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https://github.com/openvswitch/ovs
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0175bdd46c
Some versions of sparse do not understand __builtin_saddll_overflow() and related GCC builtins for calculations with overflow detection. This patch avoids using them when sparse is in use. Reported-by: Justin Pettit <jpettit@ovn.org> Tested-by: Justin Pettit <jpettit@ovn.org> Acked-by: Justin Pettit <jpettit@ovn.org> Signed-off-by: Ben Pfaff <blp@ovn.org>
110 lines
3.2 KiB
C
110 lines
3.2 KiB
C
/*
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* Copyright (c) 2008, 2012, 2019 Nicira, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef SAT_MATH_H
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#define SAT_MATH_H 1
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#include <limits.h>
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#include "openvswitch/util.h"
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#ifndef __has_builtin
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#define __has_builtin(x) 0
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#endif
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/* Returns x + y, clamping out-of-range results into the range of the return
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* type. */
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static inline unsigned int
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sat_add(unsigned int x, unsigned int y)
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{
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return x + y >= x ? x + y : UINT_MAX;
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}
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static inline long long int
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llsat_add__(long long int x, long long int y)
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{
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return (x >= 0 && y >= 0 && x > LLONG_MAX - y ? LLONG_MAX
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: x < 0 && y < 0 && x < LLONG_MIN - y ? LLONG_MIN
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: x + y);
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}
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static inline long long int
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llsat_add(long long int x, long long int y)
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{
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#if (__GNUC__ >= 5 || __has_builtin(__builtin_saddll_overflow)) && !__CHECKER__
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long long int sum;
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return (!__builtin_saddll_overflow(x, y, &sum) ? sum
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: x > 0 ? LLONG_MAX : LLONG_MIN);
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#else
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return llsat_add__(x, y);
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#endif
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}
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/* Returns x - y, clamping out-of-range results into the range of the return
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* type. */
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static inline unsigned int
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sat_sub(unsigned int x, unsigned int y)
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{
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return x >= y ? x - y : 0;
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}
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static inline long long int
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llsat_sub__(long long int x, long long int y)
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{
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return (x >= 0 && y < 0 && x > LLONG_MAX + y ? LLONG_MAX
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: x < 0 && y >= 0 && x < LLONG_MIN + y ? LLONG_MIN
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: x - y);
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}
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static inline long long int
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llsat_sub(long long int x, long long int y)
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{
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#if (__GNUC__ >= 5 || __has_builtin(__builtin_ssubll_overflow)) && !__CHECKER__
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long long int difference;
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return (!__builtin_ssubll_overflow(x, y, &difference) ? difference
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: x >= 0 ? LLONG_MAX : LLONG_MIN);
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#else
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return llsat_sub__(x, y);
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#endif
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}
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/* Returns x * y, clamping out-of-range results into the range of the return
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* type. */
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static inline unsigned int
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sat_mul(unsigned int x, unsigned int y)
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{
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return OVS_SAT_MUL(x, y);
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}
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static inline long long int
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llsat_mul__(long long int x, long long int y)
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{
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return ( x > 0 && y > 0 && x > LLONG_MAX / y ? LLONG_MAX
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: x < 0 && y > 0 && x < LLONG_MIN / y ? LLONG_MIN
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: x > 0 && y < 0 && y < LLONG_MIN / x ? LLONG_MIN
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/* Special case because -LLONG_MIN / -1 overflows: */
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: x == LLONG_MIN && y == -1 ? LLONG_MAX
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: x < 0 && y < 0 && x < LLONG_MAX / y ? LLONG_MAX
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: x * y);
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}
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static inline long long int
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llsat_mul(long long int x, long long int y)
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{
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#if (__GNUC__ >= 5 || __has_builtin(__builtin_smulll_overflow)) && !__CHECKER__
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long long int product;
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return (!__builtin_smulll_overflow(x, y, &product) ? product
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: (x > 0) == (y > 0) ? LLONG_MAX : LLONG_MIN);
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#else
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return llsat_mul__(x, y);
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#endif
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}
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#endif /* sat-math.h */
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