Index: include/llvm/CodeGen/AsmPrinter.h
===================================================================
--- include/llvm/CodeGen/AsmPrinter.h
+++ include/llvm/CodeGen/AsmPrinter.h
@@ -487,6 +487,8 @@
                             const MachineBasicBlock *MBB,
                             unsigned uid) const;
     void EmitLLVMUsedList(const ConstantArray *InitList);
+    /// Emit llvm.ident metadata in an '.ident' directive.
+    void EmitModuleIdents(Module &M);
     void EmitXXStructorList(const Constant *List, bool isCtor);
     GCMetadataPrinter *GetOrCreateGCPrinter(GCStrategy *C);
   };
Index: lib/CodeGen/AsmPrinter/AsmPrinter.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -953,6 +953,9 @@
     if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
       MP->finishAssembly(*this);
 
+  // Emit llvm.ident metadata in an '.ident' directive.
+  EmitModuleIdents(M);
+
   // If we don't have any trampolines, then we don't require stack memory
   // to be executable. Some targets have a directive to declare this.
   Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
@@ -1332,6 +1335,21 @@
   }
 }
 
+void AsmPrinter::EmitModuleIdents(Module &M) {
+  if (!MAI->hasIdentDirective())
+    return;
+
+  if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
+    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
+      const MDNode *N = NMD->getOperand(i);
+      assert(N->getNumOperands() == 1 && 
+             "llvm.ident metadata entry can have only one operand");
+      if (const MDString *S = cast<MDString>(N->getOperand(0)))
+          OutStreamer.EmitIdent(S->getString());
+    }
+  }
+}
+
 //===--------------------------------------------------------------------===//
 // Emission and print routines
 //
Index: lib/IR/Verifier.cpp
===================================================================
--- lib/IR/Verifier.cpp
+++ lib/IR/Verifier.cpp
@@ -216,6 +216,7 @@
         visitNamedMDNode(*I);
 
       visitModuleFlags(M);
+      visitModuleIdents(M);
 
       // Verify Debug Info.
       verifyDebugInfo(M);
@@ -260,6 +261,7 @@
     void visitGlobalAlias(GlobalAlias &GA);
     void visitNamedMDNode(NamedMDNode &NMD);
     void visitMDNode(MDNode &MD, Function *F);
+    void visitModuleIdents(Module &M);
     void visitModuleFlags(Module &M);
     void visitModuleFlag(MDNode *Op, DenseMap<MDString*, MDNode*> &SeenIDs,
                          SmallVectorImpl<MDNode*> &Requirements);
@@ -614,6 +616,23 @@
   }
 }
 
+void Verifier::visitModuleIdents(Module &M) {
+  const NamedMDNode *Idents = M.getNamedMetadata("llvm.ident");
+  if (!Idents) return;
+  
+  // llvm.ident takes a list of metadata entry. Each entry has only one string.
+  // Scan each llvm.ident entry and make sure that this requirement is met.
+  for (unsigned i = 0, e = Idents->getNumOperands(); i != e; ++i) {
+    const MDNode *N = Idents->getOperand(i);
+    Assert1(N->getNumOperands() == 1,
+            "incorrect number of operands in llvm.ident metadata", N);
+    Assert1(isa<MDString>(N->getOperand(0)),
+            ("invalid value for llvm.ident metadata entry operand"
+             "(the operand should be a string)"),
+            N->getOperand(0));
+  } 
+}
+
 void Verifier::visitModuleFlags(Module &M) {
   const NamedMDNode *Flags = M.getModuleFlagsMetadata();
   if (!Flags) return;
Index: test/CodeGen/X86/ident-metadata.ll
===================================================================
--- test/CodeGen/X86/ident-metadata.ll
+++ test/CodeGen/X86/ident-metadata.ll
@@ -0,0 +1,17 @@
+; RUN: llc -march=x86 < %s | FileCheck %s
+; RUN: llc -march=x86 -filetype=obj -o %t < %s
+; RUN: llvm-readobj -s -sd  %t | FileCheck %s -check-prefix=OBJ
+; Verify that llvm.ident metadata is emitted as .ident
+; directives in assembly files, and in the .comment section in ELF object files.
+
+; CHECK: .ident  "clang version x.x"
+; CHECK-NEXT: .ident  "something else"
+
+; OBJ: Name: .comment (7)
+; OBJ: SectionData (
+; OBJ-NEXT: 0000: 00636C61 6E672076 65727369 6F6E2078
+; OBJ-NEXT: 0010: 2E780073 6F6D6574 68696E67 20656C73
+; OBJ-NEXT: 0020: 6500
+!llvm.ident = !{!0, !1}
+!0 = metadata !{metadata !"clang version x.x"}
+!1 = metadata !{metadata !"something else"}
Index: test/Verifier/ident-meta1.ll
===================================================================
--- test/Verifier/ident-meta1.ll
+++ test/Verifier/ident-meta1.ll
@@ -0,0 +1,12 @@
+; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
+; Verify that llvm.ident is properly structured.
+; llvm.ident takes a list of metadata entries.
+; Each metadata entry can have only one string.
+
+!llvm.ident = !{!0, !1}
+!0 = metadata !{metadata !"version string"}
+!1 = metadata !{metadata !"string1", metadata !"string2"}
+; CHECK: assembly parsed, but does not verify as correct!
+; CHECK-NEXT: incorrect number of operands in llvm.ident metadata
+; CHECK-NEXT: metadata !1
+
Index: test/Verifier/ident-meta2.ll
===================================================================
--- test/Verifier/ident-meta2.ll
+++ test/Verifier/ident-meta2.ll
@@ -0,0 +1,13 @@
+; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
+; Verify that llvm.ident is properly structured.
+; llvm.ident takes a list of metadata entries.
+; Each metadata entry can contain one string only.
+
+!llvm.ident = !{!0, !1, !2, !3}
+!0 = metadata !{metadata !"str1"}
+!1 = metadata !{metadata !"str2"}
+!2 = metadata !{metadata !"str3"}
+!3 = metadata !{i32 1}
+; CHECK: assembly parsed, but does not verify as correct!
+; CHECK-NEXT: invalid value for llvm.ident metadata entry operand(the operand should be a string)
+; CHECK-NEXT: i32 1
Index: test/Verifier/ident-meta3.ll
===================================================================
--- test/Verifier/ident-meta3.ll
+++ test/Verifier/ident-meta3.ll
@@ -0,0 +1,10 @@
+; RUN: not llvm-as < %s -o /dev/null 2>&1 | FileCheck %s
+; Verify that llvm.ident is properly structured.
+; llvm.ident takes a list of metadata entries.
+; Each metadata entry can contain one string only.
+
+!llvm.ident = !{!0}
+!0 = metadata !{metadata !{metadata !"nested metadata"}}
+; CHECK: assembly parsed, but does not verify as correct!
+; CHECK-NEXT: invalid value for llvm.ident metadata entry operand(the operand should be a string)
+; CHECK-NEXT: metadata !1