blob: 1bc98e4059689c82f7093d1aacf730aa48bf1f58 [file] [log] [blame]
/*
* Copyright (C) 2019 Connor Abbott <cwabbott0@gmail.com>
* Copyright (C) 2019 Lyude Paul <thatslyude@gmail.com>
* Copyright (C) 2019 Ryan Houdek <Sonicadvance1@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <stdbool.h>
#include <stdio.h>
#include <stdint.h>
#include <assert.h>
#include <inttypes.h>
#include <string.h>
#include "bifrost.h"
#include "disassemble.h"
#include "bi_print_common.h"
#include "util/compiler.h"
#include "util/macros.h"
// return bits (high, lo]
static uint64_t bits(uint32_t word, unsigned lo, unsigned high)
{
if (high == 32)
return word >> lo;
return (word & ((1 << high) - 1)) >> lo;
}
// each of these structs represents an instruction that's dispatched in one
// cycle. Note that these instructions are packed in funny ways within the
// clause, hence the need for a separate struct.
struct bifrost_alu_inst {
uint32_t fma_bits;
uint32_t add_bits;
uint64_t reg_bits;
};
static unsigned get_reg0(struct bifrost_regs regs)
{
if (regs.ctrl == 0)
return regs.reg0 | ((regs.reg1 & 0x1) << 5);
return regs.reg0 <= regs.reg1 ? regs.reg0 : 63 - regs.reg0;
}
static unsigned get_reg1(struct bifrost_regs regs)
{
return regs.reg0 <= regs.reg1 ? regs.reg1 : 63 - regs.reg1;
}
// this represents the decoded version of the ctrl register field.
struct bifrost_reg_ctrl {
bool read_reg0;
bool read_reg1;
struct bifrost_reg_ctrl_23 slot23;
};
static void dump_header(FILE *fp, struct bifrost_header header, bool verbose)
{
fprintf(fp, "ds(%u) ", header.dependency_slot);
if (header.staging_barrier)
fprintf(fp, "osrb ");
fprintf(fp, "%s ", bi_flow_control_name(header.flow_control));
if (header.suppress_inf)
fprintf(fp, "inf_suppress ");
if (header.suppress_nan)
fprintf(fp, "nan_suppress ");
if (header.flush_to_zero == BIFROST_FTZ_DX11)
fprintf(fp, "ftz_dx11 ");
else if (header.flush_to_zero == BIFROST_FTZ_ALWAYS)
fprintf(fp, "ftz_hsa ");
if (header.flush_to_zero == BIFROST_FTZ_ABRUPT)
fprintf(fp, "ftz_au ");
assert(!header.zero1);
assert(!header.zero2);
if (header.float_exceptions == BIFROST_EXCEPTIONS_DISABLED)
fprintf(fp, "fpe_ts ");
else if (header.float_exceptions == BIFROST_EXCEPTIONS_PRECISE_DIVISION)
fprintf(fp, "fpe_pd ");
else if (header.float_exceptions == BIFROST_EXCEPTIONS_PRECISE_SQRT)
fprintf(fp, "fpe_psqr ");
if (header.message_type)
fprintf(fp, "%s ", bi_message_type_name(header.message_type));
if (header.terminate_discarded_threads)
fprintf(fp, "td ");
if (header.next_clause_prefetch)
fprintf(fp, "ncph ");
if (header.next_message_type)
fprintf(fp, "next_%s ", bi_message_type_name(header.next_message_type));
if (header.dependency_wait != 0) {
fprintf(fp, "dwb(");
bool first = true;
for (unsigned i = 0; i < 8; i++) {
if (header.dependency_wait & (1 << i)) {
if (!first) {
fprintf(fp, ", ");
}
fprintf(fp, "%u", i);
first = false;
}
}
fprintf(fp, ") ");
}
fprintf(fp, "\n");
}
static struct bifrost_reg_ctrl DecodeRegCtrl(FILE *fp, struct bifrost_regs regs, bool first)
{
struct bifrost_reg_ctrl decoded = {};
unsigned ctrl;
if (regs.ctrl == 0) {
ctrl = regs.reg1 >> 2;
decoded.read_reg0 = !(regs.reg1 & 0x2);
decoded.read_reg1 = false;
} else {
ctrl = regs.ctrl;
decoded.read_reg0 = decoded.read_reg1 = true;
}
/* Modify control based on state */
if (first)
ctrl = (ctrl & 0x7) | ((ctrl & 0x8) << 1);
else if (regs.reg2 == regs.reg3)
ctrl += 16;
decoded.slot23 = bifrost_reg_ctrl_lut[ctrl];
ASSERTED struct bifrost_reg_ctrl_23 reserved = { 0 };
assert(memcmp(&decoded.slot23, &reserved, sizeof(reserved)));
return decoded;
}
static void dump_regs(FILE *fp, struct bifrost_regs srcs, bool first)
{
struct bifrost_reg_ctrl ctrl = DecodeRegCtrl(fp, srcs, first);
fprintf(fp, " # ");
if (ctrl.read_reg0)
fprintf(fp, "slot 0: r%u ", get_reg0(srcs));
if (ctrl.read_reg1)
fprintf(fp, "slot 1: r%u ", get_reg1(srcs));
const char *slot3_fma = ctrl.slot23.slot3_fma ? "FMA" : "ADD";
if (ctrl.slot23.slot2 == BIFROST_OP_WRITE)
fprintf(fp, "slot 2: r%u (write FMA) ", srcs.reg2);
else if (ctrl.slot23.slot2 == BIFROST_OP_WRITE_LO)
fprintf(fp, "slot 2: r%u (write lo FMA) ", srcs.reg2);
else if (ctrl.slot23.slot2 == BIFROST_OP_WRITE_HI)
fprintf(fp, "slot 2: r%u (write hi FMA) ", srcs.reg2);
else if (ctrl.slot23.slot2 == BIFROST_OP_READ)
fprintf(fp, "slot 2: r%u (read) ", srcs.reg2);
if (ctrl.slot23.slot3 == BIFROST_OP_WRITE)
fprintf(fp, "slot 3: r%u (write %s) ", srcs.reg3, slot3_fma);
else if (ctrl.slot23.slot3 == BIFROST_OP_WRITE_LO)
fprintf(fp, "slot 3: r%u (write lo %s) ", srcs.reg3, slot3_fma);
else if (ctrl.slot23.slot3 == BIFROST_OP_WRITE_HI)
fprintf(fp, "slot 3: r%u (write hi %s) ", srcs.reg3, slot3_fma);
if (srcs.fau_idx)
fprintf(fp, "fau %X ", srcs.fau_idx);
fprintf(fp, "\n");
}
static void
bi_disasm_dest_mask(FILE *fp, enum bifrost_reg_op op)
{
if (op == BIFROST_OP_WRITE_LO)
fprintf(fp, ".h0");
else if (op == BIFROST_OP_WRITE_HI)
fprintf(fp, ".h1");
}
void
bi_disasm_dest_fma(FILE *fp, struct bifrost_regs *next_regs, bool last)
{
/* If this is the last instruction, next_regs points to the first reg entry. */
struct bifrost_reg_ctrl ctrl = DecodeRegCtrl(fp, *next_regs, last);
if (ctrl.slot23.slot2 >= BIFROST_OP_WRITE) {
fprintf(fp, "r%u:t0", next_regs->reg2);
bi_disasm_dest_mask(fp, ctrl.slot23.slot2);
} else if (ctrl.slot23.slot3 >= BIFROST_OP_WRITE && ctrl.slot23.slot3_fma) {
fprintf(fp, "r%u:t0", next_regs->reg3);
bi_disasm_dest_mask(fp, ctrl.slot23.slot3);
} else
fprintf(fp, "t0");
}
void
bi_disasm_dest_add(FILE *fp, struct bifrost_regs *next_regs, bool last)
{
/* If this is the last instruction, next_regs points to the first reg entry. */
struct bifrost_reg_ctrl ctrl = DecodeRegCtrl(fp, *next_regs, last);
if (ctrl.slot23.slot3 >= BIFROST_OP_WRITE && !ctrl.slot23.slot3_fma) {
fprintf(fp, "r%u:t1", next_regs->reg3);
bi_disasm_dest_mask(fp, ctrl.slot23.slot3);
} else
fprintf(fp, "t1");
}
static void dump_const_imm(FILE *fp, uint32_t imm)
{
union {
float f;
uint32_t i;
} fi;
fi.i = imm;
fprintf(fp, "0x%08x /* %f */", imm, fi.f);
}
static void
dump_pc_imm(FILE *fp, uint64_t imm, unsigned branch_offset, enum bi_constmod mod, bool high32)
{
if (mod == BI_CONSTMOD_PC_HI && !high32) {
dump_const_imm(fp, imm);
return;
}
/* 60-bit sign-extend */
uint64_t zx64 = (imm << 4);
int64_t sx64 = zx64;
sx64 >>= 4;
/* 28-bit sign extend x 2 */
uint32_t imm32[2] = { (uint32_t) imm, (uint32_t) (imm >> 32) };
uint32_t zx32[2] = { imm32[0] << 4, imm32[1] << 4 };
int32_t sx32[2] = { zx32[0], zx32[1] };
sx32[0] >>= 4;
sx32[1] >>= 4;
int64_t offs = 0;
switch (mod) {
case BI_CONSTMOD_PC_LO:
offs = sx64;
break;
case BI_CONSTMOD_PC_HI:
offs = sx32[1];
break;
case BI_CONSTMOD_PC_LO_HI:
offs = sx32[high32];
break;
default:
unreachable("Invalid PC modifier");
}
assert((offs & 15) == 0);
fprintf(fp, "clause_%" PRId64, branch_offset + (offs / 16));
if (mod == BI_CONSTMOD_PC_LO && high32)
fprintf(fp, " >> 32");
/* While technically in spec, referencing the current clause as (pc +
* 0) likely indicates an unintended infinite loop */
if (offs == 0)
fprintf(fp, " /* XXX: likely an infinite loop */");
}
/* Convert an index to an embedded constant in FAU-RAM to the index of the
* embedded constant. No, it's not in order. Yes, really. */
static unsigned
const_fau_to_idx(unsigned fau_value)
{
unsigned map[8] = {
~0, ~0, 4, 5, 0, 1, 2, 3
};
assert(map[fau_value] < 6);
return map[fau_value];
}
static void dump_fau_src(FILE *fp, struct bifrost_regs srcs, unsigned branch_offset, struct bi_constants *consts, bool high32)
{
if (srcs.fau_idx & 0x80) {
unsigned uniform = (srcs.fau_idx & 0x7f);
fprintf(fp, "u%u.w%u", uniform, high32);
} else if (srcs.fau_idx >= 0x20) {
unsigned idx = const_fau_to_idx(srcs.fau_idx >> 4);
uint64_t imm = consts->raw[idx];
imm |= (srcs.fau_idx & 0xf);
if (consts->mods[idx] != BI_CONSTMOD_NONE)
dump_pc_imm(fp, imm, branch_offset, consts->mods[idx], high32);
else if (high32)
dump_const_imm(fp, imm >> 32);
else
dump_const_imm(fp, imm);
} else {
switch (srcs.fau_idx) {
case 0:
fprintf(fp, "#0");
break;
case 1:
fprintf(fp, "lane_id");
break;
case 2:
fprintf(fp, "warp_id");
break;
case 3:
fprintf(fp, "core_id");
break;
case 4:
fprintf(fp, "framebuffer_size");
break;
case 5:
fprintf(fp, "atest_datum");
break;
case 6:
fprintf(fp, "sample");
break;
case 8:
case 9:
case 10:
case 11:
case 12:
case 13:
case 14:
case 15:
fprintf(fp, "blend_descriptor_%u", (unsigned) srcs.fau_idx - 8);
break;
default:
fprintf(fp, "XXX - reserved%u", (unsigned) srcs.fau_idx);
break;
}
if (high32)
fprintf(fp, ".y");
else
fprintf(fp, ".x");
}
}
void
dump_src(FILE *fp, unsigned src, struct bifrost_regs srcs, unsigned branch_offset, struct bi_constants *consts, bool isFMA)
{
switch (src) {
case 0:
fprintf(fp, "r%u", get_reg0(srcs));
break;
case 1:
fprintf(fp, "r%u", get_reg1(srcs));
break;
case 2:
fprintf(fp, "r%u", srcs.reg2);
break;
case 3:
if (isFMA)
fprintf(fp, "#0");
else
fprintf(fp, "t"); // i.e. the output of FMA this cycle
break;
case 4:
dump_fau_src(fp, srcs, branch_offset, consts, false);
break;
case 5:
dump_fau_src(fp, srcs, branch_offset, consts, true);
break;
case 6:
fprintf(fp, "t0");
break;
case 7:
fprintf(fp, "t1");
break;
}
}
/* Tables for decoding M0, or if M0 == 7, M1 respectively.
*
* XXX: It's not clear if the third entry of M1_table corresponding to (7, 2)
* should have PC_LO_HI in the EC1 slot, or it's a weird hybrid mode? I would
* say this needs testing but no code should ever actually use this mode.
*/
static const enum bi_constmod M1_table[7][2] = {
{ BI_CONSTMOD_NONE, BI_CONSTMOD_NONE },
{ BI_CONSTMOD_PC_LO, BI_CONSTMOD_NONE },
{ BI_CONSTMOD_PC_LO, BI_CONSTMOD_PC_LO },
{ ~0, ~0 },
{ BI_CONSTMOD_PC_HI, BI_CONSTMOD_NONE },
{ BI_CONSTMOD_PC_HI, BI_CONSTMOD_PC_HI },
{ BI_CONSTMOD_PC_LO, BI_CONSTMOD_NONE },
};
static const enum bi_constmod M2_table[4][2] = {
{ BI_CONSTMOD_PC_LO_HI, BI_CONSTMOD_NONE },
{ BI_CONSTMOD_PC_LO_HI, BI_CONSTMOD_PC_HI },
{ BI_CONSTMOD_PC_LO_HI, BI_CONSTMOD_PC_LO_HI },
{ BI_CONSTMOD_PC_LO_HI, BI_CONSTMOD_PC_HI },
};
static void
decode_M(enum bi_constmod *mod, unsigned M1, unsigned M2, bool single)
{
if (M1 >= 8) {
mod[0] = BI_CONSTMOD_NONE;
if (!single)
mod[1] = BI_CONSTMOD_NONE;
return;
} else if (M1 == 7) {
assert(M2 < 4);
memcpy(mod, M2_table[M2], sizeof(*mod) * (single ? 1 : 2));
} else {
assert(M1 != 3);
memcpy(mod, M1_table[M1], sizeof(*mod) * (single ? 1 : 2));
}
}
static void dump_clause(FILE *fp, uint32_t *words, unsigned *size, unsigned offset, bool verbose)
{
// State for a decoded clause
struct bifrost_alu_inst instrs[8] = {};
struct bi_constants consts = {};
unsigned num_instrs = 0;
unsigned num_consts = 0;
uint64_t header_bits = 0;
unsigned i;
for (i = 0; ; i++, words += 4) {
if (verbose) {
fprintf(fp, "# ");
for (int j = 0; j < 4; j++)
fprintf(fp, "%08x ", words[3 - j]); // low bit on the right
fprintf(fp, "\n");
}
unsigned tag = bits(words[0], 0, 8);
// speculatively decode some things that are common between many formats, so we can share some code
struct bifrost_alu_inst main_instr = {};
// 20 bits
main_instr.add_bits = bits(words[2], 2, 32 - 13);
// 23 bits
main_instr.fma_bits = bits(words[1], 11, 32) | bits(words[2], 0, 2) << (32 - 11);
// 35 bits
main_instr.reg_bits = ((uint64_t) bits(words[1], 0, 11)) << 24 | (uint64_t) bits(words[0], 8, 32);
uint64_t const0 = bits(words[0], 8, 32) << 4 | (uint64_t) words[1] << 28 | bits(words[2], 0, 4) << 60;
uint64_t const1 = bits(words[2], 4, 32) << 4 | (uint64_t) words[3] << 32;
/* Z-bit */
bool stop = tag & 0x40;
if (verbose) {
fprintf(fp, "# tag: 0x%02x\n", tag);
}
if (tag & 0x80) {
/* Format 5 or 10 */
unsigned idx = stop ? 5 : 2;
main_instr.add_bits |= ((tag >> 3) & 0x7) << 17;
instrs[idx + 1] = main_instr;
instrs[idx].add_bits = bits(words[3], 0, 17) | ((tag & 0x7) << 17);
instrs[idx].fma_bits |= bits(words[2], 19, 32) << 10;
consts.raw[0] = bits(words[3], 17, 32) << 4;
} else {
bool done = false;
switch ((tag >> 3) & 0x7) {
case 0x0:
switch (tag & 0x7) {
case 0x3:
/* Format 1 */
main_instr.add_bits |= bits(words[3], 29, 32) << 17;
instrs[1] = main_instr;
num_instrs = 2;
done = stop;
break;
case 0x4:
/* Format 3 */
instrs[2].add_bits = bits(words[3], 0, 17) | bits(words[3], 29, 32) << 17;
instrs[2].fma_bits |= bits(words[2], 19, 32) << 10;
consts.raw[0] = const0;
decode_M(&consts.mods[0], bits(words[2], 4, 8), bits(words[2], 8, 12), true);
num_instrs = 3;
num_consts = 1;
done = stop;
break;
case 0x1:
case 0x5:
/* Format 4 */
instrs[2].add_bits = bits(words[3], 0, 17) | bits(words[3], 29, 32) << 17;
instrs[2].fma_bits |= bits(words[2], 19, 32) << 10;
main_instr.add_bits |= bits(words[3], 26, 29) << 17;
instrs[3] = main_instr;
if ((tag & 0x7) == 0x5) {
num_instrs = 4;
done = stop;
}
break;
case 0x6:
/* Format 8 */
instrs[5].add_bits = bits(words[3], 0, 17) | bits(words[3], 29, 32) << 17;
instrs[5].fma_bits |= bits(words[2], 19, 32) << 10;
consts.raw[0] = const0;
decode_M(&consts.mods[0], bits(words[2], 4, 8), bits(words[2], 8, 12), true);
num_instrs = 6;
num_consts = 1;
done = stop;
break;
case 0x7:
/* Format 9 */
instrs[5].add_bits = bits(words[3], 0, 17) | bits(words[3], 29, 32) << 17;
instrs[5].fma_bits |= bits(words[2], 19, 32) << 10;
main_instr.add_bits |= bits(words[3], 26, 29) << 17;
instrs[6] = main_instr;
num_instrs = 7;
done = stop;
break;
default:
unreachable("[INSTR_INVALID_ENC] Invalid tag bits");
}
break;
case 0x2:
case 0x3: {
/* Format 6 or 11 */
unsigned idx = ((tag >> 3) & 0x7) == 2 ? 4 : 7;
main_instr.add_bits |= (tag & 0x7) << 17;
instrs[idx] = main_instr;
consts.raw[0] |= (bits(words[2], 19, 32) | ((uint64_t) words[3] << 13)) << 19;
num_consts = 1;
num_instrs = idx + 1;
done = stop;
break;
}
case 0x4: {
/* Format 2 */
unsigned idx = stop ? 4 : 1;
main_instr.add_bits |= (tag & 0x7) << 17;
instrs[idx] = main_instr;
instrs[idx + 1].fma_bits |= bits(words[3], 22, 32);
instrs[idx + 1].reg_bits = bits(words[2], 19, 32) | (bits(words[3], 0, 22) << (32 - 19));
break;
}
case 0x1:
/* Format 0 - followed by constants */
num_instrs = 1;
done = stop;
FALLTHROUGH;
case 0x5:
/* Format 0 - followed by instructions */
header_bits = bits(words[2], 19, 32) | ((uint64_t) words[3] << (32 - 19));
main_instr.add_bits |= (tag & 0x7) << 17;
instrs[0] = main_instr;
break;
case 0x6:
case 0x7: {
/* Format 12 */
unsigned pos = tag & 0xf;
struct {
unsigned const_idx;
unsigned nr_tuples;
} pos_table[0x10] = {
{ 0, 1 },
{ 0, 2 },
{ 0, 4 },
{ 1, 3 },
{ 1, 5 },
{ 2, 4 },
{ 0, 7 },
{ 1, 6 },
{ 3, 5 },
{ 1, 8 },
{ 2, 7 },
{ 3, 6 },
{ 3, 8 },
{ 4, 7 },
{ 5, 6 },
{ ~0, ~0 }
};
ASSERTED bool valid_count = pos_table[pos].nr_tuples == num_instrs;
assert(valid_count && "INSTR_INVALID_ENC");
unsigned const_idx = pos_table[pos].const_idx;
if (num_consts < const_idx + 2)
num_consts = const_idx + 2;
consts.raw[const_idx] = const0;
consts.raw[const_idx + 1] = const1;
/* Calculate M values from A, B and 4-bit
* unsigned arithmetic. Mathematically it
* should be (A - B) % 16 but we use this
* alternate form to avoid sign issues */
unsigned A1 = bits(words[2], 0, 4);
unsigned B1 = bits(words[3], 28, 32);
unsigned A2 = bits(words[1], 0, 4);
unsigned B2 = bits(words[2], 28, 32);
unsigned M1 = (16 + A1 - B1) & 0xF;
unsigned M2 = (16 + A2 - B2) & 0xF;
decode_M(&consts.mods[const_idx], M1, M2, false);
done = stop;
break;
}
default:
break;
}
if (done)
break;
}
}
*size = i + 1;
if (verbose) {
fprintf(fp, "# header: %012" PRIx64 "\n", header_bits);
}
struct bifrost_header header;
memcpy((char *) &header, (char *) &header_bits, sizeof(struct bifrost_header));
dump_header(fp, header, verbose);
fprintf(fp, "{\n");
for (i = 0; i < num_instrs; i++) {
struct bifrost_regs regs, next_regs;
if (i + 1 == num_instrs) {
memcpy((char *) &next_regs, (char *) &instrs[0].reg_bits,
sizeof(next_regs));
} else {
memcpy((char *) &next_regs, (char *) &instrs[i + 1].reg_bits,
sizeof(next_regs));
}
memcpy((char *) &regs, (char *) &instrs[i].reg_bits, sizeof(regs));
if (verbose) {
fprintf(fp, " # regs: %016" PRIx64 "\n", instrs[i].reg_bits);
dump_regs(fp, regs, i == 0);
}
bi_disasm_fma(fp, instrs[i].fma_bits, &regs, &next_regs,
header.staging_register, offset, &consts,
i + 1 == num_instrs);
bi_disasm_add(fp, instrs[i].add_bits, &regs, &next_regs,
header.staging_register, offset, &consts,
i + 1 == num_instrs);
}
fprintf(fp, "}\n");
if (verbose) {
for (unsigned i = 0; i < num_consts; i++) {
fprintf(fp, "# const%d: %08" PRIx64 "\n", 2 * i, consts.raw[i] & 0xffffffff);
fprintf(fp, "# const%d: %08" PRIx64 "\n", 2 * i + 1, consts.raw[i] >> 32);
}
}
fprintf(fp, "\n");
return;
}
void disassemble_bifrost(FILE *fp, uint8_t *code, size_t size, bool verbose)
{
uint32_t *words = (uint32_t *) code;
uint32_t *words_end = words + (size / 4);
// used for displaying branch targets
unsigned offset = 0;
while (words != words_end) {
/* Shaders have zero bytes at the end for padding; stop
* disassembling when we hit them. */
if (*words == 0)
break;
fprintf(fp, "clause_%u:\n", offset);
unsigned size;
dump_clause(fp, words, &size, offset, verbose);
words += size * 4;
offset += size;
}
}