skeleton for float <-> half optimized procs

tests/Float16Test.cpp

 /*
  * Copyright 2016 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 "SkColor.h"
 #include "SkHalf.h"
+#include "SkOpts.h"
 #include "SkPixmap.h"
 
 static bool eq_within_half_float(float a, float b) {
     const float kTolerance = 1.0f / (1 << (8 + 10));
 
     SkHalf ha = SkFloatToHalf(a);
     SkHalf hb = SkFloatToHalf(b);
     float a2 = SkHalfToFloat(ha);
     float b2 = SkHalfToFloat(hb);
     return fabsf(a2 - b2) <= kTolerance;
@@ skipping 22 matching lines @@
     pm.erase(c4);
 
     SkPM4f origpm4 = c4.premul();
     for (int y = 0; y < pm.height(); ++y) {
         for (int x = 0; x < pm.width(); ++x) {
             SkPM4f pm4 = SkPM4f::FromF16(pm.addrF16(x, y));
             REPORTER_ASSERT(reporter, eq_within_half_float(origpm4, pm4));
         }
     }
 }
+
+DEF_TEST(float_to_half, reporter) {
+    const float    fs[] = {    1.0,    2.0,    3.0,    4.0,    5.0,    6.0,    7.0 };
+    const uint16_t hs[] = { 0x3c00, 0x4000, 0x4200, 0x4400, 0x4500, 0x4600, 0x4700 };
+
+    uint16_t hscratch[7];
+    SkOpts::float_to_half(hscratch, fs, 7);
+    REPORTER_ASSERT(reporter, 0 == memcmp(hscratch, hs, sizeof(hs)));
+
+    float fscratch[7];
+    SkOpts::half_to_float(fscratch, hs, 7);
+    REPORTER_ASSERT(reporter, 0 == memcmp(fscratch, fs, sizeof(fs)));
+}