Example #1
0
static struct qinst *
vc4_find_cse(struct vc4_compile *c, struct hash_table *ht,
             struct qinst *inst, uint32_t sf_count,
             uint32_t r4_count)
{
        if (inst->dst.file != QFILE_TEMP ||
            inst->op == QOP_MOV ||
            qir_get_op_nsrc(inst->op) > 4) {
                return NULL;
        }

        struct inst_key key;
        memset(&key, 0, sizeof(key));
        key.op = inst->op;
        memcpy(key.src, inst->src,
               qir_get_op_nsrc(inst->op) * sizeof(key.src[0]));
        if (qir_depends_on_flags(inst))
                key.implicit_arg_update_count = sf_count;
        if (qir_reads_r4(inst))
                key.implicit_arg_update_count = r4_count;

        uint32_t hash = _mesa_hash_data(&key, sizeof(key));
        struct hash_entry *entry =
                _mesa_hash_table_search_pre_hashed(ht, hash, &key);

        if (entry) {
                if (debug) {
                        fprintf(stderr, "CSE found match:\n");

                        fprintf(stderr, "  Original inst: ");
                        qir_dump_inst(c, entry->data);
                        fprintf(stderr, "\n");

                        fprintf(stderr, "  Our inst:      ");
                        qir_dump_inst(c, inst);
                        fprintf(stderr, "\n");
                }

                return entry->data;
        }

        struct inst_key *alloc_key = ralloc(ht, struct inst_key);
        if (!alloc_key)
                return NULL;
        memcpy(alloc_key, &key, sizeof(*alloc_key));
        _mesa_hash_table_insert_pre_hashed(ht, hash, alloc_key, inst);

        if (debug) {
                fprintf(stderr, "Added to CSE HT: ");
                qir_dump_inst(c, inst);
                fprintf(stderr, "\n");
        }

        return NULL;
}
Example #2
0
static void
dump_to(struct vc4_compile *c, struct qinst *inst)
{
        if (!debug)
                return;

        fprintf(stderr, "to: ");
        qir_dump_inst(c, inst);
        fprintf(stderr, "\n");
}
Example #3
0
static void
dump_from(struct vc4_compile *c, struct qinst *inst, const char *type)
{
        if (!debug)
                return;

        fprintf(stderr, "optimizing %s: ", type);
        qir_dump_inst(c, inst);
        fprintf(stderr, "\n");
}
Example #4
0
static void
dce(struct vc4_compile *c, struct qinst *inst)
{
        if (debug) {
                fprintf(stderr, "Removing: ");
                qir_dump_inst(c, inst);
                fprintf(stderr, "\n");
        }
        qir_remove_instruction(inst);
}
Example #5
0
bool
qir_opt_cse(struct vc4_compile *c)
{
        bool progress = false;
        uint32_t sf_count = 0, r4_count = 0;

        struct hash_table *ht = _mesa_hash_table_create(NULL, NULL,
                                                        inst_key_equals);
        if (!ht)
                return false;

        list_for_each_entry(struct qinst, inst, &c->instructions, link) {
                if (qir_has_side_effects(c, inst) ||
                    qir_has_side_effect_reads(c, inst) ||
                    inst->op == QOP_TLB_COLOR_READ) {
                        continue;
                }

                if (inst->sf) {
                        sf_count++;
                } else {
                        struct qinst *cse = vc4_find_cse(c, ht, inst,
                                                         sf_count, r4_count);
                        if (cse) {
                                inst->src[0] = cse->dst;
                                for (int i = 1; i < qir_get_op_nsrc(inst->op);
                                     i++)
                                        inst->src[i] = c->undef;
                                inst->op = QOP_MOV;
                                progress = true;

                                if (debug) {
                                        fprintf(stderr, "  Turned into:   ");
                                        qir_dump_inst(c, inst);
                                        fprintf(stderr, "\n");
                                }
                        }
                }

                if (qir_writes_r4(inst))
                        r4_count++;
        }

        ralloc_free(ht);

        return progress;
}
Example #6
0
bool
qir_opt_dead_code(struct vc4_compile *c)
{
        bool progress = false;
        bool debug = false;
        bool *used = calloc(c->num_temps, sizeof(bool));

        struct simple_node *node, *t;
        for (node = c->instructions.prev, t = node->prev;
             &c->instructions != node;
             node = t, t = t->prev) {
                struct qinst *inst = (struct qinst *)node;

                if (inst->dst.file == QFILE_TEMP &&
                    !used[inst->dst.index] &&
                    !qir_has_side_effects(inst)) {
                        if (debug) {
                                fprintf(stderr, "Removing: ");
                                qir_dump_inst(inst);
                                fprintf(stderr, "\n");
                        }
                        qir_remove_instruction(inst);
                        progress = true;
                        continue;
                }

                for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
                        if (inst->src[i].file == QFILE_TEMP)
                                used[inst->src[i].index] = true;
                }
        }

        free(used);

        return progress;
}
Example #7
0
void
vc4_generate_code(struct vc4_context *vc4, struct vc4_compile *c)
{
        struct qpu_reg *temp_registers = vc4_register_allocate(vc4, c);
        bool discard = false;
        uint32_t inputs_remaining = c->num_inputs;
        uint32_t vpm_read_fifo_count = 0;
        uint32_t vpm_read_offset = 0;
        int last_vpm_read_index = -1;
        /* Map from the QIR ops enum order to QPU unpack bits. */
        static const uint32_t unpack_map[] = {
                QPU_UNPACK_8A,
                QPU_UNPACK_8B,
                QPU_UNPACK_8C,
                QPU_UNPACK_8D,
                QPU_UNPACK_16A_TO_F32,
                QPU_UNPACK_16B_TO_F32,
        };

        list_inithead(&c->qpu_inst_list);

        switch (c->stage) {
        case QSTAGE_VERT:
        case QSTAGE_COORD:
                /* There's a 4-entry FIFO for VPMVCD reads, each of which can
                 * load up to 16 dwords (4 vec4s) per vertex.
                 */
                while (inputs_remaining) {
                        uint32_t num_entries = MIN2(inputs_remaining, 16);
                        queue(c, qpu_load_imm_ui(qpu_vrsetup(),
                                                 vpm_read_offset |
                                                 0x00001a00 |
                                                 ((num_entries & 0xf) << 20)));
                        inputs_remaining -= num_entries;
                        vpm_read_offset += num_entries;
                        vpm_read_fifo_count++;
                }
                assert(vpm_read_fifo_count <= 4);

                queue(c, qpu_load_imm_ui(qpu_vwsetup(), 0x00001a00));
                break;
        case QSTAGE_FRAG:
                break;
        }

        list_for_each_entry(struct qinst, qinst, &c->instructions, link) {
#if 0
                fprintf(stderr, "translating qinst to qpu: ");
                qir_dump_inst(qinst);
                fprintf(stderr, "\n");
#endif

                static const struct {
                        uint32_t op;
                } translate[] = {
#define A(name) [QOP_##name] = {QPU_A_##name}
#define M(name) [QOP_##name] = {QPU_M_##name}
                        A(FADD),
                        A(FSUB),
                        A(FMIN),
                        A(FMAX),
                        A(FMINABS),
                        A(FMAXABS),
                        A(FTOI),
                        A(ITOF),
                        A(ADD),
                        A(SUB),
                        A(SHL),
                        A(SHR),
                        A(ASR),
                        A(MIN),
                        A(MAX),
                        A(AND),
                        A(OR),
                        A(XOR),
                        A(NOT),

                        M(FMUL),
                        M(MUL24),
                };

                struct qpu_reg src[4];
                for (int i = 0; i < qir_get_op_nsrc(qinst->op); i++) {
                        int index = qinst->src[i].index;
                        switch (qinst->src[i].file) {
                        case QFILE_NULL:
                                src[i] = qpu_rn(0);
                                break;
                        case QFILE_TEMP:
                                src[i] = temp_registers[index];
                                break;
                        case QFILE_UNIF:
                                src[i] = qpu_unif();
                                break;
                        case QFILE_VARY:
                                src[i] = qpu_vary();
                                break;
                        case QFILE_SMALL_IMM:
                                src[i].mux = QPU_MUX_SMALL_IMM;
                                src[i].addr = qpu_encode_small_immediate(qinst->src[i].index);
                                /* This should only have returned a valid
                                 * small immediate field, not ~0 for failure.
                                 */
                                assert(src[i].addr <= 47);
                                break;
                        case QFILE_VPM:
                                assert((int)qinst->src[i].index >=
                                       last_vpm_read_index);
                                (void)last_vpm_read_index;
                                last_vpm_read_index = qinst->src[i].index;
                                src[i] = qpu_ra(QPU_R_VPM);
                                break;
                        }
                }

                struct qpu_reg dst;
                switch (qinst->dst.file) {
                case QFILE_NULL:
                        dst = qpu_ra(QPU_W_NOP);
                        break;
                case QFILE_TEMP:
                        dst = temp_registers[qinst->dst.index];
                        break;
                case QFILE_VPM:
                        dst = qpu_ra(QPU_W_VPM);
                        break;
                case QFILE_VARY:
                case QFILE_UNIF:
                case QFILE_SMALL_IMM:
                        assert(!"not reached");
                        break;
                }

                switch (qinst->op) {
                case QOP_MOV:
                        /* Skip emitting the MOV if it's a no-op. */
                        if (dst.mux == QPU_MUX_A || dst.mux == QPU_MUX_B ||
                            dst.mux != src[0].mux || dst.addr != src[0].addr) {
                                queue(c, qpu_a_MOV(dst, src[0]));
                        }
                        break;

                case QOP_SEL_X_0_ZS:
                case QOP_SEL_X_0_ZC:
                case QOP_SEL_X_0_NS:
                case QOP_SEL_X_0_NC:
                case QOP_SEL_X_0_CS:
                case QOP_SEL_X_0_CC:
                        queue(c, qpu_a_MOV(dst, src[0]));
                        set_last_cond_add(c, qinst->op - QOP_SEL_X_0_ZS +
                                          QPU_COND_ZS);

                        queue(c, qpu_a_XOR(dst, qpu_r0(), qpu_r0()));
                        set_last_cond_add(c, ((qinst->op - QOP_SEL_X_0_ZS) ^
                                              1) + QPU_COND_ZS);
                        break;

                case QOP_SEL_X_Y_ZS:
                case QOP_SEL_X_Y_ZC:
                case QOP_SEL_X_Y_NS:
                case QOP_SEL_X_Y_NC:
                case QOP_SEL_X_Y_CS:
                case QOP_SEL_X_Y_CC:
                        queue(c, qpu_a_MOV(dst, src[0]));
                        set_last_cond_add(c, qinst->op - QOP_SEL_X_Y_ZS +
                                          QPU_COND_ZS);

                        queue(c, qpu_a_MOV(dst, src[1]));
                        set_last_cond_add(c, ((qinst->op - QOP_SEL_X_Y_ZS) ^
                                              1) + QPU_COND_ZS);

                        break;

                case QOP_RCP:
                case QOP_RSQ:
                case QOP_EXP2:
                case QOP_LOG2:
                        switch (qinst->op) {
                        case QOP_RCP:
                                queue(c, qpu_a_MOV(qpu_rb(QPU_W_SFU_RECIP),
                                                   src[0]));
                                break;
                        case QOP_RSQ:
                                queue(c, qpu_a_MOV(qpu_rb(QPU_W_SFU_RECIPSQRT),
                                                   src[0]));
                                break;
                        case QOP_EXP2:
                                queue(c, qpu_a_MOV(qpu_rb(QPU_W_SFU_EXP),
                                                   src[0]));
                                break;
                        case QOP_LOG2:
                                queue(c, qpu_a_MOV(qpu_rb(QPU_W_SFU_LOG),
                                                   src[0]));
                                break;
                        default:
                                abort();
                        }

                        if (dst.mux != QPU_MUX_R4)
                                queue(c, qpu_a_MOV(dst, qpu_r4()));

                        break;

                case QOP_PACK_8888_F:
                        queue(c, qpu_m_MOV(dst, src[0]));
                        *last_inst(c) |= QPU_PM;
                        *last_inst(c) |= QPU_SET_FIELD(QPU_PACK_MUL_8888,
                                                       QPU_PACK);
                        break;

                case QOP_PACK_8A_F:
                case QOP_PACK_8B_F:
                case QOP_PACK_8C_F:
                case QOP_PACK_8D_F:
                        queue(c,
                              qpu_m_MOV(dst, src[0]) |
                              QPU_PM |
                              QPU_SET_FIELD(QPU_PACK_MUL_8A +
                                            qinst->op - QOP_PACK_8A_F,
                                            QPU_PACK));
                        break;

                case QOP_FRAG_X:
                        queue(c, qpu_a_ITOF(dst,
                                            qpu_ra(QPU_R_XY_PIXEL_COORD)));
                        break;

                case QOP_FRAG_Y:
                        queue(c, qpu_a_ITOF(dst,
                                            qpu_rb(QPU_R_XY_PIXEL_COORD)));
                        break;

                case QOP_FRAG_REV_FLAG:
                        queue(c, qpu_a_ITOF(dst,
                                            qpu_rb(QPU_R_MS_REV_FLAGS)));
                        break;

                case QOP_FRAG_Z:
                case QOP_FRAG_W:
                        /* QOP_FRAG_Z/W don't emit instructions, just allocate
                         * the register to the Z/W payload.
                         */
                        break;

                case QOP_TLB_DISCARD_SETUP:
                        discard = true;
                        queue(c, qpu_a_MOV(src[0], src[0]));
                        *last_inst(c) |= QPU_SF;
                        break;

                case QOP_TLB_STENCIL_SETUP:
                        queue(c, qpu_a_MOV(qpu_ra(QPU_W_TLB_STENCIL_SETUP), src[0]));
                        break;

                case QOP_TLB_Z_WRITE:
                        queue(c, qpu_a_MOV(qpu_ra(QPU_W_TLB_Z), src[0]));
                        if (discard) {
                                set_last_cond_add(c, QPU_COND_ZS);
                        }
                        break;

                case QOP_TLB_COLOR_READ:
                        queue(c, qpu_NOP());
                        *last_inst(c) = qpu_set_sig(*last_inst(c),
                                                    QPU_SIG_COLOR_LOAD);

                        if (dst.mux != QPU_MUX_R4)
                                queue(c, qpu_a_MOV(dst, qpu_r4()));
                        break;

                case QOP_TLB_COLOR_WRITE:
                        queue(c, qpu_a_MOV(qpu_tlbc(), src[0]));
                        if (discard) {
                                set_last_cond_add(c, QPU_COND_ZS);
                        }
                        break;

                case QOP_VARY_ADD_C:
                        queue(c, qpu_a_FADD(dst, src[0], qpu_r5()));
                        break;

                case QOP_TEX_S:
                case QOP_TEX_T:
                case QOP_TEX_R:
                case QOP_TEX_B:
                        queue(c, qpu_a_MOV(qpu_rb(QPU_W_TMU0_S +
                                                  (qinst->op - QOP_TEX_S)),
                                           src[0]));
                        break;

                case QOP_TEX_DIRECT:
                        fixup_raddr_conflict(c, dst, &src[0], &src[1]);
                        queue(c, qpu_a_ADD(qpu_rb(QPU_W_TMU0_S), src[0], src[1]));
                        break;

                case QOP_TEX_RESULT:
                        queue(c, qpu_NOP());
                        *last_inst(c) = qpu_set_sig(*last_inst(c),
                                                    QPU_SIG_LOAD_TMU0);
                        if (dst.mux != QPU_MUX_R4)
                                queue(c, qpu_a_MOV(dst, qpu_r4()));
                        break;

                case QOP_UNPACK_8A_F:
                case QOP_UNPACK_8B_F:
                case QOP_UNPACK_8C_F:
                case QOP_UNPACK_8D_F:
                case QOP_UNPACK_16A_F:
                case QOP_UNPACK_16B_F: {
                        if (src[0].mux == QPU_MUX_R4) {
                                queue(c, qpu_a_MOV(dst, src[0]));
                                *last_inst(c) |= QPU_PM;
                                *last_inst(c) |= QPU_SET_FIELD(QPU_UNPACK_8A +
                                                               (qinst->op -
                                                                QOP_UNPACK_8A_F),
                                                               QPU_UNPACK);
                        } else {
                                assert(src[0].mux == QPU_MUX_A);

                                /* Since we're setting the pack bits, if the
                                 * destination is in A it would get re-packed.
                                 */
                                queue(c, qpu_a_FMAX((dst.mux == QPU_MUX_A ?
                                                     qpu_rb(31) : dst),
                                                    src[0], src[0]));
                                *last_inst(c) |=
                                        QPU_SET_FIELD(unpack_map[qinst->op -
                                                                 QOP_UNPACK_8A_F],
                                                      QPU_UNPACK);

                                if (dst.mux == QPU_MUX_A) {
                                        queue(c, qpu_a_MOV(dst, qpu_rb(31)));
                                }
                        }
                }
                        break;

                case QOP_UNPACK_8A_I:
                case QOP_UNPACK_8B_I:
                case QOP_UNPACK_8C_I:
                case QOP_UNPACK_8D_I:
                case QOP_UNPACK_16A_I:
                case QOP_UNPACK_16B_I: {
                        assert(src[0].mux == QPU_MUX_A);

                        /* Since we're setting the pack bits, if the
                         * destination is in A it would get re-packed.
                         */
                        queue(c, qpu_a_MOV((dst.mux == QPU_MUX_A ?
                                            qpu_rb(31) : dst), src[0]));
                        *last_inst(c) |= QPU_SET_FIELD(unpack_map[qinst->op -
                                                                  QOP_UNPACK_8A_I],
                                                       QPU_UNPACK);

                        if (dst.mux == QPU_MUX_A) {
                                queue(c, qpu_a_MOV(dst, qpu_rb(31)));
                        }
                }
                        break;

                default:
                        assert(qinst->op < ARRAY_SIZE(translate));
                        assert(translate[qinst->op].op != 0); /* NOPs */

                        /* If we have only one source, put it in the second
                         * argument slot as well so that we don't take up
                         * another raddr just to get unused data.
                         */
                        if (qir_get_op_nsrc(qinst->op) == 1)
                                src[1] = src[0];

                        fixup_raddr_conflict(c, dst, &src[0], &src[1]);

                        if (qir_is_mul(qinst)) {
                                queue(c, qpu_m_alu2(translate[qinst->op].op,
                                                    dst,
                                                    src[0], src[1]));
                                if (qinst->dst.pack) {
                                        *last_inst(c) |= QPU_PM;
                                        *last_inst(c) |= QPU_SET_FIELD(qinst->dst.pack,
                                                                       QPU_PACK);
                                }
                        } else {
                                queue(c, qpu_a_alu2(translate[qinst->op].op,
                                                    dst,
                                                    src[0], src[1]));
                                if (qinst->dst.pack) {
                                        assert(dst.mux == QPU_MUX_A);
                                        *last_inst(c) |= QPU_SET_FIELD(qinst->dst.pack,
                                                                       QPU_PACK);
                                }
                        }

                        break;
                }

                if (qinst->sf) {
                        assert(!qir_is_multi_instruction(qinst));
                        *last_inst(c) |= QPU_SF;
                }
        }

        qpu_schedule_instructions(c);

        /* thread end can't have VPM write or read */
        if (QPU_GET_FIELD(c->qpu_insts[c->qpu_inst_count - 1],
                          QPU_WADDR_ADD) == QPU_W_VPM ||
            QPU_GET_FIELD(c->qpu_insts[c->qpu_inst_count - 1],
                          QPU_WADDR_MUL) == QPU_W_VPM ||
            QPU_GET_FIELD(c->qpu_insts[c->qpu_inst_count - 1],
                          QPU_RADDR_A) == QPU_R_VPM ||
            QPU_GET_FIELD(c->qpu_insts[c->qpu_inst_count - 1],
                          QPU_RADDR_B) == QPU_R_VPM) {
                qpu_serialize_one_inst(c, qpu_NOP());
        }

        /* thread end can't have uniform read */
        if (QPU_GET_FIELD(c->qpu_insts[c->qpu_inst_count - 1],
                          QPU_RADDR_A) == QPU_R_UNIF ||
            QPU_GET_FIELD(c->qpu_insts[c->qpu_inst_count - 1],
                          QPU_RADDR_B) == QPU_R_UNIF) {
                qpu_serialize_one_inst(c, qpu_NOP());
        }

        /* thread end can't have TLB operations */
        if (qpu_inst_is_tlb(c->qpu_insts[c->qpu_inst_count - 1]))
                qpu_serialize_one_inst(c, qpu_NOP());

        c->qpu_insts[c->qpu_inst_count - 1] =
                qpu_set_sig(c->qpu_insts[c->qpu_inst_count - 1],
                            QPU_SIG_PROG_END);
        qpu_serialize_one_inst(c, qpu_NOP());
        qpu_serialize_one_inst(c, qpu_NOP());

        switch (c->stage) {
        case QSTAGE_VERT:
        case QSTAGE_COORD:
                break;
        case QSTAGE_FRAG:
                c->qpu_insts[c->qpu_inst_count - 1] =
                        qpu_set_sig(c->qpu_insts[c->qpu_inst_count - 1],
                                    QPU_SIG_SCOREBOARD_UNLOCK);
                break;
        }

        if (vc4_debug & VC4_DEBUG_QPU)
                vc4_dump_program(c);

        vc4_qpu_validate(c->qpu_insts, c->qpu_inst_count);

        free(temp_registers);
}
Example #8
0
static bool
try_copy_prop(struct vc4_compile *c, struct qinst *inst, struct qinst **movs)
{
        bool debug = false;
        bool progress = false;

	for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
                if (inst->src[i].file != QFILE_TEMP)
                        continue;

                /* We have two ways of finding MOVs we can copy propagate
                 * from.  One is if it's an SSA def: then we can reuse it from
                 * any block in the program, as long as its source is also an
                 * SSA def.  Alternatively, if it's in the "movs" array
                 * tracked within the block, then we know the sources for it
                 * haven't been changed since we saw the instruction within
                 * our block.
                 */
                struct qinst *mov = movs[inst->src[i].index];
                if (!mov) {
                        if (!is_copy_mov(c->defs[inst->src[i].index]))
                                continue;
                        mov = c->defs[inst->src[i].index];

                        if (mov->src[0].file == QFILE_TEMP &&
                            !c->defs[mov->src[0].index])
                                continue;
                }

                /* Mul rotation's source needs to be in an r0-r3 accumulator,
                 * so no uniforms or regfile-a/r4 unpacking allowed.
                 */
                if (inst->op == QOP_ROT_MUL &&
                    (mov->src[0].file != QFILE_TEMP ||
                     mov->src[0].pack))
                        continue;

                uint8_t unpack;
                if (mov->src[0].pack) {
                        /* Make sure that the meaning of the unpack
                         * would be the same between the two
                         * instructions.
                         */
                        if (qir_is_float_input(inst) !=
                            qir_is_float_input(mov)) {
                                continue;
                        }

                        /* There's only one unpack field, so make sure
                         * this instruction doesn't already use it.
                         */
                        bool already_has_unpack = false;
                        for (int j = 0; j < qir_get_op_nsrc(inst->op); j++) {
                                if (inst->src[j].pack)
                                        already_has_unpack = true;
                        }
                        if (already_has_unpack)
                                continue;

                        /* A destination pack requires the PM bit to
                         * be set to a specific value already, which
                         * may be different from ours.
                         */
                        if (inst->dst.pack)
                                continue;

                        unpack = mov->src[0].pack;
                } else {
                        unpack = inst->src[i].pack;
                }

                if (debug) {
                        fprintf(stderr, "Copy propagate: ");
                        qir_dump_inst(c, inst);
                        fprintf(stderr, "\n");
                }

                inst->src[i] = mov->src[0];
                inst->src[i].pack = unpack;

                if (debug) {
                        fprintf(stderr, "to: ");
                        qir_dump_inst(c, inst);
                        fprintf(stderr, "\n");
                }

                progress = true;
        }

        return progress;
}
Example #9
0
bool
qir_opt_dead_code(struct vc4_compile *c)
{
        bool progress = false;
        bool *used = calloc(c->num_temps, sizeof(bool));
        bool sf_used = false;
        /* Whether we're eliminating texture setup currently. */
        bool dce_tex = false;

        struct simple_node *node, *t;
        for (node = c->instructions.prev, t = node->prev;
             &c->instructions != node;
             node = t, t = t->prev) {
                struct qinst *inst = (struct qinst *)node;

                if (inst->dst.file == QFILE_TEMP &&
                    !used[inst->dst.index] &&
                    !inst->sf &&
                    (!qir_has_side_effects(c, inst) ||
                     inst->op == QOP_TEX_RESULT) &&
                    !has_nonremovable_reads(c, inst)) {
                        if (inst->op == QOP_TEX_RESULT) {
                                dce_tex = true;
                                c->num_texture_samples--;
                        }

                        for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
                                if (inst->src[i].file != QFILE_VPM)
                                        continue;
                                uint32_t attr = inst->src[i].index / 4;
                                uint32_t offset = (inst->src[i].index % 4) * 4;

                                if (c->vattr_sizes[attr] == offset + 4) {
                                        c->num_inputs--;
                                        c->vattr_sizes[attr] -= 4;
                                }
                        }

                        dce(c, inst);
                        progress = true;
                        continue;
                }

                if (qir_depends_on_flags(inst))
                        sf_used = true;
                if (inst->sf) {
                        if (!sf_used) {
                                if (debug) {
                                        fprintf(stderr, "Removing SF on: ");
                                        qir_dump_inst(c, inst);
                                        fprintf(stderr, "\n");
                                }

                                inst->sf = false;
                                progress = true;
                        }
                        sf_used = false;
                }

                if (inst->op == QOP_TEX_RESULT)
                        dce_tex = false;

                if (dce_tex && (inst->op == QOP_TEX_S ||
                                inst->op == QOP_TEX_T ||
                                inst->op == QOP_TEX_R ||
                                inst->op == QOP_TEX_B ||
                                inst->op == QOP_TEX_DIRECT)) {
                        dce(c, inst);
                        progress = true;
                        continue;
                }

                for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
                        if (inst->src[i].file == QFILE_TEMP)
                                used[inst->src[i].index] = true;
                }
        }

        free(used);

        return progress;
}
bool
qir_opt_small_immediates(struct vc4_compile *c)
{
        bool progress = false;

        qir_for_each_inst_inorder(inst, c) {
                /* The small immediate value sits in the raddr B field, so we
                 * can't have 2 small immediates in one instruction (unless
                 * they're the same value, but that should be optimized away
                 * elsewhere).
                 */
                bool uses_small_imm = false;
                for (int i = 0; i < qir_get_nsrc(inst); i++) {
                        if (inst->src[i].file == QFILE_SMALL_IMM)
                                uses_small_imm = true;
                }
                if (uses_small_imm)
                        continue;

                /* Don't propagate small immediates into the top-end bounds
                 * checking for indirect UBO loads.  The kernel doesn't parse
                 * small immediates and rejects the shader in this case.  UBO
                 * loads are much more expensive than the uniform load, and
                 * indirect UBO regions are usually much larger than a small
                 * immediate, so it's not worth updating the kernel to allow
                 * optimizing it.
                 */
                if (inst->op == QOP_MIN_NOIMM)
                        continue;

                for (int i = 0; i < qir_get_nsrc(inst); i++) {
                        struct qreg src = qir_follow_movs(c, inst->src[i]);

                        if (src.file != QFILE_UNIF ||
                            src.pack ||
                            c->uniform_contents[src.index] !=
                            QUNIFORM_CONSTANT) {
                                continue;
                        }

                        if (qir_is_tex(inst) &&
                            i == qir_get_tex_uniform_src(inst)) {
                                /* No turning the implicit uniform read into
                                 * an immediate.
                                 */
                                continue;
                        }

                        uint32_t imm = c->uniform_data[src.index];
                        uint32_t small_imm = qpu_encode_small_immediate(imm);
                        if (small_imm == ~0)
                                continue;

                        if (debug) {
                                fprintf(stderr, "opt_small_immediate() from: ");
                                qir_dump_inst(c, inst);
                                fprintf(stderr, "\n");
                        }
                        inst->src[i].file = QFILE_SMALL_IMM;
                        inst->src[i].index = imm;
                        if (debug) {
                                fprintf(stderr, "to: ");
                                qir_dump_inst(c, inst);
                                fprintf(stderr, "\n");
                        }
                        progress = true;
                        break;
                }
        }