1 files changed, 15 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index df900d65cf2..6d0043ba9e0 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -948,6 +948,21 @@ static bool
 simplifyRelocatesOffABase(GCRelocateInst *RelocatedBase,
                           const SmallVectorImpl<GCRelocateInst *> &Targets) {
   bool MadeChange = false;
+  // We must ensure the relocation of derived pointer is defined after
+  // relocation of base pointer. If we find a relocation corresponding to base
+  // defined earlier than relocation of base then we move relocation of base
+  // right before found relocation. We consider only relocation in the same
+  // basic block as relocation of base. Relocations from other basic block will
+  // be skipped by optimization and we do not care about them.
+  for (auto R = RelocatedBase->getParent()->getFirstInsertionPt();
+       &*R != RelocatedBase; ++R)
+    if (auto RI = dyn_cast<GCRelocateInst>(R))
+      if (RI->getStatepoint() == RelocatedBase->getStatepoint())
+        if (RI->getBasePtrIndex() == RelocatedBase->getBasePtrIndex()) {
+          RelocatedBase->moveBefore(RI);
+          break;
+        }
+
   for (GCRelocateInst *ToReplace : Targets) {
     assert(ToReplace->getBasePtrIndex() == RelocatedBase->getBasePtrIndex() &&
            "Not relocating a derived object of the original base object");