clang support gnu asm goto.

Syntax:
  asm [volatile] goto ( AssemblerTemplate
                      :
                      : InputOperands
                      : Clobbers
                      : GotoLabels)

https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html

New llvm IR is "callbr" for inline asm goto instead "call" for inline asm
For:
asm goto("testl %0, %0; jne %l1;" :: "r"(cond)::label_true, loop);
IR:
callbr void asm sideeffect "testl $0, $0; jne ${1:l};", "r,X,X,~{dirflag},~{fpsr},~{flags}"(i32 %0, i8* blockaddress(@foo, %label_true), i8* blockaddress(@foo, %loop)) #1
          to label %asm.fallthrough [label %label_true, label %loop], !srcloc !3

asm.fallthrough:                                

Compiler need to generate:
1> a dummy constarint 'X' for each label.
2> an unique fallthrough label for each asm goto stmt " asm.fallthrough%number".


Diagnostic 
1>	duplicate asm operand name are used in output, input and label.
2>	goto out of scope.

llvm-svn: 362045

clang/include/clang/AST/Stmt.h

@@ -46,6 +46,7 @@ class Attr;
 class CapturedDecl;
 class Decl;
 class Expr;
+class AddrLabelExpr;
 class LabelDecl;
 class ODRHash;
 class PrinterHelper;
@@ -2816,13 +2817,15 @@ class GCCAsmStmt : public AsmStmt {
   StringLiteral **Constraints = nullptr;
   StringLiteral **Clobbers = nullptr;
   IdentifierInfo **Names = nullptr;
+  unsigned NumLabels = 0;
 
 public:
   GCCAsmStmt(const ASTContext &C, SourceLocation asmloc, bool issimple,
              bool isvolatile, unsigned numoutputs, unsigned numinputs,
              IdentifierInfo **names, StringLiteral **constraints, Expr **exprs,
              StringLiteral *asmstr, unsigned numclobbers,
-             StringLiteral **clobbers, SourceLocation rparenloc);
+             StringLiteral **clobbers, unsigned numlabels,
+             SourceLocation rparenloc);
 
   /// Build an empty inline-assembly statement.
   explicit GCCAsmStmt(EmptyShell Empty) : AsmStmt(GCCAsmStmtClass, Empty) {}
@@ -2947,6 +2950,51 @@ public:
     return const_cast<GCCAsmStmt*>(this)->getInputExpr(i);
   }
 
+  //===--- Labels ---===//
+
+  bool isAsmGoto() const {
+    return NumLabels > 0;
+  }
+
+  unsigned getNumLabels() const {
+    return NumLabels;
+  }
+
+  IdentifierInfo *getLabelIdentifier(unsigned i) const {
+    return Names[i + NumInputs];
+  }
+
+  AddrLabelExpr *getLabelExpr(unsigned i) const;
+  StringRef getLabelName(unsigned i) const;
+  using labels_iterator = CastIterator<AddrLabelExpr>;
+  using const_labels_iterator = ConstCastIterator<AddrLabelExpr>;
+  using labels_range = llvm::iterator_range<labels_iterator>;
+  using labels_const_range = llvm::iterator_range<const_labels_iterator>;
+
+  labels_iterator begin_labels() {
+    return &Exprs[0] + NumInputs;
+  }
+
+  labels_iterator end_labels() {
+    return &Exprs[0] + NumInputs + NumLabels;
+  }
+
+  labels_range labels() {
+    return labels_range(begin_labels(), end_labels());
+  }
+
+  const_labels_iterator begin_labels() const {
+    return &Exprs[0] + NumInputs;
+  }
+
+  const_labels_iterator end_labels() const {
+    return &Exprs[0] + NumInputs + NumLabels;
+  }
+
+  labels_const_range labels() const {
+    return labels_const_range(begin_labels(), end_labels());
+  }
+
 private:
   void setOutputsAndInputsAndClobbers(const ASTContext &C,
                                       IdentifierInfo **Names,
@@ -2954,6 +3002,7 @@ private:
                                       Stmt **Exprs,
                                       unsigned NumOutputs,
                                       unsigned NumInputs,
+                                      unsigned NumLabels,
                                       StringLiteral **Clobbers,
                                       unsigned NumClobbers);
 

clang/include/clang/Basic/DiagnosticParseKinds.td

@@ -27,8 +27,8 @@ def err_msasm_unable_to_create_target : Error<
   "MS-style inline assembly is not available: %0">;
 def err_gnu_inline_asm_disabled : Error<
   "GNU-style inline assembly is disabled">;
-def err_asm_goto_not_supported_yet : Error<
+def err_asm_goto_cannot_have_output : Error<
-  "'asm goto' constructs are not supported yet">;
+  "'asm goto' cannot have output constraints">;
 }
 
 let CategoryName = "Parse Issue" in {

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -5064,12 +5064,12 @@ def warn_cxx98_compat_switch_into_protected_scope : Warning<
 def err_indirect_goto_without_addrlabel : Error<
   "indirect goto in function with no address-of-label expressions">;
 def err_indirect_goto_in_protected_scope : Error<
-  "cannot jump from this indirect goto statement to one of its possible targets">;
+  "cannot jump from this %select{indirect|asm}0 goto statement to one of its possible targets">;
 def warn_cxx98_compat_indirect_goto_in_protected_scope : Warning<
-  "jump from this indirect goto statement to one of its possible targets "
+  "jump from this %select{indirect|asm}0 goto statement to one of its possible targets "
   "is incompatible with C++98">, InGroup<CXX98Compat>, DefaultIgnore;
 def note_indirect_goto_target : Note<
-  "possible target of indirect goto statement">;
+  "possible target of %select{indirect|asm}0 goto statement">;
 def note_protected_by_variable_init : Note<
   "jump bypasses variable initialization">;
 def note_protected_by_variable_nontriv_destructor : Note<
@@ -7497,6 +7497,10 @@ let CategoryName = "Inline Assembly Issue" in {
     "use constraint modifier \"%0\"">;
   def note_asm_input_duplicate_first : Note<
     "constraint '%0' is already present here">;
+ def error_duplicate_asm_operand_name : Error<
+    "duplicate use of asm operand name \"%0\"">;
+ def note_duplicate_asm_operand_name : Note<
+    "asm operand name \"%0\" first referenced here">;
 }
 
   def error_inoutput_conflict_with_clobber : Error<

clang/include/clang/Sema/Sema.h

@@ -3971,6 +3971,7 @@ public:
                              unsigned NumInputs, IdentifierInfo **Names,
                              MultiExprArg Constraints, MultiExprArg Exprs,
                              Expr *AsmString, MultiExprArg Clobbers,
+                             unsigned NumLabels,
                              SourceLocation RParenLoc);
 
   void FillInlineAsmIdentifierInfo(Expr *Res,

clang/lib/AST/ASTImporter.cpp

@@ -5592,12 +5592,17 @@ ExpectedStmt ASTNodeImporter::VisitGCCAsmStmt(GCCAsmStmt *S) {
       return InputOrErr.takeError();
   }
 
-  SmallVector<Expr *, 4> Exprs(S->getNumOutputs() + S->getNumInputs());
+  SmallVector<Expr *, 4> Exprs(S->getNumOutputs() + S->getNumInputs() +
+                               S->getNumLabels());
   if (Error Err = ImportContainerChecked(S->outputs(), Exprs))
     return std::move(Err);
 
+  if (Error Err =
+          ImportArrayChecked(S->inputs(), Exprs.begin() + S->getNumOutputs()))
+    return std::move(Err);
+
   if (Error Err = ImportArrayChecked(
-      S->inputs(), Exprs.begin() + S->getNumOutputs()))
+          S->labels(), Exprs.begin() + S->getNumOutputs() + S->getNumInputs()))
     return std::move(Err);
 
   ExpectedSLoc AsmLocOrErr = import(S->getAsmLoc());
@@ -5623,6 +5628,7 @@ ExpectedStmt ASTNodeImporter::VisitGCCAsmStmt(GCCAsmStmt *S) {
       *AsmStrOrErr,
       S->getNumClobbers(),
       Clobbers.data(),
+      S->getNumLabels(),
       *RParenLocOrErr);
 }
 

clang/lib/AST/Stmt.cpp

@@ -444,6 +444,14 @@ void GCCAsmStmt::setInputExpr(unsigned i, Expr *E) {
   Exprs[i + NumOutputs] = E;
 }
 
+AddrLabelExpr *GCCAsmStmt::getLabelExpr(unsigned i) const {
+  return cast<AddrLabelExpr>(Exprs[i + NumInputs]);
+}
+
+StringRef GCCAsmStmt::getLabelName(unsigned i) const {
+  return getLabelExpr(i)->getLabel()->getName();
+}
+
 /// getInputConstraint - Return the specified input constraint.  Unlike output
 /// constraints, these can be empty.
 StringRef GCCAsmStmt::getInputConstraint(unsigned i) const {
@@ -456,13 +464,16 @@ void GCCAsmStmt::setOutputsAndInputsAndClobbers(const ASTContext &C,
                                                 Stmt **Exprs,
                                                 unsigned NumOutputs,
                                                 unsigned NumInputs,
+                                                unsigned NumLabels,
                                                 StringLiteral **Clobbers,
                                                 unsigned NumClobbers) {
   this->NumOutputs = NumOutputs;
   this->NumInputs = NumInputs;
   this->NumClobbers = NumClobbers;
+  this->NumLabels = NumLabels;
+  assert(!(NumOutputs && NumLabels) && "asm goto cannot have outputs");
 
-  unsigned NumExprs = NumOutputs + NumInputs;
+  unsigned NumExprs = NumOutputs + NumInputs + NumLabels;
 
   C.Deallocate(this->Names);
   this->Names = new (C) IdentifierInfo*[NumExprs];
@@ -497,6 +508,10 @@ int GCCAsmStmt::getNamedOperand(StringRef SymbolicName) const {
     if (getInputName(i) == SymbolicName)
       return getNumOutputs() + NumPlusOperands + i;
 
+  for (unsigned i = 0, e = getNumLabels(); i != e; ++i)
+    if (getLabelName(i) == SymbolicName)
+      return i + getNumInputs();
+
   // Not found.
   return -1;
 }
@@ -614,8 +629,8 @@ unsigned GCCAsmStmt::AnalyzeAsmString(SmallVectorImpl<AsmStringPiece>&Pieces,
       while (CurPtr != StrEnd && isDigit(*CurPtr))
         N = N*10 + ((*CurPtr++)-'0');
 
-      unsigned NumOperands =
+      unsigned NumOperands = getNumOutputs() + getNumPlusOperands() +
-        getNumOutputs() + getNumPlusOperands() + getNumInputs();
+                             getNumInputs() + getNumLabels();
       if (N >= NumOperands) {
         DiagOffs = CurPtr-StrStart-1;
         return diag::err_asm_invalid_operand_number;
@@ -728,10 +743,12 @@ GCCAsmStmt::GCCAsmStmt(const ASTContext &C, SourceLocation asmloc,
                        unsigned numinputs, IdentifierInfo **names,
                        StringLiteral **constraints, Expr **exprs,
                        StringLiteral *asmstr, unsigned numclobbers,
-                       StringLiteral **clobbers, SourceLocation rparenloc)
+                       StringLiteral **clobbers, unsigned numlabels,
+                       SourceLocation rparenloc)
     : AsmStmt(GCCAsmStmtClass, asmloc, issimple, isvolatile, numoutputs,
-              numinputs, numclobbers), RParenLoc(rparenloc), AsmStr(asmstr) {
+              numinputs, numclobbers),
-  unsigned NumExprs = NumOutputs + NumInputs;
+              RParenLoc(rparenloc), AsmStr(asmstr), NumLabels(numlabels) {
+  unsigned NumExprs = NumOutputs + NumInputs + NumLabels;
 
   Names = new (C) IdentifierInfo*[NumExprs];
   std::copy(names, names + NumExprs, Names);

clang/lib/AST/StmtPrinter.cpp

@@ -414,12 +414,15 @@ void StmtPrinter::VisitGCCAsmStmt(GCCAsmStmt *Node) {
   if (Node->isVolatile())
     OS << "volatile ";
 
+  if (Node->isAsmGoto())
+    OS << "goto ";
+
   OS << "(";
   VisitStringLiteral(Node->getAsmString());
 
   // Outputs
   if (Node->getNumOutputs() != 0 || Node->getNumInputs() != 0 ||
-      Node->getNumClobbers() != 0)
+      Node->getNumClobbers() != 0 || Node->getNumLabels() != 0)
     OS << " : ";
 
   for (unsigned i = 0, e = Node->getNumOutputs(); i != e; ++i) {
@@ -439,7 +442,8 @@ void StmtPrinter::VisitGCCAsmStmt(GCCAsmStmt *Node) {
   }
 
   // Inputs
-  if (Node->getNumInputs() != 0 || Node->getNumClobbers() != 0)
+  if (Node->getNumInputs() != 0 || Node->getNumClobbers() != 0 ||
+      Node->getNumLabels() != 0)
     OS << " : ";
 
   for (unsigned i = 0, e = Node->getNumInputs(); i != e; ++i) {
@@ -459,7 +463,7 @@ void StmtPrinter::VisitGCCAsmStmt(GCCAsmStmt *Node) {
   }
 
   // Clobbers
-  if (Node->getNumClobbers() != 0)
+  if (Node->getNumClobbers() != 0 || Node->getNumLabels())
     OS << " : ";
 
   for (unsigned i = 0, e = Node->getNumClobbers(); i != e; ++i) {
@@ -469,6 +473,16 @@ void StmtPrinter::VisitGCCAsmStmt(GCCAsmStmt *Node) {
     VisitStringLiteral(Node->getClobberStringLiteral(i));
   }
 
+  // Labels
+  if (Node->getNumLabels() != 0)
+    OS << " : ";
+
+  for (unsigned i = 0, e = Node->getNumLabels(); i != e; ++i) {
+    if (i != 0)
+      OS << ", ";
+    OS << Node->getLabelName(i);
+  }
+
   OS << ");";
   if (Policy.IncludeNewlines) OS << NL;
 }

clang/lib/AST/StmtProfile.cpp

@@ -321,6 +321,9 @@ void StmtProfiler::VisitGCCAsmStmt(const GCCAsmStmt *S) {
   ID.AddInteger(S->getNumClobbers());
   for (unsigned I = 0, N = S->getNumClobbers(); I != N; ++I)
     VisitStringLiteral(S->getClobberStringLiteral(I));
+  ID.AddInteger(S->getNumLabels());
+  for (auto *L : S->labels())
+    VisitDecl(L->getLabel());
 }
 
 void StmtProfiler::VisitMSAsmStmt(const MSAsmStmt *S) {

clang/lib/Analysis/CFG.cpp

@@ -549,6 +549,7 @@ private:
   CFGBlock *VisitExprWithCleanups(ExprWithCleanups *E, AddStmtChoice asc);
   CFGBlock *VisitForStmt(ForStmt *F);
   CFGBlock *VisitGotoStmt(GotoStmt *G);
+  CFGBlock *VisitGCCAsmStmt(GCCAsmStmt *G, AddStmtChoice asc);
   CFGBlock *VisitIfStmt(IfStmt *I);
   CFGBlock *VisitImplicitCastExpr(ImplicitCastExpr *E, AddStmtChoice asc);
   CFGBlock *VisitConstantExpr(ConstantExpr *E, AddStmtChoice asc);
@@ -1478,22 +1479,38 @@ std::unique_ptr<CFG> CFGBuilder::buildCFG(const Decl *D, Stmt *Statement) {
                                    E = BackpatchBlocks.end(); I != E; ++I ) {
 
     CFGBlock *B = I->block;
-    const GotoStmt *G = cast<GotoStmt>(B->getTerminator());
+    if (auto *G = dyn_cast<GotoStmt>(B->getTerminator())) {
-    LabelMapTy::iterator LI = LabelMap.find(G->getLabel());
+      LabelMapTy::iterator LI = LabelMap.find(G->getLabel());
-
+      // If there is no target for the goto, then we are looking at an
-    // If there is no target for the goto, then we are looking at an
+      // incomplete AST.  Handle this by not registering a successor.
-    // incomplete AST.  Handle this by not registering a successor.
+      if (LI == LabelMap.end())
-    if (LI == LabelMap.end()) continue;
+        continue;
-
+      JumpTarget JT = LI->second;
-    JumpTarget JT = LI->second;
+      prependAutomaticObjLifetimeWithTerminator(B, I->scopePosition,
-    prependAutomaticObjLifetimeWithTerminator(B, I->scopePosition,
+                                                JT.scopePosition);
-                                              JT.scopePosition);
+      prependAutomaticObjDtorsWithTerminator(B, I->scopePosition,
-    prependAutomaticObjDtorsWithTerminator(B, I->scopePosition,
+                                             JT.scopePosition);
-                                           JT.scopePosition);
+      const VarDecl *VD = prependAutomaticObjScopeEndWithTerminator(
-    const VarDecl *VD = prependAutomaticObjScopeEndWithTerminator(
+          B, I->scopePosition, JT.scopePosition);
-        B, I->scopePosition, JT.scopePosition);
+      appendScopeBegin(JT.block, VD, G);
-    appendScopeBegin(JT.block, VD, G);
+      addSuccessor(B, JT.block);
-    addSuccessor(B, JT.block);
+    };
+    if (auto *G = dyn_cast<GCCAsmStmt>(B->getTerminator())) {
+      CFGBlock *Successor  = (I+1)->block;
+      for (auto *L : G->labels()) {
+        LabelMapTy::iterator LI = LabelMap.find(L->getLabel());
+        // If there is no target for the goto, then we are looking at an
+        // incomplete AST.  Handle this by not registering a successor.
+        if (LI == LabelMap.end())
+          continue;
+        JumpTarget JT = LI->second;
+        // Successor has been added, so skip it.
+        if (JT.block == Successor)
+          continue;
+        addSuccessor(B, JT.block);
+      }
+      I++;
+    }
   }
 
   // Add successors to the Indirect Goto Dispatch block (if we have one).
@@ -2142,6 +2159,9 @@ CFGBlock *CFGBuilder::Visit(Stmt * S, AddStmtChoice asc) {
     case Stmt::GotoStmtClass:
       return VisitGotoStmt(cast<GotoStmt>(S));
 
+    case Stmt::GCCAsmStmtClass:
+      return VisitGCCAsmStmt(cast<GCCAsmStmt>(S), asc);
+
     case Stmt::IfStmtClass:
       return VisitIfStmt(cast<IfStmt>(S));
 
@@ -3146,6 +3166,28 @@ CFGBlock *CFGBuilder::VisitGotoStmt(GotoStmt *G) {
   return Block;
 }
 
+CFGBlock *CFGBuilder::VisitGCCAsmStmt(GCCAsmStmt *G, AddStmtChoice asc) {
+  // Goto is a control-flow statement.  Thus we stop processing the current
+  // block and create a new one.
+
+  if (!G->isAsmGoto())
+    return VisitStmt(G, asc);
+
+  if (Block) {
+    Succ = Block;
+    if (badCFG)
+      return nullptr;
+  }
+  Block = createBlock();
+  Block->setTerminator(G);
+  // We will backpatch this block later for all the labels.
+  BackpatchBlocks.push_back(JumpSource(Block, ScopePos));
+  // Save "Succ" in BackpatchBlocks. In the backpatch processing, "Succ" is
+  // used to avoid adding "Succ" again.
+  BackpatchBlocks.push_back(JumpSource(Succ, ScopePos));
+  return Block;
+}
+
 CFGBlock *CFGBuilder::VisitForStmt(ForStmt *F) {
   CFGBlock *LoopSuccessor = nullptr;
 

clang/lib/CodeGen/CGStmt.cpp

@@ -1896,6 +1896,55 @@ static llvm::MDNode *getAsmSrcLocInfo(const StringLiteral *Str,
   return llvm::MDNode::get(CGF.getLLVMContext(), Locs);
 }
 
+static void UpdateAsmCallInst(llvm::CallBase &Result, bool HasSideEffect,
+                              bool ReadOnly, bool ReadNone, const AsmStmt &S,
+                              const std::vector<llvm::Type *> &ResultRegTypes,
+                              CodeGenFunction &CGF,
+                              std::vector<llvm::Value *> &RegResults) {
+  Result.addAttribute(llvm::AttributeList::FunctionIndex,
+                      llvm::Attribute::NoUnwind);
+  // Attach readnone and readonly attributes.
+  if (!HasSideEffect) {
+    if (ReadNone)
+      Result.addAttribute(llvm::AttributeList::FunctionIndex,
+                          llvm::Attribute::ReadNone);
+    else if (ReadOnly)
+      Result.addAttribute(llvm::AttributeList::FunctionIndex,
+                          llvm::Attribute::ReadOnly);
+  }
+
+  // Slap the source location of the inline asm into a !srcloc metadata on the
+  // call.
+  if (const auto *gccAsmStmt = dyn_cast<GCCAsmStmt>(&S))
+    Result.setMetadata("srcloc",
+                       getAsmSrcLocInfo(gccAsmStmt->getAsmString(), CGF));
+  else {
+    // At least put the line number on MS inline asm blobs.
+    llvm::Constant *Loc = llvm::ConstantInt::get(CGF.Int32Ty,
+                                        S.getAsmLoc().getRawEncoding());
+    Result.setMetadata("srcloc",
+                       llvm::MDNode::get(CGF.getLLVMContext(),
+                                         llvm::ConstantAsMetadata::get(Loc)));
+  }
+
+  if (CGF.getLangOpts().assumeFunctionsAreConvergent())
+    // Conservatively, mark all inline asm blocks in CUDA or OpenCL as
+    // convergent (meaning, they may call an intrinsically convergent op, such
+    // as bar.sync, and so can't have certain optimizations applied around
+    // them).
+    Result.addAttribute(llvm::AttributeList::FunctionIndex,
+                        llvm::Attribute::Convergent);
+  // Extract all of the register value results from the asm.
+  if (ResultRegTypes.size() == 1) {
+    RegResults.push_back(&Result);
+  } else {
+    for (unsigned i = 0, e = ResultRegTypes.size(); i != e; ++i) {
+      llvm::Value *Tmp = CGF.Builder.CreateExtractValue(&Result, i, "asmresult");
+      RegResults.push_back(Tmp);
+    }
+  }
+}
+
 void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
   // Assemble the final asm string.
   std::string AsmString = S.generateAsmString(getContext());
@@ -2138,6 +2187,29 @@ void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
   }
   Constraints += InOutConstraints;
 
+  // Labels
+  SmallVector<llvm::BasicBlock *, 16> Transfer;
+  llvm::BasicBlock *Fallthrough = nullptr;
+  bool IsGCCAsmGoto = false;
+  if (const auto *GS =  dyn_cast<GCCAsmStmt>(&S)) {
+    IsGCCAsmGoto = GS->isAsmGoto();
+    if (IsGCCAsmGoto) {
+      for (auto *E : GS->labels()) {
+        JumpDest Dest = getJumpDestForLabel(E->getLabel());
+        Transfer.push_back(Dest.getBlock());
+        llvm::BlockAddress *BA =
+            llvm::BlockAddress::get(CurFn, Dest.getBlock());
+        Args.push_back(BA);
+        ArgTypes.push_back(BA->getType());
+        if (!Constraints.empty())
+          Constraints += ',';
+        Constraints += 'X';
+      }
+      StringRef Name = "asm.fallthrough";
+      Fallthrough = createBasicBlock(Name);
+    }
+  }
+
   // Clobbers
   for (unsigned i = 0, e = S.getNumClobbers(); i != e; i++) {
     StringRef Clobber = S.getClobber(i);
@@ -2180,52 +2252,18 @@ void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
   llvm::InlineAsm *IA =
     llvm::InlineAsm::get(FTy, AsmString, Constraints, HasSideEffect,
                          /* IsAlignStack */ false, AsmDialect);
-  llvm::CallInst *Result =
-      Builder.CreateCall(IA, Args, getBundlesForFunclet(IA));
-  Result->addAttribute(llvm::AttributeList::FunctionIndex,
-                       llvm::Attribute::NoUnwind);
-
-  // Attach readnone and readonly attributes.
-  if (!HasSideEffect) {
-    if (ReadNone)
-      Result->addAttribute(llvm::AttributeList::FunctionIndex,
-                           llvm::Attribute::ReadNone);
-    else if (ReadOnly)
-      Result->addAttribute(llvm::AttributeList::FunctionIndex,
-                           llvm::Attribute::ReadOnly);
-  }
-
-  // Slap the source location of the inline asm into a !srcloc metadata on the
-  // call.
-  if (const GCCAsmStmt *gccAsmStmt = dyn_cast<GCCAsmStmt>(&S)) {
-    Result->setMetadata("srcloc", getAsmSrcLocInfo(gccAsmStmt->getAsmString(),
-                                                   *this));
-  } else {
-    // At least put the line number on MS inline asm blobs.
-    auto Loc = llvm::ConstantInt::get(Int32Ty, S.getAsmLoc().getRawEncoding());
-    Result->setMetadata("srcloc",
-                        llvm::MDNode::get(getLLVMContext(),
-                                          llvm::ConstantAsMetadata::get(Loc)));
-  }
-
-  if (getLangOpts().assumeFunctionsAreConvergent()) {
-    // Conservatively, mark all inline asm blocks in CUDA or OpenCL as
-    // convergent (meaning, they may call an intrinsically convergent op, such
-    // as bar.sync, and so can't have certain optimizations applied around
-    // them).
-    Result->addAttribute(llvm::AttributeList::FunctionIndex,
-                         llvm::Attribute::Convergent);
-  }
-
-  // Extract all of the register value results from the asm.
   std::vector<llvm::Value*> RegResults;
-  if (ResultRegTypes.size() == 1) {
+  if (IsGCCAsmGoto) {
-    RegResults.push_back(Result);
+    llvm::CallBrInst *Result =
+        Builder.CreateCallBr(IA, Fallthrough, Transfer, Args);
+    UpdateAsmCallInst(cast<llvm::CallBase>(*Result), HasSideEffect, ReadOnly,
+                      ReadNone, S, ResultRegTypes, *this, RegResults);
+    EmitBlock(Fallthrough);
   } else {
-    for (unsigned i = 0, e = ResultRegTypes.size(); i != e; ++i) {
+    llvm::CallInst *Result =
-      llvm::Value *Tmp = Builder.CreateExtractValue(Result, i, "asmresult");
+        Builder.CreateCall(IA, Args, getBundlesForFunclet(IA));
-      RegResults.push_back(Tmp);
+    UpdateAsmCallInst(cast<llvm::CallBase>(*Result), HasSideEffect, ReadOnly,
-    }
+                      ReadNone, S, ResultRegTypes, *this, RegResults);
   }
 
   assert(RegResults.size() == ResultRegTypes.size());

clang/lib/Parse/ParseStmtAsm.cpp

@@ -710,12 +710,12 @@ StmtResult Parser::ParseAsmStatement(bool &msAsm) {
 
   // Remember if this was a volatile asm.
   bool isVolatile = DS.getTypeQualifiers() & DeclSpec::TQ_volatile;
+  // Remember if this was a goto asm.
+  bool isGotoAsm = false;
 
-  // TODO: support "asm goto" constructs (PR#9295).
   if (Tok.is(tok::kw_goto)) {
-    Diag(Tok, diag::err_asm_goto_not_supported_yet);
+    isGotoAsm = true;
-    SkipUntil(tok::r_paren, StopAtSemi);
+    ConsumeToken();
-    return StmtError();
   }
 
   if (Tok.isNot(tok::l_paren)) {
@@ -753,7 +753,8 @@ StmtResult Parser::ParseAsmStatement(bool &msAsm) {
     return Actions.ActOnGCCAsmStmt(AsmLoc, /*isSimple*/ true, isVolatile,
                                    /*NumOutputs*/ 0, /*NumInputs*/ 0, nullptr,
                                    Constraints, Exprs, AsmString.get(),
-                                   Clobbers, T.getCloseLocation());
+                                   Clobbers, /*NumLabels*/ 0,
+                                   T.getCloseLocation());
   }
 
   // Parse Outputs, if present.
@@ -763,6 +764,12 @@ StmtResult Parser::ParseAsmStatement(bool &msAsm) {
     AteExtraColon = Tok.is(tok::coloncolon);
     ConsumeToken();
 
+    if (!AteExtraColon && isGotoAsm && Tok.isNot(tok::colon)) {
+      Diag(Tok, diag::err_asm_goto_cannot_have_output);
+      SkipUntil(tok::r_paren, StopAtSemi);
+      return StmtError();
+    }
+
     if (!AteExtraColon && ParseAsmOperandsOpt(Names, Constraints, Exprs))
       return StmtError();
   }
@@ -789,12 +796,15 @@ StmtResult Parser::ParseAsmStatement(bool &msAsm) {
   unsigned NumInputs = Names.size() - NumOutputs;
 
   // Parse the clobbers, if present.
-  if (AteExtraColon || Tok.is(tok::colon)) {
+  if (AteExtraColon || Tok.is(tok::colon) || Tok.is(tok::coloncolon)) {
-    if (!AteExtraColon)
+    if (AteExtraColon)
+      AteExtraColon = false;
+    else {
+      AteExtraColon = Tok.is(tok::coloncolon);
       ConsumeToken();
-
+    }
     // Parse the asm-string list for clobbers if present.
-    if (Tok.isNot(tok::r_paren)) {
+    if (!AteExtraColon && isTokenStringLiteral()) {
       while (1) {
         ExprResult Clobber(ParseAsmStringLiteral());
 
@@ -808,11 +818,49 @@ StmtResult Parser::ParseAsmStatement(bool &msAsm) {
       }
     }
   }
+  if (!isGotoAsm && (Tok.isNot(tok::r_paren) || AteExtraColon)) {
+    Diag(Tok, diag::err_expected) << tok::r_paren;
+    SkipUntil(tok::r_paren, StopAtSemi);
+    return StmtError();
+  }
 
+  // Parse the goto label, if present.
+  unsigned NumLabels = 0;
+  if (AteExtraColon || Tok.is(tok::colon)) {
+    if (!AteExtraColon)
+      ConsumeToken();
+
+    while (true) {
+      if (Tok.isNot(tok::identifier)) {
+        Diag(Tok, diag::err_expected) << tok::identifier;
+        SkipUntil(tok::r_paren, StopAtSemi);
+        return StmtError();
+      }
+      LabelDecl *LD = Actions.LookupOrCreateLabel(Tok.getIdentifierInfo(),
+                                                  Tok.getLocation());
+      Names.push_back(Tok.getIdentifierInfo());
+      if (!LD) {
+        SkipUntil(tok::r_paren, StopAtSemi);
+        return StmtError();
+      }
+      ExprResult Res =
+          Actions.ActOnAddrLabel(Tok.getLocation(), Tok.getLocation(), LD);
+      Exprs.push_back(Res.get());
+      NumLabels++;
+      ConsumeToken();
+      if (!TryConsumeToken(tok::comma))
+        break;
+    }
+  } else if (isGotoAsm) {
+    Diag(Tok, diag::err_expected) << tok::colon;
+    SkipUntil(tok::r_paren, StopAtSemi);
+    return StmtError();
+  }
   T.consumeClose();
   return Actions.ActOnGCCAsmStmt(
       AsmLoc, false, isVolatile, NumOutputs, NumInputs, Names.data(),
-      Constraints, Exprs, AsmString.get(), Clobbers, T.getCloseLocation());
+      Constraints, Exprs, AsmString.get(), Clobbers, NumLabels,
+      T.getCloseLocation());
 }
 
 /// ParseAsmOperands - Parse the asm-operands production as used by

clang/lib/Sema/JumpDiagnostics.cpp

@@ -65,8 +65,10 @@ class JumpScopeChecker {
   llvm::DenseMap<Stmt*, unsigned> LabelAndGotoScopes;
   SmallVector<Stmt*, 16> Jumps;
 
-  SmallVector<IndirectGotoStmt*, 4> IndirectJumps;
+  SmallVector<Stmt*, 4> IndirectJumps;
+  SmallVector<Stmt*, 4> AsmJumps;
   SmallVector<LabelDecl*, 4> IndirectJumpTargets;
+  SmallVector<LabelDecl*, 4> AsmJumpTargets;
 public:
   JumpScopeChecker(Stmt *Body, Sema &S);
 private:
@@ -76,10 +78,10 @@ private:
   void BuildScopeInformation(Stmt *S, unsigned &origParentScope);
 
   void VerifyJumps();
-  void VerifyIndirectJumps();
+  void VerifyIndirectOrAsmJumps(bool IsAsmGoto);
   void NoteJumpIntoScopes(ArrayRef<unsigned> ToScopes);
-  void DiagnoseIndirectJump(IndirectGotoStmt *IG, unsigned IGScope,
+  void DiagnoseIndirectOrAsmJump(Stmt *IG, unsigned IGScope, LabelDecl *Target,
-                            LabelDecl *Target, unsigned TargetScope);
+                                 unsigned TargetScope);
   void CheckJump(Stmt *From, Stmt *To, SourceLocation DiagLoc,
                  unsigned JumpDiag, unsigned JumpDiagWarning,
                  unsigned JumpDiagCXX98Compat);
@@ -103,7 +105,8 @@ JumpScopeChecker::JumpScopeChecker(Stmt *Body, Sema &s)
 
   // Check that all jumps we saw are kosher.
   VerifyJumps();
-  VerifyIndirectJumps();
+  VerifyIndirectOrAsmJumps(false);
+  VerifyIndirectOrAsmJumps(true);
 }
 
 /// GetDeepestCommonScope - Finds the innermost scope enclosing the
@@ -316,7 +319,7 @@ void JumpScopeChecker::BuildScopeInformation(Stmt *S,
     }
 
     LabelAndGotoScopes[S] = ParentScope;
-    IndirectJumps.push_back(cast<IndirectGotoStmt>(S));
+    IndirectJumps.push_back(S);
     break;
 
   case Stmt::SwitchStmtClass:
@@ -339,6 +342,18 @@ void JumpScopeChecker::BuildScopeInformation(Stmt *S,
     Jumps.push_back(S);
     break;
 
+  case Stmt::GCCAsmStmtClass:
+    if (auto *GS = dyn_cast<GCCAsmStmt>(S))
+      if (GS->isAsmGoto()) {
+        // Remember both what scope a goto is in as well as the fact that we
+        // have it.  This makes the second scan not have to walk the AST again.
+        LabelAndGotoScopes[S] = ParentScope;
+        AsmJumps.push_back(GS);
+        for (auto *E : GS->labels())
+          AsmJumpTargets.push_back(E->getLabel());
+      }
+    break;
+
   case Stmt::IfStmtClass: {
     IfStmt *IS = cast<IfStmt>(S);
     if (!(IS->isConstexpr() || IS->isObjCAvailabilityCheck()))
@@ -629,14 +644,13 @@ void JumpScopeChecker::VerifyJumps() {
   }
 }
 
-/// VerifyIndirectJumps - Verify whether any possible indirect jump
+/// VerifyIndirectOrAsmJumps - Verify whether any possible indirect goto or
-/// might cross a protection boundary.  Unlike direct jumps, indirect
+/// asm goto jump might cross a protection boundary.  Unlike direct jumps,
-/// jumps count cleanups as protection boundaries:  since there's no
+/// indirect or asm goto jumps count cleanups as protection boundaries:
-/// way to know where the jump is going, we can't implicitly run the
+/// since there's no way to know where the jump is going, we can't implicitly
-/// right cleanups the way we can with direct jumps.
+/// run the right cleanups the way we can with direct jumps.
-///
+/// Thus, an indirect/asm jump is "trivial" if it bypasses no
-/// Thus, an indirect jump is "trivial" if it bypasses no
+/// initializations and no teardowns.  More formally, an indirect/asm jump
-/// initializations and no teardowns.  More formally, an indirect jump
 /// from A to B is trivial if the path out from A to DCA(A,B) is
 /// trivial and the path in from DCA(A,B) to B is trivial, where
 /// DCA(A,B) is the deepest common ancestor of A and B.
@@ -648,36 +662,41 @@ void JumpScopeChecker::VerifyJumps() {
 /// Under these definitions, this function checks that the indirect
 /// jump between A and B is trivial for every indirect goto statement A
 /// and every label B whose address was taken in the function.
-void JumpScopeChecker::VerifyIndirectJumps() {
+void JumpScopeChecker::VerifyIndirectOrAsmJumps(bool IsAsmGoto) {
-  if (IndirectJumps.empty()) return;
+  SmallVector<Stmt*, 4> GotoJumps = IsAsmGoto ? AsmJumps : IndirectJumps;
-
+  if (GotoJumps.empty())
+    return;
+  SmallVector<LabelDecl *, 4> JumpTargets =
+      IsAsmGoto ? AsmJumpTargets : IndirectJumpTargets;
   // If there aren't any address-of-label expressions in this function,
   // complain about the first indirect goto.
-  if (IndirectJumpTargets.empty()) {
+  if (JumpTargets.empty()) {
-    S.Diag(IndirectJumps[0]->getGotoLoc(),
+    assert(!IsAsmGoto &&"only indirect goto can get here");
+    S.Diag(GotoJumps[0]->getBeginLoc(),
            diag::err_indirect_goto_without_addrlabel);
     return;
   }
-
   // Collect a single representative of every scope containing an
-  // indirect goto.  For most code bases, this substantially cuts
+  // indirect or asm goto.  For most code bases, this substantially cuts
   // down on the number of jump sites we'll have to consider later.
-  typedef std::pair<unsigned, IndirectGotoStmt*> JumpScope;
+  typedef std::pair<unsigned, Stmt*> JumpScope;
   SmallVector<JumpScope, 32> JumpScopes;
   {
-    llvm::DenseMap<unsigned, IndirectGotoStmt*> JumpScopesMap;
+    llvm::DenseMap<unsigned, Stmt*> JumpScopesMap;
-    for (SmallVectorImpl<IndirectGotoStmt*>::iterator
+    for (SmallVectorImpl<Stmt *>::iterator I = GotoJumps.begin(),
-           I = IndirectJumps.begin(), E = IndirectJumps.end(); I != E; ++I) {
+                                           E = GotoJumps.end();
-      IndirectGotoStmt *IG = *I;
+         I != E; ++I) {
+      Stmt *IG = *I;
       if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(IG)))
         continue;
       unsigned IGScope = LabelAndGotoScopes[IG];
-      IndirectGotoStmt *&Entry = JumpScopesMap[IGScope];
+      Stmt *&Entry = JumpScopesMap[IGScope];
       if (!Entry) Entry = IG;
     }
     JumpScopes.reserve(JumpScopesMap.size());
-    for (llvm::DenseMap<unsigned, IndirectGotoStmt*>::iterator
+    for (llvm::DenseMap<unsigned, Stmt *>::iterator I = JumpScopesMap.begin(),
-           I = JumpScopesMap.begin(), E = JumpScopesMap.end(); I != E; ++I)
+                                                    E = JumpScopesMap.end();
+         I != E; ++I)
       JumpScopes.push_back(*I);
   }
 
@@ -685,8 +704,8 @@ void JumpScopeChecker::VerifyIndirectJumps() {
   // label whose address was taken somewhere in the function.
   // For most code bases, there will be only one such scope.
   llvm::DenseMap<unsigned, LabelDecl*> TargetScopes;
-  for (SmallVectorImpl<LabelDecl*>::iterator
+  for (SmallVectorImpl<LabelDecl *>::iterator I = JumpTargets.begin(),
-         I = IndirectJumpTargets.begin(), E = IndirectJumpTargets.end();
+                                              E = JumpTargets.end();
        I != E; ++I) {
     LabelDecl *TheLabel = *I;
     if (CHECK_PERMISSIVE(!LabelAndGotoScopes.count(TheLabel->getStmt())))
@@ -763,7 +782,7 @@ void JumpScopeChecker::VerifyIndirectJumps() {
       // Only diagnose if we didn't find something.
       if (IsReachable) continue;
 
-      DiagnoseIndirectJump(I->second, I->first, TargetLabel, TargetScope);
+      DiagnoseIndirectOrAsmJump(I->second, I->first, TargetLabel, TargetScope);
     }
   }
 }
@@ -784,12 +803,15 @@ static bool IsCXX98CompatWarning(Sema &S, unsigned InDiagNote) {
 }
 
 /// Produce primary diagnostic for an indirect jump statement.
-static void DiagnoseIndirectJumpStmt(Sema &S, IndirectGotoStmt *Jump,
+static void DiagnoseIndirectOrAsmJumpStmt(Sema &S, Stmt *Jump,
-                                     LabelDecl *Target, bool &Diagnosed) {
+                                          LabelDecl *Target, bool &Diagnosed) {
   if (Diagnosed)
     return;
-  S.Diag(Jump->getGotoLoc(), diag::err_indirect_goto_in_protected_scope);
+  bool IsAsmGoto = isa<GCCAsmStmt>(Jump);
-  S.Diag(Target->getStmt()->getIdentLoc(), diag::note_indirect_goto_target);
+  S.Diag(Jump->getBeginLoc(), diag::err_indirect_goto_in_protected_scope)
+      << IsAsmGoto;
+  S.Diag(Target->getStmt()->getIdentLoc(), diag::note_indirect_goto_target)
+      << IsAsmGoto;
   Diagnosed = true;
 }
 
@@ -803,10 +825,9 @@ void JumpScopeChecker::NoteJumpIntoScopes(ArrayRef<unsigned> ToScopes) {
 }
 
 /// Diagnose an indirect jump which is known to cross scopes.
-void JumpScopeChecker::DiagnoseIndirectJump(IndirectGotoStmt *Jump,
+void JumpScopeChecker::DiagnoseIndirectOrAsmJump(Stmt *Jump, unsigned JumpScope,
-                                            unsigned JumpScope,
+                                                 LabelDecl *Target,
-                                            LabelDecl *Target,
+                                                 unsigned TargetScope) {
-                                            unsigned TargetScope) {
   if (CHECK_PERMISSIVE(JumpScope == TargetScope))
     return;
 
@@ -816,7 +837,7 @@ void JumpScopeChecker::DiagnoseIndirectJump(IndirectGotoStmt *Jump,
   // Walk out the scope chain until we reach the common ancestor.
   for (unsigned I = JumpScope; I != Common; I = Scopes[I].ParentScope)
     if (Scopes[I].OutDiag) {
-      DiagnoseIndirectJumpStmt(S, Jump, Target, Diagnosed);
+      DiagnoseIndirectOrAsmJumpStmt(S, Jump, Target, Diagnosed);
       S.Diag(Scopes[I].Loc, Scopes[I].OutDiag);
     }
 
@@ -827,15 +848,18 @@ void JumpScopeChecker::DiagnoseIndirectJump(IndirectGotoStmt *Jump,
     if (IsCXX98CompatWarning(S, Scopes[I].InDiag))
       ToScopesCXX98Compat.push_back(I);
     else if (Scopes[I].InDiag) {
-      DiagnoseIndirectJumpStmt(S, Jump, Target, Diagnosed);
+      DiagnoseIndirectOrAsmJumpStmt(S, Jump, Target, Diagnosed);
       S.Diag(Scopes[I].Loc, Scopes[I].InDiag);
     }
 
   // Diagnose this jump if it would be ill-formed in C++98.
   if (!Diagnosed && !ToScopesCXX98Compat.empty()) {
-    S.Diag(Jump->getGotoLoc(),
+    bool IsAsmGoto = isa<GCCAsmStmt>(Jump);
-           diag::warn_cxx98_compat_indirect_goto_in_protected_scope);
+    S.Diag(Jump->getBeginLoc(),
-    S.Diag(Target->getStmt()->getIdentLoc(), diag::note_indirect_goto_target);
+           diag::warn_cxx98_compat_indirect_goto_in_protected_scope)
+        << IsAsmGoto;
+    S.Diag(Target->getStmt()->getIdentLoc(), diag::note_indirect_goto_target)
+        << IsAsmGoto;
     NoteJumpIntoScopes(ToScopesCXX98Compat);
   }
 }

clang/lib/Sema/SemaStmtAsm.cpp

@@ -209,11 +209,12 @@ static StringRef extractRegisterName(const Expr *Expression,
 static SourceLocation
 getClobberConflictLocation(MultiExprArg Exprs, StringLiteral **Constraints,
                            StringLiteral **Clobbers, int NumClobbers,
+                           unsigned NumLabels,
                            const TargetInfo &Target, ASTContext &Cont) {
   llvm::StringSet<> InOutVars;
   // Collect all the input and output registers from the extended asm
   // statement in order to check for conflicts with the clobber list
-  for (unsigned int i = 0; i < Exprs.size(); ++i) {
+  for (unsigned int i = 0; i < Exprs.size() - NumLabels; ++i) {
     StringRef Constraint = Constraints[i]->getString();
     StringRef InOutReg = Target.getConstraintRegister(
         Constraint, extractRegisterName(Exprs[i], Target));
@@ -241,6 +242,7 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
                                  unsigned NumInputs, IdentifierInfo **Names,
                                  MultiExprArg constraints, MultiExprArg Exprs,
                                  Expr *asmString, MultiExprArg clobbers,
+                                 unsigned NumLabels,
                                  SourceLocation RParenLoc) {
   unsigned NumClobbers = clobbers.size();
   StringLiteral **Constraints =
@@ -269,7 +271,7 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
       return new (Context)
           GCCAsmStmt(Context, AsmLoc, IsSimple, IsVolatile, NumOutputs,
                      NumInputs, Names, Constraints, Exprs.data(), AsmString,
-                     NumClobbers, Clobbers, RParenLoc);
+                     NumClobbers, Clobbers, NumLabels, RParenLoc);
     }
 
     ExprResult ER = CheckPlaceholderExpr(Exprs[i]);
@@ -330,7 +332,7 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
       return new (Context)
           GCCAsmStmt(Context, AsmLoc, IsSimple, IsVolatile, NumOutputs,
                      NumInputs, Names, Constraints, Exprs.data(), AsmString,
-                     NumClobbers, Clobbers, RParenLoc);
+                     NumClobbers, Clobbers, NumLabels, RParenLoc);
     }
   }
 
@@ -352,7 +354,7 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
       return new (Context)
           GCCAsmStmt(Context, AsmLoc, IsSimple, IsVolatile, NumOutputs,
                      NumInputs, Names, Constraints, Exprs.data(), AsmString,
-                     NumClobbers, Clobbers, RParenLoc);
+                     NumClobbers, Clobbers, NumLabels, RParenLoc);
     }
 
     ExprResult ER = CheckPlaceholderExpr(Exprs[i]);
@@ -451,14 +453,15 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
       return new (Context)
           GCCAsmStmt(Context, AsmLoc, IsSimple, IsVolatile, NumOutputs,
                      NumInputs, Names, Constraints, Exprs.data(), AsmString,
-                     NumClobbers, Clobbers, RParenLoc);
+                     NumClobbers, Clobbers, NumLabels, RParenLoc);
     }
   }
 
   GCCAsmStmt *NS =
     new (Context) GCCAsmStmt(Context, AsmLoc, IsSimple, IsVolatile, NumOutputs,
                              NumInputs, Names, Constraints, Exprs.data(),
-                             AsmString, NumClobbers, Clobbers, RParenLoc);
+                             AsmString, NumClobbers, Clobbers, NumLabels,
+                             RParenLoc);
   // Validate the asm string, ensuring it makes sense given the operands we
   // have.
   SmallVector<GCCAsmStmt::AsmStringPiece, 8> Pieces;
@@ -476,8 +479,10 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
 
     // Look for the correct constraint index.
     unsigned ConstraintIdx = Piece.getOperandNo();
+    // Labels are the last in the Exprs list.
+    if (NS->isAsmGoto() && ConstraintIdx >= NS->getNumInputs())
+      continue;
     unsigned NumOperands = NS->getNumOutputs() + NS->getNumInputs();
-
     // Look for the (ConstraintIdx - NumOperands + 1)th constraint with
     // modifier '+'.
     if (ConstraintIdx >= NumOperands) {
@@ -660,10 +665,39 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
   // Check for conflicts between clobber list and input or output lists
   SourceLocation ConstraintLoc =
       getClobberConflictLocation(Exprs, Constraints, Clobbers, NumClobbers,
+                                 NumLabels,
                                  Context.getTargetInfo(), Context);
   if (ConstraintLoc.isValid())
     targetDiag(ConstraintLoc, diag::error_inoutput_conflict_with_clobber);
 
+  // Check for duplicate asm operand name between input, output and label lists.
+  typedef std::pair<StringRef , Expr *> NamedOperand;
+  SmallVector<NamedOperand, 4> NamedOperandList;
+  for (unsigned i = 0, e = NumOutputs + NumInputs + NumLabels; i != e; ++i)
+    if (Names[i])
+      NamedOperandList.emplace_back(
+          std::make_pair(Names[i]->getName(), Exprs[i]));
+  // Sort NamedOperandList.
+  std::stable_sort(NamedOperandList.begin(), NamedOperandList.end(),
+              [](const NamedOperand &LHS, const NamedOperand &RHS) {
+                return LHS.first < RHS.first;
+              });
+  // Find adjacent duplicate operand.
+  SmallVector<NamedOperand, 4>::iterator Found =
+      std::adjacent_find(begin(NamedOperandList), end(NamedOperandList),
+                         [](const NamedOperand &LHS, const NamedOperand &RHS) {
+                           return LHS.first == RHS.first;
+                         });
+  if (Found != NamedOperandList.end()) {
+    Diag((Found + 1)->second->getBeginLoc(),
+         diag::error_duplicate_asm_operand_name)
+        << (Found + 1)->first;
+    Diag(Found->second->getBeginLoc(), diag::note_duplicate_asm_operand_name)
+        << Found->first;
+    return StmtError();
+  }
+  if (NS->isAsmGoto())
+    setFunctionHasBranchIntoScope();
   return NS;
 }
 

clang/lib/Sema/TreeTransform.h

@@ -1373,10 +1373,11 @@ public:
                                unsigned NumInputs, IdentifierInfo **Names,
                                MultiExprArg Constraints, MultiExprArg Exprs,
                                Expr *AsmString, MultiExprArg Clobbers,
+                               unsigned NumLabels,
                                SourceLocation RParenLoc) {
     return getSema().ActOnGCCAsmStmt(AsmLoc, IsSimple, IsVolatile, NumOutputs,
                                      NumInputs, Names, Constraints, Exprs,
-                                     AsmString, Clobbers, RParenLoc);
+                                     AsmString, Clobbers, NumLabels, RParenLoc);
   }
 
   /// Build a new MS style inline asm statement.
@@ -7051,6 +7052,16 @@ TreeTransform<Derived>::TransformGCCAsmStmt(GCCAsmStmt *S) {
     Exprs.push_back(Result.get());
   }
 
+  // Go through the Labels.
+  for (unsigned I = 0, E = S->getNumLabels(); I != E; ++I) {
+    Names.push_back(S->getLabelIdentifier(I));
+
+    ExprResult Result = getDerived().TransformExpr(S->getLabelExpr(I));
+    if (Result.isInvalid())
+      return StmtError();
+    ExprsChanged |= Result.get() != S->getLabelExpr(I);
+    Exprs.push_back(Result.get());
+  }
   if (!getDerived().AlwaysRebuild() && !ExprsChanged)
     return S;
 
@@ -7064,7 +7075,8 @@ TreeTransform<Derived>::TransformGCCAsmStmt(GCCAsmStmt *S) {
                                         S->isVolatile(), S->getNumOutputs(),
                                         S->getNumInputs(), Names.data(),
                                         Constraints, Exprs, AsmString.get(),
-                                        Clobbers, S->getRParenLoc());
+                                        Clobbers, S->getNumLabels(),
+                                        S->getRParenLoc());
 }
 
 template<typename Derived>

clang/lib/Serialization/ASTReaderStmt.cpp

@@ -370,12 +370,14 @@ void ASTStmtReader::VisitAsmStmt(AsmStmt *S) {
 
 void ASTStmtReader::VisitGCCAsmStmt(GCCAsmStmt *S) {
   VisitAsmStmt(S);
+  S->NumLabels = Record.readInt();
   S->setRParenLoc(ReadSourceLocation());
   S->setAsmString(cast_or_null<StringLiteral>(Record.readSubStmt()));
 
   unsigned NumOutputs = S->getNumOutputs();
   unsigned NumInputs = S->getNumInputs();
   unsigned NumClobbers = S->getNumClobbers();
+  unsigned NumLabels = S->getNumLabels();
 
   // Outputs and inputs
   SmallVector<IdentifierInfo *, 16> Names;
@@ -392,9 +394,14 @@ void ASTStmtReader::VisitGCCAsmStmt(GCCAsmStmt *S) {
   for (unsigned I = 0; I != NumClobbers; ++I)
     Clobbers.push_back(cast_or_null<StringLiteral>(Record.readSubStmt()));
 
+  // Labels
+  for (unsigned I = 0, N = NumLabels; I != N; ++I)
+    Exprs.push_back(Record.readSubStmt());
+
   S->setOutputsAndInputsAndClobbers(Record.getContext(),
                                     Names.data(), Constraints.data(),
                                     Exprs.data(), NumOutputs, NumInputs,
+                                    NumLabels,
                                     Clobbers.data(), NumClobbers);
 }
 

clang/lib/Serialization/ASTWriterStmt.cpp

@@ -283,6 +283,7 @@ void ASTStmtWriter::VisitAsmStmt(AsmStmt *S) {
 
 void ASTStmtWriter::VisitGCCAsmStmt(GCCAsmStmt *S) {
   VisitAsmStmt(S);
+  Record.push_back(S->getNumLabels());
   Record.AddSourceLocation(S->getRParenLoc());
   Record.AddStmt(S->getAsmString());
 
@@ -304,6 +305,9 @@ void ASTStmtWriter::VisitGCCAsmStmt(GCCAsmStmt *S) {
   for (unsigned I = 0, N = S->getNumClobbers(); I != N; ++I)
     Record.AddStmt(S->getClobberStringLiteral(I));
 
+  // Labels
+  for (auto *E : S->labels()) Record.AddStmt(E);
+
   Code = serialization::STMT_GCCASM;
 }
 

clang/test/Analysis/asm-goto.cpp

@@ -0,0 +1,52 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpCFG %s 2>&1 | FileCheck %s
+
+int foo(int cond)
+{
+label_true:
+  asm goto("testl %0, %0; jne %l1;" :: "r"(cond)::label_true, loop);
+  return 0;
+loop:
+  return 0;
+}
+
+// CHECK-LABEL: loop
+// CHECK-NEXT: 0
+// CHECK-NEXT: return
+// CHECK-NEXT: Preds (1): B3
+// CHECK-NEXT: Succs (1): B0
+
+// CHECK-LABEL: label_true
+// CHECK-NEXT: asm goto
+// CHECK-NEXT: Preds (2): B3 B4
+// CHECK-NEXT: Succs (3): B2 B3 B1
+
+
+int bar(int cond)
+{
+  asm goto("testl %0, %0; jne %l1;" :: "r"(cond)::L1, L2);
+  return 0;
+L1:
+L2:
+  return 0;
+}
+
+// CHECK: [B4]
+// CHECK-NEXT: asm goto
+// CHECK-NEXT: Preds (1): B5
+// CHECK-NEXT: Succs (3): B3 B2 B1
+
+int zoo(int n)
+{
+A5:
+A1:
+  asm goto("testl %0, %0; jne %l1;" :: "r"(n)::A1, A2, A3, A4, A5);
+A2:
+A3:
+A4:
+  return 0;
+}
+
+// CHECK-LABEL: A1
+// CHECK-NEXT: asm goto
+// CHECK-NEXT: Preds (2): B5 B4
+// CHECK-NEXT: Succs (5): B3 B4 B2 B1 B5

clang/test/CodeGen/asm-goto.c

@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -O0 -emit-llvm  %s -o - | FileCheck %s
+
+int foo(int cond)
+{
+  // CHECK: callbr void asm sideeffect
+  // CHECK: to label %asm.fallthrough [label %label_true, label %loop], !srcloc !2
+  // CHECK: asm.fallthrough:
+  asm volatile goto("testl %0, %0; jne %l1;" :: "r"(cond)::label_true, loop);
+  asm volatile goto("testl %0, %0; jne %l1;" :: "r"(cond)::label_true, loop);
+  // CHECK: callbr void asm sideeffect
+  // CHECK: to label %asm.fallthrough1 [label %label_true, label %loop], !srcloc !3
+  // CHECK: asm.fallthrough1:
+  return 0;
+loop:
+  return 0;
+label_true:
+  return 1;
+}

clang/test/CodeGen/asm.c

@@ -262,3 +262,15 @@ void t31(int len) {
   // CHECK: @t31
   // CHECK: call void asm sideeffect "", "=*%rm,=*rm,0,1,~{dirflag},~{fpsr},~{flags}"
 }
+
+// CHECK: @t32
+int t32(int cond)
+{
+  asm goto("testl %0, %0; jne %l1;" :: "r"(cond)::label_true, loop);
+  // CHECK: callbr void asm sideeffect "testl $0, $0; jne ${1:l};", "r,X,X,~{dirflag},~{fpsr},~{flags}"(i32 %0, i8* blockaddress(@t32, %label_true), i8* blockaddress(@t32, %loop)) #1
+  return 0;
+loop:
+  return 0;
+label_true:
+  return 1;
+}

clang/test/CodeGen/inline-asm-mixed-style.c

@@ -1,4 +1,3 @@
-// RUN: %clang_cc1 -triple i386-unknown-unknown -fasm-blocks -fsyntax-only -verify %s -DCHECK_ASM_GOTO
 // RUN: %clang_cc1 -triple i386-unknown-unknown -fasm-blocks -O0 -emit-llvm -S %s -o - | FileCheck %s
 // REQUIRES: x86-registered-target
 
@@ -20,10 +19,11 @@ void f() {
   // CHECK: movl    %ebx, %eax
   // CHECK: movl    %ecx, %edx
 
-#ifdef CHECK_ASM_GOTO
+  __asm volatile goto ("movl %ecx, %edx");
-  __asm volatile goto ("movl %ecx, %edx"); // expected-error {{'asm goto' constructs are not supported yet}}
+  // CHECK: movl    %ecx, %edx
 
   __asm mov eax, ebx
-  __asm goto ("movl %ecx, %edx"); // expected-error {{'asm goto' constructs are not supported yet}}
+  __asm goto ("movl %ecx, %edx");
-#endif
+  // CHECK: movl    %ebx, %eax
+  // CHECK: movl    %ecx, %edx
 }

clang/test/Coverage/c-language-features.inc

@@ -71,7 +71,9 @@ theif:
   }
 
   asm ("nop");
-
+  int cond;
+  asm goto("testl %0, %0; jne %l1;" :: "r"(cond)::label_true);
+label_true:
   return;
 }
 

clang/test/PCH/asm.h

@@ -1,10 +1,14 @@
 // Header for the PCH test asm.c
 
 void f() {
-  int i;
+  int i,cond;
 
   asm ("foo\n" : : "a" (i + 2));
   asm ("foo\n" : [symbolic_name] "=a" (i) : "[symbolic_name]" (i));
+  asm volatile goto("testl %0, %0; jne %l1;" :: "r"(cond)::label_true, loop);
+label_true:
+loop:
+  return;
 }
 
 void clobbers() {

clang/test/Parser/asm.c

@@ -21,6 +21,56 @@ void f2() {
 }
 
 
+int a, b, c, d, e, f, g, h, i, j, k, l;
+
+void
+fgoto1 (void)
+{
+  __asm__ volatile goto (""
+            :: [a] "r" (a), [b] "r" (b), [c] "r" (c), [d] "r" (d),
+               [e] "r" (e), [f] "r" (f), [g] "r" (g), [h] "r" (h),
+               [i] "r" (i), [j] "r" (j), [k] "r" (k), [l] "r" (l)
+            ::lab1,lab2);
+lab1: return;
+lab2: return;
+}
+
+void
+fgoto2 (void)
+{
+  __asm__ volatile goto (""
+            :: [a] "r,m" (a), [b] "r,m" (b), [c] "r,m" (c), [d] "r,m" (d),
+               [e] "r,m" (e), [f] "r,m" (f), [g] "r,m" (g), [h] "r,m" (h),
+               [i] "r,m" (i), [j] "r,m" (j), [k] "r,m" (k), [l] "r,m" (l)
+            :: lab);
+  lab: return;
+}
+
+int zoo ()
+{
+  int x,cond,*e;
+  // expected-error@+1 {{expected ')'}}
+  asm ("mov %[e], %[e]" : : [e] "rm" (*e)::a)
+  // expected-error@+1 {{'asm goto' cannot have output constraints}}
+  asm goto ("decl %0; jnz %l[a]" :"=r"(x): "m"(x) : "memory" : a);
+  // expected-error@+1 {{expected identifie}}
+  asm goto ("decl %0;" :: "m"(x) : "memory" : );
+  // expected-error@+1 {{expected ':'}}
+  asm goto ("decl %0;" :: "m"(x) : "memory" );
+  // expected-error@+1 {{use of undeclared label 'x'}}
+  asm goto ("decl %0;" :: "m"(x) : "memory" :x);
+  // expected-error@+1 {{use of undeclared label 'b'}}
+  asm goto ("decl %0;" :: "m"(x) : "memory" :b);
+  // expected-error@+1 {{invalid operand number in inline asm string}}
+  asm goto ("testl %0, %0; jne %l3;" :: "r"(cond)::label_true, loop);
+  // expected-error@+1 {{unknown symbolic operand name in inline assembly string}}
+  asm goto ("decl %0; jnz %l[b]" :: "m"(x) : "memory" : a);
+a:
+label_true:
+loop:
+  return 0;
+}
+
 // rdar://5952468
 __asm ; // expected-error {{expected '(' after 'asm'}}
 

clang/test/Parser/asm.cpp

@@ -7,3 +7,54 @@ int foo4 asm (u"bar4"); // expected-error {{cannot use unicode string literal in
 int foo5 asm (U"bar5"); // expected-error {{cannot use unicode string literal in 'asm'}}
 int foo6 asm ("bar6"_x); // expected-error {{string literal with user-defined suffix cannot be used here}}
 int foo6 asm ("" L"bar7"); // expected-error {{cannot use wide string literal in 'asm'}}
+
+int zoo ()
+{
+  int x,cond,*e;
+  // expected-error@+1 {{expected ')'}}
+  asm ("mov %[e], %[e]" : : [e] "rm" (*e)::a)
+  // expected-error@+1  {{'asm goto' cannot have output constraints}}
+  asm goto ("decl %0; jnz %l[a]" :"=r"(x): "m"(x) : "memory" : a);
+  // expected-error@+1 {{expected identifie}}
+  asm goto ("decl %0;" :: "m"(x) : "memory" : );
+  // expected-error@+1  {{expected ':'}}
+  asm goto ("decl %0;" :: "m"(x) : "memory" );
+  // expected-error@+1 {{use of undeclared label 'x'}}
+  asm goto ("decl %0;" :: "m"(x) : "memory" :x);
+  // expected-error@+1 {{use of undeclared label 'b'}}
+  asm goto ("decl %0;" :: "m"(x) : "memory" :b);
+  // expected-error@+1 {{invalid operand number in inline asm string}}
+  asm goto ("testl %0, %0; jne %l3;" :: "r"(cond)::label_true, loop);
+  // expected-error@+1 {{unknown symbolic operand name in inline assembly string}}
+  asm goto ("decl %0; jnz %l[b]" :: "m"(x) : "memory" : a);
+label_true:
+loop:
+a:
+  return 0;
+}
+
+
+int a, b, c, d, e, f, g, h, i, j, k, l;
+
+void
+fgoto1 (void)
+{
+  __asm__ volatile goto (""
+            :: [a] "r" (a), [b] "r" (b), [c] "r" (c), [d] "r" (d),
+               [e] "r" (e), [f] "r" (f), [g] "r" (g), [h] "r" (h),
+               [i] "r" (i), [j] "r" (j), [k] "r" (k), [l] "r" (l)
+            ::lab1,lab2);
+lab1: return;
+lab2: return;
+}
+
+void
+fgoto2 (void)
+{
+  __asm__ volatile goto (""
+            :: [a] "r,m" (a), [b] "r,m" (b), [c] "r,m" (c), [d] "r,m" (d),
+               [e] "r,m" (e), [f] "r,m" (f), [g] "r,m" (g), [h] "r,m" (h),
+               [i] "r,m" (i), [j] "r,m" (j), [k] "r,m" (k), [l] "r,m" (l)
+            :: lab);
+  lab: return;
+}

clang/test/Sema/asm-goto.cpp

@@ -0,0 +1,45 @@
+// RUN: %clang_cc1 %s -triple i386-pc-linux-gnu -verify -fsyntax-only
+
+struct NonTrivial {
+  ~NonTrivial();
+  int f(int);
+private:
+  int k;
+};
+void JumpDiagnostics(int n) {
+// expected-error@+1 {{cannot jump from this goto statement to its label}}
+  goto DirectJump;
+// expected-note@+1 {{jump bypasses variable with a non-trivial destructor}}
+  NonTrivial tnp1;
+
+DirectJump:
+// expected-error@+1 {{cannot jump from this asm goto statement to one of its possible targets}}
+  asm goto("jmp %l0;" ::::Later);
+// expected-note@+1 {{jump bypasses variable with a non-trivial destructor}}
+  NonTrivial tnp2;
+// expected-note@+1 {{possible target of asm goto statement}}
+Later:
+  return;
+}
+
+struct S { ~S(); };
+void foo(int a) {
+  if (a) {
+FOO:
+// expected-note@+2 {{jump exits scope of variable with non-trivial destructor}}
+// expected-note@+1 {{jump exits scope of variable with non-trivial destructor}}
+    S s;
+    void *p = &&BAR;
+// expected-error@+1 {{cannot jump from this asm goto statement to one of its possible targets}}
+  asm goto("jmp %l0;" ::::BAR);
+// expected-error@+1 {{cannot jump from this indirect goto statement to one of its possible targets}}
+    goto *p;
+    p = &&FOO;
+    goto *p;
+    return;
+  }
+// expected-note@+2 {{possible target of asm goto statement}}
+// expected-note@+1 {{possible target of indirect goto statement}}
+BAR:
+  return;
+}

clang/test/Sema/asm.c

@@ -295,3 +295,24 @@ int test17(int t0)
   return r0 + r1;
 }
 
+void test18()
+{
+  // expected-error@+2 {{duplicate use of asm operand name "lab"}}
+  // expected-note@+1 {{asm operand name "lab" first referenced here}}
+  asm goto ("" : : : : lab, lab, lab2, lab);
+  // expected-error@+2 {{duplicate use of asm operand name "lab"}}
+  // expected-note@+1 {{asm operand name "lab" first referenced here}}
+  asm goto ("xorw %[lab], %[lab]; je %l[lab]" : : [lab] "i" (0) : : lab);
+lab:;
+lab2:;
+  int x,x1;
+  // expected-error@+2 {{duplicate use of asm operand name "lab"}}
+  // expected-note@+1 {{asm operand name "lab" first referenced here}}
+  asm ("" : [lab] "=r" (x),[lab] "+r" (x) : [lab1] "r" (x));
+  // expected-error@+2 {{duplicate use of asm operand name "lab"}}
+  // expected-note@+1 {{asm operand name "lab" first referenced here}}
+  asm ("" : [lab] "=r" (x1) : [lab] "r" (x));
+  // expected-error@+1 {{invalid operand number in inline asm string}}
+  asm ("jne %l0":::);
+  asm goto ("jne %l0"::::lab);
+}

clang/test/Sema/inline-asm-validate-tmpl.cpp

@@ -23,3 +23,13 @@ template <int N> void	testc(int value)
 	asm("rol %1, %0" :"=r"(value): "I"(N + 1));
 }
 int	foo() { testc<2>(10); }
+
+// these should compile without error
+template <int N> bool testd()
+{
+  __asm goto ("" : : : : lab);
+  return true;
+lab:
+  return false;
+}
+bool foox() { return testd<0> (); }

clang/test/Sema/scope-check.c

@@ -232,3 +232,19 @@ void test15(int n, void *pc) {
 
 // rdar://9024687
 int test16(int [sizeof &&z]); // expected-error {{use of address-of-label extension outside of a function body}}
+
+//Asm goto:
+int test16(int n)
+{
+  // expected-error@+2 {{cannot jump from this asm goto statement to one of its possible targets}}
+  // expected-error@+1 {{cannot jump from this asm goto statement to one of its possible targets}}
+  asm volatile goto("testl %0, %0; jne %l1;" :: "r"(n)::label_true, loop);
+  // expected-note@+2 {{jump bypasses initialization of variable length array}}
+  // expected-note@+1 {{possible target of asm goto statement}}
+  return ({int a[n];label_true: 2;});
+  // expected-note@+1 {{jump bypasses initialization of variable length array}}
+  int b[n];
+// expected-note@+1 {{possible target of asm goto statement}}
+loop:
+  return 0;
+}