tests/MathTest.cpp - platform/external/skqp - Gitiles


 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "Test.h"
 #include "SkFloatBits.h"
 #include "SkFloatingPoint.h"
 #include "SkMathPriv.h"
 #include "SkPoint.h"
 #include "SkRandom.h"
 #include "SkColorPriv.h"

 static void test_clz(skiatest::Reporter* reporter) {
     REPORTER_ASSERT(reporter, 32 == SkCLZ(0));
     REPORTER_ASSERT(reporter, 31 == SkCLZ(1));
     REPORTER_ASSERT(reporter, 1 == SkCLZ(1 << 30));
     REPORTER_ASSERT(reporter, 0 == SkCLZ(~0U));

     SkRandom rand;
     for (int i = 0; i < 1000; ++i) {
         uint32_t mask = rand.nextU();
         // need to get some zeros for testing, but in some obscure way so the
         // compiler won't "see" that, and work-around calling the functions.
         mask >>= (mask & 31);
         int intri = SkCLZ(mask);
         int porta = SkCLZ_portable(mask);
         REPORTER_ASSERT(reporter, intri == porta);
     }
 }

 ///////////////////////////////////////////////////////////////////////////////

 static float sk_fsel(float pred, float result_ge, float result_lt) {
     return pred >= 0 ? result_ge : result_lt;
 }

 static float fast_floor(float x) {
 //    float big = sk_fsel(x, 0x1.0p+23, -0x1.0p+23);
     float big = sk_fsel(x, (float)(1 << 23), -(float)(1 << 23));
     return (float)(x + big) - big;
 }

 static float std_floor(float x) {
     return sk_float_floor(x);
 }

 static void test_floor_value(skiatest::Reporter* reporter, float value) {
     float fast = fast_floor(value);
     float std = std_floor(value);
     REPORTER_ASSERT(reporter, std == fast);
 //    SkDebugf("value[%1.9f] std[%g] fast[%g] equal[%d]\n",
 //             value, std, fast, std == fast);
 }

 static void test_floor(skiatest::Reporter* reporter) {
     static const float gVals[] = {
         0, 1, 1.1f, 1.01f, 1.001f, 1.0001f, 1.00001f, 1.000001f, 1.0000001f
     };

     for (size_t i = 0; i < SK_ARRAY_COUNT(gVals); ++i) {
         test_floor_value(reporter, gVals[i]);
 //        test_floor_value(reporter, -gVals[i]);
     }
 }

 ///////////////////////////////////////////////////////////////////////////////

 // test that SkMul16ShiftRound and SkMulDiv255Round return the same result
 static void test_muldivround(skiatest::Reporter* reporter) {
 #if 0
     // this "complete" test is too slow, so we test a random sampling of it

     for (int a = 0; a <= 32767; ++a) {
         for (int b = 0; b <= 32767; ++b) {
             unsigned prod0 = SkMul16ShiftRound(a, b, 8);
             unsigned prod1 = SkMulDiv255Round(a, b);
             SkASSERT(prod0 == prod1);
         }
     }
 #endif

     SkRandom rand;
     for (int i = 0; i < 10000; ++i) {
         unsigned a = rand.nextU() & 0x7FFF;
         unsigned b = rand.nextU() & 0x7FFF;

         unsigned prod0 = SkMul16ShiftRound(a, b, 8);
         unsigned prod1 = SkMulDiv255Round(a, b);

         REPORTER_ASSERT(reporter, prod0 == prod1);
     }
 }

 static float float_blend(int src, int dst, float unit) {
     return dst + (src - dst) * unit;
 }

 static int blend31(int src, int dst, int a31) {
     return dst + ((src - dst) * a31 * 2114 >> 16);
     //    return dst + ((src - dst) * a31 * 33 >> 10);
 }

 static int blend31_slow(int src, int dst, int a31) {
     int prod = src * a31 + (31 - a31) * dst + 16;
     prod = (prod + (prod >> 5)) >> 5;
     return prod;
 }

 static int blend31_round(int src, int dst, int a31) {
     int prod = (src - dst) * a31 + 16;
     prod = (prod + (prod >> 5)) >> 5;
     return dst + prod;
 }

 static int blend31_old(int src, int dst, int a31) {
     a31 += a31 >> 4;
     return dst + ((src - dst) * a31 >> 5);
 }

 // suppress unused code warning
 static int (*blend_functions[])(int, int, int) = {
     blend31,
     blend31_slow,
     blend31_round,
     blend31_old
 };

 static void test_blend31() {
     int failed = 0;
     int death = 0;
     if (false) { // avoid bit rot, suppress warning
         failed = (*blend_functions[0])(0,0,0);
     }
     for (int src = 0; src <= 255; src++) {
         for (int dst = 0; dst <= 255; dst++) {
             for (int a = 0; a <= 31; a++) {
 //                int r0 = blend31(src, dst, a);
 //                int r0 = blend31_round(src, dst, a);
 //                int r0 = blend31_old(src, dst, a);
                 int r0 = blend31_slow(src, dst, a);

                 float f = float_blend(src, dst, a / 31.f);
                 int r1 = (int)f;
                 int r2 = SkScalarRoundToInt(f);

                 if (r0 != r1 && r0 != r2) {
                     SkDebugf("src:%d dst:%d a:%d result:%d float:%g\n",
                                   src,   dst, a,        r0,      f);
                     failed += 1;
                 }
                 if (r0 > 255) {
                     death += 1;
                     SkDebugf("death src:%d dst:%d a:%d result:%d float:%g\n",
                                         src,   dst, a,        r0,      f);
                 }
             }
         }
     }
     SkDebugf("---- failed %d death %d\n", failed, death);
 }

 static void test_blend(skiatest::Reporter* reporter) {
     for (int src = 0; src <= 255; src++) {
         for (int dst = 0; dst <= 255; dst++) {
             for (int a = 0; a <= 255; a++) {
                 int r0 = SkAlphaBlend255(src, dst, a);
                 float f1 = float_blend(src, dst, a / 255.f);
                 int r1 = SkScalarRoundToInt(f1);

                 if (r0 != r1) {
                     float diff = sk_float_abs(f1 - r1);
                     diff = sk_float_abs(diff - 0.5f);
                     if (diff > (1 / 255.f)) {
 #ifdef SK_DEBUG
                         SkDebugf("src:%d dst:%d a:%d result:%d float:%g\n",
                                  src, dst, a, r0, f1);
 #endif
                         REPORTER_ASSERT(reporter, false);
                     }
                 }
             }
         }
     }
 }

 #if defined(SkLONGLONG)
 static int symmetric_fixmul(int a, int b) {
     int sa = SkExtractSign(a);
     int sb = SkExtractSign(b);

     a = SkApplySign(a, sa);
     b = SkApplySign(b, sb);

 #if 1
     int c = (int)(((SkLONGLONG)a * b) >> 16);

     return SkApplySign(c, sa ^ sb);
 #else
     SkLONGLONG ab = (SkLONGLONG)a * b;
     if (sa ^ sb) {
         ab = -ab;
     }
     return ab >> 16;
 #endif
 }
 #endif

 static void check_length(skiatest::Reporter* reporter,
                          const SkPoint& p, SkScalar targetLen) {
     float x = SkScalarToFloat(p.fX);
     float y = SkScalarToFloat(p.fY);
     float len = sk_float_sqrt(x*x + y*y);

     len /= SkScalarToFloat(targetLen);

     REPORTER_ASSERT(reporter, len > 0.999f && len < 1.001f);
 }

 static float nextFloat(SkRandom& rand) {
     SkFloatIntUnion data;
     data.fSignBitInt = rand.nextU();
     return data.fFloat;
 }

 /*  returns true if a == b as resulting from (int)x. Since it is undefined
  what to do if the float exceeds 2^32-1, we check for that explicitly.
  */
 static bool equal_float_native_skia(float x, uint32_t ni, uint32_t si) {
     if (!(x == x)) {    // NAN
         return ((int32_t)si) == SK_MaxS32 || ((int32_t)si) == SK_MinS32;
     }
     // for out of range, C is undefined, but skia always should return NaN32
     if (x > SK_MaxS32) {
         return ((int32_t)si) == SK_MaxS32;
     }
     if (x < -SK_MaxS32) {
         return ((int32_t)si) == SK_MinS32;
     }
     return si == ni;
 }

 static void assert_float_equal(skiatest::Reporter* reporter, const char op[],
                                float x, uint32_t ni, uint32_t si) {
     if (!equal_float_native_skia(x, ni, si)) {
         SkString desc;
         uint32_t xi = SkFloat2Bits(x);
         desc.printf("%s float %g bits %x native %x skia %x\n", op, x, xi, ni, si);
         reporter->reportFailed(desc);
     }
 }

 static void test_float_cast(skiatest::Reporter* reporter, float x) {
     int ix = (int)x;
     int iix = SkFloatToIntCast(x);
     assert_float_equal(reporter, "cast", x, ix, iix);
 }

 static void test_float_floor(skiatest::Reporter* reporter, float x) {
     int ix = (int)floor(x);
     int iix = SkFloatToIntFloor(x);
     assert_float_equal(reporter, "floor", x, ix, iix);
 }

 static void test_float_round(skiatest::Reporter* reporter, float x) {
     double xx = x + 0.5;    // need intermediate double to avoid temp loss
     int ix = (int)floor(xx);
     int iix = SkFloatToIntRound(x);
     assert_float_equal(reporter, "round", x, ix, iix);
 }

 static void test_float_ceil(skiatest::Reporter* reporter, float x) {
     int ix = (int)ceil(x);
     int iix = SkFloatToIntCeil(x);
     assert_float_equal(reporter, "ceil", x, ix, iix);
 }

 static void test_float_conversions(skiatest::Reporter* reporter, float x) {
     test_float_cast(reporter, x);
     test_float_floor(reporter, x);
     test_float_round(reporter, x);
     test_float_ceil(reporter, x);
 }

 static void test_int2float(skiatest::Reporter* reporter, int ival) {
     float x0 = (float)ival;
     float x1 = SkIntToFloatCast(ival);
     float x2 = SkIntToFloatCast_NoOverflowCheck(ival);
     REPORTER_ASSERT(reporter, x0 == x1);
     REPORTER_ASSERT(reporter, x0 == x2);
 }

 static void unittest_fastfloat(skiatest::Reporter* reporter) {
     SkRandom rand;
     size_t i;

     static const float gFloats[] = {
         0.f, 1.f, 0.5f, 0.499999f, 0.5000001f, 1.f/3,
         0.000000001f, 1000000000.f,     // doesn't overflow
         0.0000000001f, 10000000000.f    // does overflow
     };
     for (i = 0; i < SK_ARRAY_COUNT(gFloats); i++) {
         test_float_conversions(reporter, gFloats[i]);
         test_float_conversions(reporter, -gFloats[i]);
     }

     for (int outer = 0; outer < 100; outer++) {
         rand.setSeed(outer);
         for (i = 0; i < 100000; i++) {
             float x = nextFloat(rand);
             test_float_conversions(reporter, x);
         }

         test_int2float(reporter, 0);
         test_int2float(reporter, 1);
         test_int2float(reporter, -1);
         for (i = 0; i < 100000; i++) {
             // for now only test ints that are 24bits or less, since we don't
             // round (down) large ints the same as IEEE...
             int ival = rand.nextU() & 0xFFFFFF;
             test_int2float(reporter, ival);
             test_int2float(reporter, -ival);
         }
     }
 }

 #ifdef SK_SCALAR_IS_FLOAT
 static float make_zero() {
     return sk_float_sin(0);
 }
 #endif

 static void unittest_isfinite(skiatest::Reporter* reporter) {
 #ifdef SK_SCALAR_IS_FLOAT
     float nan = sk_float_asin(2);
     float inf = 1.0f / make_zero();
     float big = 3.40282e+038f;

     REPORTER_ASSERT(reporter, !SkScalarIsNaN(inf));
     REPORTER_ASSERT(reporter, !SkScalarIsNaN(-inf));
     REPORTER_ASSERT(reporter, !SkScalarIsFinite(inf));
     REPORTER_ASSERT(reporter, !SkScalarIsFinite(-inf));
 #else
     SkFixed nan = SK_FixedNaN;
     SkFixed big = SK_FixedMax;
 #endif

     REPORTER_ASSERT(reporter,  SkScalarIsNaN(nan));
     REPORTER_ASSERT(reporter, !SkScalarIsNaN(big));
     REPORTER_ASSERT(reporter, !SkScalarIsNaN(-big));
     REPORTER_ASSERT(reporter, !SkScalarIsNaN(0));

     REPORTER_ASSERT(reporter, !SkScalarIsFinite(nan));
     REPORTER_ASSERT(reporter,  SkScalarIsFinite(big));
     REPORTER_ASSERT(reporter,  SkScalarIsFinite(-big));
     REPORTER_ASSERT(reporter,  SkScalarIsFinite(0));
 }

 static void test_muldiv255(skiatest::Reporter* reporter) {
     for (int a = 0; a <= 255; a++) {
         for (int b = 0; b <= 255; b++) {
             int ab = a * b;
             float s = ab / 255.0f;
             int round = (int)floorf(s + 0.5f);
             int trunc = (int)floorf(s);

             int iround = SkMulDiv255Round(a, b);
             int itrunc = SkMulDiv255Trunc(a, b);

             REPORTER_ASSERT(reporter, iround == round);
             REPORTER_ASSERT(reporter, itrunc == trunc);

             REPORTER_ASSERT(reporter, itrunc <= iround);
             REPORTER_ASSERT(reporter, iround <= a);
             REPORTER_ASSERT(reporter, iround <= b);
         }
     }
 }

 static void test_muldiv255ceiling(skiatest::Reporter* reporter) {
     for (int c = 0; c <= 255; c++) {
         for (int a = 0; a <= 255; a++) {
             int product = (c * a + 255);
             int expected_ceiling = (product + (product >> 8)) >> 8;
             int webkit_ceiling = (c * a + 254) / 255;
             REPORTER_ASSERT(reporter, expected_ceiling == webkit_ceiling);
             int skia_ceiling = SkMulDiv255Ceiling(c, a);
             REPORTER_ASSERT(reporter, skia_ceiling == webkit_ceiling);
         }
     }
 }

 static void test_copysign(skiatest::Reporter* reporter) {
     static const int32_t gTriples[] = {
         // x, y, expected result
         0, 0, 0,
         0, 1, 0,
         0, -1, 0,
         1, 0, 1,
         1, 1, 1,
         1, -1, -1,
         -1, 0, 1,
         -1, 1, 1,
         -1, -1, -1,
     };
     for (size_t i = 0; i < SK_ARRAY_COUNT(gTriples); i += 3) {
         REPORTER_ASSERT(reporter,
                         SkCopySign32(gTriples[i], gTriples[i+1]) == gTriples[i+2]);
         float x = (float)gTriples[i];
         float y = (float)gTriples[i+1];
         float expected = (float)gTriples[i+2];
         REPORTER_ASSERT(reporter, sk_float_copysign(x, y) == expected);
     }

     SkRandom rand;
     for (int j = 0; j < 1000; j++) {
         int ix = rand.nextS();
         REPORTER_ASSERT(reporter, SkCopySign32(ix, ix) == ix);
         REPORTER_ASSERT(reporter, SkCopySign32(ix, -ix) == -ix);
         REPORTER_ASSERT(reporter, SkCopySign32(-ix, ix) == ix);
         REPORTER_ASSERT(reporter, SkCopySign32(-ix, -ix) == -ix);

         SkScalar sx = rand.nextSScalar1();
         REPORTER_ASSERT(reporter, SkScalarCopySign(sx, sx) == sx);
         REPORTER_ASSERT(reporter, SkScalarCopySign(sx, -sx) == -sx);
         REPORTER_ASSERT(reporter, SkScalarCopySign(-sx, sx) == sx);
         REPORTER_ASSERT(reporter, SkScalarCopySign(-sx, -sx) == -sx);
     }
 }

 static void TestMath(skiatest::Reporter* reporter) {
     int         i;
     int32_t     x;
     SkRandom    rand;

     // these should assert
 #if 0
     SkToS8(128);
     SkToS8(-129);
     SkToU8(256);
     SkToU8(-5);

     SkToS16(32768);
     SkToS16(-32769);
     SkToU16(65536);
     SkToU16(-5);

     if (sizeof(size_t) > 4) {
         SkToS32(4*1024*1024);
         SkToS32(-4*1024*1024);
         SkToU32(5*1024*1024);
         SkToU32(-5);
     }
 #endif

     test_muldiv255(reporter);
     test_muldiv255ceiling(reporter);
     test_copysign(reporter);

     {
         SkScalar x = SK_ScalarNaN;
         REPORTER_ASSERT(reporter, SkScalarIsNaN(x));
     }

     for (i = 1; i <= 10; i++) {
         x = SkCubeRootBits(i*i*i, 11);
         REPORTER_ASSERT(reporter, x == i);
     }

     x = SkFixedSqrt(SK_Fixed1);
     REPORTER_ASSERT(reporter, x == SK_Fixed1);
     x = SkFixedSqrt(SK_Fixed1/4);
     REPORTER_ASSERT(reporter, x == SK_Fixed1/2);
     x = SkFixedSqrt(SK_Fixed1*4);
     REPORTER_ASSERT(reporter, x == SK_Fixed1*2);

     x = SkFractSqrt(SK_Fract1);
     REPORTER_ASSERT(reporter, x == SK_Fract1);
     x = SkFractSqrt(SK_Fract1/4);
     REPORTER_ASSERT(reporter, x == SK_Fract1/2);
     x = SkFractSqrt(SK_Fract1/16);
     REPORTER_ASSERT(reporter, x == SK_Fract1/4);

     for (i = 1; i < 100; i++) {
         x = SkFixedSqrt(SK_Fixed1 * i * i);
         REPORTER_ASSERT(reporter, x == SK_Fixed1 * i);
     }

     for (i = 0; i < 1000; i++) {
         int value = rand.nextS16();
         int max = rand.nextU16();

         int clamp = SkClampMax(value, max);
         int clamp2 = value < 0 ? 0 : (value > max ? max : value);
         REPORTER_ASSERT(reporter, clamp == clamp2);
     }

     for (i = 0; i < 10000; i++) {
         SkPoint p;

         // These random values are being treated as 32-bit-patterns, not as
         // ints; calling SkIntToScalar() here produces crashes.
         p.setLength((SkScalar) rand.nextS(),
                     (SkScalar) rand.nextS(),
                     SK_Scalar1);
         check_length(reporter, p, SK_Scalar1);
         p.setLength((SkScalar) (rand.nextS() >> 13),
                     (SkScalar) (rand.nextS() >> 13),
                     SK_Scalar1);
         check_length(reporter, p, SK_Scalar1);
     }

     {
         SkFixed result = SkFixedDiv(100, 100);
         REPORTER_ASSERT(reporter, result == SK_Fixed1);
         result = SkFixedDiv(1, SK_Fixed1);
         REPORTER_ASSERT(reporter, result == 1);
     }

     unittest_fastfloat(reporter);
     unittest_isfinite(reporter);

 #ifdef SkLONGLONG
     for (i = 0; i < 10000; i++) {
         SkFixed numer = rand.nextS();
         SkFixed denom = rand.nextS();
         SkFixed result = SkFixedDiv(numer, denom);
         SkLONGLONG check = ((SkLONGLONG)numer << 16) / denom;

         (void)SkCLZ(numer);
         (void)SkCLZ(denom);

         REPORTER_ASSERT(reporter, result != (SkFixed)SK_NaN32);
         if (check > SK_MaxS32) {
             check = SK_MaxS32;
         } else if (check < -SK_MaxS32) {
             check = SK_MinS32;
         }
         REPORTER_ASSERT(reporter, result == (int32_t)check);

         result = SkFractDiv(numer, denom);
         check = ((SkLONGLONG)numer << 30) / denom;

         REPORTER_ASSERT(reporter, result != (SkFixed)SK_NaN32);
         if (check > SK_MaxS32) {
             check = SK_MaxS32;
         } else if (check < -SK_MaxS32) {
             check = SK_MinS32;
         }
         REPORTER_ASSERT(reporter, result == (int32_t)check);

         // make them <= 2^24, so we don't overflow in fixmul
         numer = numer << 8 >> 8;
         denom = denom << 8 >> 8;

         result = SkFixedMul(numer, denom);
         SkFixed r2 = symmetric_fixmul(numer, denom);
         //        SkASSERT(result == r2);

         result = SkFixedMul(numer, numer);
         r2 = SkFixedSquare(numer);
         REPORTER_ASSERT(reporter, result == r2);

         if (numer >= 0 && denom >= 0) {
             SkFixed mean = SkFixedMean(numer, denom);
             float prod = SkFixedToFloat(numer) * SkFixedToFloat(denom);
             float fm = sk_float_sqrt(sk_float_abs(prod));
             SkFixed mean2 = SkFloatToFixed(fm);
             int diff = SkAbs32(mean - mean2);
             REPORTER_ASSERT(reporter, diff <= 1);
         }

         {
             SkFixed mod = SkFixedMod(numer, denom);
             float n = SkFixedToFloat(numer);
             float d = SkFixedToFloat(denom);
             float m = sk_float_mod(n, d);
             // ensure the same sign
             REPORTER_ASSERT(reporter, mod == 0 || (mod < 0) == (m < 0));
             int diff = SkAbs32(mod - SkFloatToFixed(m));
             REPORTER_ASSERT(reporter, (diff >> 7) == 0);
         }
     }
 #endif

     for (i = 0; i < 10000; i++) {
         SkFract x = rand.nextU() >> 1;
         double xx = (double)x / SK_Fract1;
         SkFract xr = SkFractSqrt(x);
         SkFract check = SkFloatToFract(sqrt(xx));
         REPORTER_ASSERT(reporter, xr == check ||
                                   xr == check-1 ||
                                   xr == check+1);

         xr = SkFixedSqrt(x);
         xx = (double)x / SK_Fixed1;
         check = SkFloatToFixed(sqrt(xx));
         REPORTER_ASSERT(reporter, xr == check || xr == check-1);

         xr = SkSqrt32(x);
         xx = (double)x;
         check = (int32_t)sqrt(xx);
         REPORTER_ASSERT(reporter, xr == check || xr == check-1);
     }

 #if !defined(SK_SCALAR_IS_FLOAT)
     {
         SkFixed s, c;
         s = SkFixedSinCos(0, &c);
         REPORTER_ASSERT(reporter, s == 0);
         REPORTER_ASSERT(reporter, c == SK_Fixed1);
     }

     int maxDiff = 0;
     for (i = 0; i < 1000; i++) {
         SkFixed rads = rand.nextS() >> 10;
         double frads = SkFixedToFloat(rads);

         SkFixed s, c;
         s = SkScalarSinCos(rads, &c);

         double fs = sin(frads);
         double fc = cos(frads);

         SkFixed is = SkFloatToFixed(fs);
         SkFixed ic = SkFloatToFixed(fc);

         maxDiff = SkMax32(maxDiff, SkAbs32(is - s));
         maxDiff = SkMax32(maxDiff, SkAbs32(ic - c));
     }
     SkDebugf("SinCos: maximum error = %d\n", maxDiff);
 #endif

 #ifdef SK_SCALAR_IS_FLOAT
     test_blend(reporter);
 #endif

     if (false) test_floor(reporter);

     // disable for now
     if (false) test_blend31();  // avoid bit rot, suppress warning

     test_muldivround(reporter);
     test_clz(reporter);
 }

 #include "TestClassDef.h"
 DEFINE_TESTCLASS("Math", MathTestClass, TestMath)

 ///////////////////////////////////////////////////////////////////////////////

 #include "SkEndian.h"

 template <typename T> struct PairRec {
     T   fYin;
     T   fYang;
 };

 static void TestEndian(skiatest::Reporter* reporter) {
     static const PairRec<uint16_t> g16[] = {
         { 0x0,      0x0     },
         { 0xFFFF,   0xFFFF  },
         { 0x1122,   0x2211  },
     };
     static const PairRec<uint32_t> g32[] = {
         { 0x0,          0x0         },
         { 0xFFFFFFFF,   0xFFFFFFFF  },
         { 0x11223344,   0x44332211  },
     };
     static const PairRec<uint64_t> g64[] = {
         { 0x0,      0x0                             },
         { 0xFFFFFFFFFFFFFFFFULL,  0xFFFFFFFFFFFFFFFFULL  },
         { 0x1122334455667788ULL,  0x8877665544332211ULL  },
     };

     REPORTER_ASSERT(reporter, 0x1122 == SkTEndianSwap16<0x2211>::value);
     REPORTER_ASSERT(reporter, 0x11223344 == SkTEndianSwap32<0x44332211>::value);
     REPORTER_ASSERT(reporter, 0x1122334455667788ULL == SkTEndianSwap64<0x8877665544332211ULL>::value);

     for (size_t i = 0; i < SK_ARRAY_COUNT(g16); ++i) {
         REPORTER_ASSERT(reporter, g16[i].fYang == SkEndianSwap16(g16[i].fYin));
     }
     for (size_t i = 0; i < SK_ARRAY_COUNT(g32); ++i) {
         REPORTER_ASSERT(reporter, g32[i].fYang == SkEndianSwap32(g32[i].fYin));
     }
     for (size_t i = 0; i < SK_ARRAY_COUNT(g64); ++i) {
         REPORTER_ASSERT(reporter, g64[i].fYang == SkEndianSwap64(g64[i].fYin));
     }
 }

 DEFINE_TESTCLASS("Endian", EndianTestClass, TestEndian)

 template <typename T>
 static void test_divmod(skiatest::Reporter* r) {
     const struct {
         T numer;
         T denom;
     } kEdgeCases[] = {
         {(T)17, (T)17},
         {(T)17, (T)4},
         {(T)0,  (T)17},
         // For unsigned T these negatives are just some large numbers.  Doesn't hurt to test them.
         {(T)-17, (T)-17},
         {(T)-17, (T)4},
         {(T)17,  (T)-4},
         {(T)-17, (T)-4},
     };

     for (size_t i = 0; i < SK_ARRAY_COUNT(kEdgeCases); i++) {
         const T numer = kEdgeCases[i].numer;
         const T denom = kEdgeCases[i].denom;
         T div, mod;
         SkTDivMod(numer, denom, &div, &mod);
         REPORTER_ASSERT(r, numer/denom == div);
         REPORTER_ASSERT(r, numer%denom == mod);
     }

     SkRandom rand;
     for (size_t i = 0; i < 10000; i++) {
         const T numer = (T)rand.nextS();
         T denom = 0;
         while (0 == denom) {
             denom = (T)rand.nextS();
         }
         T div, mod;
         SkTDivMod(numer, denom, &div, &mod);
         REPORTER_ASSERT(r, numer/denom == div);
         REPORTER_ASSERT(r, numer%denom == mod);
     }
 }

 DEF_TEST(divmod_u8, r) {
     test_divmod<uint8_t>(r);
 }

 DEF_TEST(divmod_u16, r) {
     test_divmod<uint16_t>(r);
 }

 DEF_TEST(divmod_u32, r) {
     test_divmod<uint32_t>(r);
 }

 DEF_TEST(divmod_u64, r) {
     test_divmod<uint64_t>(r);
 }

 DEF_TEST(divmod_s8, r) {
     test_divmod<int8_t>(r);
 }

 DEF_TEST(divmod_s16, r) {
     test_divmod<int16_t>(r);
 }

 DEF_TEST(divmod_s32, r) {
     test_divmod<int32_t>(r);
 }

 DEF_TEST(divmod_s64, r) {
     test_divmod<int64_t>(r);
 }

	/*
	* Copyright 2011 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/
	#include "Test.h"
	#include "SkFloatBits.h"
	#include "SkFloatingPoint.h"
	#include "SkMathPriv.h"
	#include "SkPoint.h"
	#include "SkRandom.h"
	#include "SkColorPriv.h"

	static void test_clz(skiatest::Reporter* reporter) {
	REPORTER_ASSERT(reporter, 32 == SkCLZ(0));
	REPORTER_ASSERT(reporter, 31 == SkCLZ(1));
	REPORTER_ASSERT(reporter, 1 == SkCLZ(1 << 30));
	REPORTER_ASSERT(reporter, 0 == SkCLZ(~0U));

	SkRandom rand;
	for (int i = 0; i < 1000; ++i) {
	uint32_t mask = rand.nextU();
	// need to get some zeros for testing, but in some obscure way so the
	// compiler won't "see" that, and work-around calling the functions.
	mask >>= (mask & 31);
	int intri = SkCLZ(mask);
	int porta = SkCLZ_portable(mask);
	REPORTER_ASSERT(reporter, intri == porta);
	}
	}

	///////////////////////////////////////////////////////////////////////////////

	static float sk_fsel(float pred, float result_ge, float result_lt) {
	return pred >= 0 ? result_ge : result_lt;
	}

	static float fast_floor(float x) {
	// float big = sk_fsel(x, 0x1.0p+23, -0x1.0p+23);
	float big = sk_fsel(x, (float)(1 << 23), -(float)(1 << 23));
	return (float)(x + big) - big;
	}

	static float std_floor(float x) {
	return sk_float_floor(x);
	}

	static void test_floor_value(skiatest::Reporter* reporter, float value) {
	float fast = fast_floor(value);
	float std = std_floor(value);
	REPORTER_ASSERT(reporter, std == fast);
	// SkDebugf("value[%1.9f] std[%g] fast[%g] equal[%d]\n",
	// value, std, fast, std == fast);
	}

	static void test_floor(skiatest::Reporter* reporter) {
	static const float gVals[] = {
	0, 1, 1.1f, 1.01f, 1.001f, 1.0001f, 1.00001f, 1.000001f, 1.0000001f
	};

	for (size_t i = 0; i < SK_ARRAY_COUNT(gVals); ++i) {
	test_floor_value(reporter, gVals[i]);
	// test_floor_value(reporter, -gVals[i]);
	}
	}

	///////////////////////////////////////////////////////////////////////////////

	// test that SkMul16ShiftRound and SkMulDiv255Round return the same result
	static void test_muldivround(skiatest::Reporter* reporter) {
	#if 0
	// this "complete" test is too slow, so we test a random sampling of it

	for (int a = 0; a <= 32767; ++a) {
	for (int b = 0; b <= 32767; ++b) {
	unsigned prod0 = SkMul16ShiftRound(a, b, 8);
	unsigned prod1 = SkMulDiv255Round(a, b);
	SkASSERT(prod0 == prod1);
	}
	}
	#endif

	SkRandom rand;
	for (int i = 0; i < 10000; ++i) {
	unsigned a = rand.nextU() & 0x7FFF;
	unsigned b = rand.nextU() & 0x7FFF;

	unsigned prod0 = SkMul16ShiftRound(a, b, 8);
	unsigned prod1 = SkMulDiv255Round(a, b);

	REPORTER_ASSERT(reporter, prod0 == prod1);
	}
	}

	static float float_blend(int src, int dst, float unit) {
	return dst + (src - dst) * unit;
	}

	static int blend31(int src, int dst, int a31) {
	return dst + ((src - dst) * a31 * 2114 >> 16);
	// return dst + ((src - dst) * a31 * 33 >> 10);
	}

	static int blend31_slow(int src, int dst, int a31) {
	int prod = src * a31 + (31 - a31) * dst + 16;
	prod = (prod + (prod >> 5)) >> 5;
	return prod;
	}

	static int blend31_round(int src, int dst, int a31) {
	int prod = (src - dst) * a31 + 16;
	prod = (prod + (prod >> 5)) >> 5;
	return dst + prod;
	}

	static int blend31_old(int src, int dst, int a31) {
	a31 += a31 >> 4;
	return dst + ((src - dst) * a31 >> 5);
	}

	// suppress unused code warning
	static int (*blend_functions[])(int, int, int) = {
	blend31,
	blend31_slow,
	blend31_round,
	blend31_old
	};

	static void test_blend31() {
	int failed = 0;
	int death = 0;
	if (false) { // avoid bit rot, suppress warning
	failed = (*blend_functions[0])(0,0,0);
	}
	for (int src = 0; src <= 255; src++) {
	for (int dst = 0; dst <= 255; dst++) {
	for (int a = 0; a <= 31; a++) {
	// int r0 = blend31(src, dst, a);
	// int r0 = blend31_round(src, dst, a);
	// int r0 = blend31_old(src, dst, a);
	int r0 = blend31_slow(src, dst, a);

	float f = float_blend(src, dst, a / 31.f);
	int r1 = (int)f;
	int r2 = SkScalarRoundToInt(f);

	if (r0 != r1 && r0 != r2) {
	SkDebugf("src:%d dst:%d a:%d result:%d float:%g\n",
	src, dst, a, r0, f);
	failed += 1;
	}
	if (r0 > 255) {
	death += 1;
	SkDebugf("death src:%d dst:%d a:%d result:%d float:%g\n",
	src, dst, a, r0, f);
	}
	}
	}
	}
	SkDebugf("---- failed %d death %d\n", failed, death);
	}

	static void test_blend(skiatest::Reporter* reporter) {
	for (int src = 0; src <= 255; src++) {
	for (int dst = 0; dst <= 255; dst++) {
	for (int a = 0; a <= 255; a++) {
	int r0 = SkAlphaBlend255(src, dst, a);
	float f1 = float_blend(src, dst, a / 255.f);
	int r1 = SkScalarRoundToInt(f1);

	if (r0 != r1) {
	float diff = sk_float_abs(f1 - r1);
	diff = sk_float_abs(diff - 0.5f);
	if (diff > (1 / 255.f)) {
	#ifdef SK_DEBUG
	SkDebugf("src:%d dst:%d a:%d result:%d float:%g\n",
	src, dst, a, r0, f1);
	#endif
	REPORTER_ASSERT(reporter, false);
	}
	}
	}
	}
	}
	}

	#if defined(SkLONGLONG)
	static int symmetric_fixmul(int a, int b) {
	int sa = SkExtractSign(a);
	int sb = SkExtractSign(b);

	a = SkApplySign(a, sa);
	b = SkApplySign(b, sb);

	#if 1
	int c = (int)(((SkLONGLONG)a * b) >> 16);

	return SkApplySign(c, sa ^ sb);
	#else
	SkLONGLONG ab = (SkLONGLONG)a * b;
	if (sa ^ sb) {
	ab = -ab;
	}
	return ab >> 16;
	#endif
	}
	#endif

	static void check_length(skiatest::Reporter* reporter,
	const SkPoint& p, SkScalar targetLen) {
	float x = SkScalarToFloat(p.fX);
	float y = SkScalarToFloat(p.fY);
	float len = sk_float_sqrt(xx + yy);

	len /= SkScalarToFloat(targetLen);

	REPORTER_ASSERT(reporter, len > 0.999f && len < 1.001f);
	}

	static float nextFloat(SkRandom& rand) {
	SkFloatIntUnion data;
	data.fSignBitInt = rand.nextU();
	return data.fFloat;
	}

	/* returns true if a == b as resulting from (int)x. Since it is undefined
	what to do if the float exceeds 2^32-1, we check for that explicitly.
	*/
	static bool equal_float_native_skia(float x, uint32_t ni, uint32_t si) {
	if (!(x == x)) { // NAN
	return ((int32_t)si) == SK_MaxS32 \|\| ((int32_t)si) == SK_MinS32;
	}
	// for out of range, C is undefined, but skia always should return NaN32
	if (x > SK_MaxS32) {
	return ((int32_t)si) == SK_MaxS32;
	}
	if (x < -SK_MaxS32) {
	return ((int32_t)si) == SK_MinS32;
	}
	return si == ni;
	}

	static void assert_float_equal(skiatest::Reporter* reporter, const char op[],
	float x, uint32_t ni, uint32_t si) {
	if (!equal_float_native_skia(x, ni, si)) {
	SkString desc;
	uint32_t xi = SkFloat2Bits(x);
	desc.printf("%s float %g bits %x native %x skia %x\n", op, x, xi, ni, si);
	reporter->reportFailed(desc);
	}
	}

	static void test_float_cast(skiatest::Reporter* reporter, float x) {
	int ix = (int)x;
	int iix = SkFloatToIntCast(x);
	assert_float_equal(reporter, "cast", x, ix, iix);
	}

	static void test_float_floor(skiatest::Reporter* reporter, float x) {
	int ix = (int)floor(x);
	int iix = SkFloatToIntFloor(x);
	assert_float_equal(reporter, "floor", x, ix, iix);
	}

	static void test_float_round(skiatest::Reporter* reporter, float x) {
	double xx = x + 0.5; // need intermediate double to avoid temp loss
	int ix = (int)floor(xx);
	int iix = SkFloatToIntRound(x);
	assert_float_equal(reporter, "round", x, ix, iix);
	}

	static void test_float_ceil(skiatest::Reporter* reporter, float x) {
	int ix = (int)ceil(x);
	int iix = SkFloatToIntCeil(x);
	assert_float_equal(reporter, "ceil", x, ix, iix);
	}

	static void test_float_conversions(skiatest::Reporter* reporter, float x) {
	test_float_cast(reporter, x);
	test_float_floor(reporter, x);
	test_float_round(reporter, x);
	test_float_ceil(reporter, x);
	}

	static void test_int2float(skiatest::Reporter* reporter, int ival) {
	float x0 = (float)ival;
	float x1 = SkIntToFloatCast(ival);
	float x2 = SkIntToFloatCast_NoOverflowCheck(ival);
	REPORTER_ASSERT(reporter, x0 == x1);
	REPORTER_ASSERT(reporter, x0 == x2);
	}

	static void unittest_fastfloat(skiatest::Reporter* reporter) {
	SkRandom rand;
	size_t i;

	static const float gFloats[] = {
	0.f, 1.f, 0.5f, 0.499999f, 0.5000001f, 1.f/3,
	0.000000001f, 1000000000.f, // doesn't overflow
	0.0000000001f, 10000000000.f // does overflow
	};
	for (i = 0; i < SK_ARRAY_COUNT(gFloats); i++) {
	test_float_conversions(reporter, gFloats[i]);
	test_float_conversions(reporter, -gFloats[i]);
	}

	for (int outer = 0; outer < 100; outer++) {
	rand.setSeed(outer);
	for (i = 0; i < 100000; i++) {
	float x = nextFloat(rand);
	test_float_conversions(reporter, x);
	}

	test_int2float(reporter, 0);
	test_int2float(reporter, 1);
	test_int2float(reporter, -1);
	for (i = 0; i < 100000; i++) {
	// for now only test ints that are 24bits or less, since we don't
	// round (down) large ints the same as IEEE...
	int ival = rand.nextU() & 0xFFFFFF;
	test_int2float(reporter, ival);
	test_int2float(reporter, -ival);
	}
	}
	}

	#ifdef SK_SCALAR_IS_FLOAT
	static float make_zero() {
	return sk_float_sin(0);
	}
	#endif

	static void unittest_isfinite(skiatest::Reporter* reporter) {
	#ifdef SK_SCALAR_IS_FLOAT
	float nan = sk_float_asin(2);
	float inf = 1.0f / make_zero();
	float big = 3.40282e+038f;

	REPORTER_ASSERT(reporter, !SkScalarIsNaN(inf));
	REPORTER_ASSERT(reporter, !SkScalarIsNaN(-inf));
	REPORTER_ASSERT(reporter, !SkScalarIsFinite(inf));
	REPORTER_ASSERT(reporter, !SkScalarIsFinite(-inf));
	#else
	SkFixed nan = SK_FixedNaN;
	SkFixed big = SK_FixedMax;
	#endif

	REPORTER_ASSERT(reporter, SkScalarIsNaN(nan));
	REPORTER_ASSERT(reporter, !SkScalarIsNaN(big));
	REPORTER_ASSERT(reporter, !SkScalarIsNaN(-big));
	REPORTER_ASSERT(reporter, !SkScalarIsNaN(0));

	REPORTER_ASSERT(reporter, !SkScalarIsFinite(nan));
	REPORTER_ASSERT(reporter, SkScalarIsFinite(big));
	REPORTER_ASSERT(reporter, SkScalarIsFinite(-big));
	REPORTER_ASSERT(reporter, SkScalarIsFinite(0));
	}

	static void test_muldiv255(skiatest::Reporter* reporter) {
	for (int a = 0; a <= 255; a++) {
	for (int b = 0; b <= 255; b++) {
	int ab = a * b;
	float s = ab / 255.0f;
	int round = (int)floorf(s + 0.5f);
	int trunc = (int)floorf(s);

	int iround = SkMulDiv255Round(a, b);
	int itrunc = SkMulDiv255Trunc(a, b);

	REPORTER_ASSERT(reporter, iround == round);
	REPORTER_ASSERT(reporter, itrunc == trunc);

	REPORTER_ASSERT(reporter, itrunc <= iround);
	REPORTER_ASSERT(reporter, iround <= a);
	REPORTER_ASSERT(reporter, iround <= b);
	}
	}
	}

	static void test_muldiv255ceiling(skiatest::Reporter* reporter) {
	for (int c = 0; c <= 255; c++) {
	for (int a = 0; a <= 255; a++) {
	int product = (c * a + 255);
	int expected_ceiling = (product + (product >> 8)) >> 8;
	int webkit_ceiling = (c * a + 254) / 255;
	REPORTER_ASSERT(reporter, expected_ceiling == webkit_ceiling);
	int skia_ceiling = SkMulDiv255Ceiling(c, a);
	REPORTER_ASSERT(reporter, skia_ceiling == webkit_ceiling);
	}
	}
	}

	static void test_copysign(skiatest::Reporter* reporter) {
	static const int32_t gTriples[] = {
	// x, y, expected result
	0, 0, 0,
	0, 1, 0,
	0, -1, 0,
	1, 0, 1,
	1, 1, 1,
	1, -1, -1,
	-1, 0, 1,
	-1, 1, 1,
	-1, -1, -1,
	};
	for (size_t i = 0; i < SK_ARRAY_COUNT(gTriples); i += 3) {
	REPORTER_ASSERT(reporter,
	SkCopySign32(gTriples[i], gTriples[i+1]) == gTriples[i+2]);
	float x = (float)gTriples[i];
	float y = (float)gTriples[i+1];
	float expected = (float)gTriples[i+2];
	REPORTER_ASSERT(reporter, sk_float_copysign(x, y) == expected);
	}

	SkRandom rand;
	for (int j = 0; j < 1000; j++) {
	int ix = rand.nextS();
	REPORTER_ASSERT(reporter, SkCopySign32(ix, ix) == ix);
	REPORTER_ASSERT(reporter, SkCopySign32(ix, -ix) == -ix);
	REPORTER_ASSERT(reporter, SkCopySign32(-ix, ix) == ix);
	REPORTER_ASSERT(reporter, SkCopySign32(-ix, -ix) == -ix);

	SkScalar sx = rand.nextSScalar1();
	REPORTER_ASSERT(reporter, SkScalarCopySign(sx, sx) == sx);
	REPORTER_ASSERT(reporter, SkScalarCopySign(sx, -sx) == -sx);
	REPORTER_ASSERT(reporter, SkScalarCopySign(-sx, sx) == sx);
	REPORTER_ASSERT(reporter, SkScalarCopySign(-sx, -sx) == -sx);
	}
	}

	static void TestMath(skiatest::Reporter* reporter) {
	int i;
	int32_t x;
	SkRandom rand;

	// these should assert
	#if 0
	SkToS8(128);
	SkToS8(-129);
	SkToU8(256);
	SkToU8(-5);

	SkToS16(32768);
	SkToS16(-32769);
	SkToU16(65536);
	SkToU16(-5);

	if (sizeof(size_t) > 4) {
	SkToS32(410241024);
	SkToS32(-410241024);
	SkToU32(510241024);
	SkToU32(-5);
	}
	#endif

	test_muldiv255(reporter);
	test_muldiv255ceiling(reporter);
	test_copysign(reporter);

	{
	SkScalar x = SK_ScalarNaN;
	REPORTER_ASSERT(reporter, SkScalarIsNaN(x));
	}

	for (i = 1; i <= 10; i++) {
	x = SkCubeRootBits(iii, 11);
	REPORTER_ASSERT(reporter, x == i);
	}

	x = SkFixedSqrt(SK_Fixed1);
	REPORTER_ASSERT(reporter, x == SK_Fixed1);
	x = SkFixedSqrt(SK_Fixed1/4);
	REPORTER_ASSERT(reporter, x == SK_Fixed1/2);
	x = SkFixedSqrt(SK_Fixed1*4);
	REPORTER_ASSERT(reporter, x == SK_Fixed1*2);

	x = SkFractSqrt(SK_Fract1);
	REPORTER_ASSERT(reporter, x == SK_Fract1);
	x = SkFractSqrt(SK_Fract1/4);
	REPORTER_ASSERT(reporter, x == SK_Fract1/2);
	x = SkFractSqrt(SK_Fract1/16);
	REPORTER_ASSERT(reporter, x == SK_Fract1/4);

	for (i = 1; i < 100; i++) {
	x = SkFixedSqrt(SK_Fixed1 * i * i);
	REPORTER_ASSERT(reporter, x == SK_Fixed1 * i);
	}

	for (i = 0; i < 1000; i++) {
	int value = rand.nextS16();
	int max = rand.nextU16();

	int clamp = SkClampMax(value, max);
	int clamp2 = value < 0 ? 0 : (value > max ? max : value);
	REPORTER_ASSERT(reporter, clamp == clamp2);
	}

	for (i = 0; i < 10000; i++) {
	SkPoint p;

	// These random values are being treated as 32-bit-patterns, not as
	// ints; calling SkIntToScalar() here produces crashes.
	p.setLength((SkScalar) rand.nextS(),
	(SkScalar) rand.nextS(),
	SK_Scalar1);
	check_length(reporter, p, SK_Scalar1);
	p.setLength((SkScalar) (rand.nextS() >> 13),
	(SkScalar) (rand.nextS() >> 13),
	SK_Scalar1);
	check_length(reporter, p, SK_Scalar1);
	}

	{
	SkFixed result = SkFixedDiv(100, 100);
	REPORTER_ASSERT(reporter, result == SK_Fixed1);
	result = SkFixedDiv(1, SK_Fixed1);
	REPORTER_ASSERT(reporter, result == 1);
	}

	unittest_fastfloat(reporter);
	unittest_isfinite(reporter);

	#ifdef SkLONGLONG
	for (i = 0; i < 10000; i++) {
	SkFixed numer = rand.nextS();
	SkFixed denom = rand.nextS();
	SkFixed result = SkFixedDiv(numer, denom);
	SkLONGLONG check = ((SkLONGLONG)numer << 16) / denom;

	(void)SkCLZ(numer);
	(void)SkCLZ(denom);

	REPORTER_ASSERT(reporter, result != (SkFixed)SK_NaN32);
	if (check > SK_MaxS32) {
	check = SK_MaxS32;
	} else if (check < -SK_MaxS32) {
	check = SK_MinS32;
	}
	REPORTER_ASSERT(reporter, result == (int32_t)check);

	result = SkFractDiv(numer, denom);
	check = ((SkLONGLONG)numer << 30) / denom;

	REPORTER_ASSERT(reporter, result != (SkFixed)SK_NaN32);
	if (check > SK_MaxS32) {
	check = SK_MaxS32;
	} else if (check < -SK_MaxS32) {
	check = SK_MinS32;
	}
	REPORTER_ASSERT(reporter, result == (int32_t)check);

	// make them <= 2^24, so we don't overflow in fixmul
	numer = numer << 8 >> 8;
	denom = denom << 8 >> 8;

	result = SkFixedMul(numer, denom);
	SkFixed r2 = symmetric_fixmul(numer, denom);
	// SkASSERT(result == r2);

	result = SkFixedMul(numer, numer);
	r2 = SkFixedSquare(numer);
	REPORTER_ASSERT(reporter, result == r2);

	if (numer >= 0 && denom >= 0) {
	SkFixed mean = SkFixedMean(numer, denom);
	float prod = SkFixedToFloat(numer) * SkFixedToFloat(denom);
	float fm = sk_float_sqrt(sk_float_abs(prod));
	SkFixed mean2 = SkFloatToFixed(fm);
	int diff = SkAbs32(mean - mean2);
	REPORTER_ASSERT(reporter, diff <= 1);
	}

	{
	SkFixed mod = SkFixedMod(numer, denom);
	float n = SkFixedToFloat(numer);
	float d = SkFixedToFloat(denom);
	float m = sk_float_mod(n, d);
	// ensure the same sign
	REPORTER_ASSERT(reporter, mod == 0 \|\| (mod < 0) == (m < 0));
	int diff = SkAbs32(mod - SkFloatToFixed(m));
	REPORTER_ASSERT(reporter, (diff >> 7) == 0);
	}
	}
	#endif

	for (i = 0; i < 10000; i++) {
	SkFract x = rand.nextU() >> 1;
	double xx = (double)x / SK_Fract1;
	SkFract xr = SkFractSqrt(x);
	SkFract check = SkFloatToFract(sqrt(xx));
	REPORTER_ASSERT(reporter, xr == check \|\|
	xr == check-1 \|\|
	xr == check+1);

	xr = SkFixedSqrt(x);
	xx = (double)x / SK_Fixed1;
	check = SkFloatToFixed(sqrt(xx));
	REPORTER_ASSERT(reporter, xr == check \|\| xr == check-1);

	xr = SkSqrt32(x);
	xx = (double)x;
	check = (int32_t)sqrt(xx);
	REPORTER_ASSERT(reporter, xr == check \|\| xr == check-1);
	}

	#if !defined(SK_SCALAR_IS_FLOAT)
	{
	SkFixed s, c;
	s = SkFixedSinCos(0, &c);
	REPORTER_ASSERT(reporter, s == 0);
	REPORTER_ASSERT(reporter, c == SK_Fixed1);
	}

	int maxDiff = 0;
	for (i = 0; i < 1000; i++) {
	SkFixed rads = rand.nextS() >> 10;
	double frads = SkFixedToFloat(rads);

	SkFixed s, c;
	s = SkScalarSinCos(rads, &c);

	double fs = sin(frads);
	double fc = cos(frads);

	SkFixed is = SkFloatToFixed(fs);
	SkFixed ic = SkFloatToFixed(fc);

	maxDiff = SkMax32(maxDiff, SkAbs32(is - s));
	maxDiff = SkMax32(maxDiff, SkAbs32(ic - c));
	}
	SkDebugf("SinCos: maximum error = %d\n", maxDiff);
	#endif

	#ifdef SK_SCALAR_IS_FLOAT
	test_blend(reporter);
	#endif

	if (false) test_floor(reporter);

	// disable for now
	if (false) test_blend31(); // avoid bit rot, suppress warning

	test_muldivround(reporter);
	test_clz(reporter);
	}

	#include "TestClassDef.h"
	DEFINE_TESTCLASS("Math", MathTestClass, TestMath)

	///////////////////////////////////////////////////////////////////////////////

	#include "SkEndian.h"

	template <typename T> struct PairRec {
	T fYin;
	T fYang;
	};

	static void TestEndian(skiatest::Reporter* reporter) {
	static const PairRec<uint16_t> g16[] = {
	{ 0x0, 0x0 },
	{ 0xFFFF, 0xFFFF },
	{ 0x1122, 0x2211 },
	};
	static const PairRec<uint32_t> g32[] = {
	{ 0x0, 0x0 },
	{ 0xFFFFFFFF, 0xFFFFFFFF },
	{ 0x11223344, 0x44332211 },
	};
	static const PairRec<uint64_t> g64[] = {
	{ 0x0, 0x0 },
	{ 0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFFULL },
	{ 0x1122334455667788ULL, 0x8877665544332211ULL },
	};

	REPORTER_ASSERT(reporter, 0x1122 == SkTEndianSwap16<0x2211>::value);
	REPORTER_ASSERT(reporter, 0x11223344 == SkTEndianSwap32<0x44332211>::value);
	REPORTER_ASSERT(reporter, 0x1122334455667788ULL == SkTEndianSwap64<0x8877665544332211ULL>::value);

	for (size_t i = 0; i < SK_ARRAY_COUNT(g16); ++i) {
	REPORTER_ASSERT(reporter, g16[i].fYang == SkEndianSwap16(g16[i].fYin));
	}
	for (size_t i = 0; i < SK_ARRAY_COUNT(g32); ++i) {
	REPORTER_ASSERT(reporter, g32[i].fYang == SkEndianSwap32(g32[i].fYin));
	}
	for (size_t i = 0; i < SK_ARRAY_COUNT(g64); ++i) {
	REPORTER_ASSERT(reporter, g64[i].fYang == SkEndianSwap64(g64[i].fYin));
	}
	}

	DEFINE_TESTCLASS("Endian", EndianTestClass, TestEndian)

	template <typename T>
	static void test_divmod(skiatest::Reporter* r) {
	const struct {
	T numer;
	T denom;
	} kEdgeCases[] = {
	{(T)17, (T)17},
	{(T)17, (T)4},
	{(T)0, (T)17},
	// For unsigned T these negatives are just some large numbers. Doesn't hurt to test them.
	{(T)-17, (T)-17},
	{(T)-17, (T)4},
	{(T)17, (T)-4},
	{(T)-17, (T)-4},
	};

	for (size_t i = 0; i < SK_ARRAY_COUNT(kEdgeCases); i++) {
	const T numer = kEdgeCases[i].numer;
	const T denom = kEdgeCases[i].denom;
	T div, mod;
	SkTDivMod(numer, denom, &div, &mod);
	REPORTER_ASSERT(r, numer/denom == div);
	REPORTER_ASSERT(r, numer%denom == mod);
	}

	SkRandom rand;
	for (size_t i = 0; i < 10000; i++) {
	const T numer = (T)rand.nextS();
	T denom = 0;
	while (0 == denom) {
	denom = (T)rand.nextS();
	}
	T div, mod;
	SkTDivMod(numer, denom, &div, &mod);
	REPORTER_ASSERT(r, numer/denom == div);
	REPORTER_ASSERT(r, numer%denom == mod);
	}
	}

	DEF_TEST(divmod_u8, r) {
	test_divmod<uint8_t>(r);
	}

	DEF_TEST(divmod_u16, r) {
	test_divmod<uint16_t>(r);
	}

	DEF_TEST(divmod_u32, r) {
	test_divmod<uint32_t>(r);
	}

	DEF_TEST(divmod_u64, r) {
	test_divmod<uint64_t>(r);
	}

	DEF_TEST(divmod_s8, r) {
	test_divmod<int8_t>(r);
	}

	DEF_TEST(divmod_s16, r) {
	test_divmod<int16_t>(r);
	}

	DEF_TEST(divmod_s32, r) {
	test_divmod<int32_t>(r);
	}

	DEF_TEST(divmod_s64, r) {
	test_divmod<int64_t>(r);
	}