使用stdint.h和ANSI的printf？ [英] Using stdint.h and ANSI printf?

问题描述

我正在写一个BIGNUM库，我想用有效的数据类型重新present数字。尤其是整数的数字，长的（如果严格双整数大小），中间再presentations加法和乘法的时候。

I'm writing a bignum library, and I want to use efficient data types to represent the digits. Particularly integer for the digit, and long (if strictly double the size of the integer) for intermediate representations when adding and multiplying.

我将用一些C99的功能，而是试图以符合ANSI C

I will be using some C99 functionality, but trying to conform to ANSI C.

目前我已经中我BIGNUM库如下：

Currently I have the following in my bignum library:

#include <stdint.h>

#if defined(__LP64__) || defined(__amd64) || defined(__x86_64) || defined(__amd64__) || defined(__amd64__) || defined(_LP64)
typedef uint64_t u_w;
typedef uint32_t u_hw;
#define BIGNUM_DIGITS 2048
#define U_HW_BITS 16
#define U_W_BITS 32
#define U_HW_MAX UINT32_MAX
#define U_HW_MIN UINT32_MIN
#define U_W_MAX UINT64_MAX
#define U_W_MIN UINT64_MIN
#else
typedef uint32_t u_w;
typedef uint16_t u_hw;
#define BIGNUM_DIGITS 4096
#define U_HW_BITS 16
#define U_W_BITS 32
#define U_HW_MAX UINT16_MAX
#define U_HW_MIN UINT16_MIN
#define U_W_MAX UINT32_MAX
#define U_W_MIN UINT32_MIN
#endif

typedef struct bn
{
        int sign;
        int n_digits; // #digits should exclude carry (digits = limbs)
        int carry;
        u_hw tab[BIGNUM_DIGITS];
} bn;

由于我没有写来写BIGNUM十进制的过程，我就来分析一下中间阵列和printf中每个数字的值。不过，我不知道用的printf要使用的转换说明。 preferably我想写信给终端数字连接以十六进制codeD。

As I haven't written a procedure to write the bignum in decimal, I have to analyze the intermediate array and printf the values of each digit. However I don't know which conversion specifier to use with printf. Preferably I would like to write to the terminal the digit encoded in hexadecimal.

根本的问题是，我想两个数据类型，一个是只要对方两次，还使用标准的转换说明的printf与使用它们。如果int是32位长是64位，但我不知道如何使用preprocessor保证这一点，当谈到时间，使用函数，如printf的单纯依靠标准类型的我不再这将是理想的知道如何使用。

The underlying issue is, that I want two data types, one that is twice as long as the other, and further use them with printf using standard conversion specifiers. It would be ideal if int is 32bits and long is 64bits but I don't know how to guarantee this using a preprocessor, and when it comes time to use functions such as printf that solely rely on the standard types I no longer know what to use.

推荐答案

您可以使用宏从＆LT; inttypes.h＆GT; 来助阵：

You could use the macros from <inttypes.h> to help out:

#if defined(__LP64__) || defined(__amd64) || defined(__x86_64) || defined(__amd64__) || defined(__amd64__) || defined(_LP64)
typedef uint64_t u_w;
typedef uint32_t u_hw;
#define BIGNUM_DIGITS 2048
#define U_HW_BITS 16
#define U_W_BITS 32
#define U_HW_MAX UINT32_MAX
#define U_HW_MIN UINT32_MIN
#define U_W_MAX UINT64_MAX
#define U_W_MIN UINT64_MIN
#define PRI_U_HW  PRIu32    // use for formatting a `u_hw` type
#define PRI_U_W   PRIu64    // use for formatting a `u_w` type
#else
typedef uint32_t u_w;
typedef uint16_t u_hw;
#define BIGNUM_DIGITS 4096
#define U_HW_BITS 16
#define U_W_BITS 32
#define U_HW_MAX UINT16_MAX
#define U_HW_MIN UINT16_MIN
#define U_W_MAX UINT32_MAX
#define U_W_MIN UINT32_MIN
#define PRI_U_HW  PRIu16    // use for formatting a `u_hw` type
#define PRI_U_W   PRIu32    // use for formatting a `u_w` type
#endif

然后：

printf( "some u_w variable: %" PRI_U_W "\n", u_w_var);    
printf( "some u_hw variable: %" PRI_U_HW "\n", u_hw_var);

他们不是pretty，但他们C99是怎么做的。

They aren't pretty, but they're how C99 does it.

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