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_dummy __section(".rodata.dummy" __SECTION_FLAGS_RODATA) 57 #define __rodata_unpaged(x) \ 58 __section(".rodata.__unpaged." x __SECTION_FLAGS_RODATA) 59 #ifdef CFG_VIRTUALIZATION 60 #define __nex_bss __section(".nex_bss") 61 #define __nex_data __section(".nex_data") 62 #else /* CFG_VIRTUALIZATION */ 63 #define __nex_bss 64 #define __nex_data 65 #endif /* CFG_VIRTUALIZATION */ 66 #define __noprof __attribute__((no_instrument_function)) 67 #define __nostackcheck __attribute__((no_instrument_function)) 68 69 #define __compiler_bswap64(x) __builtin_bswap64((x)) 70 #define __compiler_bswap32(x) __builtin_bswap32((x)) 71 #define __compiler_bswap16(x) __builtin_bswap16((x)) 72 73 #define __GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + \ 74 __GNUC_PATCHLEVEL__) 75 76 #if __GCC_VERSION >= 50100 && !defined(__CHECKER__) 77 #define __HAVE_BUILTIN_OVERFLOW 1 78 #endif 79 80 #ifdef __HAVE_BUILTIN_OVERFLOW 81 #define __compiler_add_overflow(a, b, res) \ 82 __builtin_add_overflow((a), (b), (res)) 83 84 #define __compiler_sub_overflow(a, b, res) \ 85 __builtin_sub_overflow((a), (b), (res)) 86 87 #define __compiler_mul_overflow(a, b, res) \ 88 __builtin_mul_overflow((a), (b), (res)) 89 #else /*!__HAVE_BUILTIN_OVERFLOW*/ 90 91 /* 92 * Copied/inspired from https://www.fefe.de/intof.html 93 */ 94 95 #define __INTOF_ASSIGN(dest, src) (__extension__({ \ 96 typeof(src) __intof_x = (src); \ 97 typeof(dest) __intof_y = __intof_x; \ 98 (((uintmax_t)__intof_x == (uintmax_t)__intof_y) && \ 99 ((__intof_x < 1) == (__intof_y < 1)) ? \ 100 (void)((dest) = __intof_y) , 0 : 1); \ 101 })) 102 103 #define __INTOF_ADD(c, a, b) (__extension__({ \ 104 typeof(a) __intofa_a = (a); \ 105 typeof(b) __intofa_b = (b); \ 106 intmax_t __intofa_a_signed = __intofa_a; \ 107 uintmax_t __intofa_a_unsigned = __intofa_a; \ 108 intmax_t __intofa_b_signed = __intofa_b; \ 109 uintmax_t __intofa_b_unsigned = __intofa_b; \ 110 \ 111 __intofa_b < 1 ? \ 112 __intofa_a < 1 ? \ 113 ((INTMAX_MIN - __intofa_b_signed <= \ 114 __intofa_a_signed)) ? \ 115 __INTOF_ASSIGN((c), __intofa_a_signed + \ 116 __intofa_b_signed) : 1 \ 117 : \ 118 ((__intofa_a_unsigned >= (uintmax_t)-__intofa_b) ? \ 119 __INTOF_ASSIGN((c), __intofa_a_unsigned + \ 120 __intofa_b_signed) \ 121 : \ 122 __INTOF_ASSIGN((c), \ 123 (intmax_t)(__intofa_a_unsigned + \ 124 __intofa_b_signed))) \ 125 : \ 126 __intofa_a < 1 ? \ 127 ((__intofa_b_unsigned >= (uintmax_t)-__intofa_a) ? \ 128 __INTOF_ASSIGN((c), __intofa_a_signed + \ 129 __intofa_b_unsigned) \ 130 : \ 131 __INTOF_ASSIGN((c), \ 132 (intmax_t)(__intofa_a_signed + \ 133 __intofa_b_unsigned))) \ 134 : \ 135 ((UINTMAX_MAX - __intofa_b_unsigned >= \ 136 __intofa_a_unsigned) ? \ 137 __INTOF_ASSIGN((c), __intofa_a_unsigned + \ 138 __intofa_b_unsigned) : 1); \ 139 })) 140 141 #define __INTOF_SUB(c, a, b) (__extension__({ \ 142 typeof(a) __intofs_a = a; \ 143 typeof(b) __intofs_b = b; \ 144 intmax_t __intofs_a_signed = __intofs_a; \ 145 uintmax_t __intofs_a_unsigned = __intofs_a; \ 146 intmax_t __intofs_b_signed = __intofs_b; \ 147 uintmax_t __intofs_b_unsigned = __intofs_b; \ 148 \ 149 __intofs_b < 1 ? \ 150 __intofs_a < 1 ? \ 151 ((INTMAX_MAX + __intofs_b_signed >= \ 152 __intofs_a_signed) ? \ 153 __INTOF_ASSIGN((c), __intofs_a_signed - \ 154 __intofs_b_signed) : 1) \ 155 : \ 156 (((uintmax_t)(UINTMAX_MAX + __intofs_b_signed) >= \ 157 __intofs_a_unsigned) ? \ 158 __INTOF_ASSIGN((c), __intofs_a - \ 159 __intofs_b) : 1) \ 160 : \ 161 __intofs_a < 1 ? \ 162 (((intmax_t)(INTMAX_MIN + __intofs_b) <= \ 163 __intofs_a_signed) ? \ 164 __INTOF_ASSIGN((c), \ 165 (intmax_t)(__intofs_a_signed - \ 166 __intofs_b_unsigned)) : 1) \ 167 : \ 168 ((__intofs_b_unsigned <= __intofs_a_unsigned) ? \ 169 __INTOF_ASSIGN((c), __intofs_a_unsigned - \ 170 __intofs_b_unsigned) \ 171 : \ 172 __INTOF_ASSIGN((c), \ 173 (intmax_t)(__intofs_a_unsigned - \ 174 __intofs_b_unsigned))); \ 175 })) 176 177 /* 178 * Dealing with detecting overflow in multiplication of integers. 179 * 180 * First step is to remove two corner cases with the minum signed integer 181 * which can't be represented as a positive integer + sign. 182 * Multiply with 0 or 1 can't overflow, no checking needed of the operation, 183 * only if it can be assigned to the result. 184 * 185 * After the corner cases are eliminated we convert the two factors to 186 * positive unsigned values, keeping track of the original in another 187 * variable which is used at the end to determine the sign of the product. 188 * 189 * The two terms (a and b) are divided into upper and lower half (x1 upper 190 * and x0 lower), so the product is: 191 * ((a1 << hshift) + a0) * ((b1 << hshift) + b0) 192 * which also is: 193 * ((a1 * b1) << (hshift * 2)) + (T1) 194 * ((a1 * b0 + a0 * b1) << hshift) + (T2) 195 * (a0 * b0) (T3) 196 * 197 * From this we can tell and (a1 * b1) has to be 0 or we'll overflow, that 198 * is, at least one of a1 or b1 has to be 0. Once this has been checked the 199 * addition: ((a1 * b0) << hshift) + ((a0 * b1) << hshift) 200 * isn't an addition as one of the terms will be 0. 201 * 202 * Since each factor in: (a0 * b0) 203 * only uses half the capicity of the underlaying type it can't overflow 204 * 205 * The addition of T2 and T3 can overflow so we use __INTOF_ADD() to 206 * perform that addition. If the addition succeeds without overflow the 207 * result is assigned the required sign and checked for overflow again. 208 */ 209 210 #define __intof_mul_negate ((__intof_oa < 1) != (__intof_ob < 1)) 211 #define __intof_mul_hshift (sizeof(uintmax_t) * 8 / 2) 212 #define __intof_mul_hmask (UINTMAX_MAX >> __intof_mul_hshift) 213 #define __intof_mul_a0 ((uintmax_t)(__intof_a) >> __intof_mul_hshift) 214 #define __intof_mul_b0 ((uintmax_t)(__intof_b) >> __intof_mul_hshift) 215 #define __intof_mul_a1 ((uintmax_t)(__intof_a) & __intof_mul_hmask) 216 #define __intof_mul_b1 ((uintmax_t)(__intof_b) & __intof_mul_hmask) 217 #define __intof_mul_t (__intof_mul_a1 * __intof_mul_b0 + \ 218 __intof_mul_a0 * __intof_mul_b1) 219 220 #define __INTOF_MUL(c, a, b) (__extension__({ \ 221 typeof(a) __intof_oa = (a); \ 222 typeof(a) __intof_a = __intof_oa < 1 ? -__intof_oa : __intof_oa; \ 223 typeof(b) __intof_ob = (b); \ 224 typeof(b) __intof_b = __intof_ob < 1 ? -__intof_ob : __intof_ob; \ 225 typeof(c) __intof_c; \ 226 \ 227 __intof_oa == 0 || __intof_ob == 0 || \ 228 __intof_oa == 1 || __intof_ob == 1 ? \ 229 __INTOF_ASSIGN((c), __intof_oa * __intof_ob) : \ 230 (__intof_mul_a0 && __intof_mul_b0) || \ 231 __intof_mul_t > __intof_mul_hmask ? 1 : \ 232 __INTOF_ADD((__intof_c), __intof_mul_t << __intof_mul_hshift, \ 233 __intof_mul_a1 * __intof_mul_b1) ? 1 : \ 234 __intof_mul_negate ? __INTOF_ASSIGN((c), -__intof_c) : \ 235 __INTOF_ASSIGN((c), __intof_c); \ 236 })) 237 238 #define __compiler_add_overflow(a, b, res) __INTOF_ADD(*(res), (a), (b)) 239 #define __compiler_sub_overflow(a, b, res) __INTOF_SUB(*(res), (a), (b)) 240 #define __compiler_mul_overflow(a, b, res) __INTOF_MUL(*(res), (a), (b)) 241 242 #endif /*!__HAVE_BUILTIN_OVERFLOW*/ 243 244 #define __compiler_compare_and_swap(p, oval, nval) \ 245 __atomic_compare_exchange_n((p), (oval), (nval), true, \ 246 __ATOMIC_ACQUIRE, __ATOMIC_RELAXED) \ 247 248 #define __compiler_atomic_load(p) __atomic_load_n((p), __ATOMIC_RELAXED) 249 #define __compiler_atomic_store(p, val) \ 250 __atomic_store_n((p), (val), __ATOMIC_RELAXED) 251 252 #define barrier() asm volatile ("" : : : "memory") 253 254 #ifndef __has_attribute 255 #define __has_attribute(x) 0 256 #endif 257 258 #if __has_attribute(__fallthrough__) 259 #define fallthrough __attribute__((__fallthrough__)) 260 #else 261 #define fallthrough do {} while (0) /* fallthrough */ 262 #endif 263 264 #endif /*COMPILER_H*/ 265