QtTestLib: unify handling of float and double using suitable templates

The QTest::qCompare() implementations were almost duplicates; pull the
common code out into a templated version.  Tweaked the
QTest::toString() specialization for float and double (a macro) and
fixed a bous modifier in double's format.

The doubleComparisons and floatComparisons tests in the tst_float.cpp
selftest shared a large block of tests in common, aside from the
difference of type.  Break this out into a templated static function
to save duplication.

This prepares the way for using the same templated code for qfloat16.

Change-Id: I2823fd006910c5ff88335d625d1fa05cb7753513
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 20 insertions, 22 deletions

diff --git a/src/testlib/qtestcase.cpp b/src/testlib/qtestcase.cpp
index 3ee8094ddf..0911c64e57 100644
--- a/src/testlib/qtestcase.cpp
+++ b/src/testlib/qtestcase.cpp
@@ -2485,6 +2485,20 @@ bool QTest::compare_helper(bool success, const char *failureMsg,
     return QTestResult::compare(success, failureMsg, val1, val2, actual, expected, file, line);
 }
 
+template <typename T>
+static bool floatingCompare(const T &t1, const T &t2)
+{
+    switch (std::fpclassify(t1))
+    {
+    case FP_INFINITE:
+        return (t1 < 0) == (t2 < 0) && std::fpclassify(t2) == FP_INFINITE;
+    case FP_NAN:
+        return std::fpclassify(t2) == FP_NAN;
+    default:
+        return qFuzzyCompare(t1, t2);
+    }
+}
+
 /*! \fn bool QTest::qCompare(const qfloat16 &t1, const qfloat16 &t2, const char *actual, const char *expected, const char *file, int line)
     \internal
  */
@@ -2501,16 +2515,8 @@ bool QTest::qCompare(qfloat16 const &t1, qfloat16 const &t2, const char *actual,
 bool QTest::qCompare(float const &t1, float const &t2, const char *actual, const char *expected,
                     const char *file, int line)
 {
-    bool equal = false;
-    int cl1 = std::fpclassify(t1);
-    int cl2 = std::fpclassify(t2);
-    if (cl1 == FP_INFINITE)
-        equal = ((t1 < 0) == (t2 < 0)) && cl2 == FP_INFINITE;
-    else if (cl1 == FP_NAN)
-        equal = (cl2 == FP_NAN);
-    else
-        equal = qFuzzyCompare(t1, t2);
-    return compare_helper(equal, "Compared floats are not the same (fuzzy compare)",
+    return compare_helper(floatingCompare(t1, t2),
+                          "Compared floats are not the same (fuzzy compare)",
                           toString(t1), toString(t2), actual, expected, file, line);
 }
 
@@ -2520,16 +2526,8 @@ bool QTest::qCompare(float const &t1, float const &t2, const char *actual, const
 bool QTest::qCompare(double const &t1, double const &t2, const char *actual, const char *expected,
                     const char *file, int line)
 {
-    bool equal = false;
-    int cl1 = std::fpclassify(t1);
-    int cl2 = std::fpclassify(t2);
-    if (cl1 == FP_INFINITE)
-        equal = ((t1 < 0) == (t2 < 0)) && cl2 == FP_INFINITE;
-    else if (cl1 == FP_NAN)
-        equal = (cl2 == FP_NAN);
-    else
-        equal = qFuzzyCompare(t1, t2);
-    return compare_helper(equal, "Compared doubles are not the same (fuzzy compare)",
+    return compare_helper(floatingCompare(t1, t2),
+                          "Compared doubles are not the same (fuzzy compare)",
                           toString(t1), toString(t2), actual, expected, file, line);
 }
 
@@ -2607,7 +2605,7 @@ template <> Q_TESTLIB_EXPORT char *QTest::toString<TYPE>(const TYPE &t) \
         qstrncpy(msg, "nan", 128); \
         break; \
     default: \
-        qsnprintf(msg, 128, #FORMAT, t); \
+        qsnprintf(msg, 128, #FORMAT, double(t));    \
         massageExponent(msg); \
         break; \
     } \
@@ -2615,7 +2613,7 @@ template <> Q_TESTLIB_EXPORT char *QTest::toString<TYPE>(const TYPE &t) \
 }
 
 TO_STRING_FLOAT(float, %g)
-TO_STRING_FLOAT(double, %.12lg)
+TO_STRING_FLOAT(double, %.12g)
 
 template <> Q_TESTLIB_EXPORT char *QTest::toString<qfloat16>(const qfloat16 &t)
 {