/*
* Copyright © 2012 Intel Corporation
*
* 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.
*/
/** @file brw_eu_compact.c
*
* Instruction compaction is a feature of gm45 and newer hardware that allows
* for a smaller instruction encoding.
*
* The instruction cache is on the order of 32KB, and many programs generate
* far more instructions than that. The instruction cache is built to barely
* keep up with instruction dispatch abaility in cache hit cases -- L1
* instruction cache misses that still hit in the next level could limit
* throughput by around 50%.
*
* The idea of instruction compaction is that most instructions use a tiny
* subset of the GPU functionality, so we can encode what would be a 16 byte
* instruction in 8 bytes using some lookup tables for various fields.
*/
#include <string.h>
#include "brw_compat.h"
#include "brw_context.h"
#include "brw_eu.h"
static const uint32_t gen6_control_index_table[32] = {
0b00000000000000000,
0b01000000000000000,
0b00110000000000000,
0b00000000100000000,
0b00010000000000000,
0b00001000100000000,
0b00000000100000010,
0b00000000000000010,
0b01000000100000000,
0b01010000000000000,
0b10110000000000000,
0b00100000000000000,
0b11010000000000000,
0b11000000000000000,
0b01001000100000000,
0b01000000000001000,
0b01000000000000100,
0b00000000000001000,
0b00000000000000100,
0b00111000100000000,
0b00001000100000010,
0b00110000100000000,
0b00110000000000001,
0b00100000000000001,
0b00110000000000010,
0b00110000000000101,
0b00110000000001001,
0b00110000000010000,
0b00110000000000011,
0b00110000000000100,
0b00110000100001000,
0b00100000000001001
};
static const uint32_t gen6_datatype_table[32] = {
0b001001110000000000,
0b001000110000100000,
0b001001110000000001,
0b001000000001100000,
0b001010110100101001,
0b001000000110101101,
0b001100011000101100,
0b001011110110101101,
0b001000000111101100,
0b001000000001100001,
0b001000110010100101,
0b001000000001000001,
0b001000001000110001,
0b001000001000101001,
0b001000000000100000,
0b001000001000110010,
0b001010010100101001,
0b001011010010100101,
0b001000000110100101,
0b001100011000101001,
0b001011011000101100,
0b001011010110100101,
0b001011110110100101,
0b001111011110111101,
0b001111011110111100,
0b001111011110111101,
0b001111011110011101,
0b001111011110111110,
0b001000000000100001,
0b001000000000100010,
0b001001111111011101,
0b001000001110111110,
};
static const uint32_t gen6_subreg_table[32] = {
0b000000000000000,
0b000000000000100,
0b000000110000000,
0b111000000000000,
0b011110000001000,
0b000010000000000,
0b000000000010000,
0b000110000001100,
0b001000000000000,
0b000001000000000,
0b000001010010100,
0b000000001010110,
0b010000000000000,
0b110000000000000,
0b000100000000000,
0b000000010000000,
0b000000000001000,
0b100000000000000,
0b000001010000000,
0b001010000000000,
0b001100000000000,
0b000000001010100,
0b101101010010100,
0b010100000000000,
0b000000010001111,
0b011000000000000,
0b111110000000000,
0b101000000000000,
0b000000000001111,
0b000100010001111,
0b001000010001111,
0b000110000000000,
};
static const uint32_t gen6_src_index_table[32] = {
0b000000000000,
0b010110001000,
0b010001101000,
0b001000101000,
0b011010010000,
0b000100100000,
0b010001101100,
0b010101110000,
0b011001111000,
0b001100101000,
0b010110001100,
0b001000100000,
0b010110001010,
0b000000000010,
0b010101010000,
0b010101101000,
0b111101001100,
0b111100101100,
0b011001110000,
0b010110001001,
0b010101011000,
0b001101001000,
0b010000101100,
0b010000000000,
0b001101110000,
0b001100010000,
0b001100000000,
0b010001101010,
0b001101111000,
0b000001110000,
0b001100100000,
0b001101010000,
};
static const uint32_t gen7_control_index_table[32] = {
0b0000000000000000010,
0b0000100000000000000,
0b0000100000000000001,
0b0000100000000000010,
0b0000100000000000011,
0b0000100000000000100,
0b0000100000000000101,
0b0000100000000000111,
0b0000100000000001000,
0b0000100000000001001,
0b0000100000000001101,
0b0000110000000000000,
0b0000110000000000001,
0b0000110000000000010,
0b0000110000000000011,
0b0000110000000000100,
0b0000110000000000101,
0b0000110000000000111,
0b0000110000000001001,
0b0000110000000001101,
0b0000110000000010000,
0b0000110000100000000,
0b0001000000000000000,
0b0001000000000000010,
0b0001000000000000100,
0b0001000000100000000,
0b0010110000000000000,
0b0010110000000010000,
0b0011000000000000000,
0b0011000000100000000,
0b0101000000000000000,
0b0101000000100000000
};
static const uint32_t gen7_datatype_table[32] = {
0b001000000000000001,
0b001000000000100000,
0b001000000000100001,
0b001000000001100001,
0b001000000010111101,
0b001000001011111101,
0b001000001110100001,
0b001000001110100101,
0b001000001110111101,
0b001000010000100001,
0b001000110000100000,
0b001000110000100001,
0b001001010010100101,
0b001001110010100100,
0b001001110010100101,
0b001111001110111101,
0b001111011110011101,
0b001111011110111100,
0b001111011110111101,
0b001111111110111100,
0b000000001000001100,
0b001000000000111101,
0b001000000010100101,
0b001000010000100000,
0b001001010010100100,
0b001001110010000100,
0b001010010100001001,
0b001101111110111101,
0b001111111110111101,
0b001011110110101100,
0b001010010100101000,
0b001010110100101000
};
static const uint32_t gen7_subreg_table[32] = {
0b000000000000000,
0b000000000000001,
0b000000000001000,
0b000000000001111,
0b000000000010000,
0b000000010000000,
0b000000100000000,
0b000000110000000,
0b000001000000000,
0b000001000010000,
0b000010100000000,
0b001000000000000,
0b001000000000001,
0b001000010000001,
0b001000010000010,
0b001000010000011,
0b001000010000100,
0b001000010000111,
0b001000010001000,
0b001000010001110,
0b001000010001111,
0b001000110000000,
0b001000111101000,
0b010000000000000,
0b010000110000000,
0b011000000000000,
0b011110010000111,
0b100000000000000,
0b101000000000000,
0b110000000000000,
0b111000000000000,
0b111000000011100
};
static const uint32_t gen7_src_index_table[32] = {
0b000000000000,
0b000000000010,
0b000000010000,
0b000000010010,
0b000000011000,
0b000000100000,
0b000000101000,
0b000001001000,
0b000001010000,
0b000001110000,
0b000001111000,
0b001100000000,
0b001100000010,
0b001100001000,
0b001100010000,
0b001100010010,
0b001100100000,
0b001100101000,
0b001100111000,
0b001101000000,
0b001101000010,
0b001101001000,
0b001101010000,
0b001101100000,
0b001101101000,
0b001101110000,
0b001101110001,
0b001101111000,
0b010001101000,
0b010001101001,
0b010001101010,
0b010110001000
};
static const uint32_t *control_index_table;
static const uint32_t *datatype_table;
static const uint32_t *subreg_table;
static const uint32_t *src_index_table;
static bool
set_control_index(struct intel_context *intel,
struct brw_compact_instruction *dst,
struct brw_instruction *src)
{
uint32_t *src_u32 = (uint32_t *)src;
uint32_t uncompacted = 0;
uncompacted |= ((src_u32[0] >> 8) & 0xffff) << 0;
uncompacted |= ((src_u32[0] >> 31) & 0x1) << 16;
/* On gen7, the flag register number gets integrated into the control
* index.
*/
if (intel->gen >= 7)
uncompacted |= ((src_u32[2] >> 25) & 0x3) << 17;
for (int i = 0; i < 32; i++) {
if (control_index_table[i] == uncompacted) {
dst->dw0.control_index = i;
return true;
}
}
return false;
}
static bool
set_datatype_index(struct brw_compact_instruction *dst,
struct brw_instruction *src)
{
uint32_t uncompacted = 0;
uncompacted |= src->bits1.ud & 0x7fff;
uncompacted |= (src->bits1.ud >> 29) << 15;
for (int i = 0; i < 32; i++) {
if (datatype_table[i] == uncompacted) {
dst->dw0.data_type_index = i;
return true;
}
}
return false;
}
static bool
set_subreg_index(struct brw_compact_instruction *dst,
struct brw_instruction *src)
{
uint32_t uncompacted = 0;
uncompacted |= src->bits1.da1.dest_subreg_nr << 0;
uncompacted |= src->bits2.da1.src0_subreg_nr << 5;
uncompacted |= src->bits3.da1.src1_subreg_nr << 10;
for (int i = 0; i < 32; i++) {
if (subreg_table[i] == uncompacted) {
dst->dw0.sub_reg_index = i;
return true;
}
}
return false;
}
static bool
get_src_index(uint32_t uncompacted,
uint32_t *compacted)
{
for (int i = 0; i < 32; i++) {
if (src_index_table[i] == uncompacted) {
*compacted = i;
return true;
}
}
return false;
}
static bool
set_src0_index(struct brw_compact_instruction *dst,
struct brw_instruction *src)
{
uint32_t compacted, uncompacted = 0;
uncompacted |= (src->bits2.ud >> 13) & 0xfff;
if (!get_src_index(uncompacted, &compacted))
return false;
dst->dw0.src0_index = compacted & 0x3;
dst->dw1.src0_index = compacted >> 2;
return true;
}
static bool
set_src1_index(struct brw_compact_instruction *dst,
struct brw_instruction *src)
{
uint32_t compacted, uncompacted = 0;
uncompacted |= (src->bits3.ud >> 13) & 0xfff;
if (!get_src_index(uncompacted, &compacted))
return false;
dst->dw1.src1_index = compacted;
return true;
}
/**
* Tries to compact instruction src into dst.
*
* It doesn't modify dst unless src is compactable, which is relied on by
* brw_compact_instructions().
*/
bool
brw_try_compact_instruction(struct brw_compile *p,
struct brw_compact_instruction *dst,
struct brw_instruction *src)
{
struct brw_context *brw = p->brw;
struct intel_context *intel = &brw->intel;
struct brw_compact_instruction temp;
if (src->header.opcode == BRW_OPCODE_IF ||
src->header.opcode == BRW_OPCODE_ELSE ||
src->header.opcode == BRW_OPCODE_ENDIF ||
src->header.opcode == BRW_OPCODE_HALT ||
src->header.opcode == BRW_OPCODE_DO ||
src->header.opcode == BRW_OPCODE_WHILE) {
/* FINISHME: The fixup code below, and brw_set_uip_jip and friends, needs
* to be able to handle compacted flow control instructions..
*/
return false;
}
/* FINISHME: immediates */
if (src->bits1.da1.src0_reg_file == BRW_IMMEDIATE_VALUE ||
src->bits1.da1.src1_reg_file == BRW_IMMEDIATE_VALUE)
return false;
memset(&temp, 0, sizeof(temp));
temp.dw0.opcode = src->header.opcode;
temp.dw0.debug_control = src->header.debug_control;
if (!set_control_index(intel, &temp, src))
return false;
if (!set_datatype_index(&temp, src))
return false;
if (!set_subreg_index(&temp, src))
return false;
temp.dw0.acc_wr_control = src->header.acc_wr_control;
temp.dw0.conditionalmod = src->header.destreg__conditionalmod;
if (intel->gen <= 6)
temp.dw0.flag_subreg_nr = src->bits2.da1.flag_subreg_nr;
temp.dw0.cmpt_ctrl = 1;
if (!set_src0_index(&temp, src))
return false;
if (!set_src1_index(&temp, src))
return false;
temp.dw1.dst_reg_nr = src->bits1.da1.dest_reg_nr;
temp.dw1.src0_reg_nr = src->bits2.da1.src0_reg_nr;
temp.dw1.src1_reg_nr = src->bits3.da1.src1_reg_nr;
*dst = temp;
return true;
}
static void
set_uncompacted_control(struct intel_context *intel,
struct brw_instruction *dst,
struct brw_compact_instruction *src)
{
uint32_t *dst_u32 = (uint32_t *)dst;
uint32_t uncompacted = control_index_table[src->dw0.control_index];
dst_u32[0] |= ((uncompacted >> 0) & 0xffff) << 8;
dst_u32[0] |= ((uncompacted >> 16) & 0x1) << 31;
if (intel->gen >= 7)
dst_u32[2] |= ((uncompacted >> 17) & 0x3) << 25;
}
static void
set_uncompacted_datatype(struct brw_instruction *dst,
struct brw_compact_instruction *src)
{
uint32_t uncompacted = datatype_table[src->dw0.data_type_index];
dst->bits1.ud &= ~(0x7 << 29);
dst->bits1.ud |= ((uncompacted >> 15) & 0x7) << 29;
dst->bits1.ud &= ~0x7fff;
dst->bits1.ud |= uncompacted & 0x7fff;
}
static void
set_uncompacted_subreg(struct brw_instruction *dst,
struct brw_compact_instruction *src)
{
uint32_t uncompacted = subreg_table[src->dw0.sub_reg_index];
dst->bits1.da1.dest_subreg_nr = (uncompacted >> 0) & 0x1f;
dst->bits2.da1.src0_subreg_nr = (uncompacted >> 5) & 0x1f;
dst->bits3.da1.src1_subreg_nr = (uncompacted >> 10) & 0x1f;
}
static void
set_uncompacted_src0(struct brw_instruction *dst,
struct brw_compact_instruction *src)
{
uint32_t compacted = src->dw0.src0_index | src->dw1.src0_index << 2;
uint32_t uncompacted = src_index_table[compacted];
dst->bits2.ud |= uncompacted << 13;
}
static void
set_uncompacted_src1(struct brw_instruction *dst,
struct brw_compact_instruction *src)
{
uint32_t uncompacted = src_index_table[src->dw1.src1_index];
dst->bits3.ud |= uncompacted << 13;
}
void
brw_uncompact_instruction(struct intel_context *intel,
struct brw_instruction *dst,
struct brw_compact_instruction *src)
{
memset(dst, 0, sizeof(*dst));
dst->header.opcode = src->dw0.opcode;
dst->header.debug_control = src->dw0.debug_control;
set_uncompacted_control(intel, dst, src);
set_uncompacted_datatype(dst, src);
set_uncompacted_subreg(dst, src);
dst->header.acc_wr_control = src->dw0.acc_wr_control;
dst->header.destreg__conditionalmod = src->dw0.conditionalmod;
if (intel->gen <= 6)
dst->bits2.da1.flag_subreg_nr = src->dw0.flag_subreg_nr;
set_uncompacted_src0(dst, src);
set_uncompacted_src1(dst, src);
dst->bits1.da1.dest_reg_nr = src->dw1.dst_reg_nr;
dst->bits2.da1.src0_reg_nr = src->dw1.src0_reg_nr;
dst->bits3.da1.src1_reg_nr = src->dw1.src1_reg_nr;
}
void brw_debug_compact_uncompact(struct intel_context *intel,
struct brw_instruction *orig,
struct brw_instruction *uncompacted)
{
fprintf(stderr, "Instruction compact/uncompact changed (gen%d):\n",
intel->gen);
fprintf(stderr, " before: ");
brw_disasm(stderr, orig, intel->gen);
fprintf(stderr, " after: ");
brw_disasm(stderr, uncompacted, intel->gen);
uint32_t *before_bits = (uint32_t *)orig;
uint32_t *after_bits = (uint32_t *)uncompacted;
printf(" changed bits:\n");
for (int i = 0; i < 128; i++) {
uint32_t before = before_bits[i / 32] & (1 << (i & 31));
uint32_t after = after_bits[i / 32] & (1 << (i & 31));
if (before != after) {
printf(" bit %d, %s to %s\n", i,
before ? "set" : "unset",
after ? "set" : "unset");
}
}
}
static int
compacted_between(int old_ip, int old_target_ip, int *compacted_counts)
{
int this_compacted_count = compacted_counts[old_ip];
int target_compacted_count = compacted_counts[old_target_ip];
return target_compacted_count - this_compacted_count;
}
static void
update_uip_jip(struct brw_instruction *insn, int this_old_ip,
int *compacted_counts)
{
int target_old_ip;
target_old_ip = this_old_ip + insn->bits3.break_cont.jip;
insn->bits3.break_cont.jip -= compacted_between(this_old_ip,
target_old_ip,
compacted_counts);
target_old_ip = this_old_ip + insn->bits3.break_cont.uip;
insn->bits3.break_cont.uip -= compacted_between(this_old_ip,
target_old_ip,
compacted_counts);
}
void
brw_init_compaction_tables(struct intel_context *intel)
{
assert(gen6_control_index_table[ARRAY_SIZE(gen6_control_index_table) - 1] != 0);
assert(gen6_datatype_table[ARRAY_SIZE(gen6_datatype_table) - 1] != 0);
assert(gen6_subreg_table[ARRAY_SIZE(gen6_subreg_table) - 1] != 0);
assert(gen6_src_index_table[ARRAY_SIZE(gen6_src_index_table) - 1] != 0);
assert(gen7_control_index_table[ARRAY_SIZE(gen6_control_index_table) - 1] != 0);
assert(gen7_datatype_table[ARRAY_SIZE(gen6_datatype_table) - 1] != 0);
assert(gen7_subreg_table[ARRAY_SIZE(gen6_subreg_table) - 1] != 0);
assert(gen7_src_index_table[ARRAY_SIZE(gen6_src_index_table) - 1] != 0);
switch (intel->gen) {
case 7:
control_index_table = gen7_control_index_table;
datatype_table = gen7_datatype_table;
subreg_table = gen7_subreg_table;
src_index_table = gen7_src_index_table;
break;
case 6:
control_index_table = gen6_control_index_table;
datatype_table = gen6_datatype_table;
subreg_table = gen6_subreg_table;
src_index_table = gen6_src_index_table;
break;
default:
return;
}
}
void
brw_compact_instructions(struct brw_compile *p)
{
struct brw_context *brw = p->brw;
struct intel_context *intel = &brw->intel;
void *store = p->store;
/* For an instruction at byte offset 8*i before compaction, this is the number
* of compacted instructions that preceded it.
*/
int compacted_counts[p->next_insn_offset / 8];
/* For an instruction at byte offset 8*i after compaction, this is the
* 8-byte offset it was at before compaction.
*/
int old_ip[p->next_insn_offset / 8];
if (intel->gen < 6)
return;
int src_offset;
int offset = 0;
int compacted_count = 0;
for (src_offset = 0; src_offset < p->nr_insn * 16;) {
struct brw_instruction *src = store + src_offset;
void *dst = store + offset;
old_ip[offset / 8] = src_offset / 8;
compacted_counts[src_offset / 8] = compacted_count;
struct brw_instruction saved = *src;
if (!src->header.cmpt_control &&
brw_try_compact_instruction(p, dst, src)) {
compacted_count++;
if (INTEL_DEBUG) {
struct brw_instruction uncompacted;
brw_uncompact_instruction(intel, &uncompacted, dst);
if (memcmp(&saved, &uncompacted, sizeof(uncompacted))) {
brw_debug_compact_uncompact(intel, &saved, &uncompacted);
}
}
offset += 8;
src_offset += 16;
} else {
int size = src->header.cmpt_control ? 8 : 16;
/* It appears that the end of thread SEND instruction needs to be
* aligned, or the GPU hangs.
*/
if ((src->header.opcode == BRW_OPCODE_SEND ||
src->header.opcode == BRW_OPCODE_SENDC) &&
src->bits3.generic.end_of_thread &&
(offset & 8) != 0) {
struct brw_compact_instruction *align = store + offset;
memset(align, 0, sizeof(*align));
align->dw0.opcode = BRW_OPCODE_NOP;
align->dw0.cmpt_ctrl = 1;
offset += 8;
old_ip[offset / 8] = src_offset / 8;
dst = store + offset;
}
/* If we didn't compact this intruction, we need to move it down into
* place.
*/
if (offset != src_offset) {
memmove(dst, src, size);
}
offset += size;
src_offset += size;
}
}
/* Fix up control flow offsets. */
p->next_insn_offset = offset;
for (offset = 0; offset < p->next_insn_offset;) {
struct brw_instruction *insn = store + offset;
int this_old_ip = old_ip[offset / 8];
int this_compacted_count = compacted_counts[this_old_ip];
int target_old_ip, target_compacted_count;
switch (insn->header.opcode) {
case BRW_OPCODE_BREAK:
case BRW_OPCODE_CONTINUE:
case BRW_OPCODE_HALT:
update_uip_jip(insn, this_old_ip, compacted_counts);
break;
case BRW_OPCODE_IF:
case BRW_OPCODE_ELSE:
case BRW_OPCODE_ENDIF:
case BRW_OPCODE_WHILE:
if (intel->gen == 6) {
target_old_ip = this_old_ip + insn->bits1.branch_gen6.jump_count;
target_compacted_count = compacted_counts[target_old_ip];
insn->bits1.branch_gen6.jump_count -= (target_compacted_count -
this_compacted_count);
} else {
update_uip_jip(insn, this_old_ip, compacted_counts);
}
break;
}
if (insn->header.cmpt_control) {
offset += 8;
} else {
offset += 16;
}
}
/* p->nr_insn is counting the number of uncompacted instructions still, so
* divide. We do want to be sure there's a valid instruction in any
* alignment padding, so that the next compression pass (for the FS 8/16
* compile passes) parses correctly.
*/
if (p->next_insn_offset & 8) {
struct brw_compact_instruction *align = store + offset;
memset(align, 0, sizeof(*align));
align->dw0.opcode = BRW_OPCODE_NOP;
align->dw0.cmpt_ctrl = 1;
p->next_insn_offset += 8;
}
p->nr_insn = p->next_insn_offset / 16;
if (0) {
fprintf(stdout, "dumping compacted program\n");
brw_dump_compile(p, stdout, 0, p->next_insn_offset);
int cmp = 0;
for (offset = 0; offset < p->next_insn_offset;) {
struct brw_instruction *insn = store + offset;
if (insn->header.cmpt_control) {
offset += 8;
cmp++;
} else {
offset += 16;
}
}
fprintf(stderr, "%db/%db saved (%d%%)\n", cmp * 8, offset + cmp * 8,
cmp * 8 * 100 / (offset + cmp * 8));
}
}