Sk2x::invert() and Sk2x::approxInvert()

src/opts/Sk2x_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.
  */
 
 // It is important _not_ to put header guards here.
 // This file will be intentionally included three times.
 
@@ skipping 20 matching lines @@
 #define M(...) template <> inline __VA_ARGS__ Sk2x<float>::
 
 M() Sk2x() {}
 M() Sk2x(float val)        { fVec = vdup_n_f32(val);    }
 M() Sk2x(float a, float b) { fVec = (float32x2_t) { a, b }; }
 M(Sk2f&) operator=(const Sk2f& o) { fVec = o.fVec; return *this; }
 
 M(Sk2f) Load(const float vals[2]) { return vld1_f32(vals); }
 M(void) store(float vals[2]) const { vst1_f32(vals, fVec); }
 
+M(Sk2f) approxInvert() const {
+    float32x2_t est0 = vrecpe_f32(fVec),
+                est1 = vmul_f32(vrecps_f32(est0, fVec), est0);
+    return est1;
+}
+
+M(Sk2f) invert() const {
+    float32x2_t est1 = this->approxInvert().fVec,
+                est2 = vmul_f32(vrecps_f32(est1, fVec), est1);
+    return est2;
+}
+
 M(Sk2f)      add(const Sk2f& o) const { return vadd_f32(fVec, o.fVec); }
 M(Sk2f) subtract(const Sk2f& o) const { return vsub_f32(fVec, o.fVec); }
 M(Sk2f) multiply(const Sk2f& o) const { return vmul_f32(fVec, o.fVec); }
 M(Sk2f)   divide(const Sk2f& o) const {
 #if defined(SK_CPU_ARM64)
     return vdiv_f32(fVec, o.fVec);
 #else
-    float32x2_t est0 = vrecpe_f32(o.fVec),
-                est1 = vmul_f32(vrecps_f32(est0, o.fVec), est0),
-                est2 = vmul_f32(vrecps_f32(est1, o.fVec), est1);
-    return vmul_f32(est2, fVec);
+    return vmul_f32(fVec, o.invert().fVec);
 #endif
 }
 
 M(Sk2f) Min(const Sk2f& a, const Sk2f& b) { return vmin_f32(a.fVec, b.fVec); }
 M(Sk2f) Max(const Sk2f& a, const Sk2f& b) { return vmax_f32(a.fVec, b.fVec); }
 
 M(Sk2f) rsqrt() const {
     float32x2_t est0 = vrsqrte_f32(fVec),
                 est1 = vmul_f32(vrsqrts_f32(fVec, vmul_f32(est0, est0)), est0);
     return est1;
@@ skipping 30 matching lines @@
     M(Sk2d) Min(const Sk2d& a, const Sk2d& b) { return vminq_f64(a.fVec, b.fVec); }
     M(Sk2d) Max(const Sk2d& a, const Sk2d& b) { return vmaxq_f64(a.fVec, b.fVec); }
 
     M(Sk2d) rsqrt() const {
         float64x2_t est0 = vrsqrteq_f64(fVec),
                     est1 = vmulq_f64(vrsqrtsq_f64(fVec, vmulq_f64(est0, est0)), est0);
         return est1;
     }
     M(Sk2d)  sqrt() const { return vsqrtq_f64(fVec); }
 
+    M(Sk2d) approxInvert() const {
+        float64x2_t est0 = vrecpeq_f64(fVec),
+                    est1 = vmulq_f64(vrecpsq_f64(est0, fVec), est0);
+        return est1;
+    }
+
+    M(Sk2d) invert() const {
+        float64x2_t est1 = this->approxInvert().fVec,
+                    est2 = vmulq_f64(vrecpsq_f64(est1, fVec), est1),
+                    est3 = vmulq_f64(vrecpsq_f64(est2, fVec), est2);
+        return est3;
+    }
+
 #else  // Scalar implementation for 32-bit chips, which don't have float64x2_t.
     M() Sk2x() {}
     M() Sk2x(double val)         { fVec[0] = fVec[1] = val; }
     M() Sk2x(double a, double b) { fVec[0] = a; fVec[1] = b; }
     M(Sk2d&) operator=(const Sk2d& o) {
         fVec[0] = o.fVec[0];
         fVec[1] = o.fVec[1];
         return *this;
     }
 
     M(Sk2d) Load(const double vals[2]) { return Sk2d(vals[0], vals[1]); }
     M(void) store(double vals[2]) const { vals[0] = fVec[0]; vals[1] = fVec[1]; }
 
     M(Sk2d)      add(const Sk2d& o) const { return Sk2d(fVec[0] + o.fVec[0], fVec[1] + o.fVec[1]); }
     M(Sk2d) subtract(const Sk2d& o) const { return Sk2d(fVec[0] - o.fVec[0], fVec[1] - o.fVec[1]); }
     M(Sk2d) multiply(const Sk2d& o) const { return Sk2d(fVec[0] * o.fVec[0], fVec[1] * o.fVec[1]); }
     M(Sk2d)   divide(const Sk2d& o) const { return Sk2d(fVec[0] / o.fVec[0], fVec[1] / o.fVec[1]); }
 
     M(Sk2d) Min(const Sk2d& a, const Sk2d& b) {
         return Sk2d(SkTMin(a.fVec[0], b.fVec[0]), SkTMin(a.fVec[1], b.fVec[1]));
     }
     M(Sk2d) Max(const Sk2d& a, const Sk2d& b) {
         return Sk2d(SkTMax(a.fVec[0], b.fVec[0]), SkTMax(a.fVec[1], b.fVec[1]));
     }
 
     M(Sk2d) rsqrt() const { return Sk2d(1.0/::sqrt(fVec[0]), 1.0/::sqrt(fVec[1])); }
     M(Sk2d)  sqrt() const { return Sk2d(    ::sqrt(fVec[0]),     ::sqrt(fVec[1])); }
+
+    M(Sk2d)       invert() const { return Sk2d(1.0 / fVec[0], 1.0 / fVec[1]); }
+    M(Sk2d) approxInvert() const { return this->invert(); }
 #endif
 
 #undef M
 
 #endif