http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54362
Bug #: 54362
Summary: COND_EXPR not understood by either alias or ITM
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: pins...@gcc.gnu.org
Take this slightly modified gcc.dg/tm/memopt-12.c :
/* { dg-do compile } */
/* { dg-options "-fgnu-tm -O3 -fdump-tree-tmmark" } */
extern int test(void) __attribute__((transaction_safe));
extern void *malloc (__SIZE_TYPE__) __attribute__((malloc,transaction_safe));
struct large { int foo[500]; };
int f(int j)
{
int *p1, *p2, *p3;
p1 = malloc (sizeof (*p1)*5000);
__transaction_atomic {
_Bool t;
int i = 1;
*p1 = 0;
p2 = malloc (sizeof (*p2)*6000);
*p2 = 1;
t = test();
for (i = 0;i < j;i++)
{
/* p3 = PHI (p1, p2) */
if (t)
p3 = p1;
else
p3 = p2;
/* Since both p1 and p2 are thread-private, we can inherit the
logging already done. No ITM_W* instrumentation necessary. */
*p3 = 555;
}
}
return p3[something()];
}
/* { dg-final { scan-tree-dump-times "ITM_WU" 0 "tmmark" } } */
/* { dg-final { cleanup-tree-dump "tmmark" } } */
--- CUT ---
It currently fails because the aliasing code does not understand that p3 cannot
alias only local memory.
I found this while adding support to phiopt to convert some phi's into
COND_EXPR.
