Index: llvm/lib/CodeGen/CodeGenPrepare.cpp
===================================================================
--- llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -413,6 +413,7 @@
 
   void removeAllAssertingVHReferences(Value *V);
   bool eliminateAssumptions(Function &F);
+  bool hoistCatchPadAlloca(Function &F);
   bool eliminateFallThrough(Function &F);
   bool eliminateMostlyEmptyBlocks(Function &F);
   BasicBlock *findDestBlockOfMergeableEmptyBlock(BasicBlock *BB);
@@ -556,7 +557,9 @@
   // blocks, since there might be blocks that only contain @llvm.assume calls
   // (plus arguments that we can get rid of).
   EverMadeChange |= eliminateAssumptions(F);
-
+  // The frame allocator requires catchpad args to be allocated in the entry
+  // block.
+  EverMadeChange |= hoistCatchPadAlloca(F);
   // Eliminate blocks that contain only PHI nodes and an
   // unconditional branch.
   EverMadeChange |= eliminateMostlyEmptyBlocks(F);
@@ -700,6 +703,33 @@
   return EverMadeChange;
 }
 
+// If a catchpad has a local allocated arg which is not allocated in the
+// entry block, hoist it to the entry block.
+bool CodeGenPrepare::hoistCatchPadAlloca(Function &F) {
+  if (!F.hasPersonalityFn())
+    return false;
+  bool MadeChange = false;
+  auto *EntryBlock = &(F.getEntryBlock());
+  for (BasicBlock &BB : F) {
+    CurInstIterator = BB.begin();
+    while (CurInstIterator != BB.end()) {
+      Instruction *I = &*(CurInstIterator++);
+      if (auto *CatchPad = dyn_cast<CatchPadInst>(I)) {
+        for (auto &Arg : CatchPad->arg_operands()) {
+          if (auto *AI = dyn_cast<AllocaInst>(&Arg)) {
+            if (AI->getParent() != EntryBlock) {
+              AI->removeFromParent();
+              AI->insertBefore(&*(EntryBlock->getFirstInsertionPt()));
+              MadeChange = true;
+            }
+          }
+        }
+      }
+    }
+  }
+  return MadeChange;
+}
+
 bool CodeGenPrepare::eliminateAssumptions(Function &F) {
   bool MadeChange = false;
   for (BasicBlock &BB : F) {
Index: llvm/test/Transforms/CodeGenPrepare/catchpad-dynamic-alloca.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/CodeGenPrepare/catchpad-dynamic-alloca.ll
@@ -0,0 +1,83 @@
+; RUN: opt --codegenprepare -S %s | FileCheck %s
+
+target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.28.29334"
+
+%struct.widget = type { ptr, ptr, [8 x i8] }
+
+@global = external global %struct.widget
+
+; CHECK-LABEL: hoist
+; CHECK-NEXT: bb
+; CHECK-NEXT: %tmp = alloca i32
+; CHECK-NEXT: br i1{{.*}}%bb1
+define dso_local void @hoist() local_unnamed_addr #0 personality ptr @__CxxFrameHandler3 {
+bb:
+  br i1 poison, label %bb1, label %bb7
+
+bb1:                                              ; preds = %bb
+  %tmp = alloca i32, align 4
+  invoke void @snork()
+          to label %bb6 unwind label %bb2
+
+bb2:                                              ; preds = %bb1
+  %tmp3 = catchswitch within none [label %bb4] unwind label %bb8
+
+bb4:                                              ; preds = %bb2
+  %tmp5 = catchpad within %tmp3 [ptr @global, i32 0, ptr %tmp]
+  unreachable
+
+bb6:                                              ; preds = %bb1
+  unreachable
+
+bb7:                                              ; preds = %bb
+  ret void
+
+bb8:                                              ; preds = %bb2
+  %tmp9 = cleanuppad within none []
+  unreachable
+}
+
+; tmp2/tmp are in entry block, should not be moved.
+; check that ordering is not changed.
+
+; CHECK-LABEL: nohoist
+; CHECK: bb:
+; CHECK-NEXT: %tmp2 = alloca i32
+; CHECK-NEXT: %tmp = alloca i32
+define dso_local void @nohoist() local_unnamed_addr #0 personality ptr @__CxxFrameHandler3 {
+bb:
+  %tmp2 = alloca i32
+  %tmp = alloca i32, align 4
+  br i1 poison, label %bb1, label %bb7
+
+bb1:                                              ; preds = %bb
+  invoke void @snork()
+          to label %bb6 unwind label %bb2
+
+bb2:                                              ; preds = %bb1
+  %tmp3 = catchswitch within none [label %bb4] unwind label %bb8
+
+bb4:                                              ; preds = %bb2
+  %tmp5 = catchpad within %tmp3 [ptr @global, i32 0, ptr %tmp]
+  unreachable
+
+bb6:                                              ; preds = %bb1
+  unreachable
+
+bb7:                                              ; preds = %bb
+  ret void
+
+bb8:                                              ; preds = %bb2
+  %tmp9 = cleanuppad within none []
+  unreachable
+}
+
+
+; Function Attrs: nofree
+declare dso_local i32 @__CxxFrameHandler3(...) #0
+
+declare dso_local void @snork() local_unnamed_addr #0
+
+attributes #0 = { nofree }
+