Revert of Implement four more xfermodes with Sk4px. (patchset #16 id:290001 of https://codereview.chromium.org/1196713004/)

Reason for revert:
64-bit ARM build failures.

Original issue's description:
> Implement four more xfermodes with Sk4px.
>
> HardLight, Overlay, Darken, and Lighten are all
> ~2x faster with SSE, ~25% faster with NEON.
>
> This covers all previously-implemented NEON xfermodes.
> 3 previous SSE xfermodes remain.  Those need division
> and sqrt, so I'm planning on using SkPMFloat for them.
> It'll help the readability and NEON speed if I move that
> into [0,1] space first.
>
> The main new concept here is c.thenElse(t,e), which behaves like
> (c ? t : e) except, of course, both t and e are evaluated.  This allows
> us to emulate conditionals with vectors.
>
> This also removes the concept of SkNb.  Instead of a standalone bool
> vector, each SkNi or SkNf will just return their own types for
> comparisons.  Turns out to be a lot more manageable this way.
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/b9d4163bebab0f5639f9c5928bb5fc15f472dddc

TBR=reed@google.com,mtklein@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1205703008

1 files changed, 9 insertions, 51 deletions

diff --git a/src/core/Sk4pxXfermode.h b/src/core/Sk4pxXfermode.h
index 09490dc990..b4ebd850e3 100644
--- a/src/core/Sk4pxXfermode.h
+++ b/src/core/Sk4pxXfermode.h
@@ -60,44 +60,6 @@ XFERMODE(Exclusion) {
     return (s - p) + (d - p.zeroAlphas());
 }
 
-XFERMODE(HardLight) {
-    auto alphas = SrcOver::Xfer(s,d);
-
-    auto sa = s.alphas(),
-         da = d.alphas();
-
-    auto isDark = s < (sa-s);
-
-    auto dark = s*d << 1,
-         lite = sa*da - ((da-d)*(sa-s) << 1),
-         both = s*da.inv() + d*sa.inv();
-
-    // TODO: do isDark in 16-bit so we only have to div255() once.
-    auto colors = isDark.thenElse((dark + both).div255(),
-                                  (lite + both).div255());
-    return alphas.zeroColors() + colors.zeroAlphas();
-}
-XFERMODE(Overlay) { return HardLight::Xfer(d,s); }
-
-XFERMODE(Darken) {
-    auto sda = s.approxMulDiv255(d.alphas()),
-         dsa = d.approxMulDiv255(s.alphas());
-    auto srcover = s + (d - dsa),
-         dstover = d + (s - sda);
-    auto alphas = srcover,
-         colors = (sda < dsa).thenElse(srcover, dstover);
-    return alphas.zeroColors() + colors.zeroAlphas();
-}
-XFERMODE(Lighten) {
-    auto sda = s.approxMulDiv255(d.alphas()),
-         dsa = d.approxMulDiv255(s.alphas());
-    auto srcover = s + (d - dsa),
-         dstover = d + (s - sda);
-    auto alphas = srcover,
-         colors = (sda < dsa).thenElse(dstover, srcover);
-    return alphas.zeroColors() + colors.zeroAlphas();
-}
-
 #undef XFERMODE
 
 // A reasonable fallback mode for doing AA is to simply apply the transfermode first,
@@ -109,15 +71,17 @@ static Sk4px xfer_aa(const Sk4px& s, const Sk4px& d, const Sk4px& aa) {
 }
 
 // For some transfermodes we specialize AA, either for correctness or performance.
-#define XFERMODE_AA(Name) \
-    template <> Sk4px xfer_aa<Name>(const Sk4px& s, const Sk4px& d, const Sk4px& aa)
+#ifndef SK_NO_SPECIALIZED_AA_XFERMODES
+    #define XFERMODE_AA(Name) \
+        template <> Sk4px xfer_aa<Name>(const Sk4px& s, const Sk4px& d, const Sk4px& aa)
 
-// Plus' clamp needs to happen after AA.  skia:3852
-XFERMODE_AA(Plus) {  // [ clamp( (1-AA)D + (AA)(S+D) ) == clamp(D + AA*S) ]
-    return d.saturatedAdd(s.approxMulDiv255(aa));
-}
+    // Plus' clamp needs to happen after AA.  skia:3852
+    XFERMODE_AA(Plus) {  // [ clamp( (1-AA)D + (AA)(S+D) ) == clamp(D + AA*S) ]
+        return d.saturatedAdd(s.approxMulDiv255(aa));
+    }
 
-#undef XFERMODE_AA
+    #undef XFERMODE_AA
+#endif
 
 template <typename ProcType>
 class SkT4pxXfermode : public SkProcCoeffXfermode {
@@ -166,12 +130,6 @@ static SkProcCoeffXfermode* SkCreate4pxXfermode(const ProcCoeff& rec, SkXfermode
         case SkXfermode::kMultiply_Mode:   return SkT4pxXfermode<Multiply>::Create(rec);
         case SkXfermode::kDifference_Mode: return SkT4pxXfermode<Difference>::Create(rec);
         case SkXfermode::kExclusion_Mode:  return SkT4pxXfermode<Exclusion>::Create(rec);
-#if !defined(SK_SUPPORT_LEGACY_XFERMODES)  // For staging in Chrome (layout tests).
-        case SkXfermode::kHardLight_Mode:  return SkT4pxXfermode<HardLight>::Create(rec);
-        case SkXfermode::kOverlay_Mode:    return SkT4pxXfermode<Overlay>::Create(rec);
-        case SkXfermode::kDarken_Mode:     return SkT4pxXfermode<Darken>::Create(rec);
-        case SkXfermode::kLighten_Mode:    return SkT4pxXfermode<Lighten>::Create(rec);
-#endif
         default: break;
     }
 #endif