arm汇编编程范例.doc

一。if语句实例1/* *if(a 50) * puts(a 50);r0 r1 r2 r3 *else if(b a) * puts(b a); *else if(b 20) * puts(b 50.LC1:.stringb a.LC2:.stringb 10 & 10 & a 10 & a 10) & (a 10 & a 20);cmpr0, #10bleoutcmpr0, #20ldrltr0, .L0blltprintfout:pop pc从栈中取出lr存到pc中;.L0:.word.LC0if语句实例3, |运算.section.rodata.align2.LC0:.stringa 20.text.align2.globalmainmain:push lr上一个函数的返回地址压到栈中;mov r0, #15if( (a20) )puts(a 20);cmpr0, #10bltdocmpr0, #20bleoutdo:ldr r0, .L0blputsout:pop pc从栈中取出lr存到pc中;.L0:.word.LC0二，switch语句的实现1/* *char ch = A; * *switch (ch) * * case x: * break; * . * * */.section.rodata.align2.LC0:.asciival = %d 012000.text.align2.globalmainmain:stmfdsp!, fp, lraddfp, sp, #4subsp, sp, #16movr3, #65ch = A;strbr3, fp, #-5ldrbr3, fp, #-5 zero_extendqisi2strr3, fp, #-16int - switchldrr3, fp, #-16cmpr3, #45二分查找;beq.L5ldrr3, fp, #-16cmpr3, #45bgt.L9ldrr3, fp, #-16cmpr3, #2beq.L3ldrr3, fp, #-16cmpr3, #9beq.L4b.L11.L9:ldrr3, fp, #-16cmpr3, #97beq.L7ldrr3, fp, #-16cmpr3, #99beq.L8ldrr3, fp, #-16cmpr3, #65beq.L6b.L11.L7:ldrbr3, fp, #-5 zero_extendqisi2ldrr0, .L12movr1, r3blprintfb.L11.L8:ldrbr3, fp, #-5 zero_extendqisi2ldrr0, .L12movr1, r3blprintfb.L11.L3:ldrbr3, fp, #-5 zero_extendqisi2ldrr0, .L12movr1, r3blprintfb.L11.L4:ldrbr3, fp, #-5 zero_extendqisi2ldrr0, .L12movr1, r3blprintfb.L11.L5:ldrbr3, fp, #-5 zero_extendqisi2ldrr0, .L12movr1, r3blprintfb.L11.L6:ldrbr3, fp, #-5 zero_extendqisi2ldrr0, .L12movr1, r3blprintf.L11:subsp, fp, #4ldmfdsp!, fp, pc.L13:.align2.L12:.word.LC0switch语句的实现2(哈希实现).section.rodata.align2.LC0:.asciival = %d 012000.text.align2.globalmainmain:stmfdsp!, fp, lraddfp, sp, #4subsp, sp, #16movr3, #65strbr3, fp, #-5ldrbr3, fp, #-5 zero_extendqisi2subr3, r3, #59cmpr3, #8ldrlspc, pc, r3, asl #2b.L11.L9:.word.L3.word.L4.word.L11.word.L5.word.L6.word.L11.word.L7.word.L11.word.L8.L3:ldrbr3, fp, #-5 zero_extendqisi2ldrr0, .L12movr1, r3blprintfb.L11.L4:ldrbr3, fp, #-5 zero_extendqisi2ldrr0, .L12movr1, r3blprintfb.L11.L6:ldrbr3, fp, #-5 zero_extendqisi2ldrr0, .L12movr1, r3blprintfb.L11.L5:ldrbr3, fp, #-5 zero_extendqisi2ldrr0, .L12movr1, r3blprintfb.L11.L8:ldrbr3, fp, #-5 zero_extendqisi2ldrr0, .L12movr1, r3blprintfb.L11.L7:ldrbr3, fp, #-5 zero_extendqisi2ldrr0, .L12movr1, r3blprintf.L11:subsp, fp, #4ldmfdsp!, fp, pc.L13:.align2.L12:.word.LC0.sizemain, .-main.identGCC: (Sourcery G+ Lite 2008q3-72) 4.3.2.section.note.GNU-stack,%progbits三，while语句实现1/* *while(1) * * if(i = 10) * break; * printf(i = %d n, i); * i+; * */.section.rodata.align2.LC0:.stringi = %d n.text.align2.globalmainmain:push lr上一个函数的返回地址压到栈中;for(i = 0; i b.text.align2.globalmainmain:push lr上一个函数的返回地址压到栈中;loop:ldr r0, .L0blprintfblooppop pc从栈中取出lr存到pc中;.L0:.word.LC0for语句实现2/* *for (;) * * printf(a b); * sleep(1); * */.section.rodata.align2.LC0:.stringa b.text.align2.globalmainmain:push lr上一个函数的返回地址压到栈中;loop:ldr r0, .L0blputsmov r0, #1blsleepblooppop pc从栈中取出lr存到pc中;.L0:.word.LC0for语句实现3/* *for (i = 0; i b); * sleep(1); * * */.section.rodata.align2.LC0:.stringa b.text.align2.globalmainmain:push lr上一个函数的返回地址压到栈中;mov r4, #10loop:cmpr4, #0beqoutldr r0, .L0blputsmov r0, #1blsleepsubr4, r4, #1bloopout:pop pc从栈中取出lr存到pc中;.L0:.word.LC0for语句实现4/* *for (i = 10; i 0; i-) * * printf(a b); * sleep(1); * */.section.rodata.align2.LC0:.stringa b.text.align2.globalmainmain:push lr上一个函数的返回地址压到栈中;mov r1, #10loop:cmpr1, #0beqoutldr r0, .L0blputs - write r0 r1 r2 r3 puts r4 r5 r6 atpcs : r4-r14mov r0, #1blsleep sleep - alarmsubr1, r1, #1bloopout:pop pc从栈中取出lr存到pc中;.L0:.word.LC0for语句实现5/* *for(i = 0; i 10; i+) * * printf(i = %d n, i); * * */.section.rodata.align2.LC0:.stringi = %d n.text.align2.globalmainmain:push lr上一个函数的返回地址压到栈中;mov r4, #0loop:cmpr4, #10bgeoutldrr0, .L0mov r1, r4blprintfaddr4, #1bloopout:pop pc从栈中取出lr存到pc中;.L0:.word.LC0for语句实现6/* *for(i = 0; i 10; i+) * * for(j = 0; j 10; j+) * * printf(i = %d j = %d n, i, j); * * */.section.rodata.align2.LC0:.stringi = %d j = %dn.text.align2.globalmainmain:push lr上一个函数的返回地址压到栈中;mov r4, #0for:cmpr4, #10bgeoutmov r5, #0for1:cmpr5, #10bgeout1ldrr0, .L0mov r1, r4mov r2, r5blprintfaddr5, #1bfor1out1:addr4, #1bforout:pop pc从栈中取出lr存到pc中;.L0:.word.LC0do_wihle 语句实现/* *i = 0; *do * printf(i = %d n, i);