macro.h

/***************************************************************************************
* Copyright (c) 2014-2024 Zihao Yu, Nanjing University
*
* NEMU is licensed under Mulan PSL v2.
* You can use this software according to the terms and conditions of the Mulan PSL v2.
* You may obtain a copy of Mulan PSL v2 at:
*          http://license.coscl.org.cn/MulanPSL2
*
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
*
* See the Mulan PSL v2 for more details.
***************************************************************************************/

#ifndef __MACRO_H__
#define __MACRO_H__

#include <string.h>

// macro stringizing
#define str_temp(x) #x
#define str(x) str_temp(x)

// strlen() for string constant
#define STRLEN(CONST_STR) (sizeof(CONST_STR) - 1)

// calculate the length of an array
#define ARRLEN(arr) (int)(sizeof(arr) / sizeof(arr[0]))

// macro concatenation
#define concat_temp(x, y) x ## y
#define concat(x, y) concat_temp(x, y)
#define concat3(x, y, z) concat(concat(x, y), z)
#define concat4(x, y, z, w) concat3(concat(x, y), z, w)
#define concat5(x, y, z, v, w) concat4(concat(x, y), z, v, w)

// macro testing
// See https://stackoverflow.com/questions/26099745/test-if-preprocessor-symbol-is-defined-inside-macro
#define CHOOSE2nd(a, b, ...) b
#define MUX_WITH_COMMA(contain_comma, a, b) CHOOSE2nd(contain_comma a, b)
#define MUX_MACRO_PROPERTY(p, macro, a, b) MUX_WITH_COMMA(concat(p, macro), a, b)
// define placeholders for some property
#define __P_DEF_0  X,
#define __P_DEF_1  X,
#define __P_ONE_1  X,
#define __P_ZERO_0 X,
// define some selection functions based on the properties of BOOLEAN macro
#define MUXDEF(macro, X, Y)  MUX_MACRO_PROPERTY(__P_DEF_, macro, X, Y)
#define MUXNDEF(macro, X, Y) MUX_MACRO_PROPERTY(__P_DEF_, macro, Y, X)
#define MUXONE(macro, X, Y)  MUX_MACRO_PROPERTY(__P_ONE_, macro, X, Y)
#define MUXZERO(macro, X, Y) MUX_MACRO_PROPERTY(__P_ZERO_,macro, X, Y)

// test if a boolean macro is defined
#define ISDEF(macro) MUXDEF(macro, 1, 0)
// test if a boolean macro is undefined
#define ISNDEF(macro) MUXNDEF(macro, 1, 0)
// test if a boolean macro is defined to 1
#define ISONE(macro) MUXONE(macro, 1, 0)
// test if a boolean macro is defined to 0
#define ISZERO(macro) MUXZERO(macro, 1, 0)
// test if a macro of ANY type is defined
// NOTE1: it ONLY works inside a function, since it calls `strcmp()`
// NOTE2: macros defined to themselves (#define A A) will get wrong results
#define isdef(macro) (strcmp("" #macro, "" str(macro)) != 0)

// simplification for conditional compilation
#define __IGNORE(...)
#define __KEEP(...) __VA_ARGS__
// keep the code if a boolean macro is defined
#define IFDEF(macro, ...) MUXDEF(macro, __KEEP, __IGNORE)(__VA_ARGS__)
// keep the code if a boolean macro is undefined
#define IFNDEF(macro, ...) MUXNDEF(macro, __KEEP, __IGNORE)(__VA_ARGS__)
// keep the code if a boolean macro is defined to 1
#define IFONE(macro, ...) MUXONE(macro, __KEEP, __IGNORE)(__VA_ARGS__)
// keep the code if a boolean macro is defined to 0
#define IFZERO(macro, ...) MUXZERO(macro, __KEEP, __IGNORE)(__VA_ARGS__)

// functional-programming-like macro (X-macro)
// apply the function `f` to each element in the container `c`
// NOTE1: `c` should be defined as a list like:
//   f(a0) f(a1) f(a2) ...
// NOTE2: each element in the container can be a tuple
#define MAP(c, f) c(f)

#define BITMASK(bits) ((1ull << (bits)) - 1)
#define BITS(x, hi, lo) (((x) >> (lo)) & BITMASK((hi) - (lo) + 1)) // similar to x[hi:lo] in verilog
#define SEXT(x, len) ({ struct { int64_t n : len; } __x = { .n = x }; (uint64_t)__x.n; })

#define ROUNDUP(a, sz)   ((((uintptr_t)a) + (sz) - 1) & ~((sz) - 1))
#define ROUNDDOWN(a, sz) ((((uintptr_t)a)) & ~((sz) - 1))

#define PG_ALIGN __attribute((aligned(4096)))

#if !defined(likely)
#define likely(cond)   __builtin_expect(cond, 1)
#define unlikely(cond) __builtin_expect(cond, 0)
#endif

// for AM IOE
#define io_read(reg) \
  ({ reg##_T __io_param; \
    ioe_read(reg, &__io_param); \
    __io_param; })

#define io_write(reg, ...) \
  ({ reg##_T __io_param = (reg##_T) { __VA_ARGS__ }; \
    ioe_write(reg, &__io_param); })

#endif

/**
 * @brief 对一个变量的位模式进行类型重解释，类似于 C++20 的 std::bit_cast。
 * @note  此宏使用了GCC/Clang的语句表达式扩展，以便在表达式中使用。
 * @param dest_type 目标类型。
 * @param src   源变量（不是指针）。
 * @return 一个类型为 dest_type 的新值，其位模式与 src 相同。
 */
#if __STDC_VERSION__ >= 201112L
#define BITCAST(dest_type, src) \
    ({ \
        _Static_assert(sizeof(dest_type) == sizeof(src), "Bitcast types must have the same size"); \
        dest_type dest; \
        memcpy(&dest, &src, sizeof(dest)); \
        dest; \
    })
#else
#define BITCAST(dest_type, src) \
    ({ \
        assert(sizeof(dest_type) == sizeof(src) && "Bitcast types must have the same size"); \
        dest_type dest; \
        memcpy(&dest, &src, sizeof(dest)); \
        dest; \
    })
#endif