1 /*------------------------------------------------------------------------- 2 * drawElements Base Portability Library 3 * ------------------------------------- 4 * 5 * Copyright 2015 The Android Open Source Project 6 * 7 * Licensed under the Apache License, Version 2.0 (the "License"); 8 * you may not use this file except in compliance with the License. 9 * You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, software 14 * distributed under the License is distributed on an "AS IS" BASIS, 15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 * See the License for the specific language governing permissions and 17 * limitations under the License. 18 * 19 *//*! 20 * \file 21 * \brief Testing of deMath functions. 22 *//*--------------------------------------------------------------------*/ 23 24 #include "deMath.h" 25 #include "deRandom.h" 26 27 DE_BEGIN_EXTERN_C 28 conversionToFloatLosesPrecision(int32_t x)29static bool conversionToFloatLosesPrecision(int32_t x) 30 { 31 if (x == -0x7FFFFFFF - 1) 32 return false; 33 else if (x < 0) 34 return conversionToFloatLosesPrecision(-x); 35 else if (x == 0) 36 return false; 37 else if (((uint32_t)x & 0x1) == 0) 38 return conversionToFloatLosesPrecision(x >> 1); /* remove trailing zeros */ 39 else 40 return x > ((1 << 24) - 1); /* remaining part does not fit in the mantissa? */ 41 } 42 testSingleInt32ToFloat(int32_t x)43static void testSingleInt32ToFloat(int32_t x) 44 { 45 /* roundTowardsToNegInf(x) <= round(x) <= roundTowardsPosInf(x). */ 46 /* \note: Need to use inequalities since round(x) returns arbitrary precision floats. */ 47 DE_TEST_ASSERT(deInt32ToFloatRoundToNegInf(x) <= deInt32ToFloat(x)); 48 DE_TEST_ASSERT(deInt32ToFloat(x) <= deInt32ToFloatRoundToPosInf(x)); 49 50 /* if precision is lost, floor(x) < ceil(x). Else floor(x) == ceil(x) */ 51 if (conversionToFloatLosesPrecision(x)) 52 DE_TEST_ASSERT(deInt32ToFloatRoundToNegInf(x) < deInt32ToFloatRoundToPosInf(x)); 53 else 54 DE_TEST_ASSERT(deInt32ToFloatRoundToNegInf(x) == deInt32ToFloatRoundToPosInf(x)); 55 56 /* max one ulp from each other */ 57 if (deInt32ToFloatRoundToNegInf(x) < deInt32ToFloatRoundToPosInf(x)) 58 { 59 union 60 { 61 float f; 62 int32_t u; 63 } v0, v1; 64 65 v0.f = deInt32ToFloatRoundToNegInf(x); 66 v1.f = deInt32ToFloatRoundToPosInf(x); 67 68 DE_TEST_ASSERT(v0.u + 1 == v1.u || v0.u == v1.u + 1); 69 } 70 } 71 testInt32ToFloat(void)72static void testInt32ToFloat(void) 73 { 74 const int numIterations = 2500000; 75 76 int sign; 77 int numBits; 78 int delta; 79 int ndx; 80 deRandom rnd; 81 82 deRandom_init(&rnd, 0xdeadbeefu - 1); 83 84 for (sign = -1; sign < 1; ++sign) 85 for (numBits = 0; numBits < 32; ++numBits) 86 for (delta = -2; delta < 3; ++delta) 87 { 88 const int64_t x = (int64_t)(sign == -1 ? (-1) : (+1)) * (1LL << (int64_t)numBits) + (int64_t)delta; 89 90 /* would overflow */ 91 if (x > 0x7FFFFFFF || x < -0x7FFFFFFF - 1) 92 continue; 93 94 testSingleInt32ToFloat((int32_t)x); 95 } 96 97 for (ndx = 0; ndx < numIterations; ++ndx) 98 testSingleInt32ToFloat((int32_t)deRandom_getUint32(&rnd)); 99 } 100 deMath_selfTest(void)101void deMath_selfTest(void) 102 { 103 /* Test Int32ToFloat*(). */ 104 testInt32ToFloat(); 105 } 106 107 DE_END_EXTERN_C 108