found = false; int slot1_iidx = 0; /* * The slots are encoded in reverse order * For each instruction, count down until you find a suitable slot */ for (i = 0, slot = 3; i < pkt->num_insns; i++) { SlotMask valid_slots = get_valid_slots(pkt, i); while (!(valid_slots & (1 << slot))) { slot--; } pkt->insn[i].slot = slot; if (slot) { /* I've assigned the slot, now decrement it for the next insn */ slot--; } } /* Fix the exceptions - mem insns to slot 0,1 */ for (i = pkt->num_insns - 1; i >= 0; i--) { /* First memory instruction always goes to slot 0 */ if ((GET_ATTRIB(pkt->insn[i].opcode, A_MEMLIKE) || GET_ATTRIB(pkt->insn[i].opcode, A_MEMLIKE_PACKET_RULES)) && !hit_mem_insn) { hit_mem_insn = true; pkt->insn[i].slot = 0; continue; } /* Next memory instruction always goes to slot 1 */ if ((GET_ATTRIB(pkt->insn[i].opcode, A_MEMLIKE) || GET_ATTRIB(pkt->insn[i].opcode, A_MEMLIKE_PACKET_RULES)) && hit_mem_insn) { pkt->insn[i].slot = 1; } } /* Fix the exceptions - duplex always slot 0,1 */ for (i = pkt->num_insns - 1; i >= 0; i--) { /* First subinsn always goes to slot 0 */ if (GET_ATTRIB(pkt->insn[i].opcode, A_SUBINSN) && !hit_duplex) { hit_duplex = true; pkt->insn[i].slot = 0; continue; } /* Next subinsn always goes to slot 1 */ if (GET_ATTRIB(pkt->insn[i].opcode, A_SUBINSN) && hit_duplex) { pkt->insn[i].slot = 1; } } /* Fix the exceptions - slot 1 is never empty, always aligns to slot 0 */ for (i = pkt->num_insns - 1; i >= 0; i--) { /* Is slot0 used? */ if (pkt->insn[i].slot == 0) { bool is_endloop = (pkt->insn[i].opcode == J2_endloop01); is_endloop |= (pkt->insn[i].opcode == J2_endloop0); is_endloop |= (pkt->insn[i].opcode == J2_endloop1); /* * Make sure it's not endloop since, we're overloading * slot0 for endloop */ if (!is_endloop) { slot0_found = true; } } /* Is slot1 used? */ if (pkt->insn[i].slot == 1) { slot1_found = true; slot1_iidx = i; } } /* Is slot0 empty and slot1 used? */ if ((!slot0_found) && slot1_found) { /* Then push it to slot0 */ pkt->insn[slot1_iidx].slot = 0; } return has_valid_slot_assignment(pkt); } /* * decode_packet * Decodes packet with given words * Returns 0 on insufficient words, * or number of words used on success */ int decode_packet(DisasContext *ctx, int max_words, const uint32_t *words, Packet *pkt, bool disas_only) { int num_insns = 0; int words_read = 0; bool end_of_packet = false; int new_insns = 0; int i; uint32_t encoding32; /* Initialize */ memset(pkt, 0, sizeof(*pkt)); /* Try to build packet */ while (!end_of_packet && (words_read < max_words)) { Insn *insn = &pkt->insn[num_insns]; ctx->insn = insn; encoding32 = words[words_read]; end_of_packet = is_packet_end(encoding32); new_insns = decode_insns(ctx, insn, encoding32); g_assert(new_insns > 0); /* * If we saw an extender, mark next word extended so immediate * decode works */ if (pkt->insn[num_insns].opcode == A4_ext) { pkt->insn[num_insns + 1].extension_valid = true; } num_insns += new_insns; words_read++; } pkt->num_insns = num_insns; if (!end_of_packet) { /* Ran out of words! */ return 0; } pkt->encod_pkt_size_in_bytes = words_read * 4; pkt->pkt_has_hvx = false; for (i = 0; i < num_insns; i++) { pkt->pkt_has_hvx |= GET_ATTRIB(pkt->insn[i].opcode, A_CVI); } /* * Check for :endloop in the parse bits * Section 10.6 of the Programmer's Reference describes the encoding * The end of hardware loop 0 can be encoded with 2 words * The end of hardware loop 1 needs 3 words */ if ((words_read == 2) && (decode_parsebits_is_loopend(words[0]))) { decode_add_endloop_insn(&pkt->insn[pkt->num_insns++], 0); } if (words_read >= 3) { bool has_loop0, has_loop1; has_loop0 = decode_parsebits_is_loopend(words[0]); has_loop1 = decode_parsebits_is_loopend(words[1]); if (has_loop0 && has_loop1) { decode_add_endloop_insn(&pkt->insn[pkt->num_insns++], 10); } else if (has_loop1) { decode_add_endloop_insn(&pkt->insn[pkt->num_insns++], 1); } else if (has_loop0) { decode_add_endloop_insn(&pkt->insn[pkt->num_insns++], 0); } } decode_apply_extenders(pkt); if (!disas_only) { decode_remove_extenders(pkt); if (!decode_set_slot_number(pkt)) { /* Invalid packet */ return 0; } } decode_fill_newvalue_regno(pkt); if (pkt->pkt_has_hvx) { mmvec_ext_decode_checks(pkt, disas_only); } if (!disas_only) { decode_shuffle_for_execution(pkt); decode_split_cmpjump(pkt); decode_set_insn_attr_fields(pkt); } return words_read; } /* Used for "-d in_asm" logging */ int disassemble_hexagon(uint32_t *words, int nwords, bfd_vma pc, GString *buf) { DisasContext ctx; Packet pkt; memset(&ctx, 0, sizeof(DisasContext)); ctx.pkt = &pkt; if (decode_packet(&ctx, nwords, words, &pkt, true) > 0) { snprint_a_pkt_disas(buf, &pkt, words, pc); return pkt.encod_pkt_size_in_bytes; } else { g_string_assign(buf, ""); return 0; } }