📄 util.m
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%==============================================================%% File: util.m %% Author: Nagi B. F. MIKHAIL %% Date: April, 1995 %% Description: This file contains utility routines written in %% MOON's assembly to handle string operations & %% Input/Output. %%==============================================================%%%%--------------------------------------------------------------%% getint %%--------------------------------------------------------------%% Read an integer number from stdin. Read until a non digit char% is entered. Allowes (+) & (-) signs only as first char. The% digits are read in ASCII and transformed to numbers.% Entry : none.% Exit : result -> r1%getint align add r1,r0,r0 % Initialize input register (r1 = 0) add r2,r0,r0 % Initialize buffer's index i add r4,r0,r0 % Initialize sign flaggetint1 getc r1 % Input ch ceqi r3,r1,43 % ch = '+' ? bnz r3,getint1 % Branch if true (ch = '+') ceqi r3,r1,45 % ch = '-' ? bz r3,getint2 % Branch if false (ch != '-') addi r4,r0,1 % Set sign flag to true j getint1 % Loop to get next chgetint2 clti r3,r1,48 % ch < '0' ? bnz r3,getint3 % Branch if true (ch < '0') cgti r3,r1,57 % ch > '9' ? bnz r3,getint3 % Branch if true (ch > '9') sb getint9(r2),r1 % Store ch in buffer addi r2,r2,1 % i++ j getint1 % Loop if not finishedgetint3 sb getint9(r2),r0 % Store end of string in buffer (ch = '\0') add r2,r0,r0 % i = 0 add r1,r0,r0 % N = 0 add r3,r0,r0 % Initialize r3getint4 lb r3,getint9(r2) % Load ch from buffer bz r3,getint5 % Branch if end of string (ch = '\0') subi r3,r3,48 % Convert to number (M) muli r1,r1,10 % N *= 10 add r1,r1,r3 % N += M addi r2,r2,1 % i++ j getint4 % Loop if not finishedgetint5 bz r4,getint6 % Branch if sign flag false sub r1,r0,r1 % N = -Ngetint6 jr r15 % Return to the callergetint9 res 12 % Local buffer (12 bytes) align%%%--------------------------------------------------------------%% putint %%--------------------------------------------------------------%% Write an integer number to stdout. Transform the number into% ASCII string taking the sign into account.% Entry : integer number -> r1% Exit : none.%putint align add r2,r0,r0 % Initialize buffer's index i cge r3,r1,r0 % True if N >= 0 bnz r3,putint1 % Branch if True (N >= 0) sub r1,r0,r1 % N = -Nputint1 modi r4,r1,10 % Rightmost digit addi r4,r4,48 % Convert to ch divi r1,r1,10 % Truncate rightmost digit sb putint9(r2),r4 % Store ch in buffer addi r2,r2,1 % i++ bnz r1,putint1 % Loop if not finished bnz r3,putint2 % Branch if True (N >= 0) addi r3,r0,45 sb putint9(r2),r3 % Store '-' in buffer addi r2,r2,1 % i++ add r1,r0,r0 % Initialize output register (r1 = 0)putint2 subi r2,r2,1 % i-- lb r1,putint9(r2) % Load ch from buffer putc r1 % Output ch bnz r2,putint2 % Loop if not finished jr r15 % return to the callerputint9 res 12 % loacl buffer (12 bytes) align%%%--------------------------------------------------------------%% putstr %%--------------------------------------------------------------%% Write a string to stdout. Write char by char until end of % string.% Entry : address of string -> r1% Exit : none.% putstr align add r2,r0,r0 % Initialize output register (r2 = 0)putstr1 lb r2,0(r1) % Load ch from buffer bz r2,putstr2 % Branch if end of string (ch = '\0') putc r2 % Output ch addi r1,r1,1 % i++ j putstr1 % Loop if not finishedputstr2 jr r15 % Return to the caller align%%%--------------------------------------------------------------%% putsub %%--------------------------------------------------------------% % Write a substring to stdout. Write char by char until end of % substring.% Entry : address of substring -> r1% address of end of substring -> r3% Exit : none.% putsub align add r2,r0,r0 % Initialize output register (r2 = 0)putsub1 lb r2,0(r1) % Load ch from buffer putc r2 % Output ch ceq r2,r1,r3 % Current pos. is end of substring ? bnz r2,putsub2 % Branch if end of substring addi r1,r1,1 % i++ j putsub1 % Loop if not finishedputsub2 jr r15 % Return to the caller align%%%--------------------------------------------------------------%% getstr %%--------------------------------------------------------------%% Read a string from stdin. Read char by char until CR but do % not store CR.% Entry : address of string var. -> r1% Exit : address of string var. -> r1%getstr align add r2,r0,r0 % Initialize input register (r2 = 0) getc r2 % Input ch ceqi r3,r2,10 % ch = CR ? bnz r3,getstr1 % branch if true (ch = CR) sb 0(r1),r2 % Store ch in buffer addi r1,r1,1 % i++ j getstr % Loop if not finishedgetstr1 sb 0(r1),r0 % Store end of string (ch = '\0') jr r15 % Return to the caller align%%%--------------------------------------------------------------%% catstr %%--------------------------------------------------------------%% Append one string to another.% Entry : address of 1st string -> r1% address of 2nd string -> r2% Exit : address of concatenated strings -> r1%catstr align add r3,r0,r0 % r3 = 0catstr1 lb r3,0(r1) % Load ch from 1st string bz r3,catstr2 % Branch if end of string (ch = `\0') addi r1,r1,1 % i++ j catstr1 % Loop if not end of 1st stringcatstr2 lb r3,0(r2) % Load ch from 2nd string sb 0(r1),r3 % Store ch at the end of 1st string bz r3,catstr3 % Branch if end of 2nd string addi r2,r2,1 % j++ addi r1,r1,1 % i++ j catstr2 % Loop if not end of 2nd stringcatstr3 jr r15 % Return to the caller align%%%--------------------------------------------------------------%% catsub %%--------------------------------------------------------------%% Append a substring to a string.% Entry : address of string -> r1% address of substring -> r2% address of end of substring -> r4% Exit : address of concatenated strings -> r1% catsub align add r3,r0,r0 % r3 = 0catsub1 lb r3,0(r1) % Load ch from 1st string bz r3,catsub2 % Branch if end of string (ch = `\0') addi r1,r1,1 % i++ j catsub1 % Loop if not end of 1st stringcatsub2 lb r3,0(r2) % Load ch from substring sb 0(r1),r3 % Store ch at the end of 1st string bz r3,catsub4 % Branch if end of string ch addi r1,r1,1 % i++ ceq r3,r2,r4 % Check end of substring bnz r3,catsub3 % Branch if end of substring addi r2,r2,1 % j++ j catsub2 % Loop if not end of substringcatsub3 sb 0(r1),r0 % Store end of stringcatsub4 jr r15 % Return to the caller align%%%--------------------------------------------------------------%% eqstr %%--------------------------------------------------------------%% Check if string1 = string2.% Entry : address of string1 -> r1% address of string2 -> r2% Exit : r1 = 1 (true)% r1 = 0 (false)%eqstr align add r3,r0,r0 % Initialize r3 (r3 = 0) add r4,r0,r0 % Initialize r4 (r4 = 0)eqstr1 lb r3,0(r1) % Load ch1 from 1st string lb r4,0(r2) % Load ch2 from 2nd string ceq r5,r3,r4 % ch1 = ch2 ? bz r5,eqstr2 % Branch if false ceq r5,r3,r0 % ch1 = '\0' ? bnz r5,eqstr3 % Branch if true addi r1,r1,1 % i++ addi r2,r2,1 % j++ j eqstr1 % Loop if not finishedeqstr2 add r1,r0,r0 % Return false j eqstr4eqstr3 addi r1,r0,1 % Return trueeqstr4 jr r15 % Return to the caller align%%%--------------------------------------------------------------%% neqstr %%--------------------------------------------------------------%% Check if string1 != string2.% Entry : address of string1 -> r1% address of string2 -> r2% Exit : r1 = 1 (true)% r1 = 0 (false)% neqstr align add r3,r0,r0 % Initialize r3 (r3 = 0) add r4,r0,r0 % Initialize r4 (r4 = 0)neqstr1 lb r3,0(r1) % Load ch1 from 1st string lb r4,0(r2) % Load ch2 from 2nd string cne r5,r3,r4 % ch1 != ch2 ? bnz r5,neqstr3 % Branch if true ceq r5,r3,r0 % ch1 = '\0' ? bnz r5,neqstr2 % Branch if true addi r1,r1,1 % i++ addi r2,r2,1 % j++ j neqstr1 % Loop if not finishedneqstr2 add r1,r0,r0 % Return false j neqstr4neqstr3 addi r1,r0,1 % Return trueneqstr4 jr r15 % Return to the caller align%⌨️ 快捷键说明
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