aco: only create parallelcopy to restore exec at loop exit if needed

The operand isn't fixed to exec, which can mess up the spiller. This also
adds a new situation where a phi is needed.

Fixes dEQP-VK.ssbo.layout.random.descriptor_indexing.2 and an assertion
when compiling a Detroit: Become Human shader.

Fixes: 93c8ebfa ('aco: Initial commit of independent AMD compiler')
Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3257>
This commit is contained in:
Rhys Perry 2020-01-06 15:17:21 +00:00 committed by Marge Bot
parent 4537b97410
commit dba71de5c6

View file

@ -487,6 +487,7 @@ unsigned add_coupling_code(exec_ctx& ctx, Block* block,
assert(!(block->kind & block_kind_top_level) || info.num_exec_masks <= 2); assert(!(block->kind & block_kind_top_level) || info.num_exec_masks <= 2);
/* create the loop exit phis if not trivial */ /* create the loop exit phis if not trivial */
bool need_parallelcopy = false;
for (unsigned k = 0; k < info.num_exec_masks; k++) { for (unsigned k = 0; k < info.num_exec_masks; k++) {
Temp same = ctx.info[preds[0]].exec[k].first; Temp same = ctx.info[preds[0]].exec[k].first;
uint8_t type = ctx.info[header_preds[0]].exec[k].second; uint8_t type = ctx.info[header_preds[0]].exec[k].second;
@ -497,12 +498,31 @@ unsigned add_coupling_code(exec_ctx& ctx, Block* block,
trivial = false; trivial = false;
} }
if (k == info.num_exec_masks - 1u) {
bool all_liveout_exec = true;
bool all_not_liveout_exec = true;
for (unsigned pred : preds) {
all_liveout_exec = all_liveout_exec && same == ctx.program->blocks[pred].live_out_exec;
all_not_liveout_exec = all_not_liveout_exec && same != ctx.program->blocks[pred].live_out_exec;
}
if (!all_liveout_exec && !all_not_liveout_exec)
trivial = false;
else if (all_not_liveout_exec)
need_parallelcopy = true;
need_parallelcopy |= !trivial;
}
if (trivial) { if (trivial) {
ctx.info[idx].exec.emplace_back(same, type); ctx.info[idx].exec.emplace_back(same, type);
} else { } else {
/* create phi for loop footer */ /* create phi for loop footer */
aco_ptr<Pseudo_instruction> phi{create_instruction<Pseudo_instruction>(aco_opcode::p_linear_phi, Format::PSEUDO, preds.size(), 1)}; aco_ptr<Pseudo_instruction> phi{create_instruction<Pseudo_instruction>(aco_opcode::p_linear_phi, Format::PSEUDO, preds.size(), 1)};
phi->definitions[0] = bld.def(bld.lm); phi->definitions[0] = bld.def(bld.lm);
if (k == info.num_exec_masks - 1) {
phi->definitions[0].setFixed(exec);
need_parallelcopy = false;
}
for (unsigned i = 0; i < phi->operands.size(); i++) for (unsigned i = 0; i < phi->operands.size(); i++)
phi->operands[i] = Operand(ctx.info[preds[i]].exec[k].first); phi->operands[i] = Operand(ctx.info[preds[i]].exec[k].first);
ctx.info[idx].exec.emplace_back(bld.insert(std::move(phi)), type); ctx.info[idx].exec.emplace_back(bld.insert(std::move(phi)), type);
@ -533,8 +553,15 @@ unsigned add_coupling_code(exec_ctx& ctx, Block* block,
} }
assert(ctx.info[idx].exec.back().first.size() == bld.lm.size()); assert(ctx.info[idx].exec.back().first.size() == bld.lm.size());
ctx.info[idx].exec.back().first = bld.pseudo(aco_opcode::p_parallelcopy, bld.def(bld.lm, exec), if (need_parallelcopy) {
ctx.info[idx].exec.back().first); /* only create this parallelcopy is needed, since the operand isn't
* fixed to exec which causes the spiller to miscalculate register demand */
/* TODO: Fix register_demand calculation for spilling on loop exits.
* The problem is only mitigated because the register demand could be
* higher if the exec phi doesn't get assigned to exec. */
ctx.info[idx].exec.back().first = bld.pseudo(aco_opcode::p_parallelcopy, bld.def(bld.lm, exec),
ctx.info[idx].exec.back().first);
}
ctx.loop.pop_back(); ctx.loop.pop_back();
return i; return i;