1 /* 2 * 3 * Copyright 2015 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 #ifndef GRPC_CORE_LIB_GPR_USEFUL_H 20 #define GRPC_CORE_LIB_GPR_USEFUL_H 21 22 /** useful macros that don't belong anywhere else */ 23 24 #define GPR_MIN(a, b) ((a) < (b) ? (a) : (b)) 25 #define GPR_MAX(a, b) ((a) > (b) ? (a) : (b)) 26 #define GPR_CLAMP(a, min, max) ((a) < (min) ? (min) : (a) > (max) ? (max) : (a)) 27 /** rotl, rotr assume x is unsigned */ 28 #define GPR_ROTL(x, n) (((x) << (n)) | ((x) >> (sizeof(x) * 8 - (n)))) 29 #define GPR_ROTR(x, n) (((x) >> (n)) | ((x) << (sizeof(x) * 8 - (n)))) 30 31 #define GPR_ARRAY_SIZE(array) (sizeof(array) / sizeof(*(array))) 32 33 #define GPR_SWAP(type, a, b) \ 34 do { \ 35 type x = a; \ 36 a = b; \ 37 b = x; \ 38 } while (0) 39 40 /** Set the \a n-th bit of \a i (a mutable pointer). */ 41 #define GPR_BITSET(i, n) ((*(i)) |= (1u << (n))) 42 43 /** Clear the \a n-th bit of \a i (a mutable pointer). */ 44 #define GPR_BITCLEAR(i, n) ((*(i)) &= ~(1u << (n))) 45 46 /** Get the \a n-th bit of \a i */ 47 #define GPR_BITGET(i, n) (((i) & (1u << (n))) != 0) 48 49 #define GPR_INTERNAL_HEXDIGIT_BITCOUNT(x) \ 50 ((x) - (((x) >> 1) & 0x77777777) - (((x) >> 2) & 0x33333333) - \ 51 (((x) >> 3) & 0x11111111)) 52 53 /** Returns number of bits set in bitset \a i */ 54 #define GPR_BITCOUNT(i) \ 55 (((GPR_INTERNAL_HEXDIGIT_BITCOUNT(i) + \ 56 (GPR_INTERNAL_HEXDIGIT_BITCOUNT(i) >> 4)) & \ 57 0x0f0f0f0f) % \ 58 255) 59 60 #define GPR_ICMP(a, b) ((a) < (b) ? -1 : ((a) > (b) ? 1 : 0)) 61 62 #define GPR_HASH_POINTER(x, range) \ 63 ((((size_t)x) >> 4) ^ (((size_t)x) >> 9) ^ (((size_t)x) >> 14)) % (range) 64 65 #endif /* GRPC_CORE_LIB_GPR_USEFUL_H */ 66