From e3076d26ccb2bbe0869011d7f0664281f581d1e9 Mon Sep 17 00:00:00 2001
From: Cedric Nugteren <web@cedricnugteren.nl>
Date: Tue, 27 Sep 2016 19:42:58 +0200
Subject: [PATCH] Added more relaxed error checking for the half-precision
 tests

---
 CHANGELOG                   |  1 +
 test/correctness/tester.cpp | 26 +++++++++++++++++---------
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 0c181f2b..4d8c6612 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -2,6 +2,7 @@
 Development version (next release)
 - It is now possible to set OpenCL compiler options through the env variable CLBLAST_BUILD_OPTIONS
 - Fixed a bug in the tests and samples related to waiting for an invalid event
+- Various minor fixes and enhancements
 
 Version 0.9.0
 - Updated to version 6.0 of the CLCudaAPI C++11 OpenCL header
diff --git a/test/correctness/tester.cpp b/test/correctness/tester.cpp
index 362c5c2c..41e457b6 100644
--- a/test/correctness/tester.cpp
+++ b/test/correctness/tester.cpp
@@ -358,28 +358,33 @@ void Tester<T,U>::PrintErrorLog(const std::vector<ErrorLogEntry> &error_log) {
 // Compares two floating point values and returns whether they are within an acceptable error
 // margin. This replaces GTest's EXPECT_NEAR().
 template <typename T>
-bool TestSimilarity(const T val1, const T val2) {
+bool TestSimilarityNear(const T val1, const T val2,
+                        const T error_margin_absolute, const T error_margin_relative) {
   const auto difference = std::fabs(val1 - val2);
 
-  // Set the allowed error margin for floating-point comparisons
-  constexpr auto kErrorMarginRelative = T(0.025);
-  constexpr auto kErrorMarginAbsolute = T(1.0e-3);
-
   // Shortcut, handles infinities
   if (val1 == val2) {
     return true;
   }
   // The values are zero or very small: the relative error is less meaningful
-  else if (val1 == 0 || val2 == 0 || difference < kErrorMarginAbsolute) {
-    return (difference < kErrorMarginAbsolute);
+  else if (val1 == 0 || val2 == 0 || difference < error_margin_absolute) {
+    return (difference < error_margin_absolute);
   }
   // Use relative error
   else {
     const auto absolute_sum = std::fabs(val1) + std::fabs(val2);
-    return (difference / absolute_sum) < kErrorMarginRelative;
+    return (difference / absolute_sum) < error_margin_relative;
   }
 }
 
+// Default method for similarity testing
+template <typename T>
+bool TestSimilarity(const T val1, const T val2) {
+  constexpr auto kErrorMarginRelative = T(0.025);
+  constexpr auto kErrorMarginAbsolute = T(0.001);
+  return TestSimilarityNear(val1, val2, kErrorMarginRelative, kErrorMarginAbsolute);
+}
+
 // Compiles the default case for standard data-types
 template bool TestSimilarity<float>(const float, const float);
 template bool TestSimilarity<double>(const double, const double);
@@ -399,7 +404,10 @@ bool TestSimilarity(const double2 val1, const double2 val2) {
 }
 template <>
 bool TestSimilarity(const half val1, const half val2) {
-  return TestSimilarity(HalfToFloat(val1), HalfToFloat(val2));
+  constexpr auto kErrorMarginRelative = float(0.050);
+  constexpr auto kErrorMarginAbsolute = float(0.002);
+  return TestSimilarityNear(HalfToFloat(val1), HalfToFloat(val2),
+                            kErrorMarginRelative, kErrorMarginAbsolute);
 }
 
 // =================================================================================================