ARM汇编多寄存器寻址

时间:2021-08-25 08:04:12

原文转自:http://hi.baidu.com/mugua/item/c43f37cc55a75d35ee4665e6

多寄存器和堆栈寻址的用法:多寄存器寻址:LDMIA,LDMIB,STMIA,STMIB,LDMDA,LDMDB,STMDA,STMDB;
堆栈寻址:LDMFA,LDMFD,STMFA,STMFD,LDMEA,LDMED,STMEA,STMED;

弄清堆栈寻址的SP的变化:LDMFA,LDMFD,STMFA,STMFD,LDMEA,LDMED,STMEA,STMED;

IA: 每次传送后地址加4;
IB: 每次传送前地址加4;
DA: 每次传送后地址减4;
DB: 每次传送前地址减4;
FD: 满递减堆栈;
ED: 空递减堆栈;
FA: 满递增堆栈;
EA: 空递增堆栈。




1、多寄存器寻址:
LDMIA R0!,{R1-R4}  

                               ;R1<----[R0]
                               ;R2<----[R0+4]
                               ;R3<----[R0+8]
                               ;R4<----[R0+12]         

例如:

所有的示例指令执行前:
mem32[0x1000C] = 0x04
mem32[0x10008] = 0x03
mem32[0x10004] = 0x02
mem32[0x10000] = 0x01
r0 = 0x00010010
r1 = 0x00000000
r3 = 0x00000000
r4 = 0x00000000
1) ldmia r0!, {r1-r3} 2) ldmib r0!, {r1-r3}
执行后:                      执行后:
r0 = 0x0010001C    r0 = 0x0010001C
r1 = 0x01                   r1 = 0x02
r2 = 0x02                   r2 = 0x03
r3 = 0x03                   r3 = 0x04


2、堆栈寻址:
STMFD入栈指令,相当于STMDB
STMFD SP!,{R2-R4}                            ;[SP-4]<---R4
                                             ;[SP-8]<---R3 
                                             ;[SP-12]<---R2   
LDMFD出栈指令,相当于LDMIA
LDMFD SP!,{R6-R8}                ;R6<----[SP]
                                 ;R7<----[SP+4]
                                 ;R8<----[SP+8]