1 /* SPDX-License-Identifier: BSD-2-Clause */ 2 /* 3 * Copyright (c) 2014, STMicroelectronics International N.V. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright notice, 10 * this list of conditions and the following disclaimer. 11 * 12 * 2. Redistributions in binary form must reproduce the above copyright notice, 13 * this list of conditions and the following disclaimer in the documentation 14 * and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #ifndef COMPILER_H 30 #define COMPILER_H 31 32 /* 33 * Macros that should be used instead of using __attribute__ directly to 34 * ease portability and make the code easier to read. 35 */ 36 37 #define __deprecated __attribute__((deprecated)) 38 #define __packed __attribute__((packed)) 39 #define __weak __attribute__((weak)) 40 #define __noreturn __attribute__((noreturn)) 41 #define __pure __attribute__((pure)) 42 #define __aligned(x) __attribute__((aligned(x))) 43 #define __printf(a, b) __attribute__((format(printf, a, b))) 44 #define __noinline __attribute__((noinline)) 45 #define __attr_const __attribute__((__const__)) 46 #define __unused __attribute__((unused)) 47 #define __maybe_unused __attribute__((unused)) 48 #define __used __attribute__((__used__)) 49 #define __must_check __attribute__((warn_unused_result)) 50 #define __cold __attribute__((__cold__)) 51 #define __section(x) __attribute__((section(x))) 52 #define __data __section(".data") 53 #define __bss __section(".bss") 54 #define __rodata __section(".rodata") 55 #define __rodata_unpaged __section(".rodata.__unpaged") 56 #define __early_ta __section(".rodata.early_ta") 57 #define __noprof __attribute__((no_instrument_function)) 58 59 #define __compiler_bswap64(x) __builtin_bswap64((x)) 60 #define __compiler_bswap32(x) __builtin_bswap32((x)) 61 #define __compiler_bswap16(x) __builtin_bswap16((x)) 62 63 #define __GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + \ 64 __GNUC_PATCHLEVEL__) 65 66 #if __GCC_VERSION >= 50100 && !defined(__CHECKER__) 67 #define __HAVE_BUILTIN_OVERFLOW 1 68 #endif 69 70 #ifdef __HAVE_BUILTIN_OVERFLOW 71 #define __compiler_add_overflow(a, b, res) \ 72 __builtin_add_overflow((a), (b), (res)) 73 74 #define __compiler_sub_overflow(a, b, res) \ 75 __builtin_sub_overflow((a), (b), (res)) 76 77 #define __compiler_mul_overflow(a, b, res) \ 78 __builtin_mul_overflow((a), (b), (res)) 79 #else /*!__HAVE_BUILTIN_OVERFLOW*/ 80 81 /* 82 * Copied/inspired from https://www.fefe.de/intof.html 83 */ 84 #define __INTOF_HALF_MAX_SIGNED(type) ((type)1 << (sizeof(type)*8-2)) 85 #define __INTOF_MAX_SIGNED(type) (__INTOF_HALF_MAX_SIGNED(type) - 1 + \ 86 __INTOF_HALF_MAX_SIGNED(type)) 87 #define __INTOF_MIN_SIGNED(type) (-1 - __INTOF_MAX_SIGNED(type)) 88 89 #define __INTOF_MIN(type) ((type)-1 < 1?__INTOF_MIN_SIGNED(type):(type)0) 90 #define __INTOF_MAX(type) ((type)~__INTOF_MIN(type)) 91 92 #define __INTOF_ASSIGN(dest, src) (__extension__({ \ 93 typeof(src) __intof_x = (src); \ 94 typeof(dest) __intof_y = __intof_x; \ 95 (((uintmax_t)__intof_x == (uintmax_t)__intof_y) && \ 96 ((__intof_x < 1) == (__intof_y < 1)) ? \ 97 (void)((dest) = __intof_y) , 0 : 1); \ 98 })) 99 100 #define __INTOF_ADD(c, a, b) (__extension__({ \ 101 typeof(a) __intofa_a = (a); \ 102 typeof(b) __intofa_b = (b); \ 103 \ 104 __intofa_b < 1 ? \ 105 ((__INTOF_MIN(typeof(c)) - __intofa_b <= __intofa_a) ? \ 106 __INTOF_ASSIGN((c), __intofa_a + __intofa_b) : 1) : \ 107 ((__INTOF_MAX(typeof(c)) - __intofa_b >= __intofa_a) ? \ 108 __INTOF_ASSIGN((c), __intofa_a + __intofa_b) : 1); \ 109 })) 110 111 #define __INTOF_SUB(c, a, b) (__extension__({ \ 112 typeof(a) __intofs_a = a; \ 113 typeof(b) __intofs_b = b; \ 114 \ 115 __intofs_b < 1 ? \ 116 ((__INTOF_MAX(typeof(c)) + __intofs_b >= __intofs_a) ? \ 117 __INTOF_ASSIGN((c), __intofs_a - __intofs_b) : 1) : \ 118 ((__INTOF_MIN(typeof(c)) + __intofs_b <= __intofs_a) ? \ 119 __INTOF_ASSIGN((c), __intofs_a - __intofs_b) : 1); \ 120 })) 121 122 /* 123 * Dealing with detecting overflow in multiplication of integers. 124 * 125 * First step is to remove two corner cases with the minum signed integer 126 * which can't be represented as a positive integer + sign. 127 * Multiply with 0 or 1 can't overflow, no checking needed of the operation, 128 * only if it can be assigned to the result. 129 * 130 * After the corner cases are eliminated we convert the two factors to 131 * positive unsigned values, keeping track of the original in another 132 * variable which is used at the end to determine the sign of the product. 133 * 134 * The two terms (a and b) are divided into upper and lower half (x1 upper 135 * and x0 lower), so the product is: 136 * ((a1 << hshift) + a0) * ((b1 << hshift) + b0) 137 * which also is: 138 * ((a1 * b1) << (hshift * 2)) + (T1) 139 * ((a1 * b0 + a0 * b1) << hshift) + (T2) 140 * (a0 * b0) (T3) 141 * 142 * From this we can tell and (a1 * b1) has to be 0 or we'll overflow, that 143 * is, at least one of a1 or b1 has to be 0. Once this has been checked the 144 * addition: ((a1 * b0) << hshift) + ((a0 * b1) << hshift) 145 * isn't an addition as one of the terms will be 0. 146 * 147 * Since each factor in: (a0 * b0) 148 * only uses half the capicity of the underlaying type it can't overflow 149 * 150 * The addition of T2 and T3 can overflow so we use __INTOF_ADD() to 151 * perform that addition. If the addition succeeds without overflow the 152 * result is assigned the required sign and checked for overflow again. 153 */ 154 155 #define __intof_mul_negate ((__intof_oa < 1) != (__intof_ob < 1)) 156 #define __intof_mul_hshift (sizeof(uintmax_t) * 8 / 2) 157 #define __intof_mul_hmask (UINTMAX_MAX >> __intof_mul_hshift) 158 #define __intof_mul_a0 ((uintmax_t)(__intof_a) >> __intof_mul_hshift) 159 #define __intof_mul_b0 ((uintmax_t)(__intof_b) >> __intof_mul_hshift) 160 #define __intof_mul_a1 ((uintmax_t)(__intof_a) & __intof_mul_hmask) 161 #define __intof_mul_b1 ((uintmax_t)(__intof_b) & __intof_mul_hmask) 162 #define __intof_mul_t (__intof_mul_a1 * __intof_mul_b0 + \ 163 __intof_mul_a0 * __intof_mul_b1) 164 165 #define __INTOF_MUL(c, a, b) (__extension__({ \ 166 typeof(a) __intof_oa = (a); \ 167 typeof(a) __intof_a = __intof_oa < 1 ? -__intof_oa : __intof_oa; \ 168 typeof(b) __intof_ob = (b); \ 169 typeof(b) __intof_b = __intof_ob < 1 ? -__intof_ob : __intof_ob; \ 170 typeof(c) __intof_c; \ 171 \ 172 __intof_oa == 0 || __intof_ob == 0 || \ 173 __intof_oa == 1 || __intof_ob == 1 ? \ 174 __INTOF_ASSIGN((c), __intof_oa * __intof_ob) : \ 175 (__intof_mul_a0 && __intof_mul_b0) || \ 176 __intof_mul_t > __intof_mul_hmask ? 1 : \ 177 __INTOF_ADD((__intof_c), __intof_mul_t << __intof_mul_hshift, \ 178 __intof_mul_a1 * __intof_mul_b1) ? 1 : \ 179 __intof_mul_negate ? __INTOF_ASSIGN((c), -__intof_c) : \ 180 __INTOF_ASSIGN((c), __intof_c); \ 181 })) 182 183 #define __compiler_add_overflow(a, b, res) __INTOF_ADD(*(res), (a), (b)) 184 #define __compiler_sub_overflow(a, b, res) __INTOF_SUB(*(res), (a), (b)) 185 #define __compiler_mul_overflow(a, b, res) __INTOF_MUL(*(res), (a), (b)) 186 187 #endif /*!__HAVE_BUILTIN_OVERFLOW*/ 188 189 #define __compiler_compare_and_swap(p, oval, nval) \ 190 __atomic_compare_exchange_n((p), (oval), (nval), true, \ 191 __ATOMIC_ACQUIRE, __ATOMIC_RELAXED) \ 192 193 #define __compiler_atomic_load(p) __atomic_load_n((p), __ATOMIC_RELAXED) 194 #define __compiler_atomic_store(p, val) \ 195 __atomic_store_n((p), (val), __ATOMIC_RELAXED) 196 197 #endif /*COMPILER_H*/ 198