Index: lib/Target/ARM/ARMAsmPrinter.cpp
===================================================================
--- lib/Target/ARM/ARMAsmPrinter.cpp
+++ lib/Target/ARM/ARMAsmPrinter.cpp
@@ -629,6 +629,8 @@
   MCTargetStreamer &TS = *OutStreamer.getTargetStreamer();
   ARMTargetStreamer &ATS = static_cast<ARMTargetStreamer &>(TS);
 
+  ATS.emitTextAttribute(ARMBuildAttrs::conformance, "2.09");
+
   ATS.switchVendor("aeabi");
 
   std::string CPUString = Subtarget->getCPUString();
Index: lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
===================================================================
--- lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
+++ lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
@@ -300,7 +300,19 @@
     StringRef StringValue;
 
     static bool LessTag(const AttributeItem &LHS, const AttributeItem &RHS) {
-      return (LHS.Tag < RHS.Tag);
+      // The conformance tag must be emitted first when serialised
+      // into an object file. Specifically, the addenda to the ARM ABI
+      // states that (2.3.7.4):
+      //
+      // "To simplify recognition by consumers in the common case of
+      // claiming conformity for the whole file, this tag should be
+      // emitted first in a file-scope sub-subsection of the first
+      // public subsection of the attributes section."
+      //
+      // So it is special-cased in this comparison predicate when the
+      // attributes are sorted in finishAttributeSection().
+      return (RHS.Tag != ARMBuildAttrs::conformance) &&
+             ((LHS.Tag == ARMBuildAttrs::conformance) || (LHS.Tag < RHS.Tag));
     }
   };
 
Index: test/CodeGen/ARM/build-attributes.ll
===================================================================
--- test/CodeGen/ARM/build-attributes.ll
+++ test/CodeGen/ARM/build-attributes.ll
@@ -285,6 +285,7 @@
 ; V8: .eabi_attribute 21, 1
 ; V8-NOT: .eabi_attribute 22
 ; V8: .eabi_attribute 23, 3
+; V8: .eabi_attribute 67, "2.09"
 
 ; V8-FAST-NOT:   .eabi_attribute 19
 ;; The default does have an FPU, and for V8-A, it flushes preserving sign.
Index: test/MC/ARM/directive-eabi_attribute.s
===================================================================
--- test/MC/ARM/directive-eabi_attribute.s
+++ test/MC/ARM/directive-eabi_attribute.s
@@ -5,6 +5,14 @@
         .syntax unified
         .thumb
 
+        .eabi_attribute Tag_conformance, "2.09"
+@ CHECK: .eabi_attribute 67, "2.09"
+@ Tag_conformance should be be emitted first in a file-scope
+@ sub-subsection of the first public subsection of the attributes
+@ section. 2.3.7.4 of ABI Addenda.
+@ CHECK-OBJ:        Tag: 67
+@ CHECK-OBJ-NEXT:   TagName: conformance
+@ CHECK-OBJ-NEXT:   Value: 2.09
 	.eabi_attribute Tag_CPU_raw_name, "Cortex-A9"
 @ CHECK: .eabi_attribute 4, "Cortex-A9"
 @ CHECK-OBJ:        Tag: 4
@@ -220,11 +228,6 @@
 @ CHECK-OBJ-NEXT:   Value: 0
 @ CHECK-OBJ-NEXT:   TagName: T2EE_use
 @ CHECK-OBJ-NEXT:   Description: Not Permitted
-	.eabi_attribute Tag_conformance, "2.09"
-@ CHECK: .eabi_attribute 67, "2.09"
-@ CHECK-OBJ:        Tag: 67
-@ CHECK-OBJ-NEXT:   TagName: conformance
-@ CHECK-OBJ-NEXT:   Value: 2.09
 	.eabi_attribute Tag_Virtualization_use, 0
 @ CHECK: .eabi_attribute 68, 0
 @ CHECK-OBJ:        Tag: 68
Index: test/tools/llvm-readobj/ARM/attribute-conformance-1.s
===================================================================
--- /dev/null
+++ test/tools/llvm-readobj/ARM/attribute-conformance-1.s
@@ -0,0 +1,8 @@
+@ RUN: llvm-mc -triple armv7-elf -filetype asm -o - %s | FileCheck %s
+@ RUN: llvm-mc -triple armv7-eabi -filetype obj -o - %s \
+@ RUN:   | llvm-readobj -arm-attributes - | FileCheck %s --check-prefix=CHECK-OBJ
+.eabi_attribute  Tag_conformance, "0"
+@CHECK:   .eabi_attribute 67, "0"
+@CHECK-OBJ: Tag: 67
+@CHECK-OBJ-NEXT: TagName: conformance
+@CHECK-OBJ-NEXT: Value: 0
Index: test/tools/llvm-readobj/ARM/attribute-conformance-2.s
===================================================================
--- /dev/null
+++ test/tools/llvm-readobj/ARM/attribute-conformance-2.s
@@ -0,0 +1,8 @@
+@ RUN: llvm-mc -triple armv7-elf -filetype asm -o - %s | FileCheck %s
+@ RUN: llvm-mc -triple armv7-eabi -filetype obj -o - %s \
+@ RUN:   | llvm-readobj -arm-attributes - | FileCheck %s --check-prefix=CHECK-OBJ
+.eabi_attribute  Tag_conformance, "A.long--non numeric oddity...!!"
+@CHECK:   .eabi_attribute 67, "A.long--non numeric oddity...!!"
+@CHECK-OBJ: Tag: 67
+@CHECK-OBJ-NEXT: TagName: conformance
+@CHECK-OBJ-NEXT: Value: A.long--non numeric oddity...!!