void optimize(IRUnit& unit, IRBuilder& irBuilder, TransKind kind) {
Timer timer(Timer::optimize);
assertx(checkEverything(unit));
auto const hasLoop = RuntimeOption::EvalJitLoops && cfgHasLoop(unit);
auto const func = unit.entry()->front().marker().func();
auto const regionMode = pgoRegionMode(*func);
auto const traceMode = kind != TransKind::Optimize ||
regionMode == PGORegionMode::Hottrace;
// TODO (#5792564): Guard relaxation doesn't work with loops.
// TODO (#6599498): Guard relaxation is broken in wholecfg mode.
if (shouldHHIRRelaxGuards() && !hasLoop && traceMode) {
Timer _t(Timer::optimize_relaxGuards);
const bool simple = kind == TransKind::Profile &&
(RuntimeOption::EvalJitRegionSelector == "tracelet" ||
RuntimeOption::EvalJitRegionSelector == "method");
RelaxGuardsFlags flags = (RelaxGuardsFlags)
(RelaxReflow | (simple ? RelaxSimple : RelaxNormal));
auto changed = relaxGuards(unit, *irBuilder.guards(), flags);
if (changed) {
printUnit(6, unit, "after guard relaxation");
mandatoryDCE(unit); // relaxGuards can leave unreachable preds.
}
if (RuntimeOption::EvalHHIRSimplification) {
doPass(unit, simplifyPass, DCE::Minimal);
doPass(unit, cleanCfg, DCE::None);
}
}
fullDCE(unit);
printUnit(6, unit, " after initial DCE ");
assertx(checkEverything(unit));
if (RuntimeOption::EvalHHIRTypeCheckHoisting) {
doPass(unit, hoistTypeChecks, DCE::None);
}
if (RuntimeOption::EvalHHIRPredictionOpts) {
doPass(unit, optimizePredictions, DCE::None);
}
if (RuntimeOption::EvalHHIRSimplification) {
doPass(unit, simplifyPass, DCE::Full);
doPass(unit, cleanCfg, DCE::None);
}
if (RuntimeOption::EvalHHIRGlobalValueNumbering) {
doPass(unit, gvn, DCE::Full);
}
if (kind != TransKind::Profile && RuntimeOption::EvalHHIRMemoryOpts) {
doPass(unit, optimizeLoads, DCE::Full);
}
if (kind != TransKind::Profile && RuntimeOption::EvalHHIRMemoryOpts) {
doPass(unit, optimizeStores, DCE::Full);
}
if (kind != TransKind::Profile && RuntimeOption::EvalHHIRRefcountOpts) {
doPass(unit, optimizeRefcounts2, DCE::Full);
}
if (RuntimeOption::EvalHHIRLICM) {
if (kind != TransKind::Profile && hasLoop) {
// The clean pass is just to stress lack of pre_headers for now, since
// LICM is a disabled prototype pass.
doPass(unit, cleanCfg, DCE::None);
doPass(unit, optimizeLoopInvariantCode, DCE::Minimal);
}
}
doPass(unit, removeExitPlaceholders, DCE::Full);
if (RuntimeOption::EvalHHIRGenerateAsserts) {
doPass(unit, insertAsserts, DCE::None);
}
}
void optimize(IRUnit& unit, IRBuilder& irBuilder, TransKind kind) {
Timer _t(Timer::optimize);
auto const finishPass = [&] (const char* msg) {
if (msg) {
printUnit(6, unit, folly::format("after {}", msg).str().c_str());
}
assertx(checkCfg(unit));
assertx(checkTmpsSpanningCalls(unit));
if (debug) {
forEachInst(rpoSortCfg(unit), [&](IRInstruction* inst) {
assertx(checkOperandTypes(inst, &unit));
});
}
};
auto const doPass = [&] (void (*fn)(IRUnit&), const char* msg = nullptr) {
fn(unit);
finishPass(msg);
};
auto const dce = [&] (const char* which) {
if (!RuntimeOption::EvalHHIRDeadCodeElim) return;
eliminateDeadCode(unit);
finishPass(folly::format("{} DCE", which).str().c_str());
};
auto const simplifyPass = [] (IRUnit& unit) {
boost::dynamic_bitset<> reachable(unit.numBlocks());
reachable.set(unit.entry()->id());
auto const blocks = rpoSortCfg(unit);
for (auto block : blocks) {
// Skip unreachable blocks, or simplify() cries.
if (!reachable.test(block->id())) continue;
for (auto& inst : *block) simplify(unit, &inst);
if (auto const b = block->back().next()) reachable.set(b->id());
if (auto const b = block->back().taken()) reachable.set(b->id());
}
};
auto const doSimplify = RuntimeOption::EvalHHIRExtraOptPass &&
RuntimeOption::EvalHHIRSimplification;
auto const hasLoop = RuntimeOption::EvalJitLoops && cfgHasLoop(unit);
auto const traceMode = kind != TransKind::Optimize ||
RuntimeOption::EvalJitPGORegionSelector == "hottrace";
// TODO (#5792564): Guard relaxation doesn't work with loops.
// TODO (#6599498): Guard relaxation is broken in wholecfg mode.
if (shouldHHIRRelaxGuards() && !hasLoop && traceMode) {
Timer _t(Timer::optimize_relaxGuards);
const bool simple = kind == TransKind::Profile &&
(RuntimeOption::EvalJitRegionSelector == "tracelet" ||
RuntimeOption::EvalJitRegionSelector == "method");
RelaxGuardsFlags flags = (RelaxGuardsFlags)
(RelaxReflow | (simple ? RelaxSimple : RelaxNormal));
auto changed = relaxGuards(unit, *irBuilder.guards(), flags);
if (changed) finishPass("guard relaxation");
if (doSimplify) {
doPass(simplifyPass, "guard relaxation simplify");
}
}
// This is vestigial (it removes some instructions needed by the old refcount
// opts pass), and will be removed soon.
eliminateTakes(unit);
dce("initial");
if (RuntimeOption::EvalHHIRPredictionOpts) {
doPass(optimizePredictions, "prediction opts");
}
if (doSimplify) {
doPass(simplifyPass, "simplify");
dce("simplify");
}
if (RuntimeOption::EvalHHIRGlobalValueNumbering) {
doPass(gvn);
dce("gvn");
}
if (kind != TransKind::Profile && RuntimeOption::EvalHHIRMemoryOpts) {
doPass(optimizeLoads);
dce("loadelim");
}
/*
* Note: doing this pass this late might not be ideal, in particular because
* we've already turned some StLoc instructions into StLocNT.
*
* But right now there are assumptions preventing us from doing it before
* refcount opts. (Refcount opts needs to see all the StLocs explicitly
* because it makes assumptions about whether references are consumed based
* on that.)
*/
if (kind != TransKind::Profile && RuntimeOption::EvalHHIRMemoryOpts) {
doPass(optimizeStores);
dce("storeelim");
}
if (kind != TransKind::Profile && RuntimeOption::EvalHHIRRefcountOpts) {
doPass(optimizeRefcounts2);
dce("refcount");
}
if (RuntimeOption::EvalHHIRGenerateAsserts) {
doPass(insertAsserts);
}
}
void optimize(IRUnit& unit, IRBuilder& irBuilder, TransKind kind) {
Timer _t(Timer::optimize);
auto finishPass = [&](const char* msg) {
if (msg) {
printUnit(6, unit, folly::format("after {}", msg).str().c_str());
}
assert(checkCfg(unit));
assert(checkTmpsSpanningCalls(unit));
if (debug) {
forEachInst(rpoSortCfg(unit), [&](IRInstruction* inst) {
assert(checkOperandTypes(inst, &unit));
});
}
};
auto doPass = [&](void (*fn)(IRUnit&), const char* msg = nullptr) {
fn(unit);
finishPass(msg);
};
auto dce = [&](const char* which) {
if (!RuntimeOption::EvalHHIRDeadCodeElim) return;
eliminateDeadCode(unit);
finishPass(folly::format("{} DCE", which).str().c_str());
};
auto const doReoptimize = RuntimeOption::EvalHHIRExtraOptPass &&
(RuntimeOption::EvalHHIRCse || RuntimeOption::EvalHHIRSimplification);
auto const hasLoop = RuntimeOption::EvalJitLoops && cfgHasLoop(unit);
// TODO(#5792564): Guard relaxation doesn't work with loops.
if (shouldHHIRRelaxGuards() && !hasLoop) {
Timer _t(Timer::optimize_relaxGuards);
const bool simple = kind == TransKind::Profile &&
(RuntimeOption::EvalJitRegionSelector == "tracelet" ||
RuntimeOption::EvalJitRegionSelector == "method");
RelaxGuardsFlags flags = (RelaxGuardsFlags)
(RelaxReflow | (simple ? RelaxSimple : RelaxNormal));
auto changed = relaxGuards(unit, *irBuilder.guards(), flags);
if (changed) finishPass("guard relaxation");
if (doReoptimize) {
irBuilder.reoptimize();
finishPass("guard relaxation reoptimize");
}
}
if (RuntimeOption::EvalHHIRRefcountOpts) {
optimizeRefcounts(unit, FrameStateMgr{unit.entry()->front().marker()});
finishPass("refcount opts");
}
dce("initial");
if (RuntimeOption::EvalHHIRPredictionOpts) {
doPass(optimizePredictions, "prediction opts");
}
if (doReoptimize) {
irBuilder.reoptimize();
finishPass("reoptimize");
dce("reoptimize");
}
if (RuntimeOption::EvalHHIRGlobalValueNumbering) {
doPass(gvn);
dce("gvn");
}
if (kind != TransKind::Profile && RuntimeOption::EvalHHIRMemoryOpts) {
doPass(optimizeLoads);
dce("loadelim");
}
/*
* Note: doing this pass this late might not be ideal, in particular because
* we've already turned some StLoc instructions into StLocNT.
*
* But right now there are assumptions preventing us from doing it before
* refcount opts. (Refcount opts needs to see all the StLocs explicitly
* because it makes assumptions about whether references are consumed based
* on that.)
*/
if (kind != TransKind::Profile && RuntimeOption::EvalHHIRMemoryOpts) {
doPass(optimizeStores);
dce("storeelim");
}
if (RuntimeOption::EvalHHIRGenerateAsserts) {
doPass(insertAsserts, "RefCnt asserts");
}
}