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> Windows > Double Output problem |
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macomics 23 Apr 2026, 17:47
1)
Code: mov eax, ecx
call print_frac_fixed 2) Code: print_frac_fixed: sub rsp, 40h mov ebx, 100000 ; 6 digits fixed scale lea rsi, [buffer+32] mov byte [rsi], 0 .loopf: xor edx, edx div ebx add dl, '0' dec rsi mov [rsi], dl mov ebx, ebx shr ebx, 1 cmp ebx, 0 jne .loopf mov rcx, rsi call [printf] add rsp, 40h ret 2.2) After dividing by a large number, you should not take the remainder, but the quotient. 2.3) To move to the next digit, the divisor must be divided by the base of the number system. You're dividing by 2, not 10. Code: ; ========================================================= ; FRACTION PRINT ; ========================================================= print_frac_fixed: sub rsp, 40h mov ebx, 100000 ; 6 digits fixed scale lea rsi, [buffer] .loopf: xor edx, edx div ebx add al, '0' mov [rsi], al inc rsi ; mov ebx, ebx mov eax, ebx mov ebx, edx xor edx, edx mov ecx, 10 ; shr ebx, 1 div ecx mov edx, eax ; !!! OR xchg ebx, eax mov eax, ebx mov ebx, edx cmp ebx, 0 jne .loopf mov byte [rsi], 0 lea rcx, [buffer] call [printf] add rsp, 40h ret |
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23 Apr 2026, 17:47 |
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AsmGuru62 23 Apr 2026, 20:06
As far as I know, scanf/printf functions (inside MSVCRT.DLL) already have all the converting capabilities: from text into double and back.
So, why use your own code to do all the conversions? |
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23 Apr 2026, 20:06 |
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frankobach26 24 Apr 2026, 11:35
Thank you both for Help. I am quite new with fASM. I haven't managed to build a running correct result. Little Thing IS still wrong. Thanks.
Update: second example is running fine. All OK Here. Code: ; nearly good , input 5.7 + 6.8 -> 12.§59104 ; § sign is not welcome ; format PE64 console entry start include 'win64a.inc' section '.data' data readable writeable num1 dq ? num2 dq ? result dq ? fmt_in db "%lf %lf",0 msg db "Zahlen eingeben:",13,10,0 outmsg db "Summe = ",0 dot db ".",0 nl db 13,10,0 scale dq 1000000.0 section '.bss' readable writeable buffer rb 64 section '.code' code readable executable start: sub rsp, 28h ; INPUT lea rcx, [msg] call [printf] lea rcx, [fmt_in] lea rdx, [num1] lea r8, [num2] call [scanf] ; CALCULATION (korrekt) movsd xmm0, [num1] addsd xmm0, [num2] ; ===================================================== ; SPLIT CORRECTLY ; ===================================================== cvttsd2si eax, xmm0 ; integer part mov ebx, eax cvtsi2sd xmm1, eax subsd xmm0, xmm1 ; fractional part (0.xxxx) mulsd xmm0, [scale] cvttsd2si ecx, xmm0 ; 6 decimals ; ===================================================== ; OUTPUT ; ===================================================== lea rcx, [outmsg] call [printf] mov eax, ebx call print_int lea rcx, [dot] call [printf] ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; mov eax, ecx ; no ? ; mov eax, edi ; ??? call print_frac_fixed ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; lea rcx, [nl] call [printf] call [getchar] call [getchar] add rsp, 28h xor ecx, ecx call [ExitProcess] ; ========================================================= ; INTEGER PRINT ; ========================================================= print_int: sub rsp, 40h mov ebx, 10 lea rsi, [buffer+32] mov byte [rsi], 0 .loop: xor edx, edx div ebx add dl, '0' dec rsi mov [rsi], dl test eax, eax jnz .loop mov rcx, rsi call [printf] add rsp, 40h ret ; ========================================================= ; FRACTION PRINT ; ========================================================= print_frac_fixed: sub rsp, 40h mov ebx, 100000 ; 6 digits fixed scale lea rsi, [buffer] .loopf: xor edx, edx div ebx add al, '0' mov [rsi], al inc rsi ; mov ebx, ebx mov eax, ebx mov ebx, edx xor edx, edx mov ecx, 10 ; shr ebx, 1 div ecx mov edx, eax ; !!! OR xchg ebx, eax mov eax, ebx mov ebx, edx cmp ebx, 0 jne .loopf mov byte [rsi], 0 lea rcx, [buffer] call [printf] add rsp, 40h ret section '.idata' import data readable library kernel32,'kernel32.dll',\ msvcrt,'msvcrt.dll' import kernel32,\ ExitProcess,'ExitProcess' import msvcrt,\ printf,'printf',\ scanf,'scanf',\ getchar,'getchar' New Update this example works: Code: ; GO: 2.4 + 4.8 -> 7.200000, chill format PE64 console entry start include 'win64a.inc' section '.data' data readable writeable num1 dq ? num2 dq ? fmt_in db "%lf %lf",0 msg db "Zahlen eingeben:",13,10,0 outmsg db "Summe = ",0 dot db ".",0 nl db 13,10,0 scale dq 1000000.0 rounder dq 0.5 section '.bss' readable writeable buffer rb 64 section '.code' code readable executable start: sub rsp, 28h ; INPUT lea rcx, [msg] call [printf] lea rcx, [fmt_in] lea rdx, [num1] lea r8, [num2] call [scanf] ; =============================== ; CALCULATION (ROBUST) ; =============================== movsd xmm0, [num1] addsd xmm0, [num2] ; scale first! mulsd xmm0, [scale] addsd xmm0, [rounder] cvttsd2si rax, xmm0 mov rbx, 1000000 xor rdx, rdx div rbx ; rax = int, rdx = frac mov r12, rax ; save integer mov r13, rdx ; save fraction ; =============================== ; OUTPUT ; =============================== lea rcx, [outmsg] call [printf] mov rax, r12 call print_int64 lea rcx, [dot] call [printf] mov rax, r13 call print_frac6 lea rcx, [nl] call [printf] call [getchar] call [getchar] add rsp, 28h xor ecx, ecx call [ExitProcess] ; ================================== ; PRINT INTEGER (64-bit safe) ; ================================== print_int64: push rbx push rsi sub rsp, 40h mov rbx, 10 lea rsi, [buffer+32] mov byte [rsi], 0 .loop: xor rdx, rdx div rbx add dl, '0' dec rsi mov [rsi], dl test rax, rax jnz .loop mov rcx, rsi call [printf] add rsp, 40h pop rsi pop rbx ret ; ================================== ; PRINT FRACTION (6 digits) ; ================================== print_frac6: push rbx push rsi sub rsp, 40h mov rbx, 10 lea rsi, [buffer+16] mov byte [rsi], 0 mov rcx, 6 .loopf: xor rdx, rdx div rbx add dl, '0' dec rsi mov [rsi], dl dec rcx jnz .loopf mov rcx, rsi call [printf] add rsp, 40h pop rsi pop rbx ret section '.idata' import data readable library kernel32,'kernel32.dll',\ msvcrt,'msvcrt.dll' import kernel32,\ ExitProcess,'ExitProcess' import msvcrt,\ printf,'printf',\ scanf,'scanf',\ getchar,'getchar' |
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24 Apr 2026, 11:35 |
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macomics 24 Apr 2026, 12:55
Code: ; nearly good , input 5.7 + 6.8 -> 12.§59104 ; § sign is not welcome ; format PE64 console entry start include 'win64a.inc' section '.data' data readable writeable num1 dq ? num2 dq ? result dq ? fmt_in db "%lf %lf",0 msg db "Zahlen eingeben:",13,10,0 outmsg db "Summe = ",0 dot db ".",0 nl db 13,10,0 scale dq 1000000.0 section '.bss' readable writeable buffer rb 64 section '.code' code readable executable start: sub rsp, 28h ; INPUT lea rcx, [msg] call [printf] lea rcx, [fmt_in] lea rdx, [num1] lea r8, [num2] call [scanf] ; CALCULATION (korrekt) movsd xmm0, [num1] addsd xmm0, [num2] ; ===================================================== ; SPLIT CORRECTLY ; ===================================================== cvttsd2si eax, xmm0 ; integer part mov ebx, eax cvtsi2sd xmm1, eax subsd xmm0, xmm1 ; fractional part (0.xxxx) mulsd xmm0, [scale] ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; cvttsd2si ecx, xmm0 ; 6 decimals cvttsd2si edi, xmm0 ; 6 decimals ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; ===================================================== ; OUTPUT ; ===================================================== lea rcx, [outmsg] call [printf] mov eax, ebx call print_int lea rcx, [dot] call [printf] ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; mov eax, ecx ; no ? mov eax, edi ; ??? call print_frac_fixed ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; lea rcx, [nl] call [printf] call [getchar] call [getchar] add rsp, 28h xor ecx, ecx call [ExitProcess] ; ========================================================= ; INTEGER PRINT ; ========================================================= print_int: sub rsp, 40h mov ebx, 10 lea rsi, [buffer+32] mov byte [rsi], 0 .loop: xor edx, edx div ebx add dl, '0' dec rsi mov [rsi], dl test eax, eax jnz .loop mov rcx, rsi call [printf] add rsp, 40h ret ; ========================================================= ; FRACTION PRINT ; ========================================================= print_frac_fixed: sub rsp, 40h mov ebx, 100000 ; 6 digits fixed scale lea rsi, [buffer] .loopf: xor edx, edx div ebx add al, '0' mov [rsi], al inc rsi ; mov ebx, ebx mov eax, ebx mov ebx, edx xor edx, edx mov ecx, 10 ; shr ebx, 1 div ecx mov edx, eax ; !!! OR xchg ebx, eax mov eax, ebx mov ebx, edx cmp ebx, 0 jne .loopf mov byte [rsi], 0 lea rcx, [buffer] call [printf] add rsp, 40h ret section '.idata' import data readable library kernel32,'kernel32.dll',\ msvcrt,'msvcrt.dll' import kernel32,\ ExitProcess,'ExitProcess' import msvcrt,\ printf,'printf',\ scanf,'scanf',\ getchar,'getchar' |
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24 Apr 2026, 12:55 |
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AsmGuru62 24 Apr 2026, 15:56
Also, you can just use MSVCRT and good old FPU (more precision than fancy XMM):
Code: format PE64 CONSOLE 5.0 entry start stack 4000h, 4000h include 'Win64A.Inc' ; --------------------------------------------------------------------------- section '.data' data readable writeable Value1 dq 0 Value2 dq 0 Summary dq 0 Prompt db ' Enter two float point values: ',0 Added db 0Dh,0Ah,' Sum of these values:',0Dh,0Ah db '%s %16.8lf',0Dh,0Ah db '%s %16.8lf',0Dh,0Ah db '%s %16.8lf',0Dh,0Ah,0 InFormat db '%lf %lf',0 SkipBlanks db ' ',0 ; --------------------------------------------------------------------------- section '.code' code readable executable ; --------------------------------------------------------------------------- ; PROGRAM ENTRY POINT ; --------------------------------------------------------------------------- align 16 start: push rax ; align stack on 16 invoke printf, Prompt invoke scanf, InFormat, Value1, Value2 fld [Value1] fadd [Value2] fstp [Summary] mov r10, SkipBlanks invoke printf, Added, r10, [Value1], r10, [Value2], r10, [Summary] invoke ExitProcess, 0 ; --------------------------------------------------------------------------- section '.idata' import data readable writeable library kernel32,'KERNEL32.DLL',msvcrt,'MSVCRT.DLL' include 'API\Kernel32.Inc' import msvcrt,scanf,'scanf',printf,'printf' Output: Code: Enter two float point values: 8274.98398 1e2 Sum of these values: 8274.98398000 100.00000000 8374.98398000 |
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24 Apr 2026, 15:56 |
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