| /* |
| * |
| * Copyright 2015 gRPC authors. |
| * |
| * 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 GRPC_CORE_LIB_GPR_USEFUL_H |
| #define GRPC_CORE_LIB_GPR_USEFUL_H |
| |
| /** useful macros that don't belong anywhere else */ |
| |
| #define GPR_MIN(a, b) ((a) < (b) ? (a) : (b)) |
| #define GPR_MAX(a, b) ((a) > (b) ? (a) : (b)) |
| #define GPR_CLAMP(a, min, max) ((a) < (min) ? (min) : (a) > (max) ? (max) : (a)) |
| /** rotl, rotr assume x is unsigned */ |
| #define GPR_ROTL(x, n) (((x) << (n)) | ((x) >> (sizeof(x) * 8 - (n)))) |
| #define GPR_ROTR(x, n) (((x) >> (n)) | ((x) << (sizeof(x) * 8 - (n)))) |
| |
| #define GPR_ARRAY_SIZE(array) (sizeof(array) / sizeof(*(array))) |
| |
| #define GPR_SWAP(type, a, b) \ |
| do { \ |
| type x = a; \ |
| a = b; \ |
| b = x; \ |
| } while (0) |
| |
| /** Set the \a n-th bit of \a i (a mutable pointer). */ |
| #define GPR_BITSET(i, n) ((*(i)) |= (1u << (n))) |
| |
| /** Clear the \a n-th bit of \a i (a mutable pointer). */ |
| #define GPR_BITCLEAR(i, n) ((*(i)) &= ~(1u << (n))) |
| |
| /** Get the \a n-th bit of \a i */ |
| #define GPR_BITGET(i, n) (((i) & (1u << (n))) != 0) |
| |
| #define GPR_INTERNAL_HEXDIGIT_BITCOUNT(x) \ |
| ((x) - (((x) >> 1) & 0x77777777) - (((x) >> 2) & 0x33333333) - \ |
| (((x) >> 3) & 0x11111111)) |
| |
| /** Returns number of bits set in bitset \a i */ |
| #define GPR_BITCOUNT(i) \ |
| (((GPR_INTERNAL_HEXDIGIT_BITCOUNT(i) + \ |
| (GPR_INTERNAL_HEXDIGIT_BITCOUNT(i) >> 4)) & \ |
| 0x0f0f0f0f) % \ |
| 255) |
| |
| #define GPR_ICMP(a, b) ((a) < (b) ? -1 : ((a) > (b) ? 1 : 0)) |
| |
| #define GPR_HASH_POINTER(x, range) \ |
| ((((size_t)x) >> 4) ^ (((size_t)x) >> 9) ^ (((size_t)x) >> 14)) % (range) |
| |
| #endif /* GRPC_CORE_LIB_GPR_USEFUL_H */ |