1 /* SPDX-License-Identifier: BSD-2-Clause */ 2 /* 3 * Copyright (c) 2014, STMicroelectronics International N.V. 4 */ 5 6 #ifndef COMPILER_H 7 #define COMPILER_H 8 9 /* 10 * Macros that should be used instead of using __attribute__ directly to 11 * ease portability and make the code easier to read. 12 * 13 * Some of the defines below is known to sometimes cause conflicts when 14 * this file is included from xtest in normal world. It is assumed that 15 * the conflicting defines has the same meaning in that environment. 16 * Surrounding the troublesome defines with #ifndef should be enough. 17 */ 18 #define __deprecated __attribute__((deprecated)) 19 #ifndef __packed 20 #define __packed __attribute__((packed)) 21 #endif 22 #define __weak __attribute__((weak)) 23 #ifndef __noreturn 24 #define __noreturn __attribute__((__noreturn__)) 25 #endif 26 #define __pure __attribute__((pure)) 27 #define __aligned(x) __attribute__((aligned(x))) 28 #define __printf(a, b) __attribute__((format(printf, a, b))) 29 #define __noinline __attribute__((noinline)) 30 #define __attr_const __attribute__((__const__)) 31 #ifndef __unused 32 #define __unused __attribute__((unused)) 33 #endif 34 #define __maybe_unused __attribute__((unused)) 35 #ifndef __used 36 #define __used __attribute__((__used__)) 37 #endif 38 #define __must_check __attribute__((warn_unused_result)) 39 #define __cold __attribute__((__cold__)) 40 #define __section(x) __attribute__((section(x))) 41 #define __data __section(".data") 42 #define __bss __section(".bss") 43 #ifdef __clang__ 44 #define __SECTION_FLAGS_RODATA 45 #else 46 /* 47 * Override sections flags/type generated by the C compiler to make sure they 48 * are: "a",%progbits (thus creating an allocatable, non-writeable, non- 49 * executable data section). 50 * The trailing '//' comments out the flags generated by the compiler. 51 * This avoids a harmless warning with GCC. 52 */ 53 #define __SECTION_FLAGS_RODATA ",\"a\",%progbits //" 54 #endif 55 #define __rodata __section(".rodata" __SECTION_FLAGS_RODATA) 56 #define __rodata_unpaged __section(".rodata.__unpaged" __SECTION_FLAGS_RODATA) 57 #ifdef CFG_VIRTUALIZATION 58 #define __nex_bss __section(".nex_bss") 59 #define __nex_data __section(".nex_data") 60 #else /* CFG_VIRTUALIZATION */ 61 #define __nex_bss 62 #define __nex_data 63 #endif /* CFG_VIRTUALIZATION */ 64 #define __noprof __attribute__((no_instrument_function)) 65 #define __nostackcheck __attribute__((no_instrument_function)) 66 67 #define __compiler_bswap64(x) __builtin_bswap64((x)) 68 #define __compiler_bswap32(x) __builtin_bswap32((x)) 69 #define __compiler_bswap16(x) __builtin_bswap16((x)) 70 71 #define __GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + \ 72 __GNUC_PATCHLEVEL__) 73 74 #if __GCC_VERSION >= 50100 && !defined(__CHECKER__) 75 #define __HAVE_BUILTIN_OVERFLOW 1 76 #endif 77 78 #ifdef __HAVE_BUILTIN_OVERFLOW 79 #define __compiler_add_overflow(a, b, res) \ 80 __builtin_add_overflow((a), (b), (res)) 81 82 #define __compiler_sub_overflow(a, b, res) \ 83 __builtin_sub_overflow((a), (b), (res)) 84 85 #define __compiler_mul_overflow(a, b, res) \ 86 __builtin_mul_overflow((a), (b), (res)) 87 #else /*!__HAVE_BUILTIN_OVERFLOW*/ 88 89 /* 90 * Copied/inspired from https://www.fefe.de/intof.html 91 */ 92 93 #define __INTOF_ASSIGN(dest, src) (__extension__({ \ 94 typeof(src) __intof_x = (src); \ 95 typeof(dest) __intof_y = __intof_x; \ 96 (((uintmax_t)__intof_x == (uintmax_t)__intof_y) && \ 97 ((__intof_x < 1) == (__intof_y < 1)) ? \ 98 (void)((dest) = __intof_y) , 0 : 1); \ 99 })) 100 101 #define __INTOF_ADD(c, a, b) (__extension__({ \ 102 typeof(a) __intofa_a = (a); \ 103 typeof(b) __intofa_b = (b); \ 104 intmax_t __intofa_a_signed = __intofa_a; \ 105 uintmax_t __intofa_a_unsigned = __intofa_a; \ 106 intmax_t __intofa_b_signed = __intofa_b; \ 107 uintmax_t __intofa_b_unsigned = __intofa_b; \ 108 \ 109 __intofa_b < 1 ? \ 110 __intofa_a < 1 ? \ 111 ((INTMAX_MIN - __intofa_b_signed <= \ 112 __intofa_a_signed)) ? \ 113 __INTOF_ASSIGN((c), __intofa_a_signed + \ 114 __intofa_b_signed) : 1 \ 115 : \ 116 ((__intofa_a_unsigned >= (uintmax_t)-__intofa_b) ? \ 117 __INTOF_ASSIGN((c), __intofa_a_unsigned + \ 118 __intofa_b_signed) \ 119 : \ 120 __INTOF_ASSIGN((c), \ 121 (intmax_t)(__intofa_a_unsigned + \ 122 __intofa_b_signed))) \ 123 : \ 124 __intofa_a < 1 ? \ 125 ((__intofa_b_unsigned >= (uintmax_t)-__intofa_a) ? \ 126 __INTOF_ASSIGN((c), __intofa_a_signed + \ 127 __intofa_b_unsigned) \ 128 : \ 129 __INTOF_ASSIGN((c), \ 130 (intmax_t)(__intofa_a_signed + \ 131 __intofa_b_unsigned))) \ 132 : \ 133 ((UINTMAX_MAX - __intofa_b_unsigned >= \ 134 __intofa_a_unsigned) ? \ 135 __INTOF_ASSIGN((c), __intofa_a_unsigned + \ 136 __intofa_b_unsigned) : 1); \ 137 })) 138 139 #define __INTOF_SUB(c, a, b) (__extension__({ \ 140 typeof(a) __intofs_a = a; \ 141 typeof(b) __intofs_b = b; \ 142 intmax_t __intofs_a_signed = __intofs_a; \ 143 uintmax_t __intofs_a_unsigned = __intofs_a; \ 144 intmax_t __intofs_b_signed = __intofs_b; \ 145 uintmax_t __intofs_b_unsigned = __intofs_b; \ 146 \ 147 __intofs_b < 1 ? \ 148 __intofs_a < 1 ? \ 149 ((INTMAX_MAX + __intofs_b_signed >= \ 150 __intofs_a_signed) ? \ 151 __INTOF_ASSIGN((c), __intofs_a_signed - \ 152 __intofs_b_signed) : 1) \ 153 : \ 154 (((uintmax_t)(UINTMAX_MAX + __intofs_b_signed) >= \ 155 __intofs_a_unsigned) ? \ 156 __INTOF_ASSIGN((c), __intofs_a - \ 157 __intofs_b) : 1) \ 158 : \ 159 __intofs_a < 1 ? \ 160 (((intmax_t)(INTMAX_MIN + __intofs_b) <= \ 161 __intofs_a_signed) ? \ 162 __INTOF_ASSIGN((c), \ 163 (intmax_t)(__intofs_a_signed - \ 164 __intofs_b_unsigned)) : 1) \ 165 : \ 166 ((__intofs_b_unsigned <= __intofs_a_unsigned) ? \ 167 __INTOF_ASSIGN((c), __intofs_a_unsigned - \ 168 __intofs_b_unsigned) \ 169 : \ 170 __INTOF_ASSIGN((c), \ 171 (intmax_t)(__intofs_a_unsigned - \ 172 __intofs_b_unsigned))); \ 173 })) 174 175 /* 176 * Dealing with detecting overflow in multiplication of integers. 177 * 178 * First step is to remove two corner cases with the minum signed integer 179 * which can't be represented as a positive integer + sign. 180 * Multiply with 0 or 1 can't overflow, no checking needed of the operation, 181 * only if it can be assigned to the result. 182 * 183 * After the corner cases are eliminated we convert the two factors to 184 * positive unsigned values, keeping track of the original in another 185 * variable which is used at the end to determine the sign of the product. 186 * 187 * The two terms (a and b) are divided into upper and lower half (x1 upper 188 * and x0 lower), so the product is: 189 * ((a1 << hshift) + a0) * ((b1 << hshift) + b0) 190 * which also is: 191 * ((a1 * b1) << (hshift * 2)) + (T1) 192 * ((a1 * b0 + a0 * b1) << hshift) + (T2) 193 * (a0 * b0) (T3) 194 * 195 * From this we can tell and (a1 * b1) has to be 0 or we'll overflow, that 196 * is, at least one of a1 or b1 has to be 0. Once this has been checked the 197 * addition: ((a1 * b0) << hshift) + ((a0 * b1) << hshift) 198 * isn't an addition as one of the terms will be 0. 199 * 200 * Since each factor in: (a0 * b0) 201 * only uses half the capicity of the underlaying type it can't overflow 202 * 203 * The addition of T2 and T3 can overflow so we use __INTOF_ADD() to 204 * perform that addition. If the addition succeeds without overflow the 205 * result is assigned the required sign and checked for overflow again. 206 */ 207 208 #define __intof_mul_negate ((__intof_oa < 1) != (__intof_ob < 1)) 209 #define __intof_mul_hshift (sizeof(uintmax_t) * 8 / 2) 210 #define __intof_mul_hmask (UINTMAX_MAX >> __intof_mul_hshift) 211 #define __intof_mul_a0 ((uintmax_t)(__intof_a) >> __intof_mul_hshift) 212 #define __intof_mul_b0 ((uintmax_t)(__intof_b) >> __intof_mul_hshift) 213 #define __intof_mul_a1 ((uintmax_t)(__intof_a) & __intof_mul_hmask) 214 #define __intof_mul_b1 ((uintmax_t)(__intof_b) & __intof_mul_hmask) 215 #define __intof_mul_t (__intof_mul_a1 * __intof_mul_b0 + \ 216 __intof_mul_a0 * __intof_mul_b1) 217 218 #define __INTOF_MUL(c, a, b) (__extension__({ \ 219 typeof(a) __intof_oa = (a); \ 220 typeof(a) __intof_a = __intof_oa < 1 ? -__intof_oa : __intof_oa; \ 221 typeof(b) __intof_ob = (b); \ 222 typeof(b) __intof_b = __intof_ob < 1 ? -__intof_ob : __intof_ob; \ 223 typeof(c) __intof_c; \ 224 \ 225 __intof_oa == 0 || __intof_ob == 0 || \ 226 __intof_oa == 1 || __intof_ob == 1 ? \ 227 __INTOF_ASSIGN((c), __intof_oa * __intof_ob) : \ 228 (__intof_mul_a0 && __intof_mul_b0) || \ 229 __intof_mul_t > __intof_mul_hmask ? 1 : \ 230 __INTOF_ADD((__intof_c), __intof_mul_t << __intof_mul_hshift, \ 231 __intof_mul_a1 * __intof_mul_b1) ? 1 : \ 232 __intof_mul_negate ? __INTOF_ASSIGN((c), -__intof_c) : \ 233 __INTOF_ASSIGN((c), __intof_c); \ 234 })) 235 236 #define __compiler_add_overflow(a, b, res) __INTOF_ADD(*(res), (a), (b)) 237 #define __compiler_sub_overflow(a, b, res) __INTOF_SUB(*(res), (a), (b)) 238 #define __compiler_mul_overflow(a, b, res) __INTOF_MUL(*(res), (a), (b)) 239 240 #endif /*!__HAVE_BUILTIN_OVERFLOW*/ 241 242 #define __compiler_compare_and_swap(p, oval, nval) \ 243 __atomic_compare_exchange_n((p), (oval), (nval), true, \ 244 __ATOMIC_ACQUIRE, __ATOMIC_RELAXED) \ 245 246 #define __compiler_atomic_load(p) __atomic_load_n((p), __ATOMIC_RELAXED) 247 #define __compiler_atomic_store(p, val) \ 248 __atomic_store_n((p), (val), __ATOMIC_RELAXED) 249 250 #endif /*COMPILER_H*/ 251