This is gcc-4.2.0-0.20060806r115974
Source:
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typedef struct descr *descr_t;
typedef descr_t *value_t;
struct descr {descr_t descr;};
typedef struct {descr_t descr; value_t fields[2];} object_t_2;
value_t **marked_top, **marked_limit;
void gc(void);
object_t_2 pair_12138, list_12140, pair_12196, list_12198, pair_12319,
list_12321, list_12328, pair_12334, pair_12336, record_12376,
pair_12413, list_12415, record_12420;
value_t symbol_7584, symbol_12137, symbol_7525, symbol_11238, symbol_7778,
symbol_12326, symbol_11917, symbol_7927, symbol_7525, symbol_11238,
symbol_12335, CheckArity, symbol_7584, symbol_7583, BadArguments;
static inline void
set_global_field(value_t obj, int i, value_t value) {
value_t *ptr = (value_t *)obj + i + 1;
*ptr = value;
*marked_top++ = ptr;
if (marked_limit < marked_top) gc();
}
int test(void) {
set_global_field(&pair_12138.descr, 0, symbol_7584);
set_global_field(&list_12140.descr, 0, symbol_12137);
set_global_field(&pair_12196.descr, 0, symbol_7525);
set_global_field(&list_12198.descr, 0, symbol_7778);
set_global_field(&pair_12319.descr, 1, symbol_11238);
set_global_field(&list_12321.descr, 0, symbol_7778);
set_global_field(&list_12328.descr, 0, symbol_11917);
set_global_field(&pair_12334.descr, 0, symbol_7525);
set_global_field(&pair_12334.descr, 1, symbol_11238);
set_global_field(&pair_12336.descr, 0, symbol_12335);
set_global_field(&record_12376.descr, 0, CheckArity);
set_global_field(&pair_12413.descr, 0, symbol_7584);
set_global_field(&list_12415.descr, 0, symbol_7583);
set_global_field(&record_12420.descr, 0, BadArguments);
return 0;
}
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When compiled with gcc -S -O2 source.c, the last set_global_field call
generates the following code:
leal 4(%edx), %eax
cmpl marked_limit, %eax
movl BadArguments, %ecx
movl $record_12420+4, (%edx)
movl %eax, marked_top
jbe .L28
movl %ecx, record_12420+4
call gc
.L28:
leave
xorl %eax, %eax
ret
The assignment of BadArguments to the field of record_12420
is performed only in one branch, while it should be done
unconditionally.
Reducing the number of set_global_field calls avoids the bug.
--
__("< Marcin Kowalczyk
\__/ [EMAIL PROTECTED]
^^ http://qrnik.knm.org.pl/~qrczak/
