skeleton for float <-> half optimized procs
Nothing fancy yet, just calls the serial code in a loop.
I will try to folow this up with at least some of:
- SSE2 version of serial code
- NEON version of serial code
- NEON version using vcvt.f32.f16/vcvt.f16.f32
- F16C (between AVX and AVX2) version using vcvtph2ps/vcvtps2ph
The last two are fastest but need runtime detection.
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1686543003
Review URL: https://codereview.chromium.org/1686543003
diff --git a/bench/HalfBench.cpp b/bench/HalfBench.cpp
new file mode 100644
index 0000000..1c76c57
--- /dev/null
+++ b/bench/HalfBench.cpp
@@ -0,0 +1,48 @@
+/*
+ * 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;)
diff --git a/src/core/SkOpts.cpp b/src/core/SkOpts.cpp
index fbc4f6c..7534ac5 100644
--- a/src/core/SkOpts.cpp
+++ b/src/core/SkOpts.cpp
@@ -5,6 +5,7 @@
* found in the LICENSE file.
*/
+#include "SkHalf.h"
#include "SkOnce.h"
#include "SkOpts.h"
@@ -20,6 +21,19 @@
#include "SkUtils_opts.h"
#include "SkXfermode_opts.h"
+namespace SK_OPTS_NS {
+ static void float_to_half(uint16_t dst[], const float src[], int n) {
+ while (n-->0) {
+ *dst++ = SkFloatToHalf(*src++);
+ }
+ }
+ static void half_to_float(float dst[], const uint16_t src[], int n) {
+ while (n-->0) {
+ *dst++ = SkHalfToFloat(*src++);
+ }
+ }
+}
+
#if defined(SK_CPU_X86) && !defined(SK_BUILD_FOR_IOS)
#if defined(SK_BUILD_FOR_WIN32)
#include <intrin.h>
@@ -90,6 +104,9 @@
decltype(inverted_CMYK_to_RGB1) inverted_CMYK_to_RGB1 = sk_default::inverted_CMYK_to_RGB1;
decltype(inverted_CMYK_to_BGR1) inverted_CMYK_to_BGR1 = sk_default::inverted_CMYK_to_BGR1;
+ decltype(half_to_float) half_to_float = sk_default::half_to_float;
+ decltype(float_to_half) float_to_half = sk_default::float_to_half;
+
// Each Init_foo() is defined in src/opts/SkOpts_foo.cpp.
void Init_ssse3();
void Init_sse41();
diff --git a/src/core/SkOpts.h b/src/core/SkOpts.h
index 2e8778e..c717526 100644
--- a/src/core/SkOpts.h
+++ b/src/core/SkOpts.h
@@ -67,6 +67,9 @@
grayA_to_rgbA, // i.e. expand to color channels and premultiply
inverted_CMYK_to_RGB1, // i.e. convert color space
inverted_CMYK_to_BGR1; // i.e. convert color space
+
+ extern void (*half_to_float)(float[], const uint16_t[], int);
+ extern void (*float_to_half)(uint16_t[], const float[], int);
}
#endif//SkOpts_DEFINED
diff --git a/tests/Float16Test.cpp b/tests/Float16Test.cpp
index 0a2c3d5..f437268 100644
--- a/tests/Float16Test.cpp
+++ b/tests/Float16Test.cpp
@@ -8,6 +8,7 @@
#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) {
@@ -50,3 +51,16 @@
}
}
}
+
+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)));
+}