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[denper]

Ciao a tutti,
avrei la necessità di sapere cosa fa questa funzione in Assembly. Purtroppo io non ci capisco molto. Di certo è che esegue un calcolo di checkDigit su una stringa. Qualcuno di voi sa darmi una mano?

Grazie in anticipo.

; === S U B R O U T I N E ===
; Attributes: bp-based frame
; calcCheckDigit(char *, bool)
__Z14calcCheckDigitPcb

oldR4           = -0x14
oldR5           = -0x10
oldR6           = -0xC
oldR7           = -8
oldLR           = -4

PUSH    {R4-R7,LR}
ADD     R7, SP, #0xC
PUSH.W  {R8,R10}
TST.W   R1, #0xFF
ITE EQ
MOVEQ   R10, 0xFFFFFFFE
MOVNE.W R10, #0
MOVS    R6, #0
MOVS    R4, #1
MOV     R8, R0
MOV     R5, R6

loc_92FA
LDRSB.W R0, [R5,R8]
BL      __Z9fromASCIIc  ; fromASCII(char)
CMP     R0, #9
BLE     loc_931E
LDR     R2, =0x66666667
ADDS    R3, R0, #7
SMULL.W R0, R2, R3, R2
ASRS    R0, R3, #0x1F
RSB.W   R0, R0, R2,ASR#2
LSLS    R2, R0, #1
LSLS    R0, R0, #3
ADD     R0, R2
RSB.W   R0, R0, R3

loc_931E
ADDS    R5, #1
CMP     R5, #0x18
MLA.W   R6, R4, R0, R6
BEQ     loc_9342
LDR     R3, =0x66666667
ADDS    R2, R4, #1
SMULL.W R0, R1, R3, R2
ASRS    R3, R2, #0x1F
RSB.W   R4, R3, R1,ASR#2
LSLS    R1, R4, #1
LSLS    R3, R4, #3
ADD     R3, R1
RSB.W   R4, R3, R2
B       loc_92FA

loc_9342
LDR     R3, =0x66666667
ADD.W   R0, R6, R10
SMULL.W R1, R2, R3, R0
ASRS    R3, R0, #0x1F
RSB.W   R3, R3, R2,ASR#2
LSLS    R2, R3, #1
LSLS    R3, R3, #3
ADD     R3, R2
SUBS    R0, R0, R3
BL      __Z7toASCIIi    ; toASCII(int)
POP.W   {R8,R10}
POP     {R4-R7,PC}
; End of function calcCheckDigit(char *,bool)