https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61810
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
For
FAIL: gcc.dg/vect/vect-strided-a-u8-i8-gap7.c execution test
it indeed 'makes combine happy' with enabled vs. disabled diff
***************
*** 912,935 ****
(plus:QI (reg:QI 264 [ ivtmp.50 ])
(const_int -3 [0xfffffffffffffffd])))
! Trying 401 -> 186:
Failed to match this instruction:
(set (pc)
! (pc))
! Successfully matched this instruction:
! (set (pc)
! (label_ref 191))
! allowing combination of insns 401 and 186
! original costs 4 + 4 = 0
! replacement cost 4
! deferring deletion of insn with uid = 401.
! modifying other_insn 187: pc=L191
! REG_BR_PROB 9996
! deferring rescan insn with uid = 187.
Trying 193 -> 197:
Failed to match this instruction:
--- 911,923 ----
(plus:QI (reg:QI 264 [ ivtmp.50 ])
(const_int -3 [0xfffffffffffffffd])))
! Trying 186 -> 187:
Failed to match this instruction:
(set (pc)
! (if_then_else (eq (reg/v:QI 255 [ y ])
! (const_int 0 [0]))
! (label_ref 191)
! (pc)))
Trying 193 -> 197:
Failed to match this instruction:
where 'y' is unused and has a set to zero. But this shows an issue with
the testcase which uses uninitialized y to abort(!)
__attribute__ ((noinline)) int
main1 ()
{
int i;
s arr[N];
s *ptr = arr;
s res[N];
unsigned char u, t, s, x, y, z, w;
for (i = 0; i < N; i++)
{
arr[i].a = i;
arr[i].b = i * 2;
arr[i].c = 17;
arr[i].d = i+34;
arr[i].e = i * 3 + 5;
arr[i].f = i * 5;
arr[i].g = i - 3;
arr[i].h = 67;
if (y) /* Avoid vectorization. */
abort ();
}
probably in the others as well. I'm going to fix those.
