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.sh and tools/unit-tests/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 used locally 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 */