Update 4-at-a-time APIs.

src/opts/SkPMFloat_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.
+ */
+
 inline SkPMFloat& SkPMFloat::operator=(const SkPMFloat& that) {
     fColors = that.fColors;
     return *this;
 }
 
 // For SkPMFloat(SkPMFColor), we widen our 8 bit components (fix8) to 8-bit components in 16 bits
 // (fix8_16), then widen those to 8-bit-in-32-bits (fix8_32), and finally convert those to floats.
 
 // get() and clamped() do the opposite, working from floats to 8-bit-in-32-bit,
 // to 8-bit-in-16-bit, back down to 8-bit components.
@@ skipping 23 matching lines @@
     float32x4_t add_half = vaddq_f32(fColors, vdupq_n_f32(0.5f));
     uint32x4_t  fix8_32  = vcvtq_u32_f32(add_half);  // vcvtq_u32_f32 truncates, so round manually
     uint16x4_t  fix8_16  = vqmovn_u32(fix8_32);
     uint8x8_t   fix8     = vqmovn_u16(vcombine_u16(fix8_16, vdup_n_u16(0)));
     SkPMColor c = vget_lane_u32((uint32x2_t)fix8, 0);
     SkPMColorAssert(c);
     return c;
 }
 
 // TODO: we should be able to beat these loops on all three methods.
-inline void SkPMFloat::From4PMColors(SkPMFloat floats[4], const SkPMColor colors[4]) {
-    for (int i = 0; i < 4; i++) { floats[i] = FromPMColor(colors[i]); }
+inline void SkPMFloat::From4PMColors(const SkPMColor colors[4],
+                                     SkPMFloat* a, SkPMFloat* b, SkPMFloat* c, SkPMFloat* d) {
+    *a = FromPMColor(colors[0]);
+    *b = FromPMColor(colors[1]);
+    *c = FromPMColor(colors[2]);
+    *d = FromPMColor(colors[3]);
 }
 
-inline void SkPMFloat::To4PMColors(SkPMColor colors[4], const SkPMFloat floats[4]) {
-    for (int i = 0; i < 4; i++) { colors[i] = floats[i].get(); }
+inline void SkPMFloat::To4PMColors(
+        const SkPMFloat& a, const SkPMFloat& b, const SkPMFloat&c, const SkPMFloat& d,
+        SkPMColor colors[4]) {
+    colors[0] = a.get();
+    colors[1] = b.get();
+    colors[2] = c.get();
+    colors[3] = d.get();
 }
 
-inline void SkPMFloat::ClampTo4PMColors(SkPMColor colors[4], const SkPMFloat floats[4]) {
-    for (int i = 0; i < 4; i++) { colors[i] = floats[i].clamped(); }
+inline void SkPMFloat::ClampTo4PMColors(
+        const SkPMFloat& a, const SkPMFloat& b, const SkPMFloat&c, const SkPMFloat& d,
+        SkPMColor colors[4]) {
+    colors[0] = a.clamped();
+    colors[1] = b.clamped();
+    colors[2] = c.clamped();
+    colors[3] = d.clamped();
 }