[RDF] Refine propagation of reached uses in liveness computation
llvm-svn: 300337
diff --git a/llvm/lib/Target/Hexagon/RDFLiveness.cpp b/llvm/lib/Target/Hexagon/RDFLiveness.cpp
index 25a4c5f..548235f 100644
--- a/llvm/lib/Target/Hexagon/RDFLiveness.cpp
+++ b/llvm/lib/Target/Hexagon/RDFLiveness.cpp
@@ -425,6 +425,7 @@
// phi use -> (map: reaching phi -> set of registers defined in between)
std::map<NodeId,std::map<NodeId,RegisterAggr>> PhiUp;
std::vector<NodeId> PhiUQ; // Work list of phis for upward propagation.
+ std::map<NodeId,RegisterAggr> PhiDRs; // Phi -> registers defined by it.
// Go over all phis.
for (NodeAddr<PhiNode*> PhiA : Phis) {
@@ -437,12 +438,15 @@
// For each def, add to the queue all reached (non-phi) defs.
SetVector<NodeId> DefQ;
NodeSet PhiDefs;
+ RegisterAggr DRs(PRI);
for (NodeAddr<RefNode*> R : PhiRefs) {
if (!DFG.IsRef<NodeAttrs::Def>(R))
continue;
+ DRs.insert(R.Addr->getRegRef(DFG));
DefQ.insert(R.Id);
PhiDefs.insert(R.Id);
}
+ PhiDRs.insert(std::make_pair(PhiA.Id, DRs));
// Collect the super-set of all possible reached uses. This set will
// contain all uses reached from this phi, either directly from the
@@ -615,14 +619,19 @@
// then add (R-MidDefs,U) to RealUseMap[P]
//
for (const std::pair<RegisterId,NodeRefSet> &T : RUM) {
- RegisterRef R = DFG.restrictRef(RegisterRef(T.first), UR);
- if (!R)
+ RegisterRef R(T.first);
+ // The current phi (PA) could be a phi for a regmask. It could
+ // reach a whole variety of uses that are not related to the
+ // specific upward phi (P.first).
+ const RegisterAggr &DRs = PhiDRs.at(P.first);
+ if (!DRs.hasAliasOf(R))
continue;
+ R = DRs.intersectWith(R);
for (std::pair<NodeId,LaneBitmask> V : T.second) {
- RegisterRef S = DFG.restrictRef(RegisterRef(R.Reg, V.second), R);
- if (!S)
+ LaneBitmask M = R.Mask & V.second;
+ if (M.none())
continue;
- if (RegisterRef SS = MidDefs.clearIn(S)) {
+ if (RegisterRef SS = MidDefs.clearIn(RegisterRef(R.Reg, M))) {
NodeRefSet &RS = RealUseMap[P.first][SS.Reg];
Changed |= RS.insert({V.first,SS.Mask}).second;
}