Add unit testing of fdlibm

The project is relying on a variant of fdlibm, which has aleady
been edited but never verified for correctness. This patch adds
unit testing of fdlibm by:

* introducing a test generator that uses a trusted libm
  implementation to calculate correct and expected results of math
  functions (tools/gen-test-fdlibm.c),
* adding tests created with the generator that stress all publicly
  exported functions of jerry's fdlibm
  (tests/unit/test-fdlibm.inc.h), and
* adding a unit test file to drive the generated tests
  (tests/unit/test-fdlibm.c).

Note: The test generator is not expected to be executed often, thus
it is not wired into the build system. If it gets edited, it must
be built locally and must be used to re-generate the .inc.h file.

During development, it turned out that tests/unit/test-common.h
included the system header math.h, which was only a bad smell until
now but became a real header conflict issue with the introduction
of the fdlibm unit test. Thus, this patch also changes the include
to fdlibm-math.h.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss [email protected]

Author: akosthekiss

tests/unit/test-common.h

@@ -18,7 +18,7 @@
 
 #include "jrt.h"
 
-#include <math.h>
+#include "fdlibm-math.h"
 #include <setjmp.h>
 #include <stdio.h>
 #include <stdlib.h>

tests/unit/test-fdlibm.c

@@ -0,0 +1,83 @@
+/* Copyright 2016 Samsung Electronics Co., Ltd.
+ * Copyright 2016 University of Szeged.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Unit test for fdlibm
+ */
+
+#include "test-common.h"
+
+static bool passed = true;
+
+static void
+check_int (const char *expr, int computed, int expected)
+{
+  printf ("%s = %d [expected=%d] ", expr, computed, expected);
+
+  bool result = computed == expected;
+  printf ("%s\n", result ? "PASS" : "FAIL");
+
+  passed &= result;
+} /* check_int */
+
+static void
+check_double (const char *expr, double computed, double expected)
+{
+  uint64_t *computed_bits_p = (uint64_t *) &computed;
+  uint64_t *expected_bits_p = (uint64_t *) &expected;
+
+  printf ("%s = 0x%lx [expected=0x%lx] ", expr, *computed_bits_p, *expected_bits_p);
+
+  bool result;
+  if (isnan (computed) && isnan (expected))
+  {
+    result = true;
+  }
+  else
+  {
+    int64_t diff = (int64_t) (*computed_bits_p - *expected_bits_p);
+    if (diff < 0)
+    {
+      diff = -diff;
+    }
+
+    if (diff <= 1) /* tolerate 1 bit of differene in the last place */
+    {
+      result = true;
+      if (diff != 0)
+      {
+        printf ("APPROX ");
+      }
+    }
+    else
+    {
+      result = false;
+    }
+  }
+  printf ("%s\n", result ? "PASS" : "FAIL");
+
+  passed &= result;
+} /* check_double */
+
+int
+main (int __attr_unused___ argc,
+      char __attr_unused___ **argv)
+{
+#define INF INFINITY
+#include "test-fdlibm.inc.h"
+
+  return passed ? 0 : 1;
+} /* main */