+ #elif defined(USE_MMX)
+ constexpr IndexType kNumChunks = kInputDimensions / kSimdWidth;
+ const __m64 k0x80s = _mm_set1_pi8(-128);
+ const auto in = reinterpret_cast<const __m64*>(input);
+ const auto out = reinterpret_cast<__m64*>(output);
+ for (IndexType i = 0; i < kNumChunks; ++i) {
+ const __m64 words0 = _mm_srai_pi16(
+ _mm_packs_pi32(in[i * 4 + 0], in[i * 4 + 1]),
+ kWeightScaleBits);
+ const __m64 words1 = _mm_srai_pi16(
+ _mm_packs_pi32(in[i * 4 + 2], in[i * 4 + 3]),
+ kWeightScaleBits);
+ const __m64 packedbytes = _mm_packs_pi16(words0, words1);
+ out[i] = _mm_subs_pi8(_mm_adds_pi8(packedbytes, k0x80s), k0x80s);
+ }
+ _mm_empty();
+ constexpr IndexType kStart = kNumChunks * kSimdWidth;
+