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

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "Sk4px.h"
 #include "SkNx.h"
 #include "SkRandom.h"
 #include "Test.h"

 template <int N>
 static void test_Nf(skiatest::Reporter* r) {

     auto assert_nearly_eq = [&](float eps, const SkNx<N, float>& v,
                                 float a, float b, float c, float d) {
         auto close = [=](float a, float b) { return fabsf(a-b) <= eps; };
         float vals[4];
         v.store(vals);
         bool ok = close(vals[0], a) && close(vals[1], b)
                && close(   v[0], a) && close(   v[1], b);
         REPORTER_ASSERT(r, ok);
         if (N == 4) {
             ok = close(vals[2], c) && close(vals[3], d)
               && close(   v[2], c) && close(   v[3], d);
             REPORTER_ASSERT(r, ok);
         }
     };
     auto assert_eq = [&](const SkNx<N, float>& v, float a, float b, float c, float d) {
         return assert_nearly_eq(0, v, a,b,c,d);
     };

     float vals[] = {3, 4, 5, 6};
     SkNx<N,float> a = SkNx<N,float>::Load(vals),
                   b(a),
                   c = a;
     SkNx<N,float> d;
     d = a;

     assert_eq(a, 3, 4, 5, 6);
     assert_eq(b, 3, 4, 5, 6);
     assert_eq(c, 3, 4, 5, 6);
     assert_eq(d, 3, 4, 5, 6);

     assert_eq(a+b, 6, 8, 10, 12);
     assert_eq(a*b, 9, 16, 25, 36);
     assert_eq(a*b-b, 6, 12, 20, 30);
     assert_eq((a*b).sqrt(), 3, 4, 5, 6);
     assert_eq(a/b, 1, 1, 1, 1);
     assert_eq(SkNx<N,float>(0)-a, -3, -4, -5, -6);

     SkNx<N,float> fours(4);

     assert_eq(fours.sqrt(), 2,2,2,2);
     assert_nearly_eq(0.001f, fours.rsqrt(), 0.5, 0.5, 0.5, 0.5);

     assert_nearly_eq(0.001f, fours.invert(), 0.25, 0.25, 0.25, 0.25);

     assert_eq(SkNx<N,float>::Min(a, fours), 3, 4, 4, 4);
     assert_eq(SkNx<N,float>::Max(a, fours), 4, 4, 5, 6);

     // Test some comparisons.  This is not exhaustive.
     REPORTER_ASSERT(r, (a == b).allTrue());
     REPORTER_ASSERT(r, (a+b == a*b-b).anyTrue());
     REPORTER_ASSERT(r, !(a+b == a*b-b).allTrue());
     REPORTER_ASSERT(r, !(a+b == a*b).anyTrue());
     REPORTER_ASSERT(r, !(a != b).anyTrue());
     REPORTER_ASSERT(r, (a < fours).anyTrue());
     REPORTER_ASSERT(r, (a <= fours).anyTrue());
     REPORTER_ASSERT(r, !(a > fours).allTrue());
     REPORTER_ASSERT(r, !(a >= fours).allTrue());
 }

 DEF_TEST(SkNf, r) {
     test_Nf<2>(r);
     test_Nf<4>(r);
 }

 template <int N, typename T>
 void test_Ni(skiatest::Reporter* r) {
     auto assert_eq = [&](const SkNx<N,T>& v, T a, T b, T c, T d, T e, T f, T g, T h) {
         T vals[8];
         v.store(vals);

         switch (N) {
           case 8: REPORTER_ASSERT(r, vals[4] == e && vals[5] == f && vals[6] == g && vals[7] == h);
           case 4: REPORTER_ASSERT(r, vals[2] == c && vals[3] == d);
           case 2: REPORTER_ASSERT(r, vals[0] == a && vals[1] == b);
         }
         switch (N) {
           case 8: REPORTER_ASSERT(r, v[4] == e && v[5] == f &&
                                      v[6] == g && v[7] == h);
           case 4: REPORTER_ASSERT(r, v[2] == c && v[3] == d);
           case 2: REPORTER_ASSERT(r, v[0] == a && v[1] == b);
         }
     };

     T vals[] = { 1,2,3,4,5,6,7,8 };
     SkNx<N,T> a = SkNx<N,T>::Load(vals),
               b(a),
               c = a;
     SkNx<N,T> d;
     d = a;

     assert_eq(a, 1,2,3,4,5,6,7,8);
     assert_eq(b, 1,2,3,4,5,6,7,8);
     assert_eq(c, 1,2,3,4,5,6,7,8);
     assert_eq(d, 1,2,3,4,5,6,7,8);

     assert_eq(a+a, 2,4,6,8,10,12,14,16);
     assert_eq(a*a, 1,4,9,16,25,36,49,64);
     assert_eq(a*a-a, 0,2,6,12,20,30,42,56);

     assert_eq(a >> 2, 0,0,0,1,1,1,1,2);
     assert_eq(a << 1, 2,4,6,8,10,12,14,16);

     REPORTER_ASSERT(r, a[1] == 2);
 }

 DEF_TEST(SkNx, r) {
     test_Ni<2, uint16_t>(r);
     test_Ni<4, uint16_t>(r);
     test_Ni<8, uint16_t>(r);

     test_Ni<2, int>(r);
     test_Ni<4, int>(r);
     test_Ni<8, int>(r);
 }

 DEF_TEST(SkNi_min_lt, r) {
     // Exhaustively check the 8x8 bit space.
     for (int a = 0; a < (1<<8); a++) {
     for (int b = 0; b < (1<<8); b++) {
         Sk16b aw(a), bw(b);
         REPORTER_ASSERT(r, Sk16b::Min(aw, bw)[0] == SkTMin(a, b));
         REPORTER_ASSERT(r, !(aw < bw)[0] == !(a < b));
     }}

     // Exhausting the 16x16 bit space is kind of slow, so only do that in release builds.
 #ifdef SK_DEBUG
     SkRandom rand;
     for (int i = 0; i < (1<<16); i++) {
         uint16_t a = rand.nextU() >> 16,
                  b = rand.nextU() >> 16;
         REPORTER_ASSERT(r, Sk16h::Min(Sk16h(a), Sk16h(b))[0] == SkTMin(a, b));
     }
 #else
     for (int a = 0; a < (1<<16); a++) {
     for (int b = 0; b < (1<<16); b++) {
         REPORTER_ASSERT(r, Sk16h::Min(Sk16h(a), Sk16h(b))[0] == SkTMin(a, b));
     }}
 #endif
 }

 DEF_TEST(SkNi_saturatedAdd, r) {
     for (int a = 0; a < (1<<8); a++) {
     for (int b = 0; b < (1<<8); b++) {
         int exact = a+b;
         if (exact > 255) { exact = 255; }
         if (exact <   0) { exact =   0; }

         REPORTER_ASSERT(r, Sk16b(a).saturatedAdd(Sk16b(b))[0] == exact);
     }
     }
 }

 DEF_TEST(Sk4px_muldiv255round, r) {
     for (int a = 0; a < (1<<8); a++) {
     for (int b = 0; b < (1<<8); b++) {
         int exact = (a*b+127)/255;

         // Duplicate a and b 16x each.
         auto av = Sk4px::DupAlpha(a),
              bv = Sk4px::DupAlpha(b);

         // This way should always be exactly correct.
         int correct = (av * bv).div255()[0];
         REPORTER_ASSERT(r, correct == exact);

         // We're a bit more flexible on this method: correct for 0 or 255, otherwise off by <=1.
         int fast = av.approxMulDiv255(bv)[0];
         REPORTER_ASSERT(r, fast-exact >= -1 && fast-exact <= 1);
         if (a == 0 || a == 255 || b == 0 || b == 255) {
             REPORTER_ASSERT(r, fast == exact);
         }
     }
     }
 }

 DEF_TEST(Sk4px_widening, r) {
     SkPMColor colors[] = {
         SkPreMultiplyColor(0xff00ff00),
         SkPreMultiplyColor(0x40008000),
         SkPreMultiplyColor(0x7f020406),
         SkPreMultiplyColor(0x00000000),
     };
     auto packed = Sk4px::Load4(colors);

     auto wideLo = packed.widenLo(),
          wideHi = packed.widenHi(),
          wideLoHi    = packed.widenLoHi(),
          wideLoHiAlt = wideLo + wideHi;
     REPORTER_ASSERT(r, 0 == memcmp(&wideLoHi, &wideLoHiAlt, sizeof(wideLoHi)));
 }

 DEF_TEST(SkNx_abs, r) {
     auto fs = Sk4f(0.0f, -0.0f, 2.0f, -4.0f).abs();
     REPORTER_ASSERT(r, fs[0] == 0.0f);
     REPORTER_ASSERT(r, fs[1] == 0.0f);
     REPORTER_ASSERT(r, fs[2] == 2.0f);
     REPORTER_ASSERT(r, fs[3] == 4.0f);
 }

 DEF_TEST(SkNx_floor, r) {
     auto fs = Sk4f(0.4f, -0.4f, 0.6f, -0.6f).floor();
     REPORTER_ASSERT(r, fs[0] ==  0.0f);
     REPORTER_ASSERT(r, fs[1] == -1.0f);
     REPORTER_ASSERT(r, fs[2] ==  0.0f);
     REPORTER_ASSERT(r, fs[3] == -1.0f);
 }

 DEF_TEST(SkNx_shuffle, r) {
     Sk4f f4(0,10,20,30);

     Sk2f f2 = SkNx_shuffle<2,1>(f4);
     REPORTER_ASSERT(r, f2[0] == 20);
     REPORTER_ASSERT(r, f2[1] == 10);

     f4 = SkNx_shuffle<0,1,1,0>(f2);
     REPORTER_ASSERT(r, f4[0] == 20);
     REPORTER_ASSERT(r, f4[1] == 10);
     REPORTER_ASSERT(r, f4[2] == 10);
     REPORTER_ASSERT(r, f4[3] == 20);
 }

 DEF_TEST(SkNx_int_float, r) {
     Sk4f f(-2.3f, 1.0f, 0.45f, 0.6f);

     Sk4i i = SkNx_cast<int>(f);
     REPORTER_ASSERT(r, i[0] == -2);
     REPORTER_ASSERT(r, i[1] ==  1);
     REPORTER_ASSERT(r, i[2] ==  0);
     REPORTER_ASSERT(r, i[3] ==  0);

     f = SkNx_cast<float>(i);
     REPORTER_ASSERT(r, f[0] == -2.0f);
     REPORTER_ASSERT(r, f[1] ==  1.0f);
     REPORTER_ASSERT(r, f[2] ==  0.0f);
     REPORTER_ASSERT(r, f[3] ==  0.0f);
 }

 #include "SkRandom.h"

 DEF_TEST(SkNx_u16_float, r) {
     {
         // u16 --> float
         auto h4 = Sk4h(15, 17, 257, 65535);
         auto f4 = SkNx_cast<float>(h4);
         REPORTER_ASSERT(r, f4[0] == 15.0f);
         REPORTER_ASSERT(r, f4[1] == 17.0f);
         REPORTER_ASSERT(r, f4[2] == 257.0f);
         REPORTER_ASSERT(r, f4[3] == 65535.0f);
     }
     {
         // float -> u16
         auto f4 = Sk4f(15, 17, 257, 65535);
         auto h4 = SkNx_cast<uint16_t>(f4);
         REPORTER_ASSERT(r, h4[0] == 15);
         REPORTER_ASSERT(r, h4[1] == 17);
         REPORTER_ASSERT(r, h4[2] == 257);
         REPORTER_ASSERT(r, h4[3] == 65535);
     }

     // starting with any u16 value, we should be able to have a perfect round-trip in/out of floats
     //
     SkRandom rand;
     for (int i = 0; i < 10000; ++i) {
         const uint16_t s16[4] {
             (uint16_t)rand.nextU16(), (uint16_t)rand.nextU16(),
             (uint16_t)rand.nextU16(), (uint16_t)rand.nextU16(),
         };
         auto u4_0 = Sk4h::Load(s16);
         auto f4 = SkNx_cast<float>(u4_0);
         auto u4_1 = SkNx_cast<uint16_t>(f4);
         uint16_t d16[4];
         u4_1.store(d16);
         REPORTER_ASSERT(r, !memcmp(s16, d16, sizeof(s16)));
     }
 }

 // The SSE2 implementation of SkNx_cast<uint16_t>(Sk4i) is non-trivial, so worth a test.
 DEF_TEST(SkNx_int_u16, r) {
     // These are pretty hard to get wrong.
     for (int i = 0; i <= 0x7fff; i++) {
         uint16_t expected = (uint16_t)i;
         uint16_t actual = SkNx_cast<uint16_t>(Sk4i(i))[0];

         REPORTER_ASSERT(r, expected == actual);
     }

     // A naive implementation with _mm_packs_epi32 would succeed up to 0x7fff but fail here:
     for (int i = 0x8000; (1) && i <= 0xffff; i++) {
         uint16_t expected = (uint16_t)i;
         uint16_t actual = SkNx_cast<uint16_t>(Sk4i(i))[0];

         REPORTER_ASSERT(r, expected == actual);
     }
 }

 DEF_TEST(SkNx_4fLoad4Store4, r) {
     float src[] = {
          0.0f,  1.0f,  2.0f,  3.0f,
          4.0f,  5.0f,  6.0f,  7.0f,
          8.0f,  9.0f, 10.0f, 11.0f,
         12.0f, 13.0f, 14.0f, 15.0f
     };

     Sk4f a, b, c, d;
     Sk4f::Load4(src, &a, &b, &c, &d);
     REPORTER_ASSERT(r,  0.0f == a[0]);
     REPORTER_ASSERT(r,  4.0f == a[1]);
     REPORTER_ASSERT(r,  8.0f == a[2]);
     REPORTER_ASSERT(r, 12.0f == a[3]);
     REPORTER_ASSERT(r,  1.0f == b[0]);
     REPORTER_ASSERT(r,  5.0f == b[1]);
     REPORTER_ASSERT(r,  9.0f == b[2]);
     REPORTER_ASSERT(r, 13.0f == b[3]);
     REPORTER_ASSERT(r,  2.0f == c[0]);
     REPORTER_ASSERT(r,  6.0f == c[1]);
     REPORTER_ASSERT(r, 10.0f == c[2]);
     REPORTER_ASSERT(r, 14.0f == c[3]);
     REPORTER_ASSERT(r,  3.0f == d[0]);
     REPORTER_ASSERT(r,  7.0f == d[1]);
     REPORTER_ASSERT(r, 11.0f == d[2]);
     REPORTER_ASSERT(r, 15.0f == d[3]);

     float dst[16];
     Sk4f::Store4(dst, a, b, c, d);
     REPORTER_ASSERT(r, 0 == memcmp(dst, src, 16 * sizeof(float)));
 }
	/*
	* Copyright 2015 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "Sk4px.h"
	#include "SkNx.h"
	#include "SkRandom.h"
	#include "Test.h"

	template <int N>
	static void test_Nf(skiatest::Reporter* r) {

	auto assert_nearly_eq = [&](float eps, const SkNx<N, float>& v,
	float a, float b, float c, float d) {
	auto close = [=](float a, float b) { return fabsf(a-b) <= eps; };
	float vals[4];
	v.store(vals);
	bool ok = close(vals[0], a) && close(vals[1], b)
	&& close( v[0], a) && close( v[1], b);
	REPORTER_ASSERT(r, ok);
	if (N == 4) {
	ok = close(vals[2], c) && close(vals[3], d)
	&& close( v[2], c) && close( v[3], d);
	REPORTER_ASSERT(r, ok);
	}
	};
	auto assert_eq = [&](const SkNx<N, float>& v, float a, float b, float c, float d) {
	return assert_nearly_eq(0, v, a,b,c,d);
	};

	float vals[] = {3, 4, 5, 6};
	SkNx<N,float> a = SkNx<N,float>::Load(vals),
	b(a),
	c = a;
	SkNx<N,float> d;
	d = a;

	assert_eq(a, 3, 4, 5, 6);
	assert_eq(b, 3, 4, 5, 6);
	assert_eq(c, 3, 4, 5, 6);
	assert_eq(d, 3, 4, 5, 6);

	assert_eq(a+b, 6, 8, 10, 12);
	assert_eq(a*b, 9, 16, 25, 36);
	assert_eq(a*b-b, 6, 12, 20, 30);
	assert_eq((a*b).sqrt(), 3, 4, 5, 6);
	assert_eq(a/b, 1, 1, 1, 1);
	assert_eq(SkNx<N,float>(0)-a, -3, -4, -5, -6);

	SkNx<N,float> fours(4);

	assert_eq(fours.sqrt(), 2,2,2,2);
	assert_nearly_eq(0.001f, fours.rsqrt(), 0.5, 0.5, 0.5, 0.5);

	assert_nearly_eq(0.001f, fours.invert(), 0.25, 0.25, 0.25, 0.25);

	assert_eq(SkNx<N,float>::Min(a, fours), 3, 4, 4, 4);
	assert_eq(SkNx<N,float>::Max(a, fours), 4, 4, 5, 6);

	// Test some comparisons. This is not exhaustive.
	REPORTER_ASSERT(r, (a == b).allTrue());
	REPORTER_ASSERT(r, (a+b == a*b-b).anyTrue());
	REPORTER_ASSERT(r, !(a+b == a*b-b).allTrue());
	REPORTER_ASSERT(r, !(a+b == a*b).anyTrue());
	REPORTER_ASSERT(r, !(a != b).anyTrue());
	REPORTER_ASSERT(r, (a < fours).anyTrue());
	REPORTER_ASSERT(r, (a <= fours).anyTrue());
	REPORTER_ASSERT(r, !(a > fours).allTrue());
	REPORTER_ASSERT(r, !(a >= fours).allTrue());
	}

	DEF_TEST(SkNf, r) {
	test_Nf<2>(r);
	test_Nf<4>(r);
	}

	template <int N, typename T>
	void test_Ni(skiatest::Reporter* r) {
	auto assert_eq = [&](const SkNx<N,T>& v, T a, T b, T c, T d, T e, T f, T g, T h) {
	T vals[8];
	v.store(vals);

	switch (N) {
	case 8: REPORTER_ASSERT(r, vals[4] == e && vals[5] == f && vals[6] == g && vals[7] == h);
	case 4: REPORTER_ASSERT(r, vals[2] == c && vals[3] == d);
	case 2: REPORTER_ASSERT(r, vals[0] == a && vals[1] == b);
	}
	switch (N) {
	case 8: REPORTER_ASSERT(r, v[4] == e && v[5] == f &&
	v[6] == g && v[7] == h);
	case 4: REPORTER_ASSERT(r, v[2] == c && v[3] == d);
	case 2: REPORTER_ASSERT(r, v[0] == a && v[1] == b);
	}
	};

	T vals[] = { 1,2,3,4,5,6,7,8 };
	SkNx<N,T> a = SkNx<N,T>::Load(vals),
	b(a),
	c = a;
	SkNx<N,T> d;
	d = a;

	assert_eq(a, 1,2,3,4,5,6,7,8);
	assert_eq(b, 1,2,3,4,5,6,7,8);
	assert_eq(c, 1,2,3,4,5,6,7,8);
	assert_eq(d, 1,2,3,4,5,6,7,8);

	assert_eq(a+a, 2,4,6,8,10,12,14,16);
	assert_eq(a*a, 1,4,9,16,25,36,49,64);
	assert_eq(a*a-a, 0,2,6,12,20,30,42,56);

	assert_eq(a >> 2, 0,0,0,1,1,1,1,2);
	assert_eq(a << 1, 2,4,6,8,10,12,14,16);

	REPORTER_ASSERT(r, a[1] == 2);
	}

	DEF_TEST(SkNx, r) {
	test_Ni<2, uint16_t>(r);
	test_Ni<4, uint16_t>(r);
	test_Ni<8, uint16_t>(r);

	test_Ni<2, int>(r);
	test_Ni<4, int>(r);
	test_Ni<8, int>(r);
	}

	DEF_TEST(SkNi_min_lt, r) {
	// Exhaustively check the 8x8 bit space.
	for (int a = 0; a < (1<<8); a++) {
	for (int b = 0; b < (1<<8); b++) {
	Sk16b aw(a), bw(b);
	REPORTER_ASSERT(r, Sk16b::Min(aw, bw)[0] == SkTMin(a, b));
	REPORTER_ASSERT(r, !(aw < bw)[0] == !(a < b));
	}}

	// Exhausting the 16x16 bit space is kind of slow, so only do that in release builds.
	#ifdef SK_DEBUG
	SkRandom rand;
	for (int i = 0; i < (1<<16); i++) {
	uint16_t a = rand.nextU() >> 16,
	b = rand.nextU() >> 16;
	REPORTER_ASSERT(r, Sk16h::Min(Sk16h(a), Sk16h(b))[0] == SkTMin(a, b));
	}
	#else
	for (int a = 0; a < (1<<16); a++) {
	for (int b = 0; b < (1<<16); b++) {
	REPORTER_ASSERT(r, Sk16h::Min(Sk16h(a), Sk16h(b))[0] == SkTMin(a, b));
	}}
	#endif
	}

	DEF_TEST(SkNi_saturatedAdd, r) {
	for (int a = 0; a < (1<<8); a++) {
	for (int b = 0; b < (1<<8); b++) {
	int exact = a+b;
	if (exact > 255) { exact = 255; }
	if (exact < 0) { exact = 0; }

	REPORTER_ASSERT(r, Sk16b(a).saturatedAdd(Sk16b(b))[0] == exact);
	}
	}
	}

	DEF_TEST(Sk4px_muldiv255round, r) {
	for (int a = 0; a < (1<<8); a++) {
	for (int b = 0; b < (1<<8); b++) {
	int exact = (a*b+127)/255;

	// Duplicate a and b 16x each.
	auto av = Sk4px::DupAlpha(a),
	bv = Sk4px::DupAlpha(b);

	// This way should always be exactly correct.
	int correct = (av * bv).div255()[0];
	REPORTER_ASSERT(r, correct == exact);

	// We're a bit more flexible on this method: correct for 0 or 255, otherwise off by <=1.
	int fast = av.approxMulDiv255(bv)[0];
	REPORTER_ASSERT(r, fast-exact >= -1 && fast-exact <= 1);
	if (a == 0 \|\| a == 255 \|\| b == 0 \|\| b == 255) {
	REPORTER_ASSERT(r, fast == exact);
	}
	}
	}
	}

	DEF_TEST(Sk4px_widening, r) {
	SkPMColor colors[] = {
	SkPreMultiplyColor(0xff00ff00),
	SkPreMultiplyColor(0x40008000),
	SkPreMultiplyColor(0x7f020406),
	SkPreMultiplyColor(0x00000000),
	};
	auto packed = Sk4px::Load4(colors);

	auto wideLo = packed.widenLo(),
	wideHi = packed.widenHi(),
	wideLoHi = packed.widenLoHi(),
	wideLoHiAlt = wideLo + wideHi;
	REPORTER_ASSERT(r, 0 == memcmp(&wideLoHi, &wideLoHiAlt, sizeof(wideLoHi)));
	}

	DEF_TEST(SkNx_abs, r) {
	auto fs = Sk4f(0.0f, -0.0f, 2.0f, -4.0f).abs();
	REPORTER_ASSERT(r, fs[0] == 0.0f);
	REPORTER_ASSERT(r, fs[1] == 0.0f);
	REPORTER_ASSERT(r, fs[2] == 2.0f);
	REPORTER_ASSERT(r, fs[3] == 4.0f);
	}

	DEF_TEST(SkNx_floor, r) {
	auto fs = Sk4f(0.4f, -0.4f, 0.6f, -0.6f).floor();
	REPORTER_ASSERT(r, fs[0] == 0.0f);
	REPORTER_ASSERT(r, fs[1] == -1.0f);
	REPORTER_ASSERT(r, fs[2] == 0.0f);
	REPORTER_ASSERT(r, fs[3] == -1.0f);
	}

	DEF_TEST(SkNx_shuffle, r) {
	Sk4f f4(0,10,20,30);

	Sk2f f2 = SkNx_shuffle<2,1>(f4);
	REPORTER_ASSERT(r, f2[0] == 20);
	REPORTER_ASSERT(r, f2[1] == 10);

	f4 = SkNx_shuffle<0,1,1,0>(f2);
	REPORTER_ASSERT(r, f4[0] == 20);
	REPORTER_ASSERT(r, f4[1] == 10);
	REPORTER_ASSERT(r, f4[2] == 10);
	REPORTER_ASSERT(r, f4[3] == 20);
	}

	DEF_TEST(SkNx_int_float, r) {
	Sk4f f(-2.3f, 1.0f, 0.45f, 0.6f);

	Sk4i i = SkNx_cast<int>(f);
	REPORTER_ASSERT(r, i[0] == -2);
	REPORTER_ASSERT(r, i[1] == 1);
	REPORTER_ASSERT(r, i[2] == 0);
	REPORTER_ASSERT(r, i[3] == 0);

	f = SkNx_cast<float>(i);
	REPORTER_ASSERT(r, f[0] == -2.0f);
	REPORTER_ASSERT(r, f[1] == 1.0f);
	REPORTER_ASSERT(r, f[2] == 0.0f);
	REPORTER_ASSERT(r, f[3] == 0.0f);
	}

	#include "SkRandom.h"

	DEF_TEST(SkNx_u16_float, r) {
	{
	// u16 --> float
	auto h4 = Sk4h(15, 17, 257, 65535);
	auto f4 = SkNx_cast<float>(h4);
	REPORTER_ASSERT(r, f4[0] == 15.0f);
	REPORTER_ASSERT(r, f4[1] == 17.0f);
	REPORTER_ASSERT(r, f4[2] == 257.0f);
	REPORTER_ASSERT(r, f4[3] == 65535.0f);
	}
	{
	// float -> u16
	auto f4 = Sk4f(15, 17, 257, 65535);
	auto h4 = SkNx_cast<uint16_t>(f4);
	REPORTER_ASSERT(r, h4[0] == 15);
	REPORTER_ASSERT(r, h4[1] == 17);
	REPORTER_ASSERT(r, h4[2] == 257);
	REPORTER_ASSERT(r, h4[3] == 65535);
	}

	// starting with any u16 value, we should be able to have a perfect round-trip in/out of floats
	//
	SkRandom rand;
	for (int i = 0; i < 10000; ++i) {
	const uint16_t s16[4] {
	(uint16_t)rand.nextU16(), (uint16_t)rand.nextU16(),
	(uint16_t)rand.nextU16(), (uint16_t)rand.nextU16(),
	};
	auto u4_0 = Sk4h::Load(s16);
	auto f4 = SkNx_cast<float>(u4_0);
	auto u4_1 = SkNx_cast<uint16_t>(f4);
	uint16_t d16[4];
	u4_1.store(d16);
	REPORTER_ASSERT(r, !memcmp(s16, d16, sizeof(s16)));
	}
	}

	// The SSE2 implementation of SkNx_cast<uint16_t>(Sk4i) is non-trivial, so worth a test.
	DEF_TEST(SkNx_int_u16, r) {
	// These are pretty hard to get wrong.
	for (int i = 0; i <= 0x7fff; i++) {
	uint16_t expected = (uint16_t)i;
	uint16_t actual = SkNx_cast<uint16_t>(Sk4i(i))[0];

	REPORTER_ASSERT(r, expected == actual);
	}

	// A naive implementation with _mm_packs_epi32 would succeed up to 0x7fff but fail here:
	for (int i = 0x8000; (1) && i <= 0xffff; i++) {
	uint16_t expected = (uint16_t)i;
	uint16_t actual = SkNx_cast<uint16_t>(Sk4i(i))[0];

	REPORTER_ASSERT(r, expected == actual);
	}
	}

	DEF_TEST(SkNx_4fLoad4Store4, r) {
	float src[] = {
	0.0f, 1.0f, 2.0f, 3.0f,
	4.0f, 5.0f, 6.0f, 7.0f,
	8.0f, 9.0f, 10.0f, 11.0f,
	12.0f, 13.0f, 14.0f, 15.0f
	};

	Sk4f a, b, c, d;
	Sk4f::Load4(src, &a, &b, &c, &d);
	REPORTER_ASSERT(r, 0.0f == a[0]);
	REPORTER_ASSERT(r, 4.0f == a[1]);
	REPORTER_ASSERT(r, 8.0f == a[2]);
	REPORTER_ASSERT(r, 12.0f == a[3]);
	REPORTER_ASSERT(r, 1.0f == b[0]);
	REPORTER_ASSERT(r, 5.0f == b[1]);
	REPORTER_ASSERT(r, 9.0f == b[2]);
	REPORTER_ASSERT(r, 13.0f == b[3]);
	REPORTER_ASSERT(r, 2.0f == c[0]);
	REPORTER_ASSERT(r, 6.0f == c[1]);
	REPORTER_ASSERT(r, 10.0f == c[2]);
	REPORTER_ASSERT(r, 14.0f == c[3]);
	REPORTER_ASSERT(r, 3.0f == d[0]);
	REPORTER_ASSERT(r, 7.0f == d[1]);
	REPORTER_ASSERT(r, 11.0f == d[2]);
	REPORTER_ASSERT(r, 15.0f == d[3]);

	float dst[16];
	Sk4f::Store4(dst, a, b, c, d);
	REPORTER_ASSERT(r, 0 == memcmp(dst, src, 16 * sizeof(float)));
	}