[libc] exp fuzz tests (#148086)

Created fuzz tests for exp functions

---------

Co-authored-by: Sriya Pratipati <sriyap@google.com>

libc/fuzzing/math/CMakeLists.txt

@@ -62,6 +62,42 @@ add_libc_fuzzer(
     libc.src.math.nextafterl
 )
 
+add_libc_fuzzer(
+  exp_fuzz
+  NEED_MPFR
+  SRCS
+    exp_fuzz.cpp
+  DEPENDS
+    libc.src.math.exp
+)
+
+add_libc_fuzzer(
+  exp10_fuzz
+  NEED_MPFR
+  SRCS
+    exp10_fuzz.cpp
+  DEPENDS
+    libc.src.math.exp10
+)
+
+add_libc_fuzzer(
+  exp2_fuzz
+  NEED_MPFR
+  SRCS
+    exp2_fuzz.cpp
+  DEPENDS
+    libc.src.math.exp2
+)
+
+add_libc_fuzzer(
+  expm1_fuzz
+  NEED_MPFR
+  SRCS
+    expm1_fuzz.cpp
+  DEPENDS
+    libc.src.math.expm1
+)
+
 add_libc_fuzzer(
   asin_fuzz
   NEED_MPFR

libc/fuzzing/math/exp10_fuzz.cpp

@@ -0,0 +1,38 @@
+//===-- exp10_fuzz.cpp ----------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// Fuzzing test for llvm-libc exp10 implementation.
+///
+//===----------------------------------------------------------------------===//
+
+#include "src/math/exp10.h"
+#include "utils/MPFRWrapper/mpfr_inc.h"
+#include <math.h>
+
+extern "C" int LLVMFuzzerTestOneInput(double x) {
+  // remove NaN and inf
+  if (isnan(x) || isinf(x))
+    return 0;
+  // signed zeros already tested in unit tests
+  if (signbit(x) && x == 0.0)
+    return 0;
+  mpfr_t input;
+  mpfr_init2(input, 53);
+  mpfr_set_d(input, x, MPFR_RNDN);
+  int output = mpfr_exp10(input, input, MPFR_RNDN);
+  mpfr_subnormalize(input, output, MPFR_RNDN);
+  double to_compare = mpfr_get_d(input, MPFR_RNDN);
+
+  double result = LIBC_NAMESPACE::exp10(x);
+
+  if (result != to_compare)
+    __builtin_trap();
+
+  mpfr_clear(input);
+  return 0;
+}

libc/fuzzing/math/exp2_fuzz.cpp

@@ -0,0 +1,38 @@
+//===-- exp2_fuzz.cpp -----------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// Fuzzing test for llvm-libc exp2 implementation.
+///
+//===----------------------------------------------------------------------===//
+
+#include "src/math/exp2.h"
+#include "utils/MPFRWrapper/mpfr_inc.h"
+#include <math.h>
+
+extern "C" int LLVMFuzzerTestOneInput(double x) {
+  // remove NaN and inf
+  if (isnan(x) || isinf(x))
+    return 0;
+  // signed zeros already tested in unit tests
+  if (signbit(x) && x == 0.0)
+    return 0;
+  mpfr_t input;
+  mpfr_init2(input, 53);
+  mpfr_set_d(input, x, MPFR_RNDN);
+  int output = mpfr_exp2(input, input, MPFR_RNDN);
+  mpfr_subnormalize(input, output, MPFR_RNDN);
+  double to_compare = mpfr_get_d(input, MPFR_RNDN);
+
+  double result = LIBC_NAMESPACE::exp2(x);
+
+  if (result != to_compare)
+    __builtin_trap();
+
+  mpfr_clear(input);
+  return 0;
+}

libc/fuzzing/math/exp_fuzz.cpp

@@ -0,0 +1,38 @@
+//===-- exp_fuzz.cpp ------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// Fuzzing test for llvm-libc exp implementation.
+///
+//===----------------------------------------------------------------------===//
+
+#include "src/math/exp.h"
+#include "utils/MPFRWrapper/mpfr_inc.h"
+#include <math.h>
+
+extern "C" int LLVMFuzzerTestOneInput(double x) {
+  // remove NaN and inf
+  if (isnan(x) || isinf(x))
+    return 0;
+  // signed zeros already tested in unit tests
+  if (signbit(x) && x == 0.0)
+    return 0;
+  mpfr_t input;
+  mpfr_init2(input, 53);
+  mpfr_set_d(input, x, MPFR_RNDN);
+  int output = mpfr_exp(input, input, MPFR_RNDN);
+  mpfr_subnormalize(input, output, MPFR_RNDN);
+  double to_compare = mpfr_get_d(input, MPFR_RNDN);
+
+  double result = LIBC_NAMESPACE::exp(x);
+
+  if (result != to_compare)
+    __builtin_trap();
+
+  mpfr_clear(input);
+  return 0;
+}

libc/fuzzing/math/expm1_fuzz.cpp

@@ -0,0 +1,38 @@
+//===-- expm1_fuzz.cpp ----------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// Fuzzing test for llvm-libc expm1 implementation.
+///
+//===----------------------------------------------------------------------===//
+
+#include "src/math/expm1.h"
+#include "utils/MPFRWrapper/mpfr_inc.h"
+#include <math.h>
+
+extern "C" int LLVMFuzzerTestOneInput(double x) {
+  // remove NaN and inf
+  if (isnan(x) || isinf(x))
+    return 0;
+  // signed zeros already tested in unit tests
+  if (signbit(x) && x == 0.0)
+    return 0;
+  mpfr_t input;
+  mpfr_init2(input, 53);
+  mpfr_set_d(input, x, MPFR_RNDN);
+  int output = mpfr_expm1(input, input, MPFR_RNDN);
+  mpfr_subnormalize(input, output, MPFR_RNDN);
+  double to_compare = mpfr_get_d(input, MPFR_RNDN);
+
+  double result = LIBC_NAMESPACE::expm1(x);
+
+  if (result != to_compare)
+    __builtin_trap();
+
+  mpfr_clear(input);
+  return 0;
+}