"fh"是什么?后缀表示类似"38fh"的数字.在英特尔大会上 [英] What does the "fh" suffix mean on a number like "38fh" in Intel assembly

问题描述

我已经在网上搜索了所有内容，但是在以下说明和eax 38fh 中找不到"fh"的含义.我知道"h"代表十六进制，"d"代表十进制，但是我从未见过fh.

I've searched all over the web, but I couldn't find what the "fh" means in the following instruction and eax, 38fh. I know that "h" stands for hexadecimal and "d" for decimal, but I've never seen fh before.

推荐答案

如果Intel汇编程序(即 MASM )令牌以数字(0到9)开头，则假定为整个令牌是一个值.如果该值以 h 结尾，则汇编程序会认为它是 H 十进制.

If an Intel assembler (ie. MASM) token starts with a number (0 to 9) then it is assumed to be that the entire token is a value. If the value ends with an h the assembler assumes it is Hexadecimal.

在您的情况下， 38fh 以数字开头，因此假定它是一个值.在您的情况下，令牌的末尾是 h (或 H )，因此将其视为十六进制数.因此 38f 被视为十六进制值. f 恰好是一个有效的十六进制数字. 38f 的十进制为911，二进制的为1110001111.

In your case 38fh starts with a number so it is assumed to be a value. The end of the token in your case is h(or H) so it is treated as hexadecimal number. So 38f is treated as a hexadecimal value. The f just happens to be a valid hexadecimal digit. 38f is 911 in decimal and 1110001111 in binary.

如果您有像 f8h 这样的令牌，则确实会出现问题.由于它以字母(不是0到9的数字)开头，因此将被视为标识符或符号.如果它以和eax，f8h 出现，则可能会导致某种形式的语法错误.一个人可能会遇到的问题-如果十六进制值以 A 到 F 的字母开头，如何使用后缀 h 表示它?很简单，只需在前面放置一个0.这将有效和eax，0f8h .

A problem does arise if you have a token like f8h. Because it starts with a letter (not a digit 0 to 9) it will be treated as an identifier or symbol. This will likely lead to some form of syntax error if it appeared as and eax, f8h . The question one may have - if a hexadecimal value starts with a letter A to F how can I represent it using an h suffix? Simple, just place a 0 on the front. This would work and eax, 0f8h .

正如Fifoernik指出的，一个窍门是使用另一种大写字母使后缀突出: 38Fh .对于新手来说，汇编程序很容易看到 f 是十六进制数字，如果将其改成大写的 F ，而将后缀字符'h'保留为小写

As Fifoernik pointed out One trick would be to use a different capitalization to make the suffix stand out: 38Fh . It might have been easier for a human new to assembler to see that f was a hexadecimal digit had it been made upper case F while leaving the suffix character 'h' lower case.

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