prashant rawat wrote:
I have a simple C code :
#include<stdio.h>
int *c;
int main ()
{
int a=0, b;
while (a < 100)
{
b = 10;
a = a + 1;
}
c = &b;
printf ("%d\n", *c);
return 0;
}
I would basically expect the b = 10 statement to be moved out of the
while loop, as it is an invariant.
However, it does not seem to happen in the *.lim dump file.
I am using gcc 4.4.2 to compile, and the cmd line options are
install/bin/gcc -fdump-tree-all -O3 filename.c
With gcc 4.5, the b assignment is moved out of the loop at -O, and the
loop is removed entirely at -O3 or -Os.
