3 files changed, 10 insertions, 14 deletions
diff --git a/reference_model/src/verify/verify_abs_error.cc b/reference_model/src/verify/verify_abs_error.cc
index 1afa7fd..b43da08 100644
--- a/reference_model/src/verify/verify_abs_error.cc
+++ b/reference_model/src/verify/verify_abs_error.cc
@@ -32,7 +32,7 @@ bool validateData(const double* ref, const double* bnd, const float* imp, const
 
     for (size_t i = 0; i < T; ++i)
     {
-        double errBound = ref[i] * exp2(-AccPrecision<float>::normal_frac) * bnd[i];
+        double errBound = std::abs(ref[i]) * exp2(-AccPrecision<float>::normal_frac) * bnd[i];
         bool valid      = tosaCheckFloatBound(imp[i], ref[i], errBound);
         if (!valid)
         {
diff --git a/reference_model/src/verify/verify_ulp.cc b/reference_model/src/verify/verify_ulp.cc
index b333810..6e78b96 100644
--- a/reference_model/src/verify/verify_ulp.cc
+++ b/reference_model/src/verify/verify_ulp.cc
@@ -30,15 +30,8 @@ bool tosaCheckULP(float testValue, double referenceValue, double ulpNum)
     double errorBound = 0.0;
     if (std::isfinite(referenceValue) && std::abs(referenceValue) != 0.0)
     {
-        // Make the sign of the reference value positive
-        // and adjust the test value appropriately.
-        if (referenceValue < 0)
-        {
-            referenceValue = -referenceValue;
-            testValue      = -testValue;
-        }
         // Find the exponent of the reference value.
-        int32_t referenceExponent = ilog2(referenceValue);
+        int32_t referenceExponent = ilog2(std::abs(referenceValue));
 
         // Work out the values magnitude - by raising 2 to the power of the
         // exponent and taking the normalized minimum for denormal values
diff --git a/reference_model/src/verify/verify_utils.cc b/reference_model/src/verify/verify_utils.cc
index 414f7d7..9aa6ba2 100644
--- a/reference_model/src/verify/verify_utils.cc
+++ b/reference_model/src/verify/verify_utils.cc
@@ -170,7 +170,11 @@ DType mapToDType(tosa_datatype_t dataType)
 // Like const_exp2 but for use during runtime
 double exp2(int32_t n)
 {
-    TOSA_REF_REQUIRE(-1022 <= n && n <= 1023, " Invalid exponent value (%d) in exp2", n);
+    if (n < -1075)
+    {
+        return 0.0;    // smaller than smallest denormal
+    }
+    TOSA_REF_REQUIRE(n <= 1023, " Invalid exponent value (%d) in exp2", n);
     return const_exp2(n);
 }
 
@@ -212,6 +216,9 @@ bool tosaCheckFloatBound(float testValue, double referenceValue, double errorBou
         return false;
     }
 
+    // Check the errorBound
+    TOSA_REF_REQUIRE(errorBound >= 0.f, " Invalid error bound (%g)", errorBound);
+
     // Make the sign of the reference value positive
     // and adjust the test value appropriately.
     if (referenceValue < 0)
@@ -219,10 +226,6 @@ bool tosaCheckFloatBound(float testValue, double referenceValue, double errorBou
         referenceValue = -referenceValue;
         testValue      = -testValue;
     }
-    if (errorBound < 0)
-    {
-        errorBound = -errorBound;
-    }
 
     // At this point we are ready to calculate the ULP bounds for the reference value.
     double referenceMin, referenceMax;