xref: /xsrc/external/mit/MesaLib/dist/src/panfrost/midgard/disassemble.c

/* Author(s):
 *   Connor Abbott
 *   Alyssa Rosenzweig
 *
 * Copyright (c) 2013 Connor Abbott (connor@abbott.cx)
 * Copyright (c) 2018 Alyssa Rosenzweig (alyssa@rosenzweig.io)
 * Copyright (C) 2019-2020 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 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 <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <assert.h>
#include <inttypes.h>
#include <ctype.h>
#include <string.h>
#include "midgard.h"
#include "midgard_ops.h"
#include "midgard_quirks.h"
#include "disassemble.h"
#include "helpers.h"
#include "util/bitscan.h"
#include "util/half_float.h"
#include "util/u_math.h"

#define DEFINE_CASE(define, str) case define: { fprintf(fp, str); break; }

/* These are not mapped to hardware values, they just represent the possible
 * implicit arg modifiers that some midgard opcodes have, which can be decoded
 * from the opcodes via midgard_{alu,ldst,tex}_special_arg_mod() */
typedef enum {
        midgard_arg_mod_none = 0,
        midgard_arg_mod_inv,
        midgard_arg_mod_x2,
} midgard_special_arg_mod;

typedef struct {
        unsigned *midg_tags;
        struct midgard_disasm_stats midg_stats;

        /* For static analysis to ensure all registers are written at least once before
         * use along the source code path (TODO: does this break done for complex CF?)
         */

        uint16_t midg_ever_written;
} disassemble_context;

/* Transform an expanded writemask (duplicated 8-bit format) into its condensed
 * form (one bit per component) */

static inline unsigned
condense_writemask(unsigned expanded_mask,
                   unsigned bits_per_component)
{
        if (bits_per_component == 8) {
                /* Duplicate every bit to go from 8 to 16-channel wrmask */
                unsigned omask = 0;

                for (unsigned i = 0; i < 8; ++i) {
                        if (expanded_mask & (1 << i))
                                omask |= (3 << (2 * i));
                }

                return omask;
        }

        unsigned slots_per_component = bits_per_component / 16;
        unsigned max_comp = (16 * 8) / bits_per_component;
        unsigned condensed_mask = 0;

        for (unsigned i = 0; i < max_comp; i++) {
                if (expanded_mask & (1 << (i * slots_per_component)))
                        condensed_mask |= (1 << i);
        }

        return condensed_mask;
}

static bool
print_alu_opcode(FILE *fp, midgard_alu_op op)
{
        if (alu_opcode_props[op].name)
                fprintf(fp, "%s", alu_opcode_props[op].name);
        else
                fprintf(fp, "alu_op_%02X", op);

        /* For constant analysis */
        return midgard_is_integer_op(op);
}

static void
print_ld_st_opcode(FILE *fp, midgard_load_store_op op)
{
        if (load_store_opcode_props[op].name)
                fprintf(fp, "%s", load_store_opcode_props[op].name);
        else
                fprintf(fp, "ldst_op_%02X", op);
}

static void
validate_sampler_type(enum mali_texture_op op, enum mali_sampler_type sampler_type)
{
        if (op == midgard_tex_op_mov || op == midgard_tex_op_barrier)
                assert(sampler_type == 0);
        else
                assert(sampler_type > 0);
}

static void
validate_expand_mode(midgard_src_expand_mode expand_mode,
                     midgard_reg_mode reg_mode)
{
        switch (expand_mode) {
        case midgard_src_passthrough:
                break;

        case midgard_src_rep_low:
                assert(reg_mode == midgard_reg_mode_8 ||
                       reg_mode == midgard_reg_mode_16);
                break;

        case midgard_src_rep_high:
                assert(reg_mode == midgard_reg_mode_8 ||
                       reg_mode == midgard_reg_mode_16);
                break;

        case midgard_src_swap:
                assert(reg_mode == midgard_reg_mode_8 ||
                       reg_mode == midgard_reg_mode_16);
                break;

        case midgard_src_expand_low:
                assert(reg_mode != midgard_reg_mode_8);
                break;

        case midgard_src_expand_high:
                assert(reg_mode != midgard_reg_mode_8);
                break;

        case midgard_src_expand_low_swap:
                assert(reg_mode == midgard_reg_mode_16);
                break;

        case midgard_src_expand_high_swap:
                assert(reg_mode == midgard_reg_mode_16);
                break;

        default:
                unreachable("Invalid expand mode");
                break;
        }
}

static void
print_alu_reg(disassemble_context *ctx, FILE *fp, unsigned reg, bool is_write)
{
        unsigned uniform_reg = 23 - reg;
        bool is_uniform = false;

        /* For r8-r15, it could be a work or uniform. We distinguish based on
         * the fact work registers are ALWAYS written before use, but uniform
         * registers are NEVER written before use. */

        if ((reg >= 8 && reg < 16) && !(ctx->midg_ever_written & (1 << reg)))
                is_uniform = true;

        /* r16-r23 are always uniform */

        if (reg >= 16 && reg <= 23)
                is_uniform = true;

        /* Update the uniform count appropriately */

        if (is_uniform)
                ctx->midg_stats.uniform_count =
                        MAX2(uniform_reg + 1, ctx->midg_stats.uniform_count);

        if (reg == REGISTER_UNUSED || reg == REGISTER_UNUSED + 1)
                fprintf(fp, "TMP%u", reg - REGISTER_UNUSED);
        else if (reg == REGISTER_TEXTURE_BASE || reg == REGISTER_TEXTURE_BASE + 1)
                fprintf(fp, "%s%u", is_write ? "AT" : "TA",  reg - REGISTER_TEXTURE_BASE);
        else if (reg == REGISTER_LDST_BASE || reg == REGISTER_LDST_BASE + 1)
                fprintf(fp, "AL%u", reg - REGISTER_LDST_BASE);
        else if (is_uniform)
                fprintf(fp, "U%u", uniform_reg);
        else if (reg == 31 && !is_write)
                fprintf(fp, "PC_SP");
        else
                fprintf(fp, "R%u", reg);
}

static void
print_ldst_write_reg(FILE *fp, unsigned reg)
{
        switch (reg) {
        case 26:
        case 27:
                fprintf(fp, "AL%u", reg - REGISTER_LDST_BASE);
                break;
        case 28:
        case 29:
                fprintf(fp, "AT%u", reg - REGISTER_TEXTURE_BASE);
                break;
        case 31:
                fprintf(fp, "PC_SP");
                break;
        default:
                fprintf(fp, "R%d", reg);
                break;
        }
}

static void
print_ldst_read_reg(FILE *fp, unsigned reg)
{
        switch (reg) {
        case 0:
        case 1:
                fprintf(fp, "AL%u", reg);
                break;
        case 2:
                fprintf(fp, "PC_SP");
                break;
        case 3:
                fprintf(fp, "LOCAL_STORAGE_PTR");
                break;
        case 4:
                fprintf(fp, "LOCAL_THREAD_ID");
                break;
        case 5:
                fprintf(fp, "GROUP_ID");
                break;
        case 6:
                fprintf(fp, "GLOBAL_THREAD_ID");
                break;
        case 7:
                fprintf(fp, "0");
                break;
        default:
                unreachable("Invalid load/store register read");
        }
}

static void
print_tex_reg(FILE *fp, unsigned reg, bool is_write)
{
        char *str = is_write ? "TA" : "AT";
        int select = reg & 1;

        switch (reg) {
        case 0:
        case 1:
                fprintf(fp, "R%d", select);
                break;
        case 26:
        case 27:
                fprintf(fp, "AL%d", select);
                break;
        case 28:
        case 29:
                fprintf(fp, "%s%d", str, select);
                break;
        default:
                unreachable("Invalid texture register");
        }
}


static char *outmod_names_float[4] = {
        "",
        ".clamp_0_inf",
        ".clamp_m1_1",
        ".clamp_0_1"
};

static char *outmod_names_int[4] = {
        ".ssat",
        ".usat",
        ".keeplo",
        ".keephi"
};

static char *srcmod_names_int[4] = {
        ".sext",
        ".zext",
        ".replicate",
        ".lshift",
};

static char *argmod_names[3] = {
        "",
        ".inv",
        ".x2",
};

static char *index_format_names[4] = {
        "",
        ".u64",
        ".u32",
        ".s32"
};

static void
print_outmod(FILE *fp, unsigned outmod, bool is_int)
{
        fprintf(fp, "%s", is_int ? outmod_names_int[outmod] :
                outmod_names_float[outmod]);
}

static void
print_alu_outmod(FILE *fp, unsigned outmod, bool is_int, bool half)
{
        if (is_int && !half) {
                assert(outmod == midgard_outmod_keeplo);
                return;
        }

        if (!is_int && half)
                fprintf(fp, ".shrink");

        print_outmod(fp, outmod, is_int);
}

/* arg == 0 (dest), arg == 1 (src1), arg == 2 (src2) */
static midgard_special_arg_mod
midgard_alu_special_arg_mod(midgard_alu_op op, unsigned arg) {
        midgard_special_arg_mod mod = midgard_arg_mod_none;

        switch (op) {
        case midgard_alu_op_ishladd:
        case midgard_alu_op_ishlsub:
                if (arg == 1) mod = midgard_arg_mod_x2;
                break;

        default:
                break;
        }

        return mod;
}

static void
print_quad_word(FILE *fp, uint32_t *words, unsigned tabs)
{
        unsigned i;

        for (i = 0; i < 4; i++)
                fprintf(fp, "0x%08X%s ", words[i], i == 3 ? "" : ",");

        fprintf(fp, "\n");
}

static const char components[16] = "xyzwefghijklmnop";

static int
bits_for_mode(midgard_reg_mode mode)
{
        switch (mode) {
        case midgard_reg_mode_8:
                return 8;
        case midgard_reg_mode_16:
                return 16;
        case midgard_reg_mode_32:
                return 32;
        case midgard_reg_mode_64:
                return 64;
        default:
                unreachable("Invalid reg mode");
                return 0;
        }
}

static int
bits_for_mode_halved(midgard_reg_mode mode, bool half)
{
        unsigned bits = bits_for_mode(mode);

        if (half)
                bits >>= 1;

        return bits;
}

static void
print_vec_selectors_64(FILE *fp, unsigned swizzle,
                       midgard_reg_mode reg_mode,
                       midgard_src_expand_mode expand_mode,
                       unsigned selector_offset, uint8_t mask)
{
        bool expands = INPUT_EXPANDS(expand_mode);

        unsigned comp_skip = expands ? 1 : 2;
        unsigned mask_bit = 0;
        for (unsigned i = selector_offset; i < 4; i += comp_skip, mask_bit += 4) {
                if (!(mask & (1 << mask_bit))) continue;

                unsigned a = (swizzle >> (i * 2)) & 3;

                if (INPUT_EXPANDS(expand_mode)) {
                        fprintf(fp, "%c", components[a]);
                        continue;
                }

                unsigned b = (swizzle >> ((i+1) * 2)) & 3;

                /* Normally we're adjacent, but if there's an issue,
                 * don't make it ambiguous */

                if (b == a + 1)
                        fprintf(fp, "%c", a >> 1 ? 'Y' : 'X');
                else
                        fprintf(fp, "[%c%c]", components[a], components[b]);
        }
}

static void
print_vec_selectors(FILE *fp, unsigned swizzle,
                    midgard_reg_mode reg_mode,
                    unsigned selector_offset, uint8_t mask,
                    unsigned *mask_offset)
{
        assert(reg_mode != midgard_reg_mode_64);

        unsigned mask_skip = MAX2(bits_for_mode(reg_mode) / 16, 1);

        bool is_vec16 = reg_mode == midgard_reg_mode_8;

        for (unsigned i = 0; i < 4; i++, *mask_offset += mask_skip) {
                if (!(mask & (1 << *mask_offset))) continue;

                unsigned c = (swizzle >> (i * 2)) & 3;

                /* Vec16 has two components per swizzle selector. */
                if (is_vec16)
                        c *= 2;

                c += selector_offset;

                fprintf(fp, "%c", components[c]);
                if (is_vec16)
                        fprintf(fp, "%c", components[c+1]);
        }
}

static void
print_vec_swizzle(FILE *fp, unsigned swizzle,
                  midgard_src_expand_mode expand,
                  midgard_reg_mode mode,
                  uint8_t mask)
{
        unsigned bits = bits_for_mode_halved(mode, INPUT_EXPANDS(expand));

        /* Swizzle selectors are divided in two halves that are always
         * mirrored, the only difference is the starting component offset.
         * The number represents an offset into the components[] array. */
        unsigned first_half = 0;
        unsigned second_half = (128 / bits) / 2; /* only used for 8 and 16-bit */

        switch (expand) {
        case midgard_src_passthrough:
                if (swizzle == 0xE4) return; /* identity swizzle */
                break;

        case midgard_src_expand_low:
                second_half /= 2;
                break;

        case midgard_src_expand_high:
                first_half = second_half;
                second_half += second_half / 2;
                break;

        /* The rest of the cases are only used for 8 and 16-bit */

        case midgard_src_rep_low:
                second_half = 0;
                break;

        case midgard_src_rep_high:
                first_half = second_half;
                break;

        case midgard_src_swap:
                first_half = second_half;
                second_half = 0;
                break;

        case midgard_src_expand_low_swap:
                first_half = second_half / 2;
                second_half = 0;
                break;

        case midgard_src_expand_high_swap:
                first_half = second_half + second_half / 2;
                break;

        default:
                unreachable("Invalid expand mode");
                break;
        }

        fprintf(fp, ".");

        /* Vec2 are weird so we use a separate function to simplify things. */
        if (mode == midgard_reg_mode_64) {
                print_vec_selectors_64(fp, swizzle, mode, expand, first_half, mask);
                return;
        }

        unsigned mask_offs = 0;
        print_vec_selectors(fp, swizzle, mode, first_half, mask, &mask_offs);
        if (mode == midgard_reg_mode_8 || mode == midgard_reg_mode_16)
                print_vec_selectors(fp, swizzle, mode, second_half, mask, &mask_offs);
}

static void
print_scalar_constant(FILE *fp, unsigned src_binary,
                      const midgard_constants *consts,
                      midgard_scalar_alu *alu)
{
        midgard_scalar_alu_src *src = (midgard_scalar_alu_src *)&src_binary;
        assert(consts != NULL);

        fprintf(fp, "#");
        mir_print_constant_component(fp, consts, src->component,
                                     src->full ?
                                     midgard_reg_mode_32 : midgard_reg_mode_16,
                                     false, src->mod, alu->op);
}

static void
print_vector_constants(FILE *fp, unsigned src_binary,
                       const midgard_constants *consts,
                       midgard_vector_alu *alu)
{
        midgard_vector_alu_src *src = (midgard_vector_alu_src *)&src_binary;
        bool expands = INPUT_EXPANDS(src->expand_mode);
        unsigned bits = bits_for_mode_halved(alu->reg_mode, expands);
        unsigned max_comp = (sizeof(*consts) * 8) / bits;
        unsigned comp_mask, num_comp = 0;

        assert(consts);
        assert(max_comp <= 16);

        comp_mask = effective_writemask(alu->op, condense_writemask(alu->mask, bits));
        num_comp = util_bitcount(comp_mask);

        fprintf(fp, "<");
        bool first = true;

	for (unsigned i = 0; i < max_comp; ++i) {
                if (!(comp_mask & (1 << i))) continue;

                unsigned c = (src->swizzle >> (i * 2)) & 3;

                if (bits == 16 && !expands) {
                        bool upper = i >= 4;

                        switch (src->expand_mode) {
                        case midgard_src_passthrough:
                                c += upper * 4;
                                break;
                        case midgard_src_rep_low:
                                break;
                        case midgard_src_rep_high:
                                c += 4;
                                break;
                        case midgard_src_swap:
                                c += !upper * 4;
                                break;
                        default:
                                unreachable("invalid expand mode");
                                break;
                        }
                } else if (bits == 32 && !expands) {
                        /* Implicitly ok */
                } else if (bits == 64 && !expands) {
                        /* Implicitly ok */
                } else if (bits == 8 && !expands) {
                        bool upper = i >= 8;

                        unsigned index = (i >> 1) & 3;
                        unsigned base = (src->swizzle >> (index * 2)) & 3;
                        c = base * 2;

                        switch (src->expand_mode) {
                        case midgard_src_passthrough:
                                c += upper * 8;
                                break;
                        case midgard_src_rep_low:
                                break;
                        case midgard_src_rep_high:
                                c += 8;
                                break;
                        case midgard_src_swap:
                                c += !upper * 8;
                                break;
                        default:
                                unreachable("invalid expand mode");
                                break;
                        }

                        /* We work on twos, actually */
                        if (i & 1)
                                c++;
                } else {
                        printf(" (%u)", src->expand_mode);
                }

                if (first)
                        first = false;
                else
                        fprintf(fp, ", ");

                mir_print_constant_component(fp, consts, c, alu->reg_mode,
                                             expands, src->mod, alu->op);
        }

        if (num_comp > 1)
                fprintf(fp, ">");
}

static void
print_srcmod(FILE *fp, bool is_int, bool expands, unsigned mod, bool scalar)
{
        /* Modifiers change meaning depending on the op's context */

        if (is_int) {
                if (expands)
                        fprintf(fp, "%s", srcmod_names_int[mod]);
        } else {
                if (mod & MIDGARD_FLOAT_MOD_ABS)
                        fprintf(fp, ".abs");
                if (mod & MIDGARD_FLOAT_MOD_NEG)
                        fprintf(fp, ".neg");
                if (expands)
                        fprintf(fp, ".widen");
        }
}

static void
print_vector_src(disassemble_context *ctx, FILE *fp, unsigned src_binary,
                 midgard_reg_mode mode, unsigned reg,
                 midgard_shrink_mode shrink_mode,
                 uint8_t src_mask, bool is_int,
                 midgard_special_arg_mod arg_mod)
{
        midgard_vector_alu_src *src = (midgard_vector_alu_src *)&src_binary;

        validate_expand_mode(src->expand_mode, mode);

        print_alu_reg(ctx, fp, reg, false);

        print_vec_swizzle(fp, src->swizzle, src->expand_mode, mode, src_mask);

        fprintf(fp, "%s", argmod_names[arg_mod]);

        print_srcmod(fp, is_int, INPUT_EXPANDS(src->expand_mode), src->mod, false);
}

static uint16_t
decode_vector_imm(unsigned src2_reg, unsigned imm)
{
        uint16_t ret;
        ret = src2_reg << 11;
        ret |= (imm & 0x7) << 8;
        ret |= (imm >> 3) & 0xFF;
        return ret;
}

static void
print_immediate(FILE *fp, uint16_t imm, bool is_instruction_int)
{
        if (is_instruction_int)
                fprintf(fp, "#%u", imm);
        else
                fprintf(fp, "#%g", _mesa_half_to_float(imm));
}

static void
update_dest(disassemble_context *ctx, unsigned reg)
{
        /* We should record writes as marking this as a work register. Store
         * the max register in work_count; we'll add one at the end */

        if (reg < 16) {
                ctx->midg_stats.work_count = MAX2(reg, ctx->midg_stats.work_count);
                ctx->midg_ever_written |= (1 << reg);
        }
}

static void
print_dest(disassemble_context *ctx, FILE *fp, unsigned reg)
{
        update_dest(ctx, reg);
        print_alu_reg(ctx, fp, reg, true);
}

/* For 16-bit+ masks, we read off from the 8-bit mask field. For 16-bit (vec8),
 * it's just one bit per channel, easy peasy. For 32-bit (vec4), it's one bit
 * per channel with one duplicate bit in the middle. For 64-bit (vec2), it's
 * one-bit per channel with _3_ duplicate bits in the middle. Basically, just
 * subdividing the 128-bit word in 16-bit increments. For 64-bit, we uppercase
 * the mask to make it obvious what happened */

static void
print_alu_mask(FILE *fp, uint8_t mask, unsigned bits, midgard_shrink_mode shrink_mode)
{
        /* Skip 'complete' masks */

        if (shrink_mode == midgard_shrink_mode_none && mask == 0xFF)
                return;

        fprintf(fp, ".");

        unsigned skip = MAX2(bits / 16, 1);
        bool uppercase = bits > 32;
        bool tripped = false;

        /* To apply an upper destination shrink_mode, we "shift" the alphabet.
         * E.g. with an upper shrink_mode on 32-bit, instead of xyzw, print efgh.
         * For upper 16-bit, instead of xyzwefgh, print ijklmnop */

        const char *alphabet = components;

        if (shrink_mode == midgard_shrink_mode_upper) {
                assert(bits != 8);
                alphabet += (128 / bits);
        }

        for (unsigned i = 0; i < 8; i += skip) {
                bool a = (mask & (1 << i)) != 0;

                for (unsigned j = 1; j < skip; ++j) {
                        bool dupe = (mask & (1 << (i + j))) != 0;
                        tripped |= (dupe != a);
                }

                if (a) {
                        /* TODO: handle shrinking from 16-bit */
                        unsigned comp_idx = bits == 8 ? i * 2 : i;
                        char c = alphabet[comp_idx / skip];

                        if (uppercase) {
                                c = toupper(c);
                                assert(c == 'X' || c == 'Y');
                        }

                        fprintf(fp, "%c", c);
                        if (bits == 8)
                                fprintf(fp, "%c", alphabet[comp_idx+1]);
                }
        }

        if (tripped)
                fprintf(fp, " /* %X */", mask);
}

/* TODO: 16-bit mode */
static void
print_ldst_mask(FILE *fp, unsigned mask, unsigned swizzle) {
        fprintf(fp, ".");

        for (unsigned i = 0; i < 4; ++i) {
                bool write = (mask & (1 << i)) != 0;
                unsigned c = (swizzle >> (i * 2)) & 3;
                /* We can't omit the swizzle here since many ldst ops have a
                 * combined swizzle/writemask, and it would be ambiguous to not
                 * print the masked-out components. */
                fprintf(fp, "%c", write ? components[c] : '~');
        }
}

static void
print_tex_mask(FILE *fp, unsigned mask, bool upper)
{
        if (mask == 0xF) {
                if (upper)
                        fprintf(fp, "'");

                return;
        }

        fprintf(fp, ".");

        for (unsigned i = 0; i < 4; ++i) {
                bool a = (mask & (1 << i)) != 0;
                if (a)
                        fprintf(fp, "%c", components[i + (upper ? 4 : 0)]);
        }
}

static void
print_vector_field(disassemble_context *ctx, FILE *fp, const char *name,
                   uint16_t *words, uint16_t reg_word,
                   const midgard_constants *consts, unsigned tabs, bool verbose)
{
        midgard_reg_info *reg_info = (midgard_reg_info *)&reg_word;
        midgard_vector_alu *alu_field = (midgard_vector_alu *) words;
        midgard_reg_mode mode = alu_field->reg_mode;
        midgard_alu_op op = alu_field->op;
        unsigned shrink_mode = alu_field->shrink_mode;
        bool is_int = midgard_is_integer_op(op);
        bool is_int_out = midgard_is_integer_out_op(op);

        if (verbose)
                fprintf(fp, "%s.", name);

        bool is_instruction_int = print_alu_opcode(fp, alu_field->op);

        /* Print lane width */
        fprintf(fp, ".%c%d", is_int_out ? 'i' : 'f', bits_for_mode(mode));

        fprintf(fp, " ");

        /* Mask denoting status of 8-lanes */
        uint8_t mask = alu_field->mask;

        /* First, print the destination */
        print_dest(ctx, fp, reg_info->out_reg);

        if (shrink_mode != midgard_shrink_mode_none) {
                bool shrinkable = (mode != midgard_reg_mode_8);
                bool known = shrink_mode != 0x3; /* Unused value */

                if (!(shrinkable && known))
                        fprintf(fp, "/* do%u */ ", shrink_mode);
        }

        /* Instructions like fdot4 do *not* replicate, ensure the
         * mask is of only a single component */

        unsigned rep = GET_CHANNEL_COUNT(alu_opcode_props[op].props);

        if (rep) {
                unsigned comp_mask = condense_writemask(mask, bits_for_mode(mode));
                unsigned num_comp = util_bitcount(comp_mask);
                if (num_comp != 1)
                        fprintf(fp, "/* err too many components */");
        }
        print_alu_mask(fp, mask, bits_for_mode(mode), shrink_mode);

        /* Print output modifiers */

        print_alu_outmod(fp, alu_field->outmod, is_int_out, shrink_mode != midgard_shrink_mode_none);

        /* Mask out unused components based on the writemask, but don't mask out
         * components that are used for interlane instructions like fdot3. */
        uint8_t src_mask =
                rep ? expand_writemask(mask_of(rep), log2(128 / bits_for_mode(mode))) : mask;

        fprintf(fp, ", ");

        if (reg_info->src1_reg == REGISTER_CONSTANT)
                print_vector_constants(fp, alu_field->src1, consts, alu_field);
        else {
                midgard_special_arg_mod argmod = midgard_alu_special_arg_mod(op, 1);
                print_vector_src(ctx, fp, alu_field->src1, mode, reg_info->src1_reg,
                                 shrink_mode, src_mask, is_int, argmod);
        }

        fprintf(fp, ", ");

        if (reg_info->src2_imm) {
                uint16_t imm = decode_vector_imm(reg_info->src2_reg, alu_field->src2 >> 2);
                print_immediate(fp, imm, is_instruction_int);
        } else if (reg_info->src2_reg == REGISTER_CONSTANT) {
                print_vector_constants(fp, alu_field->src2, consts, alu_field);
        } else {
                midgard_special_arg_mod argmod = midgard_alu_special_arg_mod(op, 2);
                print_vector_src(ctx, fp, alu_field->src2, mode, reg_info->src2_reg,
                                 shrink_mode, src_mask, is_int, argmod);
        }

        ctx->midg_stats.instruction_count++;
        fprintf(fp, "\n");
}

static void
print_scalar_src(disassemble_context *ctx, FILE *fp, bool is_int, unsigned src_binary, unsigned reg)
{
        midgard_scalar_alu_src *src = (midgard_scalar_alu_src *)&src_binary;

        print_alu_reg(ctx, fp, reg, false);

        unsigned c = src->component;

        if (src->full) {
                assert((c & 1) == 0);
                c >>= 1;
        }

        fprintf(fp, ".%c", components[c]);

        print_srcmod(fp, is_int, !src->full, src->mod, true);
}

static uint16_t
decode_scalar_imm(unsigned src2_reg, unsigned imm)
{
        uint16_t ret;
        ret = src2_reg << 11;
        ret |= (imm & 3) << 9;
        ret |= (imm & 4) << 6;
        ret |= (imm & 0x38) << 2;
        ret |= imm >> 6;
        return ret;
}

static void
print_scalar_field(disassemble_context *ctx, FILE *fp, const char *name,
                   uint16_t *words, uint16_t reg_word,
                   const midgard_constants *consts, unsigned tabs, bool verbose)
{
        midgard_reg_info *reg_info = (midgard_reg_info *)&reg_word;
        midgard_scalar_alu *alu_field = (midgard_scalar_alu *) words;
        bool is_int = midgard_is_integer_op(alu_field->op);
        bool is_int_out = midgard_is_integer_out_op(alu_field->op);
        bool full = alu_field->output_full;

        if (alu_field->unknown)
                fprintf(fp, "scalar ALU unknown bit set\n");

        if (verbose)
                fprintf(fp, "%s.", name);

        bool is_instruction_int = print_alu_opcode(fp, alu_field->op);

        /* Print lane width, in this case the lane width is always 32-bit, but
         * we print it anyway to make it consistent with the other instructions. */
        fprintf(fp, ".%c32", is_int_out ? 'i' : 'f');

        fprintf(fp, " ");

        print_dest(ctx, fp, reg_info->out_reg);
        unsigned c = alu_field->output_component;

        if (full) {
                assert((c & 1) == 0);
                c >>= 1;
        }

        fprintf(fp, ".%c", components[c]);

        print_alu_outmod(fp, alu_field->outmod, is_int_out, !full);

        fprintf(fp, ", ");

        if (reg_info->src1_reg == REGISTER_CONSTANT)
                print_scalar_constant(fp, alu_field->src1, consts, alu_field);
        else
                print_scalar_src(ctx, fp, is_int, alu_field->src1, reg_info->src1_reg);

        fprintf(fp, ", ");

        if (reg_info->src2_imm) {
                uint16_t imm = decode_scalar_imm(reg_info->src2_reg,
                                                 alu_field->src2);
                print_immediate(fp, imm, is_instruction_int);
	} else if (reg_info->src2_reg == REGISTER_CONSTANT) {
                print_scalar_constant(fp, alu_field->src2, consts, alu_field);
        } else
                print_scalar_src(ctx, fp, is_int, alu_field->src2, reg_info->src2_reg);

        ctx->midg_stats.instruction_count++;
        fprintf(fp, "\n");
}

static void
print_branch_op(FILE *fp, unsigned op)
{
        switch (op) {
        case midgard_jmp_writeout_op_branch_uncond:
                fprintf(fp, "uncond.");
                break;

        case midgard_jmp_writeout_op_branch_cond:
                fprintf(fp, "cond.");
                break;

        case midgard_jmp_writeout_op_writeout:
                fprintf(fp, "write.");
                break;

        case midgard_jmp_writeout_op_tilebuffer_pending:
                fprintf(fp, "tilebuffer.");
                break;

        case midgard_jmp_writeout_op_discard:
                fprintf(fp, "discard.");
                break;

        default:
                fprintf(fp, "unk%u.", op);
                break;
        }
}

static void
print_branch_cond(FILE *fp, int cond)
{
        switch (cond) {
        case midgard_condition_write0:
                fprintf(fp, "write0");
                break;

        case midgard_condition_false:
                fprintf(fp, "false");
                break;

        case midgard_condition_true:
                fprintf(fp, "true");
                break;

        case midgard_condition_always:
                fprintf(fp, "always");
                break;

        default:
                fprintf(fp, "unk%X", cond);
                break;
        }
}

static bool
print_compact_branch_writeout_field(disassemble_context *ctx, FILE *fp, uint16_t word)
{
        midgard_jmp_writeout_op op = word & 0x7;
        ctx->midg_stats.instruction_count++;

        switch (op) {
        case midgard_jmp_writeout_op_branch_uncond: {
                midgard_branch_uncond br_uncond;
                memcpy((char *) &br_uncond, (char *) &word, sizeof(br_uncond));
                fprintf(fp, "br.uncond ");

                if (br_uncond.unknown != 1)
                        fprintf(fp, "unknown:%u, ", br_uncond.unknown);

                if (br_uncond.offset >= 0)
                        fprintf(fp, "+");

                fprintf(fp, "%d -> %s", br_uncond.offset,
                                midgard_tag_props[br_uncond.dest_tag].name);
                fprintf(fp, "\n");

                return br_uncond.offset >= 0;
        }

        case midgard_jmp_writeout_op_branch_cond:
        case midgard_jmp_writeout_op_writeout:
        case midgard_jmp_writeout_op_discard:
        default: {
                midgard_branch_cond br_cond;
                memcpy((char *) &br_cond, (char *) &word, sizeof(br_cond));

                fprintf(fp, "br.");

                print_branch_op(fp, br_cond.op);
                print_branch_cond(fp, br_cond.cond);

                fprintf(fp, " ");

                if (br_cond.offset >= 0)
                        fprintf(fp, "+");

                fprintf(fp, "%d -> %s", br_cond.offset,
                                midgard_tag_props[br_cond.dest_tag].name);
                fprintf(fp, "\n");

                return br_cond.offset >= 0;
        }
        }

        return false;
}

static bool
print_extended_branch_writeout_field(disassemble_context *ctx, FILE *fp, uint8_t *words,
                                     unsigned next)
{
        midgard_branch_extended br;
        memcpy((char *) &br, (char *) words, sizeof(br));

        fprintf(fp, "brx.");

        print_branch_op(fp, br.op);

        /* Condition codes are a LUT in the general case, but simply repeated 8 times for single-channel conditions.. Check this. */

        bool single_channel = true;

        for (unsigned i = 0; i < 16; i += 2) {
                single_channel &= (((br.cond >> i) & 0x3) == (br.cond & 0x3));
        }

        if (single_channel)
                print_branch_cond(fp, br.cond & 0x3);
        else
                fprintf(fp, "lut%X", br.cond);

        if (br.unknown)
                fprintf(fp, ".unknown%u", br.unknown);

        fprintf(fp, " ");

        if (br.offset >= 0)
                fprintf(fp, "+");

        fprintf(fp, "%d -> %s\n", br.offset,
                        midgard_tag_props[br.dest_tag].name);

        unsigned I = next + br.offset * 4;

        if (ctx->midg_tags[I] && ctx->midg_tags[I] != br.dest_tag) {
                fprintf(fp, "\t/* XXX TAG ERROR: jumping to %s but tagged %s \n",
                        midgard_tag_props[br.dest_tag].name,
                        midgard_tag_props[ctx->midg_tags[I]].name);
        }

        ctx->midg_tags[I] = br.dest_tag;

        ctx->midg_stats.instruction_count++;
        return br.offset >= 0;
}

static unsigned
num_alu_fields_enabled(uint32_t control_word)
{
        unsigned ret = 0;

        if ((control_word >> 17) & 1)
                ret++;

        if ((control_word >> 19) & 1)
                ret++;

        if ((control_word >> 21) & 1)
                ret++;

        if ((control_word >> 23) & 1)
                ret++;

        if ((control_word >> 25) & 1)
                ret++;

        return ret;
}

static bool
print_alu_word(disassemble_context *ctx, FILE *fp, uint32_t *words,
               unsigned num_quad_words, unsigned tabs, unsigned next,
               bool verbose)
{
        uint32_t control_word = words[0];
        uint16_t *beginning_ptr = (uint16_t *)(words + 1);
        unsigned num_fields = num_alu_fields_enabled(control_word);
        uint16_t *word_ptr = beginning_ptr + num_fields;
        unsigned num_words = 2 + num_fields;
        const midgard_constants *consts = NULL;
        bool branch_forward = false;

        if ((control_word >> 17) & 1)
                num_words += 3;

        if ((control_word >> 19) & 1)
                num_words += 2;

        if ((control_word >> 21) & 1)
                num_words += 3;

        if ((control_word >> 23) & 1)
                num_words += 2;

        if ((control_word >> 25) & 1)
                num_words += 3;

        if ((control_word >> 26) & 1)
                num_words += 1;

        if ((control_word >> 27) & 1)
                num_words += 3;

        if (num_quad_words > (num_words + 7) / 8) {
                assert(num_quad_words == (num_words + 15) / 8);
                //Assume that the extra quadword is constants
                consts = (midgard_constants *)(words + (4 * num_quad_words - 4));
        }

        if ((control_word >> 16) & 1)
                fprintf(fp, "unknown bit 16 enabled\n");

        if ((control_word >> 17) & 1) {
                print_vector_field(ctx, fp, "vmul", word_ptr, *beginning_ptr, consts, tabs, verbose);
                beginning_ptr += 1;
                word_ptr += 3;
        }

        if ((control_word >> 18) & 1)
                fprintf(fp, "unknown bit 18 enabled\n");

        if ((control_word >> 19) & 1) {
                print_scalar_field(ctx, fp, "sadd", word_ptr, *beginning_ptr, consts, tabs, verbose);
                beginning_ptr += 1;
                word_ptr += 2;
        }

        if ((control_word >> 20) & 1)
                fprintf(fp, "unknown bit 20 enabled\n");

        if ((control_word >> 21) & 1) {
                print_vector_field(ctx, fp, "vadd", word_ptr, *beginning_ptr, consts, tabs, verbose);
                beginning_ptr += 1;
                word_ptr += 3;
        }

        if ((control_word >> 22) & 1)
                fprintf(fp, "unknown bit 22 enabled\n");

        if ((control_word >> 23) & 1) {
                print_scalar_field(ctx, fp, "smul", word_ptr, *beginning_ptr, consts, tabs, verbose);
                beginning_ptr += 1;
                word_ptr += 2;
        }

        if ((control_word >> 24) & 1)
                fprintf(fp, "unknown bit 24 enabled\n");

        if ((control_word >> 25) & 1) {
                print_vector_field(ctx, fp, "lut", word_ptr, *beginning_ptr, consts, tabs, verbose);
                word_ptr += 3;
        }

        if ((control_word >> 26) & 1) {
                branch_forward |= print_compact_branch_writeout_field(ctx, fp, *word_ptr);
                word_ptr += 1;
        }

        if ((control_word >> 27) & 1) {
                branch_forward |= print_extended_branch_writeout_field(ctx, fp, (uint8_t *) word_ptr, next);
                word_ptr += 3;
        }

        if (consts)
                fprintf(fp, "uconstants 0x%X, 0x%X, 0x%X, 0x%X\n",
                        consts->u32[0], consts->u32[1],
                        consts->u32[2], consts->u32[3]);

        return branch_forward;
}

/* TODO: how can we use this now that we know that these params can't be known
 * before run time in every single case? Maybe just use it in the cases we can? */
UNUSED static void
print_varying_parameters(FILE *fp, midgard_load_store_word *word)
{
        midgard_varying_params p = midgard_unpack_varying_params(*word);

        /* If a varying, there are qualifiers */
        if (p.flat_shading)
                fprintf(fp, ".flat");

        if (p.perspective_correction)
                fprintf(fp, ".correction");

        if (p.centroid_mapping)
                fprintf(fp, ".centroid");

        if (p.interpolate_sample)
                fprintf(fp, ".sample");

        switch (p.modifier) {
                case midgard_varying_mod_perspective_y:
                        fprintf(fp, ".perspectivey");
                        break;
                case midgard_varying_mod_perspective_z:
                        fprintf(fp, ".perspectivez");
                        break;
                case midgard_varying_mod_perspective_w:
                        fprintf(fp, ".perspectivew");
                        break;
                default:
                        unreachable("invalid varying modifier");
                        break;
        }
}

static bool
is_op_varying(unsigned op)
{
        switch (op) {
        case midgard_op_st_vary_16:
        case midgard_op_st_vary_32:
        case midgard_op_st_vary_32i:
        case midgard_op_st_vary_32u:
        case midgard_op_ld_vary_16:
        case midgard_op_ld_vary_32:
        case midgard_op_ld_vary_32i:
        case midgard_op_ld_vary_32u:
                return true;
        }

        return false;
}

static bool
is_op_attribute(unsigned op)
{
        switch (op) {
        case midgard_op_ld_attr_16:
        case midgard_op_ld_attr_32:
        case midgard_op_ld_attr_32i:
        case midgard_op_ld_attr_32u:
                return true;
        }

        return false;
}

/* Helper to print integer well-formatted, but only when non-zero. */
static void
midgard_print_sint(FILE *fp, int n)
{
        if (n > 0)
                fprintf(fp, " + 0x%X", n);
        else if (n < 0)
                fprintf(fp, " - 0x%X", -n);
}

static void
update_stats(signed *stat, unsigned address)
{
        if (*stat >= 0)
                *stat = MAX2(*stat, address + 1);
}

static void
print_load_store_instr(disassemble_context *ctx, FILE *fp, uint64_t data, bool verbose)
{
        midgard_load_store_word *word = (midgard_load_store_word *) &data;

        print_ld_st_opcode(fp, word->op);

        if (word->op == midgard_op_trap) {
                fprintf(fp, " 0x%X\n", word->signed_offset);
                return;
        }

        /* Print opcode modifiers */

        if (OP_USES_ATTRIB(word->op)) {
                /* Print non-default attribute tables */
                bool default_secondary =
                        (word->op == midgard_op_st_vary_32) ||
                        (word->op == midgard_op_st_vary_16) ||
                        (word->op == midgard_op_st_vary_32u) ||
                        (word->op == midgard_op_st_vary_32i) ||
                        (word->op == midgard_op_ld_vary_32) ||
                        (word->op == midgard_op_ld_vary_16) ||
                        (word->op == midgard_op_ld_vary_32u) ||
                        (word->op == midgard_op_ld_vary_32i);

                bool default_primary =
                        (word->op == midgard_op_ld_attr_32) ||
                        (word->op == midgard_op_ld_attr_16) ||
                        (word->op == midgard_op_ld_attr_32u) ||
                        (word->op == midgard_op_ld_attr_32i);

                bool has_default = (default_secondary || default_primary);
                bool is_secondary = (word->index_format >> 1);

                if (has_default && (is_secondary != default_secondary))
                        fprintf(fp, ".%s", is_secondary ? "secondary" : "primary");
        } else if (word->op == midgard_op_ld_cubemap_coords || OP_IS_PROJECTION(word->op))
                fprintf(fp, ".%s", word->bitsize_toggle ? "f32" : "f16");

        fprintf(fp, " ");

        /* src/dest register */

        if (!OP_IS_STORE(word->op)) {
                print_ldst_write_reg(fp, word->reg);

                /* Some opcodes don't have a swizzable src register, and
                 * instead the swizzle is applied before the result is written
                 * to the dest reg. For these ops, we combine the writemask
                 * with the swizzle to display them in the disasm compactly. */
                unsigned swizzle = word->swizzle;
                if ((OP_IS_REG2REG_LDST(word->op) &&
                        word->op != midgard_op_lea &&
                        word->op != midgard_op_lea_image) || OP_IS_ATOMIC(word->op))
                        swizzle = 0xE4;
                print_ldst_mask(fp, word->mask, swizzle);
        } else {
                print_ldst_read_reg(fp, word->reg);
                print_vec_swizzle(fp, word->swizzle, midgard_src_passthrough,
                                  midgard_reg_mode_32, 0xFF);
        }

        /* ld_ubo args */
        if (OP_IS_UBO_READ(word->op)) {
                if (word->signed_offset & 1) { /* buffer index imm */
                        unsigned imm = midgard_unpack_ubo_index_imm(*word);
                        fprintf(fp, ", %u", imm);
                } else { /* buffer index from reg */
                        fprintf(fp, ", ");
                        print_ldst_read_reg(fp, word->arg_reg);
                        fprintf(fp, ".%c", components[word->arg_comp]);
                }

                fprintf(fp, ", ");
                print_ldst_read_reg(fp, word->index_reg);
                fprintf(fp, ".%c", components[word->index_comp]);
                if (word->index_shift)
                        fprintf(fp, " lsl %u",  word->index_shift);
                midgard_print_sint(fp, UNPACK_LDST_UBO_OFS(word->signed_offset));
        }

        /* mem addr expression */
        if (OP_HAS_ADDRESS(word->op)) {
                fprintf(fp, ", ");
                bool first = true;

                /* Skip printing zero */
                if (word->arg_reg != 7 || verbose) {
                        print_ldst_read_reg(fp, word->arg_reg);
                        fprintf(fp, ".u%d.%c",
                                word->bitsize_toggle ? 64 : 32, components[word->arg_comp]);
                        first = false;
                }

                if ((word->op < midgard_op_atomic_cmpxchg ||
                     word->op > midgard_op_atomic_cmpxchg64_be) &&
                     word->index_reg != 0x7) {
                        if (!first)
                                fprintf(fp, " + ");

                        print_ldst_read_reg(fp, word->index_reg);
                        fprintf(fp, "%s.%c",
                                index_format_names[word->index_format],
                                components[word->index_comp]);
                        if (word->index_shift)
                                fprintf(fp, " lsl %u",  word->index_shift);
                }

                midgard_print_sint(fp, word->signed_offset);
        }

        /* src reg for reg2reg ldst opcodes */
        if (OP_IS_REG2REG_LDST(word->op)) {
                fprintf(fp, ", ");
                print_ldst_read_reg(fp, word->arg_reg);
                print_vec_swizzle(fp, word->swizzle, midgard_src_passthrough,
                                  midgard_reg_mode_32, 0xFF);
        }

        /* atomic ops encode the source arg where the ldst swizzle would be. */
        if (OP_IS_ATOMIC(word->op)) {
                unsigned src = (word->swizzle >> 2) & 0x7;
                unsigned src_comp = word->swizzle & 0x3;
                fprintf(fp, ", ");
                print_ldst_read_reg(fp, src);
                fprintf(fp, ".%c", components[src_comp]);
        }

        /* CMPXCHG encodes the extra comparison arg where the index reg would be. */
        if (word->op >= midgard_op_atomic_cmpxchg &&
            word->op <= midgard_op_atomic_cmpxchg64_be) {
                fprintf(fp, ", ");
                print_ldst_read_reg(fp, word->index_reg);
                fprintf(fp, ".%c", components[word->index_comp]);
        }

        /* index reg for attr/vary/images, selector for ld/st_special */
        if (OP_IS_SPECIAL(word->op) || OP_USES_ATTRIB(word->op)) {
                fprintf(fp, ", ");
                print_ldst_read_reg(fp, word->index_reg);
                fprintf(fp, ".%c", components[word->index_comp]);
                if (word->index_shift)
                        fprintf(fp, " lsl %u",  word->index_shift);
                midgard_print_sint(fp, UNPACK_LDST_ATTRIB_OFS(word->signed_offset));
        }

        /* vertex reg for attrib/varying ops, coord reg for image ops */
        if (OP_USES_ATTRIB(word->op)) {
                fprintf(fp, ", ");
                print_ldst_read_reg(fp, word->arg_reg);

                if (OP_IS_IMAGE(word->op))
                        fprintf(fp, ".u%d", word->bitsize_toggle ? 64 : 32);

                fprintf(fp, ".%c", components[word->arg_comp]);

                if (word->bitsize_toggle && !OP_IS_IMAGE(word->op))
                        midgard_print_sint(fp, UNPACK_LDST_VERTEX_OFS(word->signed_offset));
        }

        /* TODO: properly decode format specifier for PACK/UNPACK ops */
        if (OP_IS_PACK_COLOUR(word->op) || OP_IS_UNPACK_COLOUR(word->op)) {
                fprintf(fp, ", ");
                unsigned format_specifier = (word->signed_offset << 4) | word->index_shift;
                fprintf(fp, "0x%X", format_specifier);
        }

        fprintf(fp, "\n");

        /* Debugging stuff */

        if (is_op_varying(word->op)) {
                /* Do some analysis: check if direct access */

                if (word->index_reg == 0x7 && ctx->midg_stats.varying_count >= 0)
                        update_stats(&ctx->midg_stats.varying_count,
                                     UNPACK_LDST_ATTRIB_OFS(word->signed_offset));
                else
                        ctx->midg_stats.varying_count = -16;
        } else if (is_op_attribute(word->op)) {
                if (word->index_reg == 0x7 && ctx->midg_stats.attribute_count >= 0)
                        update_stats(&ctx->midg_stats.attribute_count,
                                     UNPACK_LDST_ATTRIB_OFS(word->signed_offset));
                else
                        ctx->midg_stats.attribute_count = -16;
        }

        if (!OP_IS_STORE(word->op))
                update_dest(ctx, word->reg);

        if (OP_IS_UBO_READ(word->op))
                update_stats(&ctx->midg_stats.uniform_buffer_count,
                             UNPACK_LDST_UBO_OFS(word->signed_offset));

        ctx->midg_stats.instruction_count++;
}

static void
print_load_store_word(disassemble_context *ctx, FILE *fp, uint32_t *word, bool verbose)
{
        midgard_load_store *load_store = (midgard_load_store *) word;

        if (load_store->word1 != 3) {
                print_load_store_instr(ctx, fp, load_store->word1, verbose);
        }

        if (load_store->word2 != 3) {
                print_load_store_instr(ctx, fp, load_store->word2, verbose);
        }
}

static void
print_texture_reg_select(FILE *fp, uint8_t u, unsigned base)
{
        midgard_tex_register_select sel;
        memcpy(&sel, &u, sizeof(u));

        print_tex_reg(fp, base + sel.select, false);

        unsigned component = sel.component;

        /* Use the upper half in half-reg mode */
        if (sel.upper) {
                assert(!sel.full);
                component += 4;
        }

        fprintf(fp, ".%c.%d", components[component], sel.full ? 32 : 16);

        assert(sel.zero == 0);
}

static void
print_texture_format(FILE *fp, int format)
{
        /* Act like a modifier */
        fprintf(fp, ".");

        switch (format) {
                DEFINE_CASE(1, "1d");
                DEFINE_CASE(2, "2d");
                DEFINE_CASE(3, "3d");
                DEFINE_CASE(0, "cube");

        default:
                unreachable("Bad format");
        }
}

static bool
midgard_op_has_helpers(unsigned op)
{
        switch (op) {
        case midgard_tex_op_normal:
        case midgard_tex_op_derivative:
                return true;
        default:
                return false;
        }
}

static void
print_texture_op(FILE *fp, unsigned op)
{
        if (tex_opcode_props[op].name)
                fprintf(fp, "%s", tex_opcode_props[op].name);
        else
                fprintf(fp, "tex_op_%02X", op);
}

static bool
texture_op_takes_bias(unsigned op)
{
        return op == midgard_tex_op_normal;
}

static char
sampler_type_name(enum mali_sampler_type t)
{
        switch (t) {
        case MALI_SAMPLER_FLOAT:
                return 'f';
        case MALI_SAMPLER_UNSIGNED:
                return 'u';
        case MALI_SAMPLER_SIGNED:
                return 'i';
        default:
                return '?';
        }

}

static void
print_texture_barrier(FILE *fp, uint32_t *word)
{
        midgard_texture_barrier_word *barrier = (midgard_texture_barrier_word *) word;

        if (barrier->type != TAG_TEXTURE_4_BARRIER)
                fprintf(fp, "/* barrier tag %X != tex/bar */ ", barrier->type);

        if (!barrier->cont)
                fprintf(fp, "/* cont missing? */");

        if (!barrier->last)
                fprintf(fp, "/* last missing? */");

        if (barrier->zero1)
                fprintf(fp, "/* zero1 = 0x%X */ ", barrier->zero1);

        if (barrier->zero2)
                fprintf(fp, "/* zero2 = 0x%X */ ", barrier->zero2);

        if (barrier->zero3)
                fprintf(fp, "/* zero3 = 0x%X */ ", barrier->zero3);

        if (barrier->zero4)
                fprintf(fp, "/* zero4 = 0x%X */ ", barrier->zero4);

        if (barrier->zero5)
                fprintf(fp, "/* zero4 = 0x%" PRIx64 " */ ", barrier->zero5);

        if (barrier->out_of_order)
                fprintf(fp, ".ooo%u", barrier->out_of_order);

        fprintf(fp, "\n");
}

#undef DEFINE_CASE

static const char *
texture_mode(enum mali_texture_mode mode)
{
        switch (mode) {
        case TEXTURE_NORMAL: return "";
        case TEXTURE_SHADOW: return ".shadow";
        case TEXTURE_GATHER_SHADOW: return ".gather.shadow";
        case TEXTURE_GATHER_X: return ".gatherX";
        case TEXTURE_GATHER_Y: return ".gatherY";
        case TEXTURE_GATHER_Z: return ".gatherZ";
        case TEXTURE_GATHER_W: return ".gatherW";
        default: return "unk";
        }
}

static const char *
derivative_mode(enum mali_derivative_mode mode)
{
        switch (mode) {
        case TEXTURE_DFDX: return ".x";
        case TEXTURE_DFDY: return ".y";
        default: return "unk";
        }
}

static void
print_texture_word(disassemble_context *ctx, FILE *fp, uint32_t *word,
                   unsigned tabs, unsigned in_reg_base, unsigned out_reg_base)
{
        midgard_texture_word *texture = (midgard_texture_word *) word;
        ctx->midg_stats.helper_invocations |= midgard_op_has_helpers(texture->op);
        validate_sampler_type(texture->op, texture->sampler_type);

        /* Broad category of texture operation in question */
        print_texture_op(fp, texture->op);

        /* Barriers use a dramatically different code path */
        if (texture->op == midgard_tex_op_barrier) {
                print_texture_barrier(fp, word);
                return;
        } else if (texture->type == TAG_TEXTURE_4_BARRIER)
                fprintf (fp, "/* nonbarrier had tex/bar tag */ ");
        else if (texture->type == TAG_TEXTURE_4_VTX)
                fprintf (fp, ".vtx");

        if (texture->op == midgard_tex_op_derivative)
                fprintf(fp, "%s", derivative_mode(texture->mode));
        else
                fprintf(fp, "%s", texture_mode(texture->mode));

        /* Specific format in question */
        print_texture_format(fp, texture->format);

        /* Instruction "modifiers" parallel the ALU instructions. */

        if (texture->cont)
                fprintf(fp, ".cont");

        if (texture->last)
                fprintf(fp, ".last");

        if (texture->out_of_order)
                fprintf(fp, ".ooo%u", texture->out_of_order);

        fprintf(fp, " ");
        print_tex_reg(fp, out_reg_base + texture->out_reg_select, true);
        print_tex_mask(fp, texture->mask, texture->out_upper);
        fprintf(fp, ".%c%d", texture->sampler_type == MALI_SAMPLER_FLOAT ? 'f' : 'i',
                             texture->out_full ? 32 : 16);
        assert(!(texture->out_full && texture->out_upper));

        /* Output modifiers are only valid for float texture operations */
        if (texture->sampler_type == MALI_SAMPLER_FLOAT)
                print_outmod(fp, texture->outmod, false);

        fprintf(fp, ", ");

        /* Depending on whether we read from textures directly or indirectly,
         * we may be able to update our analysis */

        if (texture->texture_register) {
                fprintf(fp, "texture[");
                print_texture_reg_select(fp, texture->texture_handle, in_reg_base);
                fprintf(fp, "], ");

                /* Indirect, tut tut */
                ctx->midg_stats.texture_count = -16;
        } else {
                fprintf(fp, "texture%u, ", texture->texture_handle);
                update_stats(&ctx->midg_stats.texture_count, texture->texture_handle);
        }

        /* Print the type, GL style */
        fprintf(fp, "%csampler", sampler_type_name(texture->sampler_type));

        if (texture->sampler_register) {
                fprintf(fp, "[");
                print_texture_reg_select(fp, texture->sampler_handle, in_reg_base);
                fprintf(fp, "]");

                ctx->midg_stats.sampler_count = -16;
        } else {
                fprintf(fp, "%u", texture->sampler_handle);
                update_stats(&ctx->midg_stats.sampler_count, texture->sampler_handle);
        }

        print_vec_swizzle(fp, texture->swizzle, midgard_src_passthrough, midgard_reg_mode_32, 0xFF);

        fprintf(fp, ", ");

        midgard_src_expand_mode exp =
                texture->in_reg_upper ? midgard_src_expand_high : midgard_src_passthrough;
        print_tex_reg(fp, in_reg_base + texture->in_reg_select, false);
        print_vec_swizzle(fp, texture->in_reg_swizzle, exp, midgard_reg_mode_32, 0xFF);
        fprintf(fp, ".%d", texture->in_reg_full ? 32 : 16);
        assert(!(texture->in_reg_full && texture->in_reg_upper));

        /* There is *always* an offset attached. Of
         * course, that offset is just immediate #0 for a
         * GLES call that doesn't take an offset. If there
         * is a non-negative non-zero offset, this is
         * specified in immediate offset mode, with the
         * values in the offset_* fields as immediates. If
         * this is a negative offset, we instead switch to
         * a register offset mode, where the offset_*
         * fields become register triplets */

        if (texture->offset_register) {
                fprintf(fp, " + ");

                bool full = texture->offset & 1;
                bool select = texture->offset & 2;
                bool upper = texture->offset & 4;
                unsigned swizzle = texture->offset >> 3;
                midgard_src_expand_mode exp =
                        upper ? midgard_src_expand_high : midgard_src_passthrough;

                print_tex_reg(fp, in_reg_base + select, false);
                print_vec_swizzle(fp, swizzle, exp, midgard_reg_mode_32, 0xFF);
                fprintf(fp, ".%d", full ? 32 : 16);
                assert(!(texture->out_full && texture->out_upper));

                fprintf(fp, ", ");
        } else if (texture->offset) {
                /* Only select ops allow negative immediate offsets, verify */

                signed offset_x = (texture->offset & 0xF);
                signed offset_y = ((texture->offset >> 4) & 0xF);
                signed offset_z = ((texture->offset >> 8) & 0xF);

                bool neg_x = offset_x < 0;
                bool neg_y = offset_y < 0;
                bool neg_z = offset_z < 0;
                bool any_neg = neg_x || neg_y || neg_z;

                if (any_neg && texture->op != midgard_tex_op_fetch)
                        fprintf(fp, "/* invalid negative */ ");

                /* Regardless, just print the immediate offset */

                fprintf(fp, " + <%d, %d, %d>, ", offset_x, offset_y, offset_z);
        } else {
                fprintf(fp, ", ");
        }

        char lod_operand = texture_op_takes_bias(texture->op) ? '+' : '=';

        if (texture->lod_register) {
                fprintf(fp, "lod %c ", lod_operand);
                print_texture_reg_select(fp, texture->bias, in_reg_base);
                fprintf(fp, ", ");

                if (texture->bias_int)
                        fprintf(fp, " /* bias_int = 0x%X */", texture->bias_int);
        } else if (texture->op == midgard_tex_op_fetch) {
                /* For texel fetch, the int LOD is in the fractional place and
                 * there is no fraction. We *always* have an explicit LOD, even
                 * if it's zero. */

                if (texture->bias_int)
                        fprintf(fp, " /* bias_int = 0x%X */ ", texture->bias_int);

                fprintf(fp, "lod = %u, ", texture->bias);
        } else if (texture->bias || texture->bias_int) {
                signed bias_int = texture->bias_int;
                float bias_frac = texture->bias / 256.0f;
                float bias = bias_int + bias_frac;

                bool is_bias = texture_op_takes_bias(texture->op);
                char sign = (bias >= 0.0) ? '+' : '-';
                char operand = is_bias ? sign : '=';

                fprintf(fp, "lod %c %f, ", operand, fabsf(bias));
        }

        fprintf(fp, "\n");

        /* While not zero in general, for these simple instructions the
         * following unknowns are zero, so we don't include them */

        if (texture->unknown4 ||
            texture->unknown8) {
                fprintf(fp, "// unknown4 = 0x%x\n", texture->unknown4);
                fprintf(fp, "// unknown8 = 0x%x\n", texture->unknown8);
        }

        ctx->midg_stats.instruction_count++;
}

struct midgard_disasm_stats
disassemble_midgard(FILE *fp, uint8_t *code, size_t size, unsigned gpu_id, bool verbose)
{
        uint32_t *words = (uint32_t *) code;
        unsigned num_words = size / 4;
        int tabs = 0;

        bool branch_forward = false;

        int last_next_tag = -1;

        unsigned i = 0;

        disassemble_context ctx = {
                .midg_tags = calloc(sizeof(ctx.midg_tags[0]), num_words),
                .midg_stats = {0},
                .midg_ever_written = 0,
        };

        while (i < num_words) {
                unsigned tag = words[i] & 0xF;
                unsigned next_tag = (words[i] >> 4) & 0xF;
                unsigned num_quad_words = midgard_tag_props[tag].size;

                if (ctx.midg_tags[i] && ctx.midg_tags[i] != tag) {
                        fprintf(fp, "\t/* XXX: TAG ERROR branch, got %s expected %s */\n",
                                        midgard_tag_props[tag].name,
                                        midgard_tag_props[ctx.midg_tags[i]].name);
                }

                ctx.midg_tags[i] = tag;

                /* Check the tag. The idea is to ensure that next_tag is
                 * *always* recoverable from the disassembly, such that we may
                 * safely omit printing next_tag. To show this, we first
                 * consider that next tags are semantically off-byone -- we end
                 * up parsing tag n during step n+1. So, we ensure after we're
                 * done disassembling the next tag of the final bundle is BREAK
                 * and warn otherwise. We also ensure that the next tag is
                 * never INVALID. Beyond that, since the last tag is checked
                 * outside the loop, we can check one tag prior. If equal to
                 * the current tag (which is unique), we're done. Otherwise, we
                 * print if that tag was > TAG_BREAK, which implies the tag was
                 * not TAG_BREAK or TAG_INVALID. But we already checked for
                 * TAG_INVALID, so it's just if the last tag was TAG_BREAK that
                 * we're silent. So we throw in a print for break-next on at
                 * the end of the bundle (if it's not the final bundle, which
                 * we already check for above), disambiguating this case as
                 * well.  Hence in all cases we are unambiguous, QED. */

                if (next_tag == TAG_INVALID)
                        fprintf(fp, "\t/* XXX: invalid next tag */\n");

                if (last_next_tag > TAG_BREAK && last_next_tag != tag) {
                        fprintf(fp, "\t/* XXX: TAG ERROR sequence, got %s expexted %s */\n",
                                        midgard_tag_props[tag].name,
                                        midgard_tag_props[last_next_tag].name);
                }

                last_next_tag = next_tag;

                /* Tags are unique in the following way:
                 *
                 * INVALID, BREAK, UNKNOWN_*: verbosely printed
                 * TEXTURE_4_BARRIER: verified by barrier/!barrier op
                 * TEXTURE_4_VTX: .vtx tag printed
                 * TEXTURE_4: tetxure lack of barriers or .vtx
                 * TAG_LOAD_STORE_4: only load/store
                 * TAG_ALU_4/8/12/16: by number of instructions/constants
                 * TAG_ALU_4_8/12/16_WRITEOUT: ^^ with .writeout tag
                 */

                switch (tag) {
                case TAG_TEXTURE_4_VTX ... TAG_TEXTURE_4_BARRIER: {
                        bool interpipe_aliasing =
                                midgard_get_quirks(gpu_id) & MIDGARD_INTERPIPE_REG_ALIASING;

                        print_texture_word(&ctx, fp, &words[i], tabs,
                                        interpipe_aliasing ? 0 : REG_TEX_BASE,
                                        interpipe_aliasing ? REGISTER_LDST_BASE : REG_TEX_BASE);
                        break;
                }

                case TAG_LOAD_STORE_4:
                        print_load_store_word(&ctx, fp, &words[i], verbose);
                        break;

                case TAG_ALU_4 ... TAG_ALU_16_WRITEOUT:
                        branch_forward = print_alu_word(&ctx, fp, &words[i], num_quad_words, tabs, i + 4*num_quad_words, verbose);

                        /* TODO: infer/verify me */
                        if (tag >= TAG_ALU_4_WRITEOUT)
                                fprintf(fp, "writeout\n");

                        break;

                default:
                        fprintf(fp, "Unknown word type %u:\n", words[i] & 0xF);
                        num_quad_words = 1;
                        print_quad_word(fp, &words[i], tabs);
                        fprintf(fp, "\n");
                        break;
                }

                /* We are parsing per bundle anyway. Add before we start
                 * breaking out so we don't miss the final bundle. */

                ctx.midg_stats.bundle_count++;
                ctx.midg_stats.quadword_count += num_quad_words;

                /* Include a synthetic "break" instruction at the end of the
                 * bundle to signify that if, absent a branch, the shader
                 * execution will stop here. Stop disassembly at such a break
                 * based on a heuristic */

                if (next_tag == TAG_BREAK) {
                        if (branch_forward) {
                                fprintf(fp, "break\n");
                        } else {
                                fprintf(fp, "\n");
                                break;
                        }
                }

                fprintf(fp, "\n");

                i += 4 * num_quad_words;
        }

        if (last_next_tag != TAG_BREAK) {
                fprintf(fp, "/* XXX: shader ended with tag %s */\n",
                                midgard_tag_props[last_next_tag].name);
        }

        free(ctx.midg_tags);

        /* We computed work_count as max_work_registers, so add one to get the
         * count. If no work registers are written, you still have one work
         * reported, which is exactly what the hardware expects */

        ctx.midg_stats.work_count++;

        return ctx.midg_stats;
}