如何在年龄计算程序中使用 MASM 汇编语言中的条件语句？
How to use conditional statements in MASM Assembly Language for an age calculating program?
我目前正在上大学汇编语言课程，给我的家庭作业是编写一个程序，其中可以使用出生年月日来 return 年龄. （当前的年月日在程序的早期定义。）
程序的主要部分是条件 if 语句，将输入的年份与当前年份、输入的月份与当前月份以及输入的日期与当前日期进行比较。
还考虑了一些特殊情况，例如输入未来的日期，或输入与当前年份相同的年份，或者即使您输入的日期与当前日期相同将在输出末尾添加“生日快乐”文本的当前日期。
想要的 input/output 将是：
Enter the year of your birth: **2002**
Enter the month of your birth: **4**
You are 19 years old
我得到的input/output是这样的：
Enter the year of your birth: **2002**
Enter the month of your birth: **4**
You are 4294965279 years old
我很确定我搞砸了我对 EAX 和 DWORD 的使用，但我并不肯定。
我在这个问题中包含了整个程序，以便您更好地理解我想要实现的目标。
任何有关我搞砸的地方的提示将不胜感激。
此外，请记住，这只是我在此 class 中的第三次作业，所以不要指望我知道任何高级 MASM 汇编语言术语或技术。
这是代码（为了方便起见，伪代码在右边）：
TITLE H03C (H03C.asm)
; William Sanacore
; 9/23/2021
; H03C
; Description: Write a program that calculates how old you are.
INCLUDE Irvine32.inc
.data
curYear DWORD ?
curMonth DWORD ?
curDay DWORD ?
yearMsg BYTE "Enter the year of your birth: ", 0
montMsg BYTE "Enter the month of your birth: ", 0
dayMsg BYTE "Enter the day of your birth: ", 0
lessyearMsg BYTE "You are less than one year old"
youAreMsg BYTE "You are ", 0
yearsOldMsg BYTE " years old", 0
yearsOldHBMsg BYTE " years old, Happy Birthday", 0
notBornMsg BYTE "You have not been born yet", 0
year DWORD ?
month DWORD ?
day DWORD ?
age DWORD ?
.code
main PROC ; Start
mov curYear, 2021 ; curYear = 2021
mov curMonth, 9 ; curMonth = 9
mov curDay, 23 ; curDay = 23
LEA EDX, yearMsg ; Print "Enter the year of your birth: "
call WriteString
call ReadDec ; Input year
mov year, DWORD
mov year, EAX ; IF year = curYear THEN
cmp EAX, curYear
jne ELSE1
LEA EDX, lessyearMsg ; Print "you are less than 1 year old"
call WriteString
jmp ENDIF1
ELSE1: ; ELSE
mov year, EAX ; IF year < curYear THEN
cmp EAX, curYear
jnl ELSE2
LEA EDX, montMsg ; Print "Enter the month of your birth: "
call WriteString
call ReadDec ; Input month
mov month, DWORD
mov year, EAX ; age = curYear - year
sub EAX, curYear
mov age, DWORD
mov month, EAX ; IF month > curMonth THEN
cmp EAX, curMonth
jng ELSE3
mov age, EAX ; age = age - 1
sub EAX, '1'
mov age, DWORD
LEA EDX, youAreMsg ; Print "you are "; age; " years old"
call WriteString
mov age, EAX
call WriteDec
LEA EDX, yearsOldMsg
call WriteString
jmp ENDIF2
ELSE3: ; ELSE
mov month, EAX ; IF month < curMonth THEN
cmp EAX, curMonth
jnl ELSE4
LEA EDX, youAreMsg ; Print "you are "; age; " years old"
call WriteString
mov age, EAX
call WriteDec
LEA EDX, yearsOldMsg
call WriteString
jmp ENDIF3
ELSE4: ; ELSE
LEA EDX, dayMsg ; Print "Enter day of your birth: "
call WriteString
call ReadDec ; Input day
mov day, DWORD
mov day, EAX ; IF day > curDay THEN
cmp EAX, curDay
jng ELSE5
mov age, EAX ; age = age - 1
sub EAX, '1'
mov age, DWORD
LEA EDX, youAreMsg ; Print "you are "; age; " years old"
call WriteString
mov age, EAX
call WriteDec
LEA EDX, yearsOldMsg
call WriteString
jmp ENDIF4
ELSE5: ; ELSE
mov day, EAX ; IF day < curDay THEN
cmp EAX, curDay
jnl ELSE6
LEA EDX, youAreMsg ; Print "you are "; age; " years old"
call WriteString
mov age, EAX
call WriteDec
LEA EDX, yearsOldMsg
call WriteString
jmp ENDIF5
ELSE6: ; ELSE
LEA EDX, youAreMsg ; Print "you are "; age; " years old, Happy Birthday"
call WriteString
mov age, EAX
call WriteDec
LEA EDX, yearsOldMsg
call WriteString
jmp ENDIF6
ENDIF6: ; ENDIF
call CRLF
exit
ENDIF5: ; ENDIF
call CRLF
exit
ENDIF4: ; ENDIF
call CRLF
exit
ENDIF3: ; ENDIF
call CRLF
exit
ELSE2: ; ELSE
LEA EDX, notBornMsg ; Print "you haven't been born yet"
call WriteString
ENDIF2: ; ENDIF
call CRLF
exit
ENDIF1: ; ENDIF
call CRLF
exit ; Stop
main ENDP
END main
You are 4294965279 years old
恭喜！请告诉我们您是如何应对的...
开个玩笑，代码有很多问题。下面列出了几个：
call ReadDec ; Input year
mov year, DWORD
mov year, EAX ; IF year = curYear THEN
cmp EAX, curYear
ReadDec 的结果在 EAX 寄存器中。 mov year, DWORD 指令没有意义！如果您写评论，请将它们放在它们所属的行上。
call ReadDec ; Input year
mov year, eax
cmp eax, curYear ; IF year = curYear THEN
call ReadDec ; Input month
mov month, DWORD
mov year, EAX ; age = curYear - year
sub EAX, curYear
mov age, DWORD
在您刚刚输入 月 的这部分代码中，您用这个 [= 破坏了已经建立的 年 22=] 指令！此代码还执行虚假计算“month - curYear”。
mov month, EAX ; IF month > curMonth THEN
cmp EAX, curMonth
目标是第一个操作数，源是第二个操作数。从 month 变量加载 EAX 寄存器需要：mov eax, month.
mov age, EAX ; age = age - 1
sub EAX, '1'
mov age, DWORD
三行，三个错误。左边是目的地，右边是源头。值“1”是 49，但您只需要 1。'DWORD' 本身没有任何意义。
mov eax, age ; Load from memory
sub eax, 1 ; Decrement
mov age, eax ; Store to memory
一个较短的版本是：dec age
LEA EDX, yearsOldMsg
call WriteString
jmp ENDIF6
最后的“生日快乐”部分忘记实际引用相关消息。
mov edx, OFFSET yearsOldHBMsg
call WriteString
jmp ENDIF6
总而言之，代码很难读，你重复了好几遍。也许是不同的方法？
这是 BASIC 中的程序。
Print "Enter the year of your birth: "
Input year
IF year = curYear THEN
Print "you are less than 1 year old"
ELSE
IF year < curYear THEN
Print "Enter the month of your birth: "
Input month
age = curYear - year
IF month > curMonth THEN
age = age - 1
Print "you are "; age; " years old"
ELSE
IF month < curMonth THEN
Print "you are "; age; " years old"
ELSE
Print "Enter day of your birth: "
Input day
IF day > curDay THEN
age = age - 1
Print "you are "; age; " years old"
ELSE
IF day < curDay THEN
Print "you are "; age; " years old"
ELSE
Print "you are "; age; " years old, Happy Birthday"
ENDIF
ENDIF
ENDIF
ENDIF
ELSE
Print "you haven't been born yet"
ENDIF
ENDIF
您正在尝试非常紧密地遵循 BASIC 代码，可能太紧密了！更好的策略是研究高级示例，找出其意图，然后尽可能高效地用汇编代码编写代码。下面是一个例子 'avoids advanced MASM assembly language terms or techniques':
mov curYear, 2021 ; curYear = 2021
mov curMonth, 9 ; curMonth = 9
mov curDay, 23 ; curDay = 23
mov edx, OFFSET yearMsg ; Print "Enter the year of your birth: "
call WriteString
call ReadDec ; Input year
mov ecx, curYear ; age = curYear - year
sub ecx, eax ; (*)
mov age, ecx
mov edx, OFFSET lessyearMsg ; "you are less than 1 year old"
jz finalMsg
mov edx, OFFSET notBornMsg ; "you haven't been born yet"
js finalMsg
mov esi, OFFSET yearsOldMsg
mov edx, OFFSET montMsg ; Print "Enter the month of your birth: "
call WriteString
call ReadDec ; Input month
mov month, eax
cmp eax, curMonth
jne maybeDec
mov edx, OFFSET dayMsg ; Print "Enter day of your birth: "
call WriteString
call ReadDec ; Input day
mov day, eax
cmp eax, curDay
jne maybeDec
mov esi, OFFSET yearsOldHBMsg ; " years old, Happy Birthday"
jmp fullMsg
maybeDec:
jb fullMsg ; (**)
dec age ; age = age - 1
fullMsg:
mov edx, OFFSET youAreMsg ; " you are"
call WriteString
mov eax, age
call WriteDec
mov edx, esi ; ESI={yearsOldMsg, yearsOldHBMsg}
finalMsg:
call WriteString
call CRLF
() 那些 mov <reg>, OFFSET <label> 指令比 lea <reg>, <label> 指令短一个字节。
(*) 无论如何都需要 age 计算。我们可以使用 SUB 指令的标志结果，而不是执行多个单独的 CMP。
(**) 请注意，我确实使用了 unsigned 操作。天和月是无符号数。
我目前正在上大学汇编语言课程，给我的家庭作业是编写一个程序，其中可以使用出生年月日来 return 年龄. （当前的年月日在程序的早期定义。）
程序的主要部分是条件 if 语句，将输入的年份与当前年份、输入的月份与当前月份以及输入的日期与当前日期进行比较。
还考虑了一些特殊情况，例如输入未来的日期，或输入与当前年份相同的年份，或者即使您输入的日期与当前日期相同将在输出末尾添加“生日快乐”文本的当前日期。
想要的 input/output 将是：
Enter the year of your birth: **2002**
Enter the month of your birth: **4**
You are 19 years old
我得到的input/output是这样的：
Enter the year of your birth: **2002**
Enter the month of your birth: **4**
You are 4294965279 years old
我很确定我搞砸了我对 EAX 和 DWORD 的使用，但我并不肯定。
我在这个问题中包含了整个程序，以便您更好地理解我想要实现的目标。
任何有关我搞砸的地方的提示将不胜感激。
此外，请记住，这只是我在此 class 中的第三次作业，所以不要指望我知道任何高级 MASM 汇编语言术语或技术。
这是代码（为了方便起见，伪代码在右边）：
TITLE H03C (H03C.asm)
; William Sanacore
; 9/23/2021
; H03C
; Description: Write a program that calculates how old you are.
INCLUDE Irvine32.inc
.data
curYear DWORD ?
curMonth DWORD ?
curDay DWORD ?
yearMsg BYTE "Enter the year of your birth: ", 0
montMsg BYTE "Enter the month of your birth: ", 0
dayMsg BYTE "Enter the day of your birth: ", 0
lessyearMsg BYTE "You are less than one year old"
youAreMsg BYTE "You are ", 0
yearsOldMsg BYTE " years old", 0
yearsOldHBMsg BYTE " years old, Happy Birthday", 0
notBornMsg BYTE "You have not been born yet", 0
year DWORD ?
month DWORD ?
day DWORD ?
age DWORD ?
.code
main PROC ; Start
mov curYear, 2021 ; curYear = 2021
mov curMonth, 9 ; curMonth = 9
mov curDay, 23 ; curDay = 23
LEA EDX, yearMsg ; Print "Enter the year of your birth: "
call WriteString
call ReadDec ; Input year
mov year, DWORD
mov year, EAX ; IF year = curYear THEN
cmp EAX, curYear
jne ELSE1
LEA EDX, lessyearMsg ; Print "you are less than 1 year old"
call WriteString
jmp ENDIF1
ELSE1: ; ELSE
mov year, EAX ; IF year < curYear THEN
cmp EAX, curYear
jnl ELSE2
LEA EDX, montMsg ; Print "Enter the month of your birth: "
call WriteString
call ReadDec ; Input month
mov month, DWORD
mov year, EAX ; age = curYear - year
sub EAX, curYear
mov age, DWORD
mov month, EAX ; IF month > curMonth THEN
cmp EAX, curMonth
jng ELSE3
mov age, EAX ; age = age - 1
sub EAX, '1'
mov age, DWORD
LEA EDX, youAreMsg ; Print "you are "; age; " years old"
call WriteString
mov age, EAX
call WriteDec
LEA EDX, yearsOldMsg
call WriteString
jmp ENDIF2
ELSE3: ; ELSE
mov month, EAX ; IF month < curMonth THEN
cmp EAX, curMonth
jnl ELSE4
LEA EDX, youAreMsg ; Print "you are "; age; " years old"
call WriteString
mov age, EAX
call WriteDec
LEA EDX, yearsOldMsg
call WriteString
jmp ENDIF3
ELSE4: ; ELSE
LEA EDX, dayMsg ; Print "Enter day of your birth: "
call WriteString
call ReadDec ; Input day
mov day, DWORD
mov day, EAX ; IF day > curDay THEN
cmp EAX, curDay
jng ELSE5
mov age, EAX ; age = age - 1
sub EAX, '1'
mov age, DWORD
LEA EDX, youAreMsg ; Print "you are "; age; " years old"
call WriteString
mov age, EAX
call WriteDec
LEA EDX, yearsOldMsg
call WriteString
jmp ENDIF4
ELSE5: ; ELSE
mov day, EAX ; IF day < curDay THEN
cmp EAX, curDay
jnl ELSE6
LEA EDX, youAreMsg ; Print "you are "; age; " years old"
call WriteString
mov age, EAX
call WriteDec
LEA EDX, yearsOldMsg
call WriteString
jmp ENDIF5
ELSE6: ; ELSE
LEA EDX, youAreMsg ; Print "you are "; age; " years old, Happy Birthday"
call WriteString
mov age, EAX
call WriteDec
LEA EDX, yearsOldMsg
call WriteString
jmp ENDIF6
ENDIF6: ; ENDIF
call CRLF
exit
ENDIF5: ; ENDIF
call CRLF
exit
ENDIF4: ; ENDIF
call CRLF
exit
ENDIF3: ; ENDIF
call CRLF
exit
ELSE2: ; ELSE
LEA EDX, notBornMsg ; Print "you haven't been born yet"
call WriteString
ENDIF2: ; ENDIF
call CRLF
exit
ENDIF1: ; ENDIF
call CRLF
exit ; Stop
main ENDP
END main
You are 4294965279 years old
恭喜！请告诉我们您是如何应对的...
开个玩笑，代码有很多问题。下面列出了几个：
call ReadDec ; Input year mov year, DWORD mov year, EAX ; IF year = curYear THEN cmp EAX, curYear
ReadDec 的结果在 EAX 寄存器中。 mov year, DWORD 指令没有意义！如果您写评论，请将它们放在它们所属的行上。
call ReadDec ; Input year
mov year, eax
cmp eax, curYear ; IF year = curYear THEN
call ReadDec ; Input month mov month, DWORD mov year, EAX ; age = curYear - year sub EAX, curYear mov age, DWORD
在您刚刚输入 月 的这部分代码中，您用这个 [= 破坏了已经建立的 年 22=] 指令！此代码还执行虚假计算“month - curYear”。
mov month, EAX ; IF month > curMonth THEN cmp EAX, curMonth
目标是第一个操作数，源是第二个操作数。从 month 变量加载 EAX 寄存器需要：mov eax, month.
mov age, EAX ; age = age - 1 sub EAX, '1' mov age, DWORD
三行，三个错误。左边是目的地，右边是源头。值“1”是 49，但您只需要 1。'DWORD' 本身没有任何意义。
mov eax, age ; Load from memory
sub eax, 1 ; Decrement
mov age, eax ; Store to memory
一个较短的版本是：dec age
LEA EDX, yearsOldMsg call WriteString jmp ENDIF6
最后的“生日快乐”部分忘记实际引用相关消息。
mov edx, OFFSET yearsOldHBMsg
call WriteString
jmp ENDIF6
总而言之，代码很难读，你重复了好几遍。也许是不同的方法？
这是 BASIC 中的程序。
Print "Enter the year of your birth: "
Input year
IF year = curYear THEN
Print "you are less than 1 year old"
ELSE
IF year < curYear THEN
Print "Enter the month of your birth: "
Input month
age = curYear - year
IF month > curMonth THEN
age = age - 1
Print "you are "; age; " years old"
ELSE
IF month < curMonth THEN
Print "you are "; age; " years old"
ELSE
Print "Enter day of your birth: "
Input day
IF day > curDay THEN
age = age - 1
Print "you are "; age; " years old"
ELSE
IF day < curDay THEN
Print "you are "; age; " years old"
ELSE
Print "you are "; age; " years old, Happy Birthday"
ENDIF
ENDIF
ENDIF
ENDIF
ELSE
Print "you haven't been born yet"
ENDIF
ENDIF
您正在尝试非常紧密地遵循 BASIC 代码，可能太紧密了！更好的策略是研究高级示例，找出其意图，然后尽可能高效地用汇编代码编写代码。下面是一个例子 'avoids advanced MASM assembly language terms or techniques':
mov curYear, 2021 ; curYear = 2021
mov curMonth, 9 ; curMonth = 9
mov curDay, 23 ; curDay = 23
mov edx, OFFSET yearMsg ; Print "Enter the year of your birth: "
call WriteString
call ReadDec ; Input year
mov ecx, curYear ; age = curYear - year
sub ecx, eax ; (*)
mov age, ecx
mov edx, OFFSET lessyearMsg ; "you are less than 1 year old"
jz finalMsg
mov edx, OFFSET notBornMsg ; "you haven't been born yet"
js finalMsg
mov esi, OFFSET yearsOldMsg
mov edx, OFFSET montMsg ; Print "Enter the month of your birth: "
call WriteString
call ReadDec ; Input month
mov month, eax
cmp eax, curMonth
jne maybeDec
mov edx, OFFSET dayMsg ; Print "Enter day of your birth: "
call WriteString
call ReadDec ; Input day
mov day, eax
cmp eax, curDay
jne maybeDec
mov esi, OFFSET yearsOldHBMsg ; " years old, Happy Birthday"
jmp fullMsg
maybeDec:
jb fullMsg ; (**)
dec age ; age = age - 1
fullMsg:
mov edx, OFFSET youAreMsg ; " you are"
call WriteString
mov eax, age
call WriteDec
mov edx, esi ; ESI={yearsOldMsg, yearsOldHBMsg}
finalMsg:
call WriteString
call CRLF
() 那些 mov <reg>, OFFSET <label> 指令比 lea <reg>, <label> 指令短一个字节。
(*) 无论如何都需要 age 计算。我们可以使用 SUB 指令的标志结果，而不是执行多个单独的 CMP。
(**) 请注意，我确实使用了 unsigned 操作。天和月是无符号数。