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      1 /*
      2  * Copyright 2011 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #include "SkColorData.h"
      9 #include "SkEndian.h"
     10 #include "SkFDot6.h"
     11 #include "SkFixed.h"
     12 #include "SkHalf.h"
     13 #include "SkMathPriv.h"
     14 #include "SkPoint.h"
     15 #include "SkRandom.h"
     16 #include "Test.h"
     17 
     18 static void test_clz(skiatest::Reporter* reporter) {
     19     REPORTER_ASSERT(reporter, 32 == SkCLZ(0));
     20     REPORTER_ASSERT(reporter, 31 == SkCLZ(1));
     21     REPORTER_ASSERT(reporter, 1 == SkCLZ(1 << 30));
     22     REPORTER_ASSERT(reporter, 0 == SkCLZ(~0U));
     23 
     24     SkRandom rand;
     25     for (int i = 0; i < 1000; ++i) {
     26         uint32_t mask = rand.nextU();
     27         // need to get some zeros for testing, but in some obscure way so the
     28         // compiler won't "see" that, and work-around calling the functions.
     29         mask >>= (mask & 31);
     30         int intri = SkCLZ(mask);
     31         int porta = SkCLZ_portable(mask);
     32         REPORTER_ASSERT(reporter, intri == porta);
     33     }
     34 }
     35 
     36 static void test_quick_div(skiatest::Reporter* reporter) {
     37     /*
     38     The inverse table is generated by turning on SkDebugf in the following test code
     39     */
     40     SkFixed storage[kInverseTableSize * 2];
     41     SkFixed* table = storage + kInverseTableSize;
     42 
     43     // SkDebugf("static const int gFDot6INVERSE[] = {");
     44     for (SkFDot6 i=-kInverseTableSize; i<kInverseTableSize; i++) {
     45         if (i != 0) {
     46             table[i] = SkFDot6Div(SK_FDot6One, i);
     47             REPORTER_ASSERT(reporter, table[i] == gFDot6INVERSE[i + kInverseTableSize]);
     48         }
     49         // SkDebugf("%d, ", table[i]);
     50     }
     51     // SkDebugf("}\n");
     52 
     53 
     54     for (SkFDot6 a = -1024; a <= 1024; a++) {
     55         for (SkFDot6 b = -1024; b <= 1024; b++) {
     56             if (b != 0) {
     57                 SkFixed ourAnswer = QuickSkFDot6Div(a, b);
     58                 SkFixed directAnswer = SkFDot6Div(a, b);
     59                 REPORTER_ASSERT(reporter,
     60                     (directAnswer == 0 && ourAnswer == 0) ||
     61                     SkFixedDiv(SkAbs32(directAnswer - ourAnswer), SkAbs32(directAnswer)) <= 1 << 10
     62                 );
     63             }
     64         }
     65     }
     66 }
     67 
     68 ///////////////////////////////////////////////////////////////////////////////
     69 
     70 static float sk_fsel(float pred, float result_ge, float result_lt) {
     71     return pred >= 0 ? result_ge : result_lt;
     72 }
     73 
     74 static float fast_floor(float x) {
     75 //    float big = sk_fsel(x, 0x1.0p+23, -0x1.0p+23);
     76     float big = sk_fsel(x, (float)(1 << 23), -(float)(1 << 23));
     77     return (float)(x + big) - big;
     78 }
     79 
     80 static float std_floor(float x) {
     81     return sk_float_floor(x);
     82 }
     83 
     84 static void test_floor_value(skiatest::Reporter* reporter, float value) {
     85     float fast = fast_floor(value);
     86     float std = std_floor(value);
     87     if (std != fast) {
     88         ERRORF(reporter, "fast_floor(%.9g) == %.9g != %.9g == std_floor(%.9g)",
     89                value, fast, std, value);
     90     }
     91 }
     92 
     93 static void test_floor(skiatest::Reporter* reporter) {
     94     static const float gVals[] = {
     95         0, 1, 1.1f, 1.01f, 1.001f, 1.0001f, 1.00001f, 1.000001f, 1.0000001f
     96     };
     97 
     98     for (size_t i = 0; i < SK_ARRAY_COUNT(gVals); ++i) {
     99         test_floor_value(reporter, gVals[i]);
    100 //        test_floor_value(reporter, -gVals[i]);
    101     }
    102 }
    103 
    104 ///////////////////////////////////////////////////////////////////////////////
    105 
    106 // test that SkMul16ShiftRound and SkMulDiv255Round return the same result
    107 static void test_muldivround(skiatest::Reporter* reporter) {
    108 #if 0
    109     // this "complete" test is too slow, so we test a random sampling of it
    110 
    111     for (int a = 0; a <= 32767; ++a) {
    112         for (int b = 0; b <= 32767; ++b) {
    113             unsigned prod0 = SkMul16ShiftRound(a, b, 8);
    114             unsigned prod1 = SkMulDiv255Round(a, b);
    115             SkASSERT(prod0 == prod1);
    116         }
    117     }
    118 #endif
    119 
    120     SkRandom rand;
    121     for (int i = 0; i < 10000; ++i) {
    122         unsigned a = rand.nextU() & 0x7FFF;
    123         unsigned b = rand.nextU() & 0x7FFF;
    124 
    125         unsigned prod0 = SkMul16ShiftRound(a, b, 8);
    126         unsigned prod1 = SkMulDiv255Round(a, b);
    127 
    128         REPORTER_ASSERT(reporter, prod0 == prod1);
    129     }
    130 }
    131 
    132 static float float_blend(int src, int dst, float unit) {
    133     return dst + (src - dst) * unit;
    134 }
    135 
    136 static int blend31(int src, int dst, int a31) {
    137     return dst + ((src - dst) * a31 * 2114 >> 16);
    138     //    return dst + ((src - dst) * a31 * 33 >> 10);
    139 }
    140 
    141 static int blend31_slow(int src, int dst, int a31) {
    142     int prod = src * a31 + (31 - a31) * dst + 16;
    143     prod = (prod + (prod >> 5)) >> 5;
    144     return prod;
    145 }
    146 
    147 static int blend31_round(int src, int dst, int a31) {
    148     int prod = (src - dst) * a31 + 16;
    149     prod = (prod + (prod >> 5)) >> 5;
    150     return dst + prod;
    151 }
    152 
    153 static int blend31_old(int src, int dst, int a31) {
    154     a31 += a31 >> 4;
    155     return dst + ((src - dst) * a31 >> 5);
    156 }
    157 
    158 // suppress unused code warning
    159 static int (*blend_functions[])(int, int, int) = {
    160     blend31,
    161     blend31_slow,
    162     blend31_round,
    163     blend31_old
    164 };
    165 
    166 static void test_blend31() {
    167     int failed = 0;
    168     int death = 0;
    169     if (false) { // avoid bit rot, suppress warning
    170         failed = (*blend_functions[0])(0,0,0);
    171     }
    172     for (int src = 0; src <= 255; src++) {
    173         for (int dst = 0; dst <= 255; dst++) {
    174             for (int a = 0; a <= 31; a++) {
    175 //                int r0 = blend31(src, dst, a);
    176 //                int r0 = blend31_round(src, dst, a);
    177 //                int r0 = blend31_old(src, dst, a);
    178                 int r0 = blend31_slow(src, dst, a);
    179 
    180                 float f = float_blend(src, dst, a / 31.f);
    181                 int r1 = (int)f;
    182                 int r2 = SkScalarRoundToInt(f);
    183 
    184                 if (r0 != r1 && r0 != r2) {
    185                     SkDebugf("src:%d dst:%d a:%d result:%d float:%g\n",
    186                                  src,   dst, a,        r0,      f);
    187                     failed += 1;
    188                 }
    189                 if (r0 > 255) {
    190                     death += 1;
    191                     SkDebugf("death src:%d dst:%d a:%d result:%d float:%g\n",
    192                                         src,   dst, a,        r0,      f);
    193                 }
    194             }
    195         }
    196     }
    197     SkDebugf("---- failed %d death %d\n", failed, death);
    198 }
    199 
    200 static void test_blend(skiatest::Reporter* reporter) {
    201     for (int src = 0; src <= 255; src++) {
    202         for (int dst = 0; dst <= 255; dst++) {
    203             for (int a = 0; a <= 255; a++) {
    204                 int r0 = SkAlphaBlend255(src, dst, a);
    205                 float f1 = float_blend(src, dst, a / 255.f);
    206                 int r1 = SkScalarRoundToInt(f1);
    207 
    208                 if (r0 != r1) {
    209                     float diff = sk_float_abs(f1 - r1);
    210                     diff = sk_float_abs(diff - 0.5f);
    211                     if (diff > (1 / 255.f)) {
    212                         ERRORF(reporter, "src:%d dst:%d a:%d "
    213                                "result:%d float:%g\n", src, dst, a, r0, f1);
    214                     }
    215                 }
    216             }
    217         }
    218     }
    219 }
    220 
    221 static void check_length(skiatest::Reporter* reporter,
    222                          const SkPoint& p, SkScalar targetLen) {
    223     float x = SkScalarToFloat(p.fX);
    224     float y = SkScalarToFloat(p.fY);
    225     float len = sk_float_sqrt(x*x + y*y);
    226 
    227     len /= SkScalarToFloat(targetLen);
    228 
    229     REPORTER_ASSERT(reporter, len > 0.999f && len < 1.001f);
    230 }
    231 
    232 static float make_zero() {
    233     return sk_float_sin(0);
    234 }
    235 
    236 static void unittest_isfinite(skiatest::Reporter* reporter) {
    237     float nan = sk_float_asin(2);
    238     float inf = 1.0f / make_zero();
    239     float big = 3.40282e+038f;
    240 
    241     REPORTER_ASSERT(reporter, !SkScalarIsNaN(inf));
    242     REPORTER_ASSERT(reporter, !SkScalarIsNaN(-inf));
    243     REPORTER_ASSERT(reporter, !SkScalarIsFinite(inf));
    244     REPORTER_ASSERT(reporter, !SkScalarIsFinite(-inf));
    245 
    246     REPORTER_ASSERT(reporter,  SkScalarIsNaN(nan));
    247     REPORTER_ASSERT(reporter, !SkScalarIsNaN(big));
    248     REPORTER_ASSERT(reporter, !SkScalarIsNaN(-big));
    249     REPORTER_ASSERT(reporter, !SkScalarIsNaN(0));
    250 
    251     REPORTER_ASSERT(reporter, !SkScalarIsFinite(nan));
    252     REPORTER_ASSERT(reporter,  SkScalarIsFinite(big));
    253     REPORTER_ASSERT(reporter,  SkScalarIsFinite(-big));
    254     REPORTER_ASSERT(reporter,  SkScalarIsFinite(0));
    255 }
    256 
    257 static void unittest_half(skiatest::Reporter* reporter) {
    258     static const float gFloats[] = {
    259         0.f, 1.f, 0.5f, 0.499999f, 0.5000001f, 1.f/3,
    260         -0.f, -1.f, -0.5f, -0.499999f, -0.5000001f, -1.f/3
    261     };
    262 
    263     for (size_t i = 0; i < SK_ARRAY_COUNT(gFloats); ++i) {
    264         SkHalf h = SkFloatToHalf(gFloats[i]);
    265         float f = SkHalfToFloat(h);
    266         REPORTER_ASSERT(reporter, SkScalarNearlyEqual(f, gFloats[i]));
    267     }
    268 
    269     // check some special values
    270     union FloatUnion {
    271         uint32_t fU;
    272         float    fF;
    273     };
    274 
    275     static const FloatUnion largestPositiveHalf = { ((142 << 23) | (1023 << 13)) };
    276     SkHalf h = SkFloatToHalf(largestPositiveHalf.fF);
    277     float f = SkHalfToFloat(h);
    278     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(f, largestPositiveHalf.fF));
    279 
    280     static const FloatUnion largestNegativeHalf = { (1u << 31) | (142u << 23) | (1023u << 13) };
    281     h = SkFloatToHalf(largestNegativeHalf.fF);
    282     f = SkHalfToFloat(h);
    283     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(f, largestNegativeHalf.fF));
    284 
    285     static const FloatUnion smallestPositiveHalf = { 102 << 23 };
    286     h = SkFloatToHalf(smallestPositiveHalf.fF);
    287     f = SkHalfToFloat(h);
    288     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(f, smallestPositiveHalf.fF));
    289 
    290     static const FloatUnion overflowHalf = { ((143 << 23) | (1023 << 13)) };
    291     h = SkFloatToHalf(overflowHalf.fF);
    292     f = SkHalfToFloat(h);
    293     REPORTER_ASSERT(reporter, !SkScalarIsFinite(f) );
    294 
    295     static const FloatUnion underflowHalf = { 101 << 23 };
    296     h = SkFloatToHalf(underflowHalf.fF);
    297     f = SkHalfToFloat(h);
    298     REPORTER_ASSERT(reporter, f == 0.0f );
    299 
    300     static const FloatUnion inf32 = { 255 << 23 };
    301     h = SkFloatToHalf(inf32.fF);
    302     f = SkHalfToFloat(h);
    303     REPORTER_ASSERT(reporter, !SkScalarIsFinite(f) );
    304 
    305     static const FloatUnion nan32 = { 255 << 23 | 1 };
    306     h = SkFloatToHalf(nan32.fF);
    307     f = SkHalfToFloat(h);
    308     REPORTER_ASSERT(reporter, SkScalarIsNaN(f) );
    309 
    310 }
    311 
    312 template <typename RSqrtFn>
    313 static void test_rsqrt(skiatest::Reporter* reporter, RSqrtFn rsqrt) {
    314     const float maxRelativeError = 6.50196699e-4f;
    315 
    316     // test close to 0 up to 1
    317     float input = 0.000001f;
    318     for (int i = 0; i < 1000; ++i) {
    319         float exact = 1.0f/sk_float_sqrt(input);
    320         float estimate = rsqrt(input);
    321         float relativeError = sk_float_abs(exact - estimate)/exact;
    322         REPORTER_ASSERT(reporter, relativeError <= maxRelativeError);
    323         input += 0.001f;
    324     }
    325 
    326     // test 1 to ~100
    327     input = 1.0f;
    328     for (int i = 0; i < 1000; ++i) {
    329         float exact = 1.0f/sk_float_sqrt(input);
    330         float estimate = rsqrt(input);
    331         float relativeError = sk_float_abs(exact - estimate)/exact;
    332         REPORTER_ASSERT(reporter, relativeError <= maxRelativeError);
    333         input += 0.01f;
    334     }
    335 
    336     // test some big numbers
    337     input = 1000000.0f;
    338     for (int i = 0; i < 100; ++i) {
    339         float exact = 1.0f/sk_float_sqrt(input);
    340         float estimate = rsqrt(input);
    341         float relativeError = sk_float_abs(exact - estimate)/exact;
    342         REPORTER_ASSERT(reporter, relativeError <= maxRelativeError);
    343         input += 754326.f;
    344     }
    345 }
    346 
    347 static void test_muldiv255(skiatest::Reporter* reporter) {
    348     for (int a = 0; a <= 255; a++) {
    349         for (int b = 0; b <= 255; b++) {
    350             int ab = a * b;
    351             float s = ab / 255.0f;
    352             int round = (int)floorf(s + 0.5f);
    353             int trunc = (int)floorf(s);
    354 
    355             int iround = SkMulDiv255Round(a, b);
    356             int itrunc = SkMulDiv255Trunc(a, b);
    357 
    358             REPORTER_ASSERT(reporter, iround == round);
    359             REPORTER_ASSERT(reporter, itrunc == trunc);
    360 
    361             REPORTER_ASSERT(reporter, itrunc <= iround);
    362             REPORTER_ASSERT(reporter, iround <= a);
    363             REPORTER_ASSERT(reporter, iround <= b);
    364         }
    365     }
    366 }
    367 
    368 static void test_muldiv255ceiling(skiatest::Reporter* reporter) {
    369     for (int c = 0; c <= 255; c++) {
    370         for (int a = 0; a <= 255; a++) {
    371             int product = (c * a + 255);
    372             int expected_ceiling = (product + (product >> 8)) >> 8;
    373             int webkit_ceiling = (c * a + 254) / 255;
    374             REPORTER_ASSERT(reporter, expected_ceiling == webkit_ceiling);
    375             int skia_ceiling = SkMulDiv255Ceiling(c, a);
    376             REPORTER_ASSERT(reporter, skia_ceiling == webkit_ceiling);
    377         }
    378     }
    379 }
    380 
    381 static void test_copysign(skiatest::Reporter* reporter) {
    382     static const int32_t gTriples[] = {
    383         // x, y, expected result
    384         0, 0, 0,
    385         0, 1, 0,
    386         0, -1, 0,
    387         1, 0, 1,
    388         1, 1, 1,
    389         1, -1, -1,
    390         -1, 0, 1,
    391         -1, 1, 1,
    392         -1, -1, -1,
    393     };
    394     for (size_t i = 0; i < SK_ARRAY_COUNT(gTriples); i += 3) {
    395         REPORTER_ASSERT(reporter,
    396                         SkCopySign32(gTriples[i], gTriples[i+1]) == gTriples[i+2]);
    397         float x = (float)gTriples[i];
    398         float y = (float)gTriples[i+1];
    399         float expected = (float)gTriples[i+2];
    400         REPORTER_ASSERT(reporter, sk_float_copysign(x, y) == expected);
    401     }
    402 
    403     SkRandom rand;
    404     for (int j = 0; j < 1000; j++) {
    405         int ix = rand.nextS();
    406         REPORTER_ASSERT(reporter, SkCopySign32(ix, ix) == ix);
    407         REPORTER_ASSERT(reporter, SkCopySign32(ix, -ix) == -ix);
    408         REPORTER_ASSERT(reporter, SkCopySign32(-ix, ix) == ix);
    409         REPORTER_ASSERT(reporter, SkCopySign32(-ix, -ix) == -ix);
    410 
    411         SkScalar sx = rand.nextSScalar1();
    412         REPORTER_ASSERT(reporter, SkScalarCopySign(sx, sx) == sx);
    413         REPORTER_ASSERT(reporter, SkScalarCopySign(sx, -sx) == -sx);
    414         REPORTER_ASSERT(reporter, SkScalarCopySign(-sx, sx) == sx);
    415         REPORTER_ASSERT(reporter, SkScalarCopySign(-sx, -sx) == -sx);
    416     }
    417 }
    418 
    419 DEF_TEST(Math, reporter) {
    420     int         i;
    421     SkRandom    rand;
    422 
    423     // these should assert
    424 #if 0
    425     SkToS8(128);
    426     SkToS8(-129);
    427     SkToU8(256);
    428     SkToU8(-5);
    429 
    430     SkToS16(32768);
    431     SkToS16(-32769);
    432     SkToU16(65536);
    433     SkToU16(-5);
    434 
    435     if (sizeof(size_t) > 4) {
    436         SkToS32(4*1024*1024);
    437         SkToS32(-4*1024*1024);
    438         SkToU32(5*1024*1024);
    439         SkToU32(-5);
    440     }
    441 #endif
    442 
    443     test_muldiv255(reporter);
    444     test_muldiv255ceiling(reporter);
    445     test_copysign(reporter);
    446 
    447     {
    448         SkScalar x = SK_ScalarNaN;
    449         REPORTER_ASSERT(reporter, SkScalarIsNaN(x));
    450     }
    451 
    452     for (i = 0; i < 1000; i++) {
    453         int value = rand.nextS16();
    454         int max = rand.nextU16();
    455 
    456         int clamp = SkClampMax(value, max);
    457         int clamp2 = value < 0 ? 0 : (value > max ? max : value);
    458         REPORTER_ASSERT(reporter, clamp == clamp2);
    459     }
    460 
    461     for (i = 0; i < 10000; i++) {
    462         SkPoint p;
    463 
    464         // These random values are being treated as 32-bit-patterns, not as
    465         // ints; calling SkIntToScalar() here produces crashes.
    466         p.setLength((SkScalar) rand.nextS(),
    467                     (SkScalar) rand.nextS(),
    468                     SK_Scalar1);
    469         check_length(reporter, p, SK_Scalar1);
    470         p.setLength((SkScalar) (rand.nextS() >> 13),
    471                     (SkScalar) (rand.nextS() >> 13),
    472                     SK_Scalar1);
    473         check_length(reporter, p, SK_Scalar1);
    474     }
    475 
    476     {
    477         SkFixed result = SkFixedDiv(100, 100);
    478         REPORTER_ASSERT(reporter, result == SK_Fixed1);
    479         result = SkFixedDiv(1, SK_Fixed1);
    480         REPORTER_ASSERT(reporter, result == 1);
    481         result = SkFixedDiv(10 - 1, SK_Fixed1 * 3);
    482         REPORTER_ASSERT(reporter, result == 3);
    483     }
    484 
    485     {
    486         REPORTER_ASSERT(reporter, (SkFixedRoundToFixed(-SK_Fixed1 * 10) >> 1) == -SK_Fixed1 * 5);
    487         REPORTER_ASSERT(reporter, (SkFixedFloorToFixed(-SK_Fixed1 * 10) >> 1) == -SK_Fixed1 * 5);
    488         REPORTER_ASSERT(reporter, (SkFixedCeilToFixed(-SK_Fixed1 * 10) >> 1) == -SK_Fixed1 * 5);
    489     }
    490 
    491     unittest_isfinite(reporter);
    492     unittest_half(reporter);
    493     test_rsqrt(reporter, sk_float_rsqrt);
    494     test_rsqrt(reporter, sk_float_rsqrt_portable);
    495 
    496     for (i = 0; i < 10000; i++) {
    497         SkFixed numer = rand.nextS();
    498         SkFixed denom = rand.nextS();
    499         SkFixed result = SkFixedDiv(numer, denom);
    500         int64_t check = SkLeftShift((int64_t)numer, 16) / denom;
    501 
    502         (void)SkCLZ(numer);
    503         (void)SkCLZ(denom);
    504 
    505         REPORTER_ASSERT(reporter, result != (SkFixed)SK_NaN32);
    506         if (check > SK_MaxS32) {
    507             check = SK_MaxS32;
    508         } else if (check < -SK_MaxS32) {
    509             check = SK_MinS32;
    510         }
    511         if (result != (int32_t)check) {
    512             ERRORF(reporter, "\nFixed Divide: %8x / %8x -> %8x %8x\n", numer, denom, result, check);
    513         }
    514         REPORTER_ASSERT(reporter, result == (int32_t)check);
    515     }
    516 
    517     test_blend(reporter);
    518 
    519     if (false) test_floor(reporter);
    520 
    521     // disable for now
    522     if (false) test_blend31();  // avoid bit rot, suppress warning
    523 
    524     test_muldivround(reporter);
    525     test_clz(reporter);
    526     test_quick_div(reporter);
    527 }
    528 
    529 template <typename T> struct PairRec {
    530     T   fYin;
    531     T   fYang;
    532 };
    533 
    534 DEF_TEST(TestEndian, reporter) {
    535     static const PairRec<uint16_t> g16[] = {
    536         { 0x0,      0x0     },
    537         { 0xFFFF,   0xFFFF  },
    538         { 0x1122,   0x2211  },
    539     };
    540     static const PairRec<uint32_t> g32[] = {
    541         { 0x0,          0x0         },
    542         { 0xFFFFFFFF,   0xFFFFFFFF  },
    543         { 0x11223344,   0x44332211  },
    544     };
    545     static const PairRec<uint64_t> g64[] = {
    546         { 0x0,      0x0                             },
    547         { 0xFFFFFFFFFFFFFFFFULL,  0xFFFFFFFFFFFFFFFFULL  },
    548         { 0x1122334455667788ULL,  0x8877665544332211ULL  },
    549     };
    550 
    551     REPORTER_ASSERT(reporter, 0x1122 == SkTEndianSwap16<0x2211>::value);
    552     REPORTER_ASSERT(reporter, 0x11223344 == SkTEndianSwap32<0x44332211>::value);
    553     REPORTER_ASSERT(reporter, 0x1122334455667788ULL == SkTEndianSwap64<0x8877665544332211ULL>::value);
    554 
    555     for (size_t i = 0; i < SK_ARRAY_COUNT(g16); ++i) {
    556         REPORTER_ASSERT(reporter, g16[i].fYang == SkEndianSwap16(g16[i].fYin));
    557     }
    558     for (size_t i = 0; i < SK_ARRAY_COUNT(g32); ++i) {
    559         REPORTER_ASSERT(reporter, g32[i].fYang == SkEndianSwap32(g32[i].fYin));
    560     }
    561     for (size_t i = 0; i < SK_ARRAY_COUNT(g64); ++i) {
    562         REPORTER_ASSERT(reporter, g64[i].fYang == SkEndianSwap64(g64[i].fYin));
    563     }
    564 }
    565 
    566 template <typename T>
    567 static void test_divmod(skiatest::Reporter* r) {
    568     const struct {
    569         T numer;
    570         T denom;
    571     } kEdgeCases[] = {
    572         {(T)17, (T)17},
    573         {(T)17, (T)4},
    574         {(T)0,  (T)17},
    575         // For unsigned T these negatives are just some large numbers.  Doesn't hurt to test them.
    576         {(T)-17, (T)-17},
    577         {(T)-17, (T)4},
    578         {(T)17,  (T)-4},
    579         {(T)-17, (T)-4},
    580     };
    581 
    582     for (size_t i = 0; i < SK_ARRAY_COUNT(kEdgeCases); i++) {
    583         const T numer = kEdgeCases[i].numer;
    584         const T denom = kEdgeCases[i].denom;
    585         T div, mod;
    586         SkTDivMod(numer, denom, &div, &mod);
    587         REPORTER_ASSERT(r, numer/denom == div);
    588         REPORTER_ASSERT(r, numer%denom == mod);
    589     }
    590 
    591     SkRandom rand;
    592     for (size_t i = 0; i < 10000; i++) {
    593         const T numer = (T)rand.nextS();
    594         T denom = 0;
    595         while (0 == denom) {
    596             denom = (T)rand.nextS();
    597         }
    598         T div, mod;
    599         SkTDivMod(numer, denom, &div, &mod);
    600         REPORTER_ASSERT(r, numer/denom == div);
    601         REPORTER_ASSERT(r, numer%denom == mod);
    602     }
    603 }
    604 
    605 DEF_TEST(divmod_u8, r) {
    606     test_divmod<uint8_t>(r);
    607 }
    608 
    609 DEF_TEST(divmod_u16, r) {
    610     test_divmod<uint16_t>(r);
    611 }
    612 
    613 DEF_TEST(divmod_u32, r) {
    614     test_divmod<uint32_t>(r);
    615 }
    616 
    617 DEF_TEST(divmod_u64, r) {
    618     test_divmod<uint64_t>(r);
    619 }
    620 
    621 DEF_TEST(divmod_s8, r) {
    622     test_divmod<int8_t>(r);
    623 }
    624 
    625 DEF_TEST(divmod_s16, r) {
    626     test_divmod<int16_t>(r);
    627 }
    628 
    629 DEF_TEST(divmod_s32, r) {
    630     test_divmod<int32_t>(r);
    631 }
    632 
    633 DEF_TEST(divmod_s64, r) {
    634     test_divmod<int64_t>(r);
    635 }
    636 
    637 static void test_nextsizepow2(skiatest::Reporter* r, size_t test, size_t expectedAns) {
    638     size_t ans = GrNextSizePow2(test);
    639 
    640     REPORTER_ASSERT(r, ans == expectedAns);
    641     //SkDebugf("0x%zx -> 0x%zx (0x%zx)\n", test, ans, expectedAns);
    642 }
    643 
    644 DEF_TEST(GrNextSizePow2, reporter) {
    645     constexpr int kNumSizeTBits = 8 * sizeof(size_t);
    646 
    647     size_t test = 0, expectedAns = 1;
    648 
    649     test_nextsizepow2(reporter, test, expectedAns);
    650 
    651     test = 1; expectedAns = 1;
    652 
    653     for (int i = 1; i < kNumSizeTBits; ++i) {
    654         test_nextsizepow2(reporter, test, expectedAns);
    655 
    656         test++;
    657         expectedAns <<= 1;
    658 
    659         test_nextsizepow2(reporter, test, expectedAns);
    660 
    661         test = expectedAns;
    662     }
    663 
    664     // For the remaining three tests there is no higher power (of 2)
    665     test = 0x1;
    666     test <<= kNumSizeTBits-1;
    667     test_nextsizepow2(reporter, test, test);
    668 
    669     test++;
    670     test_nextsizepow2(reporter, test, test);
    671 
    672     test_nextsizepow2(reporter, SIZE_MAX, SIZE_MAX);
    673 }
    674 
    675 DEF_TEST(FloatSaturate32, reporter) {
    676     const struct {
    677         float   fFloat;
    678         int     fExpectedInt;
    679     } recs[] = {
    680         { 0, 0 },
    681         { 100.5f, 100 },
    682         { (float)SK_MaxS32, SK_MaxS32FitsInFloat },
    683         { (float)SK_MinS32, SK_MinS32FitsInFloat },
    684         { SK_MaxS32 * 100.0f, SK_MaxS32FitsInFloat },
    685         { SK_MinS32 * 100.0f, SK_MinS32FitsInFloat },
    686         { SK_ScalarInfinity, SK_MaxS32FitsInFloat },
    687         { SK_ScalarNegativeInfinity, SK_MinS32FitsInFloat },
    688         { SK_ScalarNaN, SK_MaxS32FitsInFloat },
    689     };
    690 
    691     for (auto r : recs) {
    692         int i = sk_float_saturate2int(r.fFloat);
    693         REPORTER_ASSERT(reporter, r.fExpectedInt == i);
    694     }
    695 }
    696 
    697 DEF_TEST(FloatSaturate64, reporter) {
    698     const struct {
    699         float   fFloat;
    700         int64_t fExpected64;
    701     } recs[] = {
    702         { 0, 0 },
    703         { 100.5f, 100 },
    704         { (float)SK_MaxS64, SK_MaxS64FitsInFloat },
    705         { (float)SK_MinS64, SK_MinS64FitsInFloat },
    706         { SK_MaxS64 * 100.0f, SK_MaxS64FitsInFloat },
    707         { SK_MinS64 * 100.0f, SK_MinS64FitsInFloat },
    708         { SK_ScalarInfinity, SK_MaxS64FitsInFloat },
    709         { SK_ScalarNegativeInfinity, SK_MinS64FitsInFloat },
    710         { SK_ScalarNaN, SK_MaxS64FitsInFloat },
    711     };
    712 
    713     for (auto r : recs) {
    714         int64_t i = sk_float_saturate2int64(r.fFloat);
    715         REPORTER_ASSERT(reporter, r.fExpected64 == i);
    716     }
    717 }
    718 
    719 DEF_TEST(DoubleSaturate32, reporter) {
    720     const struct {
    721         double  fDouble;
    722         int     fExpectedInt;
    723     } recs[] = {
    724         { 0, 0 },
    725         { 100.5, 100 },
    726         { SK_MaxS32, SK_MaxS32 },
    727         { SK_MinS32, SK_MinS32 },
    728         { SK_MaxS32 - 1, SK_MaxS32 - 1 },
    729         { SK_MinS32 + 1, SK_MinS32 + 1 },
    730         { SK_MaxS32 * 100.0, SK_MaxS32 },
    731         { SK_MinS32 * 100.0, SK_MinS32 },
    732         { SK_ScalarInfinity, SK_MaxS32 },
    733         { SK_ScalarNegativeInfinity, SK_MinS32 },
    734         { SK_ScalarNaN, SK_MaxS32 },
    735     };
    736 
    737     for (auto r : recs) {
    738         int i = sk_double_saturate2int(r.fDouble);
    739         REPORTER_ASSERT(reporter, r.fExpectedInt == i);
    740     }
    741 }
    742