1 files changed, 28 insertions, 0 deletions
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
index 28f6599..c3990d1 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
@@ -782,6 +782,24 @@ void WebAssemblyLowerEmscriptenEHSjLj::rebuildSSA(Function &F) {
     for (Instruction &I : BB) {
       if (I.getType()->isVoidTy())
         continue;
+
+      if (isa<AllocaInst>(&I)) {
+        // If the alloca has any lifetime marker that is no longer dominated
+        // by the alloca, remove all lifetime markers. Lifetime markers must
+        // always work directly on the alloca, and this is no longer possible.
+        bool HasNonDominatedLifetimeMarker = any_of(I.users(), [&](User *U) {
+          auto *UserI = cast<Instruction>(U);
+          return UserI->isLifetimeStartOrEnd() && !DT.dominates(&I, UserI);
+        });
+        if (HasNonDominatedLifetimeMarker) {
+          for (User *U : make_early_inc_range(I.users())) {
+            auto *UserI = cast<Instruction>(U);
+            if (UserI->isLifetimeStartOrEnd())
+              UserI->eraseFromParent();
+          }
+        }
+      }
+
       unsigned VarID = SSA.AddVariable(I.getName(), I.getType());
       // If a value is defined by an invoke instruction, it is only available in
       // its normal destination and not in its unwind destination.
@@ -1269,10 +1287,20 @@ bool WebAssemblyLowerEmscriptenEHSjLj::runSjLjOnFunction(Function &F) {
 
   // Setjmp preparation
 
+  SmallVector<AllocaInst *> StaticAllocas;
+  for (Instruction &I : F.getEntryBlock())
+    if (auto *AI = dyn_cast<AllocaInst>(&I))
+      if (AI->isStaticAlloca())
+        StaticAllocas.push_back(AI);
+
   BasicBlock *Entry = &F.getEntryBlock();
   DebugLoc FirstDL = getOrCreateDebugLoc(&*Entry->begin(), F.getSubprogram());
   SplitBlock(Entry, &*Entry->getFirstInsertionPt());
 
+  // Move static allocas back into the entry block, so they stay static.
+  for (AllocaInst *AI : StaticAllocas)
+    AI->moveBefore(Entry->getTerminator()->getIterator());
+
   IRB.SetInsertPoint(Entry->getTerminator()->getIterator());
   // This alloca'ed pointer is used by the runtime to identify function
   // invocations. It's just for pointer comparisons. It will never be