The assembly functions with commented c version:
/*
int f (int x)
{
return x+2;
}
void map2 (int* one, int * another, int n)
{
int i;
for (i=0; i<n; i++)
*(another+i) = f(*(one+i));
}
*/
.text
.globl f
f:
/********************************** prologue *************************************/
pushl %ebp
movl %esp, %ebp
/********************************************************************************/
movl 8(%ebp), %eax
addl $2, %eax
/************************************* end **************************************/
movl %ebp, %esp
popl %ebp
ret
/*********************************************************************************/
.text
.globl map2
map2:
/********************************** prologue *************************************/
pushl %ebp
movl %esp, %ebp
pushl %ebx
pushl %esi
pushl %edi
/********************************************************************************/
movl $0, %ebx
L1: cmpl $16(%ebp), %ebx // error
jge out
movl $12(%ebp), %esi // error
addl %ebx, %esi
movl $8(%ebp), %edi // error
addl %ebx, %edi
/********************************** calls f *************************************/
pushl %eax
pushl %ecx
pushl %edx
pushl (%edi)
call f
movl %eax, (%esi) /* *(another+i) = f(*(one+i)); */
popl %edx
popl %ecx
popl %eax
/********************************************************************************/
/************************************* end **************************************/
popl %edi
popl %esi
popl %ebx
movl %ebp, %esp
popl %ebp
ret
/********************************************************************************/
I'm getting
fmap2.s:44: Error: junk `(%ebp)' after expression
fmap2.s:47: Error: junk `(%ebp)' after expression
fmap2.s:50: Error: junk `(%ebp)' after expression
Why? There is something to do with having 2 prologues and endings in the same file? The base-dislocation numbers of those error lines are correct.
According to gcc documentation, you need to remove dollar signs in front of the numeric constants used for displacement:
One point to bear in mind is that, when a constant is used for disp/scale,
’$’shouldn’t be prefixed.
movl $0, %ebx
L1: cmpl 16(%ebp), %ebx
jge out
movl 12(%ebp), %esi
addl %ebx, %esi
movl 8(%ebp), %edi
addl %ebx, %edi