[JumpThreading] PR36133 enable/disable DominatorTree for LVI analysis
Summary:
The LazyValueInfo pass caches a copy of the DominatorTree when available.
Whenever there are pending DominatorTree updates within JumpThreading's
DeferredDominance object we cannot use the cached DT for LVI analysis.
This commit adds the new methods enableDT() and disableDT() to LVI.
JumpThreading also sets the appropriate usage model before calling LVI
analysis methods.
Fixes https://bugs.llvm.org/show_bug.cgi?id=36133
Reviewers: sebpop, dberlin, kuhar
Reviewed by: sebpop, kuhar
Subscribers: uabelho, llvm-commits, aprantl, hiraditya, a.elovikov
Differential Revision: https://reviews.llvm.org/D42717
llvm-svn: 325356
diff --git a/llvm/lib/Analysis/LazyValueInfo.cpp b/llvm/lib/Analysis/LazyValueInfo.cpp
index 1982a3b..65fd007 100644
--- a/llvm/lib/Analysis/LazyValueInfo.cpp
+++ b/llvm/lib/Analysis/LazyValueInfo.cpp
@@ -401,6 +401,7 @@
AssumptionCache *AC; ///< A pointer to the cache of @llvm.assume calls.
const DataLayout &DL; ///< A mandatory DataLayout
DominatorTree *DT; ///< An optional DT pointer.
+ DominatorTree *DisabledDT; ///< Stores DT if it's disabled.
ValueLatticeElement getBlockValue(Value *Val, BasicBlock *BB);
bool getEdgeValue(Value *V, BasicBlock *F, BasicBlock *T,
@@ -463,13 +464,30 @@
TheCache.eraseBlock(BB);
}
+ /// Disables use of the DominatorTree within LVI.
+ void disableDT() {
+ if (DT) {
+ assert(!DisabledDT && "Both DT and DisabledDT are not nullptr!");
+ std::swap(DT, DisabledDT);
+ }
+ }
+
+ /// Enables use of the DominatorTree within LVI. Does nothing if the class
+ /// instance was initialized without a DT pointer.
+ void enableDT() {
+ if (DisabledDT) {
+ assert(!DT && "Both DT and DisabledDT are not nullptr!");
+ std::swap(DT, DisabledDT);
+ }
+ }
+
/// This is the update interface to inform the cache that an edge from
/// PredBB to OldSucc has been threaded to be from PredBB to NewSucc.
void threadEdge(BasicBlock *PredBB,BasicBlock *OldSucc,BasicBlock *NewSucc);
LazyValueInfoImpl(AssumptionCache *AC, const DataLayout &DL,
DominatorTree *DT = nullptr)
- : AC(AC), DL(DL), DT(DT) {}
+ : AC(AC), DL(DL), DT(DT), DisabledDT(nullptr) {}
};
} // end anonymous namespace
@@ -1791,6 +1809,16 @@
}
}
+void LazyValueInfo::disableDT() {
+ if (PImpl)
+ getImpl(PImpl, AC, DL, DT).disableDT();
+}
+
+void LazyValueInfo::enableDT() {
+ if (PImpl)
+ getImpl(PImpl, AC, DL, DT).enableDT();
+}
+
// Print the LVI for the function arguments at the start of each basic block.
void LazyValueInfoAnnotatedWriter::emitBasicBlockStartAnnot(
const BasicBlock *BB, formatted_raw_ostream &OS) {