32 instructions

store_src_rg                   v0..1 = src.rg
init_lane_masks                CondMask = LoopMask = RetMask = true
copy_constant                  ok = 0xFFFFFFFF
copy_uniform                   $0 = colorGreen(0)
cast_to_uint_from_float        $0 = FloatToUint($0)
copy_slot_unmasked             val = $0
copy_slot_unmasked             $1 = val
bitwise_xor_imm_int            $1 ^= 0xFFFFFFFF
copy_2_slots_unmasked          mask = $0..1
bitwise_xor_imm_int            $0 ^= 0xFFFFFFFF
bitwise_xor_imm_int            $1 ^= 0xFFFFFFFF
copy_2_slots_unmasked          imask = $0..1
copy_2_slots_unmasked          $0..1 = mask
bitwise_xor_imm_int            $0 ^= 0xFFFFFFFF
bitwise_xor_imm_int            $1 ^= 0xFFFFFFFF
copy_2_slots_unmasked          $2..3 = imask
bitwise_xor_imm_int            $2 ^= 0xFFFFFFFF
bitwise_xor_imm_int            $3 ^= 0xFFFFFFFF
bitwise_and_2_ints             $0..1 &= $2..3
copy_2_slots_unmasked          mask = $0..1
copy_slot_unmasked             $0 = ok
copy_2_slots_unmasked          $1..2 = mask
cmpeq_imm_int                  $1 = equal($1, 0)
cmpeq_imm_int                  $2 = equal($2, 0)
bitwise_and_int                $1 &= $2
bitwise_and_int                $0 &= $1
copy_slot_unmasked             ok = $0
swizzle_4                      $0..3 = ($0..3).xxxx
copy_4_uniforms                $4..7 = colorRed
copy_4_uniforms                $8..11 = colorGreen
mix_4_ints                     $0..3 = mix($4..7, $8..11, $0..3)
load_src                       src.rgba = $0..3