summaryrefslogtreecommitdiffstats
path: root/plugins/ioam-plugin/ioam/lib-pot/math64.h
diff options
context:
space:
mode:
Diffstat (limited to 'plugins/ioam-plugin/ioam/lib-pot/math64.h')
-rw-r--r--plugins/ioam-plugin/ioam/lib-pot/math64.h159
1 files changed, 0 insertions, 159 deletions
diff --git a/plugins/ioam-plugin/ioam/lib-pot/math64.h b/plugins/ioam-plugin/ioam/lib-pot/math64.h
deleted file mode 100644
index 4c608a37de4..00000000000
--- a/plugins/ioam-plugin/ioam/lib-pot/math64.h
+++ /dev/null
@@ -1,159 +0,0 @@
-/*
- * math64.h provides the 64 bit unsigned integer add, multiply followed by modulo operation
- * The linux/math64.h provides divide and multiply 64 bit integers but:
- * 1. multiply: mul_u64_u64_shr - only returns 64 bits of the result and has to be called
- * twice to get the complete 128 bits of the result.
- * 2. Modulo operation of the result of addition and multiplication of u64 that may result
- * in integers > 64 bits is not supported
- * Hence this header to combine add/multiply followed by modulo of u64 integrers
- * always resulting in u64.
- *
- * Copyright (c) 2016 Cisco and/or its affiliates.
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-#ifndef include_vnet_math64_h
-#define include_vnet_math64_h
-#include <stdint.h>
-
-/*
- * multiplies and returns result in hi and lo
- */
-static inline void mul64by64(u64 a, u64 b, u64 * hi, u64 * lo)
-{
- u64 a_lo = (u64) (uint32_t) a;
- u64 a_hi = a >> 32;
- u64 b_lo = (u64) (u32) b;
- u64 b_hi = b >> 32;
-
- u64 p0 = a_lo * b_lo;
- u64 p1 = a_lo * b_hi;
- u64 p2 = a_hi * b_lo;
- u64 p3 = a_hi * b_hi;
-
- u32 cy = (u32) (((p0 >> 32) + (u32) p1 + (u32) p2) >> 32);
-
- *lo = p0 + (p1 << 32) + (p2 << 32);
- *hi = p3 + (p1 >> 32) + (p2 >> 32) + cy;
- return;
-}
-
-#define TWO64 18446744073709551616.0
-
-static inline u64 mod128by64(u64 x, u64 y, u64 m, double di)
-{
- u64 q1, q2, q;
- u64 p1, p0;
- double dq;
-
- /* calculate quotient first pass 53 bits */
- dq = (TWO64 * (double)x + (double)y) * di;
-
- if (dq >= TWO64)
- q1 = 0xfffffffffffff800L;
- else
- q1 = dq;
-
- /* q1 * m to compare the product to the dividend. */
- mul64by64(q1, m, &p1, &p0);
-
- /* Adjust quotient. is it > actual result: */
- if (x < p1 || (x == p1 && y < p0))
- {
- /* q1 > quotient. calculate abs remainder */
- x = p1 - (x + (p0 < y));
- y = p0 - y;
-
- /* use the remainder as new dividend to adjust quotient */
- q2 = (u64) ((TWO64 * (double)x + (double)y) * di);
- mul64by64(q2, m, &p1, &p0);
-
- q = q1 - q2;
- if (x < p1 || (x == p1 && y <= p0))
- {
- y = p0 - y;
- }
- else
- {
- y = p0 - y;
- y += m;
- q--;
- }
- }
- else
- {
- x = x - (p1 + (y < p0));
- y = y - p0;
-
- q2 = (u64) ((TWO64 * (double)x + (double)y) * di);
- mul64by64(q2, m, &p1, &p0);
-
- q = q1 + q2;
- if (x < p1 || (x == p1 && y < p0))
- {
- y = y - p0;
- y += m;
- q--;
- }
- else
- {
- y = y - p0;
- if (y >= m)
- {
- y -= m;
- q++;
- }
- }
- }
-
- return y;
-}
-
-/*
- * returns a % p
- */
-static inline u64 mod64by64(u64 a, u64 p, u64 primeinv)
-{
- return (mod128by64(0, a, p, primeinv));
-}
-
-static inline void add64(u64 a, u64 b, u64 * whi, u64 * wlo)
-{
- *wlo = a + b;
- if (*wlo < a)
- *whi = 1;
-
-}
-
-/*
- * returns (a + b)%p
- */
-static inline u64 add64_mod(u64 a, u64 b, u64 p, double pi)
-{
- u64 shi = 0, slo = 0;
-
- add64(a, b, &shi, &slo);
- return (mod128by64(shi, slo, p, pi));
-}
-
-/*
- * returns (ab) % p
- */
-static inline u64 mul64_mod(u64 a, u64 b, u64 p, double pi)
-{
- u64 phi = 0, plo = 0;
-
- mul64by64(a, b, &phi, &plo);
- return (mod128by64(phi, plo, p, pi));
-}
-
-#endif