1 files changed, 9 insertions, 4 deletions
diff --git a/lib/CodeGen/TargetRegisterInfo.cpp b/lib/CodeGen/TargetRegisterInfo.cpp
index 661dc18f7a85..f1b2ecf3243b 100644
--- a/lib/CodeGen/TargetRegisterInfo.cpp
+++ b/lib/CodeGen/TargetRegisterInfo.cpp
@@ -1,9 +1,8 @@
 //==- TargetRegisterInfo.cpp - Target Register Information Implementation --==//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
@@ -14,6 +13,7 @@
 #include "llvm/CodeGen/TargetRegisterInfo.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
@@ -398,6 +398,7 @@ TargetRegisterInfo::getRegAllocationHints(unsigned VirtReg,
   const std::pair<unsigned, SmallVector<unsigned, 4>> &Hints_MRI =
     MRI.getRegAllocationHints(VirtReg);
 
+  SmallSet<unsigned, 32> HintedRegs;
   // First hint may be a target hint.
   bool Skip = (Hints_MRI.first != 0);
   for (auto Reg : Hints_MRI.second) {
@@ -411,6 +412,10 @@ TargetRegisterInfo::getRegAllocationHints(unsigned VirtReg,
     if (VRM && isVirtualRegister(Phys))
       Phys = VRM->getPhys(Phys);
 
+    // Don't add the same reg twice (Hints_MRI may contain multiple virtual
+    // registers allocated to the same physreg).
+    if (!HintedRegs.insert(Phys).second)
+      continue;
     // Check that Phys is a valid hint in VirtReg's register class.
     if (!isPhysicalRegister(Phys))
       continue;