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Include a file: Difference between revisions
add routine conversionAtoD to include file for arm assembly
(add routine conversion16 to file include arm64 assembly) |
(add routine conversionAtoD to include file for arm assembly) |
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Line 694:
iAdrsHexa: .int sHexa
iAdrsDeci: .int sDeci
/******************************************************************/
/* Convert a string to a number stored in a registry */
/******************************************************************/
/* r0 contains the address of the area terminated by 0 or 0A */
/* r0 returns a number */
conversionAtoD:
push {fp,lr} @ save 2 registers
push {r1-r7} @ save others registers
mov r1,#0
mov r2,#10 @ factor
mov r3,#0 @ counter
mov r4,r0 @ save address string -> r4
mov r6,#0 @ positive sign by default
mov r0,#0 @ initialization to 0
1: /* early space elimination loop */
ldrb r5,[r4,r3] @ loading in r5 of the byte located at the beginning + the position
cmp r5,#0 @ end of string -> end routine
beq 100f
cmp r5,#0x0A @ end of string -> end routine
beq 100f
cmp r5,#' ' @ space ?
addeq r3,r3,#1 @ yes we loop by moving one byte
beq 1b
cmp r5,#'-' @ first character is -
moveq r6,#1 @ 1 -> r6
beq 3f @ then move on to the next position
2: /* beginning of digit processing loop */
cmp r5,#'0' @ character is not a number
blt 3f
cmp r5,#'9' @ character is not a number
bgt 3f
/* character is a number */
sub r5,#48
ldr r1,iMaxi @ check the overflow of the register
cmp r0,r1
bgt 99f @ overflow error
mul r0,r2,r0 @ multiply par factor 10
add r0,r5 @ add to r0
3:
add r3,r3,#1 @ advance to the next position
ldrb r5,[r4,r3] @ load byte
cmp r5,#0 @ end of string -> end routine
beq 4f
cmp r5,#0x0A @ end of string -> end routine
beq 4f
b 2b @ loop
4:
cmp r6,#1 @ test r6 for sign
moveq r1,#-1
muleq r0,r1,r0 @ if negatif, multiply par -1
b 100f
99: /* overflow error */
ldr r0,=szMessErrDep
bl affichageMess
mov r0,#0 @ return zero if error
100:
pop {r1-r7} @ restaur other registers
pop {fp,lr} @ restaur 2 registers
bx lr @return procedure
/* constante program */
iMaxi: .int 1073741824
szMessErrDep: .asciz "Too large: overflow 32 bits.\n"
.align 4
/******************************************************************/
/* Converting a register to hexadecimal */
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