Piotr Mazur

CodeWarrior for ColdFire 7.2 bug ?

Discussion created by Piotr Mazur on Apr 1, 2010
Latest reply on Apr 8, 2011 by Marc Vandenhende

It seems there is again serious problem with peephole optimization in CodeWarrior for ColdFire 7.2

Compilation of simple program:


typedef struct {
    uint32 Start;
    uint32 Length;
} Objects_type;

Objects_type Objects[1024];

int main(void)
int k = 15;

    Objects[k].Length |= 0x80000000;


with peephole "on" and Level1 optimization results in incorrect result:


;   24:     Objects[k].Length |= 0x80000000;
;   25:      
;   26:      
0x00000004  0x41F900000000           lea      _Objects,a0
0x0000000A  0x7207                   moveq    #7,d1
0x0000000C  0x03F01804               bset     d1,(4,a0,d1.l)

The sequence above ignores value of "k" and  modifies beginning of the table.

With the peephole "off" the result  is O.K:

;   24:     Objects[k].Length |= 0x80000000;
;   25:      
;   26:      
0x00000004  0x720F                   moveq    #15,d1
0x00000006  0xE789                   lsl.l    #3,d1
0x00000008  0x41F900000000           lea      _Objects,a0
0x0000000E  0x41F01804               lea      (4,a0,d1.l),a0
0x00000012  0x2210                   move.l   (a0),d1
0x00000014  0x08C1001F               bset     #31,d1
0x00000018  0x2081                   move.l   d1,(a0)

Am I missing something or after all these problems with peephole in 7.1 we got another version of compiler with faulty optimization ?

The CPU tested is M5249C3.