Add the 'resume' instruction for the new EH rewrite.

This adds the 'resume' instruction class, IR parsing, and bitcode reading and
writing. The 'resume' instruction resumes propagation of an existing (in-flight)
exception whose unwinding was interrupted with a 'landingpad' instruction (to be
added later).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136589 91177308-0d34-0410-b5e6-96231b3b80d8

24 files changed, 257 insertions, 73 deletions

diff --git a/docs/LangRef.html b/docs/LangRef.html
index 6c36ea1..ac527c4 100644
--- a/docs/LangRef.html
+++ b/docs/LangRef.html
@@ -124,6 +124,7 @@
           <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
           <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
           <li><a href="#i_unwind">'<tt>unwind</tt>'  Instruction</a></li>
+          <li><a href="#i_resume">'<tt>resume</tt>'  Instruction</a></li>
           <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
         </ol>
       </li>
@@ -3023,13 +3024,14 @@ should not be exposed to source languages.</p>
    control flow, not values (the one exception being the
    '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
 
-<p>There are seven different terminator instructions: the
+<p>There are eight different terminator instructions: the
    '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
    '<a href="#i_br"><tt>br</tt></a>' instruction, the
    '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
    '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
    '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
-   '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
+   '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, the
+   '<a href="#i_resume"><tt>resume</tt></a>' instruction, and the
    '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
 
 <!-- _______________________________________________________________________ -->
@@ -3350,6 +3352,39 @@ that the invoke/unwind semantics are likely to change in future versions.</p>
 
 </div>
 
+ <!-- _______________________________________________________________________ -->
+ 
+<h4>
+  <a name="i_resume">'<tt>resume</tt>' Instruction</a>
+</h4>
+
+<div>
+
+<h5>Syntax:</h5>
+<pre>
+  resume &lt;type&gt; &lt;value&gt;
+</pre>
+
+<h5>Overview:</h5>
+<p>The '<tt>resume</tt>' instruction is a terminator instruction that has no
+   successors.</p>
+
+<h5>Arguments:</h5>
+<p>The '<tt>resume</tt>' instruction's argument must have the same type as the
+   result of any '<tt>landingpad</tt>' instruction in the same function.</p>
+
+<h5>Semantics:</h5>
+<p>The '<tt>resume</tt>' instruction resumes propagation of an existing
+   (in-flight) exception whose unwinding was interrupted with
+   a landingpad instruction.</p>
+
+<h5>Example:</h5>
+<pre>
+ resume { i8*, i32 } %exn
+</pre>
+
+</div>
+
 <!-- _______________________________________________________________________ -->
 
 <h4>
diff --git a/include/llvm-c/Core.h b/include/llvm-c/Core.h
index 51da662..782b7ea 100644
--- a/include/llvm-c/Core.h
+++ b/include/llvm-c/Core.h
@@ -188,7 +188,10 @@ typedef enum {
   /* Atomic operators */
   LLVMFence          = 55,
   LLVMAtomicCmpXchg  = 56,
-  LLVMAtomicRMW      = 57
+  LLVMAtomicRMW      = 57,
+
+  /* Exception Handling Operators */
+  LLVMResume         = 58
 
 } LLVMOpcode;
 
@@ -477,6 +480,7 @@ LLVMTypeRef LLVMX86MMXType(void);
         macro(SwitchInst)                   \
         macro(UnreachableInst)              \
         macro(UnwindInst)                   \
+        macro(ResumeInst)                   \
     macro(UnaryInstruction)                 \
       macro(AllocaInst)                     \
       macro(CastInst)                       \
@@ -825,6 +829,7 @@ LLVMValueRef LLVMBuildInvoke(LLVMBuilderRef, LLVMValueRef Fn,
                              LLVMBasicBlockRef Then, LLVMBasicBlockRef Catch,
                              const char *Name);
 LLVMValueRef LLVMBuildUnwind(LLVMBuilderRef);
+LLVMValueRef LLVMBuildResume(LLVMBuilderRef B, LLVMValueRef Exn);
 LLVMValueRef LLVMBuildUnreachable(LLVMBuilderRef);
 
 /* Add a case to the switch instruction */
diff --git a/include/llvm/Bitcode/LLVMBitCodes.h b/include/llvm/Bitcode/LLVMBitCodes.h
index 404e3de..92d2c2d 100644
--- a/include/llvm/Bitcode/LLVMBitCodes.h
+++ b/include/llvm/Bitcode/LLVMBitCodes.h
@@ -304,9 +304,10 @@ namespace bitc {
     FUNC_CODE_INST_FENCE       = 36, // FENCE: [ordering, synchscope]
     FUNC_CODE_INST_CMPXCHG     = 37, // CMPXCHG: [ptrty,ptr,cmp,new, align, vol,
                                      //           ordering, synchscope]
-    FUNC_CODE_INST_ATOMICRMW   = 38  // ATOMICRMW: [ptrty,ptr,val, operation,
+    FUNC_CODE_INST_ATOMICRMW   = 38, // ATOMICRMW: [ptrty,ptr,val, operation,
                                      //             align, vol,
                                      //             ordering, synchscope]
+    FUNC_CODE_INST_RESUME      = 39  // RESUME:     [opval]
   };
 } // End bitc namespace
 } // End llvm namespace
diff --git a/include/llvm/Instruction.def b/include/llvm/Instruction.def
index b2c7d63..2e02b67 100644
--- a/include/llvm/Instruction.def
+++ b/include/llvm/Instruction.def
@@ -100,79 +100,79 @@ HANDLE_TERM_INST  ( 3, Switch     , SwitchInst)
 HANDLE_TERM_INST  ( 4, IndirectBr , IndirectBrInst)
 HANDLE_TERM_INST  ( 5, Invoke     , InvokeInst)
 HANDLE_TERM_INST  ( 6, Unwind     , UnwindInst)
-HANDLE_TERM_INST  ( 7, Unreachable, UnreachableInst)
-  LAST_TERM_INST  ( 7)
+HANDLE_TERM_INST  ( 7, Resume     , ResumeInst)
+HANDLE_TERM_INST  ( 8, Unreachable, UnreachableInst)
+  LAST_TERM_INST  ( 8)
 
 // Standard binary operators...
- FIRST_BINARY_INST( 8)
-HANDLE_BINARY_INST( 8, Add  , BinaryOperator)
-HANDLE_BINARY_INST( 9, FAdd  , BinaryOperator)
-HANDLE_BINARY_INST(10, Sub  , BinaryOperator)
-HANDLE_BINARY_INST(11, FSub  , BinaryOperator)
-HANDLE_BINARY_INST(12, Mul  , BinaryOperator)
-HANDLE_BINARY_INST(13, FMul  , BinaryOperator)
-HANDLE_BINARY_INST(14, UDiv , BinaryOperator)
-HANDLE_BINARY_INST(15, SDiv , BinaryOperator)
-HANDLE_BINARY_INST(16, FDiv , BinaryOperator)
-HANDLE_BINARY_INST(17, URem , BinaryOperator)
-HANDLE_BINARY_INST(18, SRem , BinaryOperator)
-HANDLE_BINARY_INST(19, FRem , BinaryOperator)
+ FIRST_BINARY_INST( 9)
+HANDLE_BINARY_INST( 9, Add  , BinaryOperator)
+HANDLE_BINARY_INST(10, FAdd , BinaryOperator)
+HANDLE_BINARY_INST(11, Sub  , BinaryOperator)
+HANDLE_BINARY_INST(12, FSub , BinaryOperator)
+HANDLE_BINARY_INST(13, Mul  , BinaryOperator)
+HANDLE_BINARY_INST(14, FMul , BinaryOperator)
+HANDLE_BINARY_INST(15, UDiv , BinaryOperator)
+HANDLE_BINARY_INST(16, SDiv , BinaryOperator)
+HANDLE_BINARY_INST(17, FDiv , BinaryOperator)
+HANDLE_BINARY_INST(18, URem , BinaryOperator)
+HANDLE_BINARY_INST(19, SRem , BinaryOperator)
+HANDLE_BINARY_INST(20, FRem , BinaryOperator)
 
 // Logical operators (integer operands)
-HANDLE_BINARY_INST(20, Shl  , BinaryOperator) // Shift left  (logical)
-HANDLE_BINARY_INST(21, LShr , BinaryOperator) // Shift right (logical)
-HANDLE_BINARY_INST(22, AShr , BinaryOperator) // Shift right (arithmetic)
-HANDLE_BINARY_INST(23, And  , BinaryOperator)
-HANDLE_BINARY_INST(24, Or   , BinaryOperator)
-HANDLE_BINARY_INST(25, Xor  , BinaryOperator)
-  LAST_BINARY_INST(25)
+HANDLE_BINARY_INST(21, Shl  , BinaryOperator) // Shift left  (logical)
+HANDLE_BINARY_INST(22, LShr , BinaryOperator) // Shift right (logical)
+HANDLE_BINARY_INST(23, AShr , BinaryOperator) // Shift right (arithmetic)
+HANDLE_BINARY_INST(24, And  , BinaryOperator)
+HANDLE_BINARY_INST(25, Or   , BinaryOperator)
+HANDLE_BINARY_INST(26, Xor  , BinaryOperator)
+  LAST_BINARY_INST(26)
 
 // Memory operators...
- FIRST_MEMORY_INST(26)
-HANDLE_MEMORY_INST(26, Alloca, AllocaInst)  // Stack management
-HANDLE_MEMORY_INST(27, Load  , LoadInst  )  // Memory manipulation instrs
-HANDLE_MEMORY_INST(28, Store , StoreInst )
-HANDLE_MEMORY_INST(29, GetElementPtr, GetElementPtrInst)
-HANDLE_MEMORY_INST(30, Fence , FenceInst )
-HANDLE_MEMORY_INST(31, AtomicCmpXchg , AtomicCmpXchgInst )
-HANDLE_MEMORY_INST(32, AtomicRMW , AtomicRMWInst )
-  LAST_MEMORY_INST(32)
+ FIRST_MEMORY_INST(27)
+HANDLE_MEMORY_INST(27, Alloca, AllocaInst)  // Stack management
+HANDLE_MEMORY_INST(28, Load  , LoadInst  )  // Memory manipulation instrs
+HANDLE_MEMORY_INST(29, Store , StoreInst )
+HANDLE_MEMORY_INST(30, GetElementPtr, GetElementPtrInst)
+HANDLE_MEMORY_INST(31, Fence , FenceInst )
+HANDLE_MEMORY_INST(32, AtomicCmpXchg , AtomicCmpXchgInst )
+HANDLE_MEMORY_INST(33, AtomicRMW , AtomicRMWInst )
+  LAST_MEMORY_INST(33)
 
 // Cast operators ...
 // NOTE: The order matters here because CastInst::isEliminableCastPair 
 // NOTE: (see Instructions.cpp) encodes a table based on this ordering.
- FIRST_CAST_INST(33)
-HANDLE_CAST_INST(33, Trunc   , TruncInst   )  // Truncate integers
-HANDLE_CAST_INST(34, ZExt    , ZExtInst    )  // Zero extend integers
-HANDLE_CAST_INST(35, SExt    , SExtInst    )  // Sign extend integers
-HANDLE_CAST_INST(36, FPToUI  , FPToUIInst  )  // floating point -> UInt
-HANDLE_CAST_INST(37, FPToSI  , FPToSIInst  )  // floating point -> SInt
-HANDLE_CAST_INST(38, UIToFP  , UIToFPInst  )  // UInt -> floating point
-HANDLE_CAST_INST(39, SIToFP  , SIToFPInst  )  // SInt -> floating point
-HANDLE_CAST_INST(40, FPTrunc , FPTruncInst )  // Truncate floating point
-HANDLE_CAST_INST(41, FPExt   , FPExtInst   )  // Extend floating point
-HANDLE_CAST_INST(42, PtrToInt, PtrToIntInst)  // Pointer -> Integer
-HANDLE_CAST_INST(43, IntToPtr, IntToPtrInst)  // Integer -> Pointer
-HANDLE_CAST_INST(44, BitCast , BitCastInst )  // Type cast
-  LAST_CAST_INST(44)
+ FIRST_CAST_INST(34)
+HANDLE_CAST_INST(34, Trunc   , TruncInst   )  // Truncate integers
+HANDLE_CAST_INST(35, ZExt    , ZExtInst    )  // Zero extend integers
+HANDLE_CAST_INST(36, SExt    , SExtInst    )  // Sign extend integers
+HANDLE_CAST_INST(37, FPToUI  , FPToUIInst  )  // floating point -> UInt
+HANDLE_CAST_INST(38, FPToSI  , FPToSIInst  )  // floating point -> SInt
+HANDLE_CAST_INST(39, UIToFP  , UIToFPInst  )  // UInt -> floating point
+HANDLE_CAST_INST(40, SIToFP  , SIToFPInst  )  // SInt -> floating point
+HANDLE_CAST_INST(41, FPTrunc , FPTruncInst )  // Truncate floating point
+HANDLE_CAST_INST(42, FPExt   , FPExtInst   )  // Extend floating point
+HANDLE_CAST_INST(43, PtrToInt, PtrToIntInst)  // Pointer -> Integer
+HANDLE_CAST_INST(44, IntToPtr, IntToPtrInst)  // Integer -> Pointer
+HANDLE_CAST_INST(45, BitCast , BitCastInst )  // Type cast
+  LAST_CAST_INST(45)
 
 // Other operators...
- FIRST_OTHER_INST(45)
-HANDLE_OTHER_INST(45, ICmp   , ICmpInst   )  // Integer comparison instruction
-HANDLE_OTHER_INST(46, FCmp   , FCmpInst   )  // Floating point comparison instr.
-HANDLE_OTHER_INST(47, PHI    , PHINode    )  // PHI node instruction
-HANDLE_OTHER_INST(48, Call   , CallInst   )  // Call a function
-HANDLE_OTHER_INST(49, Select , SelectInst )  // select instruction
-HANDLE_OTHER_INST(50, UserOp1, Instruction)  // May be used internally in a pass
-HANDLE_OTHER_INST(51, UserOp2, Instruction)  // Internal to passes only
-HANDLE_OTHER_INST(52, VAArg  , VAArgInst  )  // vaarg instruction
-HANDLE_OTHER_INST(53, ExtractElement, ExtractElementInst)// extract from vector
-HANDLE_OTHER_INST(54, InsertElement, InsertElementInst)  // insert into vector
-HANDLE_OTHER_INST(55, ShuffleVector, ShuffleVectorInst)  // shuffle two vectors.
-HANDLE_OTHER_INST(56, ExtractValue, ExtractValueInst)// extract from aggregate
-HANDLE_OTHER_INST(57, InsertValue, InsertValueInst)  // insert into aggregate
-
-  LAST_OTHER_INST(57)
+ FIRST_OTHER_INST(46)
+HANDLE_OTHER_INST(46, ICmp   , ICmpInst   )  // Integer comparison instruction
+HANDLE_OTHER_INST(47, FCmp   , FCmpInst   )  // Floating point comparison instr.
+HANDLE_OTHER_INST(48, PHI    , PHINode    )  // PHI node instruction
+HANDLE_OTHER_INST(49, Call   , CallInst   )  // Call a function
+HANDLE_OTHER_INST(50, Select , SelectInst )  // select instruction
+HANDLE_OTHER_INST(51, UserOp1, Instruction)  // May be used internally in a pass
+HANDLE_OTHER_INST(52, UserOp2, Instruction)  // Internal to passes only
+HANDLE_OTHER_INST(53, VAArg  , VAArgInst  )  // vaarg instruction
+HANDLE_OTHER_INST(54, ExtractElement, ExtractElementInst)// extract from vector
+HANDLE_OTHER_INST(55, InsertElement, InsertElementInst)  // insert into vector
+HANDLE_OTHER_INST(56, ShuffleVector, ShuffleVectorInst)  // shuffle two vectors.
+HANDLE_OTHER_INST(57, ExtractValue, ExtractValueInst)// extract from aggregate
+HANDLE_OTHER_INST(58, InsertValue, InsertValueInst)  // insert into aggregate
+  LAST_OTHER_INST(58)
 
 #undef  FIRST_TERM_INST
 #undef HANDLE_TERM_INST
diff --git a/include/llvm/Instructions.h b/include/llvm/Instructions.h
index 69538e9..dbbf5f9 100644
--- a/include/llvm/Instructions.h
+++ b/include/llvm/Instructions.h
@@ -2716,6 +2716,57 @@ private:
 };
 
 //===----------------------------------------------------------------------===//
+//                              ResumeInst Class
+//===----------------------------------------------------------------------===//
+
+//===---------------------------------------------------------------------------
+/// ResumeInst - Resume the propagation of an exception.
+///
+class ResumeInst : public TerminatorInst {
+  ResumeInst(const ResumeInst &RI);
+
+  explicit ResumeInst(Value *Exn, Instruction *InsertBefore=0);
+  ResumeInst(Value *Exn, BasicBlock *InsertAtEnd);
+protected:
+  virtual ResumeInst *clone_impl() const;
+public:
+  static ResumeInst *Create(Value *Exn, Instruction *InsertBefore = 0) {
+    return new(1) ResumeInst(Exn, InsertBefore);
+  }
+  static ResumeInst *Create(Value *Exn, BasicBlock *InsertAtEnd) {
+    return new(1) ResumeInst(Exn, InsertAtEnd);
+  }
+
+  /// Provide fast operand accessors
+  DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
+
+  /// Convenience accessor.
+  Value *getValue() const { return Op<0>(); }
+
+  unsigned getNumSuccessors() const { return 0; }
+
+  // Methods for support type inquiry through isa, cast, and dyn_cast:
+  static inline bool classof(const ResumeInst *) { return true; }
+  static inline bool classof(const Instruction *I) {
+    return I->getOpcode() == Instruction::Resume;
+  }
+  static inline bool classof(const Value *V) {
+    return isa<Instruction>(V) && classof(cast<Instruction>(V));
+  }
+private:
+  virtual BasicBlock *getSuccessorV(unsigned idx) const;
+  virtual unsigned getNumSuccessorsV() const;
+  virtual void setSuccessorV(unsigned idx, BasicBlock *B);
+};
+
+template <>
+struct OperandTraits<ResumeInst> :
+    public FixedNumOperandTraits<ResumeInst, 1> {
+};
+
+DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ResumeInst, Value)
+
+//===----------------------------------------------------------------------===//
 //                           UnreachableInst Class
 //===----------------------------------------------------------------------===//
 
diff --git a/include/llvm/Support/IRBuilder.h b/include/llvm/Support/IRBuilder.h
index 87a017d..01244b8 100644
--- a/include/llvm/Support/IRBuilder.h
+++ b/include/llvm/Support/IRBuilder.h
@@ -479,6 +479,10 @@ public:
     return Insert(new UnwindInst(Context));
   }
 
+  ResumeInst *CreateResume(Value *Exn) {
+    return Insert(ResumeInst::Create(Exn));
+  }
+
   UnreachableInst *CreateUnreachable() {
     return Insert(new UnreachableInst(Context));
   }
diff --git a/include/llvm/Support/InstVisitor.h b/include/llvm/Support/InstVisitor.h
index dc29d6a..591de6f 100644
--- a/include/llvm/Support/InstVisitor.h
+++ b/include/llvm/Support/InstVisitor.h
@@ -163,6 +163,7 @@ public:
   RetTy visitIndirectBrInst(IndirectBrInst &I)      { DELEGATE(TerminatorInst);}
   RetTy visitInvokeInst(InvokeInst &I)              { DELEGATE(TerminatorInst);}
   RetTy visitUnwindInst(UnwindInst &I)              { DELEGATE(TerminatorInst);}
+  RetTy visitResumeInst(ResumeInst &I)              { DELEGATE(TerminatorInst);}
   RetTy visitUnreachableInst(UnreachableInst &I)    { DELEGATE(TerminatorInst);}
   RetTy visitICmpInst(ICmpInst &I)                  { DELEGATE(CmpInst);}
   RetTy visitFCmpInst(FCmpInst &I)                  { DELEGATE(CmpInst);}
diff --git a/lib/AsmParser/LLLexer.cpp b/lib/AsmParser/LLLexer.cpp
index 95b40c9..c3a5a4d 100644
--- a/lib/AsmParser/LLLexer.cpp
+++ b/lib/AsmParser/LLLexer.cpp
@@ -636,6 +636,7 @@ lltok::Kind LLLexer::LexIdentifier() {
   INSTKEYWORD(switch,      Switch);
   INSTKEYWORD(indirectbr,  IndirectBr);
   INSTKEYWORD(invoke,      Invoke);
+  INSTKEYWORD(resume,      Resume);
   INSTKEYWORD(unwind,      Unwind);
   INSTKEYWORD(unreachable, Unreachable);
 
diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 4727fac..82fab91 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -2885,6 +2885,7 @@ int LLParser::ParseInstruction(Instruction *&Inst, BasicBlock *BB,
   case lltok::kw_switch:      return ParseSwitch(Inst, PFS);
   case lltok::kw_indirectbr:  return ParseIndirectBr(Inst, PFS);
   case lltok::kw_invoke:      return ParseInvoke(Inst, PFS);
+  case lltok::kw_resume:      return ParseResume(Inst, PFS);
   // Binary Operators.
   case lltok::kw_add:
   case lltok::kw_sub:
@@ -3253,7 +3254,18 @@ bool LLParser::ParseInvoke(Instruction *&Inst, PerFunctionState &PFS) {
   return false;
 }
 
+/// ParseResume
+///   ::= 'resume' TypeAndValue
+bool LLParser::ParseResume(Instruction *&Inst, PerFunctionState &PFS) {
+  Value *Exn; LocTy ExnLoc;
+  LocTy Loc = Lex.getLoc();
+  if (ParseTypeAndValue(Exn, ExnLoc, PFS))
+    return true;
 
+  ResumeInst *RI = ResumeInst::Create(Exn);
+  Inst = RI;
+  return false;
+}
 
 //===----------------------------------------------------------------------===//
 // Binary Operators.
diff --git a/lib/AsmParser/LLParser.h b/lib/AsmParser/LLParser.h
index 2a7210a..df058ed 100644
--- a/lib/AsmParser/LLParser.h
+++ b/lib/AsmParser/LLParser.h
@@ -347,6 +347,7 @@ namespace llvm {
     bool ParseSwitch(Instruction *&Inst, PerFunctionState &PFS);
     bool ParseIndirectBr(Instruction *&Inst, PerFunctionState &PFS);
     bool ParseInvoke(Instruction *&Inst, PerFunctionState &PFS);
+    bool ParseResume(Instruction *&Inst, PerFunctionState &PFS);
 
     bool ParseArithmetic(Instruction *&I, PerFunctionState &PFS, unsigned Opc,
                          unsigned OperandType);
diff --git a/lib/AsmParser/LLToken.h b/lib/AsmParser/LLToken.h
index 75b332b..3da85ad 100644
--- a/lib/AsmParser/LLToken.h
+++ b/lib/AsmParser/LLToken.h
@@ -124,7 +124,7 @@ namespace lltok {
     kw_fptoui, kw_fptosi, kw_inttoptr, kw_ptrtoint, kw_bitcast,
     kw_select, kw_va_arg,
 
-    kw_ret, kw_br, kw_switch, kw_indirectbr, kw_invoke, kw_unwind,
+    kw_ret, kw_br, kw_switch, kw_indirectbr, kw_invoke, kw_unwind, kw_resume,
     kw_unreachable,
 
     kw_alloca, kw_load, kw_store, kw_fence, kw_cmpxchg, kw_atomicrmw,
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index b4f47ad..b4e1050 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -2508,6 +2508,14 @@ bool BitcodeReader::ParseFunctionBody(Function *F) {
       cast<InvokeInst>(I)->setAttributes(PAL);
       break;
     }
+    case bitc::FUNC_CODE_INST_RESUME: { // RESUME: [opval]
+      unsigned Idx = 0;
+      Value *Val = 0;
+      if (getValueTypePair(Record, Idx, NextValueNo, Val))
+        return Error("Invalid RESUME record");
+      I = ResumeInst::Create(Val);
+      break;
+    }
     case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
       I = new UnwindInst(Context);
       InstructionList.push_back(I);
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index dd071d8..9954400 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1143,6 +1143,10 @@ static void WriteInstruction(const Instruction &I, unsigned InstID,
     }
     break;
   }
+  case Instruction::Resume:
+    Code = bitc::FUNC_CODE_INST_RESUME;
+    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
+    break;
   case Instruction::Unwind:
     Code = bitc::FUNC_CODE_INST_UNWIND;
     break;
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 86d32c2..449f87e 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1810,6 +1810,10 @@ void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) {
 void SelectionDAGBuilder::visitUnwind(const UnwindInst &I) {
 }
 
+void SelectionDAGBuilder::visitResume(const ResumeInst &RI) {
+  llvm_unreachable("SelectionDAGBuilder shouldn't visit resume instructions!");
+}
+
 /// handleSmallSwitchCaseRange - Emit a series of specific tests (suitable for
 /// small case ranges).
 bool SelectionDAGBuilder::handleSmallSwitchRange(CaseRec& CR,
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
index aae56ba..050b86f 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
@@ -467,6 +467,7 @@ public:
 private:
   // These all get lowered before this pass.
   void visitInvoke(const InvokeInst &I);
+  void visitResume(const ResumeInst &I);
   void visitUnwind(const UnwindInst &I);
 
   void visitBinary(const User &I, unsigned OpCode);
diff --git a/lib/CodeGen/ShadowStackGC.cpp b/lib/CodeGen/ShadowStackGC.cpp
index 9807c8c..daab89b 100644
--- a/lib/CodeGen/ShadowStackGC.cpp
+++ b/lib/CodeGen/ShadowStackGC.cpp
@@ -113,9 +113,11 @@ namespace {
         while (StateBB != StateE) {
           BasicBlock *CurBB = StateBB++;
 
-          // Branches and invokes do not escape, only unwind and return do.
+          // Branches and invokes do not escape, only unwind, resume, and return
+          // do.
           TerminatorInst *TI = CurBB->getTerminator();
-          if (!isa<UnwindInst>(TI) && !isa<ReturnInst>(TI))
+          if (!isa<UnwindInst>(TI) && !isa<ReturnInst>(TI) &&
+              !isa<ResumeInst>(TI))
             continue;
 
           Builder.SetInsertPoint(TI->getParent(), TI);
diff --git a/lib/Target/CBackend/CBackend.cpp b/lib/Target/CBackend/CBackend.cpp
index 18a27d2..5b9a0a2 100644
--- a/lib/Target/CBackend/CBackend.cpp
+++ b/lib/Target/CBackend/CBackend.cpp
@@ -288,10 +288,12 @@ namespace {
     void visitInvokeInst(InvokeInst &I) {
       llvm_unreachable("Lowerinvoke pass didn't work!");
     }
-
     void visitUnwindInst(UnwindInst &I) {
       llvm_unreachable("Lowerinvoke pass didn't work!");
     }
+    void visitResumeInst(ResumeInst &I) {
+      llvm_unreachable("DwarfEHPrepare pass didn't work!");
+    }
     void visitUnreachableInst(UnreachableInst &I);
 
     void visitPHINode(PHINode &I);
diff --git a/lib/Target/CppBackend/CPPBackend.cpp b/lib/Target/CppBackend/CPPBackend.cpp
index 7f5f5e1..108023d 100644
--- a/lib/Target/CppBackend/CPPBackend.cpp
+++ b/lib/Target/CppBackend/CPPBackend.cpp
@@ -1064,6 +1064,11 @@ void CppWriter::printInstruction(const Instruction *I,
     }
     break;
   }
+  case Instruction::Resume: {
+    Out << "ResumeInst::Create(mod->getContext(), " << opNames[0]
+        << ", " << bbname << ");";
+    break;
+  }
   case Instruction::Invoke: {
     const InvokeInst* inv = cast<InvokeInst>(I);
     Out << "std::vector<Value*> " << iName << "_params;";
diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index 0283568..771a50b 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/lib/Transforms/IPO/GlobalOpt.cpp
@@ -2506,7 +2506,7 @@ static bool EvaluateFunction(Function *F, Constant *&RetVal,
         CallStack.pop_back();  // return from fn.
         return true;  // We succeeded at evaluating this ctor!
       } else {
-        // invoke, unwind, unreachable.
+        // invoke, unwind, resume, unreachable.
         return false;  // Cannot handle this terminator.
       }
 
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index c33dec1..09edc41 100644
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -732,9 +732,11 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
       }
     }
     
-    // If the stack restore is in a return/unwind block and if there are no
-    // allocas or calls between the restore and the return, nuke the restore.
-    if (!CannotRemove && (isa<ReturnInst>(TI) || isa<UnwindInst>(TI)))
+    // If the stack restore is in a return, resume, or unwind block and if there
+    // are no allocas or calls between the restore and the return, nuke the
+    // restore.
+    if (!CannotRemove && (isa<ReturnInst>(TI) || isa<ResumeInst>(TI) ||
+                          isa<UnwindInst>(TI)))
       return EraseInstFromFunction(CI);
     break;
   }
diff --git a/lib/Transforms/Scalar/SCCP.cpp b/lib/Transforms/Scalar/SCCP.cpp
index 749ba40..4e1c274 100644
--- a/lib/Transforms/Scalar/SCCP.cpp
+++ b/lib/Transforms/Scalar/SCCP.cpp
@@ -528,6 +528,7 @@ private:
     visitTerminatorInst(II);
   }
   void visitCallSite      (CallSite CS);
+  void visitResumeInst    (TerminatorInst &I) { /*returns void*/ }
   void visitUnwindInst    (TerminatorInst &I) { /*returns void*/ }
   void visitUnreachableInst(TerminatorInst &I) { /*returns void*/ }
   void visitFenceInst     (FenceInst &I) { /*returns void*/ }
diff --git a/lib/VMCore/Core.cpp b/lib/VMCore/Core.cpp
index 3c93736..ce010c1 100644
--- a/lib/VMCore/Core.cpp
+++ b/lib/VMCore/Core.cpp
@@ -1687,6 +1687,10 @@ LLVMValueRef LLVMBuildUnwind(LLVMBuilderRef B) {
   return wrap(unwrap(B)->CreateUnwind());
 }
 
+LLVMValueRef LLVMBuildResume(LLVMBuilderRef B, LLVMValueRef Exn) {
+  return wrap(unwrap(B)->CreateResume(unwrap(Exn)));
+}
+
 LLVMValueRef LLVMBuildUnreachable(LLVMBuilderRef B) {
   return wrap(unwrap(B)->CreateUnreachable());
 }
diff --git a/lib/VMCore/Instruction.cpp b/lib/VMCore/Instruction.cpp
index c4365fc..216bb35 100644
--- a/lib/VMCore/Instruction.cpp
+++ b/lib/VMCore/Instruction.cpp
@@ -101,6 +101,7 @@ const char *Instruction::getOpcodeName(unsigned OpCode) {
   case Switch: return "switch";
   case IndirectBr: return "indirectbr";
   case Invoke: return "invoke";
+  case Resume: return "resume";
   case Unwind: return "unwind";
   case Unreachable: return "unreachable";
 
diff --git a/lib/VMCore/Instructions.cpp b/lib/VMCore/Instructions.cpp
index 75458ba..c36102d 100644
--- a/lib/VMCore/Instructions.cpp
+++ b/lib/VMCore/Instructions.cpp
@@ -574,6 +574,41 @@ BasicBlock *UnwindInst::getSuccessorV(unsigned idx) const {
 }
 
 //===----------------------------------------------------------------------===//
+//                        ResumeInst Implementation
+//===----------------------------------------------------------------------===//
+
+ResumeInst::ResumeInst(const ResumeInst &RI)
+  : TerminatorInst(Type::getVoidTy(RI.getContext()), Instruction::Resume,
+                   OperandTraits<ResumeInst>::op_begin(this), 1) {
+  Op<0>() = RI.Op<0>();
+}
+
+ResumeInst::ResumeInst(Value *Exn, Instruction *InsertBefore)
+  : TerminatorInst(Type::getVoidTy(Exn->getContext()), Instruction::Resume,
+                   OperandTraits<ResumeInst>::op_begin(this), 1, InsertBefore) {
+  Op<0>() = Exn;
+}
+
+ResumeInst::ResumeInst(Value *Exn, BasicBlock *InsertAtEnd)
+  : TerminatorInst(Type::getVoidTy(Exn->getContext()), Instruction::Resume,
+                   OperandTraits<ResumeInst>::op_begin(this), 1, InsertAtEnd) {
+  Op<0>() = Exn;
+}
+
+unsigned ResumeInst::getNumSuccessorsV() const {
+  return getNumSuccessors();
+}
+
+void ResumeInst::setSuccessorV(unsigned idx, BasicBlock *NewSucc) {
+  llvm_unreachable("ResumeInst has no successors!");
+}
+
+BasicBlock *ResumeInst::getSuccessorV(unsigned idx) const {
+  llvm_unreachable("ResumeInst has no successors!");
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
 //                      UnreachableInst Implementation
 //===----------------------------------------------------------------------===//
 
@@ -3254,6 +3289,10 @@ InvokeInst *InvokeInst::clone_impl() const {
   return new(getNumOperands()) InvokeInst(*this);
 }
 
+ResumeInst *ResumeInst::clone_impl() const {
+  return new(1) ResumeInst(*this);
+}
+
 UnwindInst *UnwindInst::clone_impl() const {
   LLVMContext &Context = getContext();
   return new UnwindInst(Context);