spv.no_input_attachment_index.frag
// Module Version 10000
// Generated by (magic number): 8000b
// Id's are bound by 19

                              Capability Shader
                              Capability InputAttachment
               1:             ExtInstImport  "GLSL.std.450"
                              MemoryModel Logical GLSL450
                              EntryPoint Fragment 4  "main" 9
                              ExecutionMode 4 OriginUpperLeft
                              Source GLSL 460
                              SourceExtension  "GL_EXT_optional_input_attachment_index"
                              Name 4  "main"
                              Name 9  "outColor"
                              Name 12  "ia"
                              Decorate 9(outColor) Location 0
                              Decorate 12(ia) Binding 0
                              Decorate 12(ia) DescriptorSet 0
               2:             TypeVoid
               3:             TypeFunction 2
               6:             TypeFloat 32
               7:             TypeVector 6(float) 4
               8:             TypePointer Output 7(fvec4)
     9(outColor):      8(ptr) Variable Output
              10:             TypeImage 6(float) SubpassData nonsampled format:Unknown
              11:             TypePointer UniformConstant 10
          12(ia):     11(ptr) Variable UniformConstant
              14:             TypeInt 32 1
              15:     14(int) Constant 0
              16:             TypeVector 14(int) 2
              17:   16(ivec2) ConstantComposite 15 15
         4(main):           2 Function None 3
               5:             Label
              13:          10 Load 12(ia)
              18:    7(fvec4) ImageRead 13 17
                              Store 9(outColor) 18
                              Return
                              FunctionEnd