libc/fuzzing/math/tan_fuzz.cpp

   1 //===-- tan_fuzz.cpp ------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 ///
   9 /// Fuzzing test for llvm-libc tan implementation.
  10 ///
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "src/math/tan.h"
  14 #include "utils/MPFRWrapper/mpfr_inc.h"
  15 #include <math.h>
  16
  17 extern "C" int LLVMFuzzerTestOneInput(const double x) {
  18   // remove NaN and inf as preconditions
  19   if (isnan(x))
  20     return 0;
  21   if (isinf(x))
  22     return 0;
  23   // signed zeros already tested in unit tests
  24   if (signbit(x) && x == 0.0)
  25     return 0;
  26   mpfr_t input;
  27   mpfr_init2(input, 53);
  28   mpfr_set_d(input, x, MPFR_RNDN);
  29   int output = mpfr_tan(input, input, MPFR_RNDN);
  30   mpfr_subnormalize(input, output, MPFR_RNDN);
  31   double to_compare = mpfr_get_d(input, MPFR_RNDN);
  32
  33   double result = LIBC_NAMESPACE::tan(x);
  34
  35   if (result != to_compare)
  36     __builtin_trap();
  37
  38   mpfr_clear(input);
  39   return 0;
  40 }