X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;ds=sidebyside;f=lib%2Flibrte_eal%2Fcommon%2Finclude%2Frte_reciprocal.h;h=63e16fde0aa864f4c5a9777e67d715269d39bc82;hb=df3ff6be2b33faea3edf3c112b9bdc5b74d6f684;hp=5e21f096fa8d808d80df1a8753ad07955c487070;hpb=0b037e8b02b7ced8c18a650b708f2fd6e3364d83;p=dpdk.git

diff --git a/lib/librte_eal/common/include/rte_reciprocal.h b/lib/librte_eal/common/include/rte_reciprocal.h
index 5e21f096fa..63e16fde0a 100644
--- a/lib/librte_eal/common/include/rte_reciprocal.h
+++ b/lib/librte_eal/common/include/rte_reciprocal.h
@@ -1,3 +1,6 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2017 Cavium, Inc
+ */
 /*
  * Reciprocal divide
  *
@@ -29,6 +32,11 @@ struct rte_reciprocal {
 	uint8_t sh1, sh2;
 };
 
+struct rte_reciprocal_u64 {
+	uint64_t m;
+	uint8_t sh1, sh2;
+};
+
 static inline uint32_t rte_reciprocal_divide(uint32_t a, struct rte_reciprocal R)
 {
 	uint32_t t = (uint32_t)(((uint64_t)a * R.m) >> 32);
@@ -36,6 +44,47 @@ static inline uint32_t rte_reciprocal_divide(uint32_t a, struct rte_reciprocal R
 	return (t + ((a - t) >> R.sh1)) >> R.sh2;
 }
 
+static __rte_always_inline uint64_t
+mullhi_u64(uint64_t x, uint64_t y)
+{
+#ifdef __SIZEOF_INT128__
+	__uint128_t xl = x;
+	__uint128_t rl = xl * y;
+
+	return (rl >> 64);
+#else
+	uint64_t u0, u1, v0, v1, k, t;
+	uint64_t w1, w2;
+	uint64_t whi;
+
+	u1 = x >> 32; u0 = x & 0xFFFFFFFF;
+	v1 = y >> 32; v0 = y & 0xFFFFFFFF;
+
+	t = u0*v0;
+	k = t >> 32;
+
+	t = u1*v0 + k;
+	w1 = t & 0xFFFFFFFF;
+	w2 = t >> 32;
+
+	t = u0*v1 + w1;
+	k = t >> 32;
+
+	whi = u1*v1 + w2 + k;
+
+	return whi;
+#endif
+}
+
+static __rte_always_inline uint64_t
+rte_reciprocal_divide_u64(uint64_t a, const struct rte_reciprocal_u64 *R)
+{
+	uint64_t t = mullhi_u64(a, R->m);
+
+	return (t + ((a - t) >> R->sh1)) >> R->sh2;
+}
+
 struct rte_reciprocal rte_reciprocal_value(uint32_t d);
+struct rte_reciprocal_u64 rte_reciprocal_value_u64(uint64_t d);
 
 #endif /* _RTE_RECIPROCAL_H_ */