/*
* Build the CFG, then the dominator tree, then use it to validate SSA.
* 1. Each src must be defined by some other instruction, and each dst must
* be defined by the current instruction.
* 2. Each src must be defined earlier in the same block or in a dominator.
* 3. Each dst must not be previously defined.
* 4. Treat tmps defined by DefConst as always defined.
* 5. Each predecessor of a reachable block must be reachable (deleted
* blocks must not have out-edges to reachable blocks).
* 6. The entry block must not have any predecessors.
*/
bool checkCfg(const IRUnit& unit) {
auto const blocksIds = rpoSortCfgWithIds(unit);
auto const& blocks = blocksIds.blocks;
jit::hash_set<const Edge*> edges;
// Entry block can't have predecessors.
assert(unit.entry()->numPreds() == 0);
// Check valid successor/predecessor edges.
for (Block* b : blocks) {
auto checkEdge = [&] (const Edge* e) {
assert(e->from() == b);
edges.insert(e);
for (auto& p : e->to()->preds()) if (&p == e) return;
assert(false); // did not find edge.
};
checkBlock(b);
if (auto *e = b->nextEdge()) checkEdge(e);
if (auto *e = b->takenEdge()) checkEdge(e);
}
for (Block* b : blocks) {
for (DEBUG_ONLY auto const &e : b->preds()) {
assert(&e == e.inst()->takenEdge() || &e == e.inst()->nextEdge());
assert(e.to() == b);
}
}
// visit dom tree in preorder, checking all tmps
auto const children = findDomChildren(unit, blocksIds);
StateVector<SSATmp, bool> defined0(unit, false);
forPreorderDoms(blocks.front(), children, defined0,
[] (Block* block, StateVector<SSATmp, bool>& defined) {
for (IRInstruction& inst : *block) {
for (DEBUG_ONLY SSATmp* src : inst.srcs()) {
assert(src->inst() != &inst);
assert_log(src->inst()->op() == DefConst ||
defined[src],
[&]{ return folly::format(
"src '{}' in '{}' came from '{}', which is not a "
"DefConst and is not defined at this use site",
src->toString(), inst.toString(),
src->inst()->toString()).str();
});
}
for (SSATmp& dst : inst.dsts()) {
assert(dst.inst() == &inst && inst.op() != DefConst);
assert(!defined[dst]);
defined[dst] = true;
}
}
});
return true;
}
/*
* Build the CFG, then the dominator tree, then use it to validate SSA.
* 1. Each src must be defined by some other instruction, and each dst must
* be defined by the current instruction.
* 2. Each src must be defined earlier in the same block or in a dominator.
* 3. Each dst must not be previously defined.
* 4. Treat tmps defined by DefConst as always defined.
* 5. Each predecessor of a reachable block must be reachable (deleted
* blocks must not have out-edges to reachable blocks).
*/
bool checkCfg(IRTrace* trace, const IRFactory& factory) {
forEachTraceBlock(trace, checkBlock);
// Check valid successor/predecessor edges.
auto const blocks = rpoSortCfg(trace, factory);
std::unordered_set<const Edge*> edges;
for (Block* b : blocks) {
auto checkEdge = [&] (const Edge* e) {
assert(e->from() == b);
edges.insert(e);
for (auto& p : e->to()->preds()) if (&p == e) return;
assert(false); // did not find edge.
};
if (auto *e = nextEdge(b)) checkEdge(e);
if (auto *e = takenEdge(b)) checkEdge(e);
}
for (Block* b : blocks) {
for (DEBUG_ONLY auto const &e : b->preds()) {
assert(&e == takenEdge(e.from()) || &e == nextEdge(e.from()));
assert(e.to() == b);
}
}
checkCatchTraces(trace, factory);
// visit dom tree in preorder, checking all tmps
auto const children = findDomChildren(blocks);
StateVector<SSATmp, bool> defined0(&factory, false);
forPreorderDoms(blocks.front(), children, defined0,
[] (Block* block, StateVector<SSATmp, bool>& defined) {
for (IRInstruction& inst : *block) {
for (DEBUG_ONLY SSATmp* src : inst.srcs()) {
assert(src->inst() != &inst);
assert_log(src->inst()->op() == DefConst ||
defined[src],
[&]{ return folly::format(
"src '{}' in '{}' came from '{}', which is not a "
"DefConst and is not defined at this use site",
src->toString(), inst.toString(),
src->inst()->toString()).str();
});
}
for (SSATmp& dst : inst.dsts()) {
assert(dst.inst() == &inst && inst.op() != DefConst);
assert(!defined[dst]);
defined[dst] = true;
}
}
});
return true;
}