+/*-------------------------------------------------------------------------
+ * drawElements Base Portability Library
+ * -------------------------------------
+ *
+ * Copyright 2015 The Android Open Source Project
+ *
+ * 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.
+ *
+ *//*!
+ * \file
+ * \brief Testing of deMath functions.
+ *//*--------------------------------------------------------------------*/
+
+#include "deMath.h"
+#include "deRandom.h"
+
+DE_BEGIN_EXTERN_C
+
+static deBool conversionToFloatLosesPrecision (deInt32 x)
+{
+ if (x == -0x7FFFFFFF - 1)
+ return DE_FALSE;
+ else if (x < 0)
+ return conversionToFloatLosesPrecision(-x);
+ else if (x == 0)
+ return DE_FALSE;
+ else if (((deUint32)x & 0x1) == 0)
+ return conversionToFloatLosesPrecision(x >> 1); /* remove trailing zeros */
+ else
+ return x > ((1 << 24) - 1); /* remaining part does not fit in the mantissa? */
+}
+
+static void testSingleInt32ToFloat (deInt32 x)
+{
+ /* roundTowardsToNegInf(x) <= round(x) <= roundTowardsPosInf(x). */
+ /* \note: Need to use inequalities since round(x) returns arbitrary precision floats. */
+ DE_TEST_ASSERT(deInt32ToFloatRoundToNegInf(x) <= deInt32ToFloat(x));
+ DE_TEST_ASSERT(deInt32ToFloat(x) <= deInt32ToFloatRoundToPosInf(x));
+
+ /* if precision is lost, floor(x) < ceil(x). Else floor(x) == ceil(x) */
+ if (conversionToFloatLosesPrecision(x))
+ DE_TEST_ASSERT(deInt32ToFloatRoundToNegInf(x) < deInt32ToFloatRoundToPosInf(x));
+ else
+ DE_TEST_ASSERT(deInt32ToFloatRoundToNegInf(x) == deInt32ToFloatRoundToPosInf(x));
+
+ /* max one ulp from each other */
+ if (deInt32ToFloatRoundToNegInf(x) < deInt32ToFloatRoundToPosInf(x))
+ {
+ union
+ {
+ float f;
+ deInt32 u;
+ } v0, v1;
+
+ v0.f = deInt32ToFloatRoundToNegInf(x);
+ v1.f = deInt32ToFloatRoundToPosInf(x);
+
+ DE_TEST_ASSERT(v0.u + 1 == v1.u || v0.u == v1.u + 1);
+ }
+}
+
+static void testInt32ToFloat (void)
+{
+ const int numIterations = 2500000;
+
+ int sign;
+ int numBits;
+ int delta;
+ int ndx;
+ deRandom rnd;
+
+ deRandom_init(&rnd, 0xdeadbeefu-1);
+
+ for (sign = -1; sign < 1; ++sign)
+ for (numBits = 0; numBits < 32; ++numBits)
+ for (delta = -2; delta < 3; ++delta)
+ {
+ const deInt64 x = (deInt64)(sign == -1 ? (-1) : (+1)) * (1LL << (deInt64)numBits) + (deInt64)delta;
+
+ /* would overflow */
+ if (x > 0x7FFFFFFF || x < -0x7FFFFFFF - 1)
+ continue;
+
+ testSingleInt32ToFloat((deInt32)x);
+ }
+
+ for (ndx = 0; ndx < numIterations; ++ndx)
+ testSingleInt32ToFloat((deInt32)deRandom_getUint32(&rnd));
+}
+
+void deMath_selfTest (void)
+{
+ /* Test Int32ToFloat*(). */
+ testInt32ToFloat();
+}
+
+DE_END_EXTERN_C