diff --git a/renderdoc/driver/shaders/spirv/spirv_editor.h b/renderdoc/driver/shaders/spirv/spirv_editor.h
index a11bd04a9..2aec15d0b 100644
--- a/renderdoc/driver/shaders/spirv/spirv_editor.h
+++ b/renderdoc/driver/shaders/spirv/spirv_editor.h
@@ -34,6 +34,57 @@ namespace rdcspv
 {
 class Editor;
 
+struct IdOrWord
+{
+  constexpr inline IdOrWord() : value(0) {}
+  constexpr inline IdOrWord(uint32_t val) : value(val) {}
+  inline IdOrWord(Id id) : value(id.value()) {}
+  inline operator uint32_t() const { return value; }
+  constexpr inline bool operator==(const IdOrWord o) const { return value == o.value; }
+  constexpr inline bool operator!=(const IdOrWord o) const { return value != o.value; }
+  constexpr inline bool operator<(const IdOrWord o) const { return value < o.value; }
+private:
+  uint32_t value;
+};
+
+// helper in the style of the auto-generated one for GLSL ext insts
+struct OpGLSL450
+{
+  OpGLSL450(IdResultType resultType, IdResult result, Id glsl450, rdcspv::GLSLstd450 inst,
+            const rdcarray<IdOrWord> &params)
+      : op(OpCode), wordCount(MinWordSize + (uint16_t)params.size())
+  {
+    this->resultType = resultType;
+    this->result = result;
+    this->glsl450 = glsl450;
+    this->inst = inst;
+    this->params.resize(params.size());
+    for(size_t i = 0; i < params.size(); i++)
+      this->params[i] = params[i];
+  }
+
+  operator Operation() const
+  {
+    rdcarray<uint32_t> words;
+    words.push_back(resultType.value());
+    words.push_back(result.value());
+    words.push_back(glsl450.value());
+    words.push_back((uint32_t)inst);
+    words.append(params);
+    return Operation(OpCode, words);
+  }
+
+  static constexpr Op OpCode = Op::ExtInst;
+  static constexpr uint16_t MinWordSize = 4U;
+  Op op;
+  uint16_t wordCount;
+  IdResultType resultType;
+  IdResult result;
+  Id glsl450;
+  rdcspv::GLSLstd450 inst;
+  rdcarray<uint32_t> params;
+};
+
 struct OperationList : public rdcarray<Operation>
 {
   // add an operation and return its result id
diff --git a/renderdoc/driver/vulkan/vk_bindless_feedback.cpp b/renderdoc/driver/vulkan/vk_bindless_feedback.cpp
index 9ee1afd0e..a2f61d2af 100644
--- a/renderdoc/driver/vulkan/vk_bindless_feedback.cpp
+++ b/renderdoc/driver/vulkan/vk_bindless_feedback.cpp
@@ -463,12 +463,8 @@ void AnnotateShader(const SPIRVPatchData &patchData, const char *entryName,
             rdcspv::Id clampedtype =
                 editor.DeclareType(rdcspv::Scalar(rdcspv::Op::TypeInt, targetIndexWidth, false));
             index = editor.AddOperation(
-                it, rdcspv::Operation(
-                        rdcspv::Op::ExtInst,
-                        {
-                            clampedtype.value(), editor.MakeId().value(), glsl450.value(),
-                            (uint32_t)rdcspv::GLSLstd450::UMin, index.value(), maxSlotID.value(),
-                        }));
+                it, rdcspv::OpGLSL450(clampedtype, editor.MakeId(), glsl450,
+                                      rdcspv::GLSLstd450::UMin, {index, maxSlotID}));
             it++;
           }
 
diff --git a/renderdoc/driver/vulkan/vk_postvs.cpp b/renderdoc/driver/vulkan/vk_postvs.cpp
index 20d64d220..27e1ef7d3 100644
--- a/renderdoc/driver/vulkan/vk_postvs.cpp
+++ b/renderdoc/driver/vulkan/vk_postvs.cpp
@@ -1055,12 +1055,9 @@ static void ConvertToMeshOutputCompute(const ShaderReflection &refl, const SPIRV
               editor.SetName(packed, StringFormat::Fmt("packed_%c", swizzle[c]));
 
               // double comp = PackDouble2x32(packed);
-              comps[c] = ops.add(rdcspv::Operation(
-                  rdcspv::Op::ExtInst,
-                  {
-                      editor.DeclareType(rdcspv::scalar<double>()).value(), editor.MakeId().value(),
-                      glsl450.value(), (uint32_t)rdcspv::GLSLstd450::PackDouble2x32, packed.value(),
-                  }));
+              comps[c] = ops.add(rdcspv::OpGLSL450(editor.DeclareType(rdcspv::scalar<double>()),
+                                                   editor.MakeId(), glsl450,
+                                                   rdcspv::GLSLstd450::PackDouble2x32, {packed}));
             }
 
             // if there's only one component it's ready, otherwise construct a vector
diff --git a/renderdoc/driver/vulkan/vk_shaderdebug.cpp b/renderdoc/driver/vulkan/vk_shaderdebug.cpp
index 28a070bff..648eabd16 100644
--- a/renderdoc/driver/vulkan/vk_shaderdebug.cpp
+++ b/renderdoc/driver/vulkan/vk_shaderdebug.cpp
@@ -623,11 +623,8 @@ static void CreatePSInputFetcher(rdcarray<uint32_t> &fragspv, uint32_t &structSt
           ops.add(rdcspv::OpFSub(float2Type, editor.MakeId(), fragXY, destXY));
 
       // abs()
-      rdcspv::Id fragXYAbs = ops.add(rdcspv::Operation(
-          rdcspv::Op::ExtInst, {
-                                   float2Type.value(), editor.MakeId().value(), glsl450.value(),
-                                   (uint32_t)rdcspv::GLSLstd450::FAbs, fragXYRelative.value(),
-                               }));
+      rdcspv::Id fragXYAbs = ops.add(rdcspv::OpGLSL450(float2Type, editor.MakeId(), glsl450,
+                                                       rdcspv::GLSLstd450::FAbs, {fragXYRelative}));
 
       rdcspv::Id half = editor.AddConstantImmediate<float>(0.5f);
       rdcspv::Id threshold =