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 /* 44 * Override sections flags/type generated by the C compiler to make sure they 45 * are: "a",%progbits (thus creating an allocatable, non-writeable, non- 46 * executable data section). 47 * The trailing '//' comments out the flags generated by the compiler. 48 * This avoids a harmless warning with GCC 8.x. 49 */ 50 #define __SECTION_FLAGS_RODATA ",\"a\",%progbits //" 51 #define __rodata __section(".rodata" __SECTION_FLAGS_RODATA) 52 #define __rodata_unpaged __section(".rodata.__unpaged" __SECTION_FLAGS_RODATA) 53 #ifdef CFG_VIRTUALIZATION 54 #define __nex_bss __section(".nex_bss") 55 #define __nex_data __section(".nex_data") 56 #else /* CFG_VIRTUALIZATION */ 57 #define __nex_bss __bss 58 #define __nex_data __data 59 #endif /* CFG_VIRTUALIZATION */ 60 #define __noprof __attribute__((no_instrument_function)) 61 62 #define __compiler_bswap64(x) __builtin_bswap64((x)) 63 #define __compiler_bswap32(x) __builtin_bswap32((x)) 64 #define __compiler_bswap16(x) __builtin_bswap16((x)) 65 66 #define __GCC_VERSION (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + \ 67 __GNUC_PATCHLEVEL__) 68 69 #if __GCC_VERSION >= 50100 && !defined(__CHECKER__) 70 #define __HAVE_BUILTIN_OVERFLOW 1 71 #endif 72 73 #ifdef __HAVE_BUILTIN_OVERFLOW 74 #define __compiler_add_overflow(a, b, res) \ 75 __builtin_add_overflow((a), (b), (res)) 76 77 #define __compiler_sub_overflow(a, b, res) \ 78 __builtin_sub_overflow((a), (b), (res)) 79 80 #define __compiler_mul_overflow(a, b, res) \ 81 __builtin_mul_overflow((a), (b), (res)) 82 #else /*!__HAVE_BUILTIN_OVERFLOW*/ 83 84 /* 85 * Copied/inspired from https://www.fefe.de/intof.html 86 */ 87 88 #define __INTOF_ASSIGN(dest, src) (__extension__({ \ 89 typeof(src) __intof_x = (src); \ 90 typeof(dest) __intof_y = __intof_x; \ 91 (((uintmax_t)__intof_x == (uintmax_t)__intof_y) && \ 92 ((__intof_x < 1) == (__intof_y < 1)) ? \ 93 (void)((dest) = __intof_y) , 0 : 1); \ 94 })) 95 96 #define __INTOF_ADD(c, a, b) (__extension__({ \ 97 typeof(a) __intofa_a = (a); \ 98 typeof(b) __intofa_b = (b); \ 99 intmax_t __intofa_a_signed = __intofa_a; \ 100 uintmax_t __intofa_a_unsigned = __intofa_a; \ 101 intmax_t __intofa_b_signed = __intofa_b; \ 102 uintmax_t __intofa_b_unsigned = __intofa_b; \ 103 \ 104 __intofa_b < 1 ? \ 105 __intofa_a < 1 ? \ 106 ((INTMAX_MIN - __intofa_b_signed <= \ 107 __intofa_a_signed)) ? \ 108 __INTOF_ASSIGN((c), __intofa_a_signed + \ 109 __intofa_b_signed) : 1 \ 110 : \ 111 ((__intofa_a_unsigned >= (uintmax_t)-__intofa_b) ? \ 112 __INTOF_ASSIGN((c), __intofa_a_unsigned + \ 113 __intofa_b_signed) \ 114 : \ 115 __INTOF_ASSIGN((c), \ 116 (intmax_t)(__intofa_a_unsigned + \ 117 __intofa_b_signed))) \ 118 : \ 119 __intofa_a < 1 ? \ 120 ((__intofa_b_unsigned >= (uintmax_t)-__intofa_a) ? \ 121 __INTOF_ASSIGN((c), __intofa_a_signed + \ 122 __intofa_b_unsigned) \ 123 : \ 124 __INTOF_ASSIGN((c), \ 125 (intmax_t)(__intofa_a_signed + \ 126 __intofa_b_unsigned))) \ 127 : \ 128 ((UINTMAX_MAX - __intofa_b_unsigned >= \ 129 __intofa_a_unsigned) ? \ 130 __INTOF_ASSIGN((c), __intofa_a_unsigned + \ 131 __intofa_b_unsigned) : 1); \ 132 })) 133 134 #define __INTOF_SUB(c, a, b) (__extension__({ \ 135 typeof(a) __intofs_a = a; \ 136 typeof(b) __intofs_b = b; \ 137 intmax_t __intofs_a_signed = __intofs_a; \ 138 uintmax_t __intofs_a_unsigned = __intofs_a; \ 139 intmax_t __intofs_b_signed = __intofs_b; \ 140 uintmax_t __intofs_b_unsigned = __intofs_b; \ 141 \ 142 __intofs_b < 1 ? \ 143 __intofs_a < 1 ? \ 144 ((INTMAX_MAX + __intofs_b >= __intofs_a) ? \ 145 __INTOF_ASSIGN((c), __intofs_a_signed - \ 146 __intofs_b_signed) : 1) \ 147 : \ 148 (((uintmax_t)(UINTMAX_MAX + __intofs_b_signed) >= \ 149 __intofs_a_unsigned) ? \ 150 __INTOF_ASSIGN((c), __intofs_a - \ 151 __intofs_b) : 1) \ 152 : \ 153 __intofs_a < 1 ? \ 154 (((INTMAX_MIN + __intofs_b <= __intofs_a)) ? \ 155 __INTOF_ASSIGN((c), \ 156 (intmax_t)(__intofs_a_signed - \ 157 __intofs_b_unsigned)) : 1) \ 158 : \ 159 ((__intofs_b_unsigned <= __intofs_a_unsigned) ? \ 160 __INTOF_ASSIGN((c), __intofs_a_unsigned - \ 161 __intofs_b_unsigned) \ 162 : \ 163 __INTOF_ASSIGN((c), \ 164 (intmax_t)(__intofs_a_unsigned - \ 165 __intofs_b_unsigned))); \ 166 })) 167 168 /* 169 * Dealing with detecting overflow in multiplication of integers. 170 * 171 * First step is to remove two corner cases with the minum signed integer 172 * which can't be represented as a positive integer + sign. 173 * Multiply with 0 or 1 can't overflow, no checking needed of the operation, 174 * only if it can be assigned to the result. 175 * 176 * After the corner cases are eliminated we convert the two factors to 177 * positive unsigned values, keeping track of the original in another 178 * variable which is used at the end to determine the sign of the product. 179 * 180 * The two terms (a and b) are divided into upper and lower half (x1 upper 181 * and x0 lower), so the product is: 182 * ((a1 << hshift) + a0) * ((b1 << hshift) + b0) 183 * which also is: 184 * ((a1 * b1) << (hshift * 2)) + (T1) 185 * ((a1 * b0 + a0 * b1) << hshift) + (T2) 186 * (a0 * b0) (T3) 187 * 188 * From this we can tell and (a1 * b1) has to be 0 or we'll overflow, that 189 * is, at least one of a1 or b1 has to be 0. Once this has been checked the 190 * addition: ((a1 * b0) << hshift) + ((a0 * b1) << hshift) 191 * isn't an addition as one of the terms will be 0. 192 * 193 * Since each factor in: (a0 * b0) 194 * only uses half the capicity of the underlaying type it can't overflow 195 * 196 * The addition of T2 and T3 can overflow so we use __INTOF_ADD() to 197 * perform that addition. If the addition succeeds without overflow the 198 * result is assigned the required sign and checked for overflow again. 199 */ 200 201 #define __intof_mul_negate ((__intof_oa < 1) != (__intof_ob < 1)) 202 #define __intof_mul_hshift (sizeof(uintmax_t) * 8 / 2) 203 #define __intof_mul_hmask (UINTMAX_MAX >> __intof_mul_hshift) 204 #define __intof_mul_a0 ((uintmax_t)(__intof_a) >> __intof_mul_hshift) 205 #define __intof_mul_b0 ((uintmax_t)(__intof_b) >> __intof_mul_hshift) 206 #define __intof_mul_a1 ((uintmax_t)(__intof_a) & __intof_mul_hmask) 207 #define __intof_mul_b1 ((uintmax_t)(__intof_b) & __intof_mul_hmask) 208 #define __intof_mul_t (__intof_mul_a1 * __intof_mul_b0 + \ 209 __intof_mul_a0 * __intof_mul_b1) 210 211 #define __INTOF_MUL(c, a, b) (__extension__({ \ 212 typeof(a) __intof_oa = (a); \ 213 typeof(a) __intof_a = __intof_oa < 1 ? -__intof_oa : __intof_oa; \ 214 typeof(b) __intof_ob = (b); \ 215 typeof(b) __intof_b = __intof_ob < 1 ? -__intof_ob : __intof_ob; \ 216 typeof(c) __intof_c; \ 217 \ 218 __intof_oa == 0 || __intof_ob == 0 || \ 219 __intof_oa == 1 || __intof_ob == 1 ? \ 220 __INTOF_ASSIGN((c), __intof_oa * __intof_ob) : \ 221 (__intof_mul_a0 && __intof_mul_b0) || \ 222 __intof_mul_t > __intof_mul_hmask ? 1 : \ 223 __INTOF_ADD((__intof_c), __intof_mul_t << __intof_mul_hshift, \ 224 __intof_mul_a1 * __intof_mul_b1) ? 1 : \ 225 __intof_mul_negate ? __INTOF_ASSIGN((c), -__intof_c) : \ 226 __INTOF_ASSIGN((c), __intof_c); \ 227 })) 228 229 #define __compiler_add_overflow(a, b, res) __INTOF_ADD(*(res), (a), (b)) 230 #define __compiler_sub_overflow(a, b, res) __INTOF_SUB(*(res), (a), (b)) 231 #define __compiler_mul_overflow(a, b, res) __INTOF_MUL(*(res), (a), (b)) 232 233 #endif /*!__HAVE_BUILTIN_OVERFLOW*/ 234 235 #define __compiler_compare_and_swap(p, oval, nval) \ 236 __atomic_compare_exchange_n((p), (oval), (nval), true, \ 237 __ATOMIC_ACQUIRE, __ATOMIC_RELAXED) \ 238 239 #define __compiler_atomic_load(p) __atomic_load_n((p), __ATOMIC_RELAXED) 240 #define __compiler_atomic_store(p, val) \ 241 __atomic_store_n((p), (val), __ATOMIC_RELAXED) 242 243 #endif /*COMPILER_H*/ 244