start again on Sk4x with portable version and unit tests

tests/Sk4xTest.cpp

+#include "Test.h"
+#include "Sk4x.h"
+
+#define ASSERT_EQ(a, b) REPORTER_ASSERT(r, a.equal(b).allTrue())
+#define ASSERT_NE(a, b) REPORTER_ASSERT(r, a.notEqual(b).allTrue())
+
+DEF_TEST(Sk4x_Construction, r) {
+    Sk4f uninitialized;
+    Sk4f zero(0,0,0,0);
+    Sk4f foo(1,2,3,4),
+         bar(foo),
+         baz = bar;
+    ASSERT_EQ(foo, bar);
+    ASSERT_EQ(bar, baz);
+    ASSERT_EQ(baz, foo);
+}
+
+DEF_TEST(Sk4x_LoadStore, r) {
+    // fs will be 16-byte aligned, fs+1 not.
+    float fs[] = { 5,6,7,8,9 };
+
+    Sk4f foo = Sk4f::Load(fs);
+    Sk4f bar = Sk4f::LoadAligned(fs);
+    ASSERT_EQ(foo, bar);
+
+    foo = Sk4f::Load(fs+1);
+    ASSERT_NE(foo, bar);
+
+    foo.storeAligned(fs);
+    bar.store(fs+1);
+    REPORTER_ASSERT(r, fs[0] == 6 &&
+                       fs[1] == 5 &&
+                       fs[2] == 6 &&
+                       fs[3] == 7 &&
+                       fs[4] == 8);
+}
+
+DEF_TEST(Sk4x_Conversions, r) {
+    // Assuming IEEE floats.
+    Sk4f zerof(0,0,0,0);
+    Sk4i zeroi(0,0,0,0);
+    ASSERT_EQ(zeroi, zerof.cast<Sk4i>());
+    ASSERT_EQ(zeroi, zerof.reinterpret<Sk4i>());
+
+    Sk4f twof(2,2,2,2);
+    Sk4i twoi(2,2,2,2);
+    ASSERT_EQ(twoi, twof.cast<Sk4i>());
+    ASSERT_NE(twoi, twof.reinterpret<Sk4i>());
+}
+
+DEF_TEST(Sk4x_Bits, r) {
+    ASSERT_EQ(Sk4i(0,0,0,0).bitNot(), Sk4i(-1,-1,-1,-1));
+
+    Sk4i a(2,3,4,5),
+         b(1,3,5,7);
+    ASSERT_EQ(Sk4i(0,3,4,5), a.bitAnd(b));
+    ASSERT_EQ(Sk4i(3,3,5,7), a.bitOr(b));
+}
+
+DEF_TEST(Sk4x_Arith, r) {
+    ASSERT_EQ(Sk4f(4,6,8,10),    Sk4f(1,2,3,4).add(Sk4f(3,4,5,6)));
+    ASSERT_EQ(Sk4f(-2,-2,-2,-2), Sk4f(1,2,3,4).subtract(Sk4f(3,4,5,6)));
+    ASSERT_EQ(Sk4f(3,8,15,24),   Sk4f(1,2,3,4).multiply(Sk4f(3,4,5,6)));
+
+    float third = 1.0f/3.0f;
+    ASSERT_EQ(Sk4f(1*third, 0.5f, 0.6f, 2*third), Sk4f(1,2,3,4).divide(Sk4f(3,4,5,6)));
+}
+
+DEF_TEST(Sk4x_Comparison, r) {
+    ASSERT_EQ(Sk4f(1,2,3,4), Sk4f(1,2,3,4));
+    ASSERT_NE(Sk4f(4,3,2,1), Sk4f(1,2,3,4));
+
+    ASSERT_EQ(Sk4i(-1,-1,0,-1), Sk4f(1,2,5,4).equal(Sk4f(1,2,3,4)));
+
+    ASSERT_EQ(Sk4i(-1,-1,-1,-1), Sk4f(1,2,3,4).lessThan(Sk4f(2,3,4,5)));
+    ASSERT_EQ(Sk4i(-1,-1,-1,-1), Sk4f(1,2,3,4).lessThanEqual(Sk4f(2,3,4,5)));
+    ASSERT_EQ(Sk4i(0,0,0,0),     Sk4f(1,2,3,4).greaterThan(Sk4f(2,3,4,5)));
+    ASSERT_EQ(Sk4i(0,0,0,0),     Sk4f(1,2,3,4).greaterThanEqual(Sk4f(2,3,4,5)));
+}
+
+DEF_TEST(Sk4x_MinMax, r) {
+    ASSERT_EQ(Sk4f(1,2,2,1), Sk4f::Min(Sk4f(1,2,3,4), Sk4f(4,3,2,1)));
+    ASSERT_EQ(Sk4f(4,3,3,4), Sk4f::Max(Sk4f(1,2,3,4), Sk4f(4,3,2,1)));
+}
+
+DEF_TEST(Sk4x_Swizzle, r) {
+    ASSERT_EQ(Sk4f(3,4,1,2), Sk4f(1,2,3,4).zwxy());
+    ASSERT_EQ(Sk4f(1,2,5,6), Sk4f::XYAB(Sk4f(1,2,3,4), Sk4f(5,6,7,8)));
+    ASSERT_EQ(Sk4f(3,4,7,8), Sk4f::ZWCD(Sk4f(1,2,3,4), Sk4f(5,6,7,8)));
+}