why does it use the movl instead of push ?!
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Published on 2010-12-26T17:42:35Z
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2010/12/26
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hi all. pay attention to this code :
#include <stdio.h>
void a(int a, int b, int c)
{
char buffer1[5];
char buffer2[10];
}
int main()
{
a(1,2,3);
}
after that :
gcc -S a.c
that command shows our source code in assembly.
now we can see in the main function, we never use "push" command to push the arguments of the a function into the stack. and it used "movel" instead of that
main:
pushl %ebp
movl %esp, %ebp
andl $-16, %esp
subl $16, %esp
movl $3, 8(%esp)
movl $2, 4(%esp)
movl $1, (%esp)
call a
leave
why does it happen? what's difference between them?
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