Index: include/llvm/Bitcode/LLVMBitCodes.h
===================================================================
--- include/llvm/Bitcode/LLVMBitCodes.h
+++ include/llvm/Bitcode/LLVMBitCodes.h
@@ -506,7 +506,8 @@
     ATTR_KIND_SWIFT_ERROR = 47,
     ATTR_KIND_NO_RECURSE = 48,
     ATTR_KIND_INACCESSIBLEMEM_ONLY = 49,
-    ATTR_KIND_INACCESSIBLEMEM_OR_ARGMEMONLY = 50
+    ATTR_KIND_INACCESSIBLEMEM_OR_ARGMEMONLY = 50,
+    ATTR_KIND_NO_USE_JUMP_TABLE = 51
   };
 
   enum ComdatSelectionKindCodes {
Index: include/llvm/IR/Attributes.td
===================================================================
--- include/llvm/IR/Attributes.td
+++ include/llvm/IR/Attributes.td
@@ -60,6 +60,9 @@
 /// Build jump-instruction tables and replace refs.
 def JumpTable : EnumAttr<"jumptable">;
 
+/// Function body does not use JumpTables
+def NoUseJumpTable : EnumAttr<"nousejumptable">;
+
 /// Function must be optimized for size first.
 def MinSize : EnumAttr<"minsize">;
 
Index: lib/AsmParser/LLLexer.cpp
===================================================================
--- lib/AsmParser/LLLexer.cpp
+++ lib/AsmParser/LLLexer.cpp
@@ -631,6 +631,7 @@
   KEYWORD(nonnull);
   KEYWORD(noredzone);
   KEYWORD(noreturn);
+  KEYWORD(nousejumptable);
   KEYWORD(nounwind);
   KEYWORD(optnone);
   KEYWORD(optsize);
Index: lib/AsmParser/LLParser.cpp
===================================================================
--- lib/AsmParser/LLParser.cpp
+++ lib/AsmParser/LLParser.cpp
@@ -1034,6 +1034,7 @@
     case lltok::kw_noredzone: B.addAttribute(Attribute::NoRedZone); break;
     case lltok::kw_noreturn: B.addAttribute(Attribute::NoReturn); break;
     case lltok::kw_norecurse: B.addAttribute(Attribute::NoRecurse); break;
+    case lltok::kw_nousejumptable: B.addAttribute(Attribute::NoUseJumpTable); break;
     case lltok::kw_nounwind: B.addAttribute(Attribute::NoUnwind); break;
     case lltok::kw_optnone: B.addAttribute(Attribute::OptimizeNone); break;
     case lltok::kw_optsize: B.addAttribute(Attribute::OptimizeForSize); break;
@@ -1363,6 +1364,7 @@
     case lltok::kw_noredzone:
     case lltok::kw_noreturn:
     case lltok::kw_nounwind:
+    case lltok::kw_nousejumptable:
     case lltok::kw_optnone:
     case lltok::kw_optsize:
     case lltok::kw_returns_twice:
@@ -1452,6 +1454,7 @@
     case lltok::kw_noredzone:
     case lltok::kw_noreturn:
     case lltok::kw_nounwind:
+    case lltok::kw_nousejumptable:
     case lltok::kw_optnone:
     case lltok::kw_optsize:
     case lltok::kw_returns_twice:
Index: lib/AsmParser/LLToken.h
===================================================================
--- lib/AsmParser/LLToken.h
+++ lib/AsmParser/LLToken.h
@@ -136,6 +136,7 @@
     kw_nonnull,
     kw_noredzone,
     kw_noreturn,
+    kw_nousejumptable,
     kw_nounwind,
     kw_optnone,
     kw_optsize,
Index: lib/Bitcode/Reader/BitcodeReader.cpp
===================================================================
--- lib/Bitcode/Reader/BitcodeReader.cpp
+++ lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1293,6 +1293,8 @@
     return Attribute::NoReturn;
   case bitc::ATTR_KIND_NO_UNWIND:
     return Attribute::NoUnwind;
+  case bitc::ATTR_KIND_NO_USE_JUMP_TABLE:
+    return Attribute::NoUseJumpTable;
   case bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE:
     return Attribute::OptimizeForSize;
   case bitc::ATTR_KIND_OPTIMIZE_NONE:
Index: lib/Bitcode/Writer/BitcodeWriter.cpp
===================================================================
--- lib/Bitcode/Writer/BitcodeWriter.cpp
+++ lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -228,6 +228,8 @@
     return bitc::ATTR_KIND_NO_RETURN;
   case Attribute::NoUnwind:
     return bitc::ATTR_KIND_NO_UNWIND;
+  case Attribute::NoUseJumpTable:
+    return bitc::ATTR_KIND_NO_USE_JUMP_TABLE;
   case Attribute::OptimizeForSize:
     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
   case Attribute::OptimizeNone:
Index: lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -7927,6 +7927,10 @@
                                          CaseCluster &JTCluster) {
   assert(First <= Last);
 
+  //Give up if function containing SI has NoUseJumpTable attr
+  if (SI->getParent()->getParent()->hasFnAttribute(Attribute::NoUseJumpTable))
+    return false;
+
   auto Prob = BranchProbability::getZero();
   unsigned NumCmps = 0;
   std::vector<MachineBasicBlock*> Table;
Index: lib/IR/Attributes.cpp
===================================================================
--- lib/IR/Attributes.cpp
+++ lib/IR/Attributes.cpp
@@ -237,6 +237,8 @@
     return "norecurse";
   if (hasAttribute(Attribute::NoUnwind))
     return "nounwind";
+  if (hasAttribute(Attribute::NoUseJumpTable))
+    return "nousejumptable";
   if (hasAttribute(Attribute::OptimizeNone))
     return "optnone";
   if (hasAttribute(Attribute::OptimizeForSize))
@@ -448,6 +450,7 @@
   case Attribute::NoRecurse:       return 1ULL << 48;
   case Attribute::InaccessibleMemOnly:         return 1ULL << 49;
   case Attribute::InaccessibleMemOrArgMemOnly: return 1ULL << 50;
+  case Attribute::NoUseJumpTable:       return 1ULL << 51;
   case Attribute::Dereferenceable:
     llvm_unreachable("dereferenceable attribute not supported in raw format");
     break;
Index: lib/IR/Verifier.cpp
===================================================================
--- lib/IR/Verifier.cpp
+++ lib/IR/Verifier.cpp
@@ -1295,6 +1295,7 @@
         I->getKindAsEnum() == Attribute::Cold ||
         I->getKindAsEnum() == Attribute::OptimizeNone ||
         I->getKindAsEnum() == Attribute::JumpTable ||
+        I->getKindAsEnum() == Attribute::NoUseJumpTable ||
         I->getKindAsEnum() == Attribute::Convergent ||
         I->getKindAsEnum() == Attribute::ArgMemOnly ||
         I->getKindAsEnum() == Attribute::NoRecurse ||
Index: lib/Transforms/IPO/ForceFunctionAttrs.cpp
===================================================================
--- lib/Transforms/IPO/ForceFunctionAttrs.cpp
+++ lib/Transforms/IPO/ForceFunctionAttrs.cpp
@@ -43,6 +43,7 @@
       .Case("noredzone", Attribute::NoRedZone)
       .Case("noreturn", Attribute::NoReturn)
       .Case("norecurse", Attribute::NoRecurse)
+      .Case("nousejumptable", Attribute::NoUseJumpTable)
       .Case("nounwind", Attribute::NoUnwind)
       .Case("optnone", Attribute::OptimizeNone)
       .Case("optsize", Attribute::OptimizeForSize)
Index: test/CodeGen/X86/switch.ll
===================================================================
--- test/CodeGen/X86/switch.ll
+++ test/CodeGen/X86/switch.ll
@@ -30,6 +30,23 @@
 ; NOOPT: jmpq
 }
 
+define void @basic_nojumptable(i32 %x) nousejumptable {
+entry:
+  switch i32 %x, label %return [
+    i32 3, label %bb0
+    i32 1, label %bb1
+    i32 4, label %bb1
+    i32 5, label %bb2
+  ]
+bb0: tail call void @g(i32 0) br label %return
+bb1: tail call void @g(i32 1) br label %return
+bb2: tail call void @g(i32 1) br label %return
+return: ret void
+
+; Lowered as a jump table, both with and without optimization.
+; CHECK-LABEL: basic_nojumptable
+; CHECK-NOT: jmpq *.LJTI
+}
 
 define void @simple_ranges(i32 %x) {
 entry: