diff --git a/Android.mk b/Android.mk
index 8a507da..a6278af 100644
--- a/Android.mk
+++ b/Android.mk
@@ -95,6 +95,7 @@
 		source/opt/decompose_initialized_variables_pass.cpp \
 		source/opt/decoration_manager.cpp \
 		source/opt/def_use_manager.cpp \
+		source/opt/desc_sroa.cpp \
 		source/opt/dominator_analysis.cpp \
 		source/opt/dominator_tree.cpp \
 		source/opt/eliminate_dead_constant_pass.cpp \
diff --git a/BUILD.gn b/BUILD.gn
index 90d80e5..84b21e1 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -491,6 +491,8 @@
     "source/opt/decoration_manager.h",
     "source/opt/def_use_manager.cpp",
     "source/opt/def_use_manager.h",
+    "source/opt/desc_sroa.cpp",
+    "source/opt/desc_sroa.h",
     "source/opt/dominator_analysis.cpp",
     "source/opt/dominator_analysis.h",
     "source/opt/dominator_tree.cpp",
diff --git a/include/spirv-tools/optimizer.hpp b/include/spirv-tools/optimizer.hpp
index a52dcd0..d442b97 100644
--- a/include/spirv-tools/optimizer.hpp
+++ b/include/spirv-tools/optimizer.hpp
@@ -784,6 +784,17 @@
 // wide.
 Optimizer::PassToken CreateGraphicsRobustAccessPass();
 
+// Create descriptor scalar replacement pass.
+// This pass replaces every array variable |desc| that has a DescriptorSet and
+// Binding decorations with a new variable for each element of the array.
+// Suppose |desc| was bound at binding |b|.  Then the variable corresponding to
+// |desc[i]| will have binding |b+i|.  The descriptor set will be the same.  It
+// is assumed that no other variable already has a binding that will used by one
+// of the new variables.  If not, the pass will generate invalid Spir-V.  All
+// accesses to |desc| must be OpAccessChain instructions with a literal index
+// for the first index.
+Optimizer::PassToken CreateDescriptorScalarReplacementPass();
+
 }  // namespace spvtools
 
 #endif  // INCLUDE_SPIRV_TOOLS_OPTIMIZER_HPP_
diff --git a/source/opt/CMakeLists.txt b/source/opt/CMakeLists.txt
index 278f794..2ebad51 100644
--- a/source/opt/CMakeLists.txt
+++ b/source/opt/CMakeLists.txt
@@ -33,6 +33,7 @@
   decompose_initialized_variables_pass.h
   decoration_manager.h
   def_use_manager.h
+  desc_sroa.h
   dominator_analysis.h
   dominator_tree.h
   eliminate_dead_constant_pass.h
@@ -134,6 +135,7 @@
   decompose_initialized_variables_pass.cpp
   decoration_manager.cpp
   def_use_manager.cpp
+  desc_sroa.cpp
   dominator_analysis.cpp
   dominator_tree.cpp
   eliminate_dead_constant_pass.cpp
diff --git a/source/opt/desc_sroa.cpp b/source/opt/desc_sroa.cpp
new file mode 100644
index 0000000..36256ff
--- /dev/null
+++ b/source/opt/desc_sroa.cpp
@@ -0,0 +1,255 @@
+// Copyright (c) 2019 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "source/opt/desc_sroa.h"
+
+#include <source/util/string_utils.h>
+
+namespace spvtools {
+namespace opt {
+
+Pass::Status DescriptorScalarReplacement::Process() {
+  bool modified = false;
+
+  std::vector<Instruction*> vars_to_kill;
+
+  for (Instruction& var : context()->types_values()) {
+    if (IsCandidate(&var)) {
+      modified = true;
+      if (!ReplaceCandidate(&var)) {
+        return Status::Failure;
+      }
+      vars_to_kill.push_back(&var);
+    }
+  }
+
+  for (Instruction* var : vars_to_kill) {
+    context()->KillInst(var);
+  }
+
+  return (modified ? Status::SuccessWithChange : Status::SuccessWithoutChange);
+}
+
+bool DescriptorScalarReplacement::IsCandidate(Instruction* var) {
+  if (var->opcode() != SpvOpVariable) {
+    return false;
+  }
+
+  uint32_t ptr_type_id = var->type_id();
+  Instruction* ptr_type_inst =
+      context()->get_def_use_mgr()->GetDef(ptr_type_id);
+  if (ptr_type_inst->opcode() != SpvOpTypePointer) {
+    return false;
+  }
+
+  uint32_t var_type_id = ptr_type_inst->GetSingleWordInOperand(1);
+  Instruction* var_type_inst =
+      context()->get_def_use_mgr()->GetDef(var_type_id);
+  if (var_type_inst->opcode() != SpvOpTypeArray) {
+    return false;
+  }
+
+  bool has_desc_set_decoration = false;
+  context()->get_decoration_mgr()->ForEachDecoration(
+      var->result_id(), SpvDecorationDescriptorSet,
+      [&has_desc_set_decoration](const Instruction&) {
+        has_desc_set_decoration = true;
+      });
+  if (!has_desc_set_decoration) {
+    return false;
+  }
+
+  bool has_binding_decoration = false;
+  context()->get_decoration_mgr()->ForEachDecoration(
+      var->result_id(), SpvDecorationBinding,
+      [&has_binding_decoration](const Instruction&) {
+        has_binding_decoration = true;
+      });
+  if (!has_binding_decoration) {
+    return false;
+  }
+
+  return true;
+}
+
+bool DescriptorScalarReplacement::ReplaceCandidate(Instruction* var) {
+  std::vector<Instruction*> work_list;
+  bool failed = !get_def_use_mgr()->WhileEachUser(
+      var->result_id(), [this, &work_list](Instruction* use) {
+        if (use->opcode() == SpvOpName) {
+          return true;
+        }
+
+        if (use->IsDecoration()) {
+          return true;
+        }
+
+        switch (use->opcode()) {
+          case SpvOpAccessChain:
+          case SpvOpInBoundsAccessChain:
+            work_list.push_back(use);
+            return true;
+          default:
+            context()->EmitErrorMessage(
+                "Variable cannot be replaced: invalid instruction", use);
+            return false;
+        }
+        return true;
+      });
+
+  if (failed) {
+    return false;
+  }
+
+  for (Instruction* use : work_list) {
+    if (!ReplaceAccessChain(var, use)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool DescriptorScalarReplacement::ReplaceAccessChain(Instruction* var,
+                                                     Instruction* use) {
+  if (use->NumInOperands() <= 1) {
+    context()->EmitErrorMessage(
+        "Variable cannot be replaced: invalid instruction", use);
+    return false;
+  }
+
+  uint32_t idx_id = use->GetSingleWordInOperand(1);
+  const analysis::Constant* idx_const =
+      context()->get_constant_mgr()->FindDeclaredConstant(idx_id);
+  if (idx_const == nullptr) {
+    context()->EmitErrorMessage("Variable cannot be replaced: invalid index",
+                                use);
+    return false;
+  }
+
+  uint32_t idx = idx_const->GetU32();
+  uint32_t replacement_var = GetReplacementVariable(var, idx);
+
+  if (use->NumInOperands() == 2) {
+    // We are not indexing into the replacement variable.  We can replaces the
+    // access chain with the replacement varibale itself.
+    context()->ReplaceAllUsesWith(use->result_id(), replacement_var);
+    context()->KillInst(use);
+    return true;
+  }
+
+  // We need to build a new access chain with the replacement variable as the
+  // base address.
+  Instruction::OperandList new_operands;
+
+  // Same result id and result type.
+  new_operands.emplace_back(use->GetOperand(0));
+  new_operands.emplace_back(use->GetOperand(1));
+
+  // Use the replacement variable as the base address.
+  new_operands.push_back({SPV_OPERAND_TYPE_ID, {replacement_var}});
+
+  // Drop the first index because it is consumed by the replacment, and copy the
+  // rest.
+  for (uint32_t i = 4; i < use->NumOperands(); i++) {
+    new_operands.emplace_back(use->GetOperand(i));
+  }
+
+  use->ReplaceOperands(new_operands);
+  context()->UpdateDefUse(use);
+  return true;
+}
+
+uint32_t DescriptorScalarReplacement::GetReplacementVariable(Instruction* var,
+                                                             uint32_t idx) {
+  auto replacement_vars = replacement_variables_.find(var);
+  if (replacement_vars == replacement_variables_.end()) {
+    uint32_t ptr_type_id = var->type_id();
+    Instruction* ptr_type_inst = get_def_use_mgr()->GetDef(ptr_type_id);
+    assert(ptr_type_inst->opcode() == SpvOpTypePointer &&
+           "Variable should be a pointer to an array.");
+    uint32_t arr_type_id = ptr_type_inst->GetSingleWordInOperand(1);
+    Instruction* arr_type_inst = get_def_use_mgr()->GetDef(arr_type_id);
+    assert(arr_type_inst->opcode() == SpvOpTypeArray &&
+           "Variable should be a pointer to an array.");
+
+    uint32_t array_len_id = arr_type_inst->GetSingleWordInOperand(1);
+    const analysis::Constant* array_len_const =
+        context()->get_constant_mgr()->FindDeclaredConstant(array_len_id);
+    assert(array_len_const != nullptr && "Array length must be a constant.");
+    uint32_t array_len = array_len_const->GetU32();
+
+    replacement_vars = replacement_variables_
+                           .insert({var, std::vector<uint32_t>(array_len, 0)})
+                           .first;
+  }
+
+  if (replacement_vars->second[idx] == 0) {
+    replacement_vars->second[idx] = CreateReplacementVariable(var, idx);
+  }
+
+  return replacement_vars->second[idx];
+}
+
+uint32_t DescriptorScalarReplacement::CreateReplacementVariable(
+    Instruction* var, uint32_t idx) {
+  // The storage class for the new variable is the same as the original.
+  SpvStorageClass storage_class =
+      static_cast<SpvStorageClass>(var->GetSingleWordInOperand(0));
+
+  // The type for the new variable will be a pointer to type of the elements of
+  // the array.
+  uint32_t ptr_type_id = var->type_id();
+  Instruction* ptr_type_inst = get_def_use_mgr()->GetDef(ptr_type_id);
+  assert(ptr_type_inst->opcode() == SpvOpTypePointer &&
+         "Variable should be a pointer to an array.");
+  uint32_t arr_type_id = ptr_type_inst->GetSingleWordInOperand(1);
+  Instruction* arr_type_inst = get_def_use_mgr()->GetDef(arr_type_id);
+  assert(arr_type_inst->opcode() == SpvOpTypeArray &&
+         "Variable should be a pointer to an array.");
+  uint32_t element_type_id = arr_type_inst->GetSingleWordInOperand(0);
+
+  uint32_t ptr_element_type_id = context()->get_type_mgr()->FindPointerToType(
+      element_type_id, storage_class);
+
+  // Create the variable.
+  uint32_t id = TakeNextId();
+  std::unique_ptr<Instruction> variable(
+      new Instruction(context(), SpvOpVariable, ptr_element_type_id, id,
+                      std::initializer_list<Operand>{
+                          {SPV_OPERAND_TYPE_STORAGE_CLASS,
+                           {static_cast<uint32_t>(storage_class)}}}));
+  context()->AddGlobalValue(std::move(variable));
+
+  // Copy all of the decorations to the new variable.  The only difference is
+  // the Binding decoration needs to be adjusted.
+  for (auto old_decoration :
+       get_decoration_mgr()->GetDecorationsFor(var->result_id(), true)) {
+    assert(old_decoration->opcode() == SpvOpDecorate);
+    std::unique_ptr<Instruction> new_decoration(
+        old_decoration->Clone(context()));
+    new_decoration->SetInOperand(0, {id});
+
+    uint32_t decoration = new_decoration->GetSingleWordInOperand(1u);
+    if (decoration == SpvDecorationBinding) {
+      uint32_t new_binding = new_decoration->GetSingleWordInOperand(2) + idx;
+      new_decoration->SetInOperand(2, {new_binding});
+    }
+    context()->AddAnnotationInst(std::move(new_decoration));
+  }
+
+  return id;
+}
+
+}  // namespace opt
+}  // namespace spvtools
diff --git a/source/opt/desc_sroa.h b/source/opt/desc_sroa.h
new file mode 100644
index 0000000..a95c6b5
--- /dev/null
+++ b/source/opt/desc_sroa.h
@@ -0,0 +1,84 @@
+// Copyright (c) 2019 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef SOURCE_OPT_DESC_SROA_H_
+#define SOURCE_OPT_DESC_SROA_H_
+
+#include <cstdio>
+#include <memory>
+#include <queue>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+#include "source/opt/function.h"
+#include "source/opt/pass.h"
+#include "source/opt/type_manager.h"
+
+namespace spvtools {
+namespace opt {
+
+// Documented in optimizer.hpp
+class DescriptorScalarReplacement : public Pass {
+ public:
+  DescriptorScalarReplacement() {}
+
+  const char* name() const override { return "descriptor-scalar-replacement"; }
+
+  Status Process() override;
+
+  IRContext::Analysis GetPreservedAnalyses() override {
+    return IRContext::kAnalysisDefUse |
+           IRContext::kAnalysisInstrToBlockMapping |
+           IRContext::kAnalysisCombinators | IRContext::kAnalysisCFG |
+           IRContext::kAnalysisConstants | IRContext::kAnalysisTypes;
+  }
+
+ private:
+  // Returns true if |var| is an OpVariable instruction that represents a
+  // descriptor array.  These are the variables that we want to replace.
+  bool IsCandidate(Instruction* var);
+
+  // Replaces all references to |var| by new variables, one for each element of
+  // the array |var|.  The binding for the new variables corresponding to
+  // element i will be the binding of |var| plus i.  Returns true if successful.
+  bool ReplaceCandidate(Instruction* var);
+
+  // Replaces the base address |var| in the OpAccessChain or
+  // OpInBoundsAccessChain instruction |use| by the variable that the access
+  // chain accesses.  The first index in |use| must be an |OpConstant|.  Returns
+  // |true| if successful.
+  bool ReplaceAccessChain(Instruction* var, Instruction* use);
+
+  // Returns the id of the variable that will be used to replace the |idx|th
+  // element of |var|.  The variable is created if it has not already been
+  // created.
+  uint32_t GetReplacementVariable(Instruction* var, uint32_t idx);
+
+  // Returns the id of a new variable that can be used to replace the |idx|th
+  // element of |var|.
+  uint32_t CreateReplacementVariable(Instruction* var, uint32_t idx);
+
+  // A map from an OpVariable instruction to the set of variables that will be
+  // used to replace it. The entry |replacement_variables_[var][i]| is the id of
+  // a variable that will be used in the place of the the ith element of the
+  // array |var|. If the entry is |0|, then the variable has not been
+  // created yet.
+  std::map<Instruction*, std::vector<uint32_t>> replacement_variables_;
+};
+
+}  // namespace opt
+}  // namespace spvtools
+
+#endif  // SOURCE_OPT_DESC_SROA_H_
diff --git a/source/opt/ir_context.cpp b/source/opt/ir_context.cpp
index b600f12..823c2b7 100644
--- a/source/opt/ir_context.cpp
+++ b/source/opt/ir_context.cpp
@@ -788,6 +788,42 @@
   return modified;
 }
 
+void IRContext::EmitErrorMessage(std::string message, Instruction* inst) {
+  if (!consumer()) {
+    return;
+  }
+
+  Instruction* line_inst = inst;
+  while (line_inst != nullptr) {  // Stop at the beginning of the basic block.
+    if (!line_inst->dbg_line_insts().empty()) {
+      line_inst = &line_inst->dbg_line_insts().back();
+      if (line_inst->opcode() == SpvOpNoLine) {
+        line_inst = nullptr;
+      }
+      break;
+    }
+    line_inst = line_inst->PreviousNode();
+  }
+
+  uint32_t line_number = 0;
+  uint32_t col_number = 0;
+  char* source = nullptr;
+  if (line_inst != nullptr) {
+    Instruction* file_name =
+        get_def_use_mgr()->GetDef(line_inst->GetSingleWordInOperand(0));
+    source = reinterpret_cast<char*>(&file_name->GetInOperand(0).words[0]);
+
+    // Get the line number and column number.
+    line_number = line_inst->GetSingleWordInOperand(1);
+    col_number = line_inst->GetSingleWordInOperand(2);
+  }
+
+  message +=
+      "\n  " + inst->PrettyPrint(SPV_BINARY_TO_TEXT_OPTION_FRIENDLY_NAMES);
+  consumer()(SPV_MSG_ERROR, source, {line_number, col_number, 0},
+             message.c_str());
+}
+
 // Gets the dominator analysis for function |f|.
 DominatorAnalysis* IRContext::GetDominatorAnalysis(const Function* f) {
   if (!AreAnalysesValid(kAnalysisDominatorAnalysis)) {
diff --git a/source/opt/ir_context.h b/source/opt/ir_context.h
index 308f633..05df9c0 100644
--- a/source/opt/ir_context.h
+++ b/source/opt/ir_context.h
@@ -556,6 +556,10 @@
   bool ProcessCallTreeFromRoots(ProcessFunction& pfn,
                                 std::queue<uint32_t>* roots);
 
+  // Emmits a error message to the message consumer indicating the error
+  // described by |message| occurred in |inst|.
+  void EmitErrorMessage(std::string message, Instruction* inst);
+
  private:
   // Builds the def-use manager from scratch, even if it was already valid.
   void BuildDefUseManager() {
diff --git a/source/opt/optimizer.cpp b/source/opt/optimizer.cpp
index 2dd1708..4cc5e97 100644
--- a/source/opt/optimizer.cpp
+++ b/source/opt/optimizer.cpp
@@ -315,6 +315,8 @@
     RegisterPass(CreateCombineAccessChainsPass());
   } else if (pass_name == "convert-local-access-chains") {
     RegisterPass(CreateLocalAccessChainConvertPass());
+  } else if (pass_name == "descriptor-scalar-replacement") {
+    RegisterPass(CreateDescriptorScalarReplacementPass());
   } else if (pass_name == "eliminate-dead-code-aggressive") {
     RegisterPass(CreateAggressiveDCEPass());
   } else if (pass_name == "propagate-line-info") {
@@ -886,4 +888,9 @@
       MakeUnique<opt::GraphicsRobustAccessPass>());
 }
 
+Optimizer::PassToken CreateDescriptorScalarReplacementPass() {
+  return MakeUnique<Optimizer::PassToken::Impl>(
+      MakeUnique<opt::DescriptorScalarReplacement>());
+}
+
 }  // namespace spvtools
diff --git a/source/opt/passes.h b/source/opt/passes.h
index 5eddc22..86588f7 100644
--- a/source/opt/passes.h
+++ b/source/opt/passes.h
@@ -29,6 +29,7 @@
 #include "source/opt/dead_insert_elim_pass.h"
 #include "source/opt/dead_variable_elimination.h"
 #include "source/opt/decompose_initialized_variables_pass.h"
+#include "source/opt/desc_sroa.h"
 #include "source/opt/eliminate_dead_constant_pass.h"
 #include "source/opt/eliminate_dead_functions_pass.h"
 #include "source/opt/eliminate_dead_members_pass.h"
diff --git a/source/util/string_utils.h b/source/util/string_utils.h
index f1cd179..4282aa9 100644
--- a/source/util/string_utils.h
+++ b/source/util/string_utils.h
@@ -15,8 +15,10 @@
 #ifndef SOURCE_UTIL_STRING_UTILS_H_
 #define SOURCE_UTIL_STRING_UTILS_H_
 
+#include <assert.h>
 #include <sstream>
 #include <string>
+#include <vector>
 
 #include "source/util/string_utils.h"
 
@@ -42,6 +44,48 @@
 // string will be empty.
 std::pair<std::string, std::string> SplitFlagArgs(const std::string& flag);
 
+// Encodes a string as a sequence of words, using the SPIR-V encoding.
+inline std::vector<uint32_t> MakeVector(std::string input) {
+  std::vector<uint32_t> result;
+  uint32_t word = 0;
+  size_t num_bytes = input.size();
+  // SPIR-V strings are null-terminated.  The byte_index == num_bytes
+  // case is used to push the terminating null byte.
+  for (size_t byte_index = 0; byte_index <= num_bytes; byte_index++) {
+    const auto new_byte =
+        (byte_index < num_bytes ? uint8_t(input[byte_index]) : uint8_t(0));
+    word |= (new_byte << (8 * (byte_index % sizeof(uint32_t))));
+    if (3 == (byte_index % sizeof(uint32_t))) {
+      result.push_back(word);
+      word = 0;
+    }
+  }
+  // Emit a trailing partial word.
+  if ((num_bytes + 1) % sizeof(uint32_t)) {
+    result.push_back(word);
+  }
+  return result;
+}
+
+// Decode a string from a sequence of words, using the SPIR-V encoding.
+template <class VectorType>
+inline std::string MakeString(const VectorType& words) {
+  std::string result;
+
+  for (uint32_t word : words) {
+    for (int byte_index = 0; byte_index < 4; byte_index++) {
+      uint32_t extracted_word = (word >> (8 * byte_index)) & 0xFF;
+      char c = static_cast<char>(extracted_word);
+      if (c == 0) {
+        return result;
+      }
+      result += c;
+    }
+  }
+  assert(false && "Did not find terminating null for the string.");
+  return result;
+}  // namespace utils
+
 }  // namespace utils
 }  // namespace spvtools
 
diff --git a/test/assembly_context_test.cpp b/test/assembly_context_test.cpp
index ee0bb24..c8aa06b 100644
--- a/test/assembly_context_test.cpp
+++ b/test/assembly_context_test.cpp
@@ -17,6 +17,7 @@
 
 #include "gmock/gmock.h"
 #include "source/instruction.h"
+#include "source/util/string_utils.h"
 #include "test/unit_spirv.h"
 
 namespace spvtools {
@@ -40,9 +41,8 @@
   ASSERT_EQ(SPV_SUCCESS,
             context.binaryEncodeString(GetParam().str.c_str(), &inst));
   // We already trust MakeVector
-  EXPECT_THAT(inst.words,
-              Eq(Concatenate({GetParam().initial_contents,
-                              spvtest::MakeVector(GetParam().str)})));
+  EXPECT_THAT(inst.words, Eq(Concatenate({GetParam().initial_contents,
+                                          utils::MakeVector(GetParam().str)})));
 }
 
 // clang-format off
diff --git a/test/binary_parse_test.cpp b/test/binary_parse_test.cpp
index b966102..54664fc 100644
--- a/test/binary_parse_test.cpp
+++ b/test/binary_parse_test.cpp
@@ -21,6 +21,7 @@
 #include "gmock/gmock.h"
 #include "source/latest_version_opencl_std_header.h"
 #include "source/table.h"
+#include "source/util/string_utils.h"
 #include "test/test_fixture.h"
 #include "test/unit_spirv.h"
 
@@ -39,7 +40,7 @@
 
 using ::spvtest::Concatenate;
 using ::spvtest::MakeInstruction;
-using ::spvtest::MakeVector;
+using utils::MakeVector;
 using ::spvtest::ScopedContext;
 using ::testing::_;
 using ::testing::AnyOf;
diff --git a/test/comment_test.cpp b/test/comment_test.cpp
index f46b72a..49f8df6 100644
--- a/test/comment_test.cpp
+++ b/test/comment_test.cpp
@@ -15,6 +15,7 @@
 #include <string>
 
 #include "gmock/gmock.h"
+#include "source/util/string_utils.h"
 #include "test/test_fixture.h"
 #include "test/unit_spirv.h"
 
@@ -23,7 +24,7 @@
 
 using spvtest::Concatenate;
 using spvtest::MakeInstruction;
-using spvtest::MakeVector;
+using utils::MakeVector;
 using spvtest::TextToBinaryTest;
 using testing::Eq;
 
diff --git a/test/ext_inst.debuginfo_test.cpp b/test/ext_inst.debuginfo_test.cpp
index ec012e0..9090c24 100644
--- a/test/ext_inst.debuginfo_test.cpp
+++ b/test/ext_inst.debuginfo_test.cpp
@@ -17,6 +17,7 @@
 
 #include "DebugInfo.h"
 #include "gmock/gmock.h"
+#include "source/util/string_utils.h"
 #include "test/test_fixture.h"
 #include "test/unit_spirv.h"
 
@@ -31,7 +32,7 @@
 
 using spvtest::Concatenate;
 using spvtest::MakeInstruction;
-using spvtest::MakeVector;
+using utils::MakeVector;
 using testing::Eq;
 
 struct InstructionCase {
diff --git a/test/ext_inst.opencl_test.cpp b/test/ext_inst.opencl_test.cpp
index 7dd903e..7547d92 100644
--- a/test/ext_inst.opencl_test.cpp
+++ b/test/ext_inst.opencl_test.cpp
@@ -17,6 +17,7 @@
 
 #include "gmock/gmock.h"
 #include "source/latest_version_opencl_std_header.h"
+#include "source/util/string_utils.h"
 #include "test/test_fixture.h"
 #include "test/unit_spirv.h"
 
@@ -25,7 +26,7 @@
 
 using spvtest::Concatenate;
 using spvtest::MakeInstruction;
-using spvtest::MakeVector;
+using utils::MakeVector;
 using spvtest::TextToBinaryTest;
 using testing::Eq;
 
diff --git a/test/opt/CMakeLists.txt b/test/opt/CMakeLists.txt
index 6131c9b..366a61f 100644
--- a/test/opt/CMakeLists.txt
+++ b/test/opt/CMakeLists.txt
@@ -34,6 +34,7 @@
        decompose_initialized_variables_test.cpp
        decoration_manager_test.cpp
        def_use_test.cpp
+       desc_sroa_test.cpp
        eliminate_dead_const_test.cpp
        eliminate_dead_functions_test.cpp
        eliminate_dead_member_test.cpp
diff --git a/test/opt/decoration_manager_test.cpp b/test/opt/decoration_manager_test.cpp
index 3eb3ef5..fcfbff0 100644
--- a/test/opt/decoration_manager_test.cpp
+++ b/test/opt/decoration_manager_test.cpp
@@ -22,6 +22,7 @@
 #include "source/opt/decoration_manager.h"
 #include "source/opt/ir_context.h"
 #include "source/spirv_constant.h"
+#include "source/util/string_utils.h"
 #include "test/unit_spirv.h"
 
 namespace spvtools {
@@ -29,7 +30,7 @@
 namespace analysis {
 namespace {
 
-using spvtest::MakeVector;
+using utils::MakeVector;
 
 class DecorationManagerTest : public ::testing::Test {
  public:
diff --git a/test/opt/desc_sroa_test.cpp b/test/opt/desc_sroa_test.cpp
new file mode 100644
index 0000000..04ea0f7
--- /dev/null
+++ b/test/opt/desc_sroa_test.cpp
@@ -0,0 +1,209 @@
+// Copyright (c) 2019 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <string>
+
+#include "gmock/gmock.h"
+#include "test/opt/assembly_builder.h"
+#include "test/opt/pass_fixture.h"
+#include "test/opt/pass_utils.h"
+
+namespace spvtools {
+namespace opt {
+namespace {
+
+using DescriptorScalarReplacementTest = PassTest<::testing::Test>;
+
+TEST_F(DescriptorScalarReplacementTest, ExpandTexture) {
+  const std::string text = R"(
+; CHECK: OpDecorate [[var1:%\w+]] DescriptorSet 0
+; CHECK: OpDecorate [[var1]] Binding 0
+; CHECK: OpDecorate [[var2:%\w+]] DescriptorSet 0
+; CHECK: OpDecorate [[var2]] Binding 1
+; CHECK: OpDecorate [[var3:%\w+]] DescriptorSet 0
+; CHECK: OpDecorate [[var3]] Binding 2
+; CHECK: OpDecorate [[var4:%\w+]] DescriptorSet 0
+; CHECK: OpDecorate [[var4]] Binding 3
+; CHECK: OpDecorate [[var5:%\w+]] DescriptorSet 0
+; CHECK: OpDecorate [[var5]] Binding 4
+; CHECK: [[image_type:%\w+]] = OpTypeImage
+; CHECK: [[ptr_type:%\w+]] = OpTypePointer UniformConstant [[image_type]]
+; CHECK: [[var1]] = OpVariable [[ptr_type]] UniformConstant
+; CHECK: [[var2]] = OpVariable [[ptr_type]] UniformConstant
+; CHECK: [[var3]] = OpVariable [[ptr_type]] UniformConstant
+; CHECK: [[var4]] = OpVariable [[ptr_type]] UniformConstant
+; CHECK: [[var5]] = OpVariable [[ptr_type]] UniformConstant
+; CHECK: OpLoad [[image_type]] [[var1]]
+; CHECK: OpLoad [[image_type]] [[var2]]
+; CHECK: OpLoad [[image_type]] [[var3]]
+; CHECK: OpLoad [[image_type]] [[var4]]
+; CHECK: OpLoad [[image_type]] [[var5]]
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main"
+               OpExecutionMode %main OriginUpperLeft
+               OpSource HLSL 600
+               OpDecorate %MyTextures DescriptorSet 0
+               OpDecorate %MyTextures Binding 0
+        %int = OpTypeInt 32 1
+      %int_0 = OpConstant %int 0
+      %int_1 = OpConstant %int 1
+      %int_2 = OpConstant %int 2
+      %int_3 = OpConstant %int 3
+      %int_4 = OpConstant %int 4
+       %uint = OpTypeInt 32 0
+     %uint_5 = OpConstant %uint 5
+      %float = OpTypeFloat 32
+%type_2d_image = OpTypeImage %float 2D 2 0 0 1 Unknown
+%_arr_type_2d_image_uint_5 = OpTypeArray %type_2d_image %uint_5
+%_ptr_UniformConstant__arr_type_2d_image_uint_5 = OpTypePointer UniformConstant %_arr_type_2d_image_uint_5
+    %v2float = OpTypeVector %float 2
+       %void = OpTypeVoid
+         %26 = OpTypeFunction %void
+%_ptr_UniformConstant_type_2d_image = OpTypePointer UniformConstant %type_2d_image
+ %MyTextures = OpVariable %_ptr_UniformConstant__arr_type_2d_image_uint_5 UniformConstant
+       %main = OpFunction %void None %26
+         %28 = OpLabel
+         %29 = OpUndef %v2float
+         %30 = OpAccessChain %_ptr_UniformConstant_type_2d_image %MyTextures %int_0
+         %31 = OpLoad %type_2d_image %30
+         %35 = OpAccessChain %_ptr_UniformConstant_type_2d_image %MyTextures %int_1
+         %36 = OpLoad %type_2d_image %35
+         %40 = OpAccessChain %_ptr_UniformConstant_type_2d_image %MyTextures %int_2
+         %41 = OpLoad %type_2d_image %40
+         %45 = OpAccessChain %_ptr_UniformConstant_type_2d_image %MyTextures %int_3
+         %46 = OpLoad %type_2d_image %45
+         %50 = OpAccessChain %_ptr_UniformConstant_type_2d_image %MyTextures %int_4
+         %51 = OpLoad %type_2d_image %50
+               OpReturn
+               OpFunctionEnd
+
+  )";
+
+  SinglePassRunAndMatch<DescriptorScalarReplacement>(text, true);
+}
+
+TEST_F(DescriptorScalarReplacementTest, ExpandSampler) {
+  const std::string text = R"(
+; CHECK: OpDecorate [[var1:%\w+]] DescriptorSet 0
+; CHECK: OpDecorate [[var1]] Binding 1
+; CHECK: OpDecorate [[var2:%\w+]] DescriptorSet 0
+; CHECK: OpDecorate [[var2]] Binding 2
+; CHECK: OpDecorate [[var3:%\w+]] DescriptorSet 0
+; CHECK: OpDecorate [[var3]] Binding 3
+; CHECK: [[sampler_type:%\w+]] = OpTypeSampler
+; CHECK: [[ptr_type:%\w+]] = OpTypePointer UniformConstant [[sampler_type]]
+; CHECK: [[var1]] = OpVariable [[ptr_type]] UniformConstant
+; CHECK: [[var2]] = OpVariable [[ptr_type]] UniformConstant
+; CHECK: [[var3]] = OpVariable [[ptr_type]] UniformConstant
+; CHECK: OpLoad [[sampler_type]] [[var1]]
+; CHECK: OpLoad [[sampler_type]] [[var2]]
+; CHECK: OpLoad [[sampler_type]] [[var3]]
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main"
+               OpExecutionMode %main OriginUpperLeft
+               OpSource HLSL 600
+               OpDecorate %MySampler DescriptorSet 0
+               OpDecorate %MySampler Binding 1
+        %int = OpTypeInt 32 1
+      %int_0 = OpConstant %int 0
+      %int_1 = OpConstant %int 1
+      %int_2 = OpConstant %int 2
+       %uint = OpTypeInt 32 0
+     %uint_3 = OpConstant %uint 3
+%type_sampler = OpTypeSampler
+%_arr_type_sampler_uint_3 = OpTypeArray %type_sampler %uint_3
+%_ptr_UniformConstant__arr_type_sampler_uint_3 = OpTypePointer UniformConstant %_arr_type_sampler_uint_3
+       %void = OpTypeVoid
+         %26 = OpTypeFunction %void
+%_ptr_UniformConstant_type_sampler = OpTypePointer UniformConstant %type_sampler
+  %MySampler = OpVariable %_ptr_UniformConstant__arr_type_sampler_uint_3 UniformConstant
+       %main = OpFunction %void None %26
+         %28 = OpLabel
+         %31 = OpAccessChain %_ptr_UniformConstant_type_sampler %MySampler %int_0
+         %32 = OpLoad %type_sampler %31
+         %35 = OpAccessChain %_ptr_UniformConstant_type_sampler %MySampler %int_1
+         %36 = OpLoad %type_sampler %35
+         %40 = OpAccessChain %_ptr_UniformConstant_type_sampler %MySampler %int_2
+         %41 = OpLoad %type_sampler %40
+               OpReturn
+               OpFunctionEnd
+  )";
+
+  SinglePassRunAndMatch<DescriptorScalarReplacement>(text, true);
+}
+
+TEST_F(DescriptorScalarReplacementTest, ExpandSSBO) {
+  // Tests the expansion of an SSBO.  Also check that an access chain with more
+  // than 1 index is correctly handled.
+  const std::string text = R"(
+; CHECK: OpDecorate [[var1:%\w+]] DescriptorSet 0
+; CHECK: OpDecorate [[var1]] Binding 0
+; CHECK: OpDecorate [[var2:%\w+]] DescriptorSet 0
+; CHECK: OpDecorate [[var2]] Binding 1
+; CHECK: OpTypeStruct
+; CHECK: [[struct_type:%\w+]] = OpTypeStruct
+; CHECK: [[ptr_type:%\w+]] = OpTypePointer Uniform [[struct_type]]
+; CHECK: [[var1]] = OpVariable [[ptr_type]] Uniform
+; CHECK: [[var2]] = OpVariable [[ptr_type]] Uniform
+; CHECK: [[ac1:%\w+]] = OpAccessChain %_ptr_Uniform_v4float [[var1]] %uint_0 %uint_0 %uint_0
+; CHECK: OpLoad %v4float [[ac1]]
+; CHECK: [[ac2:%\w+]] = OpAccessChain %_ptr_Uniform_v4float [[var2]] %uint_0 %uint_0 %uint_0
+; CHECK: OpLoad %v4float [[ac2]]
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main"
+               OpExecutionMode %main OriginUpperLeft
+               OpSource HLSL 600
+               OpDecorate %buffers DescriptorSet 0
+               OpDecorate %buffers Binding 0
+               OpMemberDecorate %S 0 Offset 0
+               OpDecorate %_runtimearr_S ArrayStride 16
+               OpMemberDecorate %type_StructuredBuffer_S 0 Offset 0
+               OpMemberDecorate %type_StructuredBuffer_S 0 NonWritable
+               OpDecorate %type_StructuredBuffer_S BufferBlock
+       %uint = OpTypeInt 32 0
+     %uint_0 = OpConstant %uint 0
+      %uint_1 = OpConstant %uint 1
+     %uint_2 = OpConstant %uint 2
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+          %S = OpTypeStruct %v4float
+%_runtimearr_S = OpTypeRuntimeArray %S
+%type_StructuredBuffer_S = OpTypeStruct %_runtimearr_S
+%_arr_type_StructuredBuffer_S_uint_2 = OpTypeArray %type_StructuredBuffer_S %uint_2
+%_ptr_Uniform__arr_type_StructuredBuffer_S_uint_2 = OpTypePointer Uniform %_arr_type_StructuredBuffer_S_uint_2
+%_ptr_Uniform_type_StructuredBuffer_S = OpTypePointer Uniform %type_StructuredBuffer_S
+       %void = OpTypeVoid
+         %19 = OpTypeFunction %void
+%_ptr_Uniform_v4float = OpTypePointer Uniform %v4float
+    %buffers = OpVariable %_ptr_Uniform__arr_type_StructuredBuffer_S_uint_2 Uniform
+       %main = OpFunction %void None %19
+         %21 = OpLabel
+         %22 = OpAccessChain %_ptr_Uniform_v4float %buffers %uint_0 %uint_0 %uint_0 %uint_0
+         %23 = OpLoad %v4float %22
+         %24 = OpAccessChain %_ptr_Uniform_type_StructuredBuffer_S %buffers %uint_1
+         %25 = OpAccessChain %_ptr_Uniform_v4float %24 %uint_0 %uint_0 %uint_0
+         %26 = OpLoad %v4float %25
+               OpReturn
+               OpFunctionEnd
+  )";
+
+  SinglePassRunAndMatch<DescriptorScalarReplacement>(text, true);
+}
+
+}  // namespace
+}  // namespace opt
+}  // namespace spvtools
diff --git a/test/text_to_binary.annotation_test.cpp b/test/text_to_binary.annotation_test.cpp
index 69a4861..61bdf64 100644
--- a/test/text_to_binary.annotation_test.cpp
+++ b/test/text_to_binary.annotation_test.cpp
@@ -21,6 +21,7 @@
 #include <vector>
 
 #include "gmock/gmock.h"
+#include "source/util/string_utils.h"
 #include "test/test_fixture.h"
 #include "test/unit_spirv.h"
 
@@ -29,7 +30,7 @@
 
 using spvtest::EnumCase;
 using spvtest::MakeInstruction;
-using spvtest::MakeVector;
+using utils::MakeVector;
 using spvtest::TextToBinaryTest;
 using ::testing::Combine;
 using ::testing::Eq;
diff --git a/test/text_to_binary.debug_test.cpp b/test/text_to_binary.debug_test.cpp
index f9a4645..39ba5c5 100644
--- a/test/text_to_binary.debug_test.cpp
+++ b/test/text_to_binary.debug_test.cpp
@@ -19,6 +19,7 @@
 #include <vector>
 
 #include "gmock/gmock.h"
+#include "source/util/string_utils.h"
 #include "test/test_fixture.h"
 #include "test/unit_spirv.h"
 
@@ -26,7 +27,7 @@
 namespace {
 
 using spvtest::MakeInstruction;
-using spvtest::MakeVector;
+using utils::MakeVector;
 using spvtest::TextToBinaryTest;
 using ::testing::Eq;
 
diff --git a/test/text_to_binary.extension_test.cpp b/test/text_to_binary.extension_test.cpp
index 84552b5..9408e9a 100644
--- a/test/text_to_binary.extension_test.cpp
+++ b/test/text_to_binary.extension_test.cpp
@@ -22,6 +22,7 @@
 #include "gmock/gmock.h"
 #include "source/latest_version_glsl_std_450_header.h"
 #include "source/latest_version_opencl_std_header.h"
+#include "source/util/string_utils.h"
 #include "test/test_fixture.h"
 #include "test/unit_spirv.h"
 
@@ -30,7 +31,7 @@
 
 using spvtest::Concatenate;
 using spvtest::MakeInstruction;
-using spvtest::MakeVector;
+using utils::MakeVector;
 using spvtest::TextToBinaryTest;
 using ::testing::Combine;
 using ::testing::Eq;
diff --git a/test/text_to_binary.mode_setting_test.cpp b/test/text_to_binary.mode_setting_test.cpp
index d1b69dd..8ddf421 100644
--- a/test/text_to_binary.mode_setting_test.cpp
+++ b/test/text_to_binary.mode_setting_test.cpp
@@ -20,6 +20,7 @@
 #include <vector>
 
 #include "gmock/gmock.h"
+#include "source/util/string_utils.h"
 #include "test/test_fixture.h"
 #include "test/unit_spirv.h"
 
@@ -28,7 +29,7 @@
 
 using spvtest::EnumCase;
 using spvtest::MakeInstruction;
-using spvtest::MakeVector;
+using utils::MakeVector;
 using ::testing::Combine;
 using ::testing::Eq;
 using ::testing::TestWithParam;
diff --git a/test/unit_spirv.cpp b/test/unit_spirv.cpp
index 84ed87a..0854439 100644
--- a/test/unit_spirv.cpp
+++ b/test/unit_spirv.cpp
@@ -15,12 +15,13 @@
 #include "test/unit_spirv.h"
 
 #include "gmock/gmock.h"
+#include "source/util/string_utils.h"
 #include "test/test_fixture.h"
 
 namespace spvtools {
 namespace {
 
-using spvtest::MakeVector;
+using utils::MakeVector;
 using ::testing::Eq;
 using Words = std::vector<uint32_t>;
 
diff --git a/test/unit_spirv.h b/test/unit_spirv.h
index 2244288..3264662 100644
--- a/test/unit_spirv.h
+++ b/test/unit_spirv.h
@@ -133,29 +133,6 @@
   return result;
 }
 
-// Encodes a string as a sequence of words, using the SPIR-V encoding.
-inline std::vector<uint32_t> MakeVector(std::string input) {
-  std::vector<uint32_t> result;
-  uint32_t word = 0;
-  size_t num_bytes = input.size();
-  // SPIR-V strings are null-terminated.  The byte_index == num_bytes
-  // case is used to push the terminating null byte.
-  for (size_t byte_index = 0; byte_index <= num_bytes; byte_index++) {
-    const auto new_byte =
-        (byte_index < num_bytes ? uint8_t(input[byte_index]) : uint8_t(0));
-    word |= (new_byte << (8 * (byte_index % sizeof(uint32_t))));
-    if (3 == (byte_index % sizeof(uint32_t))) {
-      result.push_back(word);
-      word = 0;
-    }
-  }
-  // Emit a trailing partial word.
-  if ((num_bytes + 1) % sizeof(uint32_t)) {
-    result.push_back(word);
-  }
-  return result;
-}
-
 // A type for easily creating spv_text_t values, with an implicit conversion to
 // spv_text.
 struct AutoText {
diff --git a/tools/opt/opt.cpp b/tools/opt/opt.cpp
index 8dcf933..c18b64c 100644
--- a/tools/opt/opt.cpp
+++ b/tools/opt/opt.cpp
@@ -147,6 +147,15 @@
                around known issues with some Vulkan drivers for initialize
                variables.)");
   printf(R"(
+  --descriptor-scalar-replacement
+               Replaces every array variable |desc| that has a DescriptorSet
+               and Binding decorations with a new variable for each element of
+               the array.  Suppose |desc| was bound at binding |b|.  Then the
+               variable corresponding to |desc[i]| will have binding |b+i|.
+               The descriptor set will be the same.  All accesses to |desc|
+               must be in OpAccessChain instructions with a literal index for
+               the first index.)");
+  printf(R"(
   --eliminate-dead-branches
                Convert conditional branches with constant condition to the
                indicated unconditional brranch. Delete all resulting dead