Index: lib/Target/ARM/ARMAsmPrinter.cpp
===================================================================
--- lib/Target/ARM/ARMAsmPrinter.cpp
+++ lib/Target/ARM/ARMAsmPrinter.cpp
@@ -904,16 +904,16 @@
         ATS.emitAttribute(ARMBuildAttrs::ABI_PCS_wchar_t, WCharWidth);
       }
 
-      // ABI_enum_size to indicate enum width
-      // FIXME: There is no way to emit value 0 (enums prohibited) or value 3
-      //        (all enums contain a value needing 32 bits to encode).
-      if (auto EnumWidthValue = mdconst::extract_or_null<ConstantInt>(
-              SourceModule->getModuleFlag("min_enum_size"))) {
-        int EnumWidth = EnumWidthValue->getZExtValue();
-        assert((EnumWidth == 1 || EnumWidth == 4) &&
-               "Minimum enum width must be 1 or 4 bytes");
-        int EnumBuildAttr = EnumWidth == 1 ? 1 : 2;
-        ATS.emitAttribute(ARMBuildAttrs::ABI_enum_size, EnumBuildAttr);
+      // Generate the correct Tag_ABI_enum_size build attribute.
+      if (auto BuildAttrValue = mdconst::extract_or_null<ConstantInt>(
+              SourceModule->getModuleFlag("enumsize_buildattr"))) {
+        int EnumSizeBuildAttr = BuildAttrValue->getZExtValue();
+        assert((EnumSizeBuildAttr == ARMBuildAttrs::EnumProhibited ||
+                EnumSizeBuildAttr == ARMBuildAttrs::EnumSmallest ||
+                EnumSizeBuildAttr == ARMBuildAttrs::Enum32Bit ||
+                EnumSizeBuildAttr == ARMBuildAttrs::Enum32BitABI) &&
+               "Unsupported build attribute");
+        ATS.emitAttribute(ARMBuildAttrs::ABI_enum_size, EnumSizeBuildAttr);
       }
     }
   }
Index: test/CodeGen/ARM/2016-08-24-ARM-LDST-dbginfo-bug.ll
===================================================================
--- test/CodeGen/ARM/2016-08-24-ARM-LDST-dbginfo-bug.ll
+++ test/CodeGen/ARM/2016-08-24-ARM-LDST-dbginfo-bug.ll
@@ -37,7 +37,7 @@
 !3 = !{i32 2, !"Dwarf Version", i32 4}
 !4 = !{i32 2, !"Debug Info Version", i32 3}
 !5 = !{i32 1, !"wchar_size", i32 4}
-!6 = !{i32 1, !"min_enum_size", i32 4}
+!6 = !{i32 1, !"enumsize_buildattr", i32 2}
 !7 = !{!"clang version 4.0.0 "}
 !8 = distinct !DISubprogram(name: "s_idx", scope: !1, file: !1, line: 6, type: !9, isLocal: false, isDefinition: true, scopeLine: 7, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !16)
 !9 = !DISubroutineType(types: !10)
Index: test/CodeGen/ARM/arm-shrink-wrapping-linux.ll
===================================================================
--- test/CodeGen/ARM/arm-shrink-wrapping-linux.ll
+++ test/CodeGen/ARM/arm-shrink-wrapping-linux.ll
@@ -136,7 +136,7 @@
 !llvm.module.flags = !{!0, !1}
 
 !0 = !{i32 1, !"wchar_size", i32 4}
-!1 = !{i32 1, !"min_enum_size", i32 4}
+!1 = !{i32 1, !"enumsize_buildattr", i32 2}
 !2 = !{!3, !3, i64 0}
 !3 = !{!"omnipotent char", !4, i64 0}
 !4 = !{!"Simple C/C++ TBAA"}
Index: test/CodeGen/ARM/constantpool-promote-dbg.ll
===================================================================
--- test/CodeGen/ARM/constantpool-promote-dbg.ll
+++ test/CodeGen/ARM/constantpool-promote-dbg.ll
@@ -31,7 +31,7 @@
 !3 = !{i32 2, !"Dwarf Version", i32 4}
 !4 = !{i32 2, !"Debug Info Version", i32 3}
 !5 = !{i32 1, !"wchar_size", i32 4}
-!6 = !{i32 1, !"min_enum_size", i32 4}
+!6 = !{i32 1, !"enumsize_buildattr", i32 2}
 !7 = !{!"clang version 3.9.0 (http://llvm.org/git/clang.git 075a2bc2570dfcbb6d6aed6c836e4c62b37afea6)"}
 !8 = distinct !DISubprogram(name: "fn1", scope: !1, file: !1, line: 1, type: !9, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: true, unit: !0, variables: !2)
 !9 = !DISubroutineType(types: !10)
Index: test/CodeGen/ARM/constantpool-promote.ll
===================================================================
--- test/CodeGen/ARM/constantpool-promote.ll
+++ test/CodeGen/ARM/constantpool-promote.ll
@@ -147,5 +147,5 @@
 !llvm.ident = !{!2}
 
 !0 = !{i32 1, !"wchar_size", i32 4}
-!1 = !{i32 1, !"min_enum_size", i32 4}
+!1 = !{i32 1, !"enumsize_buildattr", i32 2}
 !2 = !{!"Apple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn)"}
Index: test/CodeGen/ARM/metadata-abi-enums.ll
===================================================================
--- /dev/null
+++ test/CodeGen/ARM/metadata-abi-enums.ll
@@ -0,0 +1,14 @@
+; RUN: llc < %s | FileCheck %s
+
+target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-n32-S64"
+target triple = "armv7--none-eabi"
+
+define i32 @f(i64 %z) {
+	ret i32 0
+}
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 1, !"enumsize_buildattr", i32 3}
+
+; CHECK: .eabi_attribute 26, 3   @ Tag_ABI_enum_size
Index: test/CodeGen/ARM/metadata-default.ll
===================================================================
--- test/CodeGen/ARM/metadata-default.ll
+++ test/CodeGen/ARM/metadata-default.ll
@@ -10,7 +10,7 @@
 !llvm.module.flags = !{!0, !1}
 
 !0 = !{i32 1, !"wchar_size", i32 4}
-!1 = !{i32 1, !"min_enum_size", i32 4}
+!1 = !{i32 1, !"enumsize_buildattr", i32 2}
 
 ; CHECK: .eabi_attribute 18, 4   @ Tag_ABI_PCS_wchar_t
 ; CHECK: .eabi_attribute 26, 2   @ Tag_ABI_enum_size
Index: test/CodeGen/ARM/metadata-no-enums.ll
===================================================================
--- /dev/null
+++ test/CodeGen/ARM/metadata-no-enums.ll
@@ -0,0 +1,14 @@
+; RUN: llc < %s | FileCheck %s
+
+target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-n32-S64"
+target triple = "armv7--none-eabi"
+
+define i32 @f(i64 %z) {
+	ret i32 0
+}
+
+!llvm.module.flags = !{!0}
+
+!0 = !{i32 1, !"enumsize_buildattr", i32 0}
+
+; CHECK: .eabi_attribute 26, 0   @ Tag_ABI_enum_size
Index: test/CodeGen/ARM/metadata-short-enums.ll
===================================================================
--- test/CodeGen/ARM/metadata-short-enums.ll
+++ test/CodeGen/ARM/metadata-short-enums.ll
@@ -10,7 +10,7 @@
 !llvm.module.flags = !{!0, !1}
 
 !0 = !{i32 1, !"wchar_size", i32 4}
-!1 = !{i32 1, !"min_enum_size", i32 1}
+!1 = !{i32 1, !"enumsize_buildattr", i32 1}
 
 ; CHECK: .eabi_attribute 18, 4   @ Tag_ABI_PCS_wchar_t
 ; CHECK: .eabi_attribute 26, 1   @ Tag_ABI_enum_size
Index: test/CodeGen/ARM/metadata-short-wchar.ll
===================================================================
--- test/CodeGen/ARM/metadata-short-wchar.ll
+++ test/CodeGen/ARM/metadata-short-wchar.ll
@@ -10,7 +10,7 @@
 !llvm.module.flags = !{!0, !1}
 
 !0 = !{i32 1, !"wchar_size", i32 2}
-!1 = !{i32 1, !"min_enum_size", i32 4}
+!1 = !{i32 1, !"enumsize_buildattr", i32 2}
 
 ; CHECK: .eabi_attribute 18, 2   @ Tag_ABI_PCS_wchar_t
 ; CHECK: .eabi_attribute 26, 2   @ Tag_ABI_enum_size
Index: test/CodeGen/MIR/ARM/sched-it-debug-nodes.mir
===================================================================
--- test/CodeGen/MIR/ARM/sched-it-debug-nodes.mir
+++ test/CodeGen/MIR/ARM/sched-it-debug-nodes.mir
@@ -74,7 +74,7 @@
   !22 = !{i32 2, !"Dwarf Version", i32 4}
   !23 = !{i32 2, !"Debug Info Version", i32 3}
   !24 = !{i32 1, !"wchar_size", i32 4}
-  !25 = !{i32 1, !"min_enum_size", i32 4}
+  !25 = !{i32 1, !"enumsize_buildattr", i32 2}
   !26 = !{!"clang version 3.7.0  (llvm/trunk 237059)"}
   !27 = !DIExpression()
   !28 = !DILocation(line: 9, scope: !4)
Index: test/DebugInfo/ARM/PR26163.ll
===================================================================
--- test/DebugInfo/ARM/PR26163.ll
+++ test/DebugInfo/ARM/PR26163.ll
@@ -94,7 +94,7 @@
 !21 = !DIDerivedType(tag: DW_TAG_member, name: "tv_usec", scope: !17, file: !5, line: 4, baseType: !8, size: 32, align: 32, offset: 64)
 !22 = !{i32 2, !"Debug Info Version", i32 3}
 !23 = !{i32 1, !"wchar_size", i32 4}
-!24 = !{i32 1, !"min_enum_size", i32 4}
+!24 = !{i32 1, !"enumsize_buildattr", i32 2}
 !25 = !{!"clang version 3.9.0 (https://github.com/llvm-mirror/clang 89dda3855cda574f355e6defa1d77bdae5053994) (llvm/trunk 257891)"}
 !26 = !DIExpression()
 !27 = !DILocation(line: 11, scope: !11, inlinedAt: !28)
Index: test/DebugInfo/ARM/big-endian-dump.ll
===================================================================
--- test/DebugInfo/ARM/big-endian-dump.ll
+++ test/DebugInfo/ARM/big-endian-dump.ll
@@ -14,5 +14,5 @@
 !3 = !{i32 2, !"Dwarf Version", i32 4}
 !4 = !{i32 2, !"Debug Info Version", i32 1}
 !5 = !{i32 1, !"wchar_size", i32 4}
-!6 = !{i32 1, !"min_enum_size", i32 4}
+!6 = !{i32 1, !"enumsize_buildattr", i32 2}
 !7 = !{!"clang version 3.6.0 "}
Index: test/DebugInfo/ARM/little-endian-dump.ll
===================================================================
--- test/DebugInfo/ARM/little-endian-dump.ll
+++ test/DebugInfo/ARM/little-endian-dump.ll
@@ -14,5 +14,5 @@
 !3 = !{i32 2, !"Dwarf Version", i32 4}
 !4 = !{i32 2, !"Debug Info Version", i32 1}
 !5 = !{i32 1, !"wchar_size", i32 4}
-!6 = !{i32 1, !"min_enum_size", i32 4}
+!6 = !{i32 1, !"enumsize_buildattr", i32 2}
 !7 = !{!"clang version 3.6.0 "}
Index: test/DebugInfo/ARM/multiple-constant-uses-drops-dbgloc.ll
===================================================================
--- test/DebugInfo/ARM/multiple-constant-uses-drops-dbgloc.ll
+++ test/DebugInfo/ARM/multiple-constant-uses-drops-dbgloc.ll
@@ -46,7 +46,7 @@
 !12 = !{i32 2, !"Dwarf Version", i32 4}
 !13 = !{i32 2, !"Debug Info Version", i32 3}
 !14 = !{i32 1, !"wchar_size", i32 4}
-!15 = !{i32 1, !"min_enum_size", i32 4}
+!15 = !{i32 1, !"enumsize_buildattr", i32 2}
 !16 = !{!"clang version 3.7.0 (http://llvm.org/git/clang.git 9b0abb9df531ef7928c8182120e1869affca17d5) (http://llvm.org/git/llvm.git b1e759524dd94f7ce1e24935daed8383927e96c1)"}
 !17 = !DILocation(line: 6, column: 8, scope: !4)
 !18 = !DILocation(line: 7, column: 7, scope: !4)