Index: docs/LangRef.rst
===================================================================
--- docs/LangRef.rst
+++ docs/LangRef.rst
@@ -4308,6 +4308,7 @@
 
 ``DISubrange`` nodes are the elements for ``DW_TAG_array_type`` variants of
 :ref:`DICompositeType`. ``count: -1`` indicates an empty array.
+``count: !3`` describes the count with a :ref:`DIExpression`.
 ``count: !9`` describes the count with a :ref:`DILocalVariable`.
 ``count: !11`` describes the count with a :ref:`DIGlobalVariable`.
 
@@ -4317,19 +4318,22 @@
     !1 = !DISubrange(count: 5, lowerBound: 1) ; array counting from 1
     !2 = !DISubrange(count: -1) ; empty array.
 
-    ; Scopes used in rest of example
+    !3 = !DIExpression(DW_OP_constu, 42)
+    !4 = !DISubrange(count !3, lowerBound: 1) ; array counting from 1 to 43
+
+    ; Scopes
     !6 = !DIFile(filename: "vla.c", directory: "/path/to/file")
     !7 = distinct !DICompileUnit(language: DW_LANG_C99, ...
     !8 = distinct !DISubprogram(name: "foo", scope: !7, file: !6, line: 5, ...
 
     ; Use of local variable as count value
-    !9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
-    !10 = !DILocalVariable(name: "count", scope: !8, file: !6, line: 42, type: !9)
-    !11 = !DISubrange(count !10, lowerBound: 0)
+    !8 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+    !9 = !DILocalVariable(name: "count", scope: !8, file: !6, line: 42, type: !8)
+    !10 = !DISubrange(count !9, lowerBound: 0)
 
     ; Use of global variable as count value
-    !12 = !DIGlobalVariable(name: "count", scope: !8, file: !6, line: 22, type: !9)
-    !13 = !DISubrange(count !12, lowerBound: 0)
+    !11 = !DIGlobalVariable(name: "count", scope: !8, file: !6, line: 22, type: !8)
+    !12 = !DISubrange(count !11, lowerBound: 0)
 
 .. _DIEnumerator:
 
Index: include/llvm/IR/DebugInfoMetadata.h
===================================================================
--- include/llvm/IR/DebugInfoMetadata.h
+++ include/llvm/IR/DebugInfoMetadata.h
@@ -379,6 +379,10 @@
     return dyn_cast<DIVariable>(getRawCountNode());
   }
 
+  DIExpression *getCountExpression() const {
+    return dyn_cast<DIExpression>(getRawCountNode());
+  }
+
   static bool classof(const Metadata *MD) {
     return MD->getMetadataID() == DISubrangeKind;
   }
Index: lib/CodeGen/AsmPrinter/DwarfUnit.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1311,7 +1311,13 @@
   if (DefaultLowerBound == -1 || LowerBound != DefaultLowerBound)
     addUInt(DW_Subrange, dwarf::DW_AT_lower_bound, None, LowerBound);
 
-  if (auto *CV = SR->getCountVariable()) {
+  if (auto *Expr = SR->getCountExpression()) {
+    DIELoc *Loc = new (DIEValueAllocator) DIELoc;
+    DIEDwarfExpression DExpr(*Asm, *this, *Loc);
+    DExpr.addExpression(Expr);
+    DExpr.finalize();
+    addBlock(DW_Subrange, dwarf::DW_AT_count, Loc);
+  } else if (auto *CV = SR->getCountVariable()) {
     // I think we can assert() here that the DIE of the count variable has
     // already been instantiated, since 'finishVariableDefinition' that
     // creates the types for a variable is always called _after_ the DIEs
Index: lib/IR/AsmWriter.cpp
===================================================================
--- lib/IR/AsmWriter.cpp
+++ lib/IR/AsmWriter.cpp
@@ -1628,7 +1628,7 @@
   if (auto *CE = N->getCount())
     Printer.printInt("count", CE->getSExtValue(), /* ShouldSkipZero */ false);
   else
-    Printer.printMetadata("count", N->getCountVariable(),
+    Printer.printMetadata("count", N->getRawCountNode(),
                           /*ShouldSkipNull */ false);
   Printer.printInt("lowerBound", N->getLowerBound());
   Out << ")";
Index: lib/IR/Verifier.cpp
===================================================================
--- lib/IR/Verifier.cpp
+++ lib/IR/Verifier.cpp
@@ -860,8 +860,9 @@
   AssertDI(N.getTag() == dwarf::DW_TAG_subrange_type, "invalid tag", &N);
   auto *CI = N.getCount();
   AssertDI(!CI || CI->getSExtValue() >= -1, "invalid subrange count", &N);
-  AssertDI(CI || N.getCountVariable(),
-      "Count must either be a signed constant or a DIVariable",
+  AssertDI(
+      CI || N.getCountVariable() || N.getCountExpression(),
+      "Count must either be a signed constant, a DIVariable or a DIExpression",
       &N);
 }
 
Index: test/Assembler/debug-info.ll
===================================================================
--- test/Assembler/debug-info.ll
+++ test/Assembler/debug-info.ll
@@ -1,8 +1,8 @@
 ; RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis | FileCheck %s
 ; RUN: verify-uselistorder %s
 
-; CHECK: !named = !{!0, !0, !1, !2, !3, !4, !5, !6, !7, !8, !8, !9, !10, !11, !12, !13, !14, !15, !16, !17, !18, !19, !20, !21, !22, !23, !24, !25, !26, !27, !27, !28, !29, !30, !31, !32, !33, !33}
-!named = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9, !10, !11, !12, !13, !14, !15, !16, !17, !18, !19, !20, !21, !22, !23, !24, !25, !26, !27, !28, !29, !30, !31, !32, !33, !34, !35, !36, !37}
+; CHECK: !named = !{!0, !0, !1, !2, !3, !4, !5, !6, !7, !8, !8, !9, !10, !11, !12, !13, !14, !15, !16, !17, !18, !19, !20, !21, !22, !23, !24, !25, !26, !27, !27, !28, !29, !30, !31, !32, !33, !33, !34, !34, !35}
+!named = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9, !10, !11, !12, !13, !14, !15, !16, !17, !18, !19, !20, !21, !22, !23, !24, !25, !26, !27, !28, !29, !30, !31, !32, !33, !34, !35, !36, !37, !39, !41, !43}
 
 ; CHECK:      !0 = !DISubrange(count: 3)
 ; CHECK-NEXT: !1 = !DISubrange(count: 3, lowerBound: 4)
@@ -85,3 +85,12 @@
 !35 = !DIFile(filename: "file", directory: "dir", checksumkind: CSK_MD5, checksum: "000102030405060708090a0b0c0d0e0f")
 !36 = !DIFile(filename: "file", directory: "dir", checksumkind: CSK_None)
 !37 = !DIFile(filename: "file", directory: "dir", checksumkind: CSK_None, checksum: "")
+
+; CHECK-NEXT: !34 = !DISubrange(count: !DIExpression(DW_OP_constu, 42), lowerBound: 4)
+; CHECK-NEXT: !35 = !DISubrange(count: !DIExpression(DW_OP_constu, 1))
+!38 = !DIExpression(DW_OP_constu, 42)
+!39 = !DISubrange(count: !38, lowerBound: 4)
+!40 = !DIExpression(DW_OP_constu, 42)
+!41 = !DISubrange(count: !40, lowerBound: 4)
+!42 = !DIExpression(DW_OP_constu, 1)
+!43 = !DISubrange(count: !42, lowerBound: 0)
Index: test/Bitcode/disubrange.ll
===================================================================
--- test/Bitcode/disubrange.ll
+++ test/Bitcode/disubrange.ll
@@ -1,5 +1,6 @@
 ; Check that the DISubrange 'count' reference is correctly uniqued and restored,
-; since it can take the value of either a signed integer or a DIVariable.
+; since it can take the value of either a signed integer, a DIExpression
+; or a DIVariable.
 ; RUN: llvm-as < %s | llvm-dis | FileCheck %s
 
 define void @foo(i32 %n) {
@@ -34,12 +35,13 @@
 !18 = !DILocation(line: 21, column: 7, scope: !7)
 !19 = !DILocalVariable(name: "vla", scope: !7, file: !1, line: 21, type: !20)
 !20 = !DICompositeType(tag: DW_TAG_array_type, baseType: !10, align: 32, elements: !21)
-!21 = !{!22, !23, !24, !25, !26, !27}
+!21 = !{!22, !23, !24, !25, !26, !27, !28}
 
 ; CHECK-DAG: ![[NODE:[0-9]+]] = !DILocalVariable(name: "vla_expr"
 ; CHECK-DAG: ![[RANGE:[0-9]+]] = !DISubrange(count: ![[NODE]])
 ; CHECK-DAG: ![[CONST:[0-9]+]] = !DISubrange(count: 16)
-; CHECK-DAG: ![[MULTI:[0-9]+]] = !{![[RANGE]], ![[RANGE]], ![[CONST]], ![[CONST]], ![[CONST]], ![[CONST]]}
+; CHECK-DAG: ![[EXPR:[0-9]+]] = !DISubrange(count: !DIExpression(DW_OP_constu, 16))
+; CHECK-DAG: ![[MULTI:[0-9]+]] = !{![[RANGE]], ![[RANGE]], ![[CONST]], ![[CONST]], ![[CONST]], ![[CONST]], ![[EXPR]]}
 ; CHECK-DAG: elements: ![[MULTI]]
 !22 = !DISubrange(count: !16)
 !23 = !DISubrange(count: !16)
@@ -47,3 +49,4 @@
 !25 = !DISubrange(count: i16 16)
 !26 = !DISubrange(count: i32 16)
 !27 = !DISubrange(count: i64 16)
+!28 = !DISubrange(count: !DIExpression(DW_OP_constu, 16))
\ No newline at end of file
Index: test/DebugInfo/Generic/disubrange.ll
===================================================================
--- test/DebugInfo/Generic/disubrange.ll
+++ test/DebugInfo/Generic/disubrange.ll
@@ -4,6 +4,8 @@
 ; CHECK-DAG: DW_AT_count [DW_FORM_ref4]  (cu + {{.*}} => {[[NODE:[0-9a-zA-Zx]+]]})
 ; CHECK-DAG: [[NODE]]: DW_TAG_variable [4]
 
+; CHECK: DW_AT_count [DW_FORM_exprloc] (<0x2> 10 2a )
+
 define void @foo(i32 %n) !dbg !7 {
 entry:
   call void @llvm.dbg.value(metadata i32 %n, i64 0, metadata !12, metadata !19), !dbg !20
@@ -33,8 +35,10 @@
 !14 = !DIBasicType(name: "long unsigned int", size: 64, encoding: DW_ATE_unsigned)
 !15 = !DILocalVariable(name: "vla", scope: !7, file: !1, line: 21, type: !16)
 !16 = !DICompositeType(tag: DW_TAG_array_type, baseType: !10, align: 32, elements: !17)
-!17 = !{!18, !18}
+!17 = !{!18, !22}
 !18 = !DISubrange(count: !13)
 !19 = !DIExpression()
 !20 = !DILocation(line: 20, column: 14, scope: !7)
 !21 = !DILocation(line: 22, column: 1, scope: !7)
+!22 = !DISubrange(count: !23)
+!23 = !DIExpression(DW_OP_constu, 42)
Index: test/Verifier/invalid-disubrange-count-node.ll
===================================================================
--- test/Verifier/invalid-disubrange-count-node.ll
+++ test/Verifier/invalid-disubrange-count-node.ll
@@ -33,5 +33,5 @@
 !19 = !DILocalVariable(name: "vla", scope: !7, file: !1, line: 21, type: !20)
 !20 = !DICompositeType(tag: DW_TAG_array_type, baseType: !10, align: 32, elements: !21)
 !21 = !{!22}
-; CHECK: Count must either be a signed constant or a DIVariable
+; CHECK: Count must either be a signed constant, a DIVariable or a DIExpression
 !22 = !DISubrange(count: !17)
Index: unittests/IR/MetadataTest.cpp
===================================================================
--- unittests/IR/MetadataTest.cpp
+++ unittests/IR/MetadataTest.cpp
@@ -943,6 +943,18 @@
   EXPECT_EQ(N, MDNode::replaceWithUniqued(std::move(Temp)));
 }
 
+TEST_F(DISubrangeTest, getCountExpression) {
+  uint64_t Elements[] = { dwarf::DW_OP_constu, 5 };
+  auto *N = DISubrange::get(Context, DIExpression::get(Context, Elements), 7);
+  EXPECT_EQ(dwarf::DW_TAG_subrange_type, N->getTag());
+  EXPECT_NE(nullptr, N->getCountExpression());
+  EXPECT_EQ(nullptr, N->getCount());
+  EXPECT_EQ(7, N->getLowerBound());
+
+  TempDISubrange Temp = N->clone();
+  EXPECT_EQ(N, MDNode::replaceWithUniqued(std::move(Temp)));
+}
+
 TEST_F(DISubrangeTest, getEmptyArray) {
   auto *N = DISubrange::get(Context, -1, 0);
   EXPECT_EQ(dwarf::DW_TAG_subrange_type, N->getTag());