SkRasterPipeline: 8x pipelines

Bench runtime changes:
sRGB: 7194 -> 3735  = 1.93x faster 
F16:  6531 -> 2559  = 2.55x faster

Instead of building 4x and 1-3x pipelines and then maybe 8x and 1-7x, instead build either the short ones or the long ones, but not both.  If we just take care to use a compatible run_pipeline(), there's some cross-module type disagreement but everything works out in the end.

Oddly, a few places that looked like they'd be faster using SkNx_fma() or Sk4f_round()/Sk8f_round() are actually faster the long way, e.g. multiply, add 0.5, truncate.  Curious!  In all the other places you see here that I've used SkNx_fma(), it's been a significant speedup.

This folds in a couple refactors and cleanups that I've been meaning to do.  Hope you don't mind... if find the new code considerably easier to read than the old code.

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2990
CQ_INCLUDE_TRYBOTS=master.client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot

Change-Id: I1c82e5755d8e44cc0b9c6673d04b117f85d71a3a
Reviewed-on: https://skia-review.googlesource.com/2990
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/src/core/SkHalf.h b/src/core/SkHalf.h
index dd978a2347..e71cb8750a 100644
--- a/src/core/SkHalf.h
+++ b/src/core/SkHalf.h
@@ -11,6 +11,10 @@
 #include "SkNx.h"
 #include "SkTypes.h"
 
+#if !defined(_MSC_VER) && SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_AVX2
+    #include <x86intrin.h>
+#endif
+
 // 16-bit floating point value
 // format is 1 bit sign, 5 bits exponent, 10 bits mantissa
 // only used for storage
@@ -85,4 +89,29 @@ static inline Sk4h SkFloatToHalf_finite_ftz(const Sk4f& fs) {
 #endif
 }
 
+static inline Sk8f SkHalfToFloat_finite_ftz(const Sk8h& hs) {
+#if !defined(SKNX_NO_SIMD) && SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_AVX2
+    return _mm256_cvtph_ps(hs.fVec);
+
+#else
+    uint64_t parts[2];
+    hs.store(parts);
+    return SkNx_join(SkHalfToFloat_finite_ftz(parts[0]),
+                     SkHalfToFloat_finite_ftz(parts[1]));
+
+#endif
+}
+
+static inline Sk8h SkFloatToHalf_finite_ftz(const Sk8f& fs) {
+#if !defined(SKNX_NO_SIMD) && SK_CPU_SSE_LEVEL >= SK_CPU_SSE_LEVEL_AVX2
+    return _mm256_cvtps_ph(fs.fVec, _MM_FROUND_CUR_DIRECTION);
+
+#else
+    uint64_t parts[2];
+    SkFloatToHalf_finite_ftz(fs.fLo).store(parts+0);
+    SkFloatToHalf_finite_ftz(fs.fHi).store(parts+1);
+    return Sk8h::Load(parts);
+#endif
+}
+
 #endif