// This file implements the MemorySSA class.
//
//===----------------------------------------------------------------===//
+#include "llvm/Transforms/Utils/MemorySSA.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Transforms/Scalar.h"
-#include "llvm/Transforms/Utils/MemorySSA.h"
#include <algorithm>
#define DEBUG_TYPE "memoryssa"
MemorySSA::MemorySSA(Function &Func, AliasAnalysis *AA, DominatorTree *DT)
: AA(AA), DT(DT), F(Func), LiveOnEntryDef(nullptr), Walker(nullptr),
NextID(0) {
- getWalker(); // Ensure MemorySSA has been built.
+ buildMemorySSA();
}
MemorySSA::MemorySSA(MemorySSA &&MSSA)
return Res.first->second.get();
}
-MemorySSAWalker *MemorySSA::getWalker() {
- if (Walker)
- return Walker.get();
-
- Walker = make_unique<CachingWalker>(this, AA, DT);
-
+void MemorySSA::buildMemorySSA() {
// We create an access to represent "live on entry", for things like
// arguments or users of globals, where the memory they use is defined before
// the beginning of the function. We do not actually insert it into the IR.
SmallPtrSet<BasicBlock *, 16> Visited;
renamePass(DT->getRootNode(), LiveOnEntryDef.get(), Visited);
+ MemorySSAWalker *Walker = getWalker();
+
// Now optimize the MemoryUse's defining access to point to the nearest
// dominating clobbering def.
// This ensures that MemoryUse's that are killed by the same store are
for (auto &BB : F)
if (!Visited.count(&BB))
markUnreachableAsLiveOnEntry(&BB);
+}
+MemorySSAWalker *MemorySSA::getWalker() {
+ if (Walker)
+ return Walker.get();
+
+ Walker = make_unique<CachingWalker>(this, AA, DT);
return Walker.get();
}