Index: lib/CodeGen/CodeGenPrepare.cpp
===================================================================
--- lib/CodeGen/CodeGenPrepare.cpp
+++ lib/CodeGen/CodeGenPrepare.cpp
@@ -948,6 +948,18 @@
 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. To achieve that we enumerate all GCRelocateInst
+  // up to base relocation.
+  DenseMap<GCRelocateInst *, unsigned> GCRIndex;
+  unsigned CurBaseIdx = 0;
+  for (auto &I : *RelocatedBase->getParent())
+    if (auto RI = dyn_cast<GCRelocateInst>(&I)) {
+      if (RI == RelocatedBase)
+        break;
+      GCRIndex[RI] = CurBaseIdx++;
+    }
+
   for (GCRelocateInst *ToReplace : Targets) {
     assert(ToReplace->getBasePtrIndex() == RelocatedBase->getBasePtrIndex() &&
            "Not relocating a derived object of the original base object");
@@ -963,6 +975,15 @@
       // for each such relocate, so we skip the whole transformation.
       continue;
     }
+    auto It = GCRIndex.find(ToReplace);
+    if (It != GCRIndex.end())
+      if (It->second < CurBaseIdx) {
+        // Relocation of derived pointer is defined earlier than relocation
+        // of the base, so move base right before relocation of derived
+        // pointer.
+        RelocatedBase->moveBefore(ToReplace);
+        CurBaseIdx = It->second;
+      }
 
     Value *Base = ToReplace->getBasePtr();
     auto Derived = dyn_cast<GetElementPtrInst>(ToReplace->getDerivedPtr());
Index: test/Transforms/CodeGenPrepare/statepoint-relocate.ll
===================================================================
--- test/Transforms/CodeGenPrepare/statepoint-relocate.ll
+++ test/Transforms/CodeGenPrepare/statepoint-relocate.ll
@@ -122,6 +122,28 @@
        ret i32 %ret-base
 }
 
+define i32 @test_sor_noop_same_bb(i1 %external-cond, i32* %base) gc "statepoint-example" {
+; CHECK-LABEL: @test_sor_noop_same_bb
+; Here base relocate doesn't dominate derived relocate. Make sure that we don't
+; produce undefined use of the relocated base pointer.
+entry:
+       %ptr1 = getelementptr i32, i32* %base, i32 15
+       ; CHECK: getelementptr i32, i32* %base, i32 15
+       %ptr2 = getelementptr i32, i32* %base, i32 5
+       ; CHECK: getelementptr i32, i32* %base, i32 5
+       %tok = call token (i64, i32, i1 ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_i1f(i64 0, i32 0, i1 ()* @return_i1, i32 0, i32 0, i32 0, i32 0, i32* %base, i32* %ptr1, i32* %ptr2)
+       ; CHECK: call i32* @llvm.experimental.gc.relocate.p0i32(token %tok, i32 7, i32 7)
+       %ptr2-new = call i32* @llvm.experimental.gc.relocate.p0i32(token %tok, i32 7, i32 9)
+       %ret2-new = load i32, i32* %ptr2-new
+       ; CHECK: getelementptr i32, i32* %base-new, i32 5
+       %ptr1-new = call i32* @llvm.experimental.gc.relocate.p0i32(token %tok, i32 7, i32 8)
+       %ret1-new = load i32, i32* %ptr1-new
+       ; CHECK: getelementptr i32, i32* %base-new, i32 15
+       %base-new = call i32* @llvm.experimental.gc.relocate.p0i32(token %tok, i32 7, i32 7)
+       %ret-new = add i32 %ret2-new, %ret1-new
+       ret i32 %ret-new
+}
+
 declare token @llvm.experimental.gc.statepoint.p0f_i1f(i64, i32, i1 ()*, i32, i32, ...)
 declare i32* @llvm.experimental.gc.relocate.p0i32(token, i32, i32)
 declare [3 x i32]* @llvm.experimental.gc.relocate.p0a3i32(token, i32, i32)