acl: introduce DFA nodes compression (group64) for identical entries

[dpdk.git] / lib / librte_acl / acl_run_scalar.c

diff --git a/lib/librte_acl/acl_run_scalar.c b/lib/librte_acl/acl_run_scalar.c
index 43c8fc3..40691ce 100644 (file)
--- a/lib/librte_acl/acl_run_scalar.c
+++ b/lib/librte_acl/acl_run_scalar.c
@@ -94,15 +94,6 @@ resolve_priority_scalar(uint64_t transition, int n,
        }
 }
 
-/*
- * When processing the transition, rather than using if/else
- * construct, the offset is calculated for DFA and QRANGE and
- * then conditionally added to the address based on node type.
- * This is done to avoid branch mis-predictions. Since the
- * offset is rather simple calculation it is more efficient
- * to do the calculation and do a condition move rather than
- * a conditional branch to determine which calculation to do.
- */
 static inline uint32_t
 scan_forward(uint32_t input, uint32_t max)
 {
@@ -117,18 +108,27 @@ scalar_transition(const uint64_t *trans_table, uint64_t transition,
 
        /* break transition into component parts */
        ranges = transition >> (sizeof(index) * CHAR_BIT);
-
-       /* calc address for a QRANGE node */
-       c = input * SCALAR_QRANGE_MULT;
-       a = ranges | SCALAR_QRANGE_MIN;
        index = transition & ~RTE_ACL_NODE_INDEX;
-       a -= (c & SCALAR_QRANGE_MASK);
-       b = c & SCALAR_QRANGE_MIN;
        addr = transition ^ index;
-       a &= SCALAR_QRANGE_MIN;
-       a ^= (ranges ^ b) & (a ^ b);
-       x = scan_forward(a, 32) >> 3;
-       addr += (index == RTE_ACL_NODE_DFA) ? input : x;
+
+       if (index != RTE_ACL_NODE_DFA) {
+               /* calc address for a QRANGE/SINGLE node */
+               c = (uint32_t)input * SCALAR_QRANGE_MULT;
+               a = ranges | SCALAR_QRANGE_MIN;
+               a -= (c & SCALAR_QRANGE_MASK);
+               b = c & SCALAR_QRANGE_MIN;
+               a &= SCALAR_QRANGE_MIN;
+               a ^= (ranges ^ b) & (a ^ b);
+               x = scan_forward(a, 32) >> 3;
+       } else {
+               /* calc address for a DFA node */
+               x = ranges >> (input /
+                       RTE_ACL_DFA_GR64_SIZE * RTE_ACL_DFA_GR64_BIT);
+               x &= UINT8_MAX;
+               x = input - x;
+       }
+
+       addr += x;
 
        /* pickup next transition */
        transition = *(trans_table + addr);