diff --git a/lib/CodeGen/AsmPrinter/DwarfAccelTable.cpp b/lib/CodeGen/AsmPrinter/DwarfAccelTable.cpp
index 4a13cc260ad..09c47356adc 100644
--- a/lib/CodeGen/AsmPrinter/DwarfAccelTable.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfAccelTable.cpp
@@ -98,6 +98,15 @@ void DwarfAccelTable::FinalizeTable(AsmPrinter *Asm, StringRef Prefix) {
     Buckets[bucket].push_back(Data[i]);
     Data[i]->Sym = Asm->GetTempSymbol(Prefix, i);
   }
+
+  // Sort the contents of the buckets by hash value so that hash
+  // collisions end up together. Stable sort makes testing easier and
+  // doesn't cost much more.
+  for (size_t i = 0; i < Buckets.size(); ++i)
+    std::stable_sort(Buckets[i].begin(), Buckets[i].end(),
+                     [] (HashData *LHS, HashData *RHS) {
+                       return LHS->HashValue < RHS->HashValue;
+                     });
 }
 
 // Emits the header for the table via the AsmPrinter.
@@ -137,19 +146,32 @@ void DwarfAccelTable::EmitBuckets(AsmPrinter *Asm) {
       Asm->EmitInt32(index);
     else
       Asm->EmitInt32(UINT32_MAX);
-    index += Buckets[i].size();
+    // Buckets point in the list of hashes, not to the data. Do not
+    // increment the index multiple times in case of hash collisions.
+    uint64_t PrevHash = UINT64_MAX;
+    for (auto *HD : Buckets[i]) {
+      uint32_t HashValue = HD->HashValue;
+      if (PrevHash != HashValue)
+        ++index;
+      PrevHash = HashValue;
+    }
   }
 }
 
 // Walk through the buckets and emit the individual hashes for each
 // bucket.
 void DwarfAccelTable::EmitHashes(AsmPrinter *Asm) {
+  uint64_t PrevHash = UINT64_MAX;
   for (size_t i = 0, e = Buckets.size(); i < e; ++i) {
     for (HashList::const_iterator HI = Buckets[i].begin(),
                                   HE = Buckets[i].end();
          HI != HE; ++HI) {
+      uint32_t HashValue = (*HI)->HashValue;
+      if (PrevHash == HashValue)
+        continue;
       Asm->OutStreamer.AddComment("Hash in Bucket " + Twine(i));
-      Asm->EmitInt32((*HI)->HashValue);
+      Asm->EmitInt32(HashValue);
+      PrevHash = HashValue;
     }
   }
 }
@@ -159,10 +181,15 @@ void DwarfAccelTable::EmitHashes(AsmPrinter *Asm) {
 // beginning of the section. The non-section symbol will be output later
 // when we emit the actual data.
 void DwarfAccelTable::EmitOffsets(AsmPrinter *Asm, MCSymbol *SecBegin) {
+  uint64_t PrevHash = UINT64_MAX;
   for (size_t i = 0, e = Buckets.size(); i < e; ++i) {
     for (HashList::const_iterator HI = Buckets[i].begin(),
                                   HE = Buckets[i].end();
          HI != HE; ++HI) {
+      uint32_t HashValue = (*HI)->HashValue;
+      if (PrevHash == HashValue)
+        continue;
+      PrevHash = HashValue;
       Asm->OutStreamer.AddComment("Offset in Bucket " + Twine(i));
       MCContext &Context = Asm->OutStreamer.getContext();
       const MCExpr *Sub = MCBinaryExpr::CreateSub(
@@ -183,6 +210,10 @@ void DwarfAccelTable::EmitData(AsmPrinter *Asm, DwarfDebug *D,
     for (HashList::const_iterator HI = Buckets[i].begin(),
                                   HE = Buckets[i].end();
          HI != HE; ++HI) {
+      // Terminate the previous entry if there is no hash collision
+      // with the current one.
+      if (PrevHash != UINT64_MAX && PrevHash != (*HI)->HashValue)
+        Asm->EmitInt32(0);
       // Remember to emit the label for our offset.
       Asm->OutStreamer.EmitLabel((*HI)->Sym);
       Asm->OutStreamer.AddComment((*HI)->Str);
@@ -201,11 +232,10 @@ void DwarfAccelTable::EmitData(AsmPrinter *Asm, DwarfDebug *D,
           Asm->EmitInt8(HD->Flags);
         }
       }
-      // Emit a 0 to terminate the data unless we have a hash collision.
-      if (PrevHash != (*HI)->HashValue)
-        Asm->EmitInt32(0);
       PrevHash = (*HI)->HashValue;
     }
+    // Emit the final end marker for the bucket.
+    Asm->EmitInt32(0);
   }
 }
 
diff --git a/test/DebugInfo/accel-table-hash-collisions.ll b/test/DebugInfo/accel-table-hash-collisions.ll
new file mode 100644
index 00000000000..25bd2f426c8
--- /dev/null
+++ b/test/DebugInfo/accel-table-hash-collisions.ll
@@ -0,0 +1,92 @@
+; REQUIRES: object-emission
+; RUN: %llc_dwarf -dwarf-accel-tables=Enable -filetype=obj -o - < %s | llvm-dwarfdump -debug-dump=apple_names - | FileCheck %s
+
+; Generated from the following C code using
+; clang -S -emit-llvm hash-collision.c
+;
+; The names of the variables have been chosen so that they produce hash collisions.
+; There are 12 names here that are hashed to only 6 hashes (each pair of lines
+; hashes to the same value, see the CHECK lines below).
+;
+; int ForceTopDown;
+; int _ZNSt3__116allocator_traitsINS_9allocatorINS_11__tree_nodeINS_12__value_typeIPN4llvm10BasicBlockEPNS4_10RegionNodeEEEPvEEEEE11__constructIS9_JNS_4pairIS6_S8_EEEEEvNS_17integral_constantIbLb1EEERSC_PT_DpOT0_;
+; int _ZN5clang23DataRecursiveASTVisitorIN12_GLOBAL__N_124UnusedBackingIvarCheckerEE26TraverseCUDAKernelCallExprEPNS_18CUDAKernelCallExprE; 
+; int _ZN4llvm16DenseMapIteratorIPNS_10MDLocationENS_6detail13DenseSetEmptyENS_10MDNodeInfoIS1_EENS3_12DenseSetPairIS2_EELb0EE23AdvancePastEmptyBucketsEv;
+; int _ZNK4llvm12LivePhysRegs5printERNS_11raw_ostreamE;
+; int _ZN4llvm15ScalarEvolution14getSignedRangeEPKNS_4SCEVE;
+; int k1;
+; int is;
+; int setStmt;
+; int _ZN4llvm5TwineC1Ei;
+; int _ZNK5clang12OverrideAttr5cloneERNS_10ASTContextE;
+; int _ZN4llvm22MachineModuleInfoMachOD2Ev;
+
+; Check that we have the right amount of hashes.
+; CHECK: Bucket count = 6
+; CHECK: Hashes count = 6
+
+; Check that all the names are present in the output
+; CHECK:  Hash = 0x00597841
+; CHECK:    Name: {{[0-9a-f]*}} "is"
+; CHECK:    Name: {{[0-9a-f]*}} "k1"
+
+; CHECK: Hash = 0xa4b42a1e
+; CHECK:    Name: {{[0-9a-f]*}} "_ZN5clang23DataRecursiveASTVisitorIN12_GLOBAL__N_124UnusedBackingIvarCheckerEE26TraverseCUDAKernelCallExprEPNS_18CUDAKernelCallExprE"
+; CHECK:    Name: {{[0-9a-f]*}} "_ZN4llvm16DenseMapIteratorIPNS_10MDLocationENS_6detail13DenseSetEmptyENS_10MDNodeInfoIS1_EENS3_12DenseSetPairIS2_EELb0EE23AdvancePastEmptyBucketsEv"
+
+; CHECK: Hash = 0xeee7c0b2
+; CHECK:    Name: {{[0-9a-f]*}} "_ZNK4llvm12LivePhysRegs5printERNS_11raw_ostreamE"
+; CHECK:    Name: {{[0-9a-f]*}} "_ZN4llvm15ScalarEvolution14getSignedRangeEPKNS_4SCEVE"
+
+; CHECK: Hash = 0xea48ac5f
+; CHECK:    Name: {{[0-9a-f]*}} "ForceTopDown"
+; CHECK:    Name: {{[0-9a-f]*}} "_ZNSt3__116allocator_traitsINS_9allocatorINS_11__tree_nodeINS_12__value_typeIPN4llvm10BasicBlockEPNS4_10RegionNodeEEEPvEEEEE11__constructIS9_JNS_4pairIS6_S8_EEEEEvNS_17integral_constantIbLb1EEERSC_PT_DpOT0_"
+
+; CHECK:  Hash = 0x6b22f71f
+; CHECK:    Name: {{[0-9a-f]*}} "_ZNK5clang12OverrideAttr5cloneERNS_10ASTContextE"
+; CHECK:    Name: {{[0-9a-f]*}} "_ZN4llvm22MachineModuleInfoMachOD2Ev"
+
+; CHECK:  Hash = 0x8c248979
+; CHECK:    Name: {{[0-9a-f]*}} "setStmt"
+; CHECK:    Name: {{[0-9a-f]*}} "_ZN4llvm5TwineC1Ei"
+
+
+
+@ForceTopDown = common global i32 0, align 4
+@_ZNSt3__116allocator_traitsINS_9allocatorINS_11__tree_nodeINS_12__value_typeIPN4llvm10BasicBlockEPNS4_10RegionNodeEEEPvEEEEE11__constructIS9_JNS_4pairIS6_S8_EEEEEvNS_17integral_constantIbLb1EEERSC_PT_DpOT0_ = common global i32 0, align 4
+@_ZN5clang23DataRecursiveASTVisitorIN12_GLOBAL__N_124UnusedBackingIvarCheckerEE26TraverseCUDAKernelCallExprEPNS_18CUDAKernelCallExprE = common global i32 0, align 4
+@_ZN4llvm16DenseMapIteratorIPNS_10MDLocationENS_6detail13DenseSetEmptyENS_10MDNodeInfoIS1_EENS3_12DenseSetPairIS2_EELb0EE23AdvancePastEmptyBucketsEv = common global i32 0, align 4
+@_ZNK4llvm12LivePhysRegs5printERNS_11raw_ostreamE = common global i32 0, align 4
+@_ZN4llvm15ScalarEvolution14getSignedRangeEPKNS_4SCEVE = common global i32 0, align 4
+@k1 = common global i32 0, align 4
+@is = common global i32 0, align 4
+@setStmt = common global i32 0, align 4
+@_ZN4llvm5TwineC1Ei = common global i32 0, align 4
+@_ZNK5clang12OverrideAttr5cloneERNS_10ASTContextE = common global i32 0, align 4
+@_ZN4llvm22MachineModuleInfoMachOD2Ev = common global i32 0, align 4
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!17, !18, !19}
+!llvm.ident = !{!20}
+
+!0 = !MDCompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.7.0 (trunk 231548) (llvm/trunk 231547)", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2, retainedTypes: !2, subprograms: !2, globals: !3, imports: !2)
+!1 = !MDFile(filename: "hash-collisions.c", directory: "/tmp")
+!2 = !{}
+!3 = !{!4, !6, !7, !8, !9, !10, !11, !12, !13, !14, !15, !16}
+!4 = !MDGlobalVariable(name: "ForceTopDown", scope: !0, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, variable: i32* @ForceTopDown)
+!5 = !MDBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!6 = !MDGlobalVariable(name: "_ZNSt3__116allocator_traitsINS_9allocatorINS_11__tree_nodeINS_12__value_typeIPN4llvm10BasicBlockEPNS4_10RegionNodeEEEPvEEEEE11__constructIS9_JNS_4pairIS6_S8_EEEEEvNS_17integral_constantIbLb1EEERSC_PT_DpOT0_", scope: !0, file: !1, line: 2, type: !5, isLocal: false, isDefinition: true, variable: i32* @_ZNSt3__116allocator_traitsINS_9allocatorINS_11__tree_nodeINS_12__value_typeIPN4llvm10BasicBlockEPNS4_10RegionNodeEEEPvEEEEE11__constructIS9_JNS_4pairIS6_S8_EEEEEvNS_17integral_constantIbLb1EEERSC_PT_DpOT0_)
+!7 = !MDGlobalVariable(name: "_ZN5clang23DataRecursiveASTVisitorIN12_GLOBAL__N_124UnusedBackingIvarCheckerEE26TraverseCUDAKernelCallExprEPNS_18CUDAKernelCallExprE", scope: !0, file: !1, line: 3, type: !5, isLocal: false, isDefinition: true, variable: i32* @_ZN5clang23DataRecursiveASTVisitorIN12_GLOBAL__N_124UnusedBackingIvarCheckerEE26TraverseCUDAKernelCallExprEPNS_18CUDAKernelCallExprE)
+!8 = !MDGlobalVariable(name: "_ZN4llvm16DenseMapIteratorIPNS_10MDLocationENS_6detail13DenseSetEmptyENS_10MDNodeInfoIS1_EENS3_12DenseSetPairIS2_EELb0EE23AdvancePastEmptyBucketsEv", scope: !0, file: !1, line: 4, type: !5, isLocal: false, isDefinition: true, variable: i32* @_ZN4llvm16DenseMapIteratorIPNS_10MDLocationENS_6detail13DenseSetEmptyENS_10MDNodeInfoIS1_EENS3_12DenseSetPairIS2_EELb0EE23AdvancePastEmptyBucketsEv)
+!9 = !MDGlobalVariable(name: "_ZNK4llvm12LivePhysRegs5printERNS_11raw_ostreamE", scope: !0, file: !1, line: 5, type: !5, isLocal: false, isDefinition: true, variable: i32* @_ZNK4llvm12LivePhysRegs5printERNS_11raw_ostreamE)
+!10 = !MDGlobalVariable(name: "_ZN4llvm15ScalarEvolution14getSignedRangeEPKNS_4SCEVE", scope: !0, file: !1, line: 6, type: !5, isLocal: false, isDefinition: true, variable: i32* @_ZN4llvm15ScalarEvolution14getSignedRangeEPKNS_4SCEVE)
+!11 = !MDGlobalVariable(name: "k1", scope: !0, file: !1, line: 7, type: !5, isLocal: false, isDefinition: true, variable: i32* @k1)
+!12 = !MDGlobalVariable(name: "is", scope: !0, file: !1, line: 8, type: !5, isLocal: false, isDefinition: true, variable: i32* @is)
+!13 = !MDGlobalVariable(name: "setStmt", scope: !0, file: !1, line: 9, type: !5, isLocal: false, isDefinition: true, variable: i32* @setStmt)
+!14 = !MDGlobalVariable(name: "_ZN4llvm5TwineC1Ei", scope: !0, file: !1, line: 10, type: !5, isLocal: false, isDefinition: true, variable: i32* @_ZN4llvm5TwineC1Ei)
+!15 = !MDGlobalVariable(name: "_ZNK5clang12OverrideAttr5cloneERNS_10ASTContextE", scope: !0, file: !1, line: 11, type: !5, isLocal: false, isDefinition: true, variable: i32* @_ZNK5clang12OverrideAttr5cloneERNS_10ASTContextE)
+!16 = !MDGlobalVariable(name: "_ZN4llvm22MachineModuleInfoMachOD2Ev", scope: !0, file: !1, line: 12, type: !5, isLocal: false, isDefinition: true, variable: i32* @_ZN4llvm22MachineModuleInfoMachOD2Ev)
+!17 = !{i32 2, !"Dwarf Version", i32 2}
+!18 = !{i32 2, !"Debug Info Version", i32 3}
+!19 = !{i32 1, !"PIC Level", i32 2}
+!20 = !{!"clang version 3.7.0 (trunk 231548) (llvm/trunk 231547)"}