IBM―PC汇编语言程序设计(第二版)电子教案第六章

1第六章子程序结构过程定义伪操作子程序的调用与返回保存与恢复寄存器子程序的参数传送子程序的嵌套与递归21.过程定义伪操作过程名PROCNEAR(FAR)过程名ENDP（1）NEAR属性：调用程序和子程序在同一代码段中（段内调用）（2）FAR属性：调用程序和子程序不在同一代码段中（段间调用）...3codesegmentmainprocfar……callsubr1……retmainendpsubr1procnear……retsubr1endpcodeendssegxsegmentsubtprocfar……retsubtendp……callsubt……segxendssegysegment……callfarptrsubt……segyends4子程序调用：隐含使用堆栈保存返回地址callnearptrsubp(1)保存返回地址(2)转子程序callfarptrsubp(1)保存返回地址(2)转子程序子程序返回：ret2.子程序的调用与返回(SP)→(IP)(IP)(CS)(SP)→53.保存与恢复寄存器subtprocfarpushaxpushbxpushcxpushdx…………popdxpopcxpopbxpopaxretsubtendp6(1)通过寄存器传送参数(2)通过存储器传送参数(3)通过地址表传送参数地址(4)通过堆栈传送参数或参数地址(5)多个模块之间的参数传送4.子程序的参数传送7例：十六进制到十进制的转换（通过寄存器传送参数）hexidecsegment;1610assumecs:hexidecmainprocfarstart:pushdssubax,axpushaxrepeat:callhexibin;162callcrlfcallbinidec;210callcrlfjmprepeatretmainendp………………hexidecendsendstart8hexibinprocnearmovbx,0newchar:movah,1int21hsubal,30hjlexitcmpal,10jladd_tosubal,27hcmpal,0ahjlexitcmpal,10hjgeexitadd_to:movcl,4shlbx,clmovah,0addbx,axjmpnewcharexit:rethexibinendpbinidecprocnearmovcx,10000dcalldec_divmovcx,1000dcalldec_divmovcx,100dcalldec_divmovcx,10dcalldec_divmovcx,1dcalldec_divretbinidecendpdec_divprocnearmovax,bxmovdx,0divcxmovbx,dxmovdl,aladddl,30hmovah,2int21hretdec_divendp1ab5316162359例：累加数组中的元素（通过存储器传送参数）datasegmentarydw1,2,3,4,5,6,7,8,9,10countdw10sumdw?dataendscodesegmentmainprocfarassumecs:code,ds:datamovax,datamovds,axcallproaddmovax,4c00hint21hmainendpcodeendsendmainproaddprocnearpushaxpushcxpushsileasi,arymovcx,countxorax,axnext:addax,[si]addsi,2loopnextmovsum,axpopsipopcxpopaxretproaddendp10如果数据段定义如下：datasegmentarydw1,2,3,4,5,6,7,8,9,10countdw10sumdw?ary1dw10,20,30,40,50,60,70,80,90,100count1dw10sum1dw?dataends如果直接访问内存变量，那么累加数组ary和数组ary1中的元素不能用同一个子程序proadd。11例：累加数组中的元素（通过地址表传送参数地址）datasegmentarydw10,20,30,40,50,60,70,80,90,100countdw10sumdw?tabledw3dup(?);地址表dataendscodesegmentmainprocfarassumecs:code,ds:datapushdssubax,axpushaxmovax,datamovds,axmovtable,offsetarymovtable+2,offsetcountmovtable+4,offsetsummovbx,offsettablecallproaddretmainendp12proaddprocnearpushaxpushcxpushsipushdimovsi,[bx]movdi,[bx+2]movcx,[di]movdi,[bx+4]xorax,axnext:addax,[si]addsi,2loopnextmov[di],axpopdipopsipopcxpopaxretproaddendpcodeendsendmain30d40d50d60d70d80d90d100d10dary20d10dcountsumtable0000001400160018000000140016(bx)(si)(di)550d13例：累加数组中的元素（通过堆栈传送参数地址）datasegmentarydw10,20,30,40,50,60,70,80,90,100countdw10sumdw?dataendsstacksegmentdw100dup(?)toslabelwordstackends14code1segmentmainprocfarassumecs:code1,ds:data,ss:stackstart:movax,stackmovss,axmovsp,offsettosmovax,datamovds,axmovbx,offsetarypushbxmovbx,offsetcountpushbxmovbx,offsetsumpushbxcallfarptrproaddmovax,4c00hint21hmainendpcode1ends15code2segmentassumecs:code2proaddprocfarpushbpmovbp,sppushaxpushcxpushsipushdimovsi,[bp+0ah]movdi,[bp+8]movcx,[di]movdi,[bp+6]code2endsendstartxorax,axnext:addax,[si]addsi,2loopnextmov[di],axpopdipopsipopcxpopaxpopbpret6proaddendp(ip)(cs)sumcountarray(di)(si)(cx)(ax)(sp)(bp)(bp)(bp)+0ah(bp)+8(bp)+6tos16多个模块之间的参数传送：局部符号：在本模块中定义，在本模块中引用的符号外部符号：在某一模块中定义，在另一模块中引用的符号PUBLIC符号EXTRN符号:类型extrnproadd:far…………code1segmentstart:……callfarptrproadd……code1endsendstart;proadd1.asmpublicproadd…………code2segmentproaddprocfar……retproaddendpcode2endsend;proadd2.asm17例：;proadd1.asmextrnproadd:fardatasegmentcommonarydw1,2,3,4,5,6,7,8,9,10countdw10sumdw?dataendscode1segmentmainprocfarassumecs:code1,ds:datastart:movax,datamovds,axcallfarptrproaddmovah,4chint21hmainendpcode1endsendstart18;proadd2.asmpublicproadddatasegmentcommonarydw1,2,3,4,5,6,7,8,9,10countdw10sumdw?dataendscode2segmentproaddprocfarassumecs:code2,ds:datamovax,datamovds,axpushaxpushcxpushsileasi,arymovcx,countxorax,axnext:addax,[si]addsi,2loopnextmovsum,axpopsipopcxpopaxretproaddendpcode2endsend19子程序的嵌套：主程序子程序A子程序B递归子程序：n!＝n(n-1)(n-2)…13!＝3×2×1=65.子程序的嵌套与递归调用……callproc_A……proc_A……callproc_B……Callproc_Aretproc_B……ret20例：计算n!framestrucsave_bpdw?save_cs_ipdw2dup(?)ndw?result_addrdw?frameends;---------------------------------datasegmentn_vdw3resultdw?dataends;---------------------------------stacksegmentdw128dup(?)toslabelwordstackendsmovax,[bp].nmovbx,[bp].result_addr0!=1n!=n(n-1)!21codesegmentmainprocfarassumecs:code,ds:data,ss:stackstart:movax,stack；用户堆栈地址movss,axmovsp,offsettospushds；保存返回DOS地址subax,axpushaxmovax,data；数据段地址movds,axmovbx,offsetresult;结构数据入栈pushbxmovbx,n_vpushbxcallfarptrfactretmainendpcodeends22code1segmentassumecs:code1factprocfarpushbpmovbp,sppushbxpushaxmovbx,[bp].result_addrmovax,[bp].ncmpax,0jedonepushbxdecaxpushaxcallfarptrfactmovbx,[bp].result_addrmovax,[bx]mul[bp].njmpshortreturndone:movax,1return:mov[bx],axpopaxpopbxpopbpret4factendpcode1ends(AX)(BX)(BP)CODE中的(IP)CODE中的(CS)3RESULT的地址第1帧(AX)(BX)(BP)CODE1中的(IP)CODE1中的(CS)2RESULT的地址第2帧(AX)(BX)(BP)CODE1中的(IP)CODE1中的(CS)1RESULT的地址第3帧(AX)(BX)(BP)CODE1中的(IP)CODE1中的(CS)0RESULT的地址第4帧00FA00F200E400D600C8000000F200E400D623factprocnearpushaxpushbpmovbp,spmovax,[bp+6]cmpax,0jnefact1incaxjmpexitfact1:decaxpushaxcallfactpopaxmulwordptr[bp+6]exit:mov[bp+6],axpopbppopaxretfactendp例：计算n!movbx,n_vpushbxcall