diff --git a/tools/spirv/CMakeLists.txt b/tools/spirv/CMakeLists.txt
index af51f86..5775510 100644
--- a/tools/spirv/CMakeLists.txt
+++ b/tools/spirv/CMakeLists.txt
@@ -12,6 +12,7 @@ include_directories(../..)
 
 set(SOURCES
     main.cpp
+    assembler_table.cpp
     disassemble.cpp
     header.cpp
     doc.cpp
diff --git a/tools/spirv/OclDoc.cpp b/tools/spirv/OclDoc.cpp
index c94eae2..ea47d42 100644
--- a/tools/spirv/OclDoc.cpp
+++ b/tools/spirv/OclDoc.cpp
@@ -28,11 +28,14 @@
 #include "headers/spirv.hpp"
 #include "headers/OpenCL.std.h"
 
-#include "doc.h"
 #include "OclDoc.h"
 
+#include "assembler_table.h"
+#include "doc.h"
+
 #include <stdio.h>
 #include <string.h>
+#include <cassert>
 #include <algorithm>
 #include <map>
 
@@ -2358,4 +2361,27 @@ void PrintOclCommonDoc()
     PrintOclDoc(SPIROpenCLCommonVersion);
 }
 
+void PrintOclInstructionsTable(std::ostream& out) {
+  ParameterizeBuiltins(SPIROpenCLCommonVersion);
+
+  out << R"(
+// OpenCL extended instructions table, one instruction per line.
+// All instructions have a result type and a result ID.
+// Fields in this file are:
+//  - name
+//  - extended instruction index
+//  - EmptyList, or List of operand classes.
+)";
+  for (int i = 0; i < OclExtInstCeiling; ++i) {
+    const BuiltInFunctionParameters& inst = BuiltInDesc[i];
+    // Skip gaps in the enum space, if any.
+    if (0 == strcmp("unknown", inst.opName)) continue;
+    assert(inst.hasType());
+    assert(inst.hasResult());
+    out << "ExtInst(" << inst.opName << ", " << i << ", ";
+    PrintOperandClasses(inst.operands.classes(), out);
+    out << ")" << std::endl;
+  }
+}
+
 };  // end namespace spv
diff --git a/tools/spirv/OclDoc.h b/tools/spirv/OclDoc.h
index 8568880..7cf8a31 100644
--- a/tools/spirv/OclDoc.h
+++ b/tools/spirv/OclDoc.h
@@ -35,6 +35,8 @@
 #include <map>
 #include "headers/spirv.hpp"
 
+#include "doc.h"
+
 namespace spv {
 
 void OclGetDebugNames(const char** names);
@@ -189,6 +191,8 @@ public:
     int getImageType(int op) { return Type[op]; }
     AccessQualifier getAccessQualifier(int op) { return accessQualifier[op]; }
 
+    const std::vector<OperandClass>& classes() const  { return opClass; }
+
 protected:
     std::vector<OperandClass> opClass;
     std::vector<const char*> desc;
@@ -307,4 +311,7 @@ protected:
 // Print out the OpenCL common (all spec revisions) documentation.
 void PrintOclCommonDoc();
 
+// Prints the OpenCL instructions table, for consumption by SPIR-V Tools.
+void PrintOclInstructionsTable(std::ostream& out);
+
 };  // end namespace spv
diff --git a/tools/spirv/assembler_table.cpp b/tools/spirv/assembler_table.cpp
new file mode 100644
index 0000000..85bca89
--- /dev/null
+++ b/tools/spirv/assembler_table.cpp
@@ -0,0 +1,214 @@
+// Copyright (c) 2015 The Khronos Group Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and/or associated documentation files (the
+// "Materials"), to deal in the Materials without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Materials, and to
+// permit persons to whom the Materials are furnished to do so, subject to
+// the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Materials.
+//
+// MODIFICATIONS TO THIS FILE MAY MEAN IT NO LONGER ACCURATELY REFLECTS
+// KHRONOS STANDARDS. THE UNMODIFIED, NORMATIVE VERSIONS OF KHRONOS
+// SPECIFICATIONS AND HEADER INFORMATION ARE LOCATED AT
+//    https://www.khronos.org/registry/
+//
+// THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+// MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
+
+#include "assembler_table.h"
+
+#include <cassert>
+#include <cstring>
+#include <sstream>
+
+#include "doc.h"
+
+namespace spv {
+
+namespace {
+
+// Returns true if the given instruction can vary in width.
+bool IsVariableLength(const InstructionParameters& inst) {
+  const OperandParameters& operands = inst.operands;
+  for (int i = 0; i < operands.getNum() ; i++) {
+    switch (operands.getClass(i)) {
+      case spv::OperandOptionalId:
+      case spv::OperandOptionalImage:
+      case spv::OperandVariableIds:
+      case spv::OperandOptionalLiteral:
+      case spv::OperandOptionalLiteralString:
+      case spv::OperandVariableLiterals:
+      case spv::OperandVariableIdLiteral:
+      case spv::OperandVariableLiteralId:
+      case spv::OperandLiteralString:
+        return true;
+      default:
+        break;
+    }
+  }
+  return false;
+}
+
+// Returns a string for the given operand class, or nullptr if it's invalid.
+const char* GetOperandClassString(OperandClass operandClass) {
+  switch (operandClass) {
+#define CASE(X) case X: return #X;
+    CASE(OperandNone)
+    CASE(OperandId)
+    CASE(OperandOptionalId)
+    CASE(OperandOptionalImage)
+    CASE(OperandVariableIds)
+    CASE(OperandOptionalLiteral)
+    CASE(OperandOptionalLiteralString)
+    CASE(OperandVariableLiterals)
+    CASE(OperandVariableIdLiteral)
+    CASE(OperandVariableLiteralId)
+    CASE(OperandLiteralNumber)
+    CASE(OperandLiteralString)
+    CASE(OperandSource)
+    CASE(OperandExecutionModel)
+    CASE(OperandAddressing)
+    CASE(OperandMemory)
+    CASE(OperandExecutionMode)
+    CASE(OperandStorage)
+    CASE(OperandDimensionality)
+    CASE(OperandSamplerAddressingMode)
+    CASE(OperandSamplerFilterMode)
+    CASE(OperandSamplerImageFormat)
+    CASE(OperandImageChannelOrder)
+    CASE(OperandImageChannelDataType)
+    CASE(OperandImageOperands)
+    CASE(OperandFPFastMath)
+    CASE(OperandFPRoundingMode)
+    CASE(OperandLinkageType)
+    CASE(OperandAccessQualifier)
+    CASE(OperandFuncParamAttr)
+    CASE(OperandDecoration)
+    CASE(OperandBuiltIn)
+    CASE(OperandSelect)
+    CASE(OperandLoop)
+    CASE(OperandFunction)
+    CASE(OperandMemorySemantics)
+    CASE(OperandMemoryAccess)
+    CASE(OperandScope)
+    CASE(OperandGroupOperation)
+    CASE(OperandKernelEnqueueFlags)
+    CASE(OperandKernelProfilingInfo)
+    CASE(OperandCapability)
+    CASE(OperandOpcode)
+#undef CASE
+
+    case OperandCount:
+    default:
+      break;
+  }
+  return nullptr;
+}
+} // anonymous namespace
+
+// Prints a listing of the operand kinds for the given instruction.
+// If the list is empty, then emit just "EmptyList",
+// otherwise the output looks like a call to the "List" macro.
+void PrintOperandClasses(const std::vector<OperandClass>& classes, std::ostream& out) {
+  std::stringstream contents;
+  int numPrinted = 0;
+  for (auto operandClass : classes) {
+    if (const char* name = GetOperandClassString(operandClass)) {
+      if (numPrinted) contents << ", ";
+      contents << name;
+      numPrinted++;
+    }
+  }
+
+  if (numPrinted)
+    out << "List(" << contents.str() << ")";
+  else
+    out << "EmptyList";
+}
+}  // namespace spv
+
+namespace spv {
+namespace {
+
+// Prints a listing of the operand kinds for the given instruction.
+// If the list is empty, then emit just "EmptyList",
+// otherwise the output looks like a call to the "List" macro.
+void PrintOperandClassesForInstruction(const InstructionParameters& inst,
+                                       std::ostream& out) {
+  std::vector<OperandClass> result;
+
+  const OperandParameters& operands = inst.operands;
+  for (int i = 0; i < operands.getNum(); i++) {
+    result.push_back(operands.getClass(i));
+  }
+  PrintOperandClasses(result, out);
+}
+
+// Prints the table entry for the given instruction with the given opcode.
+void PrintInstructionDesc(int opcode, const InstructionParameters& inst, std::ostream& out) {
+  const char* name = OpcodeString(opcode);
+  // There can be gaps in the listing.
+  // All valid operations have a name beginning with "Op".
+  if (strlen(name) > 2 && name[0] == 'O' && name[1] == 'p') {
+    out << "Instruction("
+        << name + 2 << ", "; // Skip the "Op" part.
+    out << (inst.hasResult() ? 1 : 0) << ", ";
+    out << (inst.hasType() ? 1 : 0) << ", ";
+    out << inst.operands.getNum() << ", ";
+
+    // Emit the capability, if any.
+    // The SPIR-V tools doesn't handle the concept of depending on more than
+    // one capability.  So call it out separately.  Currently the biggest case
+    // is 2.  This is a big hack.
+    out << inst.capabilities.size() << ", ";
+    assert(inst.capabilities.size() < 3);
+    if (inst.capabilities.size() == 1) {
+      out << "Capability(" << CapabilityString(inst.capabilities[0]) << "), ";
+    } else if (inst.capabilities.size() == 2) {
+      out << "Capability2(" << CapabilityString(inst.capabilities[0]) << ","
+          << CapabilityString(inst.capabilities[1]) << "), ";
+    } else {
+      out << "Capability(None), ";
+    }
+
+    out << (IsVariableLength(inst) ? 1 : 0) << ", ";
+    PrintOperandClassesForInstruction(inst, out);
+    out << ")" << std::endl;
+  }
+}
+
+} // anonymous namespace
+
+void PrintAssemblerTable(std::ostream& out) {
+  out << "// Instruction fields are:\n"
+      << "//    name - skips the \"Op\" prefix\n"
+      << "//    {0|1} - whether the instruction generates a result Id\n"
+      << "//    {0|1} - whether the instruction encodes the type of the result Id\n"
+      << "//    numLogicalOperands - does not include result id or type id\n"
+      << "//    numCapabilities - we only handle 0 or 1 required capabilities\n"
+      << "//    Capability(<capability-name>) - capability required to use this instruction. Might be None.\n"
+      << "//       There can be Capability2(a,b) for dependence on two capabilities.\n"
+      << "//    {0|1} - whether the instruction is variable number of words\n"
+      << "//    EmptyList or List(...) - list of classes of logical operands\n"
+      << "// Example use:\n"
+      << "// #define EmptyList {}\n"
+      << "// #define List(...) {__VA_ARGS__}\n"
+      << "// #define Capability(C) Capability##C\n"
+      << "// #define CapabilityNone -1\n"
+      << "// #define Instruction(Name,HasResult,HasType,NumLogicalOperands,CapabiltyRequired,IsVariable,LogicalArgsList)\n";
+
+  for (int i = 0; i < spv::OpcodeCeiling ; i++ ) {
+    PrintInstructionDesc(i, InstructionDesc[i], out);
+  }
+}
+
+}
diff --git a/tools/spirv/assembler_table.h b/tools/spirv/assembler_table.h
new file mode 100644
index 0000000..b98303a
--- /dev/null
+++ b/tools/spirv/assembler_table.h
@@ -0,0 +1,49 @@
+// Copyright (c) 2015 The Khronos Group Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and/or associated documentation files (the
+// "Materials"), to deal in the Materials without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Materials, and to
+// permit persons to whom the Materials are furnished to do so, subject to
+// the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Materials.
+//
+// MODIFICATIONS TO THIS FILE MAY MEAN IT NO LONGER ACCURATELY REFLECTS
+// KHRONOS STANDARDS. THE UNMODIFIED, NORMATIVE VERSIONS OF KHRONOS
+// SPECIFICATIONS AND HEADER INFORMATION ARE LOCATED AT
+//    https://www.khronos.org/registry/
+//
+// THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+// IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+// TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+// MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
+
+#pragma once
+#ifndef ASSEMBLER_TABLE_H
+#define ASSEMBLER_TABLE_H
+
+#include <iostream>
+#include <vector>
+
+#include "doc.h"
+
+namespace spv {
+
+    // Prints the tables used to define the structure of instructions.
+    // Assumes that parameterization has already occurred
+    void PrintAssemblerTable(std::ostream& out);
+
+    // Prints a listing of the operand kinds.
+    // If the list is empty, then emit just "EmptyList",
+    // otherwise the output looks like a call to the "List" macro.
+    void PrintOperandClasses(const std::vector<OperandClass>& classes, std::ostream& out);
+
+};  // end namespace spv
+
+#endif // ASSEMBLER_TABLE_H
diff --git a/tools/spirv/doc.h b/tools/spirv/doc.h
index 78b1031..a182509 100644
--- a/tools/spirv/doc.h
+++ b/tools/spirv/doc.h
@@ -32,6 +32,9 @@
 //ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 //POSSIBILITY OF SUCH DAMAGE.
 
+#ifndef DOC_H_
+#define DOC_H_
+
 //
 // Author: John Kessenich, LunarG
 //
@@ -81,6 +84,7 @@ const char* KernelEnqueueFlagsString(int);
 const char* KernelProfilingInfoString(int);
 const char* CapabilityString(int);
 const char* OpcodeString(int);
+const char* OperandClassString(int);
 
 // For grouping opcodes into subsections
 enum OpcodeClass {
@@ -159,6 +163,10 @@ enum OperandClass {
 
     OperandOpcode,
 
+    // The operand class enum is not part of the spec, so
+    // it should come after OperandOpcode.
+    OperandOperandClass,
+
     OperandCount
 };
 
@@ -257,3 +265,5 @@ const char* AccessQualifierString(int attr);
 void PrintOperands(const OperandParameters& operands, int reservedOperands);
 
 };  // end namespace spv
+
+#endif // DOC_H_
diff --git a/tools/spirv/main.cpp b/tools/spirv/main.cpp
index d7312f9..e1413bb 100644
--- a/tools/spirv/main.cpp
+++ b/tools/spirv/main.cpp
@@ -46,6 +46,7 @@ namespace spv {
 #include "headers/OpenCL.std.h"
 
 // This tool's includes
+#include "assembler_table.h"
 #include "disassemble.h"
 #include "header.h"
 #include "doc.h"
@@ -65,6 +66,8 @@ enum TOptions {
     EOptionDisassemble                = 0x004,
     EOptionPrintHeader                = 0x008,
     EOptionPrintOclBuiltinsAsciidoc   = 0x010,
+    EOptionPrintAssemblerTable        = 0x020,
+    EOptionPrintOclInstructionsTable  = 0x040,
 };
 
 std::string Filename;
@@ -86,9 +89,11 @@ void Usage()
            "  -H print header in all supported languages to files in current directory\n"
            "  -p print documentation\n"
            "  -s [version] prints the SPIR-V extended instructions documentation\n"
-           "      'CL12': OpenCL 1.2 extended instructions documentation\n"
-           "      'CL20': OpenCL 2.0 extended instructions documentation\n"
-           "      'CL21': OpenCL 2.1 extended instructions documentation\n"
+           "      'OpenCL': OpenCL 1.2, 2.0, 2.1 extended instructions documentation\n"
+           "      'GLSL': GLSL extended instructions documentation\n"
+           "  -a print table for the assembler\n"
+           "  -C print OpenCL instructions for the assembler\n"
+           "     This is incompatibile with -s OpenCL\n"
            );
 }
 
@@ -155,6 +160,12 @@ bool ProcessArguments(int argc, char* argv[])
                 }
                 return true;
             }
+            case 'a':
+                Options |= EOptionPrintAssemblerTable;
+                break;
+            case 'C':
+                Options |= EOptionPrintOclInstructionsTable;
+                break;
             default:
                 return false;
             }
@@ -162,6 +173,9 @@ bool ProcessArguments(int argc, char* argv[])
             Filename = std::string(argv[0]);
         }
     }
+    if ((Options & EOptionPrintOclBuiltinsAsciidoc) &&
+        (Options & EOptionPrintOclInstructionsTable))
+      return false;
 
     return true;
 }
@@ -220,5 +234,11 @@ int main(int argc, char* argv[])
     if (Options & EOptionPrintHeader)
         spv::PrintHeader(Language, std::cout);
 
+    if (Options & EOptionPrintAssemblerTable)
+        spv::PrintAssemblerTable(std::cout);
+
+    if (Options & EOptionPrintOclInstructionsTable)
+        spv::PrintOclInstructionsTable(std::cout);
+
     return 0;
 }