optimizing inlined switch statements and -fPIC

[David Mansfield <gcc at dm dot cobite dot com>]

I noticed something really weird, and I need to find out if there's a way 
to correct this odd behavior.

I've noticed this with egcs, gcc-2.96 from red hat 7.2, gcc-3.0.1 and 
gcc-3.0.2 (from source).

I have an inline function which performs a switch statement, each switch 
returns a constant value.  When this function is called with a constant 
value, the entire switch COULD be eliminated.  But it isn't in some cases.

1) it works when -fPIC isn't specified
2) it works if there are 3 or less cases and -fPIC is specified

I have a sample .c file, inline.c.

I've been compiling it like:

gcc -O2 -S inline.c
and 
gcc -fPIC -O2 -S inline.c

I'd really like to be able to have the compliler optimize away the switch 
in all cases.

here's the file:

------- cut inline.c -------
#include <stdio.h>

#define VAL_1 1111
#define VAL_2 2222
#define VAL_3 3333
#define VAL_4 4444

#define KEY_1 1
#define KEY_2 2
#define KEY_3 3
#define KEY_4 4

/*
 *
 * if you comment out USE_4_CASES the compiler will
 * properly optimize away the switch statement when 
 * compiled with -fPIC, otherwise it won't
 *
 * when compiled without -fPIC it works in either case
 *
 * complile as: gcc -S -O2 [-fPIC] inline.c and look
 * at the assembly output
 */

#define USE_4_CASES

static __inline__ int get_val(int key)
{
    switch(key)
    {
    case KEY_1: return VAL_1;
    case KEY_2: return VAL_2;
    case KEY_3: return VAL_3;
#ifdef USE_4_CASES
    case KEY_4: return VAL_4;
#endif
    }
}

int func()
{
    printf("%d\n", get_val(KEY_1));
    return 0;
}

---------- end inline.c ---------

Can anyone can tell me anything (is there an __attribute__ I can use?)?

David

-- 
/==============================\
| David Mansfield              |
| david@cobite.com             |
\==============================/