fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2025-12-22 07:00:12 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions 1
mesa/src/amd/compiler/aco_opt_value_numbering.cpp
Daniel Schürmann fb5a7902f2 aco: improve hashing for value numbering 
An improved hashing greatly reduces the number of collisions,
and thus, increases the speed for lookups in the hash table.
The hash function now uses Murmur3 written by Austin Appleby.

This patch also pre-reserves space for the hashmap to avoid rehashing.

Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4130>
2020-04-09 15:08:57 +00:00

460 lines
17 KiB
C++
Raw Blame History

/*
* Copyright © 2018 Valve 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 <map>
#include <unordered_map>
#include "aco_ir.h"
/*
* Implements the algorithm for dominator-tree value numbering
* from "Value Numbering" by Briggs, Cooper, and Simpson.
*/
namespace aco {
namespace {
inline
uint32_t murmur_32_scramble(uint32_t h, uint32_t k) {
k *= 0xcc9e2d51;
k = (k << 15) | (k >> 17);
h ^= k * 0x1b873593;
h = (h << 13) | (h >> 19);
h = h * 5 + 0xe6546b64;
return h;
}
template<typename T>
uint32_t hash_murmur_32(Instruction* instr)
{
uint32_t hash = uint32_t(instr->format) << 16 | uint32_t(instr->opcode);
for (const Operand& op : instr->operands)
hash = murmur_32_scramble(hash, op.constantValue());
/* skip format, opcode and pass_flags */
for (unsigned i = 2; i < (sizeof(T) >> 2); i++) {
uint32_t u;
/* Accesses it though a byte array, so doesn't violate the strict aliasing rule */
memcpy(&u, reinterpret_cast<uint8_t *>(instr) + i * 4, 4);
hash = murmur_32_scramble(hash, u);
}
/* Finalize. */
uint32_t len = instr->operands.size() + instr->definitions.size() + sizeof(T);
hash ^= len;
hash ^= hash >> 16;
hash *= 0x85ebca6b;
hash ^= hash >> 13;
hash *= 0xc2b2ae35;
hash ^= hash >> 16;
return hash;
}
struct InstrHash {
/* This hash function uses the Murmur3 algorithm written by Austin Appleby
* https://github.com/aappleby/smhasher/blob/master/src/MurmurHash3.cpp
*
* In order to calculate the expression set, only the right-hand-side of an
* instruction is used for the hash, i.e. everything except the definitions.
*/
std::size_t operator()(Instruction* instr) const
{
if (instr->isVOP3())
return hash_murmur_32<VOP3A_instruction>(instr);
if (instr->isDPP())
return hash_murmur_32<DPP_instruction>(instr);
switch (instr->format) {
case Format::SMEM:
return hash_murmur_32<SMEM_instruction>(instr);
case Format::VINTRP:
return hash_murmur_32<Interp_instruction>(instr);
case Format::DS:
return hash_murmur_32<DS_instruction>(instr);
case Format::SOPP:
return hash_murmur_32<SOPP_instruction>(instr);
case Format::SOPK:
return hash_murmur_32<SOPK_instruction>(instr);
case Format::EXP:
return hash_murmur_32<Export_instruction>(instr);
case Format::MUBUF:
return hash_murmur_32<MUBUF_instruction>(instr);
case Format::MIMG:
return hash_murmur_32<MIMG_instruction>(instr);
case Format::MTBUF:
return hash_murmur_32<MTBUF_instruction>(instr);
case Format::FLAT:
return hash_murmur_32<FLAT_instruction>(instr);
case Format::PSEUDO_BRANCH:
return hash_murmur_32<Pseudo_branch_instruction>(instr);
case Format::PSEUDO_REDUCTION:
return hash_murmur_32<Pseudo_reduction_instruction>(instr);
default:
return hash_murmur_32<Instruction>(instr);
}
}
};
struct InstrPred {
bool operator()(Instruction* a, Instruction* b) const
{
if (a->format != b->format)
return false;
if (a->opcode != b->opcode)
return false;
if (a->operands.size() != b->operands.size() || a->definitions.size() != b->definitions.size())
return false; /* possible with pseudo-instructions */
for (unsigned i = 0; i < a->operands.size(); i++) {
if (a->operands[i].isConstant()) {
if (!b->operands[i].isConstant())
return false;
if (a->operands[i].constantValue() != b->operands[i].constantValue())
return false;
}
else if (a->operands[i].isTemp()) {
if (!b->operands[i].isTemp())
return false;
if (a->operands[i].tempId() != b->operands[i].tempId())
return false;
}
else if (a->operands[i].isUndefined() ^ b->operands[i].isUndefined())
return false;
if (a->operands[i].isFixed()) {
if (!b->operands[i].isFixed())
return false;
if (a->operands[i].physReg() != b->operands[i].physReg())
return false;
if (a->operands[i].physReg() == exec && a->pass_flags != b->pass_flags)
return false;
}
}
for (unsigned i = 0; i < a->definitions.size(); i++) {
if (a->definitions[i].isTemp()) {
if (!b->definitions[i].isTemp())
return false;
if (a->definitions[i].regClass() != b->definitions[i].regClass())
return false;
}
if (a->definitions[i].isFixed()) {
if (!b->definitions[i].isFixed())
return false;
if (a->definitions[i].physReg() != b->definitions[i].physReg())
return false;
if (a->definitions[i].physReg() == exec)
return false;
}
}
if (a->opcode == aco_opcode::v_readfirstlane_b32)
return a->pass_flags == b->pass_flags;
/* The results of VOPC depend on the exec mask if used for subgroup operations. */
if ((uint32_t) a->format & (uint32_t) Format::VOPC && a->pass_flags != b->pass_flags)
return false;
if (a->isVOP3()) {
VOP3A_instruction* a3 = static_cast<VOP3A_instruction*>(a);
VOP3A_instruction* b3 = static_cast<VOP3A_instruction*>(b);
for (unsigned i = 0; i < 3; i++) {
if (a3->abs[i] != b3->abs[i] ||
a3->neg[i] != b3->neg[i])
return false;
}
return a3->clamp == b3->clamp &&
a3->omod == b3->omod &&
a3->opsel == b3->opsel;
}
if (a->isDPP()) {
DPP_instruction* aDPP = static_cast<DPP_instruction*>(a);
DPP_instruction* bDPP = static_cast<DPP_instruction*>(b);
return aDPP->pass_flags == bDPP->pass_flags &&
aDPP->dpp_ctrl == bDPP->dpp_ctrl &&
aDPP->bank_mask == bDPP->bank_mask &&
aDPP->row_mask == bDPP->row_mask &&
aDPP->bound_ctrl == bDPP->bound_ctrl &&
aDPP->abs[0] == bDPP->abs[0] &&
aDPP->abs[1] == bDPP->abs[1] &&
aDPP->neg[0] == bDPP->neg[0] &&
aDPP->neg[1] == bDPP->neg[1];
}
switch (a->format) {
case Format::SOPK: {
SOPK_instruction* aK = static_cast<SOPK_instruction*>(a);
SOPK_instruction* bK = static_cast<SOPK_instruction*>(b);
return aK->imm == bK->imm;
}
case Format::SMEM: {
SMEM_instruction* aS = static_cast<SMEM_instruction*>(a);
SMEM_instruction* bS = static_cast<SMEM_instruction*>(b);
return aS->can_reorder && bS->can_reorder &&
aS->glc == bS->glc && aS->nv == bS->nv;
}
case Format::VINTRP: {
Interp_instruction* aI = static_cast<Interp_instruction*>(a);
Interp_instruction* bI = static_cast<Interp_instruction*>(b);
if (aI->attribute != bI->attribute)
return false;
if (aI->component != bI->component)
return false;
return true;
}
case Format::PSEUDO_REDUCTION: {
Pseudo_reduction_instruction *aR = static_cast<Pseudo_reduction_instruction*>(a);
Pseudo_reduction_instruction *bR = static_cast<Pseudo_reduction_instruction*>(b);
return aR->pass_flags == bR->pass_flags &&
aR->reduce_op == bR->reduce_op &&
aR->cluster_size == bR->cluster_size;
}
case Format::MTBUF: {
MTBUF_instruction* aM = static_cast<MTBUF_instruction *>(a);
MTBUF_instruction* bM = static_cast<MTBUF_instruction *>(b);
return aM->can_reorder && bM->can_reorder &&
aM->barrier == bM->barrier &&
aM->dfmt == bM->dfmt &&
aM->nfmt == bM->nfmt &&
aM->offset == bM->offset &&
aM->offen == bM->offen &&
aM->idxen == bM->idxen &&
aM->glc == bM->glc &&
aM->dlc == bM->dlc &&
aM->slc == bM->slc &&
aM->tfe == bM->tfe &&
aM->disable_wqm == bM->disable_wqm;
}
case Format::MUBUF: {
MUBUF_instruction* aM = static_cast<MUBUF_instruction *>(a);
MUBUF_instruction* bM = static_cast<MUBUF_instruction *>(b);
return aM->can_reorder && bM->can_reorder &&
aM->barrier == bM->barrier &&
aM->offset == bM->offset &&
aM->offen == bM->offen &&
aM->idxen == bM->idxen &&
aM->glc == bM->glc &&
aM->dlc == bM->dlc &&
aM->slc == bM->slc &&
aM->tfe == bM->tfe &&
aM->lds == bM->lds &&
aM->disable_wqm == bM->disable_wqm;
}
/* we want to optimize these in NIR and don't hassle with load-store dependencies */
case Format::FLAT:
case Format::GLOBAL:
case Format::SCRATCH:
case Format::EXP:
case Format::SOPP:
case Format::PSEUDO_BRANCH:
case Format::PSEUDO_BARRIER:
return false;
case Format::DS: {
if (a->opcode != aco_opcode::ds_bpermute_b32 &&
a->opcode != aco_opcode::ds_permute_b32 &&
a->opcode != aco_opcode::ds_swizzle_b32)
return false;
DS_instruction* aD = static_cast<DS_instruction *>(a);
DS_instruction* bD = static_cast<DS_instruction *>(b);
return aD->pass_flags == bD->pass_flags &&
aD->gds == bD->gds &&
aD->offset0 == bD->offset0 &&
aD->offset1 == bD->offset1;
}
case Format::MIMG: {
MIMG_instruction* aM = static_cast<MIMG_instruction*>(a);
MIMG_instruction* bM = static_cast<MIMG_instruction*>(b);
return aM->can_reorder && bM->can_reorder &&
aM->barrier == bM->barrier &&
aM->dmask == bM->dmask &&
aM->unrm == bM->unrm &&
aM->glc == bM->glc &&
aM->slc == bM->slc &&
aM->tfe == bM->tfe &&
aM->da == bM->da &&
aM->lwe == bM->lwe &&
aM->r128 == bM->r128 &&
aM->a16 == bM->a16 &&
aM->d16 == bM->d16 &&
aM->disable_wqm == bM->disable_wqm;
}
default:
return true;
}
}
};
using expr_set = std::unordered_map<Instruction*, uint32_t, InstrHash, InstrPred>;
struct vn_ctx {
Program* program;
expr_set expr_values;
std::map<uint32_t, Temp> renames;
/* The exec id should be the same on the same level of control flow depth.
* Together with the check for dominator relations, it is safe to assume
* that the same exec_id also means the same execution mask.
* Discards increment the exec_id, so that it won't return to the previous value.
*/
uint32_t exec_id = 1;
vn_ctx(Program* program) : program(program) {
static_assert(sizeof(Temp) == 4, "Temp must fit in 32bits");
unsigned size = 0;
for (Block& block : program->blocks)
size += block.instructions.size();
expr_values.reserve(size);
}
};
/* dominates() returns true if the parent block dominates the child block and
* if the parent block is part of the same loop or has a smaller loop nest depth.
*/
bool dominates(vn_ctx& ctx, uint32_t parent, uint32_t child)
{
unsigned parent_loop_nest_depth = ctx.program->blocks[parent].loop_nest_depth;
while (parent < child && parent_loop_nest_depth <= ctx.program->blocks[child].loop_nest_depth)
child = ctx.program->blocks[child].logical_idom;
return parent == child;
}
void process_block(vn_ctx& ctx, Block& block)
{
std::vector<aco_ptr<Instruction>> new_instructions;
new_instructions.reserve(block.instructions.size());
for (aco_ptr<Instruction>& instr : block.instructions) {
/* first, rename operands */
for (Operand& op : instr->operands) {
if (!op.isTemp())
continue;
auto it = ctx.renames.find(op.tempId());
if (it != ctx.renames.end())
op.setTemp(it->second);
}
if (instr->opcode == aco_opcode::p_discard_if ||
instr->opcode == aco_opcode::p_demote_to_helper)
ctx.exec_id++;
if (instr->definitions.empty() || instr->opcode == aco_opcode::p_phi || instr->opcode == aco_opcode::p_linear_phi) {
new_instructions.emplace_back(std::move(instr));
continue;
}
/* simple copy-propagation through renaming */
if ((instr->opcode == aco_opcode::s_mov_b32 || instr->opcode == aco_opcode::s_mov_b64 || instr->opcode == aco_opcode::v_mov_b32) &&
!instr->definitions[0].isFixed() && instr->operands[0].isTemp() && instr->operands[0].regClass() == instr->definitions[0].regClass() &&
!instr->isDPP() && !((int)instr->format & (int)Format::SDWA)) {
ctx.renames[instr->definitions[0].tempId()] = instr->operands[0].getTemp();
}
instr->pass_flags = ctx.exec_id;
std::pair<expr_set::iterator, bool> res = ctx.expr_values.emplace(instr.get(), block.index);
/* if there was already an expression with the same value number */
if (!res.second) {
Instruction* orig_instr = res.first->first;
assert(instr->definitions.size() == orig_instr->definitions.size());
/* check if the original instruction dominates the current one */
if (dominates(ctx, res.first->second, block.index) &&
ctx.program->blocks[res.first->second].fp_mode.canReplace(block.fp_mode)) {
for (unsigned i = 0; i < instr->definitions.size(); i++) {
assert(instr->definitions[i].regClass() == orig_instr->definitions[i].regClass());
assert(instr->definitions[i].isTemp());
ctx.renames[instr->definitions[i].tempId()] = orig_instr->definitions[i].getTemp();
}
} else {
ctx.expr_values.erase(res.first);
ctx.expr_values.emplace(instr.get(), block.index);
new_instructions.emplace_back(std::move(instr));
}
} else {
new_instructions.emplace_back(std::move(instr));
}
}
block.instructions = std::move(new_instructions);
}
void rename_phi_operands(Block& block, std::map<uint32_t, Temp>& renames)
{
for (aco_ptr<Instruction>& phi : block.instructions) {
if (phi->opcode != aco_opcode::p_phi && phi->opcode != aco_opcode::p_linear_phi)
break;
for (Operand& op : phi->operands) {
if (!op.isTemp())
continue;
auto it = renames.find(op.tempId());
if (it != renames.end())
op.setTemp(it->second);
}
}
}
} /* end namespace */
void value_numbering(Program* program)
{
vn_ctx ctx(program);
std::vector<unsigned> loop_headers;
for (Block& block : program->blocks) {
assert(ctx.exec_id > 0);
/* decrement exec_id when leaving nested control flow */
if (block.kind & block_kind_loop_header)
loop_headers.push_back(block.index);
if (block.kind & block_kind_merge) {
ctx.exec_id--;
} else if (block.kind & block_kind_loop_exit) {
ctx.exec_id -= program->blocks[loop_headers.back()].linear_preds.size();
ctx.exec_id -= block.linear_preds.size();
loop_headers.pop_back();
}
if (block.logical_idom != -1)
process_block(ctx, block);
else
rename_phi_operands(block, ctx.renames);
/* increment exec_id when entering nested control flow */
if (block.kind & block_kind_branch ||
block.kind & block_kind_loop_preheader ||
block.kind & block_kind_break ||
block.kind & block_kind_continue ||
block.kind & block_kind_discard)
ctx.exec_id++;
else if (block.kind & block_kind_continue_or_break)
ctx.exec_id += 2;
}
/* rename loop header phi operands */
for (Block& block : program->blocks) {
if (block.kind & block_kind_loop_header)
rename_phi_operands(block, ctx.renames);
}
}
}
Reference in a new issue View git blame Copy permalink