Empty string: Difference between revisions
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(Add task to Arm assembly Raspberry) |
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-- str is not empty |
-- str is not empty |
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end if |
end if |
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</lang> |
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=={{header|ARM Assembly}}== |
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{{works with|as|Raspberry Pi}} |
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<lang ARM Assembly> |
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/* ARM assembly Raspberry PI */ |
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/* program strEmpty.s */ |
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/* Constantes */ |
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.equ STDOUT, 1 @ Linux output console |
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.equ EXIT, 1 @ Linux syscall |
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.equ WRITE, 4 @ Linux syscall |
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/* Initialized data */ |
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.data |
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szNotEmptyString: .asciz "String is not empty. \n" |
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szEmptyString: .asciz "String is empty. \n" |
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@ empty string |
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szString: .asciz "" @ with zero final |
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szString1: .asciz "A" @ with zero final |
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/* UnInitialized data */ |
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.bss |
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/* code section */ |
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.text |
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.global main |
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main: /* entry of program */ |
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push {fp,lr} /* saves 2 registers */ |
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@ load string |
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ldr r1,iAdrszString |
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ldrb r0,[r1] @ load first byte of string |
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cmp r0,#0 @ compar with zero ? |
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bne 1f |
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ldr r0,iAdrszEmptyString |
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bl affichageMess |
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b 2f |
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1: |
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ldr r0,iAdrszNotEmptyString |
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bl affichageMess |
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/* second string */ |
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2: |
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@ load string 1 |
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ldr r1,iAdrszString1 |
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ldrb r0,[r1] @ load first byte of string |
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cmp r0,#0 @ compar with zero ? |
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bne 3f |
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ldr r0,iAdrszEmptyString |
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bl affichageMess |
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b 100f |
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3: |
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ldr r0,iAdrszNotEmptyString |
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bl affichageMess |
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b 100f |
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100: /* standard end of the program */ |
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mov r0, #0 @ return code |
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pop {fp,lr} @restaur 2 registers |
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mov r7, #EXIT @ request to exit program |
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swi 0 @ perform the system call |
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iAdrszString: .int szString |
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iAdrszString1: .int szString1 |
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iAdrszNotEmptyString: .int szNotEmptyString |
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iAdrszEmptyString: .int szEmptyString |
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/******************************************************************/ |
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/* display text with size calculation */ |
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/******************************************************************/ |
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/* r0 contains the address of the message */ |
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affichageMess: |
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push {fp,lr} /* save registres */ |
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push {r0,r1,r2,r7} /* save others registers */ |
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mov r2,#0 /* counter length */ |
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1: /* loop length calculation */ |
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ldrb r1,[r0,r2] /* read octet start position + index */ |
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cmp r1,#0 /* if 0 its over */ |
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addne r2,r2,#1 /* else add 1 in the length */ |
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bne 1b /* and loop */ |
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/* so here r2 contains the length of the message */ |
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mov r1,r0 /* address message in r1 */ |
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mov r0,#STDOUT /* code to write to the standard output Linux */ |
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mov r7, #WRITE /* code call system "write" */ |
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swi #0 /* call systeme */ |
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pop {r0,r1,r2,r7} /* restaur others registers */ |
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pop {fp,lr} /* restaur des 2 registres */ |
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bx lr /* return */ |
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</lang> |
</lang> |
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