Remove bulk float <-> half routines. These are dead code.

bench/HalfBench.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 "Benchmark.h"
-#include "SkOpts.h"
-#include "SkRandom.h"
-
-struct FloatToHalfBench : public Benchmark {
-    const char* onGetName() override { return "float_to_half"; }
-    bool isSuitableFor(Backend backend) override { return backend == kNonRendering_Backend; }
-
-    void onDraw(int loops, SkCanvas* canvas) override {
-        SkRandom rand;
-        float fs[1023];
-        for (float& f : fs) {
-            f = rand.nextF();
-        }
-
-        uint16_t hs[1023];
-        while (loops --> 0) {
-            SkOpts::float_to_half(hs, fs, 1023);
-        }
-    }
-};
-DEF_BENCH(return new FloatToHalfBench;)
-
-struct HalfToFloatBench : public Benchmark {
-    const char* onGetName() override { return "half_to_float"; }
-    bool isSuitableFor(Backend backend) override { return backend == kNonRendering_Backend; }
-
-    void onDraw(int loops, SkCanvas* canvas) override {
-        SkRandom rand;
-        uint16_t hs[1023];
-        for (uint16_t& h : hs) {
-            h = rand.nextU16();
-        }
-
-        float fs[1023];
-        while (loops --> 0) {
-            SkOpts::half_to_float(fs, hs, 1023);
-        }
-    }
-};
-DEF_BENCH(return new HalfToFloatBench;)