inline SkPMFloat& SkPMFloat::operator=(const SkPMFloat& that) {
    fColors = that.fColors;
    return *this;
}

// For SkPMFloat(SkPMColor), 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.
// _mm_packus_epi16() gives us clamping for free while narrowing.

inline SkPMFloat::SkPMFloat(SkPMColor c) {
    SkPMColorAssert(c);
    __m128i fix8    = _mm_set_epi32(0,0,0,c),
            fix8_16 = _mm_unpacklo_epi8 (fix8,    _mm_setzero_si128()),
            fix8_32 = _mm_unpacklo_epi16(fix8_16, _mm_setzero_si128());
    fColors = _mm_cvtepi32_ps(fix8_32);
    SkASSERT(this->isValid());
}

inline SkPMColor SkPMFloat::get() const {
    SkASSERT(this->isValid());
    return this->clamped();  // Haven't beaten this yet.
}

inline SkPMColor SkPMFloat::clamped() const {
    __m128i fix8_32 = _mm_cvtps_epi32(fColors),  // _mm_cvtps_epi32 rounds for us!
            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(SkPMFloat floats[4], const SkPMColor colors[4]) {
    // Haven't beaten this yet.
    for (int i = 0; i < 4; i++) { floats[i] = FromPMColor(colors[i]); }
}

inline void SkPMFloat::To4PMColors(SkPMColor colors[4], const SkPMFloat floats[4]) {
    SkASSERT(floats[0].isValid() && floats[1].isValid()
          && floats[2].isValid() && floats[3].isValid());
    // Haven't beaten this yet.
    ClampTo4PMColors(colors, floats);
}

inline void SkPMFloat::ClampTo4PMColors(SkPMColor colors[4], const SkPMFloat floats[4]) {
    // Same as _SSSE3.h's.  We use 3 _mm_packus_epi16() where the naive loop uses 8.
    __m128i c0 = _mm_cvtps_epi32(floats[0].fColors),  // _mm_cvtps_epi32 rounds for us!
            c1 = _mm_cvtps_epi32(floats[1].fColors),
            c2 = _mm_cvtps_epi32(floats[2].fColors),
            c3 = _mm_cvtps_epi32(floats[3].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]);
}