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-rw-r--r--src/amd/compiler/aco_lower_phis.cpp168
1 files changed, 79 insertions, 89 deletions
diff --git a/src/amd/compiler/aco_lower_phis.cpp b/src/amd/compiler/aco_lower_phis.cpp
index c47f59e7cc6..b90d99ee424 100644
--- a/src/amd/compiler/aco_lower_phis.cpp
+++ b/src/amd/compiler/aco_lower_phis.cpp
@@ -34,91 +34,56 @@
namespace aco {
-struct phi_use {
- Block *block;
- unsigned phi_def;
-
- bool operator<(const phi_use& other) const {
- return std::make_tuple(block, phi_def) <
- std::make_tuple(other.block, other.phi_def);
- }
-};
-
struct ssa_state {
- std::map<unsigned, unsigned> latest;
- std::map<unsigned, std::map<phi_use, uint64_t>> phis;
+ bool needs_init;
+ uint64_t cur_undef_operands;
+
+ unsigned phi_block_idx;
+ unsigned loop_nest_depth;
+ std::map<unsigned, unsigned> writes;
+ std::vector<unsigned> latest;
};
-Operand get_ssa(Program *program, unsigned block_idx, ssa_state *state)
+Operand get_ssa(Program *program, unsigned block_idx, ssa_state *state, bool before_write)
{
- while (true) {
- auto pos = state->latest.find(block_idx);
- if (pos != state->latest.end())
- return Operand(Temp(pos->second, program->lane_mask));
-
- Block& block = program->blocks[block_idx];
- size_t pred = block.linear_preds.size();
- if (pred == 0) {
- return Operand(program->lane_mask);
- } else if (pred == 1) {
- block_idx = block.linear_preds[0];
- continue;
- } else {
- unsigned res = program->allocateId();
- state->latest[block_idx] = res;
-
- aco_ptr<Pseudo_instruction> phi{create_instruction<Pseudo_instruction>(aco_opcode::p_linear_phi, Format::PSEUDO, pred, 1)};
- for (unsigned i = 0; i < pred; i++) {
- phi->operands[i] = get_ssa(program, block.linear_preds[i], state);
- if (phi->operands[i].isTemp()) {
- assert(i < 64);
- state->phis[phi->operands[i].tempId()][(phi_use){&block, res}] |= (uint64_t)1 << i;
- }
- }
- phi->definitions[0] = Definition(Temp{res, program->lane_mask});
- block.instructions.emplace(block.instructions.begin(), std::move(phi));
-
- return Operand(Temp(res, program->lane_mask));
- }
+ if (!before_write) {
+ auto it = state->writes.find(block_idx);
+ if (it != state->writes.end())
+ return Operand(Temp(it->second, program->lane_mask));
+ if (state->latest[block_idx])
+ return Operand(Temp(state->latest[block_idx], program->lane_mask));
}
-}
-void update_phi(Program *program, ssa_state *state, Block *block, unsigned phi_def, uint64_t operand_mask) {
- for (auto& phi : block->instructions) {
- if (phi->opcode != aco_opcode::p_phi && phi->opcode != aco_opcode::p_linear_phi)
- break;
- if (phi->opcode != aco_opcode::p_linear_phi)
- continue;
- if (phi->definitions[0].tempId() != phi_def)
- continue;
- assert(ffsll(operand_mask) <= phi->operands.size());
-
- uint64_t operands = operand_mask;
- while (operands) {
- unsigned operand = u_bit_scan64(&operands);
- Operand new_operand = get_ssa(program, block->linear_preds[operand], state);
- phi->operands[operand] = new_operand;
- if (!new_operand.isUndefined())
- state->phis[new_operand.tempId()][(phi_use){block, phi_def}] |= (uint64_t)1 << operand;
- }
- return;
- }
- assert(false);
-}
+ Block& block = program->blocks[block_idx];
+ size_t pred = block.linear_preds.size();
+ if (pred == 0 || block.loop_nest_depth < state->loop_nest_depth) {
+ return Operand(program->lane_mask);
+ } else if (block.loop_nest_depth > state->loop_nest_depth) {
+ Operand op = get_ssa(program, block_idx - 1, state, false);
+ assert(!state->latest[block_idx]);
+ state->latest[block_idx] = op.tempId();
+ return op;
+ } else if (pred == 1 || block.kind & block_kind_loop_exit) {
+ Operand op = get_ssa(program, block.linear_preds[0], state, false);
+ assert(!state->latest[block_idx]);
+ state->latest[block_idx] = op.tempId();
+ return op;
+ } else if (block.kind & block_kind_loop_header &&
+ !(program->blocks[state->phi_block_idx].kind & block_kind_loop_exit)) {
+ return Operand(program->lane_mask);
+ } else {
+ unsigned res = program->allocateId();
+ assert(!state->latest[block_idx]);
+ state->latest[block_idx] = res;
-Temp write_ssa(Program *program, Block *block, ssa_state *state, unsigned previous) {
- unsigned id = program->allocateId();
- state->latest[block->index] = id;
+ aco_ptr<Pseudo_instruction> phi{create_instruction<Pseudo_instruction>(aco_opcode::p_linear_phi, Format::PSEUDO, pred, 1)};
+ for (unsigned i = 0; i < pred; i++)
+ phi->operands[i] = get_ssa(program, block.linear_preds[i], state, false);
+ phi->definitions[0] = Definition(Temp{res, program->lane_mask});
+ block.instructions.emplace(block.instructions.begin(), std::move(phi));
- /* update phis */
- if (previous) {
- std::map<phi_use, uint64_t> phis;
- phis.swap(state->phis[previous]);
- for (auto& phi : phis)
- update_phi(program, state, phi.first.block, phi.first.phi_def, phi.second);
+ return Operand(Temp(res, program->lane_mask));
}
-
- return {id, program->lane_mask};
}
void insert_before_logical_end(Block *block, aco_ptr<Instruction> instr)
@@ -136,29 +101,51 @@ void insert_before_logical_end(Block *block, aco_ptr<Instruction> instr)
block->instructions.insert(std::prev(it.base()), std::move(instr));
}
-void lower_divergent_bool_phi(Program *program, Block *block, aco_ptr<Instruction>& phi)
+void lower_divergent_bool_phi(Program *program, ssa_state *state, Block *block, aco_ptr<Instruction>& phi)
{
Builder bld(program);
- ssa_state state;
- state.latest[block->index] = phi->definitions[0].tempId();
+ state->latest.resize(program->blocks.size());
+
+ uint64_t undef_operands = 0;
+ for (unsigned i = 0; i < phi->operands.size(); i++)
+ undef_operands |= phi->operands[i].isUndefined() << i;
+
+ if (state->needs_init || undef_operands != state->cur_undef_operands ||
+ block->logical_preds.size() > 64) {
+ /* this only has to be done once per block unless the set of predecessors
+ * which are undefined changes */
+ state->cur_undef_operands = undef_operands;
+ state->phi_block_idx = block->index;
+ state->loop_nest_depth = block->loop_nest_depth;
+ if (block->kind & block_kind_loop_exit) {
+ state->loop_nest_depth += 1;
+ }
+ state->writes.clear();
+ state->needs_init = false;
+ }
+ std::fill(state->latest.begin(), state->latest.end(), 0);
+
+ for (unsigned i = 0; i < phi->operands.size(); i++) {
+ if (phi->operands[i].isUndefined())
+ continue;
+
+ state->writes[block->logical_preds[i]] = program->allocateId();
+ }
+
for (unsigned i = 0; i < phi->operands.size(); i++) {
Block *pred = &program->blocks[block->logical_preds[i]];
if (phi->operands[i].isUndefined())
continue;
- assert(phi->operands[i].isTemp());
- Temp phi_src = phi->operands[i].getTemp();
- assert(phi_src.regClass() == bld.lm);
-
- Operand cur = get_ssa(program, pred->index, &state);
+ Operand cur = get_ssa(program, pred->index, state, true);
assert(cur.regClass() == bld.lm);
- Temp new_cur = write_ssa(program, pred, &state, cur.isTemp() ? cur.tempId() : 0);
+ Temp new_cur = {state->writes.at(pred->index), program->lane_mask};
assert(new_cur.regClass() == bld.lm);
if (cur.isUndefined()) {
- insert_before_logical_end(pred, bld.sop1(aco_opcode::s_mov_b64, Definition(new_cur), phi_src).get_ptr());
+ insert_before_logical_end(pred, bld.sop1(aco_opcode::s_mov_b64, Definition(new_cur), phi->operands[i]).get_ptr());
} else {
Temp tmp1 = bld.tmp(bld.lm), tmp2 = bld.tmp(bld.lm);
insert_before_logical_end(pred,
@@ -166,7 +153,7 @@ void lower_divergent_bool_phi(Program *program, Block *block, aco_ptr<Instructio
cur, Operand(exec, bld.lm)).get_ptr());
insert_before_logical_end(pred,
bld.sop2(Builder::s_and, Definition(tmp2), bld.def(s1, scc),
- phi_src, Operand(exec, bld.lm)).get_ptr());
+ phi->operands[i].getTemp(), Operand(exec, bld.lm)).get_ptr());
insert_before_logical_end(pred,
bld.sop2(Builder::s_or, Definition(new_cur), bld.def(s1, scc),
tmp1, tmp2).get_ptr());
@@ -184,7 +171,7 @@ void lower_divergent_bool_phi(Program *program, Block *block, aco_ptr<Instructio
assert(phi->operands.size() == num_preds);
for (unsigned i = 0; i < num_preds; i++)
- phi->operands[i] = get_ssa(program, block->linear_preds[i], &state);
+ phi->operands[i] = get_ssa(program, block->linear_preds[i], state, false);
return;
}
@@ -215,12 +202,15 @@ void lower_subdword_phis(Program *program, Block *block, aco_ptr<Instruction>& p
void lower_phis(Program* program)
{
+ ssa_state state;
+
for (Block& block : program->blocks) {
+ state.needs_init = true;
for (aco_ptr<Instruction>& phi : block.instructions) {
if (phi->opcode == aco_opcode::p_phi) {
assert(program->wave_size == 64 ? phi->definitions[0].regClass() != s1 : phi->definitions[0].regClass() != s2);
if (phi->definitions[0].regClass() == program->lane_mask)
- lower_divergent_bool_phi(program, &block, phi);
+ lower_divergent_bool_phi(program, &state, &block, phi);
else if (phi->definitions[0].regClass().is_subdword())
lower_subdword_phis(program, &block, phi);
} else if (!is_phi(phi)) {
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 22:38:28 +0000