SKIP: FAILED

; SPIR-V
; Version: 1.3
; Generator: Google Tint Compiler; 0
; Bound: 22
; Schema: 0
               OpCapability Shader
               OpMemoryModel Logical GLSL450
               OpEntryPoint Vertex %vertex_main "vertex_main" %tint_pointsize
               OpEntryPoint Fragment %fragment_main "fragment_main"
               OpEntryPoint GLCompute %compute_main "compute_main"
               OpExecutionMode %fragment_main OriginUpperLeft
               OpExecutionMode %compute_main LocalSize 1 1 1
               OpName %tint_pointsize "tint_pointsize"
               OpName %fwidth_df38ef "fwidth_df38ef"
               OpName %res "res"
               OpName %vertex_main "vertex_main"
               OpName %fragment_main "fragment_main"
               OpName %compute_main "compute_main"
               OpDecorate %tint_pointsize BuiltIn PointSize
      %float = OpTypeFloat 32
%_ptr_Output_float = OpTypePointer Output %float
          %4 = OpConstantNull %float
%tint_pointsize = OpVariable %_ptr_Output_float Output %4
       %void = OpTypeVoid
          %5 = OpTypeFunction %void
    %float_1 = OpConstant %float 1
%_ptr_Function_float = OpTypePointer Function %float
%fwidth_df38ef = OpFunction %void None %5
          %8 = OpLabel
        %res = OpVariable %_ptr_Function_float Function %4
          %9 = OpFwidth %float %float_1
               OpStore %res %9
               OpReturn
               OpFunctionEnd
%vertex_main = OpFunction %void None %5
         %14 = OpLabel
               OpStore %tint_pointsize %float_1
         %15 = OpFunctionCall %void %fwidth_df38ef
               OpReturn
               OpFunctionEnd
%fragment_main = OpFunction %void None %5
         %17 = OpLabel
         %18 = OpFunctionCall %void %fwidth_df38ef
               OpReturn
               OpFunctionEnd
%compute_main = OpFunction %void None %5
         %20 = OpLabel
         %21 = OpFunctionCall %void %fwidth_df38ef
               OpReturn
               OpFunctionEnd


Validation Failure:
1:1: OpEntryPoint Entry Point <id> '13[%vertex_main]'s callgraph contains function <id> 7[%fwidth_df38ef], which cannot be used with the current execution model:
Derivative instructions require Fragment or GLCompute execution model: Fwidth

  %fwidth_df38ef = OpFunction %void None %5