/*
* Copyright © 2011 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.
*/
#include "brw_vec4.h"
#include "brw_fs.h"
#include "brw_cfg.h"
#include "brw_vs.h"
#include "brw_nir.h"
#include "brw_vec4_builder.h"
#include "brw_vec4_live_variables.h"
#include "brw_dead_control_flow.h"
#include "program/prog_parameter.h"
#define MAX_INSTRUCTION (1 << 30)
using namespace brw;
namespace brw {
void
src_reg::init()
{
memset(this, 0, sizeof(*this));
this->file = BAD_FILE;
}
src_reg::src_reg(enum brw_reg_file file, int nr, const glsl_type *type)
{
init();
this->file = file;
this->nr = nr;
if (type && (type->is_scalar() || type->is_vector() || type->is_matrix()))
this->swizzle = brw_swizzle_for_size(type->vector_elements);
else
this->swizzle = BRW_SWIZZLE_XYZW;
if (type)
this->type = brw_type_for_base_type(type);
}
/** Generic unset register constructor. */
src_reg::src_reg()
{
init();
}
src_reg::src_reg(struct ::brw_reg reg) :
backend_reg(reg)
{
this->offset = 0;
this->reladdr = NULL;
}
src_reg::src_reg(const dst_reg ®) :
backend_reg(reg)
{
this->reladdr = reg.reladdr;
this->swizzle = brw_swizzle_for_mask(reg.writemask);
}
void
dst_reg::init()
{
memset(this, 0, sizeof(*this));
this->file = BAD_FILE;
this->writemask = WRITEMASK_XYZW;
}
dst_reg::dst_reg()
{
init();
}
dst_reg::dst_reg(enum brw_reg_file file, int nr)
{
init();
this->file = file;
this->nr = nr;
}
dst_reg::dst_reg(enum brw_reg_file file, int nr, const glsl_type *type,
unsigned writemask)
{
init();
this->file = file;
this->nr = nr;
this->type = brw_type_for_base_type(type);
this->writemask = writemask;
}
dst_reg::dst_reg(enum brw_reg_file file, int nr, brw_reg_type type,
unsigned writemask)
{
init();
this->file = file;
this->nr = nr;
this->type = type;
this->writemask = writemask;
}
dst_reg::dst_reg(struct ::brw_reg reg) :
backend_reg(reg)
{
this->offset = 0;
this->reladdr = NULL;
}
dst_reg::dst_reg(const src_reg ®) :
backend_reg(reg)
{
this->writemask = brw_mask_for_swizzle(reg.swizzle);
this->reladdr = reg.reladdr;
}
bool
dst_reg::equals(const dst_reg &r) const
{
return (this->backend_reg::equals(r) &&
(reladdr == r.reladdr ||
(reladdr && r.reladdr && reladdr->equals(*r.reladdr))));
}
bool
vec4_instruction::is_send_from_grf()
{
switch (opcode) {
case SHADER_OPCODE_SHADER_TIME_ADD:
case VS_OPCODE_PULL_CONSTANT_LOAD_GEN7:
case SHADER_OPCODE_UNTYPED_ATOMIC:
case SHADER_OPCODE_UNTYPED_SURFACE_READ:
case SHADER_OPCODE_UNTYPED_SURFACE_WRITE:
case SHADER_OPCODE_TYPED_ATOMIC:
case SHADER_OPCODE_TYPED_SURFACE_READ:
case SHADER_OPCODE_TYPED_SURFACE_WRITE:
case VEC4_OPCODE_URB_READ:
case TCS_OPCODE_URB_WRITE:
case TCS_OPCODE_RELEASE_INPUT:
case SHADER_OPCODE_BARRIER:
return true;
default:
return false;
}
}
/**
* Returns true if this instruction's sources and destinations cannot
* safely be the same register.
*
* In most cases, a register can be written over safely by the same
* instruction that is its last use. For a single instruction, the
* sources are dereferenced before writing of the destination starts
* (naturally).
*
* However, there are a few cases where this can be problematic:
*
* - Virtual opcodes that translate to multiple instructions in the
* code generator: if src == dst and one instruction writes the
* destination before a later instruction reads the source, then
* src will have been clobbered.
*
* The register allocator uses this information to set up conflicts between
* GRF sources and the destination.
*/
bool
vec4_instruction::has_source_and_destination_hazard() const
{
switch (opcode) {
case TCS_OPCODE_SET_INPUT_URB_OFFSETS:
case TCS_OPCODE_SET_OUTPUT_URB_OFFSETS:
case TES_OPCODE_ADD_INDIRECT_URB_OFFSET:
return true;
default:
/* 8-wide compressed DF operations are executed as two 4-wide operations,
* so we have a src/dst hazard if the first half of the instruction
* overwrites the source of the second half. Prevent this by marking
* compressed instructions as having src/dst hazards, so the register
* allocator assigns safe register regions for dst and srcs.
*/
return size_written > REG_SIZE;
}
}
unsigned
vec4_instruction::size_read(unsigned arg) const
{
switch (opcode) {
case SHADER_OPCODE_SHADER_TIME_ADD:
case SHADER_OPCODE_UNTYPED_ATOMIC:
case SHADER_OPCODE_UNTYPED_SURFACE_READ:
case SHADER_OPCODE_UNTYPED_SURFACE_WRITE:
case SHADER_OPCODE_TYPED_ATOMIC:
case SHADER_OPCODE_TYPED_SURFACE_READ:
case SHADER_OPCODE_TYPED_SURFACE_WRITE:
case TCS_OPCODE_URB_WRITE:
if (arg == 0)
return mlen * REG_SIZE;
break;
case VS_OPCODE_PULL_CONSTANT_LOAD_GEN7:
if (arg == 1)
return mlen * REG_SIZE;
break;
default:
break;
}
switch (src[arg].file) {
case BAD_FILE:
return 0;
case IMM:
case UNIFORM:
return 4 * type_sz(src[arg].type);
default:
/* XXX - Represent actual vertical stride. */
return exec_size * type_sz(src[arg].type);
}
}
bool
vec4_instruction::can_do_source_mods(const struct gen_device_info *devinfo)
{
if (devinfo->gen == 6 && is_math())
return false;
if (is_send_from_grf())
return false;
if (!backend_instruction::can_do_source_mods())
return false;
return true;
}
bool
vec4_instruction::can_do_writemask(const struct gen_device_info *devinfo)
{
switch (opcode) {
case SHADER_OPCODE_GEN4_SCRATCH_READ:
case VEC4_OPCODE_FROM_DOUBLE:
case VEC4_OPCODE_TO_DOUBLE:
case VEC4_OPCODE_PICK_LOW_32BIT:
case VEC4_OPCODE_PICK_HIGH_32BIT:
case VEC4_OPCODE_SET_LOW_32BIT:
case VEC4_OPCODE_SET_HIGH_32BIT:
case VS_OPCODE_PULL_CONSTANT_LOAD:
case VS_OPCODE_PULL_CONSTANT_LOAD_GEN7:
case VS_OPCODE_SET_SIMD4X2_HEADER_GEN9:
case TCS_OPCODE_SET_INPUT_URB_OFFSETS:
case TCS_OPCODE_SET_OUTPUT_URB_OFFSETS:
case TES_OPCODE_CREATE_INPUT_READ_HEADER:
case TES_OPCODE_ADD_INDIRECT_URB_OFFSET:
case VEC4_OPCODE_URB_READ:
case SHADER_OPCODE_MOV_INDIRECT:
return false;
default:
/* The MATH instruction on Gen6 only executes in align1 mode, which does
* not support writemasking.
*/
if (devinfo->gen == 6 && is_math())
return false;
if (is_tex())
return false;
return true;
}
}
bool
vec4_instruction::can_change_types() const
{
return dst.type == src[0].type &&
!src[0].abs && !src[0].negate && !saturate &&
(opcode == BRW_OPCODE_MOV ||
(opcode == BRW_OPCODE_SEL &&
dst.type == src[1].type &&
predicate != BRW_PREDICATE_NONE &&
!src[1].abs && !src[1].negate));
}
/**
* Returns how many MRFs an opcode will write over.
*
* Note that this is not the 0 or 1 implied writes in an actual gen
* instruction -- the generate_* functions generate additional MOVs
* for setup.
*/
int
vec4_visitor::implied_mrf_writes(vec4_instruction *inst)
{
if (inst->mlen == 0 || inst->is_send_from_grf())
return 0;
switch (inst->opcode) {
case SHADER_OPCODE_RCP:
case SHADER_OPCODE_RSQ:
case SHADER_OPCODE_SQRT:
case SHADER_OPCODE_EXP2:
case SHADER_OPCODE_LOG2:
case SHADER_OPCODE_SIN:
case SHADER_OPCODE_COS:
return 1;
case SHADER_OPCODE_INT_QUOTIENT:
case SHADER_OPCODE_INT_REMAINDER:
case SHADER_OPCODE_POW:
case TCS_OPCODE_THREAD_END:
return 2;
case VS_OPCODE_URB_WRITE:
return 1;
case VS_OPCODE_PULL_CONSTANT_LOAD:
return 2;
case SHADER_OPCODE_GEN4_SCRATCH_READ:
return 2;
case SHADER_OPCODE_GEN4_SCRATCH_WRITE:
return 3;
case GS_OPCODE_URB_WRITE:
case GS_OPCODE_URB_WRITE_ALLOCATE:
case GS_OPCODE_THREAD_END:
return 0;
case GS_OPCODE_FF_SYNC:
return 1;
case TCS_OPCODE_URB_WRITE:
return 0;
case SHADER_OPCODE_SHADER_TIME_ADD:
return 0;
case SHADER_OPCODE_TEX:
case SHADER_OPCODE_TXL:
case SHADER_OPCODE_TXD:
case SHADER_OPCODE_TXF:
case SHADER_OPCODE_TXF_CMS:
case SHADER_OPCODE_TXF_CMS_W:
case SHADER_OPCODE_TXF_MCS:
case SHADER_OPCODE_TXS:
case SHADER_OPCODE_TG4:
case SHADER_OPCODE_TG4_OFFSET:
case SHADER_OPCODE_SAMPLEINFO:
case VS_OPCODE_GET_BUFFER_SIZE:
return inst->header_size;
default:
unreachable("not reached");
}
}
bool
src_reg::equals(const src_reg &r) const
{
return (this->backend_reg::equals(r) &&
!reladdr && !r.reladdr);
}
bool
vec4_visitor::opt_vector_float()
{
bool progress = false;
foreach_block(block, cfg) {
int last_reg = -1, last_offset = -1;
enum brw_reg_file last_reg_file = BAD_FILE;
uint8_t imm[4] = { 0 };
int inst_count = 0;
vec4_instruction *imm_inst[4];
unsigned writemask = 0;
enum brw_reg_type dest_type = BRW_REGISTER_TYPE_F;
foreach_inst_in_block_safe(vec4_instruction, inst, block) {
int vf = -1;
enum brw_reg_type need_type;
/* Look for unconditional MOVs from an immediate with a partial
* writemask. Skip type-conversion MOVs other than integer 0,
* where the type doesn't matter. See if the immediate can be
* represented as a VF.
*/
if (inst->opcode == BRW_OPCODE_MOV &&
inst->src[0].file == IMM &&
inst->predicate == BRW_PREDICATE_NONE &&
inst->dst.writemask != WRITEMASK_XYZW &&
type_sz(inst->src[0].type) < 8 &&
(inst->src[0].type == inst->dst.type || inst->src[0].d == 0)) {
vf = brw_float_to_vf(inst->src[0].d);
need_type = BRW_REGISTER_TYPE_D;
if (vf == -1) {
vf = brw_float_to_vf(inst->src[0].f);
need_type = BRW_REGISTER_TYPE_F;
}
} else {
last_reg = -1;
}
/* If this wasn't a MOV, or the destination register doesn't match,
* or we have to switch destination types, then this breaks our
* sequence. Combine anything we've accumulated so far.
*/
if (last_reg != inst->dst.nr ||
last_offset != inst->dst.offset ||
last_reg_file != inst->dst.file ||
(vf > 0 && dest_type != need_type)) {
if (inst_count > 1) {
unsigned vf;
memcpy(&vf, imm, sizeof(vf));
vec4_instruction *mov = MOV(imm_inst[0]->dst, brw_imm_vf(vf));
mov->dst.type = dest_type;
mov->dst.writemask = writemask;
inst->insert_before(block, mov);
for (int i = 0; i < inst_count; i++) {
imm_inst[i]->remove(block);
}
progress = true;
}
inst_count = 0;
last_reg = -1;
writemask = 0;
dest_type = BRW_REGISTER_TYPE_F;
for (int i = 0; i < 4; i++) {
imm[i] = 0;
}
}
/* Record this instruction's value (if it was representable). */
if (vf != -1) {
if ((inst->dst.writemask & WRITEMASK_X) != 0)
imm[0] = vf;
if ((inst->dst.writemask & WRITEMASK_Y) != 0)
imm[1] = vf;
if ((inst->dst.writemask & WRITEMASK_Z) != 0)
imm[2] = vf;
if ((inst->dst.writemask & WRITEMASK_W) != 0)
imm[3] = vf;
writemask |= inst->dst.writemask;
imm_inst[inst_count++] = inst;
last_reg = inst->dst.nr;
last_offset = inst->dst.offset;
last_reg_file = inst->dst.file;
if (vf > 0)
dest_type = need_type;
}
}
}
if (progress)
invalidate_live_intervals();
return progress;
}
/* Replaces unused channels of a swizzle with channels that are used.
*
* For instance, this pass transforms
*
* mov vgrf4.yz, vgrf5.wxzy
*
* into
*
* mov vgrf4.yz, vgrf5.xxzx
*
* This eliminates false uses of some channels, letting dead code elimination
* remove the instructions that wrote them.
*/
bool
vec4_visitor::opt_reduce_swizzle()
{
bool progress = false;
foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) {
if (inst->dst.file == BAD_FILE ||
inst->dst.file == ARF ||
inst->dst.file == FIXED_GRF ||
inst->is_send_from_grf())
continue;
unsigned swizzle;
/* Determine which channels of the sources are read. */
switch (inst->opcode) {
case VEC4_OPCODE_PACK_BYTES:
case BRW_OPCODE_DP4:
case BRW_OPCODE_DPH: /* FINISHME: DPH reads only three channels of src0,
* but all four of src1.
*/
swizzle = brw_swizzle_for_size(4);
break;
case BRW_OPCODE_DP3:
swizzle = brw_swizzle_for_size(3);
break;
case BRW_OPCODE_DP2:
swizzle = brw_swizzle_for_size(2);
break;
case VEC4_OPCODE_TO_DOUBLE:
case VEC4_OPCODE_FROM_DOUBLE:
case VEC4_OPCODE_PICK_LOW_32BIT:
case VEC4_OPCODE_PICK_HIGH_32BIT:
case VEC4_OPCODE_SET_LOW_32BIT:
case VEC4_OPCODE_SET_HIGH_32BIT:
swizzle = brw_swizzle_for_size(4);
break;
default:
swizzle = brw_swizzle_for_mask(inst->dst.writemask);
break;
}
/* Update sources' swizzles. */
for (int i = 0; i < 3; i++) {
if (inst->src[i].file != VGRF &&
inst->src[i].file != ATTR &&
inst->src[i].file != UNIFORM)
continue;
const unsigned new_swizzle =
brw_compose_swizzle(swizzle, inst->src[i].swizzle);
if (inst->src[i].swizzle != new_swizzle) {
inst->src[i].swizzle = new_swizzle;
progress = true;
}
}
}
if (progress)
invalidate_live_intervals();
return progress;
}
void
vec4_visitor::split_uniform_registers()
{
/* Prior to this, uniforms have been in an array sized according to
* the number of vector uniforms present, sparsely filled (so an
* aggregate results in reg indices being skipped over). Now we're
* going to cut those aggregates up so each .nr index is one
* vector. The goal is to make elimination of unused uniform
* components easier later.
*/
foreach_block_and_inst(block, vec4_instruction, inst, cfg) {
for (int i = 0 ; i < 3; i++) {
if (inst->src[i].file != UNIFORM)
continue;
assert(!inst->src[i].reladdr);
inst->src[i].nr += inst->src[i].offset / 16;
inst->src[i].offset %= 16;
}
}
}
void
vec4_visitor::pack_uniform_registers()
{
uint8_t chans_used[this->uniforms];
int new_loc[this->uniforms];
int new_chan[this->uniforms];
memset(chans_used, 0, sizeof(chans_used));
memset(new_loc, 0, sizeof(new_loc));
memset(new_chan, 0, sizeof(new_chan));
/* Find which uniform vectors are actually used by the program. We
* expect unused vector elements when we've moved array access out
* to pull constants, and from some GLSL code generators like wine.
*/
foreach_block_and_inst(block, vec4_instruction, inst, cfg) {
unsigned readmask;
switch (inst->opcode) {
case VEC4_OPCODE_PACK_BYTES:
case BRW_OPCODE_DP4:
case BRW_OPCODE_DPH:
readmask = 0xf;
break;
case BRW_OPCODE_DP3:
readmask = 0x7;
break;
case BRW_OPCODE_DP2:
readmask = 0x3;
break;
default:
readmask = inst->dst.writemask;
break;
}
for (int i = 0 ; i < 3; i++) {
if (inst->src[i].file != UNIFORM)
continue;
assert(type_sz(inst->src[i].type) % 4 == 0);
unsigned channel_size = type_sz(inst->src[i].type) / 4;
int reg = inst->src[i].nr;
for (int c = 0; c < 4; c++) {
if (!(readmask & (1 << c)))
continue;
unsigned channel = BRW_GET_SWZ(inst->src[i].swizzle, c) + 1;
unsigned used = MAX2(chans_used[reg], channel * channel_size);
if (used <= 4)
chans_used[reg] = used;
else
chans_used[reg + 1] = used - 4;
}
}
if (inst->opcode == SHADER_OPCODE_MOV_INDIRECT &&
inst->src[0].file == UNIFORM) {
assert(inst->src[2].file == BRW_IMMEDIATE_VALUE);
assert(inst->src[0].subnr == 0);
unsigned bytes_read = inst->src[2].ud;
assert(bytes_read % 4 == 0);
unsigned vec4s_read = DIV_ROUND_UP(bytes_read, 16);
/* We just mark every register touched by a MOV_INDIRECT as being
* fully used. This ensures that it doesn't broken up piecewise by
* the next part of our packing algorithm.
*/
int reg = inst->src[0].nr;
for (unsigned i = 0; i < vec4s_read; i++)
chans_used[reg + i] = 4;
}
}
int new_uniform_count = 0;
/* Now, figure out a packing of the live uniform vectors into our
* push constants.
*/
for (int src = 0; src < uniforms; src++) {
int size = chans_used[src];
if (size == 0)
continue;
int dst;
/* Find the lowest place we can slot this uniform in. */
for (dst = 0; dst < src; dst++) {
if (chans_used[dst] + size <= 4)
break;
}
if (src == dst) {
new_loc[src] = dst;
new_chan[src] = 0;
} else {
new_loc[src] = dst;
new_chan[src] = chans_used[dst];
/* Move the references to the data */
for (int j = 0; j < size; j++) {
stage_prog_data->param[dst * 4 + new_chan[src] + j] =
stage_prog_data->param[src * 4 + j];
}
chans_used[dst] += size;
chans_used[src] = 0;
}
new_uniform_count = MAX2(new_uniform_count, dst + 1);
}
this->uniforms = new_uniform_count;
/* Now, update the instructions for our repacked uniforms. */
foreach_block_and_inst(block, vec4_instruction, inst, cfg) {
for (int i = 0 ; i < 3; i++) {
int src = inst->src[i].nr;
if (inst->src[i].file != UNIFORM)
continue;
inst->src[i].nr = new_loc[src];
inst->src[i].swizzle += BRW_SWIZZLE4(new_chan[src], new_chan[src],
new_chan[src], new_chan[src]);
}
}
}
/**
* Does algebraic optimizations (0 * a = 0, 1 * a = a, a + 0 = a).
*
* While GLSL IR also performs this optimization, we end up with it in
* our instruction stream for a couple of reasons. One is that we
* sometimes generate silly instructions, for example in array access
* where we'll generate "ADD offset, index, base" even if base is 0.
* The other is that GLSL IR's constant propagation doesn't track the
* components of aggregates, so some VS patterns (initialize matrix to
* 0, accumulate in vertex blending factors) end up breaking down to
* instructions involving 0.
*/
bool
vec4_visitor::opt_algebraic()
{
bool progress = false;
foreach_block_and_inst(block, vec4_instruction, inst, cfg) {
switch (inst->opcode) {
case BRW_OPCODE_MOV:
if (inst->src[0].file != IMM)
break;
if (inst->saturate) {
if (inst->dst.type != inst->src[0].type)
assert(!"unimplemented: saturate mixed types");
if (brw_saturate_immediate(inst->dst.type,
&inst->src[0].as_brw_reg())) {
inst->saturate = false;
progress = true;
}
}
break;
case VEC4_OPCODE_UNPACK_UNIFORM:
if (inst->src[0].file != UNIFORM) {
inst->opcode = BRW_OPCODE_MOV;
progress = true;
}
break;
case BRW_OPCODE_ADD:
if (inst->src[1].is_zero()) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[1] = src_reg();
progress = true;
}
break;
case BRW_OPCODE_MUL:
if (inst->src[1].is_zero()) {
inst->opcode = BRW_OPCODE_MOV;
switch (inst->src[0].type) {
case BRW_REGISTER_TYPE_F:
inst->src[0] = brw_imm_f(0.0f);
break;
case BRW_REGISTER_TYPE_D:
inst->src[0] = brw_imm_d(0);
break;
case BRW_REGISTER_TYPE_UD:
inst->src[0] = brw_imm_ud(0u);
break;
default:
unreachable("not reached");
}
inst->src[1] = src_reg();
progress = true;
} else if (inst->src[1].is_one()) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[1] = src_reg();
progress = true;
} else if (inst->src[1].is_negative_one()) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[0].negate = !inst->src[0].negate;
inst->src[1] = src_reg();
progress = true;
}
break;
case BRW_OPCODE_CMP:
if (inst->conditional_mod == BRW_CONDITIONAL_GE &&
inst->src[0].abs &&
inst->src[0].negate &&
inst->src[1].is_zero()) {
inst->src[0].abs = false;
inst->src[0].negate = false;
inst->conditional_mod = BRW_CONDITIONAL_Z;
progress = true;
break;
}
break;
case SHADER_OPCODE_BROADCAST:
if (is_uniform(inst->src[0]) ||
inst->src[1].is_zero()) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[1] = src_reg();
inst->force_writemask_all = true;
progress = true;
}
break;
default:
break;
}
}
if (progress)
invalidate_live_intervals();
return progress;
}
/**
* Only a limited number of hardware registers may be used for push
* constants, so this turns access to the overflowed constants into
* pull constants.
*/
void
vec4_visitor::move_push_constants_to_pull_constants()
{
int pull_constant_loc[this->uniforms];
/* Only allow 32 registers (256 uniform components) as push constants,
* which is the limit on gen6.
*
* If changing this value, note the limitation about total_regs in
* brw_curbe.c.
*/
int max_uniform_components = 32 * 8;
if (this->uniforms * 4 <= max_uniform_components)
return;
/* Make some sort of choice as to which uniforms get sent to pull
* constants. We could potentially do something clever here like
* look for the most infrequently used uniform vec4s, but leave
* that for later.
*/
for (int i = 0; i < this->uniforms * 4; i += 4) {
pull_constant_loc[i / 4] = -1;
if (i >= max_uniform_components) {
const gl_constant_value **values = &stage_prog_data->param[i];
/* Try to find an existing copy of this uniform in the pull
* constants if it was part of an array access already.
*/
for (unsigned int j = 0; j < stage_prog_data->nr_pull_params; j += 4) {
int matches;
for (matches = 0; matches < 4; matches++) {
if (stage_prog_data->pull_param[j + matches] != values[matches])
break;
}
if (matches == 4) {
pull_constant_loc[i / 4] = j / 4;
break;
}
}
if (pull_constant_loc[i / 4] == -1) {
assert(stage_prog_data->nr_pull_params % 4 == 0);
pull_constant_loc[i / 4] = stage_prog_data->nr_pull_params / 4;
for (int j = 0; j < 4; j++) {
stage_prog_data->pull_param[stage_prog_data->nr_pull_params++] =
values[j];
}
}
}
}
/* Now actually rewrite usage of the things we've moved to pull
* constants.
*/
foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) {
for (int i = 0 ; i < 3; i++) {
if (inst->src[i].file != UNIFORM ||
pull_constant_loc[inst->src[i].nr] == -1)
continue;
int uniform = inst->src[i].nr;
const glsl_type *temp_type = type_sz(inst->src[i].type) == 8 ?
glsl_type::dvec4_type : glsl_type::vec4_type;
dst_reg temp = dst_reg(this, temp_type);
emit_pull_constant_load(block, inst, temp, inst->src[i],
pull_constant_loc[uniform], src_reg());
inst->src[i].file = temp.file;
inst->src[i].nr = temp.nr;
inst->src[i].offset %= 16;
inst->src[i].reladdr = NULL;
}
}
/* Repack push constants to remove the now-unused ones. */
pack_uniform_registers();
}
/* Conditions for which we want to avoid setting the dependency control bits */
bool
vec4_visitor::is_dep_ctrl_unsafe(const vec4_instruction *inst)
{
#define IS_DWORD(reg) \
(reg.type == BRW_REGISTER_TYPE_UD || \
reg.type == BRW_REGISTER_TYPE_D)
#define IS_64BIT(reg) (reg.file != BAD_FILE && type_sz(reg.type) == 8)
/* From the Cherryview and Broadwell PRMs:
*
* "When source or destination datatype is 64b or operation is integer DWord
* multiply, DepCtrl must not be used."
*
* SKL PRMs don't include this restriction, however, gen7 seems to be
* affected, at least by the 64b restriction, since DepCtrl with double
* precision instructions seems to produce GPU hangs in some cases.
*/
if (devinfo->gen == 8 || devinfo->is_broxton) {
if (inst->opcode == BRW_OPCODE_MUL &&
IS_DWORD(inst->src[0]) &&
IS_DWORD(inst->src[1]))
return true;
}
if (devinfo->gen >= 7 && devinfo->gen <= 8) {
if (IS_64BIT(inst->dst) || IS_64BIT(inst->src[0]) ||
IS_64BIT(inst->src[1]) || IS_64BIT(inst->src[2]))
return true;
}
#undef IS_64BIT
#undef IS_DWORD
if (devinfo->gen >= 8) {
if (inst->opcode == BRW_OPCODE_F32TO16)
return true;
}
/*
* mlen:
* In the presence of send messages, totally interrupt dependency
* control. They're long enough that the chance of dependency
* control around them just doesn't matter.
*
* predicate:
* From the Ivy Bridge PRM, volume 4 part 3.7, page 80:
* When a sequence of NoDDChk and NoDDClr are used, the last instruction that
* completes the scoreboard clear must have a non-zero execution mask. This
* means, if any kind of predication can change the execution mask or channel
* enable of the last instruction, the optimization must be avoided. This is
* to avoid instructions being shot down the pipeline when no writes are
* required.
*
* math:
* Dependency control does not work well over math instructions.
* NB: Discovered empirically
*/
return (inst->mlen || inst->predicate || inst->is_math());
}
/**
* Sets the dependency control fields on instructions after register
* allocation and before the generator is run.
*
* When you have a sequence of instructions like:
*
* DP4 temp.x vertex uniform[0]
* DP4 temp.y vertex uniform[0]
* DP4 temp.z vertex uniform[0]
* DP4 temp.w vertex uniform[0]
*
* The hardware doesn't know that it can actually run the later instructions
* while the previous ones are in flight, producing stalls. However, we have
* manual fields we can set in the instructions that let it do so.
*/
void
vec4_visitor::opt_set_dependency_control()
{
vec4_instruction *last_grf_write[BRW_MAX_GRF];
uint8_t grf_channels_written[BRW_MAX_GRF];
vec4_instruction *last_mrf_write[BRW_MAX_GRF];
uint8_t mrf_channels_written[BRW_MAX_GRF];
assert(prog_data->total_grf ||
!"Must be called after register allocation");
foreach_block (block, cfg) {
memset(last_grf_write, 0, sizeof(last_grf_write));
memset(last_mrf_write, 0, sizeof(last_mrf_write));
foreach_inst_in_block (vec4_instruction, inst, block) {
/* If we read from a register that we were doing dependency control
* on, don't do dependency control across the read.
*/
for (int i = 0; i < 3; i++) {
int reg = inst->src[i].nr + inst->src[i].offset / REG_SIZE;
if (inst->src[i].file == VGRF) {
last_grf_write[reg] = NULL;
} else if (inst->src[i].file == FIXED_GRF) {
memset(last_grf_write, 0, sizeof(last_grf_write));
break;
}
assert(inst->src[i].file != MRF);
}
if (is_dep_ctrl_unsafe(inst)) {
memset(last_grf_write, 0, sizeof(last_grf_write));
memset(last_mrf_write, 0, sizeof(last_mrf_write));
continue;
}
/* Now, see if we can do dependency control for this instruction
* against a previous one writing to its destination.
*/
int reg = inst->dst.nr + inst->dst.offset / REG_SIZE;
if (inst->dst.file == VGRF || inst->dst.file == FIXED_GRF) {
if (last_grf_write[reg] &&
last_grf_write[reg]->dst.offset == inst->dst.offset &&
!(inst->dst.writemask & grf_channels_written[reg])) {
last_grf_write[reg]->no_dd_clear = true;
inst->no_dd_check = true;
} else {
grf_channels_written[reg] = 0;
}
last_grf_write[reg] = inst;
grf_channels_written[reg] |= inst->dst.writemask;
} else if (inst->dst.file == MRF) {
if (last_mrf_write[reg] &&
last_mrf_write[reg]->dst.offset == inst->dst.offset &&
!(inst->dst.writemask & mrf_channels_written[reg])) {
last_mrf_write[reg]->no_dd_clear = true;
inst->no_dd_check = true;
} else {
mrf_channels_written[reg] = 0;
}
last_mrf_write[reg] = inst;
mrf_channels_written[reg] |= inst->dst.writemask;
}
}
}
}
bool
vec4_instruction::can_reswizzle(const struct gen_device_info *devinfo,
int dst_writemask,
int swizzle,
int swizzle_mask)
{
/* Gen6 MATH instructions can not execute in align16 mode, so swizzles
* are not allowed.
*/
if (devinfo->gen == 6 && is_math() && swizzle != BRW_SWIZZLE_XYZW)
return false;
if (!can_do_writemask(devinfo) && dst_writemask != WRITEMASK_XYZW)
return false;
/* If this instruction sets anything not referenced by swizzle, then we'd
* totally break it when we reswizzle.
*/
if (dst.writemask & ~swizzle_mask)
return false;
if (mlen > 0)
return false;
for (int i = 0; i < 3; i++) {
if (src[i].is_accumulator())
return false;
}
return true;
}
/**
* For any channels in the swizzle's source that were populated by this
* instruction, rewrite the instruction to put the appropriate result directly
* in those channels.
*
* e.g. for swizzle=yywx, MUL a.xy b c -> MUL a.yy_x b.yy z.yy_x
*/
void
vec4_instruction::reswizzle(int dst_writemask, int swizzle)
{
/* Destination write mask doesn't correspond to source swizzle for the dot
* product and pack_bytes instructions.
*/
if (opcode != BRW_OPCODE_DP4 && opcode != BRW_OPCODE_DPH &&
opcode != BRW_OPCODE_DP3 && opcode != BRW_OPCODE_DP2 &&
opcode != VEC4_OPCODE_PACK_BYTES) {
for (int i = 0; i < 3; i++) {
if (src[i].file == BAD_FILE || src[i].file == IMM)
continue;
src[i].swizzle = brw_compose_swizzle(swizzle, src[i].swizzle);
}
}
/* Apply the specified swizzle and writemask to the original mask of
* written components.
*/
dst.writemask = dst_writemask &
brw_apply_swizzle_to_mask(swizzle, dst.writemask);
}
/*
* Tries to reduce extra MOV instructions by taking temporary GRFs that get
* just written and then MOVed into another reg and making the original write
* of the GRF write directly to the final destination instead.
*/
bool
vec4_visitor::opt_register_coalesce()
{
bool progress = false;
int next_ip = 0;
calculate_live_intervals();
foreach_block_and_inst_safe (block, vec4_instruction, inst, cfg) {
int ip = next_ip;
next_ip++;
if (inst->opcode != BRW_OPCODE_MOV ||
(inst->dst.file != VGRF && inst->dst.file != MRF) ||
inst->predicate ||
inst->src[0].file != VGRF ||
inst->dst.type != inst->src[0].type ||
inst->src[0].abs || inst->src[0].negate || inst->src[0].reladdr)
continue;
/* Remove no-op MOVs */
if (inst->dst.file == inst->src[0].file &&
inst->dst.nr == inst->src[0].nr &&
inst->dst.offset == inst->src[0].offset) {
bool is_nop_mov = true;
for (unsigned c = 0; c < 4; c++) {
if ((inst->dst.writemask & (1 << c)) == 0)
continue;
if (BRW_GET_SWZ(inst->src[0].swizzle, c) != c) {
is_nop_mov = false;
break;
}
}
if (is_nop_mov) {
inst->remove(block);
progress = true;
continue;
}
}
bool to_mrf = (inst->dst.file == MRF);
/* Can't coalesce this GRF if someone else was going to
* read it later.
*/
if (var_range_end(var_from_reg(alloc, dst_reg(inst->src[0])), 8) > ip)
continue;
/* We need to check interference with the final destination between this
* instruction and the earliest instruction involved in writing the GRF
* we're eliminating. To do that, keep track of which of our source
* channels we've seen initialized.
*/
const unsigned chans_needed =
brw_apply_inv_swizzle_to_mask(inst->src[0].swizzle,
inst->dst.writemask);
unsigned chans_remaining = chans_needed;
/* Now walk up the instruction stream trying to see if we can rewrite
* everything writing to the temporary to write into the destination
* instead.
*/
vec4_instruction *_scan_inst = (vec4_instruction *)inst->prev;
foreach_inst_in_block_reverse_starting_from(vec4_instruction, scan_inst,
inst) {
_scan_inst = scan_inst;
if (regions_overlap(inst->src[0], inst->size_read(0),
scan_inst->dst, scan_inst->size_written)) {
/* Found something writing to the reg we want to coalesce away. */
if (to_mrf) {
/* SEND instructions can't have MRF as a destination. */
if (scan_inst->mlen)
break;
if (devinfo->gen == 6) {
/* gen6 math instructions must have the destination be
* VGRF, so no compute-to-MRF for them.
*/
if (scan_inst->is_math()) {
break;
}
}
}
/* This doesn't handle saturation on the instruction we
* want to coalesce away if the register types do not match.
* But if scan_inst is a non type-converting 'mov', we can fix
* the types later.
*/
if (inst->saturate &&
inst->dst.type != scan_inst->dst.type &&
!(scan_inst->opcode == BRW_OPCODE_MOV &&
scan_inst->dst.type == scan_inst->src[0].type))
break;
/* Only allow coalescing between registers of the same type size.
* Otherwise we would need to make the pass aware of the fact that
* channel sizes are different for single and double precision.
*/
if (type_sz(inst->src[0].type) != type_sz(scan_inst->src[0].type))
break;
/* Check that scan_inst writes the same amount of data as the
* instruction, otherwise coalescing would lead to writing a
* different (larger or smaller) region of the destination
*/
if (scan_inst->size_written != inst->size_written)
break;
/* If we can't handle the swizzle, bail. */
if (!scan_inst->can_reswizzle(devinfo, inst->dst.writemask,
inst->src[0].swizzle,
chans_needed)) {
break;
}
/* This only handles coalescing writes of 8 channels (1 register
* for single-precision and 2 registers for double-precision)
* starting at the source offset of the copy instruction.
*/
if (DIV_ROUND_UP(scan_inst->size_written,
type_sz(scan_inst->dst.type)) > 8 ||
scan_inst->dst.offset != inst->src[0].offset)
break;
/* Mark which channels we found unconditional writes for. */
if (!scan_inst->predicate)
chans_remaining &= ~scan_inst->dst.writemask;
if (chans_remaining == 0)
break;
}
/* You can't read from an MRF, so if someone else reads our MRF's
* source GRF that we wanted to rewrite, that stops us. If it's a
* GRF we're trying to coalesce to, we don't actually handle
* rewriting sources so bail in that case as well.
*/
bool interfered = false;
for (int i = 0; i < 3; i++) {
if (regions_overlap(inst->src[0], inst->size_read(0),
scan_inst->src[i], scan_inst->size_read(i)))
interfered = true;
}
if (interfered)
break;
/* If somebody else writes the same channels of our destination here,
* we can't coalesce before that.
*/
if (regions_overlap(inst->dst, inst->size_written,
scan_inst->dst, scan_inst->size_written) &&
(inst->dst.writemask & scan_inst->dst.writemask) != 0) {
break;
}
/* Check for reads of the register we're trying to coalesce into. We
* can't go rewriting instructions above that to put some other value
* in the register instead.
*/
if (to_mrf && scan_inst->mlen > 0) {
if (inst->dst.nr >= scan_inst->base_mrf &&
inst->dst.nr < scan_inst->base_mrf + scan_inst->mlen) {
break;
}
} else {
for (int i = 0; i < 3; i++) {
if (regions_overlap(inst->dst, inst->size_written,
scan_inst->src[i], scan_inst->size_read(i)))
interfered = true;
}
if (interfered)
break;
}
}
if (chans_remaining == 0) {
/* If we've made it here, we have an MOV we want to coalesce out, and
* a scan_inst pointing to the earliest instruction involved in
* computing the value. Now go rewrite the instruction stream
* between the two.
*/
vec4_instruction *scan_inst = _scan_inst;
while (scan_inst != inst) {
if (scan_inst->dst.file == VGRF &&
scan_inst->dst.nr == inst->src[0].nr &&
scan_inst->dst.offset == inst->src[0].offset) {
scan_inst->reswizzle(inst->dst.writemask,
inst->src[0].swizzle);
scan_inst->dst.file = inst->dst.file;
scan_inst->dst.nr = inst->dst.nr;
scan_inst->dst.offset = inst->dst.offset;
if (inst->saturate &&
inst->dst.type != scan_inst->dst.type) {
/* If we have reached this point, scan_inst is a non
* type-converting 'mov' and we can modify its register types
* to match the ones in inst. Otherwise, we could have an
* incorrect saturation result.
*/
scan_inst->dst.type = inst->dst.type;
scan_inst->src[0].type = inst->src[0].type;
}
scan_inst->saturate |= inst->saturate;
}
scan_inst = (vec4_instruction *)scan_inst->next;
}
inst->remove(block);
progress = true;
}
}
if (progress)
invalidate_live_intervals();
return progress;
}
/**
* Eliminate FIND_LIVE_CHANNEL instructions occurring outside any control
* flow. We could probably do better here with some form of divergence
* analysis.
*/
bool
vec4_visitor::eliminate_find_live_channel()
{
bool progress = false;
unsigned depth = 0;
if (!brw_stage_has_packed_dispatch(devinfo, stage, stage_prog_data)) {
/* The optimization below assumes that channel zero is live on thread
* dispatch, which may not be the case if the fixed function dispatches
* threads sparsely.
*/
return false;
}
foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) {
switch (inst->opcode) {
case BRW_OPCODE_IF:
case BRW_OPCODE_DO:
depth++;
break;
case BRW_OPCODE_ENDIF:
case BRW_OPCODE_WHILE:
depth--;
break;
case SHADER_OPCODE_FIND_LIVE_CHANNEL:
if (depth == 0) {
inst->opcode = BRW_OPCODE_MOV;
inst->src[0] = brw_imm_d(0);
inst->force_writemask_all = true;
progress = true;
}
break;
default:
break;
}
}
return progress;
}
/**
* Splits virtual GRFs requesting more than one contiguous physical register.
*
* We initially create large virtual GRFs for temporary structures, arrays,
* and matrices, so that the visitor functions can add offsets to work their
* way down to the actual member being accessed. But when it comes to
* optimization, we'd like to treat each register as individual storage if
* possible.
*
* So far, the only thing that might prevent splitting is a send message from
* a GRF on IVB.
*/
void
vec4_visitor::split_virtual_grfs()
{
int num_vars = this->alloc.count;
int new_virtual_grf[num_vars];
bool split_grf[num_vars];
memset(new_virtual_grf, 0, sizeof(new_virtual_grf));
/* Try to split anything > 0 sized. */
for (int i = 0; i < num_vars; i++) {
split_grf[i] = this->alloc.sizes[i] != 1;
}
/* Check that the instructions are compatible with the registers we're trying
* to split.
*/
foreach_block_and_inst(block, vec4_instruction, inst, cfg) {
if (inst->dst.file == VGRF && regs_written(inst) > 1)
split_grf[inst->dst.nr] = false;
for (int i = 0; i < 3; i++) {
if (inst->src[i].file == VGRF && regs_read(inst, i) > 1)
split_grf[inst->src[i].nr] = false;
}
}
/* Allocate new space for split regs. Note that the virtual
* numbers will be contiguous.
*/
for (int i = 0; i < num_vars; i++) {
if (!split_grf[i])
continue;
new_virtual_grf[i] = alloc.allocate(1);
for (unsigned j = 2; j < this->alloc.sizes[i]; j++) {
unsigned reg = alloc.allocate(1);
assert(reg == new_virtual_grf[i] + j - 1);
(void) reg;
}
this->alloc.sizes[i] = 1;
}
foreach_block_and_inst(block, vec4_instruction, inst, cfg) {
if (inst->dst.file == VGRF && split_grf[inst->dst.nr] &&
inst->dst.offset / REG_SIZE != 0) {
inst->dst.nr = (new_virtual_grf[inst->dst.nr] +
inst->dst.offset / REG_SIZE - 1);
inst->dst.offset %= REG_SIZE;
}
for (int i = 0; i < 3; i++) {
if (inst->src[i].file == VGRF && split_grf[inst->src[i].nr] &&
inst->src[i].offset / REG_SIZE != 0) {
inst->src[i].nr = (new_virtual_grf[inst->src[i].nr] +
inst->src[i].offset / REG_SIZE - 1);
inst->src[i].offset %= REG_SIZE;
}
}
}
invalidate_live_intervals();
}
void
vec4_visitor::dump_instruction(backend_instruction *be_inst)
{
dump_instruction(be_inst, stderr);
}
void
vec4_visitor::dump_instruction(backend_instruction *be_inst, FILE *file)
{
vec4_instruction *inst = (vec4_instruction *)be_inst;
if (inst->predicate) {
fprintf(file, "(%cf0.%d%s) ",
inst->predicate_inverse ? '-' : '+',
inst->flag_subreg,
pred_ctrl_align16[inst->predicate]);
}
fprintf(file, "%s(%d)", brw_instruction_name(devinfo, inst->opcode),
inst->exec_size);
if (inst->saturate)
fprintf(file, ".sat");
if (inst->conditional_mod) {
fprintf(file, "%s", conditional_modifier[inst->conditional_mod]);
if (!inst->predicate &&
(devinfo->gen < 5 || (inst->opcode != BRW_OPCODE_SEL &&
inst->opcode != BRW_OPCODE_IF &&
inst->opcode != BRW_OPCODE_WHILE))) {
fprintf(file, ".f0.%d", inst->flag_subreg);
}
}
fprintf(file, " ");
switch (inst->dst.file) {
case VGRF:
fprintf(file, "vgrf%d", inst->dst.nr);
break;
case FIXED_GRF:
fprintf(file, "g%d", inst->dst.nr);
break;
case MRF:
fprintf(file, "m%d", inst->dst.nr);
break;
case ARF:
switch (inst->dst.nr) {
case BRW_ARF_NULL:
fprintf(file, "null");
break;
case BRW_ARF_ADDRESS:
fprintf(file, "a0.%d", inst->dst.subnr);
break;
case BRW_ARF_ACCUMULATOR:
fprintf(file, "acc%d", inst->dst.subnr);
break;
case BRW_ARF_FLAG:
fprintf(file, "f%d.%d", inst->dst.nr & 0xf, inst->dst.subnr);
break;
default:
fprintf(file, "arf%d.%d", inst->dst.nr & 0xf, inst->dst.subnr);
break;
}
break;
case BAD_FILE:
fprintf(file, "(null)");
break;
case IMM:
case ATTR:
case UNIFORM:
unreachable("not reached");
}
if (inst->dst.offset ||
(inst->dst.file == VGRF &&
alloc.sizes[inst->dst.nr] * REG_SIZE != inst->size_written)) {
const unsigned reg_size = (inst->dst.file == UNIFORM ? 16 : REG_SIZE);
fprintf(file, "+%d.%d", inst->dst.offset / reg_size,
inst->dst.offset % reg_size);
}
if (inst->dst.writemask != WRITEMASK_XYZW) {
fprintf(file, ".");
if (inst->dst.writemask & 1)
fprintf(file, "x");
if (inst->dst.writemask & 2)
fprintf(file, "y");
if (inst->dst.writemask & 4)
fprintf(file, "z");
if (inst->dst.writemask & 8)
fprintf(file, "w");
}
fprintf(file, ":%s", brw_reg_type_letters(inst->dst.type));
if (inst->src[0].file != BAD_FILE)
fprintf(file, ", ");
for (int i = 0; i < 3 && inst->src[i].file != BAD_FILE; i++) {
if (inst->src[i].negate)
fprintf(file, "-");
if (inst->src[i].abs)
fprintf(file, "|");
switch (inst->src[i].file) {
case VGRF:
fprintf(file, "vgrf%d", inst->src[i].nr);
break;
case FIXED_GRF:
fprintf(file, "g%d.%d", inst->src[i].nr, inst->src[i].subnr);
break;
case ATTR:
fprintf(file, "attr%d", inst->src[i].nr);
break;
case UNIFORM:
fprintf(file, "u%d", inst->src[i].nr);
break;
case IMM:
switch (inst->src[i].type) {
case BRW_REGISTER_TYPE_F:
fprintf(file, "%fF", inst->src[i].f);
break;
case BRW_REGISTER_TYPE_DF:
fprintf(file, "%fDF", inst->src[i].df);
break;
case BRW_REGISTER_TYPE_D:
fprintf(file, "%dD", inst->src[i].d);
break;
case BRW_REGISTER_TYPE_UD:
fprintf(file, "%uU", inst->src[i].ud);
break;
case BRW_REGISTER_TYPE_VF:
fprintf(file, "[%-gF, %-gF, %-gF, %-gF]",
brw_vf_to_float((inst->src[i].ud >> 0) & 0xff),
brw_vf_to_float((inst->src[i].ud >> 8) & 0xff),
brw_vf_to_float((inst->src[i].ud >> 16) & 0xff),
brw_vf_to_float((inst->src[i].ud >> 24) & 0xff));
break;
default:
fprintf(file, "???");
break;
}
break;
case ARF:
switch (inst->src[i].nr) {
case BRW_ARF_NULL:
fprintf(file, "null");
break;
case BRW_ARF_ADDRESS:
fprintf(file, "a0.%d", inst->src[i].subnr);
break;
case BRW_ARF_ACCUMULATOR:
fprintf(file, "acc%d", inst->src[i].subnr);
break;
case BRW_ARF_FLAG:
fprintf(file, "f%d.%d", inst->src[i].nr & 0xf, inst->src[i].subnr);
break;
default:
fprintf(file, "arf%d.%d", inst->src[i].nr & 0xf, inst->src[i].subnr);
break;
}
break;
case BAD_FILE:
fprintf(file, "(null)");
break;
case MRF:
unreachable("not reached");
}
if (inst->src[i].offset ||
(inst->src[i].file == VGRF &&
alloc.sizes[inst->src[i].nr] * REG_SIZE != inst->size_read(i))) {
const unsigned reg_size = (inst->src[i].file == UNIFORM ? 16 : REG_SIZE);
fprintf(file, "+%d.%d", inst->src[i].offset / reg_size,
inst->src[i].offset % reg_size);
}
if (inst->src[i].file != IMM) {
static const char *chans[4] = {"x", "y", "z", "w"};
fprintf(file, ".");
for (int c = 0; c < 4; c++) {
fprintf(file, "%s", chans[BRW_GET_SWZ(inst->src[i].swizzle, c)]);
}
}
if (inst->src[i].abs)
fprintf(file, "|");
if (inst->src[i].file != IMM) {
fprintf(file, ":%s", brw_reg_type_letters(inst->src[i].type));
}
if (i < 2 && inst->src[i + 1].file != BAD_FILE)
fprintf(file, ", ");
}
if (inst->force_writemask_all)
fprintf(file, " NoMask");
if (inst->exec_size != 8)
fprintf(file, " group%d", inst->group);
fprintf(file, "\n");
}
static inline struct brw_reg
attribute_to_hw_reg(int attr, brw_reg_type type, bool interleaved)
{
struct brw_reg reg;
unsigned width = REG_SIZE / 2 / MAX2(4, type_sz(type));
if (interleaved) {
reg = stride(brw_vecn_grf(width, attr / 2, (attr % 2) * 4), 0, width, 1);
} else {
reg = brw_vecn_grf(width, attr, 0);
}
reg.type = type;
return reg;
}
/**
* Replace each register of type ATTR in this->instructions with a reference
* to a fixed HW register.
*
* If interleaved is true, then each attribute takes up half a register, with
* register N containing attribute 2*N in its first half and attribute 2*N+1
* in its second half (this corresponds to the payload setup used by geometry
* shaders in "single" or "dual instanced" dispatch mode). If interleaved is
* false, then each attribute takes up a whole register, with register N
* containing attribute N (this corresponds to the payload setup used by
* vertex shaders, and by geometry shaders in "dual object" dispatch mode).
*/
void
vec4_visitor::lower_attributes_to_hw_regs(const int *attribute_map,
bool interleaved)
{
foreach_block_and_inst(block, vec4_instruction, inst, cfg) {
for (int i = 0; i < 3; i++) {
if (inst->src[i].file != ATTR)
continue;
int grf = attribute_map[inst->src[i].nr +
inst->src[i].offset / REG_SIZE];
assert(inst->src[i].offset % REG_SIZE == 0);
/* All attributes used in the shader need to have been assigned a
* hardware register by the caller
*/
assert(grf != 0);
struct brw_reg reg =
attribute_to_hw_reg(grf, inst->src[i].type, interleaved);
reg.swizzle = inst->src[i].swizzle;
if (inst->src[i].abs)
reg = brw_abs(reg);
if (inst->src[i].negate)
reg = negate(reg);
inst->src[i] = reg;
}
}
}
int
vec4_vs_visitor::setup_attributes(int payload_reg)
{
int nr_attributes;
int attribute_map[VERT_ATTRIB_MAX + 2];
memset(attribute_map, 0, sizeof(attribute_map));
nr_attributes = 0;
GLbitfield64 vs_inputs = vs_prog_data->inputs_read;
while (vs_inputs) {
GLuint first = ffsll(vs_inputs) - 1;
int needed_slots =
(vs_prog_data->double_inputs_read & BITFIELD64_BIT(first)) ? 2 : 1;
for (int c = 0; c < needed_slots; c++) {
attribute_map[first + c] = payload_reg + nr_attributes;
nr_attributes++;
vs_inputs &= ~BITFIELD64_BIT(first + c);
}
}
/* VertexID is stored by the VF as the last vertex element, but we
* don't represent it with a flag in inputs_read, so we call it
* VERT_ATTRIB_MAX.
*/
if (vs_prog_data->uses_vertexid || vs_prog_data->uses_instanceid ||
vs_prog_data->uses_basevertex || vs_prog_data->uses_baseinstance) {
attribute_map[VERT_ATTRIB_MAX] = payload_reg + nr_attributes;
nr_attributes++;
}
if (vs_prog_data->uses_drawid) {
attribute_map[VERT_ATTRIB_MAX + 1] = payload_reg + nr_attributes;
nr_attributes++;
}
lower_attributes_to_hw_regs(attribute_map, false /* interleaved */);
return payload_reg + vs_prog_data->nr_attribute_slots;
}
int
vec4_visitor::setup_uniforms(int reg)
{
prog_data->base.dispatch_grf_start_reg = reg;
/* The pre-gen6 VS requires that some push constants get loaded no
* matter what, or the GPU would hang.
*/
if (devinfo->gen < 6 && this->uniforms == 0) {
stage_prog_data->param =
reralloc(NULL, stage_prog_data->param, const gl_constant_value *, 4);
for (unsigned int i = 0; i < 4; i++) {
unsigned int slot = this->uniforms * 4 + i;
static gl_constant_value zero = { 0.0 };
stage_prog_data->param[slot] = &zero;
}
this->uniforms++;
reg++;
} else {
reg += ALIGN(uniforms, 2) / 2;
}
stage_prog_data->nr_params = this->uniforms * 4;
prog_data->base.curb_read_length =
reg - prog_data->base.dispatch_grf_start_reg;
return reg;
}
void
vec4_vs_visitor::setup_payload(void)
{
int reg = 0;
/* The payload always contains important data in g0, which contains
* the URB handles that are passed on to the URB write at the end
* of the thread. So, we always start push constants at g1.
*/
reg++;
reg = setup_uniforms(reg);
reg = setup_attributes(reg);
this->first_non_payload_grf = reg;
}
bool
vec4_visitor::lower_minmax()
{
assert(devinfo->gen < 6);
bool progress = false;
foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) {
const vec4_builder ibld(this, block, inst);
if (inst->opcode == BRW_OPCODE_SEL &&
inst->predicate == BRW_PREDICATE_NONE) {
/* FIXME: Using CMP doesn't preserve the NaN propagation semantics of
* the original SEL.L/GE instruction
*/
ibld.CMP(ibld.null_reg_d(), inst->src[0], inst->src[1],
inst->conditional_mod);
inst->predicate = BRW_PREDICATE_NORMAL;
inst->conditional_mod = BRW_CONDITIONAL_NONE;
progress = true;
}
}
if (progress)
invalidate_live_intervals();
return progress;
}
src_reg
vec4_visitor::get_timestamp()
{
assert(devinfo->gen >= 7);
src_reg ts = src_reg(brw_reg(BRW_ARCHITECTURE_REGISTER_FILE,
BRW_ARF_TIMESTAMP,
0,
0,
0,
BRW_REGISTER_TYPE_UD,
BRW_VERTICAL_STRIDE_0,
BRW_WIDTH_4,
BRW_HORIZONTAL_STRIDE_4,
BRW_SWIZZLE_XYZW,
WRITEMASK_XYZW));
dst_reg dst = dst_reg(this, glsl_type::uvec4_type);
vec4_instruction *mov = emit(MOV(dst, ts));
/* We want to read the 3 fields we care about (mostly field 0, but also 2)
* even if it's not enabled in the dispatch.
*/
mov->force_writemask_all = true;
return src_reg(dst);
}
void
vec4_visitor::emit_shader_time_begin()
{
current_annotation = "shader time start";
shader_start_time = get_timestamp();
}
void
vec4_visitor::emit_shader_time_end()
{
current_annotation = "shader time end";
src_reg shader_end_time = get_timestamp();
/* Check that there weren't any timestamp reset events (assuming these
* were the only two timestamp reads that happened).
*/
src_reg reset_end = shader_end_time;
reset_end.swizzle = BRW_SWIZZLE_ZZZZ;
vec4_instruction *test = emit(AND(dst_null_ud(), reset_end, brw_imm_ud(1u)));
test->conditional_mod = BRW_CONDITIONAL_Z;
emit(IF(BRW_PREDICATE_NORMAL));
/* Take the current timestamp and get the delta. */
shader_start_time.negate = true;
dst_reg diff = dst_reg(this, glsl_type::uint_type);
emit(ADD(diff, shader_start_time, shader_end_time));
/* If there were no instructions between the two timestamp gets, the diff
* is 2 cycles. Remove that overhead, so I can forget about that when
* trying to determine the time taken for single instructions.
*/
emit(ADD(diff, src_reg(diff), brw_imm_ud(-2u)));
emit_shader_time_write(0, src_reg(diff));
emit_shader_time_write(1, brw_imm_ud(1u));
emit(BRW_OPCODE_ELSE);
emit_shader_time_write(2, brw_imm_ud(1u));
emit(BRW_OPCODE_ENDIF);
}
void
vec4_visitor::emit_shader_time_write(int shader_time_subindex, src_reg value)
{
dst_reg dst =
dst_reg(this, glsl_type::get_array_instance(glsl_type::vec4_type, 2));
dst_reg offset = dst;
dst_reg time = dst;
time.offset += REG_SIZE;
offset.type = BRW_REGISTER_TYPE_UD;
int index = shader_time_index * 3 + shader_time_subindex;
emit(MOV(offset, brw_imm_d(index * SHADER_TIME_STRIDE)));
time.type = BRW_REGISTER_TYPE_UD;
emit(MOV(time, value));
vec4_instruction *inst =
emit(SHADER_OPCODE_SHADER_TIME_ADD, dst_reg(), src_reg(dst));
inst->mlen = 2;
}
void
vec4_visitor::convert_to_hw_regs()
{
foreach_block_and_inst(block, vec4_instruction, inst, cfg) {
for (int i = 0; i < 3; i++) {
struct src_reg &src = inst->src[i];
struct brw_reg reg;
switch (src.file) {
case VGRF: {
const unsigned type_size = type_sz(src.type);
const unsigned width = REG_SIZE / 2 / MAX2(4, type_size);
reg = byte_offset(brw_vecn_grf(width, src.nr, 0), src.offset);
reg.type = src.type;
reg.abs = src.abs;
reg.negate = src.negate;
break;
}
case UNIFORM: {
const unsigned width = REG_SIZE / 2 / MAX2(4, type_sz(src.type));
reg = stride(byte_offset(brw_vec4_grf(
prog_data->base.dispatch_grf_start_reg +
src.nr / 2, src.nr % 2 * 4),
src.offset),
0, width, 1);
reg.type = src.type;
reg.abs = src.abs;
reg.negate = src.negate;
/* This should have been moved to pull constants. */
assert(!src.reladdr);
break;
}
case FIXED_GRF:
if (type_sz(src.type) == 8) {
reg = src.as_brw_reg();
break;
}
/* fallthrough */
case ARF:
case IMM:
continue;
case BAD_FILE:
/* Probably unused. */
reg = brw_null_reg();
break;
case MRF:
case ATTR:
unreachable("not reached");
}
apply_logical_swizzle(®, inst, i);
src = reg;
}
if (inst->is_3src(devinfo)) {
/* 3-src instructions with scalar sources support arbitrary subnr,
* but don't actually use swizzles. Convert swizzle into subnr.
* Skip this for double-precision instructions: RepCtrl=1 is not
* allowed for them and needs special handling.
*/
for (int i = 0; i < 3; i++) {
if (inst->src[i].vstride == BRW_VERTICAL_STRIDE_0 &&
type_sz(inst->src[i].type) < 8) {
assert(brw_is_single_value_swizzle(inst->src[i].swizzle));
inst->src[i].subnr += 4 * BRW_GET_SWZ(inst->src[i].swizzle, 0);
}
}
}
dst_reg &dst = inst->dst;
struct brw_reg reg;
switch (inst->dst.file) {
case VGRF:
reg = byte_offset(brw_vec8_grf(dst.nr, 0), dst.offset);
reg.type = dst.type;
reg.writemask = dst.writemask;
break;
case MRF:
reg = byte_offset(brw_message_reg(dst.nr), dst.offset);
assert((reg.nr & ~BRW_MRF_COMPR4) < BRW_MAX_MRF(devinfo->gen));
reg.type = dst.type;
reg.writemask = dst.writemask;
break;
case ARF:
case FIXED_GRF:
reg = dst.as_brw_reg();
break;
case BAD_FILE:
reg = brw_null_reg();
break;
case IMM:
case ATTR:
case UNIFORM:
unreachable("not reached");
}
dst = reg;
}
}
static bool
stage_uses_interleaved_attributes(unsigned stage,
enum shader_dispatch_mode dispatch_mode)
{
switch (stage) {
case MESA_SHADER_TESS_EVAL:
return true;
case MESA_SHADER_GEOMETRY:
return dispatch_mode != DISPATCH_MODE_4X2_DUAL_OBJECT;
default:
return false;
}
}
/**
* Get the closest native SIMD width supported by the hardware for instruction
* \p inst. The instruction will be left untouched by
* vec4_visitor::lower_simd_width() if the returned value matches the
* instruction's original execution size.
*/
static unsigned
get_lowered_simd_width(const struct gen_device_info *devinfo,
enum shader_dispatch_mode dispatch_mode,
unsigned stage, const vec4_instruction *inst)
{
/* Do not split some instructions that require special handling */
switch (inst->opcode) {
case SHADER_OPCODE_GEN4_SCRATCH_READ:
case SHADER_OPCODE_GEN4_SCRATCH_WRITE:
return inst->exec_size;
default:
break;
}
unsigned lowered_width = MIN2(16, inst->exec_size);
/* We need to split some cases of double-precision instructions that write
* 2 registers. We only need to care about this in gen7 because that is the
* only hardware that implements fp64 in Align16.
*/
if (devinfo->gen == 7 && inst->size_written > REG_SIZE) {
/* Align16 8-wide double-precision SEL does not work well. Verified
* empirically.
*/
if (inst->opcode == BRW_OPCODE_SEL && type_sz(inst->dst.type) == 8)
lowered_width = MIN2(lowered_width, 4);
/* HSW PRM, 3D Media GPGPU Engine, Region Alignment Rules for Direct
* Register Addressing:
*
* "When destination spans two registers, the source MUST span two
* registers."
*/
for (unsigned i = 0; i < 3; i++) {
if (inst->src[i].file == BAD_FILE)
continue;
if (inst->size_read(i) <= REG_SIZE)
lowered_width = MIN2(lowered_width, 4);
/* Interleaved attribute setups use a vertical stride of 0, which
* makes them hit the associated instruction decompression bug in gen7.
* Split them to prevent this.
*/
if (inst->src[i].file == ATTR &&
stage_uses_interleaved_attributes(stage, dispatch_mode))
lowered_width = MIN2(lowered_width, 4);
}
}
return lowered_width;
}
static bool
dst_src_regions_overlap(vec4_instruction *inst)
{
if (inst->size_written == 0)
return false;
unsigned dst_start = inst->dst.offset;
unsigned dst_end = dst_start + inst->size_written - 1;
for (int i = 0; i < 3; i++) {
if (inst->src[i].file == BAD_FILE)
continue;
if (inst->dst.file != inst->src[i].file ||
inst->dst.nr != inst->src[i].nr)
continue;
unsigned src_start = inst->src[i].offset;
unsigned src_end = src_start + inst->size_read(i) - 1;
if ((dst_start >= src_start && dst_start <= src_end) ||
(dst_end >= src_start && dst_end <= src_end) ||
(dst_start <= src_start && dst_end >= src_end)) {
return true;
}
}
return false;
}
bool
vec4_visitor::lower_simd_width()
{
bool progress = false;
foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) {
const unsigned lowered_width =
get_lowered_simd_width(devinfo, prog_data->dispatch_mode, stage, inst);
assert(lowered_width <= inst->exec_size);
if (lowered_width == inst->exec_size)
continue;
/* We need to deal with source / destination overlaps when splitting.
* The hardware supports reading from and writing to the same register
* in the same instruction, but we need to be careful that each split
* instruction we produce does not corrupt the source of the next.
*
* The easiest way to handle this is to make the split instructions write
* to temporaries if there is an src/dst overlap and then move from the
* temporaries to the original destination. We also need to consider
* instructions that do partial writes via align1 opcodes, in which case
* we need to make sure that the we initialize the temporary with the
* value of the instruction's dst.
*/
bool needs_temp = dst_src_regions_overlap(inst);
for (unsigned n = 0; n < inst->exec_size / lowered_width; n++) {
unsigned channel_offset = lowered_width * n;
unsigned size_written = lowered_width * type_sz(inst->dst.type);
/* Create the split instruction from the original so that we copy all
* relevant instruction fields, then set the width and calculate the
* new dst/src regions.
*/
vec4_instruction *linst = new(mem_ctx) vec4_instruction(*inst);
linst->exec_size = lowered_width;
linst->group = channel_offset;
linst->size_written = size_written;
/* Compute split dst region */
dst_reg dst;
if (needs_temp) {
unsigned num_regs = DIV_ROUND_UP(size_written, REG_SIZE);
dst = retype(dst_reg(VGRF, alloc.allocate(num_regs)),
inst->dst.type);
if (inst->is_align1_partial_write()) {
vec4_instruction *copy = MOV(dst, src_reg(inst->dst));
copy->exec_size = lowered_width;
copy->group = channel_offset;
copy->size_written = size_written;
inst->insert_before(block, copy);
}
} else {
dst = horiz_offset(inst->dst, channel_offset);
}
linst->dst = dst;
/* Compute split source regions */
for (int i = 0; i < 3; i++) {
if (linst->src[i].file == BAD_FILE)
continue;
if (!is_uniform(linst->src[i]))
linst->src[i] = horiz_offset(linst->src[i], channel_offset);
}
inst->insert_before(block, linst);
/* If we used a temporary to store the result of the split
* instruction, copy the result to the original destination
*/
if (needs_temp) {
vec4_instruction *mov =
MOV(offset(inst->dst, lowered_width, n), src_reg(dst));
mov->exec_size = lowered_width;
mov->group = channel_offset;
mov->size_written = size_written;
mov->predicate = inst->predicate;
inst->insert_before(block, mov);
}
}
inst->remove(block);
progress = true;
}
if (progress)
invalidate_live_intervals();
return progress;
}
static bool
is_align1_df(vec4_instruction *inst)
{
switch (inst->opcode) {
case VEC4_OPCODE_FROM_DOUBLE:
case VEC4_OPCODE_TO_DOUBLE:
case VEC4_OPCODE_PICK_LOW_32BIT:
case VEC4_OPCODE_PICK_HIGH_32BIT:
case VEC4_OPCODE_SET_LOW_32BIT:
case VEC4_OPCODE_SET_HIGH_32BIT:
return true;
default:
return false;
}
}
static brw_predicate
scalarize_predicate(brw_predicate predicate, unsigned writemask)
{
if (predicate != BRW_PREDICATE_NORMAL)
return predicate;
switch (writemask) {
case WRITEMASK_X:
return BRW_PREDICATE_ALIGN16_REPLICATE_X;
case WRITEMASK_Y:
return BRW_PREDICATE_ALIGN16_REPLICATE_Y;
case WRITEMASK_Z:
return BRW_PREDICATE_ALIGN16_REPLICATE_Z;
case WRITEMASK_W:
return BRW_PREDICATE_ALIGN16_REPLICATE_W;
default:
unreachable("invalid writemask");
}
}
/* Gen7 has a hardware decompression bug that we can exploit to represent
* handful of additional swizzles natively.
*/
static bool
is_gen7_supported_64bit_swizzle(vec4_instruction *inst, unsigned arg)
{
switch (inst->src[arg].swizzle) {
case BRW_SWIZZLE_XXXX:
case BRW_SWIZZLE_YYYY:
case BRW_SWIZZLE_ZZZZ:
case BRW_SWIZZLE_WWWW:
case BRW_SWIZZLE_XYXY:
case BRW_SWIZZLE_YXYX:
case BRW_SWIZZLE_ZWZW:
case BRW_SWIZZLE_WZWZ:
return true;
default:
return false;
}
}
/* 64-bit sources use regions with a width of 2. These 2 elements in each row
* can be addressed using 32-bit swizzles (which is what the hardware supports)
* but it also means that the swizzle we apply on the first two components of a
* dvec4 is coupled with the swizzle we use for the last 2. In other words,
* only some specific swizzle combinations can be natively supported.
*
* FIXME: we can go an step further and implement even more swizzle
* variations using only partial scalarization.
*
* For more details see:
* https://bugs.freedesktop.org/show_bug.cgi?id=92760#c82
*/
bool
vec4_visitor::is_supported_64bit_region(vec4_instruction *inst, unsigned arg)
{
const src_reg &src = inst->src[arg];
assert(type_sz(src.type) == 8);
/* Uniform regions have a vstride=0. Because we use 2-wide rows with
* 64-bit regions it means that we cannot access components Z/W, so
* return false for any such case. Interleaved attributes will also be
* mapped to GRF registers with a vstride of 0, so apply the same
* treatment.
*/
if ((is_uniform(src) ||
(stage_uses_interleaved_attributes(stage, prog_data->dispatch_mode) &&
src.file == ATTR)) &&
(brw_mask_for_swizzle(src.swizzle) & 12))
return false;
switch (src.swizzle) {
case BRW_SWIZZLE_XYZW:
case BRW_SWIZZLE_XXZZ:
case BRW_SWIZZLE_YYWW:
case BRW_SWIZZLE_YXWZ:
return true;
default:
return devinfo->gen == 7 && is_gen7_supported_64bit_swizzle(inst, arg);
}
}
bool
vec4_visitor::scalarize_df()
{
bool progress = false;
foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) {
/* Skip DF instructions that operate in Align1 mode */
if (is_align1_df(inst))
continue;
/* Check if this is a double-precision instruction */
bool is_double = type_sz(inst->dst.type) == 8;
for (int arg = 0; !is_double && arg < 3; arg++) {
is_double = inst->src[arg].file != BAD_FILE &&
type_sz(inst->src[arg].type) == 8;
}
if (!is_double)
continue;
/* Skip the lowering for specific regioning scenarios that we can
* support natively.
*/
bool skip_lowering = true;
/* XY and ZW writemasks operate in 32-bit, which means that they don't
* have a native 64-bit representation and they should always be split.
*/
if (inst->dst.writemask == WRITEMASK_XY ||
inst->dst.writemask == WRITEMASK_ZW) {
skip_lowering = false;
} else {
for (unsigned i = 0; i < 3; i++) {
if (inst->src[i].file == BAD_FILE || type_sz(inst->src[i].type) < 8)
continue;
skip_lowering = skip_lowering && is_supported_64bit_region(inst, i);
}
}
if (skip_lowering)
continue;
/* Generate scalar instructions for each enabled channel */
for (unsigned chan = 0; chan < 4; chan++) {
unsigned chan_mask = 1 << chan;
if (!(inst->dst.writemask & chan_mask))
continue;
vec4_instruction *scalar_inst = new(mem_ctx) vec4_instruction(*inst);
for (unsigned i = 0; i < 3; i++) {
unsigned swz = BRW_GET_SWZ(inst->src[i].swizzle, chan);
scalar_inst->src[i].swizzle = BRW_SWIZZLE4(swz, swz, swz, swz);
}
scalar_inst->dst.writemask = chan_mask;
if (inst->predicate != BRW_PREDICATE_NONE) {
scalar_inst->predicate =
scalarize_predicate(inst->predicate, chan_mask);
}
inst->insert_before(block, scalar_inst);
}
inst->remove(block);
progress = true;
}
if (progress)
invalidate_live_intervals();
return progress;
}
bool
vec4_visitor::lower_64bit_mad_to_mul_add()
{
bool progress = false;
foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) {
if (inst->opcode != BRW_OPCODE_MAD)
continue;
if (type_sz(inst->dst.type) != 8)
continue;
dst_reg mul_dst = dst_reg(this, glsl_type::dvec4_type);
/* Use the copy constructor so we copy all relevant instruction fields
* from the original mad into the add and mul instructions
*/
vec4_instruction *mul = new(mem_ctx) vec4_instruction(*inst);
mul->opcode = BRW_OPCODE_MUL;
mul->dst = mul_dst;
mul->src[0] = inst->src[1];
mul->src[1] = inst->src[2];
mul->src[2].file = BAD_FILE;
vec4_instruction *add = new(mem_ctx) vec4_instruction(*inst);
add->opcode = BRW_OPCODE_ADD;
add->src[0] = src_reg(mul_dst);
add->src[1] = inst->src[0];
add->src[2].file = BAD_FILE;
inst->insert_before(block, mul);
inst->insert_before(block, add);
inst->remove(block);
progress = true;
}
if (progress)
invalidate_live_intervals();
return progress;
}
/* The align16 hardware can only do 32-bit swizzle channels, so we need to
* translate the logical 64-bit swizzle channels that we use in the Vec4 IR
* to 32-bit swizzle channels in hardware registers.
*
* @inst and @arg identify the original vec4 IR source operand we need to
* translate the swizzle for and @hw_reg is the hardware register where we
* will write the hardware swizzle to use.
*
* This pass assumes that Align16/DF instructions have been fully scalarized
* previously so there is just one 64-bit swizzle channel to deal with for any
* given Vec4 IR source.
*/
void
vec4_visitor::apply_logical_swizzle(struct brw_reg *hw_reg,
vec4_instruction *inst, int arg)
{
src_reg reg = inst->src[arg];
if (reg.file == BAD_FILE || reg.file == BRW_IMMEDIATE_VALUE)
return;
/* If this is not a 64-bit operand or this is a scalar instruction we don't
* need to do anything about the swizzles.
*/
if(type_sz(reg.type) < 8 || is_align1_df(inst)) {
hw_reg->swizzle = reg.swizzle;
return;
}
/* Take the 64-bit logical swizzle channel and translate it to 32-bit */
assert(brw_is_single_value_swizzle(reg.swizzle) ||
is_supported_64bit_region(inst, arg));
if (is_supported_64bit_region(inst, arg) &&
!is_gen7_supported_64bit_swizzle(inst, arg)) {
/* Supported 64-bit swizzles are those such that their first two
* components, when expanded to 32-bit swizzles, match the semantics
* of the original 64-bit swizzle with 2-wide row regioning.
*/
unsigned swizzle0 = BRW_GET_SWZ(reg.swizzle, 0);
unsigned swizzle1 = BRW_GET_SWZ(reg.swizzle, 1);
hw_reg->swizzle = BRW_SWIZZLE4(swizzle0 * 2, swizzle0 * 2 + 1,
swizzle1 * 2, swizzle1 * 2 + 1);
} else {
/* If we got here then we have one of the following:
*
* 1. An unsupported swizzle, which should be single-value thanks to the
* scalarization pass.
*
* 2. A gen7 supported swizzle. These can be single-value or double-value
* swizzles. If the latter, they are never cross-dvec2 channels. For
* these we always need to activate the gen7 vstride=0 exploit.
*/
unsigned swizzle0 = BRW_GET_SWZ(reg.swizzle, 0);
unsigned swizzle1 = BRW_GET_SWZ(reg.swizzle, 1);
assert((swizzle0 < 2) == (swizzle1 < 2));
/* To gain access to Z/W components we need to select the second half
* of the register and then use a X/Y swizzle to select Z/W respectively.
*/
if (swizzle0 >= 2) {
*hw_reg = suboffset(*hw_reg, 2);
swizzle0 -= 2;
swizzle1 -= 2;
}
/* All gen7-specific supported swizzles require the vstride=0 exploit */
if (devinfo->gen == 7 && is_gen7_supported_64bit_swizzle(inst, arg))
hw_reg->vstride = BRW_VERTICAL_STRIDE_0;
/* Any 64-bit source with an offset at 16B is intended to address the
* second half of a register and needs a vertical stride of 0 so we:
*
* 1. Don't violate register region restrictions.
* 2. Activate the gen7 instruction decompresion bug exploit when
* execsize > 4
*/
if (hw_reg->subnr % REG_SIZE == 16) {
assert(devinfo->gen == 7);
hw_reg->vstride = BRW_VERTICAL_STRIDE_0;
}
hw_reg->swizzle = BRW_SWIZZLE4(swizzle0 * 2, swizzle0 * 2 + 1,
swizzle1 * 2, swizzle1 * 2 + 1);
}
}
bool
vec4_visitor::run()
{
if (shader_time_index >= 0)
emit_shader_time_begin();
emit_prolog();
emit_nir_code();
if (failed)
return false;
base_ir = NULL;
emit_thread_end();
calculate_cfg();
/* Before any optimization, push array accesses out to scratch
* space where we need them to be. This pass may allocate new
* virtual GRFs, so we want to do it early. It also makes sure
* that we have reladdr computations available for CSE, since we'll
* often do repeated subexpressions for those.
*/
move_grf_array_access_to_scratch();
move_uniform_array_access_to_pull_constants();
pack_uniform_registers();
move_push_constants_to_pull_constants();
split_virtual_grfs();
#define OPT(pass, args...) ({ \
pass_num++; \
bool this_progress = pass(args); \
\
if (unlikely(INTEL_DEBUG & DEBUG_OPTIMIZER) && this_progress) { \
char filename[64]; \
snprintf(filename, 64, "%s-%s-%02d-%02d-" #pass, \
stage_abbrev, nir->info->name, iteration, pass_num); \
\
backend_shader::dump_instructions(filename); \
} \
\
progress = progress || this_progress; \
this_progress; \
})
if (unlikely(INTEL_DEBUG & DEBUG_OPTIMIZER)) {
char filename[64];
snprintf(filename, 64, "%s-%s-00-00-start",
stage_abbrev, nir->info->name);
backend_shader::dump_instructions(filename);
}
bool progress;
int iteration = 0;
int pass_num = 0;
do {
progress = false;
pass_num = 0;
iteration++;
OPT(opt_predicated_break, this);
OPT(opt_reduce_swizzle);
OPT(dead_code_eliminate);
OPT(dead_control_flow_eliminate, this);
OPT(opt_copy_propagation);
OPT(opt_cmod_propagation);
OPT(opt_cse);
OPT(opt_algebraic);
OPT(opt_register_coalesce);
OPT(eliminate_find_live_channel);
} while (progress);
pass_num = 0;
if (OPT(opt_vector_float)) {
OPT(opt_cse);
OPT(opt_copy_propagation, false);
OPT(opt_copy_propagation, true);
OPT(dead_code_eliminate);
}
if (devinfo->gen <= 5 && OPT(lower_minmax)) {
OPT(opt_cmod_propagation);
OPT(opt_cse);
OPT(opt_copy_propagation);
OPT(dead_code_eliminate);
}
if (OPT(lower_simd_width)) {
OPT(opt_copy_propagation);
OPT(dead_code_eliminate);
}
if (failed)
return false;
OPT(lower_64bit_mad_to_mul_add);
/* Run this before payload setup because tesselation shaders
* rely on it to prevent cross dvec2 regioning on DF attributes
* that are setup so that XY are on the second half of register and
* ZW are in the first half of the next.
*/
OPT(scalarize_df);
setup_payload();
if (unlikely(INTEL_DEBUG & DEBUG_SPILL_VEC4)) {
/* Debug of register spilling: Go spill everything. */
const int grf_count = alloc.count;
float spill_costs[alloc.count];
bool no_spill[alloc.count];
evaluate_spill_costs(spill_costs, no_spill);
for (int i = 0; i < grf_count; i++) {
if (no_spill[i])
continue;
spill_reg(i);
}
/* We want to run this after spilling because 64-bit (un)spills need to
* emit code to shuffle 64-bit data for the 32-bit scratch read/write
* messages that can produce unsupported 64-bit swizzle regions.
*/
OPT(scalarize_df);
}
bool allocated_without_spills = reg_allocate();
if (!allocated_without_spills) {
compiler->shader_perf_log(log_data,
"%s shader triggered register spilling. "
"Try reducing the number of live vec4 values "
"to improve performance.\n",
stage_name);
while (!reg_allocate()) {
if (failed)
return false;
}
/* We want to run this after spilling because 64-bit (un)spills need to
* emit code to shuffle 64-bit data for the 32-bit scratch read/write
* messages that can produce unsupported 64-bit swizzle regions.
*/
OPT(scalarize_df);
}
opt_schedule_instructions();
opt_set_dependency_control();
convert_to_hw_regs();
if (last_scratch > 0) {
prog_data->base.total_scratch =
brw_get_scratch_size(last_scratch * REG_SIZE);
}
return !failed;
}
} /* namespace brw */
extern "C" {
/**
* Compile a vertex shader.
*
* Returns the final assembly and the program's size.
*/
const unsigned *
brw_compile_vs(const struct brw_compiler *compiler, void *log_data,
void *mem_ctx,
const struct brw_vs_prog_key *key,
struct brw_vs_prog_data *prog_data,
const nir_shader *src_shader,
gl_clip_plane *clip_planes,
bool use_legacy_snorm_formula,
int shader_time_index,
unsigned *final_assembly_size,
char **error_str)
{
const bool is_scalar = compiler->scalar_stage[MESA_SHADER_VERTEX];
nir_shader *shader = nir_shader_clone(mem_ctx, src_shader);
shader = brw_nir_apply_sampler_key(shader, compiler, &key->tex, is_scalar);
brw_nir_lower_vs_inputs(shader, is_scalar,
use_legacy_snorm_formula, key->gl_attrib_wa_flags);
brw_nir_lower_vue_outputs(shader, is_scalar);
shader = brw_postprocess_nir(shader, compiler, is_scalar);
const unsigned *assembly = NULL;
prog_data->base.clip_distance_mask =
((1 << shader->info->clip_distance_array_size) - 1);
prog_data->base.cull_distance_mask =
((1 << shader->info->cull_distance_array_size) - 1) <<
shader->info->clip_distance_array_size;
unsigned nr_attribute_slots = _mesa_bitcount_64(prog_data->inputs_read);
/* gl_VertexID and gl_InstanceID are system values, but arrive via an
* incoming vertex attribute. So, add an extra slot.
*/
if (shader->info->system_values_read &
(BITFIELD64_BIT(SYSTEM_VALUE_BASE_VERTEX) |
BITFIELD64_BIT(SYSTEM_VALUE_BASE_INSTANCE) |
BITFIELD64_BIT(SYSTEM_VALUE_VERTEX_ID_ZERO_BASE) |
BITFIELD64_BIT(SYSTEM_VALUE_INSTANCE_ID))) {
nr_attribute_slots++;
}
/* gl_DrawID has its very own vec4 */
if (shader->info->system_values_read &
BITFIELD64_BIT(SYSTEM_VALUE_DRAW_ID)) {
nr_attribute_slots++;
}
unsigned nr_attributes = nr_attribute_slots -
DIV_ROUND_UP(_mesa_bitcount_64(shader->info->double_inputs_read), 2);
/* The 3DSTATE_VS documentation lists the lower bound on "Vertex URB Entry
* Read Length" as 1 in vec4 mode, and 0 in SIMD8 mode. Empirically, in
* vec4 mode, the hardware appears to wedge unless we read something.
*/
if (is_scalar)
prog_data->base.urb_read_length =
DIV_ROUND_UP(nr_attribute_slots, 2);
else
prog_data->base.urb_read_length =
DIV_ROUND_UP(MAX2(nr_attribute_slots, 1), 2);
prog_data->nr_attributes = nr_attributes;
prog_data->nr_attribute_slots = nr_attribute_slots;
/* Since vertex shaders reuse the same VUE entry for inputs and outputs
* (overwriting the original contents), we need to make sure the size is
* the larger of the two.
*/
const unsigned vue_entries =
MAX2(nr_attribute_slots, (unsigned)prog_data->base.vue_map.num_slots);
if (compiler->devinfo->gen == 6)
prog_data->base.urb_entry_size = DIV_ROUND_UP(vue_entries, 8);
else
prog_data->base.urb_entry_size = DIV_ROUND_UP(vue_entries, 4);
if (INTEL_DEBUG & DEBUG_VS) {
fprintf(stderr, "VS Output ");
brw_print_vue_map(stderr, &prog_data->base.vue_map);
}
if (is_scalar) {
prog_data->base.dispatch_mode = DISPATCH_MODE_SIMD8;
fs_visitor v(compiler, log_data, mem_ctx, key, &prog_data->base.base,
NULL, /* prog; Only used for TEXTURE_RECTANGLE on gen < 8 */
shader, 8, shader_time_index);
if (!v.run_vs(clip_planes)) {
if (error_str)
*error_str = ralloc_strdup(mem_ctx, v.fail_msg);
return NULL;
}
prog_data->base.base.dispatch_grf_start_reg = v.payload.num_regs;
fs_generator g(compiler, log_data, mem_ctx, (void *) key,
&prog_data->base.base, v.promoted_constants,
v.runtime_check_aads_emit, MESA_SHADER_VERTEX);
if (INTEL_DEBUG & DEBUG_VS) {
const char *debug_name =
ralloc_asprintf(mem_ctx, "%s vertex shader %s",
shader->info->label ? shader->info->label :
"unnamed",
shader->info->name);
g.enable_debug(debug_name);
}
g.generate_code(v.cfg, 8);
assembly = g.get_assembly(final_assembly_size);
}
if (!assembly) {
prog_data->base.dispatch_mode = DISPATCH_MODE_4X2_DUAL_OBJECT;
vec4_vs_visitor v(compiler, log_data, key, prog_data,
shader, clip_planes, mem_ctx,
shader_time_index, use_legacy_snorm_formula);
if (!v.run()) {
if (error_str)
*error_str = ralloc_strdup(mem_ctx, v.fail_msg);
return NULL;
}
assembly = brw_vec4_generate_assembly(compiler, log_data, mem_ctx,
shader, &prog_data->base, v.cfg,
final_assembly_size);
}
return assembly;
}
} /* extern "C" */