SkPMFloat::trunc()

src/opts/SkPMFloat_SSE2.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;
@@ skipping 23 matching lines @@
 inline SkPMColor SkPMFloat::clamped() const {
     // We don't use _mm_cvtps_epi32, because we want precise control over how 0.5 rounds (up).
     __m128i fix8_32 = _mm_cvttps_epi32(_mm_add_ps(_mm_set1_ps(0.5f), fColors)),
             fix8_16 = _mm_packus_epi16(fix8_32, fix8_32),
             fix8    = _mm_packus_epi16(fix8_16, fix8_16);
     SkPMColor c = _mm_cvtsi128_si32(fix8);
     SkPMColorAssert(c);
     return c;
 }
 
+inline SkPMColor SkPMFloat::trunc() const {
+    // Basically, same as clamped(), but no rounding.
+    __m128i fix8_32 = _mm_cvttps_epi32(fColors),
+            fix8_16 = _mm_packus_epi16(fix8_32, fix8_32),
+            fix8    = _mm_packus_epi16(fix8_16, fix8_16);
+    SkPMColor c = _mm_cvtsi128_si32(fix8);
+    SkPMColorAssert(c);
+    return c;
+}
+
 inline void SkPMFloat::From4PMColors(const SkPMColor colors[4],
                                      SkPMFloat* a, SkPMFloat* b, SkPMFloat* c, SkPMFloat* d) {
     // Haven't beaten this yet.
     *a = FromPMColor(colors[0]);
     *b = FromPMColor(colors[1]);
     *c = FromPMColor(colors[2]);
     *d = FromPMColor(colors[3]);
 }
 
 inline void SkPMFloat::To4PMColors(
@@ skipping 13 matching lines @@
             c2 = _mm_cvttps_epi32(_mm_add_ps(_mm_set1_ps(0.5f), c.fColors)),
             c3 = _mm_cvttps_epi32(_mm_add_ps(_mm_set1_ps(0.5f), d.fColors));
     __m128i c3210 = _mm_packus_epi16(_mm_packus_epi16(c0, c1),
                                      _mm_packus_epi16(c2, c3));
     _mm_storeu_si128((__m128i*)colors, c3210);
     SkPMColorAssert(colors[0]);
     SkPMColorAssert(colors[1]);
     SkPMColorAssert(colors[2]);
     SkPMColorAssert(colors[3]);
 }