+/*
+ * We group consecutive packets with the same destionation port into one burst.
+ * To avoid extra latency this is done together with some other packet
+ * processing, but after we made a final decision about packet's destination.
+ * To do this we maintain:
+ * pnum - array of number of consecutive packets with the same dest port for
+ * each packet in the input burst.
+ * lp - pointer to the last updated element in the pnum.
+ * dlp - dest port value lp corresponds to.
+ */
+
+#define GRPSZ (1 << FWDSTEP)
+#define GRPMSK (GRPSZ - 1)
+
+#define GROUP_PORT_STEP(dlp, dcp, lp, pn, idx) do { \
+ if (likely((dlp) == (dcp)[(idx)])) { \
+ (lp)[0]++; \
+ } else { \
+ (dlp) = (dcp)[idx]; \
+ (lp) = (pn) + (idx); \
+ (lp)[0] = 1; \
+ } \
+} while (0)
+
+/*
+ * Group consecutive packets with the same destination port in bursts of 4.
+ * Suppose we have array of destionation ports:
+ * dst_port[] = {a, b, c, d,, e, ... }
+ * dp1 should contain: <a, b, c, d>, dp2: <b, c, d, e>.
+ * We doing 4 comparisions at once and the result is 4 bit mask.
+ * This mask is used as an index into prebuild array of pnum values.
+ */
+static inline uint16_t *
+port_groupx4(uint16_t pn[FWDSTEP + 1], uint16_t *lp, __m128i dp1, __m128i dp2)
+{
+ static const struct {
+ uint64_t pnum; /* prebuild 4 values for pnum[]. */
+ int32_t idx; /* index for new last updated elemnet. */
+ uint16_t lpv; /* add value to the last updated element. */
+ } gptbl[GRPSZ] = {
+ {
+ /* 0: a != b, b != c, c != d, d != e */
+ .pnum = UINT64_C(0x0001000100010001),
+ .idx = 4,
+ .lpv = 0,
+ },
+ {
+ /* 1: a == b, b != c, c != d, d != e */
+ .pnum = UINT64_C(0x0001000100010002),
+ .idx = 4,
+ .lpv = 1,
+ },
+ {
+ /* 2: a != b, b == c, c != d, d != e */
+ .pnum = UINT64_C(0x0001000100020001),
+ .idx = 4,
+ .lpv = 0,
+ },
+ {
+ /* 3: a == b, b == c, c != d, d != e */
+ .pnum = UINT64_C(0x0001000100020003),
+ .idx = 4,
+ .lpv = 2,
+ },
+ {
+ /* 4: a != b, b != c, c == d, d != e */
+ .pnum = UINT64_C(0x0001000200010001),
+ .idx = 4,
+ .lpv = 0,
+ },
+ {
+ /* 5: a == b, b != c, c == d, d != e */
+ .pnum = UINT64_C(0x0001000200010002),
+ .idx = 4,
+ .lpv = 1,
+ },
+ {
+ /* 6: a != b, b == c, c == d, d != e */
+ .pnum = UINT64_C(0x0001000200030001),
+ .idx = 4,
+ .lpv = 0,
+ },
+ {
+ /* 7: a == b, b == c, c == d, d != e */
+ .pnum = UINT64_C(0x0001000200030004),
+ .idx = 4,
+ .lpv = 3,
+ },
+ {
+ /* 8: a != b, b != c, c != d, d == e */
+ .pnum = UINT64_C(0x0002000100010001),
+ .idx = 3,
+ .lpv = 0,
+ },
+ {
+ /* 9: a == b, b != c, c != d, d == e */
+ .pnum = UINT64_C(0x0002000100010002),
+ .idx = 3,
+ .lpv = 1,
+ },
+ {
+ /* 0xa: a != b, b == c, c != d, d == e */
+ .pnum = UINT64_C(0x0002000100020001),
+ .idx = 3,
+ .lpv = 0,
+ },
+ {
+ /* 0xb: a == b, b == c, c != d, d == e */
+ .pnum = UINT64_C(0x0002000100020003),
+ .idx = 3,
+ .lpv = 2,
+ },
+ {
+ /* 0xc: a != b, b != c, c == d, d == e */
+ .pnum = UINT64_C(0x0002000300010001),
+ .idx = 2,
+ .lpv = 0,
+ },
+ {
+ /* 0xd: a == b, b != c, c == d, d == e */
+ .pnum = UINT64_C(0x0002000300010002),
+ .idx = 2,
+ .lpv = 1,
+ },
+ {
+ /* 0xe: a != b, b == c, c == d, d == e */
+ .pnum = UINT64_C(0x0002000300040001),
+ .idx = 1,
+ .lpv = 0,
+ },
+ {
+ /* 0xf: a == b, b == c, c == d, d == e */
+ .pnum = UINT64_C(0x0002000300040005),
+ .idx = 0,
+ .lpv = 4,
+ },
+ };
+
+ union {
+ uint16_t u16[FWDSTEP + 1];
+ uint64_t u64;
+ } *pnum = (void *)pn;
+
+ int32_t v;
+
+ dp1 = _mm_cmpeq_epi16(dp1, dp2);
+ dp1 = _mm_unpacklo_epi16(dp1, dp1);
+ v = _mm_movemask_ps((__m128)dp1);
+
+ /* update last port counter. */
+ lp[0] += gptbl[v].lpv;
+
+ /* if dest port value has changed. */
+ if (v != GRPMSK) {
+ lp = pnum->u16 + gptbl[v].idx;
+ lp[0] = 1;
+ pnum->u64 = gptbl[v].pnum;
+ }
+
+ return lp;
+}
+