[solved] optimization/8302: -fno-strict-aliasing was missing

[Yaacov Akiba Slama <ya at slamail dot org>]

Hello,

The following code aborts if "-fstrict-aliasing" is set (and this seems 
to be implied by "-O2") with gcc-3.2 (and newer versions also).
This seems to be the right behavior.
This solves the bug 8302.

// This sample crashes with -fstrict-aliasing (or -O2) but returns 0 
with -fno-strict-aliasing

unsigned char *p;


unsigned char * aux(unsigned char **pBuffer) {
 return *pBuffer + 1;
}

int
test(int a2, unsigned char a3)
{

   unsigned char *Buffer;
   unsigned char * t1;
   unsigned char * t2;

   p = Buffer = (unsigned char *) malloc(30);

   aux(&Buffer);
          
   *(*(( int * * )&Buffer))++ = a2;
      
   t1 = Buffer;

   *Buffer = a3;

   t2 = Buffer; // t2 == t1 when OK.

   return t1-t2; //0 if OK.
}

int main()
{

 int d;

 d = test(0x41414141,'a');

 if (d != 0)
    abort();
 return 0;
}