Disabled external gits

cs440-acg/ext/openexr/IlmBase/HalfTest/testError.cpp

@@ -0,0 +1,212 @@
+#include <testError.h>
+#include "half.h"
+#include <iostream>
+#include <stdlib.h>
+#include <assert.h>
+
+
+using namespace std;
+
+namespace {
+
+float
+drand()
+{
+    return static_cast<float> (rand()/(RAND_MAX+1.0f));
+}
+
+} // namespace
+
+
+void
+testNormalizedConversionError()
+{
+    cout << "float-to-half conversion error for normalized half numbers\n";
+
+    float eMax = 0;
+
+    for (int i = 0; i < 20000000; i++)
+    {
+	float f (drand() * HALF_MAX);
+
+	if (f < HALF_NRM_MIN)
+	    continue;
+
+	if (i & 1)
+	    f = -f;
+
+	half h (f);
+	float e = 1.0f - h/f;
+
+	if (e < 0)
+	    e = -e;
+
+	if (e > HALF_EPSILON * 0.5)
+	{
+	    cout << "float = " << f <<
+		    ", half = " << h <<
+		    ", error = " << e << endl;
+
+	    assert (false);
+	}
+
+	if (e > eMax)
+	    eMax = e;
+    }
+
+    cout << "max error          = " << eMax << endl;
+    cout << "max expected error = " << HALF_EPSILON * 0.5 << endl;
+    cout << "ok\n\n" << flush;
+}
+
+
+void
+testDenormalizedConversionError()
+{
+    cout << "float-to-half conversion error for denormalized half numbers\n";
+
+    float eMax = 0;
+
+    for (int i = 0; i < 20000000; i++)
+    {
+	float f (drand() * (HALF_NRM_MIN - HALF_MIN));
+
+	if (i & 1)
+	    f = -f;
+
+	half h (f);
+	float e = h - f;
+
+	if (e < 0)
+	    e = -e;
+
+	if (e > HALF_MIN * 0.5)
+	{
+	    cout << "float = " << f <<
+		    ", half = " << h <<
+		    ", error = " << e << endl;
+
+	    assert (false);
+	}
+
+	if (e > eMax)
+	    eMax = e;
+    }
+
+    cout << "max error          = " << eMax << endl;
+    cout << "max expected error = " << HALF_MIN * 0.5 << endl;
+    cout << "ok\n\n" << flush;
+}
+
+
+namespace {
+
+void
+testNormalizedRounding (int n)
+{
+    cout << "rounding normalized numbers to " << n << "-bit precision\n";
+
+    float eExpected = (n < 10)? HALF_EPSILON * 0.5f * (1 << (10 - n)): 0;
+    float eMax = 0;
+
+    for (int i = 0; i < 200000; i++)
+    {
+	half h (drand() * HALF_MAX);
+
+	if (h < HALF_NRM_MIN)
+	    continue;
+
+	if (i & 1)
+	    h = -h;
+
+	half r (h.round(n));
+	float e = 1.0f - r/h;
+
+	if (e < 0)
+	    e = -e;
+
+	if (e > eExpected)
+	{
+	    cout << "half = " << h <<
+		    ", rounded = " << r <<
+		    ", error = " << e <<
+		    ", expected error = " << eExpected << endl;
+
+	    printBits (cout, h);
+	    cout << endl;
+	    printBits (cout, r);
+	    cout << endl;
+
+	    assert (false);
+	}
+
+	if (e > eMax)
+	    eMax = e;
+    }
+
+    cout << "max error          = " << eMax << endl;
+    cout << "max expected error = " << eExpected << endl;
+    cout << "ok\n\n" << flush;
+}
+
+
+void
+testDenormalizedRounding (int n)
+{
+    cout << "rounding denormalized numbers to " << n << "-bit precision\n";
+
+    float eExpected = (n < 10)? HALF_MIN * 0.5f * (1 << (10 - n)): 0;
+    float eMax = 0;
+
+    for (int i = 0; i < 200000; i++)
+    {
+	half h (drand() * (HALF_NRM_MIN - HALF_MIN));
+
+	if (i & 1)
+	    h = -h;
+
+	half r (h.round(n));
+	float e = r - h;
+
+	if (e < 0)
+	    e = -e;
+
+	if (e > eExpected)
+	{
+	    cout << "half = " << h <<
+		    ", rounded = " << r <<
+		    ", error = " << e <<
+		    ", expected error = " << eExpected << endl;
+
+	    printBits (cout, h);
+	    cout << endl;
+	    printBits (cout, r);
+	    cout << endl;
+
+	    assert (false);
+	}
+
+	if (e > eMax)
+	    eMax = e;
+    }
+
+    cout << "max error          = " << eMax << endl;
+    cout << "max expected error = " << eExpected << endl;
+    cout << "ok\n\n" << flush;
+}
+
+} // namespace
+
+
+void
+testRoundingError ()
+{
+    testNormalizedRounding (10);
+    testDenormalizedRounding (10);
+    testNormalizedRounding (9);
+    testDenormalizedRounding (9);
+    testNormalizedRounding (1);
+    testDenormalizedRounding (1);
+    testNormalizedRounding (0);
+    testDenormalizedRounding (0);
+}