[Bug tree-optimization/106322] [12/13 Regression] tree-vectorize: Wrong code at O2 level (-fno-tree-vectorize is working) since r12-2404-ga1d27560770818c5
linkw at gcc dot gnu.org
gcc-bugzilla@gcc.gnu.org
Mon Aug 15 06:51:40 GMT 2022
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106322
Kewen Lin <linkw at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
--- Comment #45 from Kewen Lin <linkw at gcc dot gnu.org> ---
One reduced C test case:
#define N 64
typedef unsigned short int uh;
typedef unsigned short int uw;
uh a[N];
uh b[N];
uh c[N];
uh e[N];
__attribute__ ((noipa)) void
foo ()
{
for (int i = 0; i < N; i++)
c[i] = ((uw) b[i] * (uw) a[i]) >> 16;
}
__attribute__ ((optimize ("-O0"))) void
init ()
{
for (int i = 0; i < N; i++)
{
a[i] = (uh) (0x7ABC - 0x5 * i);
b[i] = (uh) (0xEAB + 0xF * i);
e[i] = ((uw) b[i] * (uw) a[i]) >> 16;
}
}
__attribute__ ((optimize ("-O0"))) void
check ()
{
for (int i = 0; i < N; i++)
{
if (c[i] != e[i])
__builtin_abort ();
}
}
int
main ()
{
init ();
foo ();
check ();
return 0;
}
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