<dawn>/test/tint/diagnostic_filtering/for_loop_attribute.wgsl:5:21 warning: 'dpdx' must only be called from uniform control flow
  for (; x > v.x && dpdx(1.0) > 0.0; ) {
                    ^^^^^^^^^

<dawn>/test/tint/diagnostic_filtering/for_loop_attribute.wgsl:5:3 note: control flow depends on possibly non-uniform value
  for (; x > v.x && dpdx(1.0) > 0.0; ) {
  ^^^

<dawn>/test/tint/diagnostic_filtering/for_loop_attribute.wgsl:5:21 note: return value of 'dpdx' may be non-uniform
  for (; x > v.x && dpdx(1.0) > 0.0; ) {
                    ^^^^^^^^^

; SPIR-V
; Version: 1.3
; Generator: Google Tint Compiler; 0
; Bound: 43
; Schema: 0
               OpCapability Shader
               OpMemoryModel Logical GLSL450
               OpEntryPoint Fragment %main "main" %x_1
               OpExecutionMode %main OriginUpperLeft
               OpName %x_1 "x_1"
               OpName %main_inner "main_inner"
               OpName %x "x"
               OpName %v "v"
               OpName %tint_symbol "tint_symbol"
               OpName %main "main"
               OpDecorate %x_1 Location 0
      %float = OpTypeFloat 32
%_ptr_Input_float = OpTypePointer Input %float
        %x_1 = OpVariable %_ptr_Input_float Input
       %void = OpTypeVoid
          %4 = OpTypeFunction %void %float
    %v4float = OpTypeVector %float 4
         %10 = OpConstantNull %v4float
%_ptr_Function_v4float = OpTypePointer Function %v4float
       %uint = OpTypeInt 32 0
     %uint_0 = OpConstant %uint 0
%_ptr_Function_float = OpTypePointer Function %float
       %bool = OpTypeBool
%_ptr_Function_bool = OpTypePointer Function %bool
         %26 = OpConstantNull %bool
    %float_1 = OpConstant %float 1
         %32 = OpConstantNull %float
         %38 = OpTypeFunction %void
 %main_inner = OpFunction %void None %4
          %x = OpFunctionParameter %float
          %8 = OpLabel
          %v = OpVariable %_ptr_Function_v4float Function %10
%tint_symbol = OpVariable %_ptr_Function_bool Function %26
               OpStore %v %10
               OpBranch %13
         %13 = OpLabel
               OpLoopMerge %14 %15 None
               OpBranch %16
         %16 = OpLabel
         %20 = OpAccessChain %_ptr_Function_float %v %uint_0
         %21 = OpLoad %float %20
         %22 = OpFOrdGreaterThan %bool %x %21
               OpStore %tint_symbol %22
         %27 = OpLoad %bool %tint_symbol
               OpSelectionMerge %28 None
               OpBranchConditional %27 %29 %28
         %29 = OpLabel
         %30 = OpDPdx %float %float_1
         %33 = OpFOrdGreaterThan %bool %30 %32
               OpStore %tint_symbol %33
               OpBranch %28
         %28 = OpLabel
         %35 = OpLoad %bool %tint_symbol
         %34 = OpLogicalNot %bool %35
               OpSelectionMerge %36 None
               OpBranchConditional %34 %37 %36
         %37 = OpLabel
               OpBranch %14
         %36 = OpLabel
               OpBranch %15
         %15 = OpLabel
               OpBranch %13
         %14 = OpLabel
               OpReturn
               OpFunctionEnd
       %main = OpFunction %void None %38
         %40 = OpLabel
         %42 = OpLoad %float %x_1
         %41 = OpFunctionCall %void %main_inner %42
               OpReturn
               OpFunctionEnd