add SkNx::abs(), for now only implemented for Sk4f

src/opts/SkNx_neon.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkNx_neon_DEFINED
 #define SkNx_neon_DEFINED
 
@@ skipping 169 matching lines @@
     SkNx operator >(const SkNx& o) const { return vreinterpretq_f32_u32(vcgtq_f32(fVec, o.fVec)); }
     SkNx operator<=(const SkNx& o) const { return vreinterpretq_f32_u32(vcleq_f32(fVec, o.fVec)); }
     SkNx operator>=(const SkNx& o) const { return vreinterpretq_f32_u32(vcgeq_f32(fVec, o.fVec)); }
     SkNx operator!=(const SkNx& o) const {
         return vreinterpretq_f32_u32(vmvnq_u32(vceqq_f32(fVec, o.fVec)));
     }
 
     static SkNx Min(const SkNx& l, const SkNx& r) { return vminq_f32(l.fVec, r.fVec); }
     static SkNx Max(const SkNx& l, const SkNx& r) { return vmaxq_f32(l.fVec, r.fVec); }
 
+    SkNx abs() const { return vabsq_f32(fVec); }
+
     SkNx rsqrt0() const { return vrsqrteq_f32(fVec); }
     SkNx rsqrt1() const {
         float32x4_t est0 = this->rsqrt0().fVec;
         return vmulq_f32(vrsqrtsq_f32(fVec, vmulq_f32(est0, est0)), est0);
     }
     SkNx rsqrt2() const {
         float32x4_t est1 = this->rsqrt1().fVec;
         return vmulq_f32(vrsqrtsq_f32(fVec, vmulq_f32(est1, est1)), est1);
     }
 
@@ skipping 145 matching lines @@
                                 const Sk4f& a, const Sk4f& b, const Sk4f& c, const Sk4f& d) {
     vst1q_u8(bytes, vuzpq_u8(vuzpq_u8((uint8x16_t)vcvtq_u32_f32(a.fVec),
                                       (uint8x16_t)vcvtq_u32_f32(b.fVec)).val[0],
                              vuzpq_u8((uint8x16_t)vcvtq_u32_f32(c.fVec),
                                       (uint8x16_t)vcvtq_u32_f32(d.fVec)).val[0]).val[0]);
 }
 
 }  // namespace
 
 #endif//SkNx_neon_DEFINED