.file "task1.c"
.intel_syntax noprefix
# GNU C17 (MinGW.org GCC Build-2) version 9.2.0 (mingw32)
# compiled by GNU C version 9.2.0, GMP version 6.1.2, MPFR version 4.0.2, MPC version 1.1.0, isl version isl-0.21-GMP
# GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
# options passed: -iprefix c:\mingw\bin\../lib/gcc/mingw32/9.2.0/ task1.c
# -masm=intel -mtune=generic -march=i586 -Og -fverbose-asm
# options enabled: -faggressive-loop-optimizations -fassume-phsa
# -fasynchronous-unwind-tables -fauto-inc-dec -fcombine-stack-adjustments
# -fcommon -fcompare-elim -fcprop-registers -fdefer-pop
# -fdelete-null-pointer-checks -fdwarf2-cfi-asm -fearly-inlining
# -feliminate-unused-debug-types -fforward-propagate
# -ffp-int-builtin-inexact -ffunction-cse -fgcse-lm -fgnu-runtime
# -fgnu-unique -fguess-branch-probability -fident -finline
# -finline-atomics -fipa-profile -fipa-pure-const -fipa-reference
# -fipa-reference-addressable -fipa-stack-alignment -fira-hoist-pressure
# -fira-share-save-slots -fira-share-spill-slots -fivopts
# -fkeep-inline-dllexport -fkeep-static-consts -fleading-underscore
# -flifetime-dse -flto-odr-type-merging -fmath-errno -fmerge-constants
# -fmerge-debug-strings -fomit-frame-pointer -fpeephole -fplt
# -fprefetch-loop-arrays -freg-struct-return -freorder-blocks
# -fsched-critical-path-heuristic -fsched-dep-count-heuristic
# -fsched-group-heuristic -fsched-interblock -fsched-last-insn-heuristic
# -fsched-rank-heuristic -fsched-spec -fsched-spec-insn-heuristic
# -fsched-stalled-insns-dep -fschedule-fusion -fsemantic-interposition
# -fset-stack-executable -fshow-column -fshrink-wrap
# -fshrink-wrap-separate -fsigned-zeros -fsplit-ivs-in-unroller
# -fsplit-wide-types -fssa-backprop -fstdarg-opt
# -fstrict-volatile-bitfields -fsync-libcalls -ftoplevel-reorder
# -ftrapping-math -ftree-builtin-call-dce -ftree-ccp -ftree-ch
# -ftree-coalesce-vars -ftree-copy-prop -ftree-cselim -ftree-dce
# -ftree-dominator-opts -ftree-dse -ftree-forwprop -ftree-fre
# -ftree-loop-if-convert -ftree-loop-im -ftree-loop-ivcanon
# -ftree-loop-optimize -ftree-parallelize-loops= -ftree-phiprop
# -ftree-reassoc -ftree-scev-cprop -ftree-sink -ftree-slsr -ftree-ter
# -funit-at-a-time -funwind-tables -fverbose-asm -fzero-initialized-in-bss
# -m32 -m80387 -m96bit-long-double -maccumulate-outgoing-args
# -malign-double -malign-stringops -mavx256-split-unaligned-load
# -mavx256-split-unaligned-store -mfancy-math-387 -mfp-ret-in-387
# -mieee-fp -mlong-double-80 -mms-bitfields -mno-red-zone -mno-sse4
# -mpush-args -msahf -mstack-arg-probe -mstv -mvzeroupper
.text
.def ___main; .scl 2; .type 32; .endef
.section .rdata,"dr"
LC0:
.ascii "Reverse number is: %d\0"
.text
.globl _main
.def _main; .scl 2; .type 32; .endef
_main:
LFB0:
.cfi_startproc
push ebp #
.cfi_def_cfa_offset 8
.cfi_offset 5, -8
mov ebp, esp #,
.cfi_def_cfa_register 5
push esi #
push ebx #
and esp, -16 #,
sub esp, 16 #,
.cfi_offset 6, -12
.cfi_offset 3, -16
# task1.c:2: int main(){
call ___main #
# task1.c:4: int tmp_num, reverse_num = 0;
mov ecx, 0 # reverse_num,
# task1.c:3: int num = 12345;
mov ebx, 12345 # num,
L2:
# task1.c:6: while(num>=1){
test ebx, ebx # num
jle L5 #,
# task1.c:7: tmp_num = num%10;
mov edx, 1717986919 # tmp88,
mov eax, ebx # tmp105, num
imul edx # tmp88
sar edx, 2 # tmp89,
mov eax, ebx # tmp90, num
sar eax, 31 # tmp90,
sub edx, eax # tmp_num, tmp90
mov esi, edx # tmp_num, tmp_num
lea edx, [edx+edx*4] # tmp93,
lea eax, [edx+edx] # tmp94,
sub ebx, eax # num, tmp94
# task1.c:8: reverse_num = reverse_num * 10 + tmp_num;
lea eax, [ecx+ecx*4] # tmp97,
lea ecx, [eax+eax] # tmp98,
# task1.c:8: reverse_num = reverse_num * 10 + tmp_num;
add ecx, ebx # reverse_num, tmp_num
# task1.c:9: num = num/10;
mov ebx, esi # num, tmp_num
jmp L2 #
L5:
# task1.c:12: printf("Reverse number is: %d", reverse_num);
mov DWORD PTR [esp+4], ecx #, reverse_num
mov DWORD PTR [esp], OFFSET FLAT:LC0 #,
call _printf #
# task1.c:14: }
mov eax, 0 #,
lea esp, [ebp-8] #,
pop ebx #
.cfi_restore 3
pop esi #
.cfi_restore 6
pop ebp #
.cfi_restore 5
.cfi_def_cfa 4, 4
ret
.cfi_endproc
LFE0:
.ident "GCC: (MinGW.org GCC Build-2) 9.2.0"
.def _printf; .scl 2; .type 32; .endef
Write, Run & Share Assembly code online using OneCompiler's Assembly online compiler for free. It's one of the robust, feature-rich online compilers for Assembly language. Getting started with the OneCompiler's Assembly compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as Assembly and start coding.
Assembly language(asm) is a low-level programming language, where the language instructions will be more similar to machine code instructions.
Every assembler may have it's own assembly language designed for a specific computers or an operating system.
Assembly language requires less execution time and memory. It is more helful for direct hardware manipulation, real-time critical applications. It is used in device drivers, low-level embedded systems etc.
Assembly language usually consists of three sections,
Data section
To initialize variables and constants, buffer size these values doesn't change at runtime.
bss section
To declare variables
text section
_start specifies the starting of this section where the actually code is written.
There are various define directives to allocate space for variables for both initialized and uninitialized data.
variable-name define-directive initial-value
| Define Directive | Description | Allocated Space |
|---|---|---|
| DB | Define Byte | 1 byte |
| DW | Define Word | 2 bytes |
| DD | Define Doubleword | 4 bytes |
| DQ | Define Quadword | 8 bytes |
| DT | Define Ten Bytes | 10 bytes |
| Define Directive | Description |
|---|---|
| RESB | Reserve a Byte |
| RESW | Reserve a Word |
| RESD | Reserve a Doubleword |
| RESQ | Reserve a Quadword |
| REST | Reserve a Ten Bytes |
Constants can be defined using
CONSTANT_NAME EQU regular-exp or value
%assign constant_name value
%define constant_name value
Loops are used to iterate a set of statements for a specific number of times.
mov ECX,n
L1:
;<loop body>
loop L1
where n specifies the no of times loops should iterate.
Procedure is a sub-routine which contains set of statements. Usually procedures are written when multiple calls are required to same set of statements which increases re-usuability and modularity.
procedure_name:
;procedure body
ret