RosettaCodeData/Task/Factorial/RISC-V-Assembly/factorial.asm
2026-04-30 12:34:36 -04:00

131 lines
3.7 KiB
NASM

# riscv assembly raspberry pico2 rp2350
# program factorial.s
# connexion putty com3
/*********************************************/
/* CONSTANTES */
/********************************************/
/* for this file see risc-v task include a file */
.include "../../constantesRiscv.inc"
/****************************************************/
/* MACROS */
/****************************************************/
#.include "../ficmacrosriscv.inc" # for debugging only
/*******************************************/
/* INITIALED DATAS */
/*******************************************/
.data
szMessStart: .asciz "Program riscv start.\r\n"
szMessEnd: .asciz "\nProgram end OK.\r\n"
szCariageReturn: .asciz "\r\n"
szMessLargeNumber: .asciz "Number N to large. \n"
szMessNegNumber: .asciz "Number N is negative. \n"
szMessResult: .ascii "Resultat = " # message result
.align 2
/*******************************************/
/* UNINITIALED DATA */
/*******************************************/
.bss
.align 2
sConvArea: .skip 24
/********************************...-..--*****/
/* SECTION CODE */
/**********************************************/
.text
.global main
main:
call stdio_init_all # général init
1: # start loop connexion
li a0,0 # raz argument register
call tud_cdc_n_connected # waiting for USB connection
beqz a0,1b # return code = zero ?
la a0,szMessStart # message address
call writeString # display message
li a0,-10
call factorial #
li a0,0
call factorial #
li a0,10
call factorial #
la a0,szMessEnd
call writeString
call getchar
100: # final loop
j 100b
/**********************************************/
/* compute factorial */
/**********************************************/
/* a0 value */
factorial: # INFO: factorial
addi sp, sp, -4 # reserve stack
sw ra, 0(sp)
bltz a0,99f # is negative ?
li t0,1
ble a0,t0,1f # is 0 or 1
call computeFactorial
li t0,-1 # error overflow ?
beq a0,t0,98f
1: # display result
la a1,sConvArea
call conversion10
la a0,szMessResult
call writeString
la a0,sConvArea
call writeString
la a0,szCariageReturn
call writeString
j 100f
98:
la a0,szMessLargeNumber
call writeString
j 100f
99:
la a0,szMessNegNumber
call writeString
j 100f
100:
lw ra, 0(sp)
addi sp, sp, 4
ret
/**********************************************/
/* compute factorial */
/**********************************************/
/* a0 value */
computeFactorial: # INFO:computeFactorial
addi sp,sp, -8 # reserve stack
sw ra,0(sp)
sw s0,4(sp)
li t0,1
beq a0,t0,100f # if n = 1 return
mv s0,a0
addi a0,a0,-1
call computeFactorial
li t0,-1 # error overflow ?
beq a0,t0,100f
mulh t0,a0,s0 # compute half high 32 bits
beqz t0,1f # is ok if result is zero
li a0,-1 # error overflow
j 100f
1:
mul a0,a0,s0 # multiplication
100:
lw ra,0(sp)
lw s0,4(sp)
addi sp,sp, 8
ret
/************************************/
/* file include Fonctions */
/***********************************/
/* for this file see risc-v task include a file */
.include "../../includeFunctions.s"