Vectorized bihash_{48,40,24,16}_8 key compare

bihash_48_8 case:
Scalar code: 6 clocks
SSE4.2 code: 3 clocks
AVX2 code: 2.27 clocks
AVX512 code: 1.5 clocks

Change-Id: I40700175835a1e7321276e47eadbf9771d3c5a68
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vppinfra/vector_avx2.h b/src/vppinfra/vector_avx2.h
index e2d5701..6dd110c 100644
--- a/src/vppinfra/vector_avx2.h
+++ b/src/vppinfra/vector_avx2.h
@@ -64,29 +64,34 @@
   return (u32x8) _mm256_permutevar8x32_epi32 ((__m256i) v, (__m256i) idx);
 }
 
-always_inline u32x4
-u32x8_extract_lo (u32x8 v)
-{
-  return (u32x4) _mm256_extracti128_si256 ((__m256i) v, 0);
-}
+/* _extract_lo, _extract_hi */
+/* *INDENT-OFF* */
+#define _(t1,t2) \
+always_inline t1							\
+t2##_extract_lo (t2 v)							\
+{ return (t1) _mm256_extracti128_si256 ((__m256i) v, 0); }		\
+\
+always_inline t1							\
+t2##_extract_hi (t2 v)							\
+{ return (t1) _mm256_extracti128_si256 ((__m256i) v, 1); }		\
+\
+always_inline t2							\
+t2##_insert_lo (t2 v1, t1 v2)						\
+{ return (t2) _mm256_inserti128_si256 ((__m256i) v1, (__m128i) v2, 0); }\
+\
+always_inline t2							\
+t2##_insert_hi (t2 v1, t1 v2)						\
+{ return (t2) _mm256_inserti128_si256 ((__m256i) v1, (__m128i) v2, 1); }\
 
-always_inline u32x4
-u32x8_extract_hi (u32x8 v)
-{
-  return (u32x4) _mm256_extracti128_si256 ((__m256i) v, 1);
-}
+_(u8x16, u8x32)
+_(u16x8, u16x16)
+_(u32x4, u32x8)
+_(u64x2, u64x4)
+#undef _
+/* *INDENT-ON* */
 
-always_inline u32x8
-u32x8_insert_lo (u32x8 v1, u32x4 v2)
-{
-  return (u32x8) _mm256_inserti128_si256 ((__m256i) v1, (__m128i) v2, 0);
-}
 
-always_inline u32x8
-u32x8_insert_hi (u32x8 v1, u32x4 v2)
-{
-  return (u32x8) _mm256_inserti128_si256 ((__m256i) v1, (__m128i) v2, 1);
-}
+
 
 static_always_inline u32
 u8x32_msb_mask (u8x32 v)